JPS592556B2 - Seawater-based sessile organism control agent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for treating seawater by adding a drug formulation containing an effective compound for controlling water-insoluble seawater-based fouling organisms in an organic solvent and a surfactant, and adding benzotriazoles. This invention relates to a method for controlling sessile organisms.

In recent years, industrial use of seawater has been remarkable, and a large amount of seawater is used as cooling water on a one-time basis.

However, with the use of sea and water, problems caused by seawater organisms such as mussels, barnacles, snails, and water bugs have become a major problem. In other words, these seawater-based fouling organisms become a major hindrance because they adhere to the cooling water system and reduce cooling efficiency and promote corrosion of metals. Therefore, compounds that have biocidal or reproductive inhibiting effects (hereinafter referred to as effective control compounds) are added to the seawater cooling water system to kill these seawater organisms or hinder their growth. Methods have been developed to prevent adhesion problems.

These effective pest control compounds can be roughly divided into water-soluble and water-insoluble compounds, but since water-insoluble compounds themselves have low dispersibility in seawater, they usually do not work well in a system. It is added and used in the form of a mixed preparation using an organic solvent and a surfactant with the intention of dispersibility in the water. On the other hand, the seawater near the sea is polluted, especially the seawater taken in the bay often contains sulfide (a compound that liberates S-ions), and the sludge that accumulates in the waterways contains sulfate-reducing bacteria. Sulfides may also be generated due to the action. Since many copper alloys are used in the main parts of seawater cooling systems, pitting corrosion caused by sulfides is particularly problematic. Currently, ferrous sulfate is injected as a countermeasure against corrosion caused by these sulfides. However, there is currently no satisfactory agent for inhibiting pitting corrosion caused by bioadhesion and sulfides. The inventors of the present invention discovered that the flow velocity of seawater, which is most frequently used inside a cooler using copper alloy, is 1 to 2.
．． 5 m/Sec, we focused on research on the most effective anti-fouling organisms and anti-corrosion effects on copper alloys within that range.

As a result, when a compound effective in controlling water-insoluble seawater-based sessile organisms is formulated with an organic solvent and a surfactant and continuously added to a seawater system, it cleans the oxide film that forms on the surface of copper alloy materials. It was found that if a small amount of sulfide was present in the intake seawater, it would cause severe pitting corrosion.

Further, even if ferrous sulfate is injected for the purpose of preventing the attack of sulfides, the formation of a good iron oxide film is inhibited by the organic solvent and surfactant. Furthermore, the benzotriazoles used in this invention have been conventionally used as anticorrosive agents and discoloration inhibitors for copper-based metals, but the concentration used is 10 to 1000 P! It is used at a high concentration of 1,000 ml, and in fact, it is difficult to use it in a seawater cooling system at such a concentration due to running costs, pollution, etc. However, when adding benzotriazoles as well as a drug formulated with an organic solvent and a surfactant to prevent water-insoluble seawater-based fouling organisms, sulfides of copper alloy It has been found that pitting corrosion caused by this method is suppressed, and it is particularly suitable for use in a seawater cooling system where the flow velocity is 1 to 2.5 m/SeC. That is, according to the method of the present invention, even when added in extremely small amounts to seawater, it has a strong control effect on the larvae of mussels, barnacles, water bugs, etc., and also suppresses pitting corrosion of copper alloys caused by sulfides. I can do it. The effective compound for controlling water-insoluble seawater sessile organisms of the present invention is a drug that is water-insoluble, has a controlling effect on larvae of sessile organisms as described above, and can be dissolved or suspended in an organic solvent. Can be used.

Typical compounds include phenol derivatives such as 2,6-di-tert-butyl-p-cresol, 4,4'-thiobis(6-tert-butyl-3-methylphenol), and 2-secondary butyl-p-cresol. Phenyl-N-methylcarbamate, 1-naphthyl-N-methylcarbamate, P-
Carbamate compounds such as chlorobenzyl-N,N-dimethylthiocarbamate, organotin compounds such as tributyltin oxide, tributyltin acetate, triphenyltin chloride, 2,2'-methylenebis-(3,4,6
, monotrichlorophenol), organic chlorine compounds such as tetrachloroisophthalonitrile, N-tetrachloroethylthiotetraphthalimide, 2,4-dichlorophenyl-3'-methoxy-4'-nitrophenyl

'Ether, diphenyl compounds such as 2,4,6-trichlorophenyl-4-nitrophenyl ether, dimethyl-2,
Organic phosphorus compounds such as 2'-dichlorovinyl phosphate, 0,0-dimethyl-0-(3-methyl-4-nitrophenyl) thiophosphate, tetramethylthiuram disulfide, ethylenethiuram monosulfide, P- Examples include organic sulfur compounds such as chlorobenzyl-N,N-dimethyldithiocarbamate, and haloacetic acid ester compounds such as ethylene bisbromoacetate and butoxyethyl monochloroacetate, which can be used alone or in combination. Furthermore, in the method of this invention, the intended purpose can be achieved by continuously adding benzotriazoles in extremely small amounts such that the concentration of benzotriazoles in the seawater cooling system containing copper-based metals is 0.01 to 0.1. can. Representative compounds of benzotriazoles used in this invention include 1,2,3-benzotriazole, 5-methylbenzotriazole, 5-ethylbenzotriazole, 5-n-propylbenzotriazole,
Examples include -isobutylbenzotriazole, 4-methylbenzotriazole, 5-chlorobenzotriazole, 4-nitrobenzotriazole, 5-methoxybenzotriazole, and 5-hydroxybenzotriazole.

These benzotriazoles are usually used in the form of being included in the above-mentioned preparations. In addition, as surfactants, anionic surfactants such as higher fatty acid salts, higher alcohol sulfate ester salts, alkylaryl sulfonates, polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenol ethers, polyoxyethylene alkyl Esters, zorbitan alkyl esters,
Polyoxyethylene sorbitan alkyl esters, polyoxyethylene alkyl amines, polyoxyethylene alkyl amides, polyoxyethylene-polyoxypropylene copolymers, polyoxyethylene-polyoxypropylene alkylene diamine adducts, etc. Examples include ionic surfactants, cationic surfactants such as alkyltrimethylammonium salts, alkyldimethylbenzylammonium salts, and alkylpyridinium salts, and amphoteric surfactants such as alkylbetaines and alkylimidazoline sulfonates. They can be used in combination.

The organic solvents used in the present invention include hydrocarbon solvents such as kerosene, n-paraffin, xylene, solvent typhoid, turpentine oil, and camphor oil, methanol, ethanol, isopropanol, cyclohexanol, benzyl alcohol, and furfuryl. Alcohol solvents such as alcohol, polyhydric alcohol solvents such as ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol, and glycerin, ether solvents such as tetrahydrofuran, furfural, dioxane, and β-naphthyl methyl ether; Examples include ketone solvents such as acetone, methyl isobutyl ketone, and cyclohexanone, ester solvents such as butyl acetate and amine acetate, and nitrogen-containing solvents such as cyclohexylamine, ethanolamine, dimethylformamide, and morpholine.

When formulating the above compounds, the following should be kept in mind.

That is, compounds effective in controlling seawater-based fouling organisms and benzotriazoles are dissolved or suspended in an organic solvent, water and a thickener are added as necessary, and a surfactant is mixed to uniformly dissolve or suspend them. The mixture is formulated into a formulation and continuously added to a seawater cooling system. The effective compounds for controlling sessile organisms used at this time are not limited to one type, but can be used in combination. Further, the organic solvent is appropriately selected based on the physical properties of the compound effective in controlling attached organisms. For example, it is appropriate to use white kerosene for 2,6-ditertiary butyl-P-cresol, and to use dimethylformamide for N-tetrachloroethylthiotetraphthalimide.
One or more surfactants are usually mixed and selected so that the preparation of the present invention can be sufficiently emulsified and dispersed in seawater. When used in combination, it is possible to use an anionic surfactant and a nonionic surfactant, a cationic surfactant and a nonionic surfactant, or a mixture of nonionic surfactants. preferable. Next, examples of formulations according to the present invention will be given.

When the above formulation examples were added to seawater, they all became in an extremely good emulsified state.

Next, the results of investigating the effect of controlling seawater-based fouling organisms and the effect of inhibiting corrosion on copper alloys using each formulation example of the present invention will be shown.

An experimental plant was constructed by connecting a circular pipe waterway with a test net and an Albrack pipe (manufactured by Sumitomo Light Metals) with an inner diameter of 16 mm.
Seawater is flowed into the Albrack pipe at a flow rate of 2 to 2.5 m/
It was flushed with water at Sec.

Then, each mixed preparation was continuously injected, and 0.1 PF of sodium sulfide was simultaneously injected from the front of the alblack tube to produce sulfide (S).
- The degree of pitting corrosion caused by compounds that liberate ions was investigated. That is, especially during the breeding season of mussels,
A one-day waterway experiment was conducted to investigate the effectiveness of controlling sessile organisms and inhibiting pitting corrosion. Below are the amounts added for each preparation (1), the degree of adhesion of mussels (2) and barnacles (1), and the degree of occurrence of pitting (5)
and degrees are shown in order. It should be noted that each preparation was added continuously. Pitting is a form of localized corrosion in which corrosion progresses in the form of dots or small holes, and as the corrosion is concentrated on a part of the metal surface, it may cause holes or cracks in the material. In the table above, the risk is much greater than that of normal uniform corrosion.
In the evaluation of 5), (shallow pitting on the entire surface) means that many small pittings like this are observed on the entire surface of the Albrack pipe and the average depth of the small pits is 0.2 to 0.
It shows that it is 5mm/1r.

Claims (1)

[Claims] 1. Adding a formulation consisting of an effective compound for controlling water-insoluble seawater-based fouling organisms, an organic solvent, and a surfactant to a seawater cooling system containing copper-based metals, and adding 0.01% of benzotriazoles to the seawater cooling pipe system. A method for controlling seawater-based fouling organisms, which comprises adding ~0.1 ppm to control seawater-based fouling organisms while preventing pitting corrosion of copper-based metals.