JPS6084203A - Antimicrobial agent - Google Patents

Abstract

PURPOSE:An antimicrobial agent, containing an isothiazolone based compound and a bromonitroalcohol based compound together, and capable of preventing sufficiently slime trouble in water systems, e.g. cooling water, paper and pulp water systems. CONSTITUTION:An antimicrobial agent containing an isothiazolone based compound of formula I (X is halogen; Y is H or X and Y form benzene ring; R is alkyl) such as 5-chloro-2-methyl-4-isothiazolin-3-one or 1,2-benzisothiazolin-3-one and a bromonitroalcohol based compound of formula II (R and R' are 1-5C alkyl) such as 2-bromo-2-nitropropane-1,3-diol,3-bromo-2-nitropropane-1,3-diol or 3-bromo-3-nitropenten-2,4-diol, preferably at (4:1)-(1:1) ratio in combination.

Description

[Detailed description of the invention] The present invention relates to a water-based antibacterial agent.

In cooling water systems, slime damage is often caused by zooglai bacteria, algae, filamentous fungi, etc. As a result, this not only causes a decrease in thermal efficiency and worsens water flow, but also causes local corrosion of equipment, piping, etc. In addition, in paper/pulp/water systems, slime damage caused by bacteria, filamentous fungi, and yeast is mainly caused during the paper-making process. When slime is mixed in as a foreign substance in pipe slurry, it not only reduces the overall quality of the product, but also causes paper breakage and disturbs the continuous operation of the paper machine, greatly reducing production efficiency. To completely prevent slime bacteria as described above, it is necessary to destroy or inhibit their growth. For this reason, inthiazolone compounds or bromonitroalcohol compounds have been proposed separately as p-antibacterial agents.

However, these antibacterial agents were not always able to completely prevent slime damage. In particular, it is known that when intiazolone compounds are used over a long period of time, slime-constituting bacteria tend to develop resistance, and resistant bacteria tend to take priority. Furthermore, in recent years, there has been a demand for highly effective antibacterial agents in order to reduce processing costs.

An object of the present invention is to provide an antibacterial agent that is highly effective enough to sufficiently prevent slime damage in water systems such as cooling water systems and paper/pulp water systems.

The present inventors have discovered that the above antibacterial agents are more effective when used in combination than when used alone. That is, the present invention is an antibacterial agent containing an isoteazolone compound and a bromonitroalcohol compound.

The intiazolone compound has the general formula (X represents H or a halogen atom, Y represents Ht, and X and Y can also be represented as benzene 14. Ri'l: represents an alkyl group having 1 to 5 carbon atoms.) It is a compound that can be expressed as A typical example of this is 5-chloro-2-methyl-4-inthiabulin-3
-one, 112-one, 112-one, dithiazolin-3-one, etc.

The bromonitroalcohol compound is a compound that can be represented by the general formula % (R and R' represent an alkyl group having 1 to 5 carbon atoms). Representative examples include 2-bromo-2-nitropropane-1,3-diol and 3-zolomo-3-nitropentene-2,4-diol.

The mixing ratio of the intiazolone compound and the bromonitroalcohol compound is not particularly limited, but is 4:1 to 1:1:
Particularly high efficacy is exhibited in the range of l. Further, in the method of use of the present invention, it is sufficient to add them to the water system in the same manner as in the past, and both may be mixed in advance at a predetermined concentration or may be added to the system separately. The concentration added varies depending on the water system, etc., but is usually 0.
．． It is good if it is about 5-500-/l.

According to the present invention, an excellent synergistic effect, which has not been known in the past, can be obtained by using an intiazolone compound and a bromonitroalcohol compound in combination. That is, the slime control effect is improved when used alone, the antibacterial spectrum is broader than when used alone9, and resistance is less likely to develop, allowing long-term use.

In addition, when an open compound is used in combination, it does not become unstable or cause a chemical reaction.

Moreover, the toxicity to the human body does not become high.

Example 1 The results of determining the minimum growth inhibitory concentration (MIC24) using Escherichia coli are shown in the figure. The test conditions were peptone-yeast extract gold-based liquid medium of pn 7 (peptone 1 g
/II, containing yeast extract 19711) to 1.0'
The cells were inoculated at f@/rnl and cultured with shaking at 35C for 24 hours. The inthazolone compound used here was 5-chloro-2-methyl-4-inthiazoline-3-
On (A) is 10% pure theol. On bromonitroalcohol M compound, 2-7” bromo 2-nitroprono
-1,3-diol ■) with a purity of 98%. The results are shown as the average value of two measurements.

From the results shown in the figure, it can be seen that a particularly high synergistic effect is exhibited when A:B is in the range of 4:1 to 1:1.

Example 2 Next m11/7″IMr-θ) Published) Take 2 φ, Mu 4 Release 1
At the warehouse, 1,2-benzisothiazolin-3-one (C) with a purity of 10% and 3-bromo-3 with a purity of 98%.
-Nitropentene-2,4-diol (D) The results of a complete comparison of the antibacterial activity when each was used alone and when C and Di were used in combination are shown in Table 1. The test conditions are the same as in Example 1. The results shown in Table 1 show that the antibacterial spectrum was broadened.

Table 1 a: Bacteria isolated from paperboard making system b = Gap 1' from cardboard waste paper system c: Bacteria isolated from toilet paper making yarn Example 3 5-chloro-2-methyl-4-inteazoline- 3-one (4) and 2-bromo-2-nitropropane-1,3-
A mixture of diol (B) and diol (B) in a total ratio of 1:1 was continuously added for one month using model cooling water Zorant so that the amount of blow water was 5 m9/l. The results are shown in Table 2. In addition, the MIC for growing bacteria in the circulating water immediately after the test and the M for growing bacteria in the circulating water after the test is completed.
The results of all IC measurements are also shown. For comparison, cases where A and B were tested individually are also shown. Table-2
As a result, it is understood that the slime control effect is improved, resistance is less likely to develop, and long-term use is possible.

Table-2

[Brief explanation of drawings]

The figure shows the synergistic effects of the combined use of the intiazolone yarn compound r#(5) and the bromonitroalcohol grand compound 'a CB).

Claims (1)

[Claims] 1. An antibacterial agent containing inthiazolone compounds, bromonitroalcohol compounds, and gold.