JPH0375522B2 - - Google Patents

Description

[Detailed description of the invention]

This invention relates to a slime control method. More specifically, 4,5-dichloro-1,2
-dithiol-3-one and general formula (): (However, in the formula, isothiazolone represented by an integer, n indicates the number of anions Y that satisfies the valence of the cations M. The present invention relates to a slime control method characterized by adding to the slime. The slime control method of the present invention, which involves adding the above two types of components, maintains the antibacterial spectrum of each component while providing a stronger 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 and chemical factories, etc., clogging the pipes and reducing cooling efficiency. Slime is generated in the product, which has a negative impact on the finished product itself, and greatly reduces the value of the product as a product. To explain this problem in the paper industry in detail, microorganisms generated in the white water system during the paper manufacturing process form a muddy slime, which peels off and mixes with the paper, causing the paper to be cut during the winding process. This causes stains on the paper, 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. It is known that the following 4,5-dichloro-1,2-dithiol-3-one has an excellent effect as a slime control agent for industrial water such as cooling water, washing water, and raw water. (Special Publication No. 52-14294). The present inventors obtained the above 4,5-dichloro-1,2
- By adding one or more isothiazolones as a second component to dithiol-3-one, the bactericidal action is stronger than that of the single one, in other words, the amount of the drug is a fraction of the amount when used alone. The present inventors discovered a synergistic effect that is practically remarkable, and achieved the present invention by producing similar effects in different amounts. The 3-isothiazolones of the present invention refer to 5-chloro-2-methyl-3-isothiazolones. Further, the metal salts that form complex salts with the above-mentioned 3-isothiazolones include the following. Calcium chloride, zinc chloride, iron chloride, magnesium chloride, magnesium nitrate Among these, it is appropriate to use calcium chloride salt, magnesium chloride salt, or magnesium nitrate salt because they are easily available. Such 5-chloro-2-methyl-3-isothiazolones can be commercially available products, such as 2-methyl-
Those available as a mixture with 3-isothiazolone can also be used as they are. 4,5-dichloro-1,2-dithiol-3-
and the above-mentioned isothiazolones in a weight ratio of 5:95 to
95:5 (preferably from 20:30 to 80:20, particularly preferably from 20:80 to 60:40 exhibits a strong synergistic effect) or premixed mixture. It has become clear that bacterial growth can be significantly inhibited when the drug is used at a concentration of several ppm.
Moreover, by using them in combination, it is possible to drastically reduce the amount of drugs required, and the cost is reduced accordingly, which is a great practical advantage. In actual use, each of the slime control agent components of the present invention is added to an aqueous system independently, or 4,5-dichloro-1,2-dithiol-3-one is added to a hydrophilic organic solvent. (ethylene glycol, methyl cellosolve, etc.), add a surfactant to the solution, homogenize it, and then add the second component, an aqueous solution of a water-soluble complex salt of isothiazolones, to homogenize it. By adding this formulation to an aqueous system at a synergistic concentration, slime formation can be prevented. The amount added (total) depends on the target system and is not particularly limited from that point of view, but if the concentration in the system is less than 0.05 ppm, it will usually occur even when the most preferable ratio is used. The synergistic bactericidal and bacteriostatic powers of these drugs are insufficient for practical use.
Further, even if the amount is added in excess of 100 ppm, there is no particular advantage in terms of effectiveness compared to the case where the amount is less than 100 ppm, and this is disadvantageous in terms of economy. For example, in process water and cooling water systems in the paper industry and chemical industry, 0.5~
Approximately 50 ppm is suitable. However, in cases where microorganisms are abnormally occurring, it is appropriate to add to the highest possible concentration, and it may be necessary to add more than 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-dithiol-3-
Dissolve 3 parts by weight of 3 parts by weight of diethylene glycol monomethyl ether in 12 parts by weight of diethylene glycol monomethyl ether, add 75.3 parts by weight of diethylene glycol and 0.2 parts by weight of Tetronik 702 (trade name, manufactured by Asahi Denka Kogyo Co., Ltd.), and mix well. To this, 5-chloro-2methyl-3-
Add 9.5 parts by weight of an aqueous solution containing 36% by weight of magnesium chloride complex salt of isothiazolone and mix thoroughly to obtain a liquid preparation. [Example of synergistic effect test] The synergistic effect between two components is measured by the binary 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, and after culturing with shaking at 37°C for 8 hours, the concentration of both components at which no increase in absorbance at 660 nm was observed was determined by the binary dilution method to the minimum inhibitory concentration. (hereinafter referred to as TDMIC).
FIG. 1 is a graph in which the minimum inhibitory concentration of each component is plotted equally on both axes using normal scale coordinates. The curve of this graph i.e. TDMIC
The area above the curve indicates the growth inhibition zone and the area below the growth zone. Further, when the TDMIC 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, slime was collected from a system actually causing slime trouble, and the effect of the agent of the present invention on various microorganisms isolated from the slime will be explained using Examples. Example 1 (1) Test microorganisms Pink slime generated in a high-quality paper machine at a certain paper mill was collected, and microorganisms were separated using Waxmann'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 Flavobacterium. (2) Test method 4,5-dichloro-1,2-dithiol-3-
(hereinafter referred to as compound A) was diluted multiple times from 0.4 μg/ml, and the 3-isothiazolones were 5-chloro-2-methyl-3-isothiazolone and 2-methyl-3-isothiazolone. :1 mixture of magnesium chloride and magnesium nitrate complex salt (hereinafter referred to as compound B) at 3.5μ
A solution diluted several times more than g/ml was used. after that,
The synergistic effect was investigated according to the above [Example of synergistic effect test]. (3) Test results As shown in Figure 2, the effect on Flavobacterium microorganisms isolated from pink slime
The TDMIC curve clearly means a synergistic effect, and the synergistic effect of two components that completely suppressed bacterial growth is, for example, when the concentration of compound A is 0.1 μg/ml and the concentration of compound B is 0.22 μg/ml. appeared in the case. Compound A alone inhibits the growth of each compound at a concentration of 0.4 μg/ml, and compound B alone inhibits growth at a concentration of 3.5 μg/ml. The amount was about 1/16 of that when used alone, indicating that it has a fairly strong synergistic effect. Other combinations of concentrations of compounds A and B that produce a synergistic effect include, for example, the first
As shown in the table.

[Table] 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 appeared as shown in FIG. (3) Test results The slime control agent of the present invention showed a synergistic effect, for example, when the concentration of Compound A was 0.31 μg/ml and the concentration of Compound B was 0.46 μg/ml.
The minimum inhibitory concentration is 1.25 μg/ml for compound A alone and 1.84 μg/ml for compound B alone, so
The amount of the drug of the present invention is about 1/4 of that when using Compound A alone.
In addition, it shows the same efficacy at about 1/4 the amount of Compound B when used alone. Other concentration combinations of compounds A and B that exhibit synergistic effects are shown in Table 2, for example.

[Table] 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 appeared as shown in FIG. (3) Test results The slime control agent of the present invention showed a synergistic effect, for example, when the concentration of Compound A was 0.04 μg/ml and the concentration of Compound B was 0.23 μg/ml.
0.3 μg/ml for compound A alone, and 0.3 μg/ml for compound B alone.
Since the minimum inhibitory concentration is 1.84 μg/ml, the drug of the present invention exhibits the same efficacy at approximately 1/8th the amount of Compound A alone and at approximately 1/8th the amount of Compound B alone. Other concentration combinations of compounds A and B that exhibit synergistic effects are shown in Table 3, for example.

[Table] Example 4 At the paper mill described in Example 3, a field test was actually conducted. The drug mixing ratio was Compound A: Compound B = 60:40, and the drug was added for 2 hours so that the drug concentration was 1.5 ppm, and this was repeated three times a day. As a result, the generation of slime, which previously caused problems by adhering to the walls of head boxes and white water pits, has been drastically reduced, making it possible to operate without any problems, fully demonstrating its value as a slime control agent. Ta. In addition, from the results of Examples 1 to 3, the range in which a particularly preferable synergistic effect is exhibited is 4,5-dichloro-
It was also found that this is the case when 1,2-dithiol-3-one and isothiazolones are used in a ratio of 20:80 to 60:40. Example 4 (1) Test microorganisms Pink slime generated in a high-quality paper machine of a certain paper mill was collected, and microorganisms were separated using Waxmann's medium. Among them, microorganisms with red colonies were isolated and used in the following experiment. In addition,
When the isolated microorganism was identified, it was presumed to belong to the genus Flavobacterium. (2) Test method 4,5-dichloro-1,2-dithiol-3-
(hereinafter referred to as compound A) was diluted multiple times from 0.5 μg/ml, and as the 3-isothiazolones, magnesium chloride complex salt of 5-chloro-2-methyl-3-isothiazolone (hereinafter referred to as compound C) was used. 3.0 μg/ml was used. Thereafter, the synergistic effect was examined according to the above [Example of Synergistic Effect Test]. (3) Test results As shown in Figure 5, the effect on Flavobacterium microorganisms isolated from pink slime
The TDMIC curve clearly means a synergistic effect, and the synergistic effect of two components that completely suppressed bacterial growth is, for example, when the concentration of compound A is 0.13 μg/ml and the concentration of compound C is 0.19 μg/ml. appeared in the case. Compound A alone inhibits the growth of each at a concentration of 0.5 μg/ml, and Compound C alone inhibits the growth of each at a concentration of 3.0 μg/ml. The amount was about 1/16 of that when used alone, indicating that it has a fairly strong synergistic effect. In addition, compound A that exhibits a synergistic effect,
Examples of combinations of C concentrations are shown in Table 4.

[Table] Example 5 (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 4, the synergistic effect of Compounds A and C was investigated, and as shown in FIG. 6, a clear synergistic effect appeared. (3) Test results The slime control agent of the present invention showed a synergistic effect, for example, when the concentration of Compound A was 0.13 μg/ml and the concentration of Compound C was 0.25 μg/ml.
1.0 μg/ml for compound A alone, and 1.0 μg/ml for compound C alone.
Since the minimum inhibitory concentration is 2.0 μg/ml, the drug of the present invention exhibits the same efficacy at approximately 1/8th the amount of Compound A alone and at approximately 1/8th the amount of Compound C alone. Other concentration combinations of Compounds A and C that exhibit synergistic effects are shown in Table 5, for example.

[Table] Example 6 (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 C in the same manner as in Example 4, a clear synergistic effect appeared as shown in FIG. (3) Test results The slime control agent of the present invention showed a synergistic effect, for example, when the concentration of Compound A was 0.19 μg/ml and the concentration of Compound C was 0.19 μg/ml.
The minimum inhibitory concentration for Compound A alone is 0.75 μg/ml, and for Compound C alone, the minimum inhibitory concentration is 1.5 μg/ml. Approximately 1/8th the amount shows the same efficacy. Other concentration combinations of Compounds A and C that exhibit synergistic effects are shown in Table 6, for example.

[Test 1]

4,5-dichloro-1,2-dithiol-3-
The synergistic effect of On and 3-isothiazolone,
Comparative test on the synergistic effect of 4,5-dichloro-1,2-dithiol-3-one and 1,2-benzisothiazolin-3-one (1) Test method White water collected from two certain factories and one from a certain factory Dispense the collected slime into a 10 ml L-shaped tube (however, the slime was disintegrated with a mixer and diluted and dispersed with sterilized water to a ratio of 3/100), and the test drug was added at a concentration of 10 mg/1, and each temperature condition was Incubate with shaking for 60 minutes at
Afterwards, the number of bacteria was measured. (2) Collection location and properties of sample white water and slime (a): White water collected from a newsprint machine at a certain paper factory, pH 5.8, temperature 38°C, isolated bacteria Pseudomonas sp., Batillus sp. (b): Certain White water collected from a coated base paper machine at a paper mill, pH 7.2, temperature 35°C, SO ₃ ^2-3.5 mg/l, isolated bacteria Pseudomonas sp., Alcaligenes sp. (c): Save all from a printing paper machine at a certain paper mill Slime temperature 27℃, isolated bacteria Penicillium sp. Aspergillus sp. (3) Test agent (i) Combination according to the present invention 4,5-dichloro-1,2-dithiol-
3-one (compound A) and 5-chloro-2-methyl-3-isothiazolone and 2-methyl-3
- A 3:1 mixture of isothiazolone magnesium chloride and magnesium nitrate complex (compound B) is blended in various proportions with 10 parts by weight of this blend, 89.8 parts by weight of diethylene glycol monomethyl ether (solvent) and Tetronic.
^R 702 (nonionic surfactant; manufactured by Asahi Denka Kogyo Co., Ltd.)
Concomitant drug prepared by mixing 0.2 parts by weight. (ii) Combination according to JP-A-57-167901 4,5-dichloro-1,2-dithiol-
3-one (Compound A) and 1,2-benzisothiazolin-3-one (Compound D) were blended in various proportions, and 10 parts by weight of this blend and diethylene glycol monomethyl ether (solvent) were added.
A combination drug prepared by mixing 89.8 parts by weight and 0.2 parts by weight of Tetronik ^R 702 (nonionic surfactant; manufactured by Asahi Denka Kogyo Co., Ltd.).

【table】

〔test 〕

4,5-dichloro-1,2-dithiol-3-
formulations with 1 and 3-isothiazolone and 4,5-
dichloro-1,2-dithiol-3-one and 1,
Property comparison test with 2-benzisothiazolin-3-one formulation (1) Test method Each test drug was left in a constant temperature bath at 37℃ for 30 days.
The decomposition rate of 4,5-dichloro-1,2-dithiol-3-one was measured by HPLC to evaluate stability. (2) Test drug (i) Combination 4,5-dichloro-1,2-dithiol-3- according to the present invention
on (compound A) 5 parts by weight, 5-chloro-2-
Methyl-3-isothiazolone and 2-methyl-3
- Magnesium chloride and magnesium nitrate complex of a 3:1 mixture of isothiazolones (compound B)
5 parts by weight, diethylene glycol monomethyl ether (solvent) 89.8 parts by weight, and Tetronik ^R
702 (nonionic surfactant; manufactured by Asahi Denka Kogyo Co., Ltd.)
Concomitant drug prepared by mixing 0.2 parts by weight. (ii) Combination according to JP-A-57-167901 Prepared in the same manner as above except that 1,2benziisothiazolone-3-one (compound D) was used instead of compound B in the concomitant drug of (i) above. Concomitant drugs. (3) Test results

[Table] (4) Discussion From these results, it is recognized that the combination drug of Compound A and Compound B has significantly higher formulation stability than the combination drug of Compound A and Compound D.

[Brief explanation of drawings]

FIG. 1 is a graph illustrating the minimum inhibitory concentration curve obtained by the two-way dilution method, and FIGS. 2 to 7 are graphs showing the minimum inhibitory concentration curve of the slime control agent of the present invention against slime isolates obtained by the two-way dilution method, respectively. This is a graph showing a curve, and the horizontal axis of FIGS. 2 to 7 is 4,5-dichloro-1,2-dithiol-
Minimum inhibitory concentration (MIC, μg/ml) of 3-one
The vertical axis shows the minimum inhibitory concentration (MIC, μg/ml) of 3-isothiazolones. 8th
-FIG. 10 are graphs showing differences in synergistic effects with comparative drugs.

Claims (1)

[Claims] 1 4,5-dichloro-1,2-dithiol-3
−on and the general formula (): (However, in the formula, X represents a chlorine atom, M represents an alkali metal or alkaline earth metal atom, and Y represents an anion that forms a compound with the cation M that has sufficient solubility to form a complex compound.) represents an atom or group; m represents an integer of 1 or 2;
n indicates the number by which the anion Y satisfies the valence of the cation M. ) is added to an aqueous system such that the ratio of the former to the subject is 60:40 to 20:80 by weight. 2 4,5-dichloro-1,2-dithiol-3
-one and isothiazolone represented by the general formula () in an aqueous system at a total concentration of 0.05~
The slime control method according to claim 1, which comprises adding 100 ppm.