JP5280896B2 - Microbial control agent and microorganism control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a microorganism controlling agent in which sufficient effect is acquired at addition in low concentration in an actual water system, especially in an open circulating cooling water system, safety is high, and handling is easy, and to provide a microorganism control method. <P>SOLUTION: The microorganism controlling agent includes: one or more sorts chosen from 2-phosphonobutane-1,2,4-tricarboxylic acid, 1-hydroxyethylidene-1,1-diphosphonic acid, polymaleic acid, and these water-soluble salts; and a compound shown by general formula (I), as active ingredients. In the formula, R<SB>1</SB>and R<SB>4</SB>are a 1-4C linear or branched, same or different alkylene group, R<SB>2</SB>and R<SB>5</SB>are each a hydrogen atom, a same or different halogen atom, and a lower alkyl group or a lower alkoxy group, R<SB>3</SB>is a 2-12C linear or branched alkylene group, R<SB>6</SB>is a 1-18C linear or branched alkyl group, and Z<SP>-</SP>is an anion dissociable in water. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a microbial control agent and a microbial control method for effectively controlling microorganisms in water systems such as various industrial water, waste water, cooling water, and cold / hot water.

  Among conventional microbial control agents, ordinary quaternary ammonium compounds have the disadvantage of severe foaming and are difficult to apply, particularly in cooling water systems equipped with cooling towers. In addition, although isothiazoline compounds are effective, they are toxic and irritating to the skin and are difficult to handle. Phthalaldehyde and glutaraldehyde are effective, but at low concentrations, the microorganism control properties tend to be low, and the sustainability of the control effect is low, and high concentrations need to be added.

  Here, a compound represented by the following general formula (I) has been proposed as a microorganism control agent by JP-A-2005-325036 (Patent Document 1) or JP-A-2006-21105 (Patent Document 2).

  Such compounds are known as microbial control agents that are highly safe and have no foaming properties. However, when used in actual water systems, especially in open circulation cooling water systems, a sufficient concentration of microbial control effects can be achieved at low concentrations. May not be obtained, and improvements have been demanded.

Japanese Patent Laying-Open No. 2005-325036 (Patent Document 1) JP 2006-21105 A (Patent Document 2)

  The present invention improves the above-mentioned conventional problems, that is, when added at a low concentration, a sufficient effect can be obtained in an actual water system, particularly an open circulating cooling water system, and the safety is high and the handling is easy. An object of the present invention is to provide a microorganism control agent and a microorganism control method.

  As a result of intensive studies, the present inventors have used a compound represented by the above general formula (I) in combination with a certain kind of phosphonic acid or polycarboxylic acid in which no microorganism control effect is observed. As a result, the present inventors have found that a high microorganism control effect can be obtained even in an actual aqueous system, and have reached the present invention.

That is, in order to solve the above problems, the microorganism control agent of the present invention has 2-phosphonobutane-1,2,4-tricarboxylic acid, 1-hydroxyethylidene-1,1-diphosphonic acid, and 1 or more selected from these water-soluble salts and a salt of 1,4-bis (3,3 ′-(1-decylpyridinium) methyloxy) butane in an active ingredient of 1: 5 to 50: 1 It is a microorganism control agent for sterilizing Legionella spp. In an open circulation cooling water system, characterized by containing it in a weight ratio .

The microorganism control method of the present invention, as described in claim 2 , is an aqueous system of an open circulating cooling water system having a concentration of 2 mg / L or more and 100 mg / L or less of the microorganism control agent of claim 1 as a total concentration of the active ingredients. A method for controlling microorganisms, which is characterized by adding to water to disinfect Legionella spp .

  The microorganism control agent of the present invention can achieve a sufficient effect in an actual aqueous system, particularly an open circulation cooling water system, when added at a low concentration, has high safety, no foaming property, and is easy to handle. Microbial control agent.

  In addition, the microorganism control method of the present invention provides a high microorganism control effect when added at a low concentration in an actual water system, is highly safe, has no foaming property, and can be easily implemented. Further, since the addition amount of the microorganism control agent is small, the charging device is simple, and the small device is sufficient, so that the installation is easy and the price is low.

  The microorganism control agent of the present invention comprises at least one selected from 2-phosphonobutane-1,2,4-tricarboxylic acid, 1-hydroxyethylidene-1,1-diphosphonic acid, polymaleic acid, and water-soluble salts thereof. And a compound represented by the following general formula (I) as an active ingredient.

（但し、上記一般式（Ｉ）において、Ｒ_１およびＲ_４は、炭素数１〜４の直鎖若しくは分岐の同一または異なるアルキレン基であり、Ｒ_２およびＲ_５は、水素原子、同一または異なるハロゲン原子、低級アルキル基または低級アルコキシ基であり、Ｒ_３は、炭素数２〜１２の直鎖若しくは分岐のアルキレン基であり、Ｒ_６は、炭素数１〜１８の直鎖若しくは分岐のアルキル基であり、Ｚ⁻は、水中で解離可能な陰イオンである。）

(However, in the above general formula (I), _{R 1} and _{R 4} is a linear or branched, identical or different alkylene group having 1 to 4 carbon atoms, _{R 2} and _{R 5} are hydrogen atoms, the same or different A halogen atom, a lower alkyl group or a lower alkoxy group, R ₃ is a linear or branched alkylene group having 2 to 12 carbon atoms, and R ₆ is a linear or branched alkyl group having 1 to 18 carbon atoms. Z ⁻ is an anion that can be dissociated in water.)

  It is selected from 2-phosphonobutane-1,2,4-tricarboxylic acid, 1-hydroxyethylidene-1,1-diphosphonic acid, polymaleic acid, and water-soluble salts thereof, which are the first component in the microorganism control agent of the present invention. It is preferable that the compounding ratio of the compound represented by the general formula (I) as the second component in the present invention is 1:10 to 100: 1 by weight ratio. If the blending ratio deviates from this range, it may be difficult to obtain a synergistic effect in microbial control by these components. A more preferred range is 1: 5 to 50: 1. Here, these two drugs are dissolved in water and are stable as one drug.

  Here, 2-phosphonobutane-1,2,4-tricarboxylic acid, 1-hydroxyethylidene-1,1-diphosphonic acid, polymaleic acid, and water-soluble salts thereof are appropriately selected and used. In particular, 2-phosphonobutane-1,2,4-tricarboxylic acid and 1-hydroxyethylidene-1,1-diphosphonic acid in terms of stability when dissolved in water to form one agent. preferable.

In the compound represented by the above general formula (I), which is the second component in the present invention, Z ⁻ in the general formula (I) is an anion that can be dissociated in water, for example, chloride ion, bromide ion. , Iodide ion, carboxylate ion, OS ^- O ₂ R ₇ (R ₇ is a lower alkyl group or a substituted or unsubstituted phenyl group).

  Here, the compound represented by the above general formula (I) as the second component is preferably a salt of 1,4-bis (3,3 ′-(1-decylpyridinium) methyloxy) butane. Here, a bromide salt of 1,4-bis (3,3 ′-(1-decylpyridinium) methyloxy) butane is shown as the chemical formula (II).

  Although the addition amount of the microorganism control agent of the present invention varies somewhat depending on the water quality and environment of the target aqueous system, it is usually added so that the total concentration of active ingredients is 1 mg / L or more and 1000 mg / L or less. When the addition amount is less than 1 mg / L, a sufficient microorganism control effect cannot be obtained, and even when added in excess of 1000 mg / L, an improvement in the microorganism control effect commensurate with the increase in the addition amount cannot be obtained. A more preferable addition amount is 2 mg / L or more and 100 mg / L or less.

  In the microorganism control method of the present invention, the first component is selected from 2-phosphonobutane-1,2,4-tricarboxylic acid, 1-hydroxyethylidene-1,1-diphosphonic acid, polymaleic acid, and water-soluble salts thereof. One or more of them and the compound represented by the general formula (I) as the second component may be added to the aqueous water to be controlled by the microorganism, but these two components may not be added simultaneously. Further, for example, the added aqueous system water may be analyzed, and only the component having insufficient water concentration may be added.

  As long as the effects of the present invention are not impaired for the purpose of further improving the properties of the microorganism control agent of the present invention, for example, acrylic acid, maleic acid, methacrylic acid, sulfonic acid, itaconic acid, Or scale inhibitors such as isobutylene polymers, copolymers thereof, phosphoric acid polymers, phosphonic acid, phosphinic acid, or water-soluble salts thereof, such as 5-chloro-2-methyl-4- Isothiazolone compounds such as isothiazoline-3-one, 2-methyl-4-isothiazoline-3-one, 1,2-benzisothiazoline-3-one, hydrogen peroxide, hydrazine, chlorine-based disinfectant (sodium hypochlorite ), Bromine-based and iodine-based fungicides, aldehyde-based compounds such as glutaraldehyde and phthalaldehyde, pyrithione-based compounds, dithi Compounds, thiocyanate compounds such as methylenebisthiocyanate, ionene polymers, bis-quaternary ammonium salts, quaternary ammonium salt compounds other than bis-quaternary ammonium salts, and cation-based compounds such as quaternary phosphonium chlorine compounds Anti-slime agents such as azoles such as benzotriazole and tolyltriazole, amine compounds such as ethylenediamine and diethylenetriamine, aminocarboxylic acid compounds such as nitrilotriacetic acid, ethylenediaminetetraacetic acid and diethylenetriaminepentaacetic acid, such as gluconic acid , Various water treatment agents such as organic carboxylic acids such as citric acid, oxalic acid, formic acid, tartaric acid, phytic acid, succinic acid, and lactic acid can be used together, and such cases are also included in the present invention.

  Examples of the present invention are shown below, but the present invention is not limited to these examples.

<Example 1>
Using the Tsukuba City tap water as supplementary water, the cooling water of an open circulating cooling water system that is operating at about 5-fold concentration is collected, and Legionella pneumophila (ATCC 33152) cultured in the laboratory in the cooling water is 2.4 × 10. It added so that it might become ⁵ pieces / mL, and this was used as test water.

  The chemicals (abbreviations A to E) shown in Table 1 were added to the test water so as to have the addition concentrations shown in Table 2, and then allowed to stand for 24 hours while shaking at 35 ° C and 60 rpm. The number of Legionella spp. Surviving after 24 hours of standing was measured. The results are also shown in Table 2.

  According to Table 2, in the system to which the microbial control agent according to the present invention is added, a very high microbial control effect is obtained synergistically. In particular, 2-phosphonobutane-1,2,4-tricarboxylic acid or 1 as the first component It can be seen that a particularly high microbial control effect can be obtained in a system to which -hydroxyethylidene-1,1-diphosphonic acid is added.

  Polyacrylic acid is a chemical used as a scale inhibitor together with polymaleic acid and phosphonic acids. However, when polyacrylic acid is used as the first component, a high microbial control effect cannot be obtained at the same time. confirmed.

<Example 2>
1,4-Bis (3,3 '-(1-decylpyridinium) methyloxy) butanedibromide is added to the water in the open circulation cooling water system that is operating at about 7 times the concentration using Tokyo city water as make-up water. The addition treatment (treatment A) was continued for 1 month so that the concentration was maintained at 20 mg / L.

  One month after the start of treatment A, the concentration of 1,4-bis (3,3 ′-(1-decylpyridinium) methyloxy) butanedibromide was 10 mg / L, and 1-hydroxyethylidene-1,1-diphosphonic acid The concentration was changed to the addition treatment (B treatment) for maintaining the concentration of 5 mg / L and continued for 1 month.

  At this time, Table 3 shows the results of measuring the number of Legionella and the number of general bacteria in the aqueous water immediately before the start of the A treatment, immediately before the start of the B treatment, and one month after the start of the B treatment.

  It can be seen from Table 3 that a high microbial control effect can be obtained with aqueous water to which the microbial control agent according to the present invention is added, and can be less than the detection limit particularly for Legionella spp.

  In the examples of the present invention, the cooling tower was visually observed during shaking or during actual operation, and it was confirmed that all of them had low foamability.

Claims (2)

One or more selected from 2-phosphonobutane-1,2,4-tricarboxylic acid, 1-hydroxyethylidene-1,1-diphosphonic acid, and water-soluble salts thereof, and 1,4-bis (3,3 ′ A microorganism control agent for sterilizing Legionella spp. In an open-circulation cooling water system comprising : (1-decylpyridinium) methyloxy) butane salt as an active ingredient in a weight ratio of 1: 5 to 50: 1 . The microorganism control agent according to claim 1 is added to the aqueous water of the open circulating cooling water system at a concentration of 2 mg / L or more and 100 mg / L or less as a total concentration of the active ingredients to sterilize Legionella spp. Microbial control method.