JPS601105A - Slime controlling method - Google Patents

Abstract

PURPOSE:To achieve strong antibacterial effect with a small amount of agent, and to economically prevent the formation of slime, by adding 4,5-dichloro-1,2- dithiol-3-one and isothiazolone at a specific ratio to a water system. CONSTITUTION:(A) 4,5-Dichloro-1,2-dithiol-3-one and (B) an isothiazolone compound of formula (X is H or Cl; M is alkali metal or alkaline earth metal; Y is anionic atom of group which forms together with the cation M a compound having sufficiently high solubility to form a complex; m is 1 or 2; n is a number corresponding to the valences of the anion Y and the cation M) are added to a water system at a weight ratio of 95:5-5:95, preferably 20:80-60:40. The concentration of the mixture in the system is about 0.05-100ppm, and in the case of the process water or cooling water system of paper industry or chemical industry, it is preferably about 0.5-50ppm.

Description

[Detailed description of the invention] This invention relates to a slime control method.

More specifically, 5-dichloro-1,2-diteo-
/I/-3-one and general formula (1); ← However, in the formula, X represents a hydrogen atom or a chlorine atom, M represents a 7μ potash metal or a 7μ potash earth metal atom, and Y represents a complex compound. Indicates an anionic atom or group that forms a compound with the cation M that has sufficient solubility to form. Further, m represents an integer of 1t or 2, and n represents the number by which the anion Y mixes the valence of the cation M. ) is added to an aqueous system such that the ratio of the former to the latter is 95=5 to 5:95 by weight.

The slime control method consisting of adding the above two types of ingredients of Kibatsu tJJ maintains the antibacterial spectrum of each ingredient, while providing a strong synergistic effect of antibacterial action.

In recent years, problems caused by slime in various types of industrial water due to microbial contamination have frequently occurred, resulting in various adverse effects. For example, slime is generated in heat exchangers and piping of circulating cooling systems used in petrochemical factories or chemical factories, clogging the pipes and reducing cooling efficiency, or white water in the paper industry. Slime is generated inside,
This may have a negative impact on the finished product itself, greatly reducing its value as a product. To explain in detail the tong μ in the paper manufacturing process, microorganisms generated in the white water system during the paper manufacturing process form a muddy slime, which peels off and mixes with the paper. The paper is cut and has spots on it, which significantly reduces the quality of the product. In addition, when slime is generated in industrial raw water, an unpleasant odor is generated and the product is colored, which similarly reduces the commercial value.

Dichloro-1,2-dithio-/I/-s-one is an excellent thiol-3-one, and by adding one or more of the intiazolones as a second component, the bactericidal action is stronger than that of the single one. In other words, what fraction of the drug effect when used alone
The present inventors have discovered a practically remarkable synergistic effect in which the same effect can be achieved with a smaller amount, and have completed the present invention.

The 3-inchazolones of Himi 9j include the following:

2-Methylv-3-inchazolone 5-chloro-2-methy/L/-3-isothiazolone Metal salts that form complex salts with the above-mentioned 3-isothiazolones include the following.

Calcium chloride salt, zinc chloride, iron chloride, magnesium chloride, magnesium nitrate, which are easily available
It is suitable to use magnesium chloride or magnesium nitrate salts.

4.5-dichloro-1,2-dithio-A/-3-one and the above isothiazolones in a weight ratio of 5=95 to 95:5 (
Preferably, when the ratio is 20:80 to 80:20, a strong synergistic effect is shown when the ratio is preferably 20:80 to 60:40. ) to the aqueous system at a ratio of
It has become clear that the growth of bacteria can be significantly inhibited by using a pre-mixed mixed drug at a concentration of several ppm. In addition, by using them in combination, it is possible to significantly reduce the amount of drugs and drugs used, and the cost is reduced accordingly, which is a great practical advantage.

In actual use, each of Kiba IJJ's streak control agent components is added to the water system independently, or 4,5-dichloroμm1.2-dithio-A/-3- Dissolve ion in a hydrophilic organic solvent (ethylene glycol, methyl cellosolve, etc.), add a surfactant to it and homogenize it, then add the second component, an aqueous solution of a water-soluble ftN salt of isothiazolones, and homogenize it. It can be formulated by

By adding this formulation to an aqueous system at a synergistic concentration, slime formation can be prevented.

The amount added (total) depends on the different target systems and is not particularly limited from that point of view, but if the concentration in the system is usually 0.015 ppm, even if the most preferable ratio is used. The synergistic bactericidal and static effects produced are insufficient for practical purposes, and even if added to overbite at 100 ppm or more, there is no particular advantage in terms of effectiveness compared to when it is less than 100 ppm. It is disadvantageous in terms of reputation. And for example,
Approximately 0.5 to 50 ppm is suitable for process water and cooling water systems in the paper industry and chemical industry. However, in cases where microorganisms are abnormally occurring, it is appropriate to add as high a concentration as possible17), and it may be necessary to add an excess of 100 ppm.

Next, a synergistic effect test example of two components used to complete the present invention will be explained.

[Formulation test example]

4.5-dichloro-1,2-dithio-A/-3-one 3
The heavy part is diethylene glycol ~ monomethylene ether/l/
12, add 5.3 parts by weight of diethylene glycol-μ and 0.2 parts by weight of Tetronic 702 (trade name, manufactured by Asahi Denka Kogyo Co., Ltd.) and mix well. To this was added 366% of a 3:1 mixture of magnesium chloride and magnesium nitrate of 5-chloro-2-methy/L/-3-isothiazolone and 2-methyl-3-isothiazolone.
Add 9.5 parts by weight of an aqueous solution containing cents and mix well to obtain a liquid preparation.

[Example of synergistic effect test]

Synergy between two components is determined by the binary dilution method.

Both components are diluted to a predetermined concentration, and a fixed amount of each is added to Puimin medium. Next, a certain amount of the pre-cultured bacterial solution was inoculated, and after culturing with shaking at 37°C for 8 hours,
The concentration of both components at which no increase in absorbance was observed at 6750 nm was determined by the binary dilution method using the minimum inhibitory concentration (hereinafter referred to as TDM).
It is called IC. ).

Figure 1 is a graph in which the minimum inhibitory concentration of each component is plotted equally on both axes using normal scale coordinates. , the lower area shows the proliferation zone. Further, when the TDM C curve and the diagonal line match, it indicates an additive effect, when the curve is above the diagonal line, it indicates an antagonistic effect, and when it is below the diagonal line, it indicates a synergistic effect.

Next, the effects of the drug of the present invention on various microorganisms isolated from collected slime from a system actually causing slime trap μ will be explained in Examples.

Example 1 (1) Microorganisms to be tested Pink slime generated in a high-quality paper machine at a certain paper mill was collected, and microorganisms were separated using Waxman's medium.

Among them, microorganisms with red colonies were isolated and used in the following experiment. When the isolated microorganism was identified, it was estimated to belong to the genus 72pobacterium.

(2) Test method 4. 5-dichloro-1,2-dithio-/L/-3-one (hereinafter referred to as compound A) was diluted to 0.4 μg/-, and 3-isothiazolone As a class, 5
-chloro-2-methy/L/-3-isothiazolone and 2
- A 3=1 mixture of magnesium chloride and magnesium nitrate lead salt (hereinafter referred to as compound B) of methyl-3-inteazolone was diluted to 3.5 μg/mJ. Thereafter, the synergistic effect was examined according to the above [Example of Synergistic Effect Test].

(3) Test results As shown in Figure 2, 7 isolated from pink slime
The TDM curve against Rabobacterium microorganisms clearly indicates a synergistic effect.For example, the synergistic effect of two components that completely suppressed the growth of the bacteria is shown at a concentration of Compound A of 1 μg/ysl. and the concentration of compound B is 0.22
It appeared when μglIll.

Compound A alone inhibits the growth of each at a concentration of 0.4 μg/ml, and Compound B alone inhibits the growth of each at a concentration of 3.5 μg/ml.
It was also shown that Compound B, when used alone, had a considerably strong synergistic effect when the amount was about 6. Other combinations of concentrations of compounds A and B that produce a synergistic effect are as shown in Table 1, for example.

Table 1 Example 2 (1) Test microorganisms Slime generated in a cooling tower of a certain chemical factory was collected, and microorganisms were separated using a standard medium.

The isolated microorganisms were subjected to the following experiments. When the isolated microorganism was identified, it was estimated to be of the genus Pseudomonas.

(2) Test method As in Example 1, the synergistic effect of compounds A and B was investigated, and as a result, a clear synergistic effect as shown in FIG. 3 appeared.

(3) Test results The slime control μ agent of the present invention contains, for example, compound A
The concentration of compound B is 0.31 μg/d, and the concentration of compound B is 0.4
A synergistic effect was shown at 6 μg/sl.

Since the minimum inhibitory concentration of Compound A alone is 1.25 μg/d and that of Compound B alone is 1.84 μg/me, the drug of the present invention has a minimum inhibitory concentration of approximately 4 μg/d when Compound A alone is used, and a It shows the same effect in terms of the terms.

Other concentration combinations of compounds A and B that exhibit synergistic effects are as shown in Table 2.

Table 2 Example 3 (1) Test microorganisms Bacteria were isolated from slime generated during the papermaking process at a certain paper mill. When the isolated microorganism was identified, it was presumed to belong to the genus Bacillus.

(2) Test Method As a result of examining the synergistic effect of Compounds A and B in the same manner as in Example 1, a clear synergistic effect as shown in FIG. 4 was found.

(3) Test results The slime control μ agent of the present invention, for example,
O concentration is 0.04 μg/at and compound Bo concentration is 0.2
A synergistic effect was shown at 3 μg/d. 0.3 μg/d for compound A alone, 1.84 μg for compound B alone
Since the minimum inhibitory concentration is /R1, the drug of the present invention exhibits the same efficacy when using Compound A alone and when using Compound B alone.

Other concentration combinations of compounds A and B that exhibit synergistic effects are, for example, as shown in Table 3.

Table 3 □ Example 4 At the paper mill described in Example 3, a feed μ feed test was actually conducted. The drug mixing ratio is Compound A: Compound B = 6
Using 0:40, the drug addition concentration was 1.5 p.
pm for 2 hours, and the mixture was returned to the algae three times a day.

As a result, the occurrence of slime that had been causing problems by adhering to the walls of head boxes and white water pits in the U.S. was drastically reduced, allowing operations to continue without any problems, and its value as a slime control agent has been fully demonstrated. It was something to do.

According to the results of Examples 1 to 3, the range in which a particularly preferable synergistic effect is exhibited is when 4,5-dichloro1.2-dite-A/-3-one and isothiazolones are mixed in a ratio of 20:8.
It was also found that this is the case when used at a ratio of 0 to 60:40.

[Brief explanation of drawings]

FIG. 1 is a diagram 57 illustrating the minimum inhibitory concentration curve by the two-way dilution method, and the second to fourth factors are the minimum inhibitory concentration curves for slime isolates by the two-way dilution method of the slime control μ agent of the present invention. The horizontal axes in Figures 2 to 4 are graphs showing inhibition concentration curves.
Minimum inhibitory concentration of dithio-/l/-3-one (MCC
, μg/R1) on the vertical axis, the minimum inhibitory concentration of 3-inteazolone (uTT! - n17 /mal 1 m A - h 1 S hy w hand - 3 v! J Fig. 4

Claims (1)

[Scope of claims]
-one and the general formula (■): (However, in the formula, X represents a hydrogen atom or a chlorine atom, M represents an alkali metal or 7μ potassium earth metal atom, and Y represents a Indicates an anion atom or group that forms a compound with cation M that has solubility. It also indicates malt or an integer of 2, and n indicates the number by which anion Y displaces the valence of cation M.) The ratio of inteazolone and t1 expressed by the former to the latter is 95:
5 to 5:95 t% to be added to the aqueous system. (2) 4t 5-dichloro-1,2-dithio-A/-
3-one, intiazolone represented by general formula (1), and the total concentration of both in the gold aqueous system from 0.05 to 100 pp.
The slime control method according to claim 1, which comprises adding m.