JPS5818307A - Industrial germicide - Google Patents

Abstract

PURPOSE:An industrial germicide comprising 1,2-benzisothiazoline-3-one and benzyl-alpha-bromoacetate as active ingredients, having stronger synergistic effects for sterilization of bacteria in an aqueous organic system. CONSTITUTION:An industrial germicide comprising (A) 1,2-benzisothiazoline- 3-one and (B) benzyl-alpha-bromoacetate as active ingredients. The compound A has high suppressing effect on bacterium but low sterilizing effect on them, and low effect on a bacterium belonging to the genus Pseudomonas, a main bacterium causing the bacterial pollution of aqueous industrial materials. Its use together with the compound B is expected to have effects on almost all objects to be sterilized, smaller amounts of them exhibit similar effect than their single uses. In using the germicide, the concentration of the germicide in a weight ratio of the compound A : the compound b of (2:1)-(1:4) is sufficiently several ppm-tens ppm.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an industrial fungicide characterized by containing 1,2-benzisothiazolin-3-one and benzyl-α-bromoacetate as active ingredients.

The industrial disinfectant of the present invention comprising the two components described above provides a stronger synergistic effect of antibacterial action while retaining the antibacterial properties of each component.

Almost all aqueous organic systems are prone to attack by microorganisms, which can lead to unpleasant odors and contamination, decomposition of emulsions, coagulation of dispersions, loss of viscosity, Various adverse effects such as pH change to 0y and slime formation occur, and the value of the product as a temporary product is greatly reduced.

For example, slime can occur in heat exchangers, drainage water, and cooling pipes of circulating cooling systems used in petrochemical or chemical factories, clogging the pipes and reducing cooling efficiency, or in paper factories. Microorganisms generated in white water form a muddy slime, and when this peels off and mixes with the paper, it can cause the paper to break during the winding process, cause spots on the paper, cause unpleasant odors, and other problems. It causes trouble.

In recent years, metal-based industrial disinfectants have been avoided due to their strong disinfectant power, but also because of their harmful effects on humans and livestock, and the environmental pollution caused by contamination with wastewater, and non-metallic industrial disinfectants have been used instead. It is widely used.

1,2-benzisothiazolin-3-one, one of the active ingredients of the present invention, is widely known as an active ingredient of non-metallic, low-toxicity industrial fungicides, and is used in various applications such as the following. It is being For example, it is commonly used in the fields of emulsion paints, latex, metal processing oils such as cutting oils, water-based adhesives, preservatives such as printing pastes, coating colors for art paper gravel coated papers, or slime control agents. ing.

However, l,2-benzisothiazolin-3-one is
Although it has strong bacteriostatic power, it has weak bactericidal power, and it is also weakly effective against Pseudomonas bacteria, which is one of the main causes of microbial contamination of water-based industrial materials as mentioned above. The emergence of resistant bacteria is becoming a problem.

Therefore, the present inventors conducted extensive research on combinations of drugs that have stronger antibacterial activity than the MFL IIA compound and exhibit sustained effects. 2) It was found that the antibacterial activity was synergistically enhanced and showed a sustained effect.

In other words, the present inventors believe that by using these two components together, it can be expected to be effective against most objects to be sterilized, and that the sterilization effect is stronger than that of either agent alone. The present invention was completed by discovering an industrially significant synergistic effect that produces the same effect with a fraction of the amount.

1,2-benzisothiazolin-3-one (hereinafter referred to as compound A) and benzyl-α-bromoacetate (hereinafter referred to as compound B) are usually 8;1 to 1!128 (
weight ratio), preferably 4;l~l! 32 Particularly preferably, several ppm of a mixed drug mixed in a ratio of 2:1 to 1:4
It has become clear that when used at the concentration of the deceased ppxu, it is effective in inhibiting the growth of the dead.

Furthermore, by using the mixture in a mixed system, it is possible to greatly reduce the amount of chemicals, and the cost is reduced accordingly, which brings about a great practical advantage.

In actual use, the components of the present invention should be mixed with a hydrophilic organic solvent (
(dimethylformamide, ethylene glycol, methylcellosolve, etc.) to form a solution (in some cases, a surfactant is also added for homogenization), and then added to the system to prevent the growth of microorganisms. is possible.

Next, a method for testing the synergy of two components used to complete the present invention will be described.

Synergistic Effect Test Method The synergistic effect between two components is measured by the two-way dilution method. Both components are diluted to a predetermined concentration, and a fixed amount of each is added to the bouillon medium. Next, a certain amount of the pre-cultured bacterial solution was inoculated into the medium, and after culturing with shaking at 37°C for 6.5 hours, the concentration of both components at which no increase in absorbance was observed at 660 nm was determined by the binary dilution method. Inhibitory concentration (hereinafter referred to as 'I')
DM'I (abbreviated as !). FIG. 1 is a graph in which the minimum inhibitory concentration (hereinafter abbreviated as M-a) of each component is plotted equally on both axes using normal scale coordinates.

In this graph, the area above the curve (ie, the TDMI-C curve) indicates the growth inhibition zone, and the area below the growth zone. Further, when the diagonal line is the same as the 'I'DMC curve, it represents an additive effect, when the TDMIC curve is above the diagonal line, it represents an antagonistic effect, and when it is below the diagonal line, it represents a synergistic effect.

Next, the present invention will be explained with reference to Examples.

Example 1 Synergistic effect against Pseudomonas aeruginosa Compound B and Compound B each at 1100) t/+n
! After dilution and preparation, the synergistic effect was examined according to the test method described above.

The results are shown in FIG. This TDM engineering C curve for Pseudomonas aeruginosa clearly implies significant synergy. For example, the synergistic effect of the two treatments that completely suppressed the growth of bacteria was achieved when the concentration of compound A was 6.3.
/Ig /rne and the concentration of compound B is 3.2
) appeared when tg/lne.

In other words, this drug concentration is 1/8 of the MIC for compound A alone, and for compound B,
It was shown that this drug had a strong synergistic effect, which was 1/8 that of the drug alone. Other combinations of concentrations of compounds A and B that exhibit a synergistic effect are shown in Table 1, for example.

Table 1 and Figure 2 also show the results of combinations not listed in Table 1.

In the table, () represents a fraction of the MIC of each compound when used alone. (Hereinafter, the meaning of () in the table is the same.) In addition, M'IC in the case of compound A alone is 50) tg/
nf! and the MIC for Compound B alone is 25 g/-.

Example 2 Synergistic effect against Bacillus subtilis The results of the same test as in Example 1 are shown in Table 2 and Figure 3.

Table 2 and FIG. 3 also show the results of combinations not listed in Table 2.

In addition, the MIC in the case of compound A alone is 1.6) tg/l
nl, and the MIO in the case of compound P alone is z/m
It is l.

Example 3 Synergistic effect against Aerobacterium aerogeos.

The results of the test conducted in the same manner as in Example 1 are shown in Table 3 and FIG.

Table 3, Figure 4 also shows the results of combinations not listed in Table 3.

In addition, the MIC in the case of compound A alone was 12.5. i+g
/me, and the MIC for compound B alone is 25 g
/me.

As shown in Examples 1 to 3, the mixture of the present invention has the effect of inhibiting the growth of any of the bacteria, and exhibits the same remarkable synergistic effect even after continued shaking culture for 24 hours. Ta.

Embodiment 4 At tunnel construction sites, contamination of underground water with slime usually causes phenomena such as slowing down and clogging drains, and emitting bad odors.

The effectiveness of the mixture of the present invention was tested using slime from a drain containing the causative bacteria at a construction site for a basic tunnel.

First, the present slime-forming bacteria are precultured in a bouillon medium. Inoculate a certain amount of the activated liquid into sterile water. Thereafter, the following drugs were added at a predetermined concentration, and shake-shell culture was performed at 37°C. After shaking for a certain period of time, the raw material was measured by the plate dilution method. The results are shown in Table 4.

Table 4 Example 5 Compound A and Compound B were added to the machining section (cutting oil)! 1 of the mixture was added to 10 pp of cutting oil, and the mixture was left in a constant temperature chamber at a temperature of 30°C and a humidity of 90%.
Changes in the number of viable bacteria in the sweet potato noodles were measured over time.

Table 5 shows the results obtained by the plate dilution method.

Table 5 Live bacteria Ii1: (pcs/rn!) (Bouillon agar medium) From the above examples, l,2-benzisothiazoline-3
-one and benzyl-α-bromoacef-) in combination,
It was revealed that each compound had a remarkable synergistic effect when used alone.

[Brief explanation of the drawing]

Fig. 1 is a graph showing the minimum inhibitory concentration curve by the binary dilution method, and Figs. 2.3 and 4 are graphs showing Pseudomonas Φ aeruginosa (Fig. 2), Bacillus subtilis (Fig.
FIG. 3) is a graph showing the minimum inhibitory concentration curve of the industrial fungicide of the present invention against A. aerogenes (FIG. 3) and A. aerogenes (FIG. 4) according to the binary dilution method. Agent Patent Attorney Katsuhato Takamiyagi 1 Figure 2 Figure I L Ichi Azure B (Ab 2 Two Mushrooms 3 Figure I B, 44 Less B (2 Ini 1.) Hold 4 M f-).

Claims (1)

[Claims] 1. An industrial fungicide characterized by containing 2-benzisothiazolin-3-one and benzyl-α-bromoacetate as active ingredients.