Composition for slime prevention and method for slime prevention

Abstract

To achieve an efficacy equivalent to or superior to that of traditional organic biocides through the combination of low-cost components.SOLUTION: A composition for slime prevention according to the present invention comprises a chlorine-based oxidizing agent, a sulfamic acid compound, an anionic polymer, an alkali metal salt, and an azole compound.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a slime prevention composition and a slime prevention method.

Background Art

[0002] In a circulating water system of a cooling water system, since the concentration of dissolved salts, nutrient sources, etc. occurs, there may be a case where it becomes an environment in which microorganisms such as bacteria, molds, and algae easily grow. When the viscous secretions secreted by these microorganisms incorporate inorganic substances such as earth and sand, dust, and dirt, slime is generated, which becomes a factor hindering smooth water circulation.

[0003] In order to prevent the generation of slime, the addition of a bactericide to the circulating water system has been studied. For example, Japanese Patent Application Laid-Open No. 7-206609 (Patent Document 1) proposes an organic bactericide containing taurine chloramine as an active ingredient. Since the organic bactericide has a strong penetration power against slime, its progress can be blocked even after the occurrence of slime damage.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, since the organic bactericide is more expensive than other bactericides, when trying to prevent slime relying only on the organic bactericide, the cost burden may be large. Therefore, it is desired to realize a slime prevention composition and a slime prevention method that combine lower-cost components and have the same or higher efficacy as the conventional organic bactericide.

Means for Solving the Problems

[0006] The slime-preventing composition according to the present invention is characterized by containing a chlorine-based oxidizing agent, a sulfamic acid compound, an anionic polymer, an alkali metal salt, and an azole compound.

[0007] The slime-preventing method according to the present invention is characterized by including adding a slime-preventing composition containing a chlorine-based oxidizing agent, a sulfamic acid compound, an anionic polymer, an alkali metal salt, and an azole compound to the water to be treated.

[0008] With the combination of the above components, a slime-preventing composition and a slime-preventing method having efficacy equal to or higher than that of conventional organic bactericides can be realized.

[0009] Further features and advantages of the present invention will become clearer from the following description of exemplary and non-limiting embodiments.

Embodiments for Carrying Out the Invention

[0010] An embodiment of the slime-preventing composition according to the present invention will be described. The slime-preventing composition according to this embodiment contains a chlorine-based oxidizing agent, a sulfamic acid compound, an anionic polymer, an alkali metal salt, and an azole compound.

[0011] The slime-preventing composition according to this embodiment contains a chlorine-based oxidizing agent. The chlorine-based oxidizing agent can be one or more compounds selected from the group consisting of chlorine, metal hypochlorites, metal chlorites, and metal chlorates. The metal hypochlorite can be selected from, but is not limited to, alkali metal hypochlorites (such as sodium hypochlorite and potassium hypochlorite) and alkaline earth metal hypochlorites (such as calcium hypochlorite and barium hypochlorite). The metal chlorite can be selected from, but is not limited to, alkali metal chlorites (such as sodium chlorite and potassium chlorite) and alkaline earth metal chlorites (such as calcium chlorite and barium chlorite). The metal chlorate can be selected from, but is not limited to, alkali metal chlorates (such as sodium chlorate and potassium chlorate) and alkaline earth metal chlorates (such as calcium chlorate and barium chlorate).

[0012] The content of the chlorine-based oxidizing agent is preferably 1.0% by mass or more and 8.0% by mass or less based on the total mass of the slime-preventing composition. When the slime-preventing composition contains a plurality of types of chlorine-based oxidizing agents, the total amount thereof is preferably 1.0% by mass or more and 8.0% by mass or less based on the total mass of the slime-preventing composition.

[0013] The slime-preventing composition according to this embodiment contains a sulfamic acid compound. The sulfamic acid compound can be one or more compounds selected from the group consisting of sulfamic acid, N-substituted sulfamic acids (such as N-methylsulfamic acid, N,N-dimethylsulfamic acid, and N-phenylsulfamic acid), alkali metal salts, alkaline earth metal salts, and ammonium salts of sulfamic acid, and alkali metal salts, alkaline earth metal salts, and ammonium salts of N-substituted sulfamic acids, but is not limited thereto.

[0014] The content of the sulfamic acid compound is preferably 1.0% by mass or more and 10% by mass or less based on the total mass of the slime-preventing composition. When the slime-preventing composition contains a plurality of types of sulfamic acid compounds, the total amount thereof is preferably 1.0% by mass or more and 10% by mass or less based on the total mass of the slime-preventing composition.

[0015] The slime-preventing composition according to this embodiment contains an anionic polymer. The anionic polymer can be one or more compounds selected from the group consisting of polymaleic acid, polyacrylic acid, a copolymer of maleic acid, acrylic acid alkyl vinyl acetate, a copolymer of acrylic acid and 2-acrylamido-2-methylpropanesulfonic acid, a phosphinocarboxylic acid copolymer, 1-hydroxyethylidene-1,1-diphosphonic acid, and 2-phosphonobutane-1,2,4-tricarboxylic acid, but is not limited thereto. Among these, polymaleic acid, phosphinocarboxylic acid copolymer, 1-hydroxyethylidene-1,1-diphosphonic acid, and 2-phosphonobutane-1,2,4-tricarboxylic acid are particularly excellent in the effect of preventing the formation of calcium carbonate. In addition, the copolymer of acrylic acid and 2-acrylamido-2-methylpropanesulfonic acid and the phosphinocarboxylic acid copolymer are particularly excellent in the effect of preventing the formation of calcium phosphate. The anionic polymer preferably contains at least one of a phosphinocarboxylic acid copolymer and polymaleic acid, and more preferably contains a phosphinocarboxylic acid copolymer.

[0016] The content of the anionic polymer is preferably 2.0% by mass or more and 20% by mass or less based on the total mass of the slime-preventing composition. When the slime-preventing composition contains a plurality of types of anionic polymers, the total amount thereof is preferably 2.0% by mass or more and 20% by mass or less based on the total mass of the slime-preventing composition.

[0017] The slime-preventing composition according to this embodiment contains an alkali metal salt. The alkali metal salt can be one or more compounds selected from the group consisting of sodium hydroxide, potassium hydroxide, potassium carbonate, and sodium carbonate, but is not limited thereto.

[0018] The content of the alkali metal salt is preferably 2.0% by mass or more and 10% by mass or less based on the total mass of the slime-preventing composition. When the slime-preventing composition contains a plurality of types of alkali metal salts, the total amount thereof is preferably 2.0% by mass or more and 10% by mass or less based on the total mass of the slime-preventing composition.

[0019] The slime-preventing composition according to this embodiment contains an azole compound. The azole compound can be one or both of benzotriazole and tolyltriazole, but is not limited thereto.

[0020] The content of the azole compound is preferably 0.050% by mass or more and 5.0% by mass or less based on the total mass of the slime-preventing composition. When the slime-preventing composition contains a plurality of types of azole compounds, the total amount thereof is preferably 0.050% by mass or more and 5.0% by mass or less based on the total mass of the slime-preventing composition.

[0021] The slime-preventing composition according to this embodiment may contain other substances in addition to the above substances. Examples of such other substances include solvents such as water, ethylene glycol, diethylene glycol, and propylene glycol, fluorescent agents such as sulfonated pyrene compounds, and water-soluble salts of lithium, but are not limited thereto.

[0022] The slime-preventing composition according to this embodiment preferably has a pH of 13.0 or more.

[0023] The slime-preventing composition according to this embodiment can be suitably used for preventing slime from occurring in a system in a circulating water system such as a cooling water system, a heat storage water system, a dust collection water system, a scrubber water system, etc. Therefore, the slime prevention method according to this embodiment includes adding a slime-preventing composition containing a chlorine-based oxidizing agent, a sulfamic acid compound, an anionic polymer, an alkali metal salt, and an azole compound to the water to be treated.

[0024] 〔Other Embodiments〕 Regarding other configurations as well, it should be understood that all the embodiments disclosed in this specification are illustrative in all respects, and the scope of the present invention is not limited thereby. Those skilled in the art will easily understand that appropriate modifications can be made without departing from the spirit of the present invention. Therefore, other embodiments modified without departing from the spirit of the present invention are naturally included in the scope of the present invention.

Examples

[0025] Hereinafter, the present invention will be further described with reference to examples. However, the following examples do not limit the present invention.

[0026] 〔Preparation of Slime-Preventing Composition〕 (Example 1) Sodium hypochlorite, sulfamic acid, a phosphinocarboxylic acid copolymer, sodium hydroxide, and benzotriazole were dissolved in pure water to prepare a slime-preventing composition according to Example 1. The concentration of each substance in the composition was 3.6% by mass of sodium hypochlorite, 6.0% by mass of sulfamic acid, 10% by mass of the phosphinocarboxylic acid copolymer, 8.3% by mass of sodium hydroxide, and 1.0% by mass of benzotriazole. The balance was pure water.

[0027] (Example 2) A slime-preventing composition according to Example 2 was prepared in the same manner as in Example 1, except that polymaleic acid was used instead of the phosphinocarboxylic acid copolymer. The concentrations of the respective substances in the composition were 3.6% by mass of sodium hypochlorite, 6.0% by mass of sulfamic acid, 10% by mass of polymaleic acid, 8.3% by mass of sodium hydroxide, and 1.0% by mass of benzotriazole. The balance was pure water.

[0028] 〔Evaluation of Slime-Preventing Composition〕 (Example 1) The slime-preventing composition according to Example 1 was added to a cooling water system having a cooling tower, and the cooling water was circulated for 90 days. When the cooling tower after 60 days had elapsed was observed, no noticeable deposits were found on the filler, the lower water tank, the strainer, etc. It was confirmed that the slime-preventing composition according to Example 1 was effective as a slime-preventing composition.

[0029] (Example 2) The evaluation of the slime-preventing composition was carried out in the same manner as in Example 1, except that the slime-preventing composition according to Example 2 was used instead of the slime-preventing composition according to Example 1. When the cooling tower after 60 days had elapsed was observed, although deposits were found, no hindrance to the circulation of the cooling water was observed. When the deposits were analyzed with an energy-dispersive X-ray analyzer, calcium phosphate was detected and calcium carbonate was not detected. It was confirmed that the slime-preventing composition according to Example 2 had the effect of preventing slime derived from calcium carbonate.

Industrial Applicability

[0030] The present invention can be used, for example, for preventing the generation of slime in systems such as cooling water systems, heat storage water systems, dust collection water systems, and scrubber water systems.

Claims

1. A slime prevention composition comprising a chlorine-based oxidizing agent, a sulfamic acid compound, an anionic polymer, an alkali metal salt, and an azole compound.

2. A method for preventing slime, comprising adding a slime-preventing composition containing a chlorine-based oxidizing agent, a sulfamic acid compound, an anionic polymer, an alkali metal salt, and an azole compound to water to be treated.