JPH06245794A - Method for testing antifungal performance - Google Patents

Abstract

PURPOSE:To provide a simple and practical method capable of properly assessing the antifungal performance of antifungal agent-contg. sealants to be used in kitchens, bathrooms, washrooms toilets, etc. CONSTITUTION:A test piece of antifungal agent-contg. silicone sealant is put to degenerative treatment for the antifungal agent followed by bactericidal treatment, and the resultant test piece is coated with an nutrient containing 250wt.% of a 10-18C fatty acid sodium salt and dried, and a test bacteria solution is then applied on the test piece followed by conducting a culture, and the antifungal performance of the sealant is assessed based on the growing situation of the test bacteria.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a test method for antifungal performance of a silicone sealant containing an antifungal agent used in bathrooms and other areas around water, and more particularly, to a simple and easy method for developing silicone sealants. It relates to a practical antifungal performance test method.

[0002]

2. Description of the Related Art Conventionally, there is no practical test method of antifungal performance for a silicone sealant containing an antifungal agent used around water such as a bathroom. Therefore, JIS Z2
The general antifungal resistance test method defined in 911 is combined to evaluate the antifungal performance of the antifungal agent-containing sealant.

However, since the silicone sealant itself does not serve as a nutrient source for microorganisms, it is difficult to grow mold on the test piece, and the obtained test results have large variations.

There is a fungus resistance test in JIS Z2911, but this test method is not related to the test method for antifungal performance of a silicone sealant containing an antifungal agent, and the test bacteria specified in this test method are: Since it is a strain collected from various places and is not a strain that causes a problem especially in the water area, there is a problem that it is not suitable for evaluation of materials used in the water area such as a silicone sealant.

[0005] Recently, as a new practical antifungal test method for paints, a preliminary test was carried out with a strain consisting mainly of the evaluation target bacteria used in JIS Z2911, and a test sample for which the antifungal effect could be confirmed was subjected to Altanaria. Japanese Patent Application Laid-Open No. 4-49400 discloses a method of carrying out a practical test using Alternata, Cladosporium, Sphaerospermum, and Fusarium oxysporum as evaluation target bacteria.

However, when this antifungal test method is applied to a silicone sealant containing a fungicide used around water, (1) the type of contaminating bacteria causing contamination of the silicone sealant used around water Is different,
(2) Although the paint itself is considered to be a nutrient source for contaminating bacteria, in the case of a silicone sealant, it is soap residue, human dirt, etc. adhering to the sealant. (3) Silicone sealant has high water repellency and water. Since it is easily repelled, there was a problem that when the spore suspension was sprinkled, the test sample was easily spilled and the evaluation results varied.

Therefore, in order to accurately evaluate the long-term antifungal performance of the silicone sealant containing the antifungal agent,
Using actual silicone sealant contaminating bacteria, those that adhere around water that can be ingested by those bacteria are used as nutrient sources,
Although it is necessary to evaluate with a reproducible test method, such a test method has not been established yet.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks, and an object thereof is to accurately determine the antifungal performance of a silicone sealant containing an antifungal agent used around water. It is to provide a simple and practical fungicidal performance test method that can be evaluated.

[0009]

The present invention will be described in detail below. The silicone sealant used in the present invention is not special and is widely and generally used.

The nutrient source used in the present invention comprises a component containing 50% by weight or more of fatty acid sodium salt. The fatty acid sodium salt is available as a stable composition and has good adhesion to the silicone sealant. Therefore, it is suitable as a nutrient source for polluting bacteria that propagate in the bathroom environment.

By applying a nutrient source containing 50% by weight or more of fatty acid sodium salt to a silicone sealant as a carbon source and drying it, contaminating bacteria can be surely adhered to the sealant to improve reproducibility and reliability of the test. Can be increased.

When the carbon number of the fatty acid sodium salt is small, it becomes difficult to dry on the test piece, and when it is large, it becomes difficult to apply it with a solution, and even if it becomes small or large, the growth of microorganisms deteriorates. Limited to 10-18.

If the concentration of the fatty acid sodium salt in the above nutrient source becomes thin, the growth of contaminating bacteria becomes poor, and it is difficult to apply the solution and it is difficult to dry it on the silicone sealant. Limited.

A nitrogen source may be added to the above nutrient source as a component other than the fatty acid sodium salt. The nitrogen source is not particularly limited, and examples thereof include organic compounds such as peptone and casein; and inorganic compounds such as sodium nitrate and ammonium sulfate.

The antifungal agent used in the present invention is preferably one that does not cause discoloration or deterioration of physical properties of the silicone substrate, and examples thereof include pyridine antifungal agents, benzimidazole antifungal agents, and organic arsenic antifungal agents. Examples thereof include antifungal agents. The antifungal agent content in the silicone sealant is
Generally, the range of 0.0001 to 5% by weight is preferable.

As the test piece used in the present invention, for example, a silicone sealant containing a mildew proofing agent is applied to a release paper so as to have a constant thickness, cured, and then cut into a predetermined shape and released. A stripped pattern is used. The test piece has a thickness of 1 to 5 mm and a size of 1 to 30 c.
m ² is preferred.

The above-mentioned deterioration treatment of the test piece is carried out in order to accelerate the deterioration of the performance of the antifungal agent contained in the sealant or to reduce the content of the antifungal agent. Examples of the method include treatment, ultraviolet treatment, immersion in running water, immersion in an aqueous solution, and the like. Generally, a method of immersion in warm water and an aqueous surfactant solution for a certain period of time can be used.
The conditions (time, temperature, etc.) for such deterioration treatment are appropriately determined according to the usage conditions of the silicone sealant.

The test bacteria used in the present invention include:
In particular, investigation of contaminating bacteria occurring in joint materials around water such as bathrooms,
The frequency of detection and the color tone at the time of contamination have been examined, and the frequency of detection is high.
rnaria) genus; Ulocladium genus;
Cladosporium spp .; Phom
a) Four kinds of genus bacteria were selected.

The medium used in the present invention is one that is generally used, and examples thereof include potato dextrose agar medium.

[0020]

EXAMPLES Examples of the present invention will be described below. (Example 1) 1) Preparation of test piece A silicone sealant ("Tosseal # 388" manufactured by Toshiba Silicon Co., Ltd.) was mixed with a pyridine-based fungicide ("D" manufactured by ICI).
ensil S100 ") and a benzimidazole-based fungicide (" San Isol "manufactured by San-ai Petroleum Co., Ltd.) each in an amount of 1% by weight, and coated on a release paper to have a thickness of 3 mm and cured. , The layered product obtained has a diameter of 3 cm
It was punched into a circle and the release paper was peeled off to prepare a test piece.

2) Deterioration treatment of the test piece Next, the test piece was treated with an aqueous solution of a surfactant at 30 ° C. (0.05 weight each of “Nonsar LN-1” and “Nonsar TN-1” manufactured by NOF CORPORATION). % Dissolved) and subjected to deterioration treatment. The non-sar LN-1 contains 90% by weight or more of sodium salt of fatty acid having 12 carbon atoms, and the non-sar TN-1 contains 14, 16, 18 carbon atoms.
And 20 fatty acid sodium salts of 90% by weight or more, respectively.

3) Application of a nutrient source to the test piece and drying The above-mentioned deteriorated test piece was sterilized with an aqueous solution of 70% by weight of ethanol, sterilized by moist heat in advance, and then allowed to cool to room temperature. 0.05% by weight each of "Nonsar LN-1" and "Nonsar TN-1" and DIF
"Polypeptone" (containing 0.1% by weight of CO) manufactured by CO Co., Ltd.] was placed on a test piece with a pipette in an amount of 1 ml and left at room temperature for one day at 30 ° C. to evaporate and dry the water to attach a nutrient source. It was

4) Antifungal performance test A test piece having a nutrient source adhered to it was used as a soap agar medium ("Nonsar LN-1", "Nonsar TN-") prepared on a petri dish.
1 "each containing 0.05% by weight of polypeptone, 0.1% by weight of polypeptone, and 1.5% by weight of agar refined powder manufactured by Nacalai Tesque, Inc., and then 1 ml of a spore suspension of the test bacterium prepared in advance. Was sprinkled on the test piece and the medium, and the test bacterium was cultured at 28 ° C. for 28 days.

The growth of the test bacteria was evaluated by culture according to the following criteria, and the results are shown in Table 1. The number of test pieces in each test was four. (A) No mold was found on the medium: 4 (b) A blocking circle was formed around the test piece: 3 (c) Mold was found on the whole area of the medium, but on the test piece Was not observed: 2 (d) Mold was developed on the whole medium, and the mold did not disappear even if it was wiped with 70% ethanol: 1

A spore suspension of the test bacterium was prepared as follows. First, 0.05% by weight of each of "NONSAR LN-1" and "NONSAR TN-1" was added to 99.9% by weight of clear water to dissolve it, and 10 ml of the solution was then added.
The mixture was placed in a dry-heat sterilized Erlenmeyer flask with a volume of 50 ml and heat-sterilized with heat. Next, 5 platinum loops of each of the following 4 types of test bacteria were added to the sterilized water containing a surfactant, and the Erlenmeyer flask was placed in a sterile box. As a test bacterium, a preserved bacterium was transplanted to a new tilted medium, placed in a place kept at a temperature of 25 to 28 ° C., and cultivated on a tilted surface for about 2 weeks before the test, and 5 platinum earpicks from a strain with good sporulation The taken spores were used.
Next, the Erlenmeyer flask was capped with cotton as before, taken out of the sterile box, and shaken vigorously to sufficiently disperse the spores.
The contents were rubbed with sterile gauze and the filtrate was made into a spore suspension.

(Test bacterium) a) Alternaria Steviae
(IFO 31182) b) Ulocladium botrytis
tis) (IFO 5370) c) Cladosporium herbar
um) (IFO 6374) d) Phoma citricarpa (IFO 528
7)

(Example 2) The same silicone sealant as in Example 1 was added to a pyridine fungicide ("De" manufactured by ICI).
nsil S100 ”) and an organic arsenic antifungal agent (“ Binazine ”manufactured by Nomura Office Co., Ltd.) were used in the same manner as in Example 1 except that test pieces containing 1% by weight each were used.
A fungicidal performance test was conducted, and the results are shown in Table 1.

Comparative Example 1 The same procedure as in Example 1 was carried out except that the same silicone sealant as in Example 1 was used as a test piece (however, no antifungal agent was contained).
A fungicidal performance test was conducted, and the results are shown in Table 1.

(Comparative Examples 2 to 4) A fungicidal performance test was conducted in the same manner as in Example 1 except that no nutritional source was applied onto the test piece, and the results are shown in Table 1. In addition, as the test piece, the same thing as Comparative Example 2 in Example 1, Comparative Example 3 in Example 2 and Comparative Example 4 in Comparative Example 1 was used.

(Comparative Examples 5 to 7) The same procedure as in Example 1 was carried out except that no nutrient source was applied on the test pieces and the following fungus bodies specified in JIS Z2911 were used as test bacteria. The antifungal performance test was conducted, and the results are shown in Table 1. In addition, as a test piece, Comparative Example 5 is the same as Example 1.
Comparative Example 6 was the same as Example 2, and Comparative Example 7 was the same as Comparative Example 1. (Test bacterium) e) Aspergillus Niger (IFO 6
341) f) Penisillium citrinum
(IFO 6352) g) Cladospo
rium cladosporioides) (IFO 6348) h) Chaetomium globosum (IF
O 6347)

[0031]

[Table 1]

Reference Examples 1 to 3 In an actual bathroom, a silicone sealant containing a fungicide was monitored by the following method. As shown in FIG. 1, four square ceramic tiles 2 each having a side of 8 cm were attached to an acrylic resin wall panel 1 at intervals of 5 mm, and the gap and the circumference of each tile 2 were sealed with the silicone sealant 3 and tested. A panel for use was prepared. After the test panel thus prepared was placed in a bathroom washing room for 3 months and 6 months, the mold generation state of the silicone sealant 3 was visually observed.
The results are shown in Table 2. As the silicone sealant containing the antifungal agent, the same reference example 1 was used as Example 1, reference example 2 was used as Example 2 and reference example 3 was used as Comparative Example 1, respectively.

[0033]

[Table 2]

As is apparent from Table 1, Examples 1 and 2
Clearly showed the time when the efficacy of the fungicide disappeared without variation. On the other hand, when the nutrient sources of Comparative Examples 2 to 4 are not applied and when the bacterial cells defined by JIS Z2911 of Comparative Examples 5 to 7 are used, it is found that the evaluation results vary widely.

[0035]

INDUSTRIAL APPLICABILITY In the method for testing antifungal performance of the present invention, since the antifungal performance is tested by using the contaminating bacteria that actually grow around water in the house, the antifungal agent of the silicone sealant containing the antifungal agent is tested. Provide a simple and practical test method that enables accurate determination of performance. Further, the antifungal performance test method of the present invention,
Since the fungicidal performance is tested after the accelerated deterioration treatment of the fungicide contained in the silicone sealant, the long-term performance of the fungicide can be judged in a relatively short period of time.

[Brief description of drawings]

FIG. 1 is a perspective view showing a test panel used in Reference Examples 1 to 3. FIG.

[Explanation of symbols]

 1 Wall panel 2 Ceramic tile 3 Silicone sealant

Claims (1)

[Claims] 1. A test piece of a silicone sealant containing an antifungal agent is subjected to a deterioration treatment of the antifungal agent, and then the test piece is sterilized, and then the fatty acid sodium having 10 to 18 carbon atoms is applied to the test piece. A nutrient source consisting of a component containing 50% by weight or more of salt is applied in advance and dried, and then a bacterium of the genus Alternaria, Urocladium (Ul
ocladium spp., Cladosporium spp., and Phoma spp. A test fungus solution containing a test target fungus selected from the group consisting of the following bacteria is sprayed and cultured, and the fungus growth depends on the growth of the test fungus. A fungicidal performance test method characterized by judging performance.