JPS6097908A - Antimicrobial agent for service water system - Google Patents

Abstract

PURPOSE:An antimicrobial agent preventing disorders of slime such as algal fungi, bacteria, etc. multiflying in a service water system such as cooling water system, paper or pulp making system, etc., showing improved synergistic effect by microbial agents, comprising a hydrazine compound and a guanidine compond. CONSTITUTION:A hydrazine compound containing hydrazino group, and a guanidine compound containing a guanide group, which are antibicrobial agents to be used individually, are blended in a weight ratio of (20:1)-(2:1), to give an antimicrobial agent showing high effect, usable for a long period. Hydrazine, carbohydrazide, maleic hydrazide, polyacrylic hydrazide, etc. are used as the hydrazine compound, and guanidine, its carbonate, acetate, dodecylguanidine hydrochloride, etc. are used as the guanidine compound. The antimicrobial agent is added to service water system as it is done conventional procedure, both the compounds may be preblended in the desired concentration, or they may be added to the system separately. The addition concentration is 10-100mg/l.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water-based antibacterial agent containing a hydrazine compound and a guanidine compound.

In cooling water systems, slime damage is often caused by zooglaia bacteria, algae, filamentous fungi, etc. As a result, this not only results in a decrease in thermal efficiency and deterioration in water flow, but also causes local SG corrosion in mechanical piping and the like.

Furthermore, in paper valve manufacturing systems, slime damage caused by bacteria, filamentous fungi, yeast, etc. mainly occurs during the paper making process. When slime is mixed into pulp slurry as a foreign substance, it not only reduces the quality of the product, but also causes paper breakage and clogging of felt and wire, significantly reducing production efficiency.

In recent years, there has been a trend to operate cooling water systems and pulp and paper manufacturing systems by increasing the concentration of circulating water, and there is a need for more effective antibacterial agents.

that's all! In order to prevent such slime disorders, it is necessary to destroy or inhibit the growth of the slime-constituting bacteria described above, and hydrazine compounds and guanidine compounds have been separately proposed as antibacterial agents for this purpose.

Although hydrazine compounds are effective at high pH values and are effective materials, they cannot be used in high concentrations, especially in open systems, because they are thought to have an effect on the human body. In addition, few guanidine compounds generally exhibit excellent antibacterial properties, and their difoaming properties increase when used in high concentrations, so they are rarely used in cooling water systems.

An object of the present invention is to provide a highly effective antibacterial agent that can sufficiently prevent slime damage in water systems such as cooling water systems and paper valve manufacturing systems.

The inventors have discovered a water-based antibacterial agent that exhibits significantly superior effects when used in combination with the above-mentioned antibacterial agents, which were previously used alone.

That is, the antibacterial agent of the present invention contains a hydrazine compound and a guanidine compound.

Hydrazine-based compounds have a hydrazino group (-NuNH2)k
! hydrazine.

Included are hydrazine hydrate, hydrazine salts and hydrazine derivatives. Hydrazine derivatives include monomethylhydrazine, dimenalhydrazine, hydrazide-based compounds such as maleic hydrazide, carbonic hydrazide, carbohydrazide, and polymers such as polyacrylic hydrazide.

The polyacrylic acid hydrazide is a compound represented by the following formula (1) and preferably has a molecular weight of 500 to 50,000.
less than 10,000.

In the formula, X is a hydrogen atom spanning methyl group, A is acrylamide, methacrylamide, acrylic ester, spanning methacrylic ester, t is 10 to 100 moles, m is 0
~90 mol% is represented by (3), respectively.

In addition, it is also possible to use the above formula (1) in which a structural unit B which is copolymerizable with A is further polymerized. Structural unit B
Examples include the following monomers. Vinyl sulfonic acid, allyl sulfonic acid, styrene sulfonic acid, acrylic glare.

Methacrylic acid, maleic acid, fumaric acid, itaconic acid, cinnamic acid, vinylbenzoic acid, acrylonitrile, styrene, vinyl acetate, etc.

Polyacrylic acid hydrazide can be produced by a known method. One example is obtained by first synthesizing polyacrylamide by a known method, adding an aqueous hydrazine hydrate solution, and reacting at a temperature of 50 to 90°C.

If necessary, the component represented by B can be copolymerized with acrylamide to obtain a terpolymer.

Guanidine is a guanidine compound.

Guanidine carbonate, guanidine nitrate, guanidine acetate, guanidine phosphate, dodecyl (4) guanidine hydrochloride, polyhexamethelene biguanidine hydrochloride, guanidine benzoate, methylguanidine, dimethylguanidine, trimethylguanidine, ethylguanidine, diethyl Derivatives such as guanidine and 1.1'
Mention may be made of all compounds having a guanidino group, such as quaternary ammonium salts such as -iminodi(octamethylene)-diguanidine triacetate.

The composition ratio of the hydrazine compound and the guanidine compound is not particularly limited, but a high effect is exhibited when it is in the range of 20:1 to 2:1.

1. The method of using the agent of the present invention is to add it to the water system in the same manner as in the past, and the two may be mixed in advance to the required concentration or added separately to the system.

The concentration added varies depending on the water system, etc., but is usually 10 or 1.
00■/ is not enough.

As described above, by using a hydrazine-based compound and a guanidine-based compound in combination in a water system, an excellent mutual effect that has not been previously known can be obtained. This is thought to be because the hydrazine-based compound and the guanidine-based compound have different active sites, so a synergistic effect appears, making it difficult for one to develop resistance to the other. As a result, the slime control effect is increased compared to when used alone, and the anti-causal spectrum becomes wider than when used alone. f. Since it is difficult to develop resistance, it can be used for a longer period of time.

In addition, by using both compounds together, handling becomes difficult and reaction heat is not generated. In addition, the combination of both compounds can reduce the toxicity of hydrazine.
It is safe because it is not used repeatedly.

The figures show the results of determining the minimum growth inhibitory concentration (CMIC24) using E. coli according to the example. The test conditions were a peptone-yeast extract-based liquid medium with a pH of 7 (peptone 1f/l,
Yeast extract 11/4i) with 106 E. coli/ff1
7! The cells were inoculated and cultured with shaking at 85°C for 24 hours. The hydrazine compound used here was hydrazine (purity 50%) (A), and the guanidine compound was guanidine acetate (purity 40%, supplied by Ichinichi Fuink Chemical Industry Co., Ltd.).
)(B). As shown in the drawing, the composition ratio of the hydrazine compound (A) and the guanidine compound (B) is 2.
In the range of o:1 to 2:1, the suppressive effect increases synergistically.

Example 2 Regarding four types of bacteria isolated from the paper making system of each building, carbohydrazide (A)'Th
Table 1 shows the results of a comparison of antibacterial activity using polyhexamethylene biguanidine hydrochloride CB) as a guanidine compound. The test conditions were the same as in Example 1. As a result, it is understood that the drug of the present invention has a broad antibacterial spectrum.

(7) Table-1 Antibacterial spectrum MIC, d4) a: Bacteria isolated from high-quality paper making system b: Bacteria isolated from cardboard making system C: Bacteria isolated from paperboard making system d: Bacteria isolated from coated base paper making system Lv Example a Uninvented drug [Hydrazine (purity 40%) (A): Polyhexamethylene biguanidine hydrochloride (purity 60%) (B)
=to=1) was continuously added for one month using a model cooling water blunt so that the number of units per blow water was 159. In this test, the status of resistant bacteria was tested using live bacteria in the circulating water immediately after the start of the test and immediately before the end of the test, and the results are shown in Table 2 (8). From these results, it is understood that the drug of the present invention not only has a high antibacterial activity but also is difficult to develop resistance and can be used for a longer period of time.

Table-2 Model cooling water plant experiment results

[Brief explanation of drawings]

The drawing shows the synergistic effect of using a hydrazine compound and a guanidine compound in combination. Patent applicant Kurita Industries Co., Ltd.

Claims (1)

[Scope of Claims] L A water-based antibacterial agent characterized by containing a hydrazine compound and a guanidine compound. 2. The antibacterial agent according to claim 1, wherein the hydrazine compound is hydrazine. The antibacterial agent according to claim 1, wherein the hydrazine compound is a hydrazide compound. The first hydrazide compound is carbohydrazide. The antibacterial agent according to claim 8, which is at least one selected from maleic acid hydrazide and polyacrylic acid hydrazide. The antibacterial agent according to any one of claims 1 to 4, wherein the irrigation water system is a cooling water system or a pulp and paper manufacturing system.