JP7090353B2 - Photocatalytic composition - Google Patents

Description

The present invention relates to a photocatalytic composition.

Recently, from the viewpoint of preventing infections such as infectious diseases, inactivation of viruses for frequently touched items such as tables, doorknobs, and daily necessities has been encouraged. Such virus inactivation work is generally performed by applying and spraying an alcohol disinfectant or a chlorine bleach.

Alcohol disinfectants and chlorine bleach inactivate the virus by destroying the virus membrane. Alcohol disinfectants and chlorine bleach inactivate the virus that was attached to the object when working, but the effect is not persistent. Therefore, it is necessary to work on the newly attached virus after that, and it is necessary to work frequently to prevent the infection of infectious diseases.

JP-A-2015-205254

The photocatalytic composition described in Patent Document 1 is said to have a high virus inactivating action and an antibacterial action continuously when irradiated with light. Since the virus inactivating action and the bactericidal action of such a photocatalyst composition extend to viruses and bacteria attached after the photocatalyst composition is applied, sprayed, or the like, the demand for it has been increasing recently.

However, since the photocatalyst needs to be irradiated with light after being constructed, it may take time to exert its effect depending on the conditions of the construction target. Further, since the photocatalyst composition is almost odorless, it is difficult for a person who does not know that the photocatalyst has been applied to realize the effect at the time of construction. Therefore, a person who does not know that the photocatalyst composition has been applied may repeat unnecessary disinfection work and the like. Further, some components of the disinfectant are toxic to the human body, and even if the construction is performed on a place where an infant touches, the construction side is required to have a high safety and easy handling.

The present invention has been proposed in view of such circumstances, and an object thereof is an easy-to-handle photocatalyst composition having high antibacterial and deodorant properties, yet also having immediate effect and safety. Is to provide.

In order to achieve the above object, the photocatalytic composition of the present invention contains a mixed solution containing water and photocatalytic particles and a water-insoluble cypress oil, and the hinoki oil is 5 to 20 based on the total weight. It is characterized by being contained in% by weight.

Since the photocatalyst composition of the present invention has the above-mentioned structure, it is easy to handle because it has high antibacterial and deodorant properties, but also has immediate effect and safety.

(A) to (c) show the test results of the antibacterial comparative test of hinoki cypress oil, and all of them are photographs taken from above of a petri dish. (A) to (c) show the test results of the antibacterial comparative test of hinoki cypress oil, and all of them are photographs taken from above of a petri dish. (A) to (c) show the test results of the antibacterial comparative test of hinoki cypress oil, and all of them are photographs taken from above of a petri dish. (A) and (b) show the test results of the antibacterial comparative test of hinoki cypress oil, and both are photographs of a petri dish taken from above. It shows the test result about the blending amount of cypress oil, and all of them are photographs taken from above of the petri dish. It shows the test result about the blending amount of cypress oil, and all of them are photographs taken from above of the petri dish.

Hereinafter, the present embodiment will be described in detail.
The photocatalyst composition according to the present embodiment contains a mixed solution containing water and photocatalyst particles and a water-insoluble cypress oil, and the hinoki oil is contained in an amount of 5 to 20% by weight based on the total weight. It is characterized by that. Hereinafter, it will be described in detail.

<Photocatalytic composition>
The photocatalytic composition refers to a composition that absorbs irradiation with ultraviolet rays or visible light to cause a catalytic reaction. As the photocatalytic particles, titanium oxide having an average particle size of 250 nm or less is preferable, and titanium oxide having an average particle size of 200 nm is preferable. It is preferably used. In addition, as the photocatalyst particles, iron oxide, zinc oxide, tungsten oxide, bismuth oxide and the like may be used.
The average particle size is calculated by measuring the length of any 100 particles in a 200,000-fold field of view with a scanning electron microscope. As the electron microscope, for example, S-4800 Scanning Electron Microscope manufactured by Hitachi High-Technologies Corporation is used to image the photocatalyst fine particles to be measured, and the obtained image is image-processed to calculate the particle size. The smaller the average particle size of the photocatalytic particles, the better the adhesiveness to the coated surface and the longer the effect lasts. Further, if the average particle size of the photocatalyst particles exceeds 250 μm, the adhesiveness to the coated surface is insufficient, and the sustainability of the effect after construction tends to decrease.

<Cypress oil>
The hinoki cypress family has been used as a building material for a long time, and in recent years, it has been used as an aroma oil and as a decorative leaf for cooking, etc., but the present inventor has made a mixture containing at least water and photocatalyst particles. By adding hinoki essential oil extracted from cypress or hinoki essential oil extracted from cypress to the liquid, the immediate effect of cypress oil compensates for the slow effect of the photocatalyst, and the aromatic component of hinoki oil realizes that the photocatalyst was constructed. We have invented the photocatalyst composition of the present embodiment which is easy to use. Examples of the liquid obtained by extracting from hinoki and hiba include purified water (distilled water) in addition to essential oil, and it is said that purified water also has a sterilizing effect. Gender has also been reported. However, as a result of various tests, hinoki cypress and cypress essential oils that do not contain water-soluble components extracted from hinoki and cypress have antibacterial performance and immediate effect comparable to hypochlorous acid and alcohol-based disinfectants. It was found that it is suitable for inclusion in the above mixed solution. Furthermore, there are various refining methods for essential oils called essential oils, such as steam distillation methods, and since natural raw materials are used, it has been difficult to select and confirm hinoki cypress oils that can stably exert their effects. Therefore, the present inventor has found that it is effective to use hinoki cypress oil having a value measured by an ATP wiping tester of 130 RLU (Relative Light Unit) or less. The lower the lower limit of the above value of hinoki cypress oil, the more desirable it is, but the photocatalyst exerts its effect later. It can be said that it is suitable. If the value measured by the ATP wipe inspection device exceeds 130 RLU, it tends to be difficult to exert the effect of compensating for the delayed effect of the photocatalytic action of cypress oil. As the ATP wiping tester, a luminometer manufactured by Hygiena, LLC or a Lumitester (registered trademark) manufactured by Kikkoman Biochemifa Co., Ltd. may be used. The ATP wiping tester changes ATP (adenosine triphosphate) to AMP (adenosine triphosphate) by reacting luciferase (enzyme) in the presence of luciferin and oxygen, and the enzymatic reaction at that time is bioluminescence. Since it emits light, it is possible to quantify invisible stains and inspect the cleanliness by measuring the amount of light emitted by ATP. ..

<Photocatalytic composition>
<Mixed liquid>
The mixed liquid constituting the photocatalyst composition is produced by containing 97 to 99% by weight of purified water and 1% by weight of the above photocatalyst particles. In the following evaluation test, titanium oxide having an average particle size of 150 to 200 nm was used as the photocatalytic particles, and a mixed solution of 99% by weight of water and 1% by weight of titanium oxide was used.
<Antibacterial test of mixed solution>
Antibacterial Product Technology Association Antibacterial power evaluation test method for antibacterial processed products Test method III (2003 version) Based on the light irradiation film adhesion method, the test piece to which the above mixed solution was applied was stored under dark and light conditions for 24 hours. The viable cell count was measured. The test strain used was Staphylococcus aureus NBRC 12732 (liquid inoculation volume: 0.2 ml). One black light 20W (FL20S BLB manufactured by Toshiba Corporation) was used as the light source under bright conditions. As a result of the measurement, 200,000 Staphylococcus aureus increased to 780,000 in the dark condition after 24 hours, and decreased to 1400 in the light condition. From this, it was found that the mixed solution showed high antibacterial properties after 24 hours under bright conditions.

<Ammonia odor / formaldehyde deodorant test of mixed liquid>
The above deodorant test was conducted by requesting the Boken Quality Evaluation Organization. A 5-liter Tedlar bag in the test container was filled with 3 liters of each gas, and gas was measured by the detector tube method (test sample 30 ml) at room temperature of 20 ° C. in the test room. It was confirmed that when the initial concentration of ammonia was 100 ppm, it was 0.2 ppm after 2 hours and less than 0.2 ppm after 24 hours. It was confirmed that the initial concentration of formaldehyde was 15 ppm, but it was 0.05 ppm or less after 2 hours and 24 hours. From this, it was found that the mixed solution has a function of decomposing and deodorizing ammonia and formaldehyde.

<Antibacterial test of cypress oil>
Next, a comparative test in which a hinoki cypress oil suitable for adding immediate effect to a mixed solution having high antibacterial and deodorant properties under the above-mentioned bright conditions was found will be described. For this test, we provided various test solutions containing hinoki cypress as the main component to Professor Nagatoshi Fujiwara, Faculty of Contemporary Life Studies, Tezukayama University, and requested that an antibacterial evaluation test be conducted.

Hiba essential oil and Hiba purified water used in the test solution were requested to be refined by FEC Co., Ltd. (19-10 Oishi-cho, Aioi City, Hyogo Prefecture) by extracting Hiba oil at low temperature and in a vacuum state. .. As a raw material, 29.2 kg of Hiba with a water content of 39.2% was used, the drying time was 7 hours, the dry weight was 18.0 kg, the water content of the dried product was 1.4%, and 65 g of Hiba essential oil and 11.2 L of Hiba purified water were obtained. rice field. Then, we prepared the ones made mainly using the branches and stems and the ones made mainly using the leaves.

The hinoki essential oil and hinoki purified water used in the test solution were also refined by a method of extracting hinoki oil at a low temperature and in a vacuum state by requesting FEC Co., Ltd. As a raw material, 50.15 kg of hinoki with a water content of 57.2% was used, the drying time was 8 hours, the dry weight was 21.9 kg, the water content of the dried product was 1.9%, and 65 g of hinoki essential oil and 28.25 L of purified cypress water were obtained. rice field. Then, we prepared the ones made mainly using the branches and stems and the ones made mainly using the leaves.

Then, using these hinoki essential oil, hinoki purified water, hinoki essential oil, hinoki purified water, and a mixed solution, a test solution was prepared below and the test described later was performed.
No1 ・ Hiba essential oil + Japanese cypress purified water A (mainly extracted from branches and stems)
No2 ・ Hiba essential oil + Japanese cypress purified water B (mainly extracted from the leaves)
No3 ・ Hinoki essential oil (mainly extracted from branches and stems)
No4 ・ Hiba essential oil (mainly extracted from the leaves)
No5 ・ Hinoki purified water A (mainly extracted from branches and stems)
No6 ・ Hinoki purified water B (mainly extracted from leaves)
No7, Hiba purified water No8, Hiba purified water + Hinoki purified water (mainly extracted from the branches and trunks) + Mixture No9, Hiba purified water + Hinoki purified water (mainly extracted from the leaves) ＋ Mixture No10 ・ Hinoki leaf essential oil (mainly extracted from the leaves)
No11 ・ Mixed liquid only

50 μl of the above No. 1 to No. 10 test solutions was applied to a petri dish, and A. 10 μl (for example, the right side of FIG. 1 (a)) and B. 20 μl (for example, the left side of FIG. 1 (b)) were applied to an Advantech filter paper having a diameter of 6 mm. After inoculating the cocci and culturing for 24 hours, the inhibition circle measurement of Staphylococcus aureus was performed and the growth was evaluated. As a result, the above-mentioned No3, No4, and No10 were found to have an effect of suppressing the growth of bacteria (see FIGS. 1 (c), 2 (a), and 4 (a)). In other cases, bacterial growth was observed. From this, it was found that not all hinoki cypress-derived substances have antibacterial properties, but that water-insoluble cypress oil has immediate antibacterial properties. Further, since No. 11 was not irradiated with light, the antibacterial property could not be confirmed from the result of the blocking circular measurement.

Therefore, 50 μl of the above No3, No4, and No10 were further applied to the petri dish, and Staphylococcus aureus was applied. Viable cell count The cells were stored at 37 ° C. for 2 days, and the bacterial count was measured. At the start of the test, when the viable cell count was 37, the viable cell count did not increase in No. 3 and No. 4, and the growth inhibition rate was 100%. In No. 10, the viable cell count increased by 4, and the growth inhibition rate was 89%. As a result, it can be said that No3, No4, and No10 have antibacterial persistence even when stored at 37 ° C. for 2 days.

Next, a test was conducted on the blending amount of the above 11 mixed solution and hinoki cypress oil.
Mix the above 3 and the above 11 and the above 4 and the above 11 at a ratio of 1: 9, 2: 8, 3: 7, apply 50 μl to a petri dish, and add Escherichia coli, Staphylococcus aureus and Escherichia coli to an Advantech filter paper with a diameter of 6 mm. After inoculating 5 μl and 10 μl and culturing for 24 hours, inhibition circle measurement was performed and growth evaluation was performed. FIG. 5 shows an example of the above No. 3 and the above 11 and FIG. 6 shows an example of the above No. 4 and the above No. 11. As a result of the test, even with a ratio of 1: 9, inhibition circle formation was confirmed, and inhibition of bacterial growth was confirmed. From this result, it can be said that if the content of hinoki cypress oil is 8% by weight or more based on the weight of the total solid content, a photocatalytic composition having an immediate antibacterial action can be obtained. Further, from this test result, sufficient antibacterial activity could be confirmed by mixing at a ratio of 2: 8 or more. Therefore, more preferably, if the content of hinoki cypress oil is 20% by weight or more based on the weight of the total solid content, the effect of the mixed solution combined with the antibacterial action and the deodorizing action of the photocatalyst originally possessed is obtained. It will play. The values of No3, No4, and No10 used at this time were extremely low, 14 RLU for No3 and 17 RLU for No4, as measured by an ATP wipe inspection device (using a Lumitester (registered trademark)). In addition, No10 is 127 RLU, which is also higher than No3 and No4, and is sufficiently low considering the above-mentioned management standard values for cooking utensils, etc., and both are ATP wipe inspection devices (Lumitester (registered trademark). ) Was used) and the value measured in) was 130 RLU or less.

<Comparative evaluation test using ATP wipe inspection device>
Next, an evaluation test using an ATP wipe inspection device was performed.
First, the following test solutions are prepared as examples and comparative examples.
<Example>
90% by weight of the mixed solution and 10% by weight of the hinoki cypress oil of No. 3 were mixed to obtain a test solution of Examples.
<Comparison example>
The above No. 11 containing no cypress oil was prepared.

As an ATP wiping tester, the above-mentioned Lumitester (registered) manufactured by Kikkoman Biochemifa Co., Ltd., which measures the total amount of ATP (adenosine triphosphate), ADP (adenosine diphosphate), and AMP (adenosine monophosphate). Using (trademark), the test solution was applied to the test object, and changes before and after construction were evaluated.

The test procedure is as follows.
Wipe the surface of the test object with a cotton swab wet with tap water to obtain a sample. The sample is then reacted with the luciferase reagent. The amount of luminescence when the sample reacts with the luciferase reagent is measured.

The test targets are a wooden desk top plate (hereinafter referred to as "wooden desk"), a marble table top plate (hereinafter referred to as "marble table"), a metal doorknob lever part (hereinafter referred to as "doorknob"), and cowhide. The surface of the cover of the notebook made of wood (hereinafter referred to as "notebook cover") and the bowl part of the washstand made of earthenware (hereinafter referred to as "washstand").
1) Measure the numerical values of the test objects before construction in the examples and comparative examples.
2) An example and a comparative example are applied to each test object.
3) Measure the value immediately after construction.
4) Measure the value again three days after construction.

The results of the above evaluation tests are shown in Table 1.
The RLU (Relative Light Unit), which is a numerical unit in Table 1, indicates the amount of light emitted when the sample reacts with the luciferase reagent. The larger this value is, the larger the amount of ATP, ADP, and AMP is, which means that the substance is contaminated. It can be said that the lower the value after construction is, the better the bactericidal and antibacterial performance is.

The numerical values immediately after construction of each test object are smaller than those before construction in both Examples and Comparative Examples. In particular, the numerical values of the examples immediately after the construction of each test target were lower than the numerical values of the comparative examples immediately after the construction. It is considered that this is because the cypress extract contained in the examples is sterilized and antibacterial to the test object immediately after the construction. The figures after three days are smaller than the figures immediately after construction in both the examples and the comparative examples for the wooden desk and the notebook cover. It can be said that the photocatalytic reaction of the photocatalyst contained in the sample progresses in both the examples and the comparative examples, and the photocatalyst is sterilized and antibacterial. For marble tables, doorknobs, and wash basins, the values three days after construction exceeded the values immediately after construction. The Lumitester (registered trademark) used for the measurement measures the numerical value of ATP and the like contained in the cells, and the test subject was used in daily life immediately after the construction. Therefore, it is considered that the user's sebum, skin pieces, etc. adhered and were reflected in the numerical value.

From the comparative evaluation test using the above ATP wiping tester, the photocatalyst composition according to the present embodiment exhibits antibacterial and other effects due to the immediate effect of hinoki cypress oil extracted from cypress immediately after construction. In addition, since the photocatalyst composition contains cypress oil, the fragrance component of the photocatalyst composition causes the scent of cypress to drift in the construction space, which makes it easier to feel the construction. It can be said that.

As mentioned above, from <Antibacterial test of mixed solution> <Ammonia odor / formaldehyde deodorant test of mixed solution>, it can be confirmed that the mixed solution has high antibacterial and deodorant properties, and in addition to this, < Antibacterial test of hinoki oil> revealed that water-insoluble hinoki essential oil, hiba essential oil, and hinoki leaf essential oil have extremely high antibacterial properties. From the <evaluation test using an ATP wipe tester>, it was confirmed that the photocatalyst composition containing hinoki cypress oil had a higher immediate effect than the mixed solution alone. The photocatalyst composition according to the present embodiment is made of only components that are safe for the human body, and can be said to be highly safe and easy to handle for both the construction side and the user side.

Claims (4)

A photocatalytic composition containing a mixed solution containing water and photocatalytic particles and a water-insoluble cypress oil, wherein the hinoki oil is contained in an amount of 5 to 20% by weight based on the total weight. In claim 1,
The photocatalytic composition is characterized in that the cypress oil is any one of hinoki essential oil, hiba essential oil, and hinoki leaf essential oil. In claim 1 or 2,
The hinoki cypress oil is a photocatalytic composition characterized in that the value measured by an ATP wiping tester is 130 RLU or less. In any one of claims 1 to 3,
The photocatalyst particles are a photocatalyst composition having an average particle size of 250 nm or less, which is titanium oxide.

Images