JPH0232247B2 - YOSUIKEINOKOKINZAI - Google Patents

Description

[Detailed description of the invention]

This 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 has become an environment suitable for the inhabitation and proliferation of microorganisms. For this reason, in these water systems, slime is generated due to the proliferation of microorganisms, and for example, in cooling water systems, slime failures such as a decrease in heat transfer efficiency of heat exchangers and blockage of flow paths occur. In addition, as waste paper is reused in the paper industry, slime is more likely to be generated, and slime problems such as paper breakage and so-called spots in the papermaking system are occurring. Various antibacterial agents are used to remove such slime problems in water systems, but these antibacterial agents account for a high proportion of the treatment cost and are more or less toxic, so they can only be used in small amounts. It is desired that they exhibit high antibacterial activity. 2-Bromo-2-nitro-1,3-propanediol and 1,4-bis(bromoacetoxy)-2-butene are known as antibacterial agents when used alone, but from the above point of view, they are not necessarily superior. It could not be said that it was effective. This invention is aimed at improving the antibacterial activity of conventional antibacterial agents.
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 propanediol and 1,4-bis(bromoacetoxy)-2-butene together as active ingredients. 2-bromo-2-nitro-1,3-propanediol is represented by the following formula. 1,4-bis(bromoacetoxy)-2-butene is represented by the following formula. 2-bromo-2-nitro-1,3-propanediol and 1,4-bis(bromoacetoxy)
-2-Butene only needs to coexist as an active ingredient in the water system when used as an antibacterial agent.
Both components may be added to the water in a mixed state, or may be added to the 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 dimethyl formamide. At this time, a dispersant can be used if necessary. 2-bromo-2-nitro-1,3-propanediol and 1,4-bis(bromoacetoxy)-2
- The blending ratio of butene is not particularly limited as long as it shows a synergistic effect, but generally it is 1:19 to 19:1.
1 is preferred, particularly 9:1 to 2:3 is more preferred, and 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. The composition may further contain other additives such as additives. The target water system is a system in which microbial damage such as slime damage may occur, such as a cooling water system or a papermaking system, but there are no particular limitations. There are also no restrictions on the microorganisms that can be targeted for antibacterial treatment, such as Pseudomonas, other bacteria, and filamentous fungi that are generally the cause of slime. It will be done. 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, and the term "antibacterial" in the present invention refers to such 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 additive concentration varies depending on the target water system, so it can be confirmed experimentally for each water system, but in general, the total amount of the pure components of the two components is about 0.1 to 200 mg/concentration. It is. 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 two components contained in the antibacterial agent of the present invention exhibit a synergistic effect, resulting in far superior antibacterial activity than when each is used alone, and can sterilize or suppress microorganisms in a water system. 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 examples, 2-bromo-2-nitro-1,3-propanediol is designated as Compound A, and 1,4-bis(bromoacetoxy)-2-butene is designated as Compound B. Example 1 Pseudomonas aeruginosa, a typical bacterium that grows in industrial water, was cultured with shaking in a broth medium for 24 hours, and then a new broth medium (PH7) was cultured.
Compounds A and B were added to the solution at a concentration of 5 x 10 ⁶ cells/ml, and the mixing ratio was changed. After 24 hours, the presence or absence of bacterial growth was determined, and the minimum inhibitory concentration after 24 hours was determined. (purity conversion...the same applies below) was calculated. The results are shown in Table-1. As is clear from Table 1, compounds A and B
When used in combination, a synergistic effect was observed over a wide range of blending ratios of 1:19 to 19:1, the effect was even greater at 9:1 to 2:3, and the greatest at 4:1 to 1:1.

[Table] Example 2 1 part of bouillon culture medium to 9 parts of papermaking white water at a paper mill
After adding 1 part, a mixed solution of compounds A and B (5 parts each of compounds A and B dissolved in 90 parts of N-dimethylformamide) was added, and after 24 hours, the presence or absence of growth in the number of bacteria was determined. The minimum inhibitory concentration after 24 hours 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, the mixed solution of compounds A and B has a synergistic effect.

[Table] Example 3 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 2 mg/(purity equivalent) three times a day. When the slime was injected for 4 hours at a time, the number of eyeballs caused by slime decreased from 3 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 at a rate of 20% of the amount of water held.
mg/(converted to pure content) once every two days, the amount of slime attached to a slime board (10 cm x 10 cm) immersed in the water soda at the bottom of the cooling tower for 30 days was lower than that of the conventional method. Reduced from 35g to 3g. The above results show that the antibacterial agent of the present invention exhibits excellent antibacterial activity due to the synergistic effect.

Claims (1)

[Scope of Claims] 1. A water-based antibacterial agent containing 2-bromo-2-nitro-1,3-propanediol and 1,4-bis(bromoacetoxy)-2-butene as active ingredients. 2 The blending ratio of 2-bromo-2-nitro-1,3-propanediol and 1,4-bis(bromoacetoxy)-2-butene is 1:19 to 19:1
A water-based antibacterial agent according to claim 1. 3 The blending ratio of 2-bromo-2-nitro-1,3-propanediol and 1,4-bis(bromoacetoxy)-2-butene is 4:1 to 1:1
A water-based antibacterial agent according to claim 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.