JPS59141501A - Antimicrobial agent for service water - Google Patents

Abstract

PURPOSE:An antimicrobial agent useful for sterilizing or controlling microorganisms in service water system such as cooling water system, etc., showing improved synergistic effect with respect to antimicrobial activity, comprising a mixture of 2-bromo-2-nitro-1,3-propanediol with another compound as an active ingredient. CONSTITUTION:2-Bromo-2-nitro-1,3-propanediol shown by the formula I and 1,4- bis(bromoacetoxy)-2-butene shown by the formula II known as anitimicrobial agents are blended in a weight ratio of (1:19)-(19:1), most preferably (4:1)-(1:1), to give an active ingredient. It is effective against Pseudomonas, other bacteria, molds, etc. causing slime, pink bacteria, etc. causing pink slime of paper-making system, capable of preventing slime obstacle such as reduction in heat exchange efficiency of heat exchanger, clogging of channel, or occurrence of paper breakage and spots in paper-making system. The concentration of the two components is 0.1-200mg/l calculated as pure total amount.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an antibacterial agent for killing or suppressing microorganisms in water systems.

In manufacturing industries such as the chemical industry and paper manufacturing industry, large amounts of water are used for cooling water, process water, etc., but in order to compensate for the lack of absolute amount of industrial water, it is necessary to increase the water circulation rate, Wastewater is reused, and the water system becomes a habitat for microorganisms.
This is an environment suitable for growth. Unfortunately, in these water systems, slime is generated due to the proliferation of microorganisms, and for example, in cooling water systems, slime problems such as a decrease in heat transfer efficiency of heat exchangers and blockage of flow channels occur. In addition, as waste paper is reused in the paper manufacturing industry, slime is more likely to occur, and slime problems such as filter paper breakage and the formation of so-called eyeballs occur in the papermaking system. .

Various antibacterial agents are used to remove such slime problems in water systems, but these antibacterial agents account for a high proportion of treatment costs and are more or less toxic. It is desirable to exhibit high antibacterial activity in a small amount. 2-7' lomo 2-
Nitro-1,3-propanediol and 1,4-bis(bromoacetoxy)-2-butene are individually known as antibacterial agents, but from the above perspective, they do not necessarily show excellent effects. I couldn't say it.

This invention is aimed at improving the antibacterial activity of conventional antibacterial agents, including 2-bromo-2-nide 0-1, 3-furopanediol and 1,4-bis(bromoacetoxy)-2-
The object of the present invention is to provide a water-based antibacterial agent that exhibits excellent antibacterial activity due to a synergistic effect by using butene as an active ingredient.

2-furomo 2-nitro-1,5-propanediol is represented by the following formula [I].

HOCHCCHOH·[,I) 02 1.4-bis(bromoacetoxy)-2-butene is represented by the following formula [11].

0 0 2-propanediol and 1,4-bis(bromoacetoxy)-2-butene can coexist as active ingredients in water systems when used as antibacterial agents. Both components may be added to water in a mixed state, or may be added to water simultaneously or separately. The addition method is not particularly limited as long as it can be uniformly dispersed, but it is generally desirable to dissolve it in a solvent that is highly miscible with water, such as dimethylformamide.

At this time, a dispersant may be used if necessary.

The blending ratio of 2-bromo-2-nitro-1,3-propanediol and 1,4-bis(bromoacetoxy)-2-butene is not particularly limited as long as it exhibits a synergistic effect, but in general 1:19 to 19:1 is preferred, especially 9:
1 to 2:5 is more preferred, 4:1 to 1:1
is most preferred.

The antibacterial agent of the present invention may contain only these two types of active ingredients, but if necessary, it may be used in combination with other antibacterial agents, or may contain accelerators such as surfactants, or hydrogen peroxide, etc. Other additives such as release agents may also be included.

Targeted water systems are systems where microbial damage such as slime damage may occur, such as cooling water systems and papermaking systems, but there are no particular restrictions. There are no restrictions, and the targets are Pseudomonas and other bacteria, filamentous fungi, etc. that are generally the cause of slime, and in papermaking systems, in addition to general slime, pink bacteria that are the cause of pink slime are also included.

These microorganisms are sterilized or inhibited by the addition of the antibacterial agent of the present invention. In order to control slime damage, complete sterilization may be used, but it is also sufficient to simply suppress proliferation. Antibacterial in the present invention refers to such an action.

Therefore, the added concentration of the antibacterial agent of the present invention is also a bactericidal concentration when the purpose is sterilization, and an inhibitory concentration when the purpose is inhibition. The specific addition concentration differs depending on the target water system and can be confirmed experimentally for each water system, but in general, the total amount of pure components of the two components is 0.1
~200m9/! That's about it. The antibacterial agent may be added continuously to maintain such a bactericidal or inhibitory concentration, but once the bactericidal or inhibitory concentration is reached, it may take a considerable period of time for the propagation tendency of microorganisms to recover. Therefore, it is more efficient to add intermittently.

The antibacterial agent of the present invention has two components that exhibit a synergistic effect,
Much better antibacterial activity can be obtained than when each is used alone, and microorganisms in water systems can be sterilized or inhibited. Therefore, it is possible to prevent slime failures such as a decrease in heat exchange efficiency of a heat exchanger in a cooling water system, blockage of a flow path, or occurrence of paper breaks and spots in a papermaking system.

Next, embodiments of this invention will be described. In the example, 2
- Bromo-2-nitro-1,3-glopanediol is compound A% 1,4-bis(bromoacetoxy)-2-butene is compound B.

Example 1 Pseudomonas, a typical bacterium that breeds in industrial water
After culturing A. aeruginosa in bouillon medium for 24 hours with shaking, 5 × 10
6 cells 7 m, and then added compounds A and B at different mixing ratios.

After 24 hours, the presence or absence of bacterial growth was determined, and the minimum inhibitory concentration after 24 hours (in terms of pure content...the same applies hereinafter) was determined. The results are shown in Table-1.

As is clear from Table 1, when compounds A and B are used in combination, a synergistic effect is observed over a wide range of blending ratios of 1:19 to 19:1, and the effect is 9:1 to 21:1.
Example 2: Adding 1 part of bouillon culture medium to 9 parts of paper-making white water at a paper mill, and adding 365 parts of compound A and B to 9 parts of white water at a paper mill. After 24 hours, the presence or absence of growth in the number of bacteria was determined.
The minimum inhibitory concentration after time was determined. For comparison, a similar test was conducted in which Compounds A and B were added alone. The results are shown in Table-2.

As is clear from Table 2, a synergistic effect is observed in the mixture of compounds A and B.

Example 6 In the papermaking system of a paper mill where slime damage has occurred, the mixed solution of compounds A and B used in Example 2 was added to white water at a rate of 6 times a day at a rate of 2 m9/I! When the slime was injected for 4 hours at a time (in terms of -C pure content), the number of eyeballs caused by slime decreased from 6 times per day to 0.5 times per day.

Example 4 The mixed solution of compounds A and B used in Example 2 was added to the circulating cooling water system of a chemical factory once every two days so that the amount of water retained was 20m9y#, c pure fraction conversion). As a result, the amount of slime attached to a slime board (10 CrIL x 10 C1n) immersed in the water tank at the bottom of the cooling tower for 60 days was reduced from 35 y- to 6 y-.

From the above results, it can be seen that the antibacterial agent of the present invention exhibits excellent antibacterial activity due to the synergistic effect.

Agent Patent Attorney Sei Yanagi Hara

Claims (4)

[Claims] (1) A water-based antibacterial agent containing 2-bromo-2-nitro-1,6-propanediol and 1,4-bis(bromoacetoxy)-2-butene as active ingredients. (2) Claim 1, wherein the blending ratio of 2-bromo-2-nitro-1,3-propanediol and 1,4-bis(bromoacetoxy)-2-butene is 1=19 to 19:1. Water-based antibacterial agents listed in Section 1. (3) 2-bromo-2-nitro-1,'5-propanediol and 1,4-bis(bromoacetoxy)-2-
The water-based antibacterial agent according to claim 1, wherein the blending ratio of butene is 4:1 to 1:1. (4) The antibacterial agent for a water system according to any one of claims 1 to 3, wherein the water system is a cooling water system or a papermaking system.