JPH06256540A - Production of biological activity inhibiting material - Google Patents

Abstract

PURPOSE:To produce a coating film capable of easily and effectively sterilizing or inhibiting biological activity without requiring a complicated device. CONSTITUTION:To a photoelectric chemical cell of titania powders carrying Ni is mixed 90wt.% tetrafluoroethylene powder, and the mixture is sprayed on a polyester nonwoven fabric surfaces so as to make 50mum film thickness by using a low temperature thermal spray gun. It is possible to sterilize E.coli, etc., or inhibit activity of sphagnum, etc., by this biological activity inhibiting coating film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a bioactivity inhibitor, and more particularly to a bioactivity inhibitor capable of sterilizing various fungi such as Escherichia coli and water moss in an aquarium or inhibiting its activity. Regarding the manufacturing method of.

[0002]

2. Description of the Related Art Conventionally, as a method for sterilizing microorganisms or suppressing their activity, for example, heat sterilization method, ultraviolet sterilization method, cell membrane destruction method by ultrasonic wave, sterilization method using electricity or gas, sterilization method by poisons, Various methods such as a high magnetic field sterilization method and a chemical sterilization method using a halogen-based or surfactant-based agent are used in a wide range of fields.

However, each of the methods for sterilizing microorganisms or suppressing the activity thereof requires a relatively large-scale apparatus, and since the immediate effect is so important, the product itself to which bacteria are attached at the same time as sterilization is used. Often associated with the risk of destruction or damage.

[0004]

SUMMARY OF THE INVENTION The object of the present invention is to solve the above-mentioned problems of the prior art, and without the need for a complicated device, simply by immersing it in an aqueous system in which biological activity is suppressed, it is easy. Another object of the present invention is to provide a method for producing a bioactivity-suppressing material capable of effectively sterilizing or suppressing its bioactivity.

[0005]

SUMMARY OF THE INVENTION The present inventor has found that an optical semiconductor,
For example, when titania (TiO ₂ ) powder is exposed to ultraviolet light in the presence of oxygen, it exhibits the property of decomposing stable hydrocarbons, and the presence of water in the photoelectrochemical cell in which the titania powder carries a metal. Focusing on the fact that when irradiated with ultraviolet light below, it exerts a strong oxidizing power and oxidizes water to generate oxygen, the characteristics of such a photoelectrochemical cell are sterilized by microorganisms or its activity is suppressed. As a result of diligent research for use in the field, a coating formed from a mixture of fluororesin powder in a photoelectrochemical cell supporting a metal on titania particles, when immersed in a water system, various fungi, microorganisms such as water moss, etc. The present invention has been accomplished by finding that the material exhibits bactericidal properties or suppresses its activity, that contaminants such as oil do not easily adhere, and that it is excellent in hydrophobicity and durability.

That is, the first invention of the present application is characterized in that a mixture of a photoelectrochemical cell in which a metal is supported on optical semiconductor fine particles and a fluororesin powder is heated to a temperature not lower than the melting point of the fluororesin to form a film. The present invention relates to a method for producing a biological activity suppressing material. A second invention relates to a method for producing a bioactivity-suppressing material, which comprises spraying a mixture of a photoelectrochemical cell in which a metal is supported on optical semiconductor fine particles and a fluororesin powder onto a surface of a base material to form a coating film.

[0007]

[Function] Ultraviolet light (wavelength: 4) is applied to a film (or a substrate having the film) made of a mixture of a photoelectrochemical cell in which a metal is supported on fine particles of photo-semiconductor, for example, titania and a fluororesin powder.
(00 nm or less), electrons in the valence band of the titania are excited into the conduction band, and holes are generated in the valence band. The holes move to the surface along the potential gradient generated near the surface of titania. The holes have a strong oxidizing power corresponding to the energy of the band gap. Therefore, when water is present on the titania surface by the oxidizing power, the water is oxidized and oxygen is generated. Therefore, when this coating or substrate is immersed in an aqueous system, the active oxygen can suppress the microbial activity or kill the microorganism itself. The electrons excited in the conduction band move to the metal supported on the titania, which is the counter electrode, and reduce water to generate hydrogen.

In the present invention, examples of the optical semiconductor include titania, strontium titanate, potassium niobate and the like. Among them, titania is preferably used. As the titania (tetravalent), a rutile type having a crystal structure can be used, but an anatase type is preferable because it has a large surface area and is more active. In both the photosemiconductor ceramic and the supported metal, the function of suppressing the biological activity is very closely related to the surface area, and therefore, in principle, the thinner the better. The particle size of the titania particles is preferably 0.1 to 60 μm, particularly 1.0 to 10 μm.
It is preferably μm. Examples of the metal supported on the titania particles include conductive metals having low toxicity such as silver (Ag), nickel (Ni), and platinum (Pt).
For example, Ag is preferably used as a bioactivity suppressing material for medical use, and Ni is suitably used as a bioactivity suppressing material for general industry for the purpose of suppressing the generation of water moss.

In the present invention, the method of supporting the metal on the titania particles includes, for example, a physical method utilizing centrifugal force, an electrolytic plating method, a composite coating forming method using ultrafine metal powder, a thermal spraying method, and a metal. A known method such as a method of immersing in a salt solution or a method of immersing in an organic metal such as an alkoxide and then heat-treating can be applied and is not particularly limited. The amount of metal supported is preferably 0.5 to 30% by weight,
Particularly, 5 to 15% is preferable.

The particle size of the fluororesin powder to be mixed with the photoelectrochemical cell in which titania particles carry a metal is not particularly limited as long as a uniform mixture can be formed. The mixing ratio of the fluororesin powder to the titania photoelectrochemical cell is, for example, 5 to 50% by weight, and preferably 10 to 2
It is 0%. In the present invention, a method of heating a mixture of a photoelectrochemical cell in which a metal is supported on titania fine particles and a fluororesin powder (hereinafter sometimes referred to as a raw material mixture) to a temperature equal to or higher than the melting point of the fluororesin to form a film Is
Known film forming methods such as an inflation method, a calendar roll method, a casting method and the like can be mentioned. The thickness of the coating can be appropriately selected depending on the application.

In the present invention, the method of spraying the raw material mixture on the substrate is suitable for forming the coating film of the raw material mixture on the substrate. Thermal spraying can be performed using a spray gun, but it is desirable to use a low temperature thermal spraying device in order to minimize deterioration of the fluororesin in the raw material. As an apparatus of this type, for example, an air curtain is formed by an air jet flow on the outer periphery of a gas frame formed at the tip of a gas nozzle, and a thermal spray material is supplied from the outside of the air curtain to indirectly heat the gas frame. The thermal spray material is softened by applying it to the thermal spray material, and the softened thermal spray material is sprayed onto the surface of the coated base material. To form a strong bond film. As such a low temperature spray gun, for example, France Socie
te Nouvelle de Metallisati
A JET-PMR type gun manufactured by On Industries Co., Ltd. can be given.

The base material is not particularly limited as long as it can form a coating film of the raw material mixture on the surface, and for example, a sheet, a film, a cylinder made of various polymer materials,
Examples thereof include molded products such as ring honeycombs, plates, papers, cloths, non-woven fabrics, fiber laminates (webs), and the like. The fluororesin in the present invention imparts a film-forming property to the raw material mixture, improves the water-repellency and water-repellency of the film or the base material, and also stain resistance, for example, suppresses adhesion of pollutants such as oil, and durability. Work to improve.

The bioactivity-suppressing material produced according to the present invention may be used alone or in combination with other materials,
By immersing or contacting with an aqueous system in which sterilization or biological activity is to be suppressed, it is possible to suppress the activity of microorganisms and the like existing in the system. The fields of application of the bioactivity suppressing material of the present invention include, for example, the following fields.
That is, in the medical field, for example, disinfection of equipment that cannot be sterilized at high temperature, sterilization of disinfectant, application to sterilization of Staphylococcus aureus, etc. in the field of food industry, for example, keeping freshness of tofu etc. Purification, sterilization of food storage containers, application to prevention of rot of edible oil, etc., in the field of biochemicals, for example, seedling raising of plants under aseptic conditions, application to hydroponic cultivation, in the field of general industry, for example cutting oil It can be used as a coating for preventing corrosion of water, prevention of algae generation at water intake and drainage, prevention of water-related pollution, etc., and a coating for suppressing plant activity in all fields such as marine development and general households. By applying the bioactivity suppressing material produced by the present invention to the ship bottom,
It is possible to prevent shellfish and algae from adhering to the ship bottom.

[0014]

EXAMPLES Next, the present invention will be described in more detail by way of examples. Example 1 By the method of forming a composite coating on titania particles of 5 to 15 μm,
A photoelectrochemical cell supporting 10% by weight of Ni was prepared, and 90% by weight of tetrafluoroethylene powder (trade name: Teflon: trademark of DuPont) having a particle size of 1.0 μm or less was mixed with the photoelectrochemical cell. Mix the mixture with SNMI JE
A T-PMR type gun is used to form a coating film by spraying directly on a polyester nonwoven fabric at a temperature of about 3000 ° C. without using a pineder so that the film pressure becomes 50 μm, thereby forming the optical semiconductor cloth of the present invention. did. Cut this and 1
Two optical semiconductor cloths of 3.8 cm × 17.8 cm were obtained.

Then, 1 mg of ammonia nitrogen as nutrients is placed in a water tank (manufactured by Japan Aquarium Industry Co., Ltd.) having a capacity of 7 liters.
/ Liter, phosphorus 0.1mg / liter, algae breed 5m
1 of tap water was added, the two pieces of the optical semiconductor cloth were dipped, and the occurrence of water moss was observed. The water temperature is 1
The temperature was maintained at 9 ° C. ± 1 ° C., and the observation was continued by adding an amount of water corresponding to the reduced amount of water. The aquarium continued to diffuse air by the diffuser. As a result, no water moss was observed even 22 days after the start of observation. On the 22nd day after the start of observation, one piece of opto-semiconductor cloth was removed, and an algae breed was further added.
When ml was added and the observation was continued, the generation of water moss was not recognized even after 18 days. When the remaining photosemiconductor cloth was taken out 40 days after the start of the observation and the observation was further continued, no water moss was observed even after 44 days from the start of the observation.

In this example, it was found that the algal control effect continues even after all the optical semiconductor cloth is extracted. Comparative Example 1 When water moss generation was observed in the same manner as in Example 1 except that the optical semiconductor cloth was not dipped, thin green algae were generated on the air diffuser, wall surface, etc. 6 days after the start of observation. The green color became darker on the 8th day after the start of observation. Twenty-two days after the start of observation, the color of water changed to brown due to the death of algae.

Table 1 shows changes in nutrient salt concentration in water in Example 1 and Comparative Example 1.

[0018]

[Table 1] Note 1) The added NH ₃ —N changed to nitrate nitrogen on the 6th day after the start of the test.

Note 2) On the 12th day after the start of the test, all the nitrogen of Comparative Example 1 was taken up by the algae. From Table 1, it can be seen that in Example 1 in which the optical semiconductor cloth was immersed, the generation of algae was effectively suppressed. Example 2 The optical semiconductor cloth prepared in Example 1 was cut into 5 mm × 5 mm, and Escherichia coli culture solution adjusted to about 10 ⁶ pieces per 1 ml was uniformly inoculated into the optical semiconductor cloth, and 20 to 25 ° C. (room temperature). ), While irradiating with light of 750 to 800 lux (commercial 40w fluorescent lamp), and after a certain time, wash out the surviving bacteria on the test piece with 10 ml of SCDLP (Nippon Pharmaceutical Co., Ltd.),
The number of viable bacteria in this washout solution was measured by the pour plate culture method (35 ° C. for 2 days) using a medium for measuring the number of bacteria, and when converted into the number of viable bacteria per one test piece, it was initially 9.0 ×. 1
0 ⁵ was the number of bacteria after after 0.5 hours was 10 or less.

Comparative Example 2 When the same amount of the bacterial solution as that inoculated to the test piece in Example 2 was dispensed in the same amount in a petri dish, and the same test was carried out by storing the same, the initial test was 9.0 ×. The number of bacteria that was 10 ⁵ was 8.7 × 10 ⁵ after 1 hour and 1.1 × 10 ⁶ after 6 hours,
After 24 hours, the number was 1.1 × 10 ⁶ .

The results of Example 2 and Comparative Example 2 are shown in Table 2.

[0022]

[Table 2] In Example 2, the sterilizing function of the base material electrolessly plated with Ag in order to correct the sterilizing function of Ag carried on the titania particles in the process of manufacturing the optical semiconductor cloth was examined in the same manner as in Example 2. By the way, no definite effect was observed after about 30 minutes.

From the above, it can be seen that the optical semiconductor cloth of Example 2 has a remarkable bactericidal effect on Escherichia coli. Example 3 The raw material mixture used in Example 1 was fed to a melt extruder having a slit nozzle and extruded into a sheet at about 300 ° C.
A sheet-shaped material having a thickness of about 1 mm was obtained. When this sheet-like material was cut into test pieces having the same dimensions as in Example 1 and tested in the same manner as in Example 1, similar test results were obtained.

[0024]

According to the invention described in claim 1 or 2, the present invention has a coating formed by a mixture of a photoelectrochemical cell in which a metal is supported on titania which is a photo-semiconductor fine particle and a fluororesin powder, or the coating. By immersing the base material in the water to be treated or bringing it into contact with the water, excellent bactericidal action and biological activity suppressing action can be obtained, and therefore it can be usefully used as a biological activity suppressing material in various industries.

Front page continuation (51) Int.Cl. ⁵ Identification code Office reference number FI Technical display location A23L 3/26 A61L 2/16 Z 9163-4C C08J 7/04 Z 7/06 Z D06M 15/256 D21H 19 / 10 (72) Inventor Saegusa Mitsui Shipbuilding Co., Ltd. 5-6-4 Tsukiji, Chuo-ku, Tokyo (72) Inventor Tsukasa Sakurada 1391-3 Ogihara, Kamimatsu-cho, Kiso-gun, Nagano Stock Company Shinshu Ceramics

Claims (2)

[Claims] 1. A bioactivity-suppressing material, characterized in that a mixture of a photoelectrochemical cell in which a metal is supported on photo-semiconductor fine particles and a fluororesin powder is heated to a temperature not lower than the melting point of the fluororesin to form a film. Manufacturing method. 2. A method for producing a bioactivity-suppressing material, which comprises spraying a mixture of a photoelectrochemical cell in which a metal is supported on photo-semiconductor fine particles and a fluororesin powder onto a surface of a base material to form a coating film.