JP2001314198A - Test method for evaluation of fungicidal performance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a test method for the evaluation of fungicidal performance, by which good repeatability can more easily be obtained than by conventional methods for the evaluation tests of the fungicidal performance and by which the fungicidal performance can be evaluated in a short time. SOLUTION: This test method for the evaluation of the fungicidal performance, characterized by tightly bringing the bottom portion of a cylindrical member having at least an opening in the bottom portion into contact with a target material for the evaluation test of the fungicidal performance, charging a liquid containing a fungal spore suspension into the cylindrical member, incubating the fungal spores, and then evaluating the fungicidal performance of the evaluation test target material on the basis of the fungus growth state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a method for evaluating and testing mold-proofing performance, and more particularly to a method for evaluating and evaluating mold-proofing performance of materials used for building materials, electric appliances, furniture, automobile parts and the like. Belongs to the technical field.

[0002]

2. Description of the Related Art As an evaluation test method of mold prevention performance, J
An evaluation test method (mold resistance test method) specified in IS Z 2911 is known. In this method, a mold spore suspension is applied to the surface of a test piece or a sample (hereinafter, referred to as a test piece) of a material to be subjected to an evaluation test of mold prevention performance, and a mold spore suspension is applied to a surface area of the test piece of 30 mm × 30 mm. 0.5ml
And inoculation by spraying with a sprayer or a pipette, and culturing for 2 weeks or 4 weeks to evaluate the antifungal performance (mold resistance) according to the growth state of the mycelium on the surface of the test piece.

[0003]

However, in the conventional test method for evaluating antifungal performance (mold resistance test method), in order to obtain data having good reproducibility and excellent reliability, it is necessary to use a test method. Good reproduction because it is necessary to control the ratio of the mold spore suspension to the surface area of the piece, the uniformity when spraying, and the humidity control when culturing for a long time (2 weeks or 4 weeks) with good reproducibility. However, there is a problem that it is not easy to obtain reproducibility and it is difficult to obtain good reproducibility. For example, if the homogeneity of the fungal spore suspension is insufficient, the fungal spore suspension will be concentrated in one place, thus reducing the reliability of the test results, Insufficient humidity control results in drying during cultivation, and thus, even for the test material without the antifungal property, the growth of hyphae is not recognized, resulting in incorrect test results. There are points.

Further, in the above-mentioned conventional test method for evaluating antifungal performance, the cultivation time is as long as two weeks or four weeks, and it takes a long time to evaluate the antifungal performance, so that the antifungal performance can be evaluated more quickly. The emergence of a performance evaluation test method is desired.

The present invention has been made in view of such circumstances, and it is an object of the present invention to easily obtain good reproducibility as compared with the conventional method for evaluating the antifungal performance. It is an object of the present invention to provide a method for evaluating the antifungal performance. Still another object is to easily obtain good reproducibility and to evaluate the antifungal performance in a short time.

[0006]

In order to achieve the above object, a method for evaluating the antifungal performance according to the present invention is a method for evaluating the antifungal performance according to claims 1 and 2, which is as follows. The configuration is as follows.

That is, in the method for evaluating the antifungal performance according to the first aspect of the present invention, a cylindrical member having an opening at least on the bottom is brought into close contact with the material to be evaluated for the evaluation of the antifungal performance, with the bottom facing downward. After placing a liquid material containing a mold spore suspension inside the cylindrical member, culturing is performed, and the mold prevention performance of the target material for the evaluation test is evaluated based on the growth state of the mold. This is a mold performance evaluation test method (first invention).

According to a second aspect of the present invention, there is provided the test method for evaluating the antifungal performance according to the first aspect of the present invention.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is embodied in the following manner, for example. A cylinder having openings at both ends (top and bottom) is placed on the target material of the antifungal performance evaluation test (hereinafter referred to as an evaluation test target material) with the bottom part facing down,
After putting the liquid containing the mold spore suspension inside this tubular member, cultivate for a certain period, observe the growth of the mold,
The mold prevention performance of the evaluation test material is evaluated based on the growth state of the mold.

A more specific example will be described below. Vacuum grease is applied to one end surface of the cylindrical ring, and the ring is placed in close contact with a plate-like evaluation test material placed in a sterile petri dish with the end surface of the ring facing down. Next, a liquid containing a mold spore suspension is put into the ring. Then, the liquid material uniformly spreads on the material to be evaluated in the ring. Next, the sterilized petri dish is covered. Thereafter, the cells are cultured at a constant temperature for a constant period.
Then, the growth status of the mold is observed, and the antifungal performance of the evaluation test target material is evaluated based on the growth status of the mold. The present invention is implemented in such a form.

Hereinafter, the function and effect of the present invention will be mainly described.

[0012] The method for evaluating the antifungal performance according to the present invention comprises:
As described above, a cylindrical member having an opening at least in the bottom portion is placed in close contact with the material to be subjected to the evaluation test of the antifungal performance (hereinafter, referred to as an evaluation test material) with the bottom portion facing down,
After the liquid material containing the mold spore suspension is put into the inside of the cylindrical member, it is cultured and the mold prevention performance of the evaluation test target material is evaluated based on the growth state of the mold (first invention).

As described above, since the cylindrical member is placed in close contact with the material to be evaluated, the container is formed by the material to be evaluated and the cylindrical member. Since the liquid containing the mold spore suspension is put into the inside of the cylindrical member (that is, in the container), the liquid is placed on the material to be evaluated in the cylindrical member. That is, it spreads uniformly on the bottom of the container).

Therefore, the ratio of the liquid (liquid containing the mold spore suspension) to the surface area of the material to be evaluated can be easily made constant, and the reproducibility of the ratio is good. In addition, the liquid material has excellent uniformity on the evaluation test target material, and its reproducibility is good. Further, the liquid material is hardly dried during the culture, the humidity is easily controlled during the culture, and the reproducibility is good. At this time, a lid can be placed on the cylindrical member,
Then, it becomes easier to prevent the liquid from drying and to control the humidity.

Therefore, according to the test method for evaluating antifungal performance according to the present invention, it is extremely easy to obtain good reproducibility as compared with the conventional test method for evaluating antifungal performance. That is, it is possible to extremely easily obtain data having excellent reproducibility and excellent reliability.

Further, according to the test method for evaluating the antifungal performance according to the present invention, the amount of the liquid (liquid containing a mold spore suspension) can be increased, and the amount of the liquid during the culture can be increased. Due to the fact that the mold does not dry, the mold growth rate is higher than in the case of the conventional test method for evaluating antifungal performance, and the antifungal performance can be evaluated in a short time.

That is, in the case of the conventional test method for evaluating the antifungal performance, as described above, a mold spore suspension is sprayed on the surface of a test piece (a test piece or a sample of a material to be evaluated) with a sprayer or a pipette. The amount of the mold spore suspension on the surface of the test piece is originally small because it is inoculated by the method of multiplication, so it is difficult to increase the number of mold spores at the time of inoculation, and the wet state is almost dry. Therefore, the growth rate of the mold is slow, and it takes a long time to evaluate the antifungal performance. It is to be noted that the mold may be dried in the middle of the culture and cultured in a state closer to the dry state, and in this case, the growth rate of the mold is further reduced.

On the other hand, in the case of the test method for evaluating the antifungal performance according to the present invention, as described above, the liquid material (the liquid material containing the mold spore suspension) is placed in the cylindrical member. Can be increased, the number of mold spores can be increased at the time of inoculation, and a liquid layer is formed on the evaluation target material, so that the liquid does not dry, The cultivation can always be carried out in a moist condition that is convenient for mold growth. Therefore, the mold growth rate is higher than in the case of the conventional test method for evaluating fungicide performance, and the fungicide performance can be evaluated in a short time.

When the liquid (liquid containing a mold spore suspension) contains a medium in addition to the mold spore suspension, the growth rate of the mold is further increased, and the fungicide can be prevented in a shorter time. The performance can be evaluated (second invention). This is because nutrients for mold growth are added by the inclusion of the above-mentioned medium, and thus the mold growth rate is further increased. At this time, the growth rate of the mold becomes extremely high as in the case of normal mold culture on a medium.

When the liquid containing the mold spore suspension contains a medium, the nutrients in the medium are almost dry during the test period according to the conventional test method for evaluating antifungal performance. Is in a state where it is difficult to take in. On the other hand, in the method for evaluating the antifungal performance according to the present invention, a layer of the liquid material is formed on the material to be evaluated, so that the nutrients are uniformly dispersed in the liquid material, and furthermore, the mold is a nutrient. It is in a state convenient for taking in. For this reason, when the liquid material contains a medium, the fungicide performance evaluation test method according to the present invention can obtain a higher mold growth rate than the conventional fungicide performance evaluation test method.

When the liquid containing the mold spore suspension contains a medium as described above, it is not only easy to obtain good reproducibility, but also the antifungal performance is evaluated in a very short time. Will be able to do so.

In the present invention, the cylindrical member having an opening at least at the bottom means a cylindrical member having an opening at the bottom. The shape of the opening is not particularly limited as long as it can be brought into close contact with the material to be evaluated when the bottom of the tubular member is placed on the lower side. That is, it is not necessary that the entire bottom of the tubular member be open, and it may be partially open, for example. Further, when the material to be evaluated is a flat plate, the bottom of the cylindrical member may be a flat surface in close contact with the plate, and when the material to be evaluated has a curved surface, The bottom of the member may have a curved shape so as to be in close contact with the curved surface.

The tubular member is placed in close contact with the material to be evaluated, with the bottom part facing down, and a liquid containing a mold spore suspension is placed inside the tubular member. The entrance of the liquid material is not limited to being at the upper part of the tubular member, but may be provided at the peripheral wall of the tubular member.

The shape of the cylindrical member is not particularly limited. For example, a cylinder having a circular or elliptical cross section, a rectangular cylinder having a rectangular cross section, or the like can be used. . Also, the size of the cylindrical member is not particularly limited. For example, a cylindrical member having an inner diameter of 2 cm and a height of 1 cm can be used.

The constituent material of the tubular member is not particularly limited, and for example, glass, metal, plastic, etc. can be used.

It is desirable that the material to be evaluated and the bottom of the tubular member are firmly adhered to each other so that no liquid leakage occurs. The means for such contact is not particularly limited, and for example, a method of using vacuum grease, an adhesive, or the like to make contact can be used.

In the present invention, the material of the material to be evaluated is not particularly limited. For example, glass, metal, wood, plastic, etc. can be used as the material to be evaluated.

The material to be evaluated is usually a test piece or a sample cut out of a material whose antifungal property is to be evaluated.
The present invention is not limited to this, and the material itself or the actual material whose antifungal property is to be evaluated can be used as the evaluation test target material.

The shape of the material to be evaluated is not particularly limited. For example, a plate-shaped or pipe-shaped material can be used as the material to be evaluated. When the material to be evaluated is a flat plate, the bottom of the tubular member may be a plane that is in close contact with the plate, and this plane is perpendicular to the center axis of the tube. May also be inclined. When the material to be evaluated is not a flat plate but a plate having a curved surface, the bottom of the tubular member may have a curved shape so as to be in close contact with the curved surface. Further, when the material to be evaluated is a pipe, the bottom of the tubular member may have a shape having a concave portion that is in close contact with the surface of the pipe.

In the present invention, the type of mold in the mold spore suspension is not particularly limited, and examples thereof include Aspergillus, Penicillium, Rhizopas,
Those belonging to the genus Cladosporium or the genus Ketomium can be used.

The temperature of the culture is preferably 25 to 30 ° C., which is a temperature at which mold can easily grow, but is not limited to this.

When the liquid containing the mold spore suspension contains a medium, the medium is not particularly limited, and any medium can be used as long as the mold can grow. Examples of such a medium include a potato dextrose liquid medium and a potato dextrose agar medium. When an agar medium is used, agarose can be used instead of agar. The concentration of agar or agarose is not particularly limited, but is preferably 0.5 to 2% (% by mass), which is a concentration usually used as a growth medium for mold.

The amount of the liquid material containing the mold spore suspension added to the cylindrical member is not particularly limited, but the thickness (depth) of the material to be evaluated is 0.5 to 2m
It is desirable to set the amount to be m. This is because, when the amount is smaller than this (the depth of the liquid is less than 0.5 mm), it is difficult to spread the liquid uniformly. On the other hand, when the amount is more than this (the depth of the liquid is more than 2 mm), the evaluation test is performed. This is because the distribution of the distance from the surface of the material to the individual mold spores is large, making it difficult to perform an accurate evaluation. The amount of the above liquid material is, for example, 0.3 ml in a glass ring having an inner diameter of 2 cm.
Is obtained when a liquid material is added. The amount of addition is the same when the liquid contains a medium and when it does not.

The cultivation time is 2 to 2 as in the case of the conventional test method for evaluating the antifungal performance, because the growth rate of the mold is higher than that of the test method for evaluating the antifungal performance in the related art. It is not necessary to set it to four weeks, but it can be made shorter in this time, for example, it can be made two to three days.
For this reason, the antifungal performance can be evaluated in a short time. That is, for example, after 48 hours and 72 hours of cultivation, the growth status of the mold may be observed, and the antifungal performance of the evaluation target material may be determined.

The criteria for judging the antifungal performance are not particularly limited and may be determined according to the purpose.
For example, the following six-step evaluation method can be adopted.

[Six-step evaluation] 1: Spores are generated on the entire surface. 2: State between 1 and 3 below. 3: Spores are slightly observed. 4: No spores were generated, but hyphal growth was observed on almost the entire surface. 5: No spores were generated, but growth of hypha was slightly observed. 6: No generation of spores and no growth of hypha are observed.

In the case of the test method for evaluating the antifungal performance according to the present invention, a large amount of the liquid material (the suspension of the fungal spores) was placed on the material to be evaluated in comparison with the conventional test method for evaluating the antifungal performance. Therefore, in the state where the surface of the evaluation test target material is sufficiently wet and the nutrients for mold growth are sufficient, the liquid near the surface is gradually removed from the surface of the evaluation test target material. It can be said that the extent to which mold growth is inhibited by components eluted into the body is being examined.

[0038]

(Example 1) An aluminum plate material coated with a mildewproof coating and an aluminum plate material not coated with a mildewproofness were subjected to an evaluation test of the mildewproofing performance, and the effect of the mildewproof coating was evaluated. Confirmation was made. The details will be described below.

On a potato dextrose agar medium 28
5 spores of Aspergillus niger spores cultured at 7 ° C. for 7 days are scraped with 10 ml of 0.005% (% by mass).
Dioctyl sodium sulfosuccinate (a type of agent for uniformly dispersing spores) was added to water and suspended to obtain a mold spore suspension.

Potato dextrose agarose medium kept at 40 ° C. (agarose concentration: 0.7% by mass)
0.2 ml of the mold spore suspension was added to 50 ml and mixed to obtain a liquid containing a mold spore suspension and containing a medium (hereinafter referred to as a mold spore suspension medium).

A 3 cm square aluminum plate was cut from the aluminum plate to be evaluated. After placing this aluminum plate material in a petri dish, a glass cylindrical ring (inner diameter: 2 cm, height: 1 cm) (cylinder having openings at the top and bottom)
Vacuum grease was applied to one end face (bottom part) of the sample, and the ring was placed on an aluminum plate material in the petri dish with the end face of the ring facing down and brought into close contact.

Next, 0.3 ml of the mold spore suspension medium was placed in the ring, and the mold spore suspension medium was shaken and spread so that the thickness (depth) became constant. Next, the petri dish was immediately covered with a lid. Then, the cells were cultured at 28 ° C. for 72 hours, and after 48 hours and 72 hours of the culture, the growth status of the mold was observed, thereby evaluating the mold-preventive performance. At the time of this evaluation, the above-described method of evaluating in six steps was adopted as an evaluation standard. That is, the following six-step evaluation method was adopted. In order to evaluate the reproducibility of the test, n = 3 (the number of repetitions of the test) was set to n.

[Six-step evaluation] 1: Spores are generated on the entire surface. 2: State between 1 and 3 below. 3: Spores are slightly observed. 4: No spores were generated, but hyphal growth was observed on almost the entire surface. 5: No spores were generated, but growth of hypha was slightly observed. 6: No generation of spores and no growth of hypha are observed.

Table 1 shows the results of the above evaluation tests. As can be seen from Table 1, the evaluation test results of the antifungal performance under the same conditions did not vary, and the reproducibility was extremely excellent.

As can be seen from Table 1, in the case of the aluminum plate material which was not coated with the fungicide, the growth of the mold was observed over time, and spores were generated on the entire surface after 72 hours of the culture. On the other hand, in the aluminum plate material coated with the fungicide, neither generation of spores nor growth of hypha was observed even after 72 hours of culture, and no growth of mold was observed. Therefore, it was confirmed that the antifungal coat was excellent in antifungal performance and had an excellent effect of inhibiting the growth of fungus.

From the above results, according to the method for evaluating the antifungal performance according to Example 1 of the present invention, data with excellent reproducibility can be obtained very easily, and in a short time of 48 to 72 hours. It was confirmed that the antifungal performance of the material to be evaluated can be evaluated.

(Test 1) A glass plate was used in place of the material to be evaluated, and thiabendazole was further added as a fungicide to the mold spore suspension medium.
The same test as in Example 1 was performed to evaluate the antifungal performance of thiabendazole, a fungicide. The details will be described below.

On a potato dextrose agar medium 28
5 spores of Aspergillus niger spores cultured at 7 ° C. for 7 days are scraped with 10 ml of 0.005% (% by mass).
Suspended in dioctyl sodium sulfosuccinate,
A mold spore suspension was obtained.

Potato dextrose agarose medium kept at 40 ° C. (agarose concentration: 0.7% by mass)
0.2 ml of the mold spore suspension was added to 50 ml and mixed to obtain a mold spore suspension medium.

After the above mold spore suspension medium was dispensed into a plurality of test tubes, thiabendazole as a fungicide was added to each test tube at a concentration of 1.2, except for one test tube.
5, 2.5, 5, 20, and 40 mg / L (liter) were added and mixed. In addition, about the said 1 test tube, the said mold spore suspension culture medium is still contained (the thiabendazole is not added).

After placing a glass plate of 3 cm × 3 cm in a Petri dish, vacuum grease is applied to one end face of a glass cylindrical ring having an inner diameter of 2 cm and a height of 1 cm, and the ring is placed on the glass plate in the Petri dish. And placed on top of it.

Next, 0.3 ml of the mold spore suspension medium (containing thiabendazole) was placed in the ring.
The mold suspension medium was shaken and spread so that the thickness (depth) of the mold spore suspension medium was constant. In addition, 0.3 ml of a mold spore suspension medium to which thiabendazole was not added was put in one ring.

Thereafter, the petri dish was immediately covered with a lid. Then, the cells were cultured at 28 ° C. for 72 hours.
Two hours later, the growth of the mold was observed, and the fungicidal performance of thiabendazole was evaluated. In this evaluation,
As the evaluation criterion, the above-described method of evaluating in six steps was adopted. That is, the following six-step evaluation method was adopted.

[Score Evaluation] 1: Spores are generated on the entire surface. 2: State between 1 and 3 below. 3: Spores are slightly observed. 4: No spores were generated, but hyphal growth was observed on almost the entire surface. 5: No spores were generated, but growth of hypha was slightly observed. 6: No generation of spores and no growth of hypha are observed.

Table 2 shows the results of the evaluation test. As can be seen from Table 2, the concentration of thiabendazole was 2.5 m
At g / L or less, mold growth was observed, and
After 2 hours, spores are generated on the entire surface, have no fungicidal effect, and when the concentration of thiabendazole is 5 mg / L, there is a slight mold growth inhibitory effect, and when the concentration of thiabendazole is 10 mg / L. Showed no generation of spores and no growth of hypha even after 72 hours of culture, and the growth of mold was completely inhibited. This indicates that the minimum concentration of thiabendazole required to inhibit mold growth is 10 mg / L.

Generally, the minimum known inhibitory concentration of thiabendazole against Aspergillus niger (the minimum concentration of thiabendazole required to inhibit the growth of mold from spores of Aspergillus niger) is 10 mg / L. is there. The minimum growth inhibitory concentration of thiabendazole obtained as a result of the evaluation test (10
mg / L) is consistent with this known value.

Therefore, according to the above test, 48 to
It was confirmed that the minimum growth inhibitory concentration of the fungicide could be accurately determined in a short time of 72 hours.

From the above results, according to the test described above, it was possible to accurately evaluate the antifungal performance of the antifungal agent in a short time of 48 to 72 hours. 48 to 72 according to the test method for evaluating antifungal performance
It was confirmed that the antifungal performance of the material to be evaluated can be accurately evaluated in a short period of time.

[0059]

[Table 1]

[0060]

[Table 2]

[0061]

According to the test method for evaluating the antifungal performance according to the present invention, it is possible to obtain excellent reproducibility and excellent reliability very easily as compared with the conventional test method for evaluating the antifungal performance. You will be able to get data. In addition, the growth rate of the mold is higher than that of the conventional method for evaluating the antifungal performance, so that the antifungal performance of the test material can be evaluated in a short time.

Claims (2)

[Claims] 1. A cylindrical member having an opening at least in a bottom portion is placed in close contact with a target material for an evaluation test of the anti-mold performance, with the bottom portion facing down, and a mold spore suspension is provided inside the cylindrical member. A test method for evaluating the antifungal performance, wherein a liquid material containing a liquid is put in, and then cultured to evaluate the antifungal performance of the target material for the evaluation test according to the growth state of the fungus. 2. The method according to claim 1, wherein the liquid material contains a culture medium.