Water treatment agent composition and water treatment method

Abstract

To provide a water treatment agent composition which comprises water, an isothiazoline-based microbicide and a halogenated aliphatic nitroalcoholic microbicide in which stability of active ingredients is good and to provide a water treatment method using the water treatment agent composition.SOLUTION: There is provided a water treatment agent composition which comprises water, an isothiazoline-based microbicide, a halogenated aliphatic nitroalcoholic microbicide and a polymer containing at least a monomer unit of formula (1), wherein the isothiazoline-based microbicide contains 5-chloro-2-methyl-4-isothiazolin-3-one and contains 0.05 times or more the halogenated aliphatic nitroalcoholic microbicide by mass ratio to 5-chloro-2-methyl-4-isothiazolin-3-one. (wherein, R1 represents a hydrogen atom or a methyl group, X1 represents a hydrogen atom, a monovalent or divalent metal atom, an ammonium group or an organoammonium group.)SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a water treatment agent composition that can be used, for example, in sterilization treatment in an aqueous system, and a water treatment method using the water treatment agent composition.

Background Art

[0002] As a cooling water treatment agent used in industrial water systems such as cooling water, a water treatment agent composition containing an isothiazolone-based compound as a bactericide is known.

[0003] For example, Patent Document 1 discloses an antibacterial and algicidal agent containing 2-bromo-2-nitro-1,3-propanediol and one or more of specific acetic acid derivatives or one or more of specific isothiazolone compounds as active ingredients.

[0004] Patent Document 2 discloses an industrial bactericide composition containing one or more isothiazolone-based bactericides, a halogenated aliphatic nitroalcohol-based bactericide such as 2-bromo-2-nitro-1,3-propanediol, a pH buffer, bromate, and water, and having a pH in the range of 2.6 or more and less than 3.5.

[0005] However, the stabilization of a water treatment agent composition containing an isothiazolone-based bactericide and a halogenated aliphatic nitroalcohol-based bactericide as active ingredients is not sufficient, and there is a problem that the active ingredients decompose when made into an aqueous solution preparation.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] An object of the present invention is to provide a water treatment agent composition containing water, an isothiazoline-based bactericide, and a halogenated aliphatic nitroalcohol-based bactericide, which has good stability of active ingredients, and a water treatment method using the water treatment agent composition.

Means for Solving the Problems

[0008] The present invention contains water, an isothiazoline-based bactericide, a halogenated aliphatic nitroalcohol-based bactericide, and a polymer containing at least a monomer unit of formula (1), wherein the isothiazoline-based bactericide contains 5-chloro-2-methyl-4-isothiazolin-3-one, and the halogenated aliphatic nitroalcohol-based bactericide is contained in a mass ratio of 0.05 times or more with respect to the 5-chloro-2-methyl-4-isothiazolin-3-one, which is a water treatment agent composition.

Chemical formula

[0009] The present invention contains water, an isothiazoline-based bactericide, a halogenated aliphatic nitroalcohol-based bactericide, and a copolymer containing at least a monomer unit of formula (1) and a monomer unit of formula (2), wherein the isothiazoline-based bactericide contains 5-chloro-2-methyl-4-isothiazolin-3-one, and the halogenated aliphatic nitroalcohol-based bactericide is contained in a mass ratio of 0.05 times or more with respect to the 5-chloro-2-methyl-4-isothiazolin-3-one, which is a water treatment agent composition.

Chemical formula

[0010] In the water treatment agent composition, it is preferable to contain the halogenated aliphatic nitroalcohol-based bactericide in a mass ratio of 1.0 times or more with respect to the 5-chloro-2-methyl-4-isothiazolin-3-one.

[0011] It is preferable that the pH of the water treatment agent composition is less than 5.0.

[0012] In the water treatment agent composition, it is preferable that the halogenated aliphatic nitroalcohol-based bactericide contains 2-bromo-2-nitropropane-1,3-diol.

[0013] In the water treatment agent composition, it is preferable to further contain a fluorescent substance.

[0014] The present invention is a water treatment method for performing water treatment using the above water treatment agent composition. [Advantages of the Invention]

[0015] According to the present invention, in a water treatment agent composition containing water, an isothiazoline-based bactericide, and a halogenated aliphatic nitroalcohol-based bactericide, it is possible to provide a water treatment agent composition with good stability of the active ingredient, and a water treatment method using the water treatment agent composition. [Embodiments for Carrying Out the Invention]

[0016] Embodiments of the present invention will be described below. This embodiment is an example of implementing the present invention, and the present invention is not limited to this embodiment.

[0017] The water treatment agent composition according to this embodiment contains water, an isothiazoline-based bactericide, a halogenated aliphatic nitroalcohol-based bactericide, and a polymer containing at least the monomer unit of formula (1), wherein the isothiazoline-based bactericide contains 5-chloro-2-methyl-4-isothiazolin-3-one, and contains the halogenated aliphatic nitroalcohol-based bactericide in a mass ratio of 0.05 times or more with respect to 5-chloro-2-methyl-4-isothiazolin-3-one.

Chemical formula

[0018] Further, the water treatment agent composition according to this embodiment contains water, an isothiazoline-based bactericide, a halogenated aliphatic nitroalcohol-based bactericide, and a copolymer containing at least the monomer unit of formula (1) and the monomer unit of formula (2), wherein the isothiazoline-based bactericide contains 5-chloro-2-methyl-4-isothiazolin-3-one, and contains the halogenated aliphatic nitroalcohol-based bactericide in a mass ratio of 0.05 times or more with respect to 5-chloro-2-methyl-4-isothiazolin-3-one.

Chemical formula

Chemical formula

[0019] As described above, the inventors have found that the stabilization of the water treatment agent composition containing the isothiazoline-based bactericide and the halogenated aliphatic nitroalcohol-based bactericide is not sufficient, and when it is made into an aqueous solution preparation, the isothiazoline-based bactericide as the active ingredient decomposes. In the water treatment agent composition in which water, the isothiazoline-based bactericide and the halogenated aliphatic nitroalcohol-based bactericide are formulated into one agent, it has been found that by blending a specific polymer, the stability of the active ingredient becomes good.

[0020] The water is not particularly limited, and examples thereof include pure water and ultrapure water.

[0021] The isothiazoline-based bactericide contains 5-chloro-2-methyl-4-isothiazolin-3-one (CMI). As the isothiazoline-based bactericide, 5-chloro-2-methyl-4-isothiazolin-3-one (CMI) may be used alone, or CMI and other isothiazoline-based bactericides such as 2-methyl-4-isothiazolin-3-one (MIT), 2-ethyl-4-isothiazolin-3-one, 2-propyl-4-isothiazolin-3-one, 2-isopropyl-4-isothiazolin-3-one, 2-n-octyl-4-isothiazolin-3-one, 5-bromo-2-methyl-4-isothiazolin-3-one, 5-chloro-2-ethyl-4-isothiazolin-3-one, 5-bromo-2-ethyl-4-isothiazolin-3-one, 5-chloro-2-n-octyl-4-isothiazolin-3-one, 5-bromo-2-n-octyl-4-isothiazolin-3-one may be used in combination.

[0022] There are no particular restrictions on the halogenated aliphatic nitroalcohol-based bactericides. For example, chlorinated aliphatic nitroalcohol-based bactericides such as 2,2-dichloro-2-nitroethanol and 2-chloro-2-nitropropane-1,3-diol, and brominated aliphatic nitroalcohol-based bactericides such as 2-bromo-2-nitropropane-1,3-diol (BNPD), 2,2-dibromo-2-nitroethanol, and 2-bromo-2-nitropropane-1,3-diol can be mentioned. Among these, 2-bromo-2-nitropropane-1,3-diol (BNPD) is preferred from the viewpoint of stability in the formulation and the like. The halogenated aliphatic nitroalcohol-based bactericides may be used alone or in combination of two or more thereof.

[0023] The polymer to be blended in the water treatment agent composition according to the present embodiment is a polymer containing at least the monomer unit of formula (1), or a copolymer containing at least the monomer unit of formula (1) and the monomer unit of formula (2). There are no particular restrictions, and examples include homopolymers containing the monomer unit of formula (1), binary copolymers containing the monomer unit of formula (1) and the monomer unit of formula (2), and polymers such as terpolymers containing the monomer unit of formula (1), the monomer unit of formula (2), and the monomer unit of the following formula (3).

[0024] [Chemical formula] (In formula (3), R 3 represents a hydrogen atom or a methyl group, and X 3 and X 4 each independently represent a hydrogen atom or an alkyl group, provided that at least one of them is an alkyl group.)

[0025] Examples of the organic ammonium salts in formulas (1) and (2) include alkylammonium groups or (hydroxy)alkylammonium groups having an alkyl group or a hydroxyalkyl group with 1 to 4 carbon atoms.

[0026] Examples of the monovalent or divalent metal salts in formulas (1) and (2) include sodium salts, potassium salts, calcium salts, magnesium salts, and the like.

[0027] X in formula (2) 2 When X is an alkylsulfonic acid group or a salt thereof, the alkyl group is preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 8 carbon atoms. X 2 When X is an arylsulfonic acid group or a salt thereof, the aryl group is preferably an aryl group or arylalkyl group having 6 to 10 carbon atoms.

[0028] As the alkyl group in formula (3), an alkyl group having 1 to 10 carbon atoms is preferable, and an alkyl group having 1 to 8 carbon atoms is more preferable.

[0029] As the weight ratio of the monomer units in the binary copolymer containing the monomer unit of formula (1) and the monomer unit of formula (2), for example, it is 1 to 99:99 to 1.

[0030] As the weight ratio of the monomer units in the terpolymer containing the monomer unit of formula (1), the monomer unit of formula (2), and the monomer unit of formula (3), for example, it is 1 to 98:1 to 98:1 to 98.

[0031] The weight average molecular weight of the above polymer is, for example, in the range of 200 to 100,000, preferably in the range of 1,000 to 30,000, and more preferably in the range of 1,500 to 20,000. If the weight average molecular weight is less than 200, the stabilizing effect of the active ingredient may decrease, and if it exceeds 100,000, the viscosity may be too high and difficult to handle.

[0032] Examples of the polymer include polyacrylic acid (PAA), a binary copolymer of acrylic acid and 2-acrylamido-2-methylpropanesulfonic acid (AA / AMPS), a terpolymer of acrylic acid, 2-acrylamido-2-methylpropanesulfonic acid and t-butylacrylamide (AA / AMPS / t-BAM), and a terpolymer of phosphonic acid, acrylic acid and 2-acrylamido-2-methylpropanesulfonic acid (PA / AA / AMPS). Among these, from the viewpoint of the stabilizing effect of the active ingredient, etc., a binary copolymer of acrylic acid and 2-acrylamido-2-methylpropanesulfonic acid (AA / AMPS) and a terpolymer of acrylic acid, 2-acrylamido-2-methylpropanesulfonic acid and t-butylacrylamide (AA / AMPS / t-BAM) are preferred.

[0033] In the water treatment agent composition, the blending amount of the above polymer is, for example, in the range of 0.1 to 50% by mass as the solid content with respect to the total amount of the composition, preferably in the range of 1 to 50% by mass, and more preferably in the range of 1 to 40% by mass. When the blending amount of the above polymer is less than 0.1% by mass, the stabilizing effect of the active ingredient may not be obtained, and when it exceeds 50% by mass, the production cost may increase.

[0034] In the water treatment agent composition, the blending amount of 5-chloro-2-methyl-4-isothiazolin-3-one, which is an isothiazoline-based bactericide, is, for example, in the range of 0.01 to 8.0% by mass with respect to the total amount of the composition, preferably in the range of 0.1 to 5.0% by mass, and more preferably in the range of 0.5 to 2.0% by mass. When the blending amount of the isothiazoline-based bactericide is less than 0.01% by mass, the bactericidal effect may not be obtained, and when it exceeds 8.0% by mass, precipitates may occur. In the water treatment agent composition according to the present embodiment, even when the blending amount of the isothiazoline-based bactericide is higher than the blending amount of the isothiazoline-based bactericide in the conventional water treatment agent composition in the range of 0.5 to 2.0% by mass, the stability of the active ingredient is good.

[0035] In the water treatment agent composition, the blending amount of the halogenated aliphatic nitroalcohol - based bactericide is, for example, in the range of 0.01 to 5.0% by mass with respect to the total amount of the composition, preferably in the range of 0.1 to 5.0% by mass, and more preferably in the range of 0.5 to 2.0% by mass. When the blending amount of the halogenated aliphatic nitroalcohol - based bactericide is less than 0.01% by mass, the bactericidal effect or the stabilizing effect of the active ingredient may not be obtained. When it exceeds 5.0% by mass, the amount of chemicals used may increase. In the water treatment agent composition according to the present embodiment, even when the blending amount of the halogenated aliphatic nitroalcohol - based bactericide is higher than the blending amount of the halogenated aliphatic nitroalcohol - based bactericide in the conventional water treatment agent composition in the range of 0.1 to 5.0% by mass, the stability of the active ingredient is good.

[0036] In the water treatment agent composition, with respect to 5 - chloro - 2 - methyl - 4 - isothiazolin - 3 - one (CMI), which is an isothiazolin - based bactericide, the halogenated aliphatic nitroalcohol - based bactericide is contained in a mass ratio of 0.05 times or more, preferably 0.1 times or more, and more preferably 1.0 times or more. The upper limit of this mass ratio is not particularly limited, but is, for example, 5.0 times or less. When the content of the halogenated aliphatic nitroalcohol - based bactericide with respect to CMI is less than 0.1 times in mass ratio, the stabilizing effect of the active ingredient may not be obtained. When it exceeds 5.0 times, the manufacturing cost may increase.

[0037] The pH of the water treatment agent composition is, for example, less than 5.0, preferably 3.0 or less, more preferably in the range of 1.0 to 3.0, and even more preferably in the range of 1.5 to 2.5. When the pH of the composition is less than 1.0, a large amount of acid may be required. When it is 5.0 or more, the stabilizing effect of the active ingredient may not be obtained.

[0038] For adjusting the pH of the composition, it is only necessary to be able to adjust it to a predetermined pH, and there is no particular limitation. For example, pH adjusters such as acids such as hydrochloric acid, sulfuric acid, and nitric acid, and alkalis such as aqueous sodium hydroxide solution and aqueous potassium hydroxide solution may be used.

[0039] The water treatment composition may further contain a fluorescent substance as a tracer substance. By including a fluorescent substance in the water treatment composition, it is possible to easily measure the concentration of the water treatment composition in an aqueous system. Also, an effect of reducing the manufacturing cost can be obtained.

[0040] The fluorescent substance may be any chemical substance that absorbs a specific wavelength and emits a wavelength (fluorescence) different from that wavelength, and there is no particular limitation. Examples of the fluorescent substance include sulfonated pyrene compounds such as sodium 1,3,6,8-pyrenetetrasulfonate (PTSA), uranine, fluorescein, phycoerythrin, phycocyanin, rhodamine, and the like. Also, sulfonated benzonaphthofuran compounds, sulfonated dinaphthofuran compounds, sulfonated benzofluorene compounds, sulfonated dibenzofluorene compounds, sulfonated benzocarbazole compounds, sulfonated dibenzocarbazole compounds, etc. described in International Patent Application Publication No. 2023 / 210363 may be used. From the viewpoints of solubility and stability in the water treatment composition, it is preferable to use PTSA. The fluorescent substance may be used alone or in combination of two or more.

[0041] When the water treatment agent composition contains a fluorescent substance, the blending amount of the fluorescent substance is, for example, in the range of 0.0001 to 4.0% by mass, preferably in the range of 0.001 to 1.0% by mass, based on the total amount of the composition. If the blending amount of the fluorescent substance is less than 0.0001% by mass, it may be difficult to measure the concentration of the water treatment composition in an aqueous system, and if it exceeds 4.0% by mass, the manufacturing cost may increase.

[0042] In addition to water, an isothiazoline-based bactericide, a halogenated aliphatic nitroalcohol-based bactericide, the above polymer, and a fluorescent substance, the water treatment agent composition may further contain other components such as a corrosion inhibitor such as an azole compound and an oxidizing agent.

[0043] Examples of azole compounds mainly include azole compounds that function as metal corrosion inhibitors for copper-based metals such as copper and copper alloys. For example, 1,2,4-triazole, 1-methyl-1,2,4-triazole, 3-methyl-1,2,4-triazole, 3,5-dimethyl-1,2,4-triazole, 3,5-diethyl-1,2,4-triazole, 1-phenyl-1,2,4-triazole, 3-phenyl-1,2,4-triazole, 1,5-diphenyl-1,2,4-triazole, 1,3-diphenyl-1,2,4-triazole, 3,5-diphenyl-1,2,4-triazole, 1,2,4-triazole-3-one, 5-methyl-1,2,4-triazole-3-one, 3-methyl-1,2,4-triazole-5-one, 1-phenyl-1,2,4-triazole-3-one, 5-phenyl-1,2,4-triazole-3-one, 1-phenyl-1,2,4-triazole-5-one, urazole, 1-phenylurazole, 4-phenylurazole, benzotriazole, 1-methylbenzotriazole, 4-methylbenzotriazole, 5-methylbenzotriazole, 5,6-methylbenzotriazole, 2-phenylbenzotriazole, 1-hydroxybenzotriazole, 2-(3-t-butyl-5-methyl-2-hydroxyphenyl)-5-chlorobenzotriazole, 2-(5-methyl-2-hydroxyphenyl)benzotriazole, 2-(3,5-di-t-amyl-2-hydroxyphenyl)benzotriazole, 2-(3,5-di-t-butyl-2-hydroxyphenyl)-5-chlorobenzotriazole, 2-(3,5-di-t-butyl-2-hydroxyphenyl)benzotriazole, 2-(2'-hydroxy-5-octylphenyl)benzotriazole, 2-(2-hydroxy-4'-octoxyphenyl)benzotriazole, 2-(2-hydroxy-5-methylphenyl)benzotriazole, 2-(2'-hydroxy-5'-t-butylphenyl)benzotriazole, 2-(2'-hydroxy-3-t-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2-hydroxy-3,5-t-aminophenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-t-butyl)-5-chlorobenzotriazole, 2-(2-hydroxy-3,5-di-t-butylphenyl)benzotriazole, 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole, 1-naphthylbenzotriazole, 5-chlorobenzotriazole, 5-bromobenzotriazole, 5-nitrobenzotriazole, 4,5,6,7-tetrahydrobenzotriazole and the like can be mentioned. Among these, from the viewpoints of circulation volume and cost, benzotriazole, 4-methylbenzotriazole, and 5-methylbenzotriazole are preferable.,

[0044] In the water treatment agent composition, when an azole compound is contained, the blending amount of the azole compound is, for example, in the range of 0.001 to 3.0% by mass, preferably in the range of 0.1 to 2.0% by mass, based on the total amount of the composition. When the blending amount of the azole compound is less than 0.001% by mass, the corrosion inhibition effect may not be obtained, and when it exceeds 3.0% by mass, it may be difficult to dissolve in the water treatment agent composition.

[0045] <Water treatment method> The water treatment method according to the present embodiment is a method for treating an aqueous system using the above water treatment agent composition. For example, a predetermined amount of the above water treatment agent composition may be added to the aqueous system.

[0046] The amount of 5-chloro-2-methyl-4-isothiazolin-3-one, which is an isothiazolin-based bactericide in the aqueous system, may be, for example, in the range of 0.005 to 40 mg / L, preferably in the range of 0.1 to 25 mg / L, based on the amount of water to be treated. When the amount of the isothiazolin-based bactericide is less than 0.005 mg / L based on the amount of water to be treated, the bactericidal effect may not be obtained, and when it exceeds 40 mg / L, the amount of chemical used may increase.

[0047] The amount of the halogenated aliphatic nitroalcohol - based bactericide in the aqueous system may be, for example, in the range of 0.01 to 20 mg / L, preferably in the range of 0.1 to 10 mg / L, based on the amount of water to be treated. If the amount of the halogenated aliphatic nitroalcohol - based bactericide is less than 0.01 mg / L based on the amount of water to be treated, the bactericidal effect may not be obtained. If it exceeds 20 mg / L, the amount of chemical used may increase.

[0048] The pH of the aqueous system is, for example, in the range of 5.0 to 9.0, preferably in the range of 5.0 to 8.5, and more preferably in the range of 6.5 to 8.5. If the pH of the aqueous system is less than 5.0, corrosive gases may be generated. If it exceeds 9.0, scale may be generated.

[0049] For adjusting the pH of the aqueous system, any agent can be used as long as it can adjust the pH to a predetermined value, and there is no particular limitation. For example, pH adjusters such as acids like hydrochloric acid, sulfuric acid, nitric acid, and alkalis like aqueous sodium hydroxide solution, aqueous potassium hydroxide solution can be used.

[0050] The water treatment agent composition according to this embodiment can be used for water treatment of industrial water systems such as cooling water, and for the papermaking process water in the paper pulp industry. The water treatment agent composition according to this embodiment can be preferably used for water treatment of industrial water systems such as cooling water.

[0051] In the water treatment method according to this embodiment, other chemicals such as oxidants may be used in combination with the above - mentioned water treatment agent composition.

[0052] This specification includes the following embodiments. [1] It contains water, an isothiazoline - based bactericide, a halogenated aliphatic nitroalcohol - based bactericide, and a polymer containing at least the monomer unit of formula (1). The isothiazoline-based bactericide contains 5-chloro-2-methyl-4-isothiazolin-3-one, and the halogenated aliphatic nitroalcohol-based bactericide is contained in an amount of 0.05 times or more by mass with respect to the 5-chloro-2-methyl-4-isothiazolin-3-one, a water treatment agent composition. [Chemical formula] (In formula (1), R 1 represents a hydrogen atom or a methyl group, and X 1 represents a hydrogen atom, a monovalent or divalent metal atom, an ammonium group or an organic ammonium group.)

[0053] [2] Water, an isothiazoline-based bactericide, a halogenated aliphatic nitroalcohol-based bactericide, and a copolymer containing at least a monomer unit of formula (1) and a monomer unit of formula (2). The isothiazoline-based bactericide contains 5-chloro-2-methyl-4-isothiazolin-3-one, and the halogenated aliphatic nitroalcohol-based bactericide is contained in an amount of 0.05 times or more by mass with respect to the 5-chloro-2-methyl-4-isothiazolin-3-one, a water treatment agent composition. [Chemical formula] (In formula (1), R 1 represents a hydrogen atom or a methyl group, and X 1 represents a hydrogen atom, a monovalent or divalent metal atom, an ammonium group or an organic ammonium group.) [Chemical formula] (In formula (2), R 2 represents a hydrogen atom or a methyl group, and X 2 represents an alkylsulfonic acid group or a salt thereof, or an arylsulfonic acid group or a salt thereof, and in the case of a salt, it is a monovalent or divalent metal salt, an ammonium salt or an organic ammonium salt.)

[0054] [3] The water treatment agent composition according to [1] or [2], A water treatment agent composition containing 1.0 times or more of the halogenated aliphatic nitroalcohol - based bactericide by mass ratio with respect to the 5 - chloro - 2 - methyl - 4 - isothiazolin - 3 - one.

[0055] [4][1] The water treatment agent composition according to any one of [1] to [3], The water treatment agent composition having a pH of less than 5.0.

[0056] [5][1] The water treatment agent composition according to any one of [1] to [4], The water treatment agent composition, wherein the halogenated aliphatic nitroalcohol - based bactericide contains 2 - bromo - 2 - nitropropane - 1,3 - diol.

[0057] [6][1] The water treatment agent composition according to any one of [1] to [5], Further containing a fluorescent substance.

[0058] [7][1] A water treatment method for performing water - based treatment using the water treatment agent composition according to any one of [1] to [6].

Examples

[0059] Hereinafter, examples and comparative examples will be given to explain the present invention more specifically and in detail. However, the present invention is not limited to the following examples.

[0060] <Examples, Comparative Examples> For the examples and comparative examples, formulation was carried out by adding them to pure water in the blending compositions (mass %) shown in Tables 1 to 3 and in the order. For pH adjustment, sulfuric acid (62.5 mass %) was used, and for formulation, each chemical was added while stirring with a stirrer in a glass container at room temperature (25 °C ± 1 °C). The blending ratio of the polymer is calculated as the mass ratio of the solid content.

[0061] As isothiazoline-based bactericides, 5-chloro-2-methyl-4-isothiazolin-3-one (CMI) and 2-methyl-4-isothiazolin-3-one (MIT) were used.

[0062] As halogenated aliphatic nitroalcohol-based bactericides, 2-bromo-2-nitropropane-1,3-diol (BNPD) was used.

[0063] As the polymer, polyacrylic acid (PAA) (weight average molecular weight: 4500) was used. As the binary copolymer, a copolymer of acrylic acid and 2-acrylamido-2-methylpropanesulfonic acid (AA / AMPS) (weight average molecular weight: 4500) was used. As the terpolymer, a copolymer of acrylic acid, 2-acrylamido-2-methylpropanesulfonic acid, and t-butylacrylamide (AA / AMPS / t-BAM) (weight average molecular weight: 4500) was used.

[0064] As the azole compound, benzotriazole was used.

[0065] As the fluorescent substance, sodium 1,3,6,8-pyrenetetrasulfonate (PTSA) was used.

[0066] The pH of the formulated preparation was measured using a pH measuring device (manufactured by Toa DKK Corporation, IOL-30). The feasibility of formulation was determined by visual observation of the appearance after storage at 50 °C for 20 days (Tables 1 and 3) or 7 days (Table 2), and those with precipitation were judged as "×". For the compositions in Table 3, the residual ratio (%) of the active ingredient was measured and judged according to the following criteria. The residual ratio of the active ingredient in the compositions in Table 3 is the data after storage at 50 °C for 20 days. The results are shown in Tables 1 to 3.

[0067] The residual ratio of the active ingredient was calculated based on the area value measured by the high-performance liquid chromatograph Chromaster of Hitachi High-Technologies Corporation using an analytical column of Tosoh Corporation (manufactured by Tosoh, TSKgel ODS-80Ts).

[0068] (Determination Criteria (Residual Rate of Active Ingredient (%))) ◎: Over 90% to 100% 〇: Over 80% to 90% or less △: Over 70% to 80% or less ×: 70% or less

[0069]

Table 1

[0070]

Table 2

[0071]

Table 3

[0072] The composition of the example contains at least a polymer containing the monomer unit of formula (1) or a copolymer containing at least the monomer unit of formula (1) and the monomer unit of formula (2). Compared with the composition of the comparative example, no precipitation was observed after storage at 50°C for 20 days or 7 days, and it was found that the residual rate of the active ingredient was high.

[0073] Thus, in the composition of the example, the stability of the active ingredient was good in the water treatment agent composition containing water, an isothiazoline-based bactericide, and a halogenated aliphatic nitroalcohol-based bactericide.

Claims

1. A water treatment agent composition containing water, an isothiazoline-based bactericide, a halogenated aliphatic nitroalcohol-based bactericide, and a polymer containing at least a monomer unit of formula (1). The isothiazoline-based bactericide contains 5-chloro-2-methyl-4-isothiazolin-3-one, and the halogenated aliphatic nitroalcohol-based bactericide is contained in a mass ratio of 0.05 times or more with respect to the 5-chloro-2-methyl-4-isothiazolin-3-one. 【Chemical 1】 (In formula (1), R １ represents a hydrogen atom or a methyl group, and X １ represents a hydrogen atom, a monovalent or divalent metal atom, an ammonium group, or an organic ammonium group.)

2. A water treatment agent composition containing water, an isothiazoline-based bactericide, a halogenated aliphatic nitroalcohol-based bactericide, and a copolymer containing at least a monomer unit of formula (1) and a monomer unit of formula (2). The isothiazoline-based bactericide contains 5-chloro-2-methyl-4-isothiazolin-3-one, and the halogenated aliphatic nitroalcohol-based bactericide is contained in a mass ratio of 0.05 times or more with respect to the 5-chloro-2-methyl-4-isothiazolin-3-one. [Chemical Formula 2] (In formula (1), R １ represents a hydrogen atom or a methyl group, and X １ represents a hydrogen atom, a monovalent or divalent metal atom, an ammonium group, or an organic ammonium group.) [Chemical 3] (In formula (2), R ２ represents a hydrogen atom or a methyl group, and X ２ represents an alkylsulfonic acid group or a salt thereof, or an arylsulfonic acid group or a salt thereof. In the case of a salt, it is a monovalent or divalent metal salt, an ammonium salt, or an organic ammonium salt.)

3. The water treatment agent composition according to claim 1 or 2, wherein the halogenated aliphatic nitroalcohol-based bactericide is contained in a mass ratio of 1.0 times or more with respect to the 5-chloro-2-methyl-4-isothiazolin-3-one.

4. The water treatment agent composition according to claim 1 or 2, wherein the pH of the water treatment agent composition is less than 5.

0.

5. The water treatment agent composition according to claim 1 or 2, wherein the halogenated aliphatic nitroalcohol-based bactericide contains 2-bromo-2-nitropropane-1,3-diol.

6. The water treatment agent composition according to claim 1 or 2, further comprising a fluorescent substance.

7. A water treatment method characterized by performing treatment of an aqueous system using the water treatment agent composition according to claim 1 or 2.

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