TW202031602A - Cooling water scale prevention agent and cooling water scale prevention method - Google Patents

Abstract

A cooling water scale prevention agent for a cooling water system that contains iron, manganese, and/or aluminum. The cooling water scale prevention agent includes a component (A) and a component (B). Component (A) is one or more compound selected from among: copolymers, and salts thereof, that include a structural unit that is derived from acrylic acid and a structural unit that is derived from 2-acrylamido-2-methylpropane sulfonic acid; and copolymers, and salts thereof, that include a structural unit that is derived from acrylic acid and a structural unit that is derived from 2-hydroxy-3-allyloxypropane sulfonic acid. Component (B) is one or more compound selected from among: ethylenediaminetetraacetic acid and salts thereof; tetrasodium 3-hydroxy-2,2-iminodisuccinic acid and salts thereof; [(phosphonomethyl)imino]bis(6,1-hexanediylnitrilobismethylene)tetrakisphosphonic acid and salts thereof; and 1-hydroxyethane-1,1-diphosphonic acid and salts thereof.

Description

Scale inhibitor for cooling water and method for scale inhibition for cooling water

The present invention relates to a scale inhibitor for cooling water and a method for preventing scale generated in a cooling water system containing one or more selected from iron, manganese and aluminum.

In an open-circulation cooling water system, there is a situation where, in the case of a high concentration operation to reduce the discharge of cooling water to the outside of the system (blow), the dissolved salts are concentrated to become insoluble salts, thereby forming scale. Such scales may cause important obstacles to the operation of the heat exchanger, such as a decrease in thermal efficiency and clogging of piping.

For calcium-based scale, which is a kind of scale, it is useful to polymerize maleic acid, acrylic acid, itaconic acid, etc., to polymer having a carboxyl group, and acrylic acid and 2-propenamide-2-methylpropane Sulfonic acid copolymer (hereinafter also referred to as "AA/AMPS copolymer"), or acrylic acid and 2-hydroxy-3-allyloxypropanesulfonic acid copolymer (hereinafter also referred to as "AA/HAPS copolymer" )) Copolymers combined with nonionic vinyl monomers according to the target water quality are generally used as scale adhesion inhibitors. For example, Patent Document 1 discloses a scale prevention method using an AA/AMPS copolymer. In addition, Patent Document 2 discloses a treatment method of a cooling water system using an AA/HAPS copolymer. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. Sho 50-86489 [Patent Document 2] Japanese Patent Laid-Open No. 2013-212435

[The problem to be solved by the invention] However, in the cooling water system of iron, manganese, aluminum, etc., there is a problem that the scale preventing effect of these copolymers is reduced. In addition, for the purpose of preventing silica-based scale or improving the effect of preventing scale on cooling water systems where iron is present, acrylic acid and 2-propenamide-2-methylpropanesulfonic acid are used as nonionic monomers. And tertiary butyl acrylamide copolymer (hereinafter also referred to as "AA/AMPS/t-BuAAM copolymer") is used as a scale adhesion preventive agent. Although this situation has been studied, iron, manganese and aluminum are present. In a cooling water system such as this, even such a scale adhesion inhibitor has a problem that the scale prevention effect is reduced. In order to improve the scale prevention effect in such a cooling water system, efforts are being made to increase the addition amount of the copolymer as a scale inhibitor, but there are cases where the scale prevention effect is insufficient. In addition, even if the effect is improved, the cost of water treatment may not match, and an efficient and economical method for preventing scale precipitation is desired.

The present invention is made in view of the above-mentioned actual situation, and its subject is to provide a cooling water system such as an open circulating cooling water system containing one or more selected from iron, manganese, and aluminum to prevent scale from adhering to carbon steel or copper, Metallic equipment such as copper alloys, piping, equipment, etc., as well as scale inhibitors for cooling water and methods for cooling water that accompany scale obstacles. [Means to solve the problem]

The present invention is based on the discovery that excellent scale prevention can be obtained by using a cooling water scale inhibitor containing a specific copolymer and compound in a cooling water system containing one or more selected from iron, manganese and aluminum effect.

That is, the present invention provides the following [1] to [13]. [1] A scale inhibitor for cooling water, which is a scale inhibitor for cooling water containing one or more kinds of cooling water systems selected from iron, manganese and aluminum, and comprising component (A) and component (B), The component (A) is selected from copolymers containing structural units derived from acrylic acid and structural units derived from 2-propenamide-2-methylpropanesulfonic acid and salts thereof, and structural units derived from acrylic acid One or more compounds in copolymers and their salts with structural units derived from 2-hydroxy-3-allyloxypropanesulfonic acid, The component (B) is selected from the group consisting of ethylenediaminetetraacetic acid and its salts, 3-hydroxy-2,2'-imino disuccinic acid tetrasodium and its salts, [(phosphinomethyl)imino ] One or more compounds of bis(6,1-hexanediylazobismethylene)tetraphosphonic acid and its salts, and 1-hydroxyethane-1,1-diphosphonic acid and its salts. [2] The scale inhibitor for cooling water as described in [1], wherein the copolymerization of the structural unit derived from acrylic acid and the structural unit derived from 2-propenamide-2-methylpropanesulfonic acid And its salts are selected from copolymers of acrylic acid and 2-propenamide-2-methylpropanesulfonic acid and their salts, and acrylic acid, 2-propenamide-2-methylpropanesulfonic acid and tertiary butyl One or more compounds of acrylamide copolymers and their salts. [3] The scale inhibitor for cooling water as described in [1] or [2], which contains a structural unit derived from acrylic acid and a structural unit derived from 2-hydroxy-3-allyloxypropanesulfonic acid The copolymer and its salt are the copolymer of acrylic acid and 2-hydroxy-3-allyloxypropanesulfonic acid and its salt. [4] The scale inhibitor for cooling water according to any one of [1] to [3], wherein the cooling water system contains 0.5 mg/L or more and 5.0 mg/L or less selected from iron, One or more of manganese and aluminum. [5] The scale inhibitor for cooling water according to any one of [1] to [4], wherein the mass ratio of the component (A) to the component (B1) is 98:2 to 13:87 The component (B1) is one or more compounds selected from ethylenediaminetetraacetic acid and its salts, and 3-hydroxy-2,2'-iminodisuccinate tetrasodium and its salts. [6] The scale inhibitor for cooling water described in any one of [1] to [4], wherein the mass ratio of the component (A) to the component (B2) is 98:2 to 38:62 , The component (B2) is selected from [(phosphinomethyl)imino]bis(6,1-hexanediylnitrobismethylene)tetraphosphonic acid and its salts, and 1-hydroxyl One or more compounds of ethane-1,1-diphosphonic acid and its salts. [7] A scale inhibition method for cooling water, which is a scale inhibition method for cooling water containing one or more kinds of cooling water systems selected from iron, manganese, and aluminum, and using a method containing component (A) and component (B) Scale inhibitor for cooling water, The component (A) is selected from copolymers containing structural units derived from acrylic acid and structural units derived from 2-propenamide-2-methylpropanesulfonic acid and salts thereof, structural units derived from acrylic acid and One or more compounds of copolymers derived from structural units of 2-hydroxy-3-allyloxypropanesulfonic acid and their salts, The component (B) is selected from the group consisting of ethylenediaminetetraacetic acid and its salts, 3-hydroxy-2,2'-imino disuccinic acid tetrasodium and its salts, [(phosphinomethyl)imino ] One or more compounds of bis(6,1-hexanediylazobismethylene)tetraphosphonic acid and its salts, and 1-hydroxyethane-1,1-diphosphonic acid and its salts. [8] The method for scale inhibition for cooling water as described in [7], wherein the copolymerization of a structural unit derived from acrylic acid and a structural unit derived from 2-propenamide-2-methylpropanesulfonic acid And its salts are selected from copolymers of acrylic acid and 2-propenamide-2-methylpropanesulfonic acid and their salts, and acrylic acid, 2-propenamide-2-methylpropanesulfonic acid and tertiary butyl One or more of acrylamide copolymers and their salts. [9] The method for scale inhibition for cooling water as described in [7] or [8], wherein the structural unit derived from acrylic acid and the compound derived from 2-hydroxy-3-allyloxypropanesulfonic acid The copolymers of structural units and their salts are copolymers of acrylic acid and 2-hydroxy-3-allyloxypropanesulfonic acid and their salts. [10] The scale inhibition method for cooling water as described in any one of [7] to [9], wherein the cooling water system contains 0.5 mg/L or more and 5.0 mg/L or less selected from iron, One or more of manganese and aluminum. [11] The scale inhibition method for cooling water as described in any one of [7] to [10], wherein the concentration of the component (A) in the cooling water system is 3.0 mg/L Add the ingredient (A) above and below 20.0 mg/L. [12] The scale inhibition method for cooling water as described in any one of [7] to [11], wherein the concentration of the component (B1) in the cooling water system is 0.5 mg/L or more, The component (B1) is added in a manner of 20.0 mg/L or less, and the component (B1) is selected from ethylenediaminetetraacetic acid and its salts, and 3-hydroxy-2,2'-iminodisuccinic acid One or more compounds of sodium and its salts. [13] The scale inhibition method for cooling water as described in any one of [7] to [11], wherein the concentration of the component (B2) in the cooling water system is 0.5 mg/L or more, Add the component (B2) at a rate of 5.0 mg/L or less, and the component (B2) is selected from [(phosphinomethyl)imino]bis(6,1-hexanediylazabiylidene) (Methyl)tetraphosphonic acid and its salts, and 1-hydroxyethane-1,1-diphosphonic acid and its salts are one or more compounds. [Effects of the invention]

According to the present invention, it is possible to effectively prevent scale adhesion to metallic equipment or pipes such as carbon steel, copper, and copper alloys in cooling water systems such as open circulating cooling water systems containing one or more selected from iron, manganese, and aluminum , Machines, etc. In addition, it is also possible to prevent scale obstacles accompanying the adhesion of scale. Therefore, the scale inhibitor for cooling water and the scale inhibitor method for cooling water of the present invention can contribute to stable and safe operation of the cooling water system and reduction in energy cost.

Hereinafter, the scale inhibitor for cooling water of the present invention and the scale inhibitor method for cooling water using the same will be described in detail.

[Scaling inhibitor for cooling water] The scale inhibitor for cooling water of the present invention is a scale inhibitor for cooling water containing one or more kinds of cooling water systems selected from iron, manganese, and aluminum, and includes component (A) and component (B), and the component ( A) is selected from copolymers containing structural units derived from acrylic acid and structural units derived from 2-propenamide-2-methylpropanesulfonic acid and their salts, and structural units derived from acrylic acid and derived from 2 -Hydroxy-3-allyloxypropanesulfonic acid copolymer of structural units and one or more of its salts, the component (B) is selected from ethylenediaminetetraacetic acid and its salts, 3-hydroxy- 2,2'-imino disuccinic acid tetrasodium and its salt, [(phosphorinylmethyl)imino]bis(6,1-hexanediylnitrobismethylene)tetraphosphonic acid and One or more compounds of its salt, 1-hydroxyethane-1,1-diphosphonic acid and its salt. The scale inhibitor for cooling water of the present invention has the above-mentioned two components (A) and component (B) as essential components, and can exhibit an excellent scale preventing effect in a cooling water system.

The scale inhibitor may be obtained by pre-preparing the mixed component (A) and component (B), or may be one in which each component is added separately during use. From the viewpoint of ease of handling or viscosity, the total content of the component (A) and the component (B) in the scale inhibitor prepared and mixed in advance is preferably 0.001% by mass or more and 1.000% by mass or less, and more preferably It is 0.010% by mass or more and 0.500% by mass or less. In addition, the total content of component (A) and component (B) in the effective ingredients in the scale inhibitor prepared and mixed in advance is preferably 80.0% by mass or more, more preferably 90.0% by mass or more, and still more preferably 95.0% by mass % Or more, particularly preferably 100% by mass. When each component is added separately at the time of use, the content of component (A) in a scale inhibitor containing component (A) and not containing component (B) is preferable in terms of ease of handling or viscosity It is 0.001 mass% or more and 1.000 mass% or less, more preferably 0.010 mass% or more and 0.500 mass% or less, and still more preferably 0.020 mass% or more and 0.100 mass% or less. In addition, the content of the component (A) in the active ingredient in the scale inhibitor containing the component (A) and not containing the component (B) is preferably 80.0% by mass or more, more preferably 90.0% by mass or more, and still more preferably 95.0 Mass% or more, particularly preferably 100% by mass. When each component is added separately at the time of use, the content of component (B) in a scale inhibitor containing component (B) and not containing component (A) is preferable from the viewpoint of ease of handling or viscosity It is 0.001 mass% or more and 1.000 mass% or less, more preferably 0.010 mass% or more and 0.500 mass% or less, and still more preferably 0.020 mass% or more and 0.100 mass% or less. In addition, the content of the component (B) in the active ingredient in the scale inhibitor containing the component (B) and not containing the component (A) is preferably 80.0% by mass or more, more preferably 90.0% by mass or more, and still more preferably 95.0 Mass% or more, particularly preferably 100% by mass.

The scale inhibitor for cooling water of the present invention can be applied to a cooling water system containing one or more selected from iron, manganese and aluminum. If the concentration of one or more selected from iron, manganese and aluminum in the cooling water is 0.1 mg/L or more and 12.0 mg/L or less, the effect of the scale inhibitor for cooling water can be more prominently exhibited, but if it is better 0.3 mg/L or more, 10.0 mg/L or less, more preferably 0.4 mg/L or more, 7.0 mg/L or less, further preferably 0.5 mg/L or more, 5.0 mg/L or less, particularly preferably 0.5 mg/L or more , 4.0 mg/L or less, can play a more excellent effect. In addition, the concentration of iron, manganese, and aluminum is a value measured by a method such as an atomic absorption method or a thiocyanate method (absorbance method).

(Component (A)) Component (A) is selected from copolymers containing structural units derived from acrylic acid (AA) and structural units derived from 2-propenamide-2-methylpropanesulfonic acid (AMPS) and their salts, and containing One or more compounds of copolymers of structural units of acrylic acid (AA) and structural units derived from 2-hydroxy-3-allyloxypropanesulfonic acid (HAPS) and their salts, and function as a scale dispersant . These copolymers may be used alone or in combination of two or more.

The copolymer containing a structural unit derived from acrylic acid and a structural unit derived from 2-propenamide-2-methylpropanesulfonic acid and its salt may be a copolymer containing only acrylic acid (AA) and 2-propenamide-2-methyl The copolymer of propyl propane sulfonic acid (AMPS) and its salt, as long as it does not interfere with the purpose and effects of the present invention, may have acrylic acid (AA) and 2-propenamide-2-methyl propane sulfonic acid ( Copolymers of structural units of monomers other than AMPS) and their salts.

A salt containing a copolymer of a structural unit derived from acrylic acid and a structural unit derived from 2-propenamide-2-methylpropanesulfonic acid can be, for example, combined with a structural unit derived from acrylic acid and a copolymer derived from 2-acrylic acid. It is obtained by neutralizing the copolymer of the structural unit of amine-2-methylpropanesulfonic acid. In addition, acrylic acid (AA), 2-propenamide-2-methylpropanesulfonic acid (AMPS) and other monomers as necessary can also be neutralized as raw material monomers to produce acrylate, 2-acrylic acid. Amine-2-methylpropanesulfonate and optionally other monomer salts are obtained by copolymerizing the salts. The salt of a copolymer containing a structural unit derived from acrylic acid and a structural unit derived from 2-propenamide-2-methylpropanesulfonic acid obtained in the manner described is not limited to the completely neutralized product of the copolymer, and It can be partially neutralized. Specific examples of the salt containing a copolymer of a structural unit derived from acrylic acid and a structural unit derived from 2-propenamide-2-methylpropanesulfonic acid include a structural unit derived from acrylic acid and a salt derived from 2-propenamide-2-methylpropanesulfonic acid. Alkali metal salt, ammonium salt, amine salt, etc. of the copolymer of the structural unit of acrylamide-2-methylpropanesulfonic acid. With regard to these salts, suitable salts can be appropriately selected and used according to the cooling water system using the scale inhibitor.

The copolymer containing a structural unit derived from acrylic acid and a structural unit derived from 2-propenamide-2-methylpropanesulfonic acid and its salt are preferably acrylic acid (AA) and 2-propenamide-2-methyl Propanesulfonic acid (AMPS) copolymer (hereinafter also referred to as "AA/AMPS copolymer") and its salt, acrylic acid (AA), 2-propenamide-2-methylpropanesulfonic acid (AMPS), Copolymer of tributyl acrylamide (t-BuAAM) (hereinafter also referred to as "AA/AMPS/t-BuAAM copolymer" and its salt, and more preferably AA/AMPS copolymer and AA/AMPS/t-BuAAM Copolymer.

The weight average molecular weight of the AA/AMPS copolymer and its salt is preferably 1,000 to 200,000, more preferably 2,000 to 80,000, still more preferably 5,000 to 75,000, particularly preferably 10,000 to 50,000. If the weight average molecular weight is within the above range, a good dispersion effect for scale can be obtained. Furthermore, the weight average molecular weight, the weight average molecular weight of the AA/HAPS copolymer and its salt described later, and the AA/AMPS/t-BuAAM copolymer and its salt are based on Gel Permeation Chromatography (Gel Permeation Chromatography, GPC) The weight average molecular weight calculated in terms of standard polystyrene. From the viewpoint of the scale dispersion effect, the molar ratio of the structural unit derived from AA and its salt constituting the AA/AMPS copolymer and its salt to the structural unit derived from AMPS and its salt is preferably 99:1 to 5: 95, more preferably 95:5-50:50, still more preferably 90:10-70:30.

The weight average molecular weight of the AA/AMPS/t-BuAAM copolymer and its salt is preferably 3,000 to 12,000, more preferably 3,000 to 10,000, and still more preferably 4,000 to 7,000. If the weight average molecular weight is within the above range, a good dispersion effect for scale can be obtained. From the viewpoint of the scale dispersion effect, the content of the structural unit derived from AA and its salt in all the structural units of the AA/AMPS/t-BuAAM copolymer and its salt is preferably 10 mol% to 90 mol% , More preferably 40 mol% to 85 mol%, and still more preferably 70 mol% to 80 mol%. From the viewpoint of the scale dispersion effect, the content of the structural unit derived from AMPS and its salt in all the structural units of the AA/AMPS/t-BuAAM copolymer and its salt is preferably 5 mol% to 40 mol% , More preferably 7 mol%-20 mol%, further preferably 10 mol%-15 mol%. From the viewpoint of the scale dispersion effect, the content of structural units derived from t-BuAAM in all structural units of the AA/AMPS/t-BuAAM copolymer and its salts is preferably 5 mol% to 50 mol%, It is more preferably 7 mol% to 20 mol%, and still more preferably 10 mol% to 15 mol%.

In the case where the copolymer and its salt containing a structural unit derived from acrylic acid and a structural unit derived from 2-propenamide-2-methylpropanesulfonic acid have structural units derived from other monomers, based on the The total mass of the copolymer of the structural unit of acrylic acid and the structural unit derived from 2-propenamide-2-methylpropanesulfonic acid and its salt, and the content of the structural unit derived from other monomers is preferably 50% by mass or less , More preferably 30% by mass or less, and still more preferably 20% by mass or less.

Examples of the other monomers include: carboxylic acids, monoethylenically unsaturated hydrocarbons, alkyl esters of monoethylenically unsaturated acids, vinyl esters of monoethylenically unsaturated acids, substituted acrylamides, and N-ethylene One or two or more of the group monomer, the hydroxyl-containing unsaturated monomer, (meth)acrylate, the aromatic unsaturated monomer, and the sulfonic acid.

The copolymer and its salt containing a structural unit derived from acrylic acid and a structural unit derived from 2-hydroxy-3-allyloxypropanesulfonic acid may contain only acrylic acid (AA) and 2-hydroxy-3-allyloxy The copolymer of HAPS and its salt, as long as it does not interfere with the purpose and effects of the present invention, may have acrylic acid (AA) and 2-hydroxy-3-allyloxypropane sulfonic acid ( Copolymers of structural units of monomers other than HAPS) and their salts.

A salt containing a copolymer of a structural unit derived from acrylic acid and a structural unit derived from 2-hydroxy-3-allyloxypropanesulfonic acid can be, for example, combined with a structural unit derived from acrylic acid and a 2-hydroxy-derived salt. It is obtained by neutralizing the copolymer of the structural unit of 3-allyloxypropanesulfonic acid. In addition, acrylic acid (AA), 2-hydroxy-3-allyloxypropanesulfonic acid (HAPS) and other monomers as necessary can also be neutralized as raw material monomers to produce acrylate, 2-hydroxy- The salt of 3-allyloxypropane sulfonate and other monomers as necessary is obtained by copolymerizing the salt. The salt of the copolymer containing the structural unit derived from acrylic acid and the structural unit derived from 2-hydroxy-3-allyloxypropanesulfonic acid obtained in the manner is not limited to the salt containing the structural unit derived from acrylic acid and The completely neutralized product of the copolymer of the structural unit of 2-hydroxy-3-allyloxypropanesulfonic acid may also be a partially neutralized product. As a specific example of a salt containing a copolymer of a structural unit derived from acrylic acid and a structural unit derived from 2-hydroxy-3-allyloxypropanesulfonic acid, a structural unit derived from acrylic acid and a salt derived from 2-hydroxy-3-allyloxypropanesulfonic acid are included. Alkali metal salt, ammonium salt, amine salt, etc. of the copolymer of the structural unit of hydroxy-3-allyloxypropanesulfonic acid. With regard to these salts, suitable salts can be appropriately selected and used according to the cooling water system using the scale inhibitor.

The copolymer containing a structural unit derived from acrylic acid and a structural unit derived from 2-hydroxy-3-allyloxypropanesulfonic acid and its salt are preferably acrylic acid (AA) and 2-hydroxy-3-allyloxy A copolymer of propylene sulfonic acid (HAPS) (hereinafter also referred to as "AA/HAPS copolymer") and its salt, and more preferably an AA/HAPS copolymer.

The weight average molecular weight of the AA/HAPS copolymer and its salt is preferably 1,000 to 20,000, more preferably 2,000 to 80,000, still more preferably 5,000 to 75,000, most preferably 10,000 to 50,000. If the weight average molecular weight is within the above range, a good dispersion effect for scale can be obtained. From the viewpoint of the scale dispersion effect, the molar ratio of the structural unit derived from AA and its salt constituting the AA/HAPS copolymer and its salt to the structural unit derived from HAPS and its salt is preferably 99:1 to 5: 95, more preferably 95:5-50:50, still more preferably 90:10-70:30.

In the case of copolymers containing structural units derived from acrylic acid and structural units derived from 2-hydroxy-3-allyloxypropanesulfonic acid and their salts having structural units derived from other monomers, based on the The total mass of the copolymer of the structural unit of acrylic acid and the structural unit derived from 2-hydroxy-3-allyloxypropanesulfonic acid and its salt, and the content of the structural unit derived from other monomers is preferably 50% by mass or less , More preferably 30% by mass or less, and still more preferably 20% by mass or less.

Examples of the other monomers include carboxylic acids, monoethylenically unsaturated hydrocarbons, alkyl esters of monoethylenically unsaturated acids, vinyl esters of monoethylenically unsaturated acids, substituted acrylamides, and N-vinyl groups. One or two or more of monomer, hydroxyl-containing unsaturated monomer, (meth)acrylate, aromatic unsaturated monomer, and sulfonic acid.

(Component (B)) Component (B) is selected from ethylenediaminetetraacetic acid (hereinafter also referred to as "EDTA") and its salts (hereinafter also referred to as "EDTA salt"), 3-hydroxy-2,2'-imino disuccinic acid Tetrasodium (hereinafter also referred to as "HIDS") and its salts (hereinafter also referred to as "HIDS salt"), [(phosphinomethyl)imino]bis(6,1-hexanediylnitrobis Methylene)tetraphosphonic acid (hereinafter also referred to as "BHMTPMP") and its salts (hereinafter also referred to as "BHMTPMP salt"), and 1-hydroxyethane-1,1-diphosphonic acid (hereinafter also referred to as " HEDP") and its salts (hereinafter also referred to as "HEDP salt") at least one compound. The scale inhibitor for cooling water of the present invention contains the component (B) in addition to the component (A), thereby exhibiting an excellent scale preventing effect. The reason is not certain, but it is believed that metal ions such as iron, manganese, and aluminum ions present in the cooling water are blocked by chelating agents and phosphonic acid to effectively inhibit the precipitation of scale.

Component (B) can be classified into chelating agent (component (B1)) and phosphonic acid (component (B2)). A chelating agent and phosphonic acid may be used alone, or a chelating agent and phosphonic acid may be used in combination.

Component (B1) is selected from ethylenediaminetetraacetic acid (EDTA) and its salt (EDTA salt), and 3-hydroxy-2,2'-imino disuccinic acid tetrasodium (HIDS) and its salt (HIDS salt) ) More than one compound. These chelating agent components (B1) may be used alone or in combination of two or more kinds. Component (B2) is selected from [(phosphinomethyl)imino]bis(6,1-hexanediylnitrobismethylene)tetraphosphonic acid (BHMTPMP) and its salts (BHMTPMP salt), And one or more compounds of 1-hydroxyethane-1,1-diphosphonic acid (HEDP) and its salts (HEDP salt). These phosphonic acid components (B2) may be used alone or in combination of two or more.

From the viewpoint of obtaining a good scale prevention effect, the quality of the component (A) and the component (B) in the scale inhibitor for cooling water is preferably 98:2-13:87, and more preferably 94:6-30 : 70, more preferably 90:10 to 40:60.

From the viewpoint of obtaining a good scale prevention effect, the quality ratio of component (A) and component (B1) in the scale inhibitor for cooling water is preferably 98:2-13:87, more preferably 94:6-30 : 70, more preferably 90:10 to 40:60. In addition, from the viewpoint of obtaining a good scale prevention effect, the quality ratio of component (A) and component (B2) in the scale inhibitor for cooling water is preferably 98:2-13:87, and more preferably 98:2 ~38:62, more preferably 94:6 to 60:40, particularly preferably 90:10 to 80:20.

Regarding the scale inhibitor, if it is within a range that does not impair the effect of the present invention, in addition to component (A) and component (B), it may be added to existing scale inhibitors such as alkali, deoxidizer, and corrosion inhibitor as needed The additives used, or other chelating agents and other phosphonic acids. Examples of other chelating agents include: trans-1,2-diaminocyclohexanetetraacetic acid (CyDTA), o,o'-bis(2-aminoethyl)ethylene glycol tetraacetic acid (GEDTA), Diethylenetriaminepentaacetic acid (DTPA), triethylenetetraaminehexaacetic acid (TTHA), nitrotriacetic acid (NTA), acetone and glycine etc. Examples of other phosphonic acids include: 2-phosphoranylbutane-1,2,3-tricarboxylic acid (PBTC), amino trimethylene phosphonic acid (ATMP), ethylenediamine tetramethylene phosphonic acid ( EDTMP), hydroxyethylene diphosphonic acid (HEDP) and nitrogen trimethylene phosphonic acid (NTMP), etc.

[Scaling inhibition method for cooling water] The scale inhibition method for cooling water of the present invention is a scale prevention method for a cooling water system containing one or more selected from iron, manganese, and aluminum, and uses a scale inhibition method for cooling water containing components (A) and (B) The method of preparation, the component (A) is selected from copolymers containing structural units derived from acrylic acid and structural units derived from 2-propenamide-2-methylpropanesulfonic acid and their salts, containing acrylic acid-derived The copolymer of the structural unit and the structural unit derived from 2-hydroxy-3-allyloxypropanesulfonic acid and one or more of its salts, the component (B) is selected from ethylenediaminetetraacetic acid and Its salt, 3-hydroxy-2,2'-imino disuccinic acid tetrasodium and its salt, [(phosphinomethyl) imino] bis (6,1-hexanediyl nitrogen bis (Methyl)tetraphosphonic acid and its salts, and 1-hydroxyethane-1,1-diphosphonic acid and its salts are one or more compounds. As long as it includes the step of adding the scale inhibitor, it may include other steps performed in the usual water system treatment. The method of adding the scale inhibitor is not particularly limited. For example, it may be prepared by adding the mixed component (A) and the component (B) in advance, or each component may be added independently.

The scale inhibition method for cooling water of the present invention can be applied to a cooling water system containing more than one selected from iron, manganese and aluminum. In the scale inhibition method for cooling water of the present invention, if the concentration of one or more selected from iron, manganese, and aluminum in the cooling water is 0.1 mg/L or more and 12.0 mg/L or less, the effect of inhibiting scale can be exerted. If it is preferably 0.3 mg/L or more, 10.0 mg/L or less, more preferably 0.4 mg/L or more, 7.0 mg/L or less, further preferably 0.5 mg/L or more, 5.0 mg/L or less, particularly preferably 0.5 mg/L or more and 4.0 mg/L or less can exert a more excellent scale inhibitory effect. In addition, the cooling water system of the scale prevention method of the present invention is preferably a circulating water system.

Regarding the concentration of the component (A) in the cooling water system, from the viewpoint of sufficiently obtaining the scale prevention effect, it is preferable to add the component (A) so that it becomes 3.0 mg/L or more and 20.0 mg/L or less, and more preferably In order to add the component (A) so that it becomes 4.0 mg/L or more and 15.0 mg/L or less, it is more preferable to add the component (A) so that it becomes 5.0 mg/L or more and 10.0 mg/L or less. If it is the said range, precipitation of scale can be prevented efficiently and economically.

Regarding the concentration of the component (B1) in the cooling water system, from the viewpoint of sufficiently obtaining the scale prevention effect, it is preferable to add the component (B1) so that it becomes 0.5 mg/L or more and 20.0 mg/L or less, and more preferably In order to add the component (B1) so that it becomes 0.7 mg/L or more and 15.0 mg/L or less, it is more preferable to add the component (B1) so that it becomes 0.8 mg/L or more and 12.0 mg/L or less. If it is the said range, precipitation of scale can be prevented efficiently and economically.

Regarding the concentration of the component (B2) in the cooling water system, from the viewpoint of sufficiently obtaining the scale prevention effect, it is preferable to add the component (B2) so that it becomes 0.5 mg/L or more and 5.0 mg/L or less, and more preferably In order to add the component (B2) so that it becomes 0.7 mg/L or more and 4.0 mg/L or less, it is more preferable to add the component (B2) so that it becomes 0.8 mg/L or more and 3.0 mg/L or less. If it is the said range, precipitation of scale can be prevented efficiently and economically.

From the viewpoint of obtaining a good scale prevention effect, the quality ratio of component (A) and component (B1) in the circulating water circulating in the cooling water system is preferably 98:2-13:87, and more preferably 94:6 ~30:70, more preferably 90:10-40:60. In addition, from the viewpoint of obtaining a good scale prevention effect, the quality ratio of the component (A) and the component (B2) in the circulating water circulating in the cooling water system is preferably 98:2-13:87, and more preferably 98 : 2 to 38:62, more preferably 94:6 to 60:40, particularly preferably 90:10 to 80:20.

In the scale prevention method, for example, the concentration of iron, manganese, and aluminum in the cooling water is detected, and the addition amount of the scale inhibitor relative to the cooling water is automatically controlled based on the concentration, so that the scale can be used safely and continuously Prevent effect. [Example]

Next, the present invention will be explained in more detail with examples, but the present invention is not limited by these examples.

[Preparation of treatment solution] (Acid consumption solution) To 13.78 g of sodium bicarbonate was added ultrapure water to make 1000 mL, mixed and stirred, and then adjusted to pH 8.3 with 0.1 N sodium hydroxide aqueous solution. An acid consumption solution with an acid consumption of 8200 mgCaCO ₃ /L. (Calcium ion solution) Add ultrapure water to 14.7 g of calcium chloride dihydrate to make 1000 mL, mix and stir, use 0.1 N sodium hydroxide aqueous solution to adjust the pH to 8.5, thereby making the calcium hardness 10000 mgCaCO ₃ /L calcium ion solution. (Phosphate ion solution) Add ultrapure water to 0.6729 g of sodium hydrogen phosphate to make 1000 mL. After mixing and stirring, adjust the pH to 8.5 with a 0.1 N sodium hydroxide aqueous solution to make the phosphate ion concentration 450 mg/L phosphate ion solution.

(Component (A) aqueous solution) All of the component (A) aqueous solutions used commercially available products with a component (A) concentration of 0.05% by mass. Table 1 shows the weight average molecular weight of the component (A) in the component (A) aqueous solution. A-1: "Acusol 587" (AA/AMPS copolymer, manufactured by DOW Chemical, monomer ratio AA:AMPS=79:21) A-2: "GS175" (AA/HAPS copolymer, manufactured by Nippon Shokubai Co., Ltd., monomer ratio AA: HAPS=82:18) A-3: "Aron A-6620" (AA/AMPS/t-BuAAM copolymer, manufactured by Toagosei Co., Ltd.)

(Component (B) aqueous solution) <Component (B1) aqueous solution> [3-Hydroxy-2,2'-imino disuccinate tetrasodium (HIDS) aqueous solution] Ultrapure water was added to 5 g of HIDS to make 100 mL, and mixed and stirred. Divide 1 mL of the obtained aqueous solution and dilute the volume to 100 mL with ultrapure water to prepare a HIDS aqueous solution with a concentration of 0.05% by mass. 〔Ethylenediaminetetraacetic acid (EDTA) aqueous solution〕 Ultrapure water was added to 5 g of EDTA to make 100 mL, and mixed and stirred. Divide 1 mL of the obtained aqueous solution and dilute the volume to 100 mL with ultrapure water to prepare an EDTA aqueous solution with a concentration of 0.05% by mass. <Component (B2) Aqueous Solution> [[(Phosphinomethyl)imino]bis(6,1-hexanediylnitrobismethylene)tetraphosphonic acid (BHMTPMP) aqueous solution] 5 g of BHMTPMP was added with ultrapure water to make 100 mL, and mixed and stirred. Divide 1 mL of the obtained aqueous solution and dilute the volume to 100 mL with ultrapure water to prepare a BHMTPMP aqueous solution with a concentration of 0.05% by mass. 〔1-Hydroxyethane-1,1-diphosphonic acid (HEDP) aqueous solution〕 Ultrapure water was added to 5 g of HEDP to make 100 mL, and the mixture was stirred. Divide 1 mL of the obtained aqueous solution and dilute the volume to 100 mL with ultrapure water to prepare an HEDP aqueous solution with a concentration of 0.05% by mass.

(Iron ion solution) Ultra-pure water was added to iron(III) chloride hexahydrate, and mixed and stirred to prepare an iron ion solution with an iron concentration of 250 mg/L. (Manganese ion solution) Ultra-pure water was added to manganese (II) chloride tetrahydrate and mixed and stirred to prepare a manganese ion solution with a manganese concentration of 250 mg/L.

[Example 1] 447.5 mL of ultrapure water was added to a 500 mL screw-mouth beaker, and then 5 mL of acid consumption solution, 25 mL of calcium ion solution, 10 mL of phosphate ion solution, 7.5 mL of AA/AMPS (A-1) aqueous solution as component (A), 1 mL of HIDS (B1-1) aqueous solution as component (B), 4 mL of iron ion solution, using 0.1 N sodium hydroxide aqueous solution and The pH of a 0.1 N sulfuric acid aqueous solution was adjusted to 8.5 to obtain test water added with component (A). Dilute 10 mL of the obtained test water and dilute it with ultra-pure water. Determine the test water before the test by the ascorbic acid reduction-molybdenum blue spectrophotometric method of Japanese Industrial Standards (JIS) K 0101:1998 The phosphate ion concentration (C ₀ ). In addition, the component (A) was not added to another 500 mL screw beaker, but ultrapure water was added instead of the component (A). Except for this, the same procedure was performed as described above to obtain a test without the component (A) added. water. Then, each screw-top bottle containing the test water added with the component (A) and the test water without the added component (A) was capped, and left standing in a thermostat at 60°C for 24 hours. After that, the screw-top bottle was taken out of the thermostat, and filtered using a filter with a pore size of 0.45 μm. After the filtered test water was cooled at room temperature, it was diluted with ultrapure water, and the phosphate ion concentration in the test water after the test was measured by the ascorbic acid reduction-molybdenum blue spectrophotometric method (with the addition of components ( A) test water: C _d , test water without added component (A): C _b ). Based on the obtained phosphate ion concentration (C _b ), the calcium phosphate precipitation inhibition rate (scale production inhibition rate) was calculated by the following formula (1). Calcium phosphate precipitation inhibition rate (%)=(C _d -C _b )/(C ₀ -C _b )×100 (1) C _d : Phosphate ion concentration after the test when component (A) is added C _b : No Phosphate ion concentration after test when component (A) is added C ₀ : Phosphate ion concentration before test when component (A) is added The reagents used as component (A) and component (B) are shown in Table 1 , The concentration of component (A), concentration of component (B), Fe concentration, Mn concentration, acid consumption, phosphate ion concentration and calcium ion hardness in the test water before standing in a constant temperature bath are shown in Table 2 . In addition, the calcium phosphate precipitation inhibition rate calculated based on the formula (1) is shown in Table 2. The higher the value of the calcium phosphate precipitation inhibition rate, the more inhibited the generation of scale. The precipitation inhibition rate of calcium phosphate is preferably about 70% or more.

[Example 2] In Example 1, 443.5 mL of ultrapure water was added, and 5.0 mL of the HIDS (B1-1) aqueous solution as the component (B) was added. Otherwise, the calcium phosphate precipitation inhibition rate was calculated in the same manner. The results and the concentration of component (A), component (B), Fe concentration, Mn concentration, acid consumption, phosphate ion concentration, and calcium ion hardness in the test water before standing in a constant temperature bath are shown in the table 2 in.

[Example 3] In Example 1, 438.5 mL of ultrapure water was added, and 10.0 mL of the HIDS (B1-1) aqueous solution as the component (B) was added. Otherwise, the calcium phosphate precipitation inhibition rate was calculated in the same manner. The results and the concentration of component (A), component (B), Fe concentration, Mn concentration, acid consumption, phosphate ion concentration, and calcium ion hardness in the test water before standing in a constant temperature bath are shown in the table 2 in.

[Comparative Example 1] In Example 1, 448.5 mL of ultrapure water was added, and except that the component (B) was not added, the calcium phosphate precipitation inhibition rate was calculated in the same manner. The results and the concentration of component (A), component (B), Fe concentration, Mn concentration, acid consumption, phosphate ion concentration, and calcium ion hardness in the test water before standing in a constant temperature bath are shown in the table 2 in.

[Example 4] In Example 2, except for adding 4 mL of a manganese ion solution instead of the iron ion solution, the calcium phosphate precipitation inhibition rate was calculated in the same manner. The results and the concentration of component (A), component (B), Fe concentration, Mn concentration, acid consumption, phosphate ion concentration, and calcium ion hardness in the test water before standing in a constant temperature bath are shown in the table 2 in.

[Example 5] In Example 4, 438.5 mL of ultrapure water was added, and 10.0 mL of the HIDS (B1-1) aqueous solution as the component (B) was added, and the calcium phosphate precipitation inhibition rate was calculated in the same manner. The results and the concentration of component (A), component (B), Fe concentration, Mn concentration, acid consumption, phosphate ion concentration, and calcium ion hardness in the test water before standing in a constant temperature bath are shown in the table 2 in.

[Comparative Example 2] In Example 4, 448.5 mL of ultrapure water was added, and except that the component (B) was not added, the calcium phosphate precipitation inhibition rate was calculated in the same manner. The results and the concentration of component (A), component (B), Fe concentration, Mn concentration, acid consumption, phosphate ion concentration, and calcium ion hardness in the test water before standing in a constant temperature bath are shown in the table 2 in.

[Example 6] In Example 1, 2 mL of the iron ion solution was added, and after the addition of the iron ion solution, 2 mL of the manganese ion solution was added, and other than that, the calcium phosphate precipitation inhibition rate was calculated in the same manner. The results and the concentration of component (A), component (B), Fe concentration, Mn concentration, acid consumption, phosphate ion concentration, and calcium ion hardness in the test water before standing in a constant temperature bath are shown in the table 2 in.

[Example 7] In Example 6, as the component (B), 1 mL of EDTA (B1-2) aqueous solution was added instead of the HIDS (B1-1) aqueous solution, and the calcium phosphate precipitation inhibition rate was calculated in the same manner. The results and the concentration of component (A), component (B), Fe concentration, Mn concentration, acid consumption, phosphate ion concentration, and calcium ion hardness in the test water before standing in a constant temperature bath are shown in the table 2 in.

[Comparative Example 3] In Example 6, 448.5 mL of ultrapure water was added, and except that the component (B) was not added, the calcium phosphate precipitation inhibition rate was calculated in the same manner. The results and the concentration of component (A), component (B), Fe concentration, Mn concentration, acid consumption, phosphate ion concentration, and calcium ion hardness in the test water before standing in a constant temperature bath are shown in the table 2 in.

[Example 8] In Example 1, 443.5 mL of ultrapure water was added, and after adding the iron ion solution, 4 mL of the manganese ion solution was added. Except for this, the calcium phosphate precipitation inhibition rate was calculated in the same manner. The results and the concentration of component (A), component (B), Fe concentration, Mn concentration, acid consumption, phosphate ion concentration, and calcium ion hardness in the test water before standing in a constant temperature bath are shown in the table 2 in.

[Example 9] In Example 8, 441.5 mL of ultrapure water was added, and 3.0 mL of the HIDS (B1-1) aqueous solution as the component (B) was added, and the calcium phosphate precipitation inhibition rate was calculated in the same manner. The results and the concentration of component (A), component (B), Fe concentration, Mn concentration, acid consumption, phosphate ion concentration, and calcium ion hardness in the test water before standing in a constant temperature bath are shown in the table 2 in.

[Example 10] In Example 8, 439.5 mL of ultrapure water was added, and 5.0 mL of the HIDS (B1-1) aqueous solution as the component (B) was added, and the calcium phosphate precipitation inhibition rate was calculated in the same manner. The results and the concentration of component (A), component (B), Fe concentration, Mn concentration, acid consumption, phosphate ion concentration, and calcium ion hardness in the test water before standing in a constant temperature bath are shown in the table 2 in.

[Example 11] In Example 8, as the component (B), a 1.0 mL EDTA (B1-2) aqueous solution was added instead of the HIDS (B1-1) aqueous solution, and the calcium phosphate precipitation inhibition rate was calculated in the same manner. The results and the concentration of component (A), component (B), Fe concentration, Mn concentration, acid consumption, phosphate ion concentration, and calcium ion hardness in the test water before standing in a constant temperature bath are shown in the table 2 in.

[Example 12] In Example 11, 441.5 mL of ultrapure water was added, and 3.0 mL of the EDTA (B1-2) aqueous solution as the component (B) was added, and the calcium phosphate precipitation inhibition rate was calculated in the same manner. The results and the concentration of component (A), component (B), Fe concentration, Mn concentration, acid consumption, phosphate ion concentration, and calcium ion hardness in the test water before standing in a constant temperature bath are shown in the table 2 in.

[Example 13] In Example 11, 439.5 mL of ultrapure water was added, and 5.0 mL of the EDTA (B1-2) aqueous solution as the component (B) was added, and the calcium phosphate precipitation inhibition rate was calculated in the same manner. The results and the concentration of component (A), component (B), Fe concentration, Mn concentration, acid consumption, phosphate ion concentration, and calcium ion hardness in the test water before standing in a constant temperature bath are shown in the table 2 in.

[Example 14, Example 15] In Example 8, as component (B), BHMTPMP (B2-1) aqueous solution was added in Example 14 instead of HIDS (B1-1) aqueous solution, and HEDP (B2-2) aqueous solution was used instead in Example 15 Except for the HIDS (B1-1) aqueous solution, the calcium phosphate precipitation inhibition rate was calculated in the same manner. The results and the concentration of component (A), component (B), Fe concentration, Mn concentration, acid consumption, phosphate ion concentration, and calcium ion hardness in the test water before standing in a constant temperature bath are shown in the table 2 in.

[Comparative Example 4] In Example 8, 444.5 mL of ultrapure water was added, and except that the component (B) was not used, the calcium phosphate precipitation inhibition rate was calculated in the same manner. The results and the concentration of component (A), component (B), Fe concentration, Mn concentration, acid consumption, phosphate ion concentration, and calcium ion hardness in the test water before standing in a constant temperature bath are shown in the table 2 in.

[Example 16] In Example 8, as the component (A), AA/AMPS/t-BuAAM copolymer (A-3) was used instead of AA/AMPS copolymer (A-1). Otherwise, the calcium phosphate precipitation was calculated in the same way Inhibition rate. The results and the concentration of component (A), component (B), Fe concentration, Mn concentration, acid consumption, phosphate ion concentration, and calcium ion hardness in the test water before standing in a constant temperature bath are shown in the table 2 in.

[Example 17] In Example 16, 439.5 mL of ultrapure water was added, and 5.0 mL of the HIDS (B1-1) aqueous solution as the component (B) was added, and the calcium phosphate precipitation inhibition rate was calculated in the same manner. The results and the concentration of component (A), component (B), Fe concentration, Mn concentration, acid consumption, phosphate ion concentration, and calcium ion hardness in the test water before standing in a constant temperature bath are shown in the table 2 in.

[Example 18] In Example 16, 434.5 mL of ultrapure water was added, and 10.0 mL of the HIDS (B1-1) aqueous solution as the component (B) was added, and other than that, the calcium phosphate precipitation inhibition rate was calculated in the same manner. The results and the concentration of component (A), component (B), Fe concentration, Mn concentration, acid consumption, phosphate ion concentration, and calcium ion hardness in the test water before standing in a constant temperature bath are shown in the table 2 in.

[Example 19] In Example 1, 435.5 mL of ultrapure water was added, as component (A), AA/HAPS copolymer (A-2) was used instead of AA/AMPS copolymer (A-1), and 10.0 mL of iron was added Except for the ion solution and 10.0 mL of manganese ion solution, the inhibition rate of calcium phosphate precipitation was calculated in the same manner. The results and the concentration of component (A), component (B), Fe concentration, Mn concentration, acid consumption, phosphate ion concentration, and calcium ion hardness in the test water before standing in a constant temperature bath are shown in the table 2 in.

[Example 20] In Example 19, 431.5 mL of ultrapure water was added, and 5.0 mL of the HIDS (B1-1) aqueous solution as the component (B) was added, and the calcium phosphate precipitation inhibition rate was calculated in the same manner. The results and the concentration of component (A), component (B), Fe concentration, Mn concentration, acid consumption, phosphate ion concentration, and calcium ion hardness in the test water before standing in a constant temperature bath are shown in the table 2 in.

[Example 21] In Example 19, 426.5 mL of ultrapure water was added, and 10.0 mL of the HIDS (B1-1) aqueous solution as the component (B) was added, and other than that, the calcium phosphate precipitation inhibition rate was calculated in the same manner. The results and the concentration of component (A), component (B), Fe concentration, Mn concentration, acid consumption, phosphate ion concentration, and calcium ion hardness in the test water before standing in a constant temperature bath are shown in the table 2 in.

[Reference example 1] In Example 1, 452.5 mL of ultrapure water was added, and except that the component (B) and the iron ion solution were not added, the calcium phosphate precipitation inhibition rate was calculated in the same manner. The results and the concentration of component (A), component (B), Fe concentration, Mn concentration, acid consumption, phosphate ion concentration, and calcium ion hardness in the test water before standing in a constant temperature bath are shown in the table 2 in.

[Table 1] Table 1 name Abbreviation Weight average molecular weight Ingredients (A) A-1 Acrylic acid/2-acrylamide-2-methylpropanesulfonic acid copolymer AA/AMPS copolymer 11000 A-2 Acrylic acid/2-hydroxy-3-allyloxypropanesulfonic acid copolymer AA/HAPS copolymer 11000 A-3 Acrylic acid/2-acrylamide-2-methylpropanesulfonic acid/tertiary butylacrylamide copolymer AA/AMPS/t-BuAAM copolymer 4500 Ingredients (B) Ingredients (B1) B1-1 Tetrasodium 3-hydroxy-2,2'-imino disuccinate HIDS - B1-2 Ethylenediaminetetraacetic acid EDTA - Ingredients (B2) B2-1 [(Phosphinomethyl)imino]bis(6,1-hexanediylnitrobismethylene)tetraphosphonic acid BHMTPMP - B2-2 1-hydroxyethane-1,1-diphosphonic acid HEDP -

[Table 2] Table 2 Ingredients (A) Ingredients (B) (A): (B) (mass ratio) Fe concentration (mg/L) Mn concentration (mg/L) Acid consumption (pH 8.3) (mgCaCO ₃ /L) PO ₄ ^3- concentration (mg/L) Ca hardness (mgCaCO ₃ /L) Inhibition rate(%) species Concentration (mg/L) species Concentration (mg/L) Example 1 A-1 7.5 B1-1 1 88:12 2 0 82 9 500 75 Example 2 A-1 7.5 B1-1 5 60:40 2 0 82 9 500 76 Example 3 A-1 7.5 B1-1 10 43:57 2 0 82 9 500 80 Comparative example 1 A-1 7.5 - 0 100:0 2 0 82 9 500 70 Example 4 A-1 7.5 B1-1 5 60:40 0 2 82 9 500 52 Example 5 A-1 7.5 B1-1 10 43:57 0 2 82 9 500 66 Comparative example 2 A-1 7.5 - 0 100:0 0 2 82 9 500 43 Example 6 A-1 7.5 B1-1 1 88:12 1 1 82 9 500 73 Example 7 A-1 7.5 B1-2 1 88:12 1 1 82 9 500 78 Comparative example 3 A-1 7.5 - 0 100:0 1 1 82 9 500 55 Example 8 A-1 7.5 B1-1 1 88:12 2 2 82 9 500 60 Example 9 A-1 7.5 B1-1 3 71:29 2 2 82 9 500 72 Example 10 A-1 7.5 B1-1 5 60:40 2 2 82 9 500 82 Example 11 A-1 7.5 B1-2 1 88:12 2 2 82 9 500 78 Example 12 A-1 7.5 B1-2 3 71:29 2 2 82 9 500 74 Example 13 A-1 7.5 B1-2 5 60:40 2 2 82 9 500 74 Example 14 A-1 7.5 B2-1 1 88:12 2 2 82 9 500 58 Example 15 A-1 7.5 B2-2 1 88:12 2 2 82 9 500 74 Comparative example 4 A-1 7.5 - 0 100:0 2 2 82 9 500 47 Example 16 A-3 7.5 B1-1 1 88:12 2 2 82 9 500 68 Example 17 A-3 7.5 B1-1 5 60:40 2 2 82 9 500 76 Example 18 A-3 7.5 B1-1 10 43:57 2 2 82 9 500 84 Example 19 A-2 7.5 B1-1 1 88:12 5 5 82 9 500 63 Example 20 A-2 7.5 B1-1 5 60:40 5 5 82 9 500 63 Example 21 A-2 7.5 B1-1 10 43:57 5 5 82 9 500 80 Reference example 1 A-1 7.5 - 0 100:0 0 0 82 9 500 91

From the results of Table 2, it can be seen that the case where the component (A) and the component (B) are included has an increased inhibition rate of calcium phosphate precipitation and the generation of scale is suppressed compared to the case where the component (B) is not included (comparative example).

Claims (13)

A scale inhibitor for cooling water, which is a scale inhibitor for cooling water containing one or more types of cooling water systems selected from iron, manganese, and aluminum, and comprising component (A) and component (B), The component (A) is selected from copolymers containing structural units derived from acrylic acid and structural units derived from 2-propenamide-2-methylpropanesulfonic acid and salts thereof, and structural units derived from acrylic acid One or more compounds in copolymers and their salts with structural units derived from 2-hydroxy-3-allyloxypropanesulfonic acid, The component (B) is selected from the group consisting of ethylenediaminetetraacetic acid and its salts, 3-hydroxy-2,2'-imino disuccinic acid tetrasodium and its salts, [(phosphinomethyl)imino ] One or more compounds of bis(6,1-hexanediylazobismethylene)tetraphosphonic acid and its salts, and 1-hydroxyethane-1,1-diphosphonic acid and its salts. The scale inhibitor for cooling water according to claim 1, wherein the copolymer containing a structural unit derived from acrylic acid and a structural unit derived from 2-propenamide-2-methylpropanesulfonic acid and its salt are Selected from copolymers of acrylic acid and 2-acrylamide-2-methylpropanesulfonic acid and their salts, and copolymers of acrylic acid, 2-acrylamide-2-methylpropanesulfonic acid and tertiary butylacrylamide One or more compounds in the group of substances and their salts. The scale inhibitor for cooling water according to claim 1 or 2, wherein a copolymer containing a structural unit derived from acrylic acid and a structural unit derived from 2-hydroxy-3-allyloxypropanesulfonic acid and its salt are The copolymer of acrylic acid and 2-hydroxy-3-allyloxypropanesulfonic acid and its salt. The scale inhibitor for cooling water according to any one of claims 1 to 3, wherein the cooling water system contains at least one selected from the group consisting of iron, manganese, and aluminum of 0.5 mg/L or more and 5.0 mg/L or less . The scale inhibitor for cooling water according to any one of claims 1 to 4, wherein the mass ratio of the component (A) to the component (B1) is 98:2-13:87, and the component (B1) It is one or more compounds selected from ethylenediaminetetraacetic acid and its salts, and 3-hydroxy-2,2'-iminodisuccinate tetrasodium and its salts. The scale inhibitor for cooling water according to any one of claims 1 to 4, wherein the mass ratio of the component (A) to the component (B2) is 98:2 to 38:62, and the component (B2) It is selected from [(phosphinomethyl)imino]bis(6,1-hexanediylnitrobismethylene)tetraphosphonic acid and its salts, and 1-hydroxyethane-1,1- One or more compounds of bisphosphonic acid and its salts. A scale inhibition method for cooling water, which is a scale inhibition method for cooling water containing one or more cooling water systems selected from iron, manganese, and aluminum, and uses a cooling water containing component (A) and component (B) Inhibitor, The component (A) is selected from copolymers containing structural units derived from acrylic acid and structural units derived from 2-propenamide-2-methylpropanesulfonic acid and salts thereof, structural units derived from acrylic acid and One or more compounds of copolymers derived from structural units of 2-hydroxy-3-allyloxypropanesulfonic acid and their salts, The component (B) is selected from the group consisting of ethylenediaminetetraacetic acid and its salts, 3-hydroxy-2,2'-imino disuccinic acid tetrasodium and its salts, [(phosphinomethyl)imino ] One or more compounds of bis(6,1-hexanediylazobismethylene)tetraphosphonic acid and its salts, and 1-hydroxyethane-1,1-diphosphonic acid and its salts. The scale inhibition method for cooling water according to claim 7, wherein the copolymer containing a structural unit derived from acrylic acid and a structural unit derived from 2-propenamide-2-methylpropanesulfonic acid and its salt are Selected from copolymers of acrylic acid and 2-acrylamide-2-methylpropanesulfonic acid and their salts, and copolymers of acrylic acid, 2-acrylamide-2-methylpropanesulfonic acid and tertiary butylacrylamide One or more compounds in the group of substances and their salts. The scale inhibition method for cooling water according to claim 7 or 8, wherein the copolymer containing a structural unit derived from acrylic acid and a structural unit derived from 2-hydroxy-3-allyloxypropanesulfonic acid and the same The salt is a copolymer of acrylic acid and 2-hydroxy-3-allyloxypropanesulfonic acid and its salt. The scale inhibition method for cooling water according to any one of claims 7 to 9, wherein the cooling water system contains more than one kind selected from iron, manganese, and aluminum of 0.5 mg/L or more and 5.0 mg/L or less . The scale inhibition method for cooling water according to any one of claims 7 to 10, wherein the concentration of the component (A) in the cooling water system is 3.0 mg/L or more and 20.0 mg/L or less Add the ingredient (A) in the same way. The scale inhibition method for cooling water according to any one of claims 7 to 11, wherein the concentration of the component (B1) in the cooling water system is 0.5 mg/L or more and 20.0 mg/L or less The component (B1) is added, and the component (B1) is one selected from the group consisting of ethylenediaminetetraacetic acid and its salts, and 3-hydroxy-2,2'-iminodisuccinate tetrasodium and its salts The above compound. The scale inhibition method for cooling water according to any one of claims 7 to 11, wherein the concentration of the component (B2) in the cooling water system is 0.5 mg/L or more and 5.0 mg/L or less The component (B2) is added, and the component (B2) is selected from [(phosphinomethyl)imino]bis(6,1-hexanediylaminobismethylene)tetraphosphonic acid and One or more compounds of its salt, 1-hydroxyethane-1,1-diphosphonic acid and its salt.