JP2021046368A - Slime inhibitor composition and slime inhibiting method - Google Patents

Abstract

To provide a slime inhibitor composition that overcomes the drawbacks of a 3-isothiazolone compound, may not cause environmental pollution, and can exhibit a slime inhibitory effect stably for a long time, and a slime inhibiting method that can sustain a slime inhibitory effect.SOLUTION: A slime inhibitor composition is an aqueous preparation that contains 5-chloro-2-methyl-4-isothiazoline-3-one and 2,2,6,6-tetramethylpiperidine-1-oxyl and does not substantially contain a nitric acid compound, a nitrite compound, or an organic solvent, and a slime inhibiting method includes adding the slime inhibitor composition to a treatment object.SELECTED DRAWING: None

Description

The present invention relates to a slime inhibitor composition and a slime inhibitory method, and more particularly to a slime inhibitor composition capable of stably exerting an effect for a long period of time and a slime inhibitory method capable of sustaining the effect.

In various water systems such as circulating cooling water systems and industrial process water systems, various disorders occur due to microorganisms such as bacteria, fungi, and algae.

For example, in an open circulation cooling water system, bacteria such as zooglare bacteria, filamentous bacteria, iron bacteria, sulfur bacteria, nitrifying bacteria, sulfate-reducing bacteria, fungi such as water mold and blue mold, blue-green algae, green algae, diatomaceae, etc. Algae grow and generate ooze-like slime formed by mixing these microorganisms with inorganic substances such as earth and sand and dust. Slime adheres to pipes and equipment in the system, causing not only deterioration of thermal efficiency and deterioration of water flow, but also local corrosion of equipment and pipes. Also, in the water system of the papermaking process, when various bacteria, fungi, algae, etc. proliferate to form slime, defects such as holes, spots, and eyeballs are generated in the product, which deteriorates the product quality and cuts the paper. It causes a decrease in productivity.

Conventionally, various techniques have been proposed in order to prevent damage caused by the above microorganisms, and as a slime control agent, 3-isothiazolin-based compounds, particularly 5-chloro-2-methyl-4-isothiazolin-3-one, have been proposed. The mixture with 2-methyl-4-isothiazolin-3-one has been widely used because it is effective even when added at a low concentration, has a wide antibacterial spectrum, is water-soluble, and is easy to handle (Patent Document 1). And Patent Document 2).

This combination of agents is a slime control agent that is effective against most bacteria, fungi and algae, but 3-isothiazolone compounds are extremely unstable substances by themselves and are stable such as nitrates, magnesium salts and other metal salts. Aqueous formulations stabilized by agents are widely used (see Patent Documents 3 and 4). However, each of these stabilizing substances has problems such as destabilization of polymer emulsions, high cost, and concerns about safety such as carcinogenicity. In addition, ammonia, ammonium compounds, nitrite compounds and nitric acid compounds are designated as harmful substances under the Water Pollution Control Law, and liquids containing them have problems such as restrictions on handling.

As a solution to the above problems, an aqueous composition of a 3-isothiazolone-based compound stabilized by a bromate, which does not contain a nitrate and a nitrite compound (Patent Document 5), does not contain a nitrate, a nitrite, or a magnesium salt. Substantially free of copper ion-stabilized aqueous composition of 3-isothiazolone compound (Patent Document 6), nitrates, nitrites, other metal salts, formaldehyde, formaldehyde-producing substances and non-aqueous solvents, and peroxidation An aqueous composition of a 3-isothiazolone-based compound stabilized by an oxidizing agent such as hydrogen (Patent Document 7) has been proposed. However, bromic acid is a chemical substance suspected to be carcinogenic, and the water quality standard for drinking water has a strict standard value of 0.01 mg / L or less. In addition, copper is a substance for which a wastewater standard of 3 mg / L or less is set in the Water Pollution Control Law, and such highly toxic substances and heavy metals are used as stabilizers in the environment together with slime control agents. It is not preferable to release it. Further, an oxidizing stabilizer such as hydrogen peroxide reacts with other substances to reduce the concentration and lose the stabilizing effect, so that it is not suitable as a substance for stabilizing a 3-isothiazolone compound for a long period of time.

As another method for ensuring the stability of 3-isothiazolone compounds, a method of preparing using an organic solvent such as glycol instead of an aqueous preparation has been known for a long time, but in the preparation using an organic solvent, a large amount of organic solvent is used. Is released into the environment together with the slime control agent, and the released organic solvent becomes a food for microorganisms, which may lead to microbial contamination. A method for stabilizing a 3-isothiazolone compound by forming a clathrate compound using cyclodextrin or the like as a host compound has also been proposed (Patent Document 8), but since the clathrate compound is solid, it is compared with a liquid. Then, it is not easy to handle, and if the clathrate compound of 3-isothiazolone is dissolved in water, its stabilizing effect is lost. In addition, the host compound is an organic substance and may also be a food for microorganisms.

U.S. Pat. No. 4,241,214 Special Publication No. 58-4682 Re-table 2008/146436 Japanese Unexamined Patent Publication No. 2011-12059 Japanese Unexamined Patent Publication No. 8-319279 Japanese Unexamined Patent Publication No. 8-165284 Japanese Unexamined Patent Publication No. 3-188071 Japanese Unexamined Patent Publication No. 5-247011

An object of the present invention is to eliminate the drawbacks of the above-mentioned 3-isothiazolone compound. That is, it is an object of the present invention to provide a slime inhibitor composition capable of stably exerting a slime suppressing effect for a long period of time without fear of environmental pollution, and a slime suppressing method capable of sustaining the slime suppressing effect.

As a result of intensive studies focusing on the relationship between the stabilizer of the 3-isothiazolin compound and the slime-suppressing effect in order to solve the above-mentioned problems, the present inventors have conducted intensive studies on 5-chloro-2-methyl-4. We have found that in a composition containing -isothiazolin-3-one, the sustainability of the slime-suppressing effect is remarkably improved by not containing a specific compound, and the present invention has been reached.

The present invention
(1) Containing 5-chloro-2-methyl-4-isothiazolin-3-one and 2,2,6,6-tetramethylpiperidin-1-oxyl, nitric acid compound, nitrite compound, and organic solvent A slime inhibitor composition, which is an aqueous preparation substantially free of.
(2) The slime inhibitor according to (1), wherein the content of 2,2,6,6-tetramethylpiperidin-1-oxyl is in the range of 0.001 to 2% by mass. Composition.
(3) The slime inhibitor composition according to (1) or (2), which further contains 2-methyl-4-isothiazolin-3-one.
(4) The slime inhibitor composition according to any one of (1) to (3), which is substantially free of magnesium compounds and calcium compounds.
(5) A host that forms an inclusion compound using chloric acid compound, bromic acid compound, iodic acid compound, hydrogen peroxide, heavy metal compound, and 5-chloro-2-methyl-4-isothiazolin-3-one as guest compounds. The slime inhibitor composition according to any one of (1) to (4), which is characterized by substantially not containing a compound.
(6) A slime-suppressing method comprising adding the slime-suppressing agent composition according to any one of (1) to (5) to a treatment target.
(7) When the slime inhibitor composition according to any one of (1) to (5) is added to the aqueous system to be treated, the slime inhibitor is repeatedly added at intervals of a predetermined number of days or more. Method.
Is.

The slime inhibitor composition of the present invention contains 5-chloro-2-methyl-4-isothiazolin-3-one and 2,2,6,6-tetramethylpiperidin-1-oxyl as a stabilizer. By making it an aqueous preparation that does not substantially contain nitric acid compounds, nitrite compounds, and organic solvents, there is no concern about environmental pollution because it does not contain harmful substances under the Water Pollution Control Law, and the conventional 3 -It has become possible to exert a long-term stable slime-suppressing effect that cannot be obtained with isothiazolin-based compounds. Further, as the slime inhibitor composition, 2-methyl-4-isothiazolin-3-one is contained in addition to 5-chloro-2-methyl-4-isothiazolin-3-one, and the magnesium compound and the calcium compound are substantially contained. Inclusive compounds containing chloric acid compound, bromic acid compound, iodic acid compound, hydrogen peroxide, heavy metal compound, and 5-chloro-2-methyl-4-isothiazolin-3-one as guest compounds. By using a formulation that does not substantially contain the host compound to be formed, it is possible to maintain the slime-suppressing effect for a longer period of time, and the slime-suppressing agent composition is more safe for the human body and the environment. It becomes possible to do.

On the other hand, according to the slime-suppressing method of the present invention in which the slime-suppressing agent of the present invention is added to a treatment target, the slime-suppressing effect can be sustained due to the long-term stable slime-suppressing effect. In particular, when it is added to an aqueous system to be treated, the frequency of addition can be set to a predetermined number of days or more, for example, an interval of 2 weeks or more. In this case, the appearance of resistant bacteria can be suppressed and the labor of drug supplementation and the like can be suppressed. Can be reduced.

The slime inhibitor composition of the present invention comprises 5-chloro-2-methyl-4-isothiazolin-3-one and 2,2,6,6-tetramethylpiperidine-1-oxyl, preferably 2-methyl-. It contains 4-isothiazolin-3-one and is substantially free of nitric acid compounds, nitrite compounds, and organic solvents. The slime inhibitor composition of the present invention preferably contains substantially no magnesium compound and calcium compound, and further contains chloric acid compound, bromic acid compound, iodic acid compound, hydrogen peroxide, heavy metal compound, and 5-chloro. It is preferable that the host compound, which forms an inclusion compound using -2-methyl-4-isothiazolin-3-one as a guest compound, is substantially not contained.

The treatment target of the slime inhibitor composition of the present invention is a boiler water system (including a steam condensate system), a cooling water system, a cold / hot water system, a drainage system, a hot water supply / water supply system, a papermaking process water, a pool / hot bath facility, and a waterscape facility. In addition to various water systems such as cutting oil, paint, starch paste, adhesive, pulp, latex, wood, fiber, leather, cosmetics, etc., but not limited to these, it is necessary to suppress the growth of algae. It can be widely applied to the processing target.

The content ratio of 5-chloro-2-methyl-4-isothiazolin-3-one contained in the slime inhibitor composition of the present invention is preferably in the range of about 0.5 to 20% by mass, 1 The range of ~ 15% by mass is more preferable. On the other hand, the content ratio of 2,2,6,6-tetramethylpiperidin-1-oxyl is preferably in the range of about 0.001 to 2% by mass, preferably in the range of 0.01 to 1.5% by mass. Is more preferable.

In the slime suppression method of the present invention, 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one have a concentration of 3-isothiazolinone added to the water system to be treated. The total concentration of the compounds is usually 0.1 mg / L or more and 1000 mg / L or less. The preferred concentration range is 0.5 mg / L or more and 500 mg / L or less, and more preferably 1 mg / L or more and 100 mg / L or less. If the amount of these additions is too small, the effect of the present invention may not be sufficiently obtained, and conversely, even if the amount of these additions is excessive, the effect does not improve as the amount of addition increases, and the running cost increases. Let me.

When a mixture of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one is used as the slime inhibitor composition of the present invention, 5-chloro- The mass ratio of 2-methyl-4-isothiazolin-3-one to 2-methyl-4-isothiazolin-3-one is generally 99: 1 to 0.5: 99.5, preferably 95: 5 to 2:98. , More preferably from 90:10 to 70:30.

The slime inhibitor composition of the present invention is used by adding it to a treatment target. Due to its long-term stable slime-suppressing effect, the slime-suppressing effect can be sustained. When the slime inhibitor composition of the present invention is added to an aqueous system to be treated, a method of continuously adding the slime inhibitor composition so that the concentration of the 3-isothiazolone compound in the aqueous system is maintained at a certain level or higher. , A method of intermittently adding a drug having a high concentration to some extent (hereinafter referred to as a high-concentration intermittent addition method) or a method of using both in combination can be adopted, and both cases are included in the present invention. However, since the appearance of resistant bacteria can be suppressed as much as possible, it is preferable to use a high-concentration intermittent addition method. The frequency of addition may be an interval of a predetermined number of days or more, specifically, an interval of 2 weeks or more, and more preferably an interval of 4 weeks or more. In this case, the preferable addition concentration is 1 mg / L or more and 100 mg / L or less, and more preferably 2 mg / L or more and 20 mg / L or less as the total concentration of the 3-isothiazolone compound.

In the present invention, "substantially free" means that the mixture is not positively added except those contained as impurities in various raw materials and diluting solvents. The specific addition amounts are as follows, for example. "Substantially free of nitric acid compounds, nitrite compounds, and organic solvents" means less than 0.1% by mass, preferably less than 0.01% by mass, based on the mass of the slime inhibitor composition. Most preferably, it means that the nitric acid compound, the nitrite compound, and the organic solvent are contained only in a concentration of less than 0.001% by mass. Further, "substantially free of magnesium compound and calcium compound" means less than 0.1% by mass, preferably less than 0.03% by mass, most preferably 0, based on the mass of the slime inhibitor composition. It means that magnesium compounds and calcium compounds are contained only in a concentration of less than .005% by mass. Further, "a host forming an inclusion compound using chloric acid compound, bromic acid compound, iodic acid compound, hydrogen peroxide, heavy metal compound, and 5-chloro-2-methyl-4-isothiazolin-3-one as guest compounds. "Substantially free of compounds" means a concentration of less than 0.1% by weight, preferably less than 0.01% by weight, most preferably less than 0.001% by weight, based on the weight of the slime inhibitor composition. It means that each substance is not contained only in.

In the present invention, examples of the nitrate compound substantially not contained include nitrate, sodium nitrate, magnesium nitrate, potassium nitrate, calcium nitrate, lithium nitrate, copper nitrate, ammonium nitrate, amyl nitrate and the like, and nitrite compounds substantially not contained. Examples include nitrite, sodium nitrite, magnesium nitrite, potassium nitrite, calcium nitrite, lithium nitrite, copper nitrite, ammonium nitrite, amyl nitrite, ethyl nitrite, butyl nitrite and hexyl nitrite. Can be mentioned.

Examples of the organic solvent substantially not contained include polyols (for example, alkylene oxide glycols such as ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol and polypropylene glycol, 1,3-butanediol, and 1,4-pentane. Alkanediols such as diols and 1,5-pentanediols, and alkanetriols such as glycerol), glycol ethers such as methyl cellosolves, phenyl cellosolves, diethylene glycol monomethyl ethers, dipropylene glycol monomethyl ethers, (C1-C4) alkyl esters of acetic acid and propionic acid. Esters such as (eg, methyl acetate, ethyl acetate, ethyl propionate and butyl acetate) or ethylene carbonate, propylene carbonate, (C2-C4) alcohols (eg, ethanol, n-propanol, isopropanol, n-butanol, isobutyl alcohol, sec-butyl alcohol and tert-butyl alcohol), ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and isophorone, aromatics such as toluene and xylene, and dimethylformamide, dimethylacetamide, dimethylsulfoxide, dioxane, N-methylpyrrolidone and the like. ..

Contains 5-chloro-2-methyl-4-isothiazolin-3-one and 2,2,6,6-tetramethylpiperidin-1-oxyl, preferably further 2-methyl-4-isothiazolin-3-one. However, an aqueous preparation that does not substantially contain a nitric acid compound, a nitrite compound, and an organic solvent constitutes the slime inhibitor composition of the present invention. In addition, the slime inhibitor composition of the present invention comprises a magnesium compound, a calcium compound, a chloric acid compound, a bromic acid compound, an iodic acid compound, a hydrogen peroxide, a heavy metal compound, and 5-chloro-2-methyl-4-. It is preferable that the host compound, which forms an inclusion compound using isothiazolin-3-one as a guest compound, is substantially not contained.

In the present invention, examples of the magnesium compound that is preferably substantially not contained include magnesium chloride, magnesium sulfate, magnesium carbonate, magnesium oxide, magnesium hydroxide and the like, and examples of the calcium compound that is preferably substantially not contained include magnesium chloride, magnesium sulfate, magnesium carbonate, magnesium oxide and the like. Calcium chloride, calcium sulfate, calcium carbonate, calcium oxide, calcium hydroxide and the like can be mentioned.

In the present invention, examples of the chloric acid compound that is preferably substantially free include hypobromous acid, chloric acid, chloric acid, periodic acid and salts thereof (for example, sodium hypobromous acid and sodium chlorite). , Sodium chlorate, sodium perchlorate) and the like, and examples of the bromic acid compound preferably not substantially contained include hypobromous acid, chlorobromic acid, bromic acid, periodic acid and salts thereof (for example,). , Sodium hypobromite, sodium bromine, sodium bromate, sodium perbromate), and examples of the iodous acid compound that is preferably not substantially contained include hypoiodous acid, chloroiodous acid, and iodine. Examples thereof include acids, periodic acids and salts thereof (for example, sodium hypoiodous acid, sodium hypoiodous acid, sodium iodate, sodium periodate) and the like.

In the present invention, the heavy metal compound preferably not substantially contained is a metal having a specific gravity of 4 or more, specifically, a metal selected from silver, lead, copper, iron, chromium, manganese, cobalt, nickel, tin and the like. Chloride, oxide, hydroxide, cyanide, carbonate, sulfate, carboxylate, chelate, etc., specifically, for example, copper chloride, copper sulfate, copper oxide, copper cyanide, etc. Can be mentioned.

Further, in the present invention, cyclodextrin and other host compounds that form a clathrate compound using 5-chloro-2-methyl-4-isothiazolin-3-one as a guest compound, which is preferably not substantially contained, include cyclodextrin and others. Examples include, but are not limited to, tetrakis (hydroxyphenyl) ethane, 4,4'-ethylidenebisphenol, and the like, including 5-chloro-2-methyl-4--isothiazolin-3-one and clathrate compounds. All the formed host compounds are included in the concept of host compounds as used herein.

Although it is not clear exactly why the slime inhibitor composition of the present invention is superior in slime inhibitory effect to the conventional 3-isothiazolone compound-containing composition, bacteria and fungi which are the main constituents of slime are not clear. The fact that it does not substantially contain an organic solvent that is a nutrient source for fungi and that it does not substantially contain nitrate that is a nutrient source for algae, which is also one of the constituent factors, has a great influence. As a result, it is presumed that the difficulty in developing the slime-forming biological flora leads to the long-term slime-suppressing effect.

The slime inhibitor composition of the present invention is appropriately blended with known antiscale agents, slime control agents, anticorrosive agents and the like for the purpose of further improving the characteristics thereof within the range where the effects of the present invention are not impaired. It is possible, and even in that case, it is included in the present invention. For example, acrylic acid-based, maleic acid-based, methacrylic acid-based, sulfonic acid-based, itaconic acid-based, or isobutylene-based polymers and their copolymers, phosphoric acid-based polymers, organic phosphonic acid, and organic phosphinic acid. , Or anti-scale agents such as these water-soluble salts, or aldehydes such as glutaraldehyde and phthalaldehyde, hydrazine, dithiol compounds, thiocyanate compounds such as methylene bisthiocyanate, pyrithione compounds, yonnene polyma, bis-type quaternary Slime inhibitors such as ammonium salts, quaternary ammonium salts other than bis-type quaternary ammonium salts, cationic compounds such as quaternary phosphonium salts, azoles such as benzotriazole and tolyltriazole, and amines such as ethylenediamine and diethylenetriamine. Various compounds such as aminocarboxylic acid compounds such as nitrilo triacetic acid, ethylenediamine tetraacetic acid and diethylenetriamine pentaacetic acid, organic carboxylic acids such as gluconic acid, citric acid, oxalic acid, formic acid, tartaric acid, phytic acid, amber acid and lactic acid. It is possible to use the above drugs in combination.

5-Chloro-2-methyl-4-isothiazolin-3-one, 2,2,6,6-tetramethylpiperidin-1-oxyl, and 2-methyl-4-isothiazolin- satisfying the conditions of the present invention. Examples of the 3-one mixed preparation include ZONEN-NX manufactured by Chemicrea Co., Ltd. (detailed components have not been published at the time of filing of the present application). Sonnen NX contains nitrate compounds, nitrite compounds, organic solvents, magnesium compounds, calcium compounds, chloric acid compounds, bromine acid compounds, iodic acid compounds, hydrogen peroxide, heavy metal compounds, and 5-chloro-2-methyl-4. It corresponds to the slime inhibitor composition of the present invention, which does not substantially contain all of the host compound forming the inclusion compound using −isothiazolin-3-one as a guest compound.

Sonnen NX contains nitrate compounds, nitrite compounds, organic solvents, magnesium compounds, calcium compounds, chloric acid compounds, bromine acid compounds, iodic acid compounds, hydrogen peroxide, heavy metal compounds, and 5-chloro-2-methyl-4. Although it does not contain substantially all of the host compounds that form inclusion compounds with −isothiazolin-3-one as a guest compound, its storage stability is general purpose that it contains a nitrate compound as a stabilizer. It is at the same level as a mixed preparation of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one, for example, Kason WT manufactured by Dow Chemical Co., Ltd. On the other hand, the slime-suppressing effect is remarkably superior to that of the conventional 3-isothiazolone-based compound-containing composition.

Table 1 shows the composition of Sonnen NX and the results of the storage stability test, along with a comparison with other 3-isothiazolone preparations. Here, Comparative Formulation 1 is a conventionally known aqueous preparation obtained by blending 3-isothiazolone with magnesium nitrate and magnesium chloride to stabilize it, and Comparative Formulation 2 is a comparative preparation 1 in which the blending amounts of magnesium nitrate and magnesium chloride are adjusted. It is an aqueous preparation reduced to 1% each. Further, the comparative preparation 3 is a conventionally known organic solvent preparation in which 3-isothiazolone is stabilized by using dipropylene glycol as a solvent, and the comparative preparation 4 is the concentration of dipropylene glycol as an organic solvent in the comparative preparation 3. Is an aqueous preparation in which the amount of water is reduced to 1% and the balance is water. The storage stability test is a visual observation result of the appearance when stored in a constant temperature chamber at 55 ° C. in a closed state.

-CMIT: 5-chloro-2-methyl-4-isothiazolin-3-one-TEMPO: 2,2,6,6-tetramethylpiperidin-1-oxyl-MIT: 2-methyl-4-isothiazolin-3-one・ Oxidizing substance: Total of chloric acid compound, bromic acid compound, iodic acid compound, hydrogen peroxide ・ Host compound: 5-chloro-2-methyl-4-isothiazolin-3-one as guest compound to form inclusion compound Host compound ・ DPG: Dipropylene glycol ・ The concentrations in the table are all mass percent, and the rest is water.
-The nitrate compounds of Comparative Formulations 1 and 2 are derived from magnesium nitrate added as a stabilizer, and the total hardness is derived from magnesium nitrate and magnesium chloride added as stabilizers.

As shown in Table 1, although Sonnen-NX does not contain a conventionally known stabilizer for 3-isothiazolone compounds, it is a conventionally known aqueous preparation, Comparative Preparation 1, and a conventionally known organic solvent. It shows the same level of storage stability as Comparative Preparation 3, which is a preparation. On the other hand, as is clear from the storage stability test results of the comparative preparation 2 and the comparative preparation 4, in the conventional composition, the concentration of the nitric acid compound and the magnesium compound is simply reduced, or the concentration of the organic solvent serving as a nutrient source for microorganisms is adjusted. If it is reduced, it becomes difficult to ensure the stability of the 3-isothiazolone compound.

Although the present invention has been described above with reference to preferred embodiments, the slime inhibitor composition and slime inhibitor method of the present invention are not limited to the configurations of the above embodiments. Those skilled in the art can appropriately modify the slime inhibitor composition and the slime inhibitory method of the present invention according to conventionally known findings. Such modifications are, of course, included in the category of the present invention as long as they have the constitution of the slime inhibitor composition or the slime suppressing method of the present invention.

Examples of the slime inhibitor of the present invention will be specifically described below, but the present invention is not limited thereto.

<Example 1, Comparative Examples 1 to 3>
Test water collected from the cooling water system for cooling at a certain pharmaceutical factory in operation was dispensed, and Sonnen NX (manufactured by Chemicrea Co., Ltd.) was used as Example 1 and Caisson WT (Dow Chemical Co., Ltd.) was used as Comparative Example 1. As Comparative Example 2, Caisson LX (manufactured by Dow Chemical Co., Ltd.) was added so that the addition concentration as a preparation was 5 mg / L, and the mixture was left to stir at room temperature. Comparative Example 3 is a control group to which no drug was added. The amount of microorganisms in the test water was evaluated by measuring the adenosine triphosphate (ATP) concentration in the test water over time with an ATP analyzer (AF-100 manufactured by DKK-TOA CORPORATION). At this time, the lower the ATP concentration, the smaller the amount of microorganisms. The results are shown in Table 2 (unit: pmol / L).

Kason WT is a 3-isothiazolin containing 10% 5-chloro-2-methyl-4-isothiazolin-3-one, 4% 2-methyl-4-isothiazolin-3-one, and 20% magnesium nitrate. An aqueous formulation, Kason LX is a dipropylene glycol of 3-isothiazolinone containing 19% 5-chloro-2-methyl-4-isothiazolin-3-one and 6% 2-methyl-4-isothiazolin-3-one. It is a formulation.

In Caisson WT, which is a conventionally known 3-isothiazolone preparation, the ATP concentration increased over time from the 24th day onward, and the growth of microorganisms was confirmed. In addition, the ATP concentration of caisson LX increased from the 11th day onward, and the growth of microorganisms was confirmed, and the ATP concentration became higher from the 24th day onward as compared with the drug-free group. On the other hand, Sonnen NX, which is the 3-isothiazolone preparation of the present invention, had a low ATP concentration even after 62 days, and the slime suppressing effect was maintained.

<Examples 2 and 3, Comparative Examples 4 to 7>
The test water collected from the cooling water for the refrigerator of a certain food factory in operation was dispensed, and the chemicals shown in Table 3 were added to the test water so that the concentration of each drug added as a preparation was the concentration shown in Table 3. .. Then, the mixture was left to stir at room temperature, and the ATP concentration of the test water was measured with an ATP analyzer (AF-100 manufactured by DKK-TOA CORPORATION) over time. The results are shown in Table 3 (unit: pmol / L).

In Caisson WT, which is a conventionally known 3-isothiazolone preparation, the ATP concentration increased with time after 18 days, and the growth of microorganisms was confirmed. In addition, the ATP concentration of caisson LX increased over time after 18 days, and the growth of microorganisms was confirmed. Compared to the drug-free group, the ATP concentration was significantly higher in the measurement after 60 days, and the added drug concentration was higher. The higher the value, the higher the ATP value. On the other hand, Sonnen NX, which is the 3-isothiazolone preparation of the present invention, had a low ATP concentration even after 60 days, and the slime suppressing effect was maintained.

From the results of Examples 1 to 3 and Comparative Examples 1 to 7 described above, the slime inhibitor composition of the present invention, which is an aqueous preparation substantially free of nitric acid compounds, nitrite compounds, and organic solvents. However, it is clear that it is superior in long-term slime-suppressing effect as compared with the conventionally known 3-isothiazolone preparation.

<Examples 4 and 5, Comparative Examples 8 to 12>
The effect on the biofilm (= adhered static slime) was evaluated using a simulation test device for the cooling tower (installed outdoors: the amount of water in the water system was 60 L and circulated by a pump). After immersing a test piece made of polyvinyl chloride in the mock test device and adding the agents shown in Table 4 so that the concentration of each drug added as a preparation becomes the concentration shown in Table 4, the mock test device is used for 20 days. I drove. Twenty days later, the test piece was taken out, ^{the biofilm adhering to the surface of the test piece (10 cm 2} ) was wiped off with a sterile cotton swab and resuspended in 10 mL of sterile ion-exchanged water, and the ATP concentration of the ion-exchanged water was measured by an ATP analyzer (Toa). It was measured with AF-100) manufactured by DKK-TOA CORPORATION. The results are shown in Table 4 (unit: pmol / L).

It is understood that the ATP concentration of Sonnen NX, which is the 3-isothiazolone preparation of the present invention, is low, and the adhesion of biofilm can be suppressed for a long period of time. On the other hand, the organic solvent type caisson LX had a high ATP concentration similar to that in the drug-free group, and the ATP value tended to increase as the addition amount increased.

From the results of Example 4, Example 5 and Comparative Examples 8 to 12, the slime inhibitor composition of the present invention, which is an aqueous preparation substantially free of nitric acid compound, nitrite compound, and organic solvent, is found. It is clear that it is superior in the long-term adhesion suppressing effect of the biofilm as compared with the conventionally known 3-isothiazolone compound-containing composition.

Since the slime inhibitor composition of the present invention has a stable slime inhibitory effect for a long period of time and does not substantially contain nitric acid compounds and nitrite compounds, it is subject to the restrictions imposed by the Water Pollution Control Law. It can be widely used as a slime inhibitor for various water-based and various industrial products.

Claims (7)

Containing 5-chloro-2-methyl-4-isothiazolin-3-one and 2,2,6,6-tetramethylpiperidin-1-oxyl, nitric acid compounds, nitrite compounds, and organic solvents, substantially A slime inhibitor composition, which is an aqueous preparation that does not contain nitrous acid. The slime inhibitor composition according to claim 1, wherein the content of 2,2,6,6-tetramethylpiperidine-1-oxyl is in the range of 0.001 to 2% by mass. The slime inhibitor composition according to claim 1 or 2, further comprising 2-methyl-4-isothiazolin-3-one. The slime inhibitor composition according to any one of claims 1 to 3, wherein the slime inhibitor composition is substantially free of magnesium compounds and calcium compounds. Chloric acid compounds, bromic acid compounds, iodic acid compounds, hydrogen peroxide, heavy metal compounds, and host compounds that form inclusion compounds with 5-chloro-2-methyl-4-isothiazolin-3-one as guest compounds. The slime inhibitor composition according to any one of claims 1 to 4, wherein the slime inhibitor composition is substantially not contained. A slime-suppressing method comprising adding the slime-suppressing agent composition according to any one of claims 1 to 5 to a treatment target. A method for suppressing slime, which comprises repeatedly adding the slime inhibitor composition according to any one of claims 1 to 5 at intervals of a predetermined number of days or more when it is added to an aqueous system to be treated.