Aqueous metal anti-corrosion treatment method

Abstract

Provided is a water-based metal corrosion prevention treatment method that can be applied to a water quality range as wide as possible without using phosphorus compounds or metal salt compounds that impart a load to the water environment such as eutrophication or water-based toxicity as much as possible. Provided is an aqueous metal corrosion prevention treatment method using a copolymer of a (meth) acrylic acid monomer and a sulfonic acid-containing monomer, and a corrosion-resistant organic acid compound having an organic acid corrosion prevention effect index of 4 or more.

Description

Technical Field

[0001] The present invention relates to an aqueous metal corrosion protection treatment method and the like. Background Art

[0002] In water systems such as cooling water systems, metal components are often used in devices and flow paths. The parts of metal components installed in the water system that come into contact with water are susceptible to corrosion. For example, heat exchangers, reactors, pipes, etc. made of carbon steel, copper, galvanized steel, zinc, aluminum, aluminum alloy, stainless steel, or copper alloys are corroded due to contact with cooling water. In order to prevent this corrosion, metal components installed in the water system, especially the parts that come into contact with water, are usually subjected to corrosion protection treatment such as adding a chemical to the running water system.

[0003] For example, in order to suppress the corrosion of heat exchangers, reactors, and piping made of carbon steel, at least one anticorrosive phosphorus compound selected from orthophosphate, hexametaphosphate, hydroxyethylidene diphosphonate, phosphonobutane tricarboxylate, etc., has been added to water systems such as cooling water systems. However, the use of these phosphorus compounds is a cause of eutrophication in the water environment, so there are systems in various countries and regions that restrict the discharge of phosphorus outside the water system or the natural environment. Therefore, the treatment of phosphorus compounds and wastewater treatment requires a lot of attention and expenses.

[0004] For example, Patent Documents 1 and 2 propose methods for effectively suppressing corrosion of metals while minimizing the risk of causing such environmental problems.

[0005] Patent Document 1 proposes a method for inhibiting corrosion of metals, characterized in that in an open circulation cooling water system, by increasing the concentration of cooling water, the Langelier index is 1.5 or more and [SiO 2 ]×[CaH]≥2000[wherein, [SiO 2 ] is SiO in water 2 concentration (mg / L), [CaH] is the CaCO in water 3 The water quality is adjusted in a manner such that the calcium hardness (mg / L)] is reached, and then a copolymer of at least one selected from maleic acid, maleic anhydride and their water-soluble salts and isobutylene having a molecular weight of 1,000 to 20,000 is added.

[0006] Patent Document 2 proposes a method for inhibiting corrosion of metal in contact with an aqueous solution, which comprises adding (A) polyvalent metal ions and (B) a corrosion inhibitor or adhesion inhibitor (DCA) compound to the aqueous solution.

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: Japanese Patent Publication No. 04-033868

[0010] Patent Document 2: WO2010 / 062461 Summary of the invention

[0011] Problem that the invention aims to solve

[0012] The method proposed in Patent Document 1 is limited to water with high calcium hardness and high silica concentration, and has a problem in corrosion prevention that the water quality range in which it can be applied is narrow. In addition, the method proposed in Patent Document 2 shows a good corrosion prevention effect, but requires the addition of a small amount of metal salts such as aluminum, and requires further reduction of the load on the water environment.

[0013] Therefore, the main purpose of the present invention is to provide a water-based metal corrosion protection technology that can avoid using phosphorus compounds or metal salt compounds that cause loads to the water environment such as eutrophication or water toxicity as much as possible and can be applied to the widest possible range of water quality.

[0014] Solutions for solving problems

[0015] The present inventors have conducted intensive research and found that by using an organic acid corrosion protection effect index of 4 or more in combination with a polymer in an aqueous system, it is possible to provide a technology for metal corrosion protection treatment that can be applied to an aqueous system with a wide range of water quality as possible without using phosphorus compounds or metal salt compounds that cause loads to the aqueous environment such as eutrophication or water toxicity as much as possible. Thus, the present invention was completed as follows.

[0016] The present invention can provide an aqueous metal corrosion protection method using a copolymer of a (meth)acrylic acid monomer and a sulfonic acid-containing monomer and an organic acid corrosion protection compound having an organic acid corrosion protection effect index of 4 or more.

[0017] The present invention can also provide a water-based metal corrosion protection agent comprising a copolymer of a (meth)acrylic acid monomer and a sulfonic acid-containing monomer, and an organic acid corrosion protection compound having an organic acid corrosion protection effect index of 4 or more.

[0018] The present invention can also provide a water-based metal corrosion protection agent comprising: (A) a copolymer of a (meth) acrylic acid monomer and a sulfonic acid-containing monomer, (B) a dicarboxylic acid polymer, and (C) an organic acid corrosion protection compound having an organic acid corrosion protection effect index of 4 or more.

[0019] The present invention may also provide a water treatment agent comprising at least any one of (A) a copolymer of a (meth) acrylic acid monomer and a sulfonic acid-containing monomer, (B) a dicarboxylic acid polymer, or (C) an organic acid compound having an organic acid corrosion protection effect index of 4 or more, and when used for aqueous metal corrosion protection treatment, the water treatment agent is used in the form of (i) a combination of (A) and (C), or (ii) a combination of (A) to (C).

[0020] A water treatment agent for improving metal corrosion protection in water systems can also be provided, which contains an anticorrosive organic acid compound with an organic acid corrosion protection effect index of 4 or more, and improves metal corrosion protection in water systems by using (i) a copolymer of a (meth)acrylic acid monomer and a sulfonic acid-containing monomer, or by using (ii) a copolymer of a (meth)acrylic acid monomer and a sulfonic acid-containing monomer and a dicarboxylic acid-based polymer.

[0021] In addition, the present invention can also provide a method for improving water-based metal corrosion protection treatment, which uses an organic acid corrosion protection effect index of 4 or more, and utilizes (i) a copolymer of a (meth)acrylic acid monomer and a sulfonic acid-containing monomer, or (ii) a copolymer of a (meth)acrylic acid monomer and a sulfonic acid-containing monomer and a dicarboxylic acid polymer to improve water-based metal corrosion protection treatment.

[0022] Effects of the Invention

[0023] According to the present invention, it is possible to provide an aqueous metal corrosion protection technology which can minimize the use of phosphorus compounds or metal salt compounds that cause loads on the water environment such as eutrophication or water toxicity and can be applied to the widest possible range of water quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram showing an example of a water system used in the method of the present embodiment, for example, an example of a circulating cooling water system having a cooling tower, but the present invention is not limited thereto. DETAILED DESCRIPTION

[0025] Hereinafter, the preferred embodiment for implementing the present invention will be described. It should be noted that the embodiment described below shows an example of a representative embodiment of the present invention, and thus the scope of the present invention is not to be interpreted as narrow. In addition, in this specification, unless otherwise specified, the percentage is based on the expression of mass (mass / mass %). In addition, the upper limit value (below) and the lower limit value (above) of each numerical range (~) can be arbitrarily combined as needed.

[0026] 1. Water-based metal corrosion protection agent of this embodiment

[0027] The present embodiment can provide the technology of metal corrosion protection treatment of water system. The present embodiment can provide a kind of metal corrosion protection treatment method of water system, and it uses the multipolymer of (meth) acrylic acid monomer and sulfonic acid monomer and organic acid corrosion protection effect index to be more than 4 anticorrosive organic acid compound (hereinafter also referred to as "anticorrosive organic acid compound") . In the present embodiment, as a more preferred mode, from the viewpoint of the more synergistic excellent metal corrosion protection effect of exerting water system, it is preferred to use the above-mentioned (meth) acrylic acid monomer and the multipolymer of sulfonic acid monomer, dicarboxylic acid polymer and the above-mentioned anticorrosive organic acid compound to form these 3 kinds of components. In addition, the present embodiment preferably adds the above-mentioned 2 kinds of components or the above-mentioned 3 kinds of components to the water system with more than 5mg / L respectively.

[0028] As another aspect of the present embodiment, there can be provided an aqueous metal corrosion protection method using a copolymer of a (meth)acrylic acid monomer and a sulfonic acid-containing monomer, a dicarboxylic acid polymer, and an organic acid corrosion protection compound having an organic acid corrosion protection effect index of 4 or more.

[0029] In addition, the present embodiment can also provide a method for achieving a better corrosion protection effect in an aqueous system by using the aforementioned corrosion-resistant organic acid compound and a polymer having a structural unit derived from a (meth)acrylic acid monomer and a structural unit derived from a monomer having a sulfonic acid and / or a dicarboxylic acid polymer (more preferably a combination of these polymers).

[0030] According to this embodiment, the amount of phosphorus compounds or metal salt compounds used, which cause eutrophication or water toxicity, on the water environment can be greatly reduced, and the phosphorus compounds or metal salt compounds can be used as little as possible, and can be applied to a wide range of water quality. Furthermore, this embodiment uses a (meth) acrylic acid polymer and / or a dicarboxylic acid polymer having a sulfonic group as a polymer used in combination with the above-mentioned anti-corrosive organic acid compound, which can achieve scale suppression or scale prevention in the water system, and can be expected to help maintain the concentration of the anti-corrosive agent in the water system including the heat transfer surface.

[0031] The method in this embodiment can be a metal corrosion prevention method of a water system, and can also be a scale prevention method of a water system, or can be a metal corrosion prevention and scale prevention method of a water system. In addition, the metal corrosion prevention treatment method of the water system can be an operation method of the water system, thereby, it is possible to implement the stable operation of the water system that can significantly reduce the use of phosphorus compounds or metal salt compounds, or, it is also possible to implement the stable operation of the water system that does not cause environmental pollution problems caused by the use of phosphorus compounds or metal salt compounds as much as possible. In addition, the metal corrosion prevention treatment method of the water system also exerts excellent corrosion protection effects even if phosphorus compounds or metal salt compounds are not used, so it can be applied to a water system that is treated with non-phosphorus or non-metal salt compounds, and phosphorus treatment or metal salt compound treatment can not be carried out in the water system. In this way, environmental pollution problems are not caused as much as possible, and metal corrosion of the water system can be effectively suppressed, so it can contribute to the stable operation of the water system.

[0032] Hereinafter, this embodiment will be described in detail.

[0033] 1-1. Targets of metal corrosion protection in water systems

[0034] In the present embodiment, the material to be the object of corrosion protection is not particularly limited, and is a metal material. As the metal material, one or more of carbon steel, copper, galvanized steel, zinc, aluminum, aluminum alloy, stainless steel, and their alloys can be listed. Furthermore, among the metal materials, iron-based materials are preferred. As the iron-based materials, all iron materials (such as pure iron, carbon steel, cast iron, etc.) can be listed, and more preferably, carbon steel materials commonly used in carbon steel pipes (such as STB steel pipes) for boilers and heat exchangers are preferred. It should be noted that in JIS G 0203, the range of carbon steel is considered to be a range of carbon content of 0.02 mass% to about 2 mass%. More specifically, in carbon steel, carbon content of 0.25 mass% or less is considered to be low carbon steel, carbon content of 0.25-0.6 mass% is considered to be medium carbon steel, and carbon content of 0.6 mass% or more is considered to be high carbon steel. Low carbon steel to medium carbon steel are widely used, so carbon steel of 0.6 mass% or less is also considered to be ordinary steel. In addition, it is considered that the carbon content of cast iron is more than 2 mass %. In the present embodiment, among them, ordinary steel, low carbon steel and medium carbon steel, more preferably low carbon steel, can exhibit a better corrosion protection effect.

[0035] The object to which the corrosion protection treatment according to the present embodiment is preferably applied is preferably a metal material in contact with water or a metal member using a metal material in contact with water.

[0036] As the parts or devices using metal materials or metal components in the water system, various pipes such as water supply pipes, tubes, pumps, flow paths, heat exchangers, refrigerators, reactors, compressors, etc. can be listed, and one or more of them can be selected. More specifically, they or their metal parts or parts become the objects suitable for the anti-corrosion treatment of the present embodiment.

[0037] 1-2. Polymer

[0038] The polymer used in the present embodiment is not particularly limited, and is preferably an organic polymer compound that can be used in water systems. The polymer used in the present embodiment can be a polymer obtained from the same monomer, or a copolymer obtained using different monomers. The polymer used in the present embodiment can be obtained by a known manufacturing method such as an organic solvent polymerization method or an aqueous polymerization method, and a commercially available product can also be used. It should be noted that the form of the salt of the polymer is not particularly limited, and is preferably a salt that can make the monomer or polymer a water-soluble salt, and alkali metal salts based on sodium, potassium, etc., alkaline earth metal salts based on calcium, magnesium, etc., and ammonium salts based on ammonium, primary amines, tertiary amines, etc., can be listed, and one or more of them can be used.

[0039] The polymer used in the present embodiment is preferably a polymer whose corrosion protection effect is further improved compared with before the combination by using it in combination with the corrosion-resistant organic acid compound described later. As an index for determining the appropriate polymer used in the present embodiment, for example, the corrosion rate (mm / y) can be used, and the corrosion rate (mm / y) is preferably less than 0.11, more preferably less than 0.10, further preferably less than 0.08, and more preferably less than 0.06. Thus, in the combination with the corrosion-resistant organic acid compound, a better corrosion protection effect can be obtained.

[0040] The aforementioned polymer can list, for example, (meth) acrylic acid polymers (for example, (meth) acrylic acid polymers with sulfonic groups), dicarboxylic acid polymers (for example, maleic acid polymers), etc., and one or more of them can be used. As the polymer, preferably (meth) acrylic acid polymers (preferably (meth) acrylic acid polymers with sulfonic groups) and / or dicarboxylic acid polymers (preferably maleic acid polymers, epoxysuccinic acid polymers), more preferably a combination of (meth) acrylic acid polymers and dicarboxylic acid polymers, by using two kinds in combination, a better anticorrosion effect can be exerted. Thus, in the combined use with the anticorrosive organic acid compound, a better anticorrosion effect can be obtained. In addition, in the combined use with the (meth) acrylic acid polymers with sulfonic groups (more preferably acrylic acid polymers with sulfonic groups) and the anticorrosive organic acid compound and / or in the combined use with different polymers, the scale inhibition effect of the heat transfer surface can be exerted better, and the turbidity of the water in the water system can also be reduced better.

[0041] 1-2-1. (Meth)acrylic acid polymer

[0042] The polymer used in the present embodiment is preferably a (meth)acrylic acid polymer, more preferably a (meth)acrylic acid copolymer, more specifically, preferably a copolymer of a (meth)acrylic acid monomer and a sulfonic acid-containing monomer, and further preferably a copolymer of a (meth)acrylic acid monomer and a monomer containing an amide group and a sulfonic acid group and / or a copolymer of a (meth)acrylic acid monomer and a monomer containing a hydroxyl group and a sulfonic acid group. Thus, in combination with an anticorrosive organic acid compound, a better corrosion protection effect can be obtained. The monomer ratio (molar ratio (mol %)) of the (meth)acrylic acid monomer to the sulfonic acid-containing monomer in the aforementioned (meth)acrylic acid copolymer is preferably 99 to 1:1 to 99. The aforementioned (meth)acrylic acid copolymer is preferably a low molecular weight. It should be noted that the (meth)acrylic acid polymer can be a water-soluble salt, and the salt can appropriately adopt the salt described in the above polymer.

[0043] <(Meth)acrylic acid monomer>

[0044] The aforementioned (meth)acrylic acid monomer is not particularly limited, and examples thereof include (meth)acrylic acid and its salts, and one or more selected from these groups can be used. In the present embodiment, "(meth)acrylic acid" refers to at least one selected from the group consisting of "acrylic acid" and "methacrylic acid". Among them, acrylic acid or its salt is preferred. It should be noted that among the (meth)acrylic acid monomers used in the present embodiment, when containing a sulfonic group, it is preferably used as the <sulfonic acid monomer> described later, in which case the aforementioned (meth)acrylic acid monomer is preferably a (meth)acrylic acid monomer other than the "(meth)acrylic acid monomer containing a sulfonic group".

[0045] <Sulfonic Acid Monomer>

[0046] The sulfonic acid monomer is not particularly limited, but is preferably a monomer containing a sulfonic group from the viewpoint of exerting a better anticorrosion effect, and the monomer is more preferably an unsaturated monomer. Examples of the sulfonic acid monomer include, but are not limited to, monoethylenically unsaturated sulfonic acid monomers, and the like. In addition, the monoethylenically unsaturated sulfonic acid monomer may also be in the form of a salt (e.g., a Na salt).

[0047] As the sulfonic acid monomer, for example, monomers having an amide group and a sulfonic group (preferably a monomer having an amide group and a sulfonic group with 6 to 9 carbon atoms), monomers having a hydroxyl group and a sulfonic group (preferably a monomer having a hydroxyl group and a sulfonic group with 6 to 9 carbon atoms), sulfonates of aliphatic conjugated dienes (preferably a sulfonate of aliphatic conjugated dienes with 4 to 15 carbon atoms), and salts thereof can be cited, and one or more selected from these groups can be used. Among them, monomers having an amide group and a sulfonic group (preferably a monomer having an amide group and a sulfonic group with 6 to 9 carbon atoms) and / or monomers having a hydroxyl group and a sulfonic group (preferably a monomer having a hydroxyl group and a sulfonic group with 6 to 9 carbon atoms) are preferred. In addition, the "sulfonic group" of the monomer may be a sulfonic group that may have a substituent, and for example, an alkyl sulfonic group can be cited, and the carbon number of the "alkyl" of the alkyl sulfonic group is preferably 1 to 8, and more preferably a methyl propyl sulfonic group (also called a tert-butyl sulfonic group). Thus, in the combined use with the anticorrosive organic acid compound, a better corrosion protection effect and a better anti-scaling effect can be obtained.

[0048] Examples of the monomer having an amide group and a sulfonic group include (meth)acrylamide alkylpropanesulfonic acid and crotonamide alkylpropanesulfonic acid. More specifically, examples include 2-acrylamide-2-methylpropanesulfonic acid (AMPS), 3-acrylamide-3,3-dimethylpropanesulfonic acid and salts thereof. One or more selected from these groups can be used.

[0049] Examples of the monomer having a hydroxyl group and a sulfonic group include 3-allyloxy-2-hydroxy-1-propanesulfonic acid (HAPS), 3-methacryloyloxy-2-hydroxypropanesulfonic acid, 3-allyloxy-1-hydroxypropane-2-sulfonic acid, 3-methacryloyloxy-1-hydroxypropane-2-sulfonic acid, and salts thereof. One or more selected from these groups can be used.

[0050] Examples of the sulfonated product of the aliphatic conjugated diene include sulfonated products of 1,3-butadiene and sulfonated products of 2,3-dimethyl-1,3-butadiene. One or more kinds selected from these groups can be used.

[0051] As more preferred sulfonic acid monomers, unsaturated monomers containing sulfonic groups such as (meth)acrylamide methylpropanesulfonic acid, 3-allyloxy-2-hydroxypropanesulfonic acid, (meth)allylsulfonic acid, vinylsulfonic acid, styrenesulfonic acid, and 2-sulfoethyl methacrylate, and their salts, etc., can be listed, and one or more selected from these groups can be used. Among them, at least one monomer selected from 2-acrylamide-2-methylpropanesulfonic acid (AMPS) and 3-allyloxy-2-hydroxypropanesulfonic acid (HAPS) is preferred, and AMPS and / or HAPS are more preferred. Thus, in the combined use with the anticorrosive organic acid compound, a better anticorrosion effect and a better anti-scaling effect can be obtained.

[0052] Examples of the other monomers include N-vinyl monomers such as N-vinylpyrrolidone, N-vinylformamide, N-vinylacetamide, N-vinyl-N-methylformamide, N-vinyl-methylacetamide, and N-vinyloxazolidinone; nitrogen-containing nonionic unsaturated monomers such as (meth)acrylamide, tert-butylacrylamide, N,N-dimethylacrylamide, and N-isopropylacrylamide; hydroxyl-containing unsaturated monomers such as 3-(meth)allyloxy-1,2-dihydroxypropane, (meth)allyl alcohol, and isoprenol; polyoxyethylene-containing unsaturated monomers such as compounds obtained by adding about 1 to 200 mol of ethylene oxide to (meth)allyl alcohol; (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, and hydroxyethyl (meth)acrylate; unsaturated carboxylic acid monomers such as dicarboxylic acid and itaconic acid; and aromatic unsaturated monomers such as styrene. One or more monomers selected from these groups may be used.

[0053] <Preferred (meth)acrylic polymer>

[0054] The aforementioned (meth)acrylic acid polymer is more preferably a (meth)acrylic acid polymer containing a sulfonic group in the molecule, further preferably a (meth)acrylic acid polymer containing a sulfonic acid group in the molecule, and more preferably a copolymer of a (meth)acrylic acid monomer and a sulfonic acid monomer. The sulfonic acid monomer is preferably an unsaturated monomer containing a sulfonic acid group. As a more preferred specific example, there can be listed a homopolymer or copolymer (copolymer) formed by polymerizing or copolymerizing one or more monomers selected from the group consisting of (meth)acrylic acid (preferably acrylic acid (AA)); 2-hydroxy-3-(allyloxy)-1-propanesulfonic acid (HAPS), 2-acrylamide-2-methylpropanesulfonic acid (AMPS), etc.

[0055] <Production Example of (Meth)Acrylic Acid Copolymer>

[0056] The aforementioned (meth)acrylic acid copolymer can be produced by a known production method. A preferred copolymer is a polymer obtained by copolymerizing (i) a (meth)acrylic acid monomer and (ii) a sulfonic acid monomer selected from a monomer having an amide group and a sulfonic group, a monomer having a hydroxyl group and a sulfonic group, etc. at a predetermined mass ratio. It should be noted that any monomer can be used within the range that does not impair the effects of the present invention.

[0057] A more preferred (meth)acrylic copolymer is a polymer obtained by copolymerizing (i) an acrylic acid monomer and (ii) at least one sulfonic acid monomer selected from 2-acrylamide-2-methylpropanesulfonic acid and 3-allyloxy-2-hydroxypropanesulfonic acid at a predetermined mass ratio.

[0058] A more preferred (meth)acrylic acid copolymer is one or more selected from the group consisting of a copolymer of an acrylic acid (AA) monomer and a 2-acrylamide-2-methylpropanesulfonic acid (AMPS) monomer, a copolymer of an acrylic acid (AA) monomer and a 3-allyloxy-2-hydroxypropanesulfonic acid (HAPS) monomer, etc. The preferred predetermined molar ratio of the (meth)acrylic acid monomer to the sulfonic acid monomer is, for example, 1 to 99:99 to 1, and the molar ratio can be appropriately adopted as described later in the <above molar ratio (mol %) in the above (meth)acrylic acid copolymer>.

[0059] <Molar Ratio of the (Meth)Acrylic Acid Monomer to the Sulfonic Acid Monomer (mol %)>

[0060] The molar ratio (mol %: total amount 100) of the (meth)acrylic acid monomer to the sulfonic acid monomer in the copolymer of the (meth)acrylic acid monomer and the sulfonic acid monomer is not particularly limited. The preferred lower limit of the (meth)acrylic acid monomer is preferably 50 or more, more preferably 60 or more, more preferably 70 or more, more preferably 75 or more, and more preferably 80 or more. The preferred upper limit of the (meth)acrylic acid monomer is preferably 99 or less, more preferably 98 or less, further preferably 97 or less, more preferably 95 or less, and further preferably 90 or less. As a more preferred numerical range of the molar ratio of the acrylic acid monomer to the sulfonic acid monomer, the acrylic acid monomer:sulfonic acid monomer is more preferably 75:25 to 93:7, and more preferably 80:20 to 90:10. By making the copolymer of the (meth)acrylic acid monomer and the sulfonic acid monomer have this molar ratio, a better corrosion protection effect and a better anti-scaling effect can be exerted. The molar ratio can be appropriately adopted as the molar ratio (%) of the (meth)acrylic acid monomer and the sulfonic acid monomer to constitute a copolymer such as an AA / AMPS polymer or an AA / HAPS polymer described later.

[0061] As a more preferred embodiment of the molar ratio in the aforementioned (meth)acrylic acid-based copolymer, the molar ratio (mol %) of the (meth)acrylic acid monomer to the sulfonic acid monomer containing an amide group and / or a hydroxyl group in the copolymer of the (meth)acrylic acid monomer and the sulfonic acid monomer containing an amide group and / or a hydroxyl group is more preferably 75:25 to 93:7, and further preferably 80:20 to 90:10. By setting this molar ratio, a better corrosion protection effect can be exerted. It should be noted that the molar ratio can appropriately adopt the preferred lower limit and preferred upper limit of the <molar ratio in the copolymer of the aforementioned (meth)acrylic acid monomer and the sulfonic acid monomer> described above.

[0062] In addition, as a more preferred embodiment of the molar ratio in the aforementioned (meth)acrylic copolymer, in the case of AA / AMPS polymers and AA / HAPS polymers, the AA / AMPS ratio and the AA / HAPS ratio (mol%) (AA:AMPS or HAPS) are more preferably 75:25 to 93:7, and further preferably 80:20 to 90:10. By setting this molar ratio, a better corrosion protection effect can be exerted. It should be noted that the molar ratio can appropriately adopt the preferred lower limit and preferred upper limit of the <molar ratio in the copolymer of the aforementioned (meth)acrylic monomer and the sulfonic acid monomer> described above.

[0063] <Weight Average Molecular Weight of (Meth)Acrylic Copolymer>

[0064] The weight average molecular weight of the copolymer of the (meth)acrylic acid monomer and the sulfonic acid monomer obtained by the GPC method is not particularly limited, and its preferred lower limit is preferably 500 or more, more preferably 1000 or more, further preferably 2000 or more, further preferably 3000 or more, further preferably 4000 or more, and its preferred upper limit is preferably 100000 or less, more preferably 50000 or less, further preferably 40000 or less, more preferably 30000 or less, and more preferably 20000 or less. The preferred numerical range of the (meth)acrylic acid monomer and the sulfonic acid monomer is more preferably 3000 to 30000, and preferably 4000 to 20000. The preferred lower limit and upper limit of the preferred weight average molecular weight of the AA / AMPS polymer and the AA / HAPS polymer can be appropriately adopted, and the preferred numerical range is preferably 3000 to 30000, and more preferably 4000 to 20000. By adjusting the weight average molecular weight to this level, a better corrosion prevention effect and scale prevention effect can be exhibited.

[0065] The weight average molecular weight of the polymer in this specification can be obtained by gel permeation chromatography (GPC analysis) using a standard substance. When sodium polyacrylate is used as a standard substance, it can be expressed as a value converted to sodium polyacrylate.

[0066] 1-2-2. Dicarboxylic acid polymers

[0067] The polymer used in this embodiment is preferably a dicarboxylic acid polymer, more preferably a maleic acid polymer, more specifically, preferably a polymer of a maleic acid monomer, a copolymer of a maleic acid monomer and other monomers (such as an aromatic unsaturated monomer, an unsaturated hydrocarbon monomer, etc.), and further preferably a polymer of a maleic acid monomer, a copolymer of a maleic acid monomer and an unsaturated hydrocarbon monomer (preferably an isobutylene monomer). Thus, in the combined use with an anticorrosive organic acid compound, a better anticorrosion effect and antiscaling effect can be obtained.

[0068] <Dicarboxylic acid polymer and its production example>

[0069] The aforementioned dicarboxylic acid polymer (homopolymer or copolymer) can be manufactured by a known manufacturing method. A preferred copolymer is a polymer obtained by polymerizing (i) a maleic acid monomer and (ii) a monomer having an unsaturated bond selected from aromatic unsaturated monomers such as styrene, unsaturated hydrocarbon monomers such as isobutylene, etc., in a prescribed mass usage ratio. It should be noted that any monomer can be used within the scope of not impairing the effect of the present invention.

[0070] Examples of dicarboxylic acid polymers include polymers (homopolymers, copolymers) obtained by polymerizing one or more dicarboxylic acid monomers selected from maleic acid (anhydride), epoxysuccinic acid, itaconic acid, etc. in an aqueous solution containing these monomers; monomers having unsaturated bonds other than dicarboxylic acid monomers may also be contained in the aqueous solution, and polymers (copolymers) obtained by polymerizing carboxylic acid monomers and other monomers having unsaturated bonds may be used, and one or more selected from these monomers may be used.

[0071] As the aforementioned dicarboxylic acid monomer, there is no particular limitation, and examples thereof include organic acid monomers such as maleic acid monomers, epoxysuccinic acid monomers, itaconic acid monomers, and their ester monomers. In addition, unsaturated organic acid monomers and their esters are preferred. One or more selected from these can be used.

[0072] The monomer having an unsaturated bond other than the above-mentioned dicarboxylic acid monomer is not particularly limited, and examples thereof include N-vinyl monomers such as N-vinylpyrrolidone, N-vinylformamide, N-vinylacetamide, N-vinyl-N-methylformamide, N-vinyl-methylacetamide, and N-vinyloxazolidinone; nitrogen-containing nonionic unsaturated monomers such as (meth)acrylamide, tert-butylacrylamide, N,N-dimethylacrylamide, and N-isopropylacrylamide; 3-(meth)allyloxy-1,2-dihydroxypropane, Hydroxyl-containing unsaturated monomers such as (meth)allyl alcohol and isoprene alcohol; polyoxyethylene-containing unsaturated monomers such as compounds obtained by adding about 1 to 200 mol of ethylene oxide to (meth)allyl alcohol; (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, and hydroxyethyl (meth)acrylate; unsaturated carboxylic acid monomers such as (meth)acrylic acid and itaconic acid; aromatic unsaturated monomers such as styrene; unsaturated hydrocarbons such as isobutylene, etc., and one or more selected from them can be used.

[0073] As the aforementioned dicarboxylic acid polymer, it is more preferred to be one or more selected from maleic acid polymers, epoxysuccinic acid polymers (preferably epoxysuccinic acid homopolymers), and itaconic acid polymers, further preferred to be maleic acid polymers and / or epoxysuccinic acid polymers, and further preferred to be maleic acid polymers.

[0074] The weight average molecular weight of the dicarboxylic acid polymer is not particularly limited, and more specifically, it is more preferably 250 or 500 to 10,000, more preferably 500 to 5,000, more preferably 500 to 3,000, and more preferably 500 to 2,000. The weight average molecular weight of the polymer in this specification can be obtained by gel permeation chromatography (GPC analysis) using a standard substance. It should be noted that when sodium polyacrylate is used as a standard substance, it can be expressed as a value converted from sodium polyacrylate.

[0075] 1-2-2-1. Maleic acid polymers

[0076] Among the aforementioned dicarboxylic acid polymers, maleic acid polymers are preferred. The maleic acid polymer is preferably a polymer comprising a maleic acid monomer as a structural unit, and the maleic acid polymer can be any one of a homopolymer or a copolymer. As a homopolymer, polymaleic acid, for example, comprising a maleic acid monomer, which is polymerized using a maleic acid monomer, can be listed. In addition, as a copolymer, there is no particular limitation, and copolymers of maleic acid monomers and other monomers (unsaturated monomers) copolymerizable therewith can be listed. It should be noted that the maleic acid polymer can be a water-soluble salt, and the salt can appropriately adopt the salt described in the above-mentioned polymer.

[0077] <Maleic Acid Monomer>

[0078] The maleic acid monomer is not particularly limited, and examples thereof include maleic acid monomers (eg, maleic anhydride, maleic acid, maleate, etc.), maleate ester monomers, and one or more selected from these monomers can be used.

[0079] Among the maleic acid monomers, maleic acid monomers are preferred. Maleic anhydride monomers include maleic anhydride and hydrolyzates of maleic anhydride (maleic acid).

[0080] Examples of maleic acid esters include esters with alcohols of saturated hydrocarbons such as methanol and ethanol, alcohols of unsaturated hydrocarbons such as allyl alcohol and methallyl alcohol, polyalkylene alcohols, polyoxyalkylene monomethyl ethers, polyoxyalkylene monoallyl ethers and other polyalkylene glycol derivatives, and one or more selected from these can be used.

[0081] <Copolymerizable Monomers Other Than Maleic Acid Monomers>

[0082] There are no particular limitations on the copolymerizable monomers other than the maleic acid monomers, and examples of the compounds described in the above-mentioned "monomers having unsaturated bonds other than dicarboxylic acid monomers" can be appropriately used. Among the aforementioned monomers copolymerizable with the maleic acid monomers, unsaturated hydrocarbon monomers (preferably ethylenically unsaturated hydrocarbon monomers) are preferred, and the unsaturated hydrocarbon monomers may be either chain or cyclic, and are preferably monoethylenically unsaturated hydrocarbon monomers, and are preferably unsaturated hydrocarbon monomers having 4 to 6 carbon atoms. Among the copolymerizable monomers, chain monoethylenically unsaturated hydrocarbon monomers are preferred, and among chain monoethylenically unsaturated hydrocarbon monomers, butene monomers are more preferred, and isobutylene monomers are further preferred. Thus, in the combined use with the anticorrosive organic acid compound, a better anticorrosion effect can be obtained.

[0083] Examples of the monoethylenically unsaturated hydrocarbons having 4 to 6 carbon atoms in the monomers copolymerizable with the maleic acid monomers include chain monoethylenically unsaturated hydrocarbons such as butene (isobutylene (isobutene), α-butene (1-butene), cis-β-butene (cis-2-butene), trans-β-butene (trans-2-butene)), 1-pentene, 2-pentene, methylbutene, methylpentene, and hexene; and cyclic monoethylenically unsaturated hydrocarbons such as cyclopentene, methylcyclopentene, and cyclohexene. One or more of these can be used. Thus, in the combined use with the anticorrosive organic acid compound, a better anticorrosive effect can be obtained.

[0084] <Preferred maleic acid polymer>

[0085] The preferred maleic acid polymer is preferably a copolymer of a maleic acid monomer and a monoethylenically unsaturated hydrocarbon monomer (preferably an isobutylene monomer), and / or polymaleic acid (preferably a homopolymer of a maleic acid monomer). Thus, in combination with an anticorrosive organic acid compound, a better anticorrosive effect can be obtained.

[0086] <Molar Ratio of the Maleic Acid Monomer to the Other Monomers (mol %)>

[0087] The molar ratio (mol %: total amount 100) of the maleic acid monomer to other monomers in the maleic acid polymer is not particularly limited, but the preferred lower limit of the maleic acid monomer is preferably 50% or more, more preferably 60% or more, and even more preferably 70% or more.

[0088] As a more preferred embodiment of the molar ratio in the aforementioned maleic acid-based copolymer, the molar ratio (mol %: total amount 100) of the maleic acid monomer to the monoethylenically unsaturated hydrocarbon (preferably C 4-6) monomer is not particularly limited, and the preferred lower limit of the maleic acid monomer is preferably 50 or more, more preferably 60 or more, and more preferably 70 or more.

[0089] <Weight Average Molecular Weight of Maleic Acid-Based Polymer>

[0090] The weight average molecular weight of the maleic acid polymer obtained by GPC is not particularly limited, but its preferred lower limit is preferably 250 or more, more preferably 500 or more, and its preferred upper limit is preferably 10000 or less, more preferably 8000 or less, further preferably 5000 or less, more preferably 3000 or less, and its preferred numerical range is preferably 500 to 5000, more preferably 500 to 3000. Thus, in the combined use with the anticorrosive organic acid compound, a better anticorrosion effect and a better antiscaling effect can be obtained.

[0091] 1-3. Anticorrosive organic acid compounds

[0092] The corrosion-resistant organic acid compound used in the present embodiment is not particularly limited, but is preferably an organic acid compound having a corrosion-resistant effect on metal materials in contact with water.

[0093] As an index indicating the corrosion protection effect of the organic acid of the corrosion-resistant organic acid compound used in the present embodiment (hereinafter also referred to as "organic acid corrosion protection effect index"), as a more preferred lower limit, from the viewpoint of exerting a better corrosion protection effect, it is preferably 4 or more, more preferably 4.5 or more, and further preferably 5 or more. In addition, as a more preferred upper limit, it is not particularly limited, but it is preferably 20 or less, more preferably 18 or less, further preferably 15 or less, and more preferably 14 or less. As the preferred numerical range, it is more preferably 4 to 15. Thus, in the combined use with the polymer, a better corrosion protection effect can be obtained. The organic acid corrosion protection effect index can be obtained by the formula of <Organic Acid Corrosion Protection Effect Index> shown in [Examples] described later.

[0094] For the anticorrosive organic acid compound, it is preferred to determine whether the organic acid anticorrosive effect index can exhibit an anticorrosive effect, for example, by considering that the corrosion rate of test water containing an organic acid and a polymer is slower or within a set numerical range.

[0095] More preferably, the organic acid corrosion protection effect index that can exert the corrosion protection effect can be determined by using the <method> described in Test Example 1 in the [Examples] described later and the calculation formula of the corrosion rate (mm / y). The corrosion rate (mm / y) that can be determined to exert the corrosion protection effect is preferably less than 0.10, more preferably 0.08 or less, further preferably 0.05 or less, and more preferably 0.03 or less. For example, the organic acid corrosion protection effect index of the corrosion-resistant organic acid compound in the range of a corrosion rate of 0.03 or less can be set as an index that can obtain the corrosion protection effect.

[0096] The corrosion-resistant organic acid compound preferably has a hydroxyl group and / or a carboxylic acid group as a functional group, and more preferably has a hydroxyl group and a carboxylic acid group as a functional group.

[0097] The number of hydroxyl groups possessed by the aforementioned anticorrosive organic acid compound is not particularly limited, and may be any one of one or more, and as its preferred lower limit, it is preferably 0 or 1 or more, thereby, in combination with a polymer, a better anticorrosion effect can be obtained. In addition, the number of carboxylic acid groups possessed by the aforementioned anticorrosive organic acid compound is not particularly limited, and may be any one of one or more, and as its preferred lower limit, it is preferably 1 or more, more preferably 2 or more, thereby, in combination with a polymer, a better anticorrosion effect can be obtained. It is important that at least one carboxylic acid group is more than one, but it is believed that when the number of hydroxyl groups and carboxylic acid groups is large, it is good in exerting the effect of the present embodiment. The aforementioned anticorrosive organic compound has at least one or more carboxylic acid, and the sum of the number of carboxylic acid groups and hydroxyl groups is preferably 4 or more, more preferably 5 or more, and further preferably 6 or more. The upper limit of the number of carboxylic acid groups and / or hydroxyl groups in the molecule possessed by the aforementioned anticorrosive organic acid compound is not particularly limited, and is limited according to the molecular weight.

[0098] The molecular weight (MW) of the corrosion-resistant organic acid compound is not particularly limited, and its preferred lower limit is preferably 100 or more, more preferably 125 or more, and further preferably 150 or more. In addition, its preferred upper limit is not particularly limited, but is preferably 300 or less, and more preferably 290 or less. Thus, in the combined use with the polymer, a better corrosion protection effect can be obtained.

[0099] As the aforementioned corrosion-resistant organic acid compound, for example, citric acid, tartaric acid, mucic acid, glucoheptonic acid, butanetetracarboxylic acid, iminodiamalic acid, 3-hydroxy-2,2'-iminodisuccinic acid, etc. can be listed, but are not limited to these. One or more selected from them can be used. Thus, in the combined use with a polymer, a better corrosion protection effect can be obtained. Among them, from the viewpoint of a better corrosion protection effect and a better anti-scaling effect achieved by using in combination with a polymer, iminodiamalic acid is more preferred.

[0100] 1-4. Combination of the aforementioned polymer and the aforementioned anticorrosive organic acid compound, preferred amount and preferred ratio of each component

[0101] In the present embodiment, in the water-based anticorrosion treatment method for suppressing the corrosion of metals in contact with the water system, by using the aforementioned polymer and the aforementioned anticorrosive organic acid compound, these components are present in the water system, and a better metal corrosion protection effect can be exerted. Hereinafter, the more preferred usage amount of each component for the water system, or the content ratio in the agent, the blending ratio, etc. are described.

[0102] In addition, in other schemes of the present embodiment, it is also possible to provide a technology for strengthening, enhancing or improving the metal corrosion protection effect brought about by the aforementioned polymer present in the water system by combining the aforementioned polymer and the aforementioned anti-corrosion organic acid compound in the water system. The following describes a better mass usage ratio or mass content ratio in the agent.

[0103] <Preferred usage or addition amount of the aforementioned polymer and the aforementioned anticorrosive organic acid compound>

[0104] There is no particular limitation on the amount of the aqueous polymer used or added (mg solid / L, hereinafter referred to as "mg / L"), but the preferred lower limit is preferably 1 mg / L or more, more preferably 2 mg / L or more, more preferably 3 mg or 4 mg / L or more, more preferably 5 mg / L or more, more preferably 6 mg / L or more, more preferably 7 mg / L or more, and more preferably 8 mg / L or more. In addition, there is no particular limitation on the preferred upper limit, but from the viewpoint of environmental load and cost reduction, it is preferably 100 mg / L or less, more preferably 50 mg / L or less, more preferably 40 mg / L or less, more preferably 30 mg / L or less, and further preferably 20 mg / L or less.

[0105] The amount of the aqueous (meth)acrylic acid polymer used or added (mg solid / L, hereinafter referred to as "mg / L") is not particularly limited, but is preferably 1 mg / L or more, more preferably 2 mg / L or more, more preferably 3 mg or 4 mg / L or more, more preferably 5 mg / L or more, more preferably 6 mg / L or more, more preferably 7 mg / L or more, and more preferably 8 mg / L or more. The upper limit is not particularly limited, but is preferably 100 mg / L or less, more preferably 50 mg / L or less, more preferably 40 mg / L or less, more preferably 30 mg / L or less, and more preferably 20 mg / L or less, from the viewpoint of environmental load and cost reduction.

[0106] As a further more preferred embodiment, the amount of the aqueous sulfonic acid group-containing (meth)acrylic acid polymer used or added (mg solid / L) may be appropriately adopted from the preferred lower limit and upper limit of the amount of the (meth)acrylic acid polymer used, etc., and as a more preferred numerical range, it is more preferably 3 to 50 mg / L, and more preferably 5 to 20 mg / L. Furthermore, as a further more preferred embodiment, the amount of the aqueous AA / AMPS polymer and / or the AA / HAPS polymer used (mg solid / L) may be appropriately adopted from the preferred lower limit and upper limit of the amount of the (meth)acrylic acid polymer used, and as a more preferred numerical range, it is more preferably 3 to 50 mg / L, and more preferably 5 to 20 mg / L.

[0107] The amount of the aqueous dicarboxylic acid polymer used or added (mg solid / L, hereinafter referred to as "mg / L") is not particularly limited, but is preferably 1 mg / L or more, more preferably 2 mg / L or more, more preferably 3 mg or 4 mg / L or more, more preferably 5 mg / L or more, more preferably 6 mg / L or more, more preferably 7 mg / L or more, and more preferably 8 mg / L or more. The preferred upper limit is not particularly limited, but is preferably 100 mg / L or less, more preferably 50 mg / L or less, more preferably 40 mg / L or less, more preferably 30 mg / L or less, and more preferably 20 mg / L or less, from the viewpoint of environmental load and cost reduction.

[0108] As a further more preferred embodiment, the preferred lower limit and upper limit of the aforementioned maleic acid polymer usage amount, etc. can be appropriately adopted for the usage or addition amount (mg solid / L) of the aqueous maleic acid polymer, and as a more preferred numerical range, 3 to 50 mg / L is more preferred, and 5 to 20 mg / L is more preferred. Furthermore, as a more preferred embodiment, the preferred lower limit and upper limit of the aforementioned maleic acid polymer usage amount can be appropriately adopted for the usage (mg solid / L) of the aqueous MA homopolymer and / or MA / IB polymer, and as a more preferred numerical range, 3 to 50 mg / L is more preferred, and 5 to 20 mg / L is more preferred.

[0109] In the present embodiment, when different systems of polymers are used for the water system, for example, when a (meth) acrylic acid polymer and a dicarboxylic acid polymer having a sulfonic group are used in combination, the above-mentioned usage of the aforementioned polymers can be set to the respective usage. When a plurality of such different systems of polymers are used, the total usage or total addition of the aforementioned polymers is not particularly limited, and as a preferred lower limit, it is preferably 6 mg / L or more, more preferably 8 mg / L or more, further preferably 10 mg / L or more, more preferably 12 mg / L or more, more preferably 14 mg / L or more, and more preferably 16 mg / L or more. In addition, as a preferred upper limit, it is not particularly limited, but from the viewpoint of environmental load and cost reduction, it is preferably 200 mg / L or less, more preferably 100 mg / L or less, and further preferably 80 mg / L, 60 mg / L or 40 mg / L or less.

[0110] In the present embodiment, when a (meth)acrylic acid polymer and a dicarboxylic acid polymer having a sulfonic group are used in combination in an aqueous system, their usage ratio in the aqueous system or their blending ratio in the agent is not particularly limited, and can be obtained by appropriately combining the above-mentioned usage amounts or addition amounts (mg / L) in the aqueous system. The preferred range of the usage ratio or blending ratio is preferably 3 to 50:30 to 3, and more preferably 5 to 20:20 to 5. Examples of such combinations include, but are not limited to, combinations of the aforementioned AA / AMPS polymers and / or the aforementioned AA / HAPS polymers with MA homopolymers and / or MA / IB polymers.

[0111] The amount of the aqueous anticorrosive organic acid compound used or added (mg solid / L, hereinafter referred to as "mg / L") is not particularly limited, but is preferably 1 mg / L or more, more preferably 2 mg / L or more, further preferably 3 mg or 4 mg / L or more, further preferably 5 mg / L or more, further preferably 6 mg / L or more, further preferably 7 mg / L or more, further preferably 8 mg / L or more. The preferred upper limit is not particularly limited, but is preferably 100 mg / L or less, more preferably 50 mg / L or less, further preferably 40 mg / L or less, further preferably 30 mg / L or less, further preferably 20 mg / L or less, from the viewpoint of environmental load and cost reduction.

[0112] The amount of aqueous iminodiamalic acid used or added (mg solid / L, hereinafter referred to as "mg / L") is not particularly limited, and the preferred lower limit and upper limit of the amount of the aforementioned anticorrosive organic acid compound used, etc., can be appropriately adopted. As a more preferred numerical range, 3 to 50 mg / L is more preferred, and 5 to 20 mg / L is further preferred.

[0113] When the aforementioned polymer and the aforementioned anticorrosive organic acid compound are used in combination for an aqueous system, their usage ratio in the aqueous system or their blending ratio in the agent is not particularly limited, and can be obtained by appropriately combining the usage amount or addition amount (mg / L) of the aforementioned polymer and the aforementioned anticorrosive organic acid compound in the aqueous system. The preferred range of the usage ratio or blending ratio is preferably 3 to 50:30 to 3, more preferably 3 to 20:20 to 3, and further preferably 3 to 10:10 to 3. Examples of combinations of the aforementioned polymer and the aforementioned anticorrosive organic acid compound to which such a preferred usage ratio or blending ratio can be applied are not particularly limited, and as preferred combinations, a combination of a (meth) acrylic acid polymer having a sulfonic group (preferably the aforementioned AA / AMPS polymer and / or the aforementioned AA / HAPS polymer) and an anticorrosive organic acid compound (preferably iminodiamalic acid) can be cited; a combination of a maleic acid polymer (preferably an MA homopolymer and / or an MA / IB polymer) and an anticorrosive organic acid compound (preferably iminodiamalic acid) can be cited.

[0114] When the aforementioned (meth)acrylic acid polymer, the aforementioned dicarboxylic acid polymer and the aforementioned anticorrosive organic acid compound are used in combination for an aqueous system, the ratio of use of these polymers in the aqueous system or the ratio of blending in the agent is not particularly limited, and can be obtained by appropriately combining the aforementioned (meth)acrylic acid polymer: the aforementioned dicarboxylic acid polymer: the aforementioned anticorrosive organic acid compound in the aqueous system. The preferred range of the usage ratio or blending ratio is preferably 3 to 50: 3 to 50: 3 to 50: 3 to 50, more preferably 3 to 20: 3 to 20: 3 to 20, and further preferably 3 to 10: 3 to 10: 3 to 10. Examples of these combinations to which such a preferred usage ratio or blending ratio can be applied are not particularly limited, and as a preferred combination, a combination of a (meth)acrylic acid polymer having a sulfonic group (preferably the aforementioned AA / AMPS polymer and / or the aforementioned AA / HAPS polymer): a maleic acid polymer (preferably an MA homopolymer and / or an MA / IB polymer): an anticorrosive organic acid compound (preferably iminodiamalic acid) can be cited.

[0115] <Optional Ingredients>

[0116] In this embodiment, in addition to the aforementioned polymer and the aforementioned anticorrosive organic acid compound, any component can be appropriately used in the water system or included in the agent within the scope of not impairing the effect of the present invention. As the arbitrary component, there is no particular limitation, for example, one or more selected from pH adjusters, defoamers, corrosion inhibitors, antiscalants, bactericides, algaecides, etc. can be used.

[0117] In the present embodiment, in the water system, in addition to the above-mentioned polymer and the above-mentioned anticorrosive organic acid compound, a corrosion inhibitor other than them or unused can be further used. As such a corrosion inhibitor, for example, organic acid compounds, (meth) acrylic acid polymers and salts thereof, dicarboxylic acid polymers and salts thereof, polyaspartic acid and salts thereof, polyitaconic acid and salts thereof, amine compounds and amino acid compounds, etc. can be listed, and one or more selected from them can be used. It should be noted that in the present embodiment, from the viewpoint of reducing environmental load, it is preferred that phosphorus compounds and / or metal salt compounds (mg solid / L) are not added to the water system as a pharmaceutical component, for example, preferably not adding more than 1 mg / L, more preferably not adding more than 0.5 mg / L, further preferably not adding substantially, for example, not adding more than 0.1 or 0.05 mg / L, more preferably not adding more than 0 mg / L (that is, not adding at all as a pharmaceutical component), and further, from the viewpoint of reducing environmental load, it is very preferred that phosphorus compounds and / or metal salt compounds (non-phosphorus system and / or non-metal system) are not included or detected in the water system. The phosphorus concentration can be determined by the molybdenum blue (ascorbic acid reduction) method (JIS K 010246.1.1). The metal salt compound can be measured by IPC analysis.

[0118] In this embodiment, in addition to the above-mentioned combination of the aforementioned polymer and the aforementioned anticorrosive organic acid compound, there may be further an anti-scaling agent other than these or unused. Examples of the anti-scaling agent include (meth) acrylic acid polymers and salts thereof, dicarboxylic acid polymers and salts thereof, polyaspartic acid and salts thereof, and one or more of these may be used.

[0119] In addition, in the present embodiment, in addition to the aforementioned polymer and the aforementioned anticorrosive organic acid compound used in combination, there may be further a slime control agent other than these or unused. The slime control agent is not particularly limited, and examples thereof include hypochlorous acid and its salts, chlorine gas, hypobromous acid and its salts, combined halogen compounds (stabilized chlorine, stabilized bromine, etc.), organic bactericides, etc., and one or more selected from these can be used.

[0120] 1-5. Water-based metal corrosion protection methods

[0121] As described above, the aqueous metal corrosion protection treatment method in the present embodiment can be used in combination with the aforementioned polymer and the aforementioned corrosion-resistant organic acid compound, preferably these two or three components are present in the aqueous system at the same time. As the aforementioned polymer at this time, it is preferably a (meth) acrylic polymer having a sulfonic group, and more preferably a combination of a (meth) acrylic polymer having a sulfonic group and a dicarboxylic acid polymer.

[0122] In addition, the present embodiment can also add these components to the water system continuously or intermittently. The present embodiment can add these components to the water system at the same time or at different times. The water system can be equipped with one or more dosing devices for adding agents (components) to the water system. The dosing device can add each single component, a mixture of two components and other components, or a mixture of three components to the water system in the same period or at different times in a manner that these two components or three components exist in the water system at the same time. In addition, in the present embodiment, as places for mixing these components, tanks (such as grooves (pit) etc.) such as the flow path (such as circulating water path) of the water system, the inside of the pipe, etc., which can be equipped in the water system, such as the drug storage tank or the drug mixing tank, etc., can be listed, but are not limited to these. In addition, in the water system, it is also possible to appropriately have a measuring device capable of measuring the concentration of each agent (concentration of each component) in the water system, and a measuring device capable of measuring the water quality of the water system, etc. In the present embodiment, these measurement results may be sent to a control unit or the like, and the method of the present embodiment or its steps, actions, etc. may be controlled and managed by the control unit or the like.

[0123] The aqueous metal corrosion protection method of the present embodiment is as described above, and it is preferred that the aforementioned polymer (preferably a (meth) acrylic polymer having a sulfonic group) and the aforementioned anticorrosive organic acid compound, or the aforementioned (meth) acrylic polymer having a sulfonic group, the aforementioned dicarboxylic acid polymer, and the aforementioned anticorrosive organic acid compound are present in the aqueous system at a predetermined mass usage ratio or mass content ratio.

[0124] In the present embodiment, the polymer (preferably a (meth)acrylic polymer having a sulfonic group) and the anticorrosive organic acid compound, or the (meth)acrylic polymer having a sulfonic group, the dicarboxylic acid polymer, and the anticorrosive organic acid compound can be added to an aqueous system as a one-component agent or as a multi-component agent.

[0125] As another scheme of the present embodiment, a water-based corrosion protection method can also be provided by adding a water treatment agent containing at least one of the aforementioned polymer (preferably a (meth)acrylic polymer having a sulfonic group) or the aforementioned anticorrosive organic acid compound to the water system so that the aforementioned polymer (preferably a (meth)acrylic polymer having a sulfonic group) and the aforementioned anticorrosive organic acid compound are present in the water system.

[0126] In other aspects of the present embodiment, as a more preferred embodiment, a water treatment agent containing at least any one of the aforementioned (meth)acrylic acid polymer having a sulfonic group, the aforementioned dicarboxylic acid polymer, or the aforementioned anticorrosive organic acid compound is added to the water system, so that three components of the aforementioned (meth)acrylic acid polymer having a sulfonic group, the aforementioned dicarboxylic acid polymer, and the aforementioned anticorrosive organic acid compound are present in the water system, and an anticorrosive technology for the water system can also be provided.

[0127] In the case of an aqueous system, when the aforementioned polymer (preferably a (meth)acrylic acid polymer having a sulfonic group) and the aforementioned anticorrosive organic acid compound are used in combination, or when the aforementioned (meth)acrylic acid polymer having a sulfonic group and the aforementioned dicarboxylic acid polymer and the aforementioned anticorrosive organic acid compound are used in combination, these two or three components may be added at the same time or at different times so that these two or three components are present in the aqueous system, and these two or three components may be added continuously or intermittently.

[0128] In this embodiment, as a more preferred embodiment, a water-based metal corrosion treatment method using the following (i) metal corrosion treatment agent, (ii) water treatment agent, or (iii) water treatment agent for metal corrosion or a combination product of a water treatment agent can also be provided. The combination product in this specification can be a package product or a kit product.

[0129] (i) A metal corrosion inhibitor comprising the aforementioned polymer (preferably a (meth)acrylic acid polymer having a sulfonic group) and the aforementioned corrosion-inhibiting organic acid compound. The metal corrosion inhibitor preferably further comprises a dicarboxylic acid polymer.

[0130] (ii) A water treatment agent comprising at least the aforementioned polymer (preferably a (meth)acrylic polymer having a sulfonic group) and / or the aforementioned anticorrosive organic acid compound, and for use in an aqueous system, for strengthening, enhancing or improving metal corrosion protection achieved by the aforementioned polymer by at least using the aforementioned polymer (preferably a (meth)acrylic polymer having a sulfonic group) and the aforementioned anticorrosive organic acid compound in combination.

[0131] (iii) A water treatment agent for metal corrosion protection, which contains at least any one of the aforementioned (meth)acrylic acid polymer having a sulfonic group, the aforementioned dicarboxylic acid polymer, or the aforementioned anticorrosive organic acid compound, and when used for water-based metal corrosion protection, is used for combining the aforementioned (meth)acrylic acid polymer having a sulfonic group, the aforementioned dicarboxylic acid polymer, and the aforementioned anticorrosive organic acid compound for the water system. The water treatment agent may be a combination product for water treatment agents consisting of at least one, two, or three selected from a first water treatment agent containing the (meth)acrylic acid polymer having a sulfonic group, a second water treatment agent containing the dicarboxylic acid polymer, and a third water treatment agent containing the anticorrosive organic acid compound. The combination product in this specification may be a package product or a kit product.

[0132] The water system to which the present embodiment is applied is not particularly limited, and examples thereof include cooling water system, warm water system, membrane water system (e.g., reverse osmosis membrane (RO) water system), pulp process water system, scrubber water system, etc. In the present embodiment, as long as the water quality is that of a general water system (preferably a cooling water system), the anti-corrosion effect can be fully exerted.

[0133] This embodiment has an excellent feature that it can be applied to water with a wide range of hardness, from high hardness to low hardness. In this embodiment, the corrosion prevention effect can be fully exerted as long as the water quality is a general cooling water system.

[0134] In addition, in this embodiment, even if phosphorus compounds are not used as metal corrosion inhibitors, the corrosion protection effect can be fully exerted. Therefore, it can also be applied to the drainage standards of phosphorus concentrations in various countries. For example, the phosphorus concentration described in the above-mentioned addition amount of phosphorus compounds can be appropriately adopted. For example, as a condition of the water quality of the water system, the phosphorus concentration can be preferably less than 0.5 mg / L as P, and more preferably less than 0.1 mg / L as P.

[0135] As a condition of water quality, calcium hardness (mg / L as CaCO 3 , hereinafter also referred to as "mg / L") is not particularly limited. In the present embodiment, not only high hardness but also low hardness can obtain corrosion protection effect. The preferred upper limit is not particularly limited, for example, 1000 mg / L or less, preferably 800 mg / L or less, more preferably 700 mg / L or less, more preferably 600 mg / L or less. In addition, as a preferred lower limit, it is preferably 25 mg / L or more, more preferably 50 mg / L or more, further preferably 80 mg / L or more, more preferably 100 mg / L or more, more preferably 130 mg / L or 150 mg / L or more. As a preferred numerical range, it is preferably 50 to 1000 mg / L. The method for obtaining calcium hardness can be carried out according to JIS K0101 industrial water test method.

[0136] As the water quality conditions of the water system, M alkalinity (acid consumption (pH 4.8): (mg / L as CaCO 3 The acid consumption (PH 4.8) is not particularly limited, but is preferably 10 to 1000 mg / L, more preferably 25 to 500 mg / L, and still more preferably 50 to 300 mg / L. The method for determining the acid consumption (PH 4.8) can be carried out in accordance with JIS K0101 Industrial Water Test Method.

[0137] As a condition of water quality of the water system, magnesium hardness is not particularly limited, but the upper limit is preferably 500 mg / L or less, more preferably 400 mg / L or less, further preferably 350 mg / L or less, and more preferably 300 mg / L or less. The method for determining magnesium hardness can be carried out according to JIS K0101 industrial water test method.

[0138] In addition, as a condition of water quality of the water system, the chloride ion concentration is not particularly limited, but is preferably 800 mg / L or less, more preferably 600 mg / L or less, further preferably 500 mg / L or less, more preferably 300 mg / L or less, and more preferably 100 mg / L or less. The method for determining the chloride ion concentration can be carried out according to JIS K0101 industrial water test method.

[0139] In addition, as the water quality condition of the water system, the sulfate ion concentration is not particularly limited, but is preferably 800 mg / L or less, more preferably 600 mg / L or less, further preferably 500 mg / L or less, more preferably 300 mg / L or less, and more preferably 100 mg / L or less. The sulfate ion concentration can be obtained according to JIS K0101 industrial water test method.

[0140] The silica concentration of the water quality condition is not particularly limited, but is preferably 5 to 250 mg / L, more preferably 10 to 150 mg / L, and even more preferably 15 to 100 mg / L. The silica concentration can be determined according to JIS K0101 Industrial Water Testing Method.

[0141] As the condition of the water quality of the water system, the preferred pH is preferably 6 to 11, more preferably 6.5 to 10, and further preferably 7 to 9. In addition, the water temperature of the water system is not particularly limited, and is preferably 0 to 100°C, more preferably 5 to 80°C, further preferably 10 to 60°C, and further preferably 10 to 40°C. In addition, as the lower limit of the water temperature of the water system, it is preferably 0°C or more, and more preferably 5°C or more. In addition, in this embodiment, as shown in the [Example] described later, there is an excellent advantage that even if there is a place where the water system is partially in a high temperature state such as a heat exchanger, a heat exchange device, and its piping, it is possible to suppress or prevent scale in the part or place in the high temperature state. At this time, as a high temperature state that can be well dealt with, it is not particularly limited, and as a preferred upper limit, for example, it is 150°C or less, preferably 130°C or less, further preferably 120°C or less, more preferably 100°C or less, further preferably 80°C or less, further preferably 60°C or less, and further preferably 40°C or less.

[0142] As a preferred aspect of the present embodiment, it is preferably applied to a water system using metal materials that are easily corroded by water in various locations (for example, a heat exchanger, piping, etc.).

[0143] In addition, as a preferred mode of this embodiment, it can be expected to prevent scale in the heat transfer surface (heat exchanger, flow path for heat exchange, piping, heat exchange mechanism including them, etc.), which helps to maintain the concentration of the anticorrosive agent in the water system including the heat transfer surface, so it is preferably applied to the water system including the heat transfer surface. As a more preferred mode of this embodiment, it is more preferably a cooling water system, and it is further preferably applied to a circulating cooling water system. According to this embodiment, the anticorrosion effect achieved by the anticorrosion treatment method of this embodiment can be fully utilized.

[0144] The method of the present embodiment can also be realized by a control unit including a CPU etc. in a device (such as a computer, PLC, server, cloud service, etc.) for managing the above-mentioned metal corrosion protection treatment, the cooling water system described later, etc. In addition, the method of the present embodiment can also be stored as a program in a hardware resource having a recording medium (non-volatile memory (USB memory, etc.), SSD, HDD, CD, DVD, Blu-ray disc, etc.), and realized by the aforementioned control unit. The recording medium is preferably a computer-readable recording medium. It is also possible to provide a device having the control unit or the system by the control unit, a metal corrosion protection treatment system controlled by the control unit, in a manner of adding a reagent to the water system, etc. In addition, in the management device, as a component of the computer, at least a CPU is provided, and input units such as keyboards, communication units such as networks, display units such as displays, storage units such as HDDs, ROM, RAM, etc. can be listed, and one or more than two kinds can be selected from them. Among them, it is preferably provided with a RAM, a storage unit, a display unit and an input unit, and each selected component is connected, for example, by a bus as a transmission path for data.

[0145] <Cooling Water System>

[0146] The cooling water system used in the present embodiment is not particularly limited, but is preferably a system for circulating cooling water used for the operation of heat exchangers, etc. in air conditioning equipment of buildings, regional facilities, etc., and factories, etc. In addition, the cooling water system may be any of a once-through type, an open circulation type, or a closed circulation type.

[0147] In the present embodiment, by applying to a circulating cooling water system, an excellent corrosion prevention effect can be exhibited in the circulating cooling water system.

[0148] The circulating cooling water system is not particularly limited, and is preferably a water system equipped with a cooling tower in the system, such as an air conditioner, a petrochemical complex, a general factory, etc. The circulating cooling water system is preferably configured to indirectly cool the heat source generated in these air conditioners, general factories, etc., and may also be a general water system configured to include a heat exchanger, a circulating water circuit, and a cooling tower.

[0149] The type of circulating cooling water system is not particularly limited, and may be either an open circulating cooling water system or a closed circulating cooling water system. The open circulating cooling water system preferably has a structure in which the cooling water can circulate in an open manner, and the closed circulating cooling water system preferably has a structure in which the cooling water can circulate in a closed manner.

[0150] In addition, the metal corrosion treatment method for the cooling water system in the present embodiment (more specifically, the metal corrosion treatment method for the metal components in the cooling water system) preferably has at least a step of adding the aforementioned polymer and the aforementioned anticorrosive organic acid compound to the cooling water system and contacting them with the aforementioned metal components. It should be noted that at this time, (i) the aforementioned polymer and the aforementioned anticorrosive organic acid compound, or (ii) the aforementioned (meth) acrylic polymer having a sulfonic group, the aforementioned dicarboxylic acid polymer and the aforementioned anticorrosive organic acid compound can be added as a metal corrosion treatment agent as a one-liquid agent, or can be added as a combination product for a metal corrosion treatment agent as a multi-liquid agent. It should be noted that for the cooling water system, one or more of the aforementioned polymers and the aforementioned anticorrosive organic acid compound can be added at the same time or at different times, preferably in a manner that these two components or more than three components are present in the water system together, and the period during which these two components or more than three components are present in the water system together is not particularly limited, and can be any of continuous or intermittent.

[0151] In addition, the place where the agent is added is not particularly limited, and it can be any place in the cooling water system, and examples thereof include a sprinkler unit, a groove, a make-up water supply unit, a drug injection unit, a circulating water circuit, a delivery pump, a heat exchanger, etc., preferably a make-up water supply unit, a drug injection unit, a circulating water circuit, a delivery pump, etc., and can be added at a place selected from one or more of them. These two or more components are added in a manner that can exist in any place in the water system, thereby being able to obtain a better anti-corrosion effect for metal materials in contact with water downstream thereof. In addition, in the case of all or part of the circulation of the water system, these two or more components are mixed through the circulation of the water system, and a better anti-corrosion effect for metal materials in contact with water in the water system can be obtained.

[0152] As described above, according to the metal corrosion protection method of the present embodiment, it is possible to impart an excellent corrosion protection effect to a metal member that comes into contact with water.

[0153] Reference Figure 1 A metal corrosion protection method for an open circulation cooling water system 1 as an example of the present embodiment is described, but the present embodiment is not limited thereto. Hereinafter, a metal corrosion protection treatment using the aforementioned polymer and the aforementioned corrosion-resistant organic acid compound is described, and as a preferred embodiment of these components, for example, the aforementioned (meth) acrylic polymer having a sulfonic group, the aforementioned dicarboxylic acid polymer, and the aforementioned corrosion-resistant organic acid compound can be cited as described above.

[0154] In the open circulation cooling water system 1, water containing one or more of the aforementioned polymers and the aforementioned anti-corrosion organic acid compound is transported from the groove 15 to the heat exchanger 30 through the circulation water path 20 by the transport pump 21, and returns to the open cooling tower 10 through the circulation water path 20 via the heat exchanger 30. In the cooling tower 10, the water containing the aforementioned polymer and the aforementioned anti-corrosion organic acid compound is stored in the groove 15 through the sprinkler unit 12 and the filling material area 13, and is transported to the circulation water path 20 again by the pump 21. According to this embodiment, in this cycle, the anti-corrosion effect can be continuously maintained for the cooling water system. Through this cycle, the one or more of the aforementioned polymers and the aforementioned anti-corrosion organic acid compound present in the water of the water system can contact the metal components, and can exert an anti-corrosion effect on the metal components. It should be noted that it is preferred that one or more of the aforementioned polymers and the aforementioned corrosion-resistant organic acid compound are added to the water system using a dosing device capable of adding these two components or a mixture of three or more components separately, so that these two components or three or more components exist together in the water system. In addition, the addition amount of each component can also be adjusted in such a way that each of these components reaches a predetermined concentration range in the water system.

[0155] One or more of the aforementioned polymers and the aforementioned anticorrosive organic acid compound can be transported to the groove 15 at the same time or at different times by one or more reagent injection units 17, and the two can be mixed in the piping during the transport, or the two can be mixed in the groove 15. In addition, the reagent injection unit 17 can have one or more, for example, a plurality of different reagent injection units can be provided for using the aforementioned one or more polymers and the aforementioned anticorrosive organic acid compound, respectively, or a reagent injection unit for adding a one-liquid type reagent containing them to the water system or mixing these components can be provided. Water that is insufficient due to evaporation or the like is supplied to the groove 15 by the replenishment water supply unit 16 as needed, and the flow path for supplying the replenishment water to the groove 15 can also be constructed in a manner that one or more reagents from the reagent injection unit 17 can be added. It should be noted that by using the external air discharge of the air supply unit 11, the air used for cooling is discharged from the vent (louver) 18 through 13 and 12 from 11.

[0156] It should be noted that in the description of the examples of the aqueous metal corrosion protection treatment method of the present embodiment, the descriptions of the aforementioned polymers (e.g., the aforementioned (meth)acrylic polymers having a sulfonic group, the aforementioned dicarboxylic acid polymers), the aforementioned anti-corrosion organic acid compounds, their usage concentrations, usage ratios, and the aqueous metal corrosion protection treatment, aqueous metal corrosion protection treatment management, aqueous metal corrosion protection system, aqueous metal corrosion protection method, etc., which are the same or repeated in the contents described later (e.g., "2." to "3.", etc.), the descriptions of the various technical features, structures, definitions, terms, treatment methods, various units, etc., are appropriately omitted, but the descriptions of "1." to "3.", etc. are also applicable to any of the embodiments and can be appropriately adopted in each embodiment.

[0157] 2. Metal anticorrosive agent etc. of this embodiment

[0158] In the description of the examples of the metal corrosion inhibitor, water treatment agent, combination product for water treatment agent, etc. of the present embodiment, the description of the aforementioned polymers (for example, the aforementioned (meth)acrylic polymer having a sulfonic group, the aforementioned dicarboxylic acid polymer), the aforementioned corrosion-resistant organic acid compound, their usage concentrations, usage ratios, and the aqueous metal corrosion treatment, aqueous metal corrosion treatment management, aqueous metal corrosion treatment system, aqueous metal corrosion treatment method, etc., which are the same as or repeated in the above contents (for example, "1.") and the contents described later (for example, "3.", etc.), the descriptions of the various technical features, structures, definitions, terms, treatment methods, various units, etc., are appropriately omitted, but the descriptions of "1." to "3.", etc. are also applicable to any of the embodiments and can be appropriately adopted in each embodiment.

[0159] In this embodiment, by using the aforementioned polymer (preferably the aforementioned (meth) acrylic polymer having a sulfonic group and / or the aforementioned dicarboxylic acid polymer) and the aforementioned anticorrosive organic acid compound for water systems, it is possible to exert a very excellent anticorrosive effect on metals in contact with water in water systems. That is, the combination of the aforementioned polymer and the aforementioned anticorrosive organic acid compound can be contained or used as an effective component of a water-based anticorrosive composition, a water-based metal anticorrosive agent, a water treatment agent, a pharmaceutical agent, etc. It should be noted that in this embodiment, the composition can be an agent, and the agent can be a composition.

[0160] In this embodiment, the aforementioned polymer (preferably the aforementioned (meth)acrylic polymer having a sulfonic group and / or the aforementioned dicarboxylic acid polymer) and the aforementioned anticorrosive organic acid compound, or a mixture thereof can be used to manufacture a composition, the aforementioned water-based metal corrosion inhibitor, a combination product for a water treatment agent, and the like.

[0161] In addition, the present embodiment can also provide the aforementioned polymer (preferably the aforementioned (meth)acrylic polymer having a sulfonic group and / or the aforementioned dicarboxylic acid polymer) and the aforementioned corrosion-resistant organic acid compound, or a mixture thereof or use thereof for or in the aforementioned aqueous metal corrosion protection.

[0162] In addition, the present embodiment can also provide an aqueous metal corrosion protection method and an aqueous metal corrosion protection treatment method using the aforementioned polymer (preferably the aforementioned (meth)acrylic polymer having a sulfonic group and / or the aforementioned dicarboxylic acid polymer) and the aforementioned anticorrosive organic acid compound, or the mixture, or an aqueous metal corrosion inhibitor, a water treatment agent, a combination product for a water treatment agent, etc.

[0163] In addition, the present embodiment can provide a metal corrosion inhibitor comprising the polymer (preferably the (meth)acrylic polymer having a sulfonic group and / or the dicarboxylic acid polymer) and the corrosion-resistant organic acid compound.

[0164] In addition, the present embodiment can also provide a water treatment agent for metal corrosion protection, which contains at least any one of the aforementioned polymer (preferably the aforementioned (meth) acrylic polymer having a sulfonic group and / or the aforementioned dicarboxylic acid polymer) or the aforementioned anticorrosive organic acid compound, and when used for water-based metal corrosion protection, is used for combining the aforementioned polymer (preferably the aforementioned (meth) acrylic polymer having a sulfonic group and / or the aforementioned dicarboxylic acid polymer) and the aforementioned anticorrosive organic acid compound for the water system. The water treatment agent may be a combined product for water treatment agents consisting of at least one, two, or three selected from a first water treatment agent containing the aforementioned (meth) acrylic polymer having a sulfonic group, a second water treatment agent containing the aforementioned dicarboxylic acid polymer, and a third water treatment agent containing the aforementioned anticorrosive organic acid compound.

[0165] As another scheme of the present embodiment, a water treatment agent can also be provided, which contains the aforementioned polymer (preferably the aforementioned (meth) acrylic polymer having a sulfonic group) and / or the aforementioned dicarboxylic acid polymer, and / or the aforementioned anti-corrosion organic acid compound, and when used in an aqueous system, is used to strengthen, enhance or improve metal corrosion protection achieved by using the aforementioned polymer (preferably the aforementioned (meth) acrylic polymer having a sulfonic group and / or the aforementioned dicarboxylic acid polymer) and the aforementioned anti-corrosion organic acid compound in combination.

[0166] In addition, as another aspect of the present embodiment, it is also possible to provide the use of the aforementioned polymer (preferably the aforementioned (meth)acrylic polymer having a sulfonic group and / or the aforementioned dicarboxylic acid polymer) and the aforementioned corrosion-resistant organic acid compound, or one or more thereof in the manufacture of the aforementioned agent etc., for use in the manufacture of the aforementioned agent etc., or for use in the manufacture or in the use thereof.

[0167] Furthermore, as another aspect of the present embodiment, it is also possible to provide an aqueous corrosion protection method for suppressing corrosion of metal in contact with water using the above-mentioned agent or the like.

[0168] The aforementioned polymer is preferably a water-soluble organic polymer, and more preferably the aforementioned (meth)acrylic polymer having a sulfonic group and / or the aforementioned dicarboxylic acid polymer. Among the aforementioned (meth)acrylic polymer having a sulfonic group, a copolymer of a (meth)acrylic monomer and a sulfonic group-containing monomer is more preferred, and a copolymer of a (meth)acrylic monomer and a monomer containing an amide group or a hydroxyl group and a sulfonic group is further preferred. Among the aforementioned dicarboxylic acid polymers, a maleic acid polymer is more preferred, and polymaleic acid and a maleic acid copolymer are further preferred.

[0169] The (meth)acrylic polymer is preferably a (meth)acrylic polymer containing a sulfonic group, and the molar ratio of the (meth)acrylic monomer to the sulfonic acid monomer in the polymer is preferably 75:25 to 93:7. Among the (meth)acrylic polymers, AA / AMPS polymers and / or AA / HAPS polymers are preferred.

[0170] The dicarboxylic acid polymer is preferably a maleic acid polymer, and the molar ratio of the maleic acid monomer to the other monomers having an unsaturated bond is preferably 50 or more: less than 50. Among the maleic acid polymers, polymaleic acid and / or MA / butene (preferably IB) polymers are used.

[0171] The corrosion-resistant organic acid compound is preferably one or more selected from citric acid, tartaric acid, mucic acid, glucoheptonic acid, butanetetracarboxylic acid, iminodiamalic acid, and 3-hydroxy-2,2′-iminodisuccinic acid, and among them, iminodiamalic acid is preferred.

[0172] The ratio of the polymer (preferably a (meth)acrylic acid polymer and / or a dicarboxylic acid polymer having a sulfonic group) to the anticorrosive organic acid compound in the water system or in the medicine is preferably 3 to 50:3 to 50. In addition, the ratio of the (meth)acrylic acid polymer having a sulfonic group to the dicarboxylic acid polymer in the water system or in the medicine is preferably 3 to 50:3 to 50. In addition, the ratio of the (meth)acrylic acid polymer: the dicarboxylic acid polymer: the anticorrosive organic acid compound in the water system or in the medicine is preferably 3 to 50:3 to 50:3 to 50.

[0173] 3. This technology may also adopt the following technical features, structures or other solutions.

[0174] ·[1] A method for preventing metal corrosion in an aqueous system, which uses: a copolymer of a (meth)acrylic acid monomer and a sulfonic acid-containing monomer, and a corrosion-inhibiting organic acid compound having an organic acid corrosion inhibition effect index of 4 or more.

[0175] ·[2] The aqueous system method according to the foregoing [1], which further uses a dicarboxylic acid-based polymer.

[0176] ·[3] A method for preventing metal corrosion in an aqueous system, which uses: a copolymer of a (meth)acrylic acid monomer and a sulfonic acid-containing monomer, a dicarboxylic acid-based polymer, and a corrosion-inhibiting organic acid compound having an organic acid corrosion inhibition effect index of 4 or more.

[0177] ·[4] The method according to any one of the foregoing [1] to [3], which is an aqueous corrosion prevention method for inhibiting the corrosion of metal in contact with an aqueous system.

[0178] ·[5] An aqueous metal corrosion inhibitor, which contains: a copolymer of a (meth)acrylic acid monomer and a sulfonic acid-containing monomer, and a corrosion-inhibiting organic acid compound having an organic acid corrosion inhibition effect index of 4 or more.

[0179] ·[6] An aqueous metal corrosion inhibitor, which contains: (A) a copolymer of a (meth)acrylic acid monomer and a sulfonic acid-containing monomer, (B) a dicarboxylic acid-based polymer, and (C) a corrosion-inhibiting organic acid compound having an organic acid corrosion inhibition effect index of 4 or more.

[0180] ·[7] A water treatment agent, which contains at least any one of: (A) a copolymer of a (meth)acrylic acid monomer and a sulfonic acid-containing monomer, (B) a dicarboxylic acid-based polymer, or (C) a corrosion-inhibiting organic acid compound having an organic acid corrosion inhibition effect index of 4 or more, and is used in a combination of (i) the foregoing (A) and the foregoing (C), or (ii) the foregoing (B) and the foregoing (C), or (iii) the combination of the foregoing (A) to (C) when used for preventing metal corrosion in an aqueous system.

[0181] ·[8] A water treatment agent for improving the prevention of metal corrosion in an aqueous system, which contains a corrosion-inhibiting organic acid compound having an organic acid corrosion inhibition effect index of 4 or more, and improves the prevention of metal corrosion in an aqueous system by means of the foregoing corrosion-inhibiting organic acid compound, using (i) a copolymer of a (meth)acrylic acid monomer and a sulfonic acid-containing monomer, or (ii) a dicarboxylic acid-based polymer, or (iii) a copolymer of a (meth)acrylic acid monomer and a sulfonic acid-containing monomer and a dicarboxylic acid-based polymer.

[0182] [9] A method for improving water-based metal corrosion protection, which uses an organic acid compound having an organic acid corrosion protection effect index of 4 or more, and improves water-based metal corrosion protection by using (A) a copolymer of a (meth)acrylic acid monomer and a sulfonic acid-containing monomer, or (B) a dicarboxylic acid polymer, or a copolymer of a (meth)acrylic acid monomer and a sulfonic acid-containing monomer and (B) a dicarboxylic acid polymer.

[0183]

[10] A component selected from (A) a copolymer of a (meth)acrylic acid monomer and a sulfonic acid-containing monomer, (B) a dicarboxylic acid polymer, and (C) an organic acid compound having an organic acid corrosion protection effect index of 4 or more, or a combination of two or three components, or use of one or more of these components in the manufacture of the agent described in any one of [5] to [8] above, or in the manufacture of the agent or for the purpose of manufacture.

[0184]

[11] A component selected from (A) a copolymer of a (meth) acrylic acid monomer and a sulfonic acid-containing monomer, (B) a dicarboxylic acid polymer, and (C) an organic acid compound having an organic acid corrosion protection effect index of 4 or more, or a combination of two or three components, or one or more of these components for use in aqueous metal corrosion protection treatment or for use in aqueous metal corrosion protection treatment.

[0185]

[12] A water-based metal corrosion protection method, wherein a component selected from (A) a copolymer of a (meth) acrylic acid monomer and a sulfonic acid-containing monomer, (B) a dicarboxylic acid polymer, and (C) an organic acid compound having an organic acid corrosion protection effect index of 4 or more, a combination of one or two or a combination of three is used in or added to the water-based system.

[0186]

[13] A method for strengthening, enhancing or improving water-based metal corrosion protection, which uses a corrosion-resistant organic acid compound having an organic acid corrosion protection effect index of 4 or more, and utilizes (i) a copolymer of a (meth)acrylic acid monomer and a sulfonic acid-containing monomer, or (ii) a dicarboxylic acid polymer, or (iii) a copolymer of a (meth)acrylic acid monomer and a sulfonic acid-containing monomer and a dicarboxylic acid polymer to strengthen, enhance or improve water-based metal corrosion protection.

[0187]

[14] An organic acid corrosion protection compound having an organic acid corrosion protection effect index of 4 or more for strengthening, enhancing or improving water-based metal corrosion protection using (i) a copolymer of a (meth)acrylic acid monomer and a sulfonic acid-containing monomer, or (ii) a dicarboxylic acid polymer, or (iii) a copolymer of a (meth)acrylic acid monomer and a sulfonic acid-containing monomer and a dicarboxylic acid polymer, or its use.

[0188]

[15] The copolymer of the (meth)acrylic acid monomer (preferably an acrylic acid monomer) and a sulfonic acid-containing monomer described in any one of [1] to

[14] is preferably a (meth)acrylic acid monomer and a monoethylenically unsaturated sulfonic acid monomer, or the sulfonic acid monomer is preferably a monomer having an amide group and a sulfonic group and / or a monomer having a hydroxyl group and a sulfonic group. The copolymer of the (meth)acrylic acid monomer and the sulfonic acid-containing monomer is further preferably one or more selected from the group consisting of AA / AMPS polymers and AA / HAPS polymers.

[0189]

[16] The dicarboxylic acid polymer described in any one of [1] to

[15] is preferably one or more selected from the group consisting of maleic acid polymers and polyepoxysuccinic acid. The maleic acid polymer is further preferably one or more selected from the group consisting of homopolymers of maleic acid monomers (polymaleic acid) and copolymers of maleic acid monomers and unsaturated hydrocarbon monomers (preferably isobutylene monomers). The dicarboxylic acid polymer is further preferably one or more selected from the group consisting of MA polymers (polymaleic acid) and MA / butene (preferably IB) polymers.

[0190]

[17] The corrosion-resistant organic acid compound described in any one of [1] to

[16] is preferably an organic acid compound having a carboxylic acid group. More preferably, the corrosion-resistant organic acid compound is an organic acid compound having a carboxylic acid group and a hydroxyl group. The corrosion-resistant organic acid compound is one or more selected from the group consisting of citric acid, tartaric acid, mucic acid, glucoheptonic acid, butanetetracarboxylic acid, iminodiamalic acid, and 3-hydroxy-2,2'-iminodisuccinic acid, and more preferably iminodiamalic acid.

[0191]

[18] The amount of the copolymer of the (meth)acrylic acid monomer and the sulfonic acid-containing monomer in the above-mentioned [1] to

[17] added to the water system is preferably 5 mg / L or more, and / or the amount of the dicarboxylic acid polymer added to the water system is preferably 5 mg / L or more, and / or the amount of the anticorrosive organic acid compound added to the water system is preferably 5 mg / L or more.

[0192]

[19] The copolymer of the (meth)acrylic acid monomer and the sulfonic acid-containing monomer in [1] to

[18] and the corrosion-resistant organic acid compound are preferably used in a ratio or blending ratio of 5 to 50:5 to 50.

[0193]

[20] The copolymer of the (meth)acrylic acid monomer and the sulfonic acid-containing monomer, the dicarboxylic acid polymer and the corrosion-resistant organic acid compound in [1] to

[19] are preferably used in a ratio or a blending ratio of 5 to 50:5 to 50:5 to 50.

[0194] Example

[0195] The following examples and comparative examples are given to explain the embodiments of the present invention. The examples described below are representative examples of the present invention, and the scope of the present invention is not to be construed narrowly.

[0196] <Raw materials>

[0197] The polymers shown in Tables 1 and 2 were used in the tests.

[0198] [Table 1]

[0199] Table 1 (Meth) acrylic polymers

[0200]

[0201] [Table 2]

[0202] Table 2 Dicarboxylic acid polymers

[0203]

[0204] <Test Example 1>

[0205] <Method>

[0206] In order to explore organic acids that show good anti-corrosion effects, a corrosion test was conducted. The operating conditions were a water temperature of 30°C, a test period of 3 days, and a rotation speed of 150rpm. Specifically, referring to "K0100: Industrial Corrosion Test Method", test water adjusted to the following water quality conditions was added to a beaker with a stirrer on the bottom, and then the suspended longitudinal strip test piece was completely immersed in the test water and arranged near the center of the beaker without contacting the stirrer, and the corrosion test was conducted.

[0207] The water quality condition was adjusted to 500mg / L calcium hardness as CaCO 3 , acid consumption (pH 4.8) 200mg / L as CaCO 3 , magnesium hardness 250 mg / L, chloride ion concentration 350 mg / L, sulfate ion concentration 500 mg / L, acrylic acid polymer 1 (AA polymer containing S) 10 mg / L, dicarboxylic acid polymer 1 (MA polymer 1) 5 mg / L, organic acid 50 mg / L, pH 8.6. The organic acids shown in Table 3 below were used.

[0208] The material used in the test was a test piece made of SPCC (30 mm wide × 50 mm long × 1 mm thick). One test piece was immersed in 1L of test water. The test results were evaluated as follows: the corrosion loss was calculated from the weight difference of the test piece before and after the test, based on the following formula (where the specific gravity is 7.87 g / cm 3) The corrosion rate (mm / y) is calculated. It should be noted that the material of SPCC (Steel Plate Cold Commercial: a type of cold rolled steel plate) is low carbon steel with a carbon content of 0.15% or less.

[0209] Formula 1

[0210]

[0211] In addition, as an index showing the corrosion prevention effect of the organic acid, the <Organic Acid Corrosion Prevention Effect Index> is determined by the following formula: The molecular weight (MW) of the organic acid is calculated from the total weight of atoms contained in the molecule.

[0212] Organic acid corrosion protection effect index = (total amount of oxygen atoms in the molecule / molecular weight) × (number of COOH groups in the molecule) × (sum of the number of COOH groups and OH groups in the molecule)

[0213] <Results>

[0214] When the organic acid corrosion protection index is less than 4, the corrosion rate is large, and when it is above 4, the corrosion rate is small. It can be seen that the organic acid corrosion protection index is 4, and the molecules with a larger organic acid corrosion protection index than it are good corrosion inhibitors. The organic acid group with an organic acid corrosion protection index of 4 or more is used as an anticorrosive organic acid compound. Among the organic acids used in Test Example 1, the organic acid corrosion protection index is 4 or more, and glucoheptonic acid, tartaric acid, citric acid, mucic acid, 1,2,3,4-butanetetracarboxylic acid, and iminodiamalic acid are confirmed, and they confirm excellent corrosion protection effects with a corrosion rate of less than 0.05. Furthermore, the corrosion rate of these organic acid compounds with an organic acid corrosion protection index of 4 or more is 0.01 to 0.02, which is very good. It can be seen that it is preferred to use one or more selected from them as an anticorrosive organic acid compound.

[0215] In addition, the maximum organic acid corrosion protection effect index in the corrosion-resistant organic acid compound is 14, but the upper limit of the organic acid corrosion protection effect index is not particularly limited, and the corrosion rate can be suppressed to below 0.02. In addition, the present inventors believe that organic acids having a hydroxyl group (OH group) and a carboxylic acid group (COOH group) exert good corrosion protection effects. In addition, it is known that the corrosion-resistant organic acid compound preferably has a hydroxyl group (OH group) and a carboxylic acid group (COOH group).

[0216] [Table 3]

[0217] Table 3 Anti-clockwise effect of organic acids

[0218]

[0219] <Test Example 2>

[0220] <Method>

[0221] Among the organic acids that showed good anticorrosion effects in Test Example 1, iminodiamalic acid was used to study the combination with (meth)acrylic acid polymers and dicarboxylic acid polymers. The operating conditions were water temperature 40°C, test period 3 days, and rotation speed 150 rpm. The water quality conditions of the test water were adjusted to a calcium hardness of 150 mg / L as CaCO 3 , acid consumption (pH 4.8) 65mg / Las CaCO 3 、Magnesium hardness 50mg / L as CaCO 3 , chloride ion concentration 75 mg / L, sulfate ion concentration 75 mg / L, pH 7.9.

[0222] The material used in the test was the same SPCC test piece (30 mm × 50 mm × 1 mm) as in the above-mentioned Test Example 1. One test piece was immersed in 1 L of test water, and the same corrosion test as in the above-mentioned Test Example 1 was performed. The test results were evaluated as follows: the corrosion loss was calculated from the weight difference of the test piece before and after the test, and the corrosion rate (mm / y) of the above-mentioned <Test Example 1> was calculated based on the formula (wherein the specific gravity is 7.87 g / cm 3 ), calculate the corrosion rate (mm / y).

[0223] <Results>

[0224] When AA polymer 1, MA polymer 1, and iminodiamalic acid are used alone, good corrosion protection effect cannot be obtained (Comparative Example 2). On the contrary, when AA polymer 1 and iminodiamalic acid are used in combination, improvement of corrosion protection effect is found (Example 1). Furthermore, the corrosion protection effect when MA polymer 1 is added and used in combination with the three agents is the most excellent (Example 2). As a result, it is believed that a better corrosion protection effect can be exerted by a combination of a (meth) acrylic polymer having a sulfonic group (preferably an acrylic polymer having a sulfonic group) and an anticorrosive organic acid compound, and a combination of a dicarboxylic acid polymer and an anticorrosive organic acid compound. It is further believed that a very excellent corrosion protection effect can be further exerted by the combination of these three components, a (meth) acrylic polymer having a sulfonic group, a dicarboxylic acid polymer, and an anticorrosive organic acid compound.

[0225] [Table 4]

[0226] Table 4 Evaluation of the anti-corrosion effect of the combination

[0227]

[0228] <Test Example 3>

[0229] <Method>

[0230] The anticorrosion effect of the combination of the (meth)acrylic acid polymer, the dicarboxylic acid polymer, and the organic acid was evaluated under water conditions different from those in Test Example 2. In Test Example 3, the same corrosion test as in Test Example 1 was performed.

[0231] The operating conditions were water temperature 30°C, test period 3 days, and rotation speed 150 rpm. The water quality conditions were adjusted to calcium hardness 530 mg / Las CaCO 3 , acid consumption (pH 4.8) 225mg / L as CaCO 3 、Magnesium hardness 165mg / Las CaCO 3 , chloride ion concentration 260mg / L, sulfate ion concentration 270mg / L, pH 8.6. The material used in the test is the same SPCC test piece (30mm×50mm×1mm) as in the above-mentioned Test Example 1. One test piece was immersed in 1L of test water, and the same corrosion test as in the above-mentioned Test Example 1 was carried out. The test results were evaluated as follows: the corrosion loss was calculated from the weight difference of the test piece before and after the test, based on the formula for calculating the corrosion rate (mm / y) of the above-mentioned <Test Example 1> (wherein the specific gravity is 7.87g / cm 3 ), calculate the corrosion rate (mm / y).

[0232] <Results>

[0233] Compared with Test Example 2, there is a tendency for the corrosion rate to be lower as a whole, so it is believed that the water quality itself is corrosion-resistant. Among them, the combination of AA polymer 1, MA polymer 1 or MA polymer 2, and iminodiamalic acid (three components) shows a particularly good corrosion-resistant effect. This result means that even if the type of dicarboxylic acid polymer is changed, a good corrosion-resistant effect is exerted. In addition, it is believed that the combination of a (meth) acrylic acid polymer (preferably an acrylic acid polymer) having a sulfonic group, an anticorrosive organic acid compound, and a dicarboxylic acid polymer (preferably a maleic acid polymer) exerts a better corrosion-resistant effect.

[0234] [Table 5]

[0235] Table 5 Evaluation of the anti-corrosion effect of the combination

[0236]

[0237] <Test Example 4>

[0238] <Method>

[0239] In the combination of (meth)acrylic acid polymer, dicarboxylic acid polymer, and anticorrosive organic acid compound, it is believed that the (meth)acrylic acid polymer acts as a dispersant to maintain water quality and helps prevent scale. Therefore, the effect of the type of (meth)acrylic acid polymer on the prevention of precipitation in the test water was evaluated. The water quality of the test water was adjusted to a calcium hardness of 300 mg / Las CaCO 3 , pH 8.5, and immersed in a hot water bath at 90° C. for 1 hour. The turbidity of the aqueous solution after the test was confirmed.

[0240] <Results>

[0241] It was confirmed that the precipitation of test water was suppressed by using a (meth) acrylic polymer having a sulfonic group. It can be expected that by using a (meth) acrylic polymer having a sulfonic group, the scale prevention of the heat transfer surface is achieved, which helps to maintain the concentration of the corrosion inhibitor in the water system containing the heat transfer surface. The result shows that a better corrosion protection effect can be exerted by the combination of a (meth) acrylic polymer having a sulfonic group and an anticorrosive organic acid compound, and a better anti-scaling effect can also be exerted. It is further believed that a very excellent corrosion protection effect can be further exerted by the combination of these three components, a (meth) acrylic polymer having a sulfonic group, a dicarboxylic acid polymer (preferably a maleic acid polymer) and an anticorrosive organic acid compound, and a better anti-scaling effect can also be exerted.

[0242] [Table 6]

[0243] Table 6 Evaluation of the anti-scaling effect of (meth)acrylic acid polymers

[0244]

[0245] In addition, from the above results, it was found that in an aqueous system having a metal material or the like in contact with the aqueous system, by using the above-mentioned corrosion-resistant organic acid compound having an organic acid corrosion protection index of a predetermined value or higher and a polymer (particularly one polymer having (meth)acrylic acid and sulfonic acid as monomers, or two or more different polymers having (meth)acrylic acid and sulfonic acid as monomers and a dicarboxylic acid polymer), a more excellent corrosion protection effect can be synergistically exerted by these two or three components.

[0246] That is, it was found that in an aqueous system having a metal material in contact with the aqueous system, by using at least two components, a polymer having (meth)acrylic acid and sulfonic acid as monomers and an organic acid corrosion protection effect compound having an organic acid corrosion protection effect index of 4 or more, a better aqueous metal corrosion protection treatment effect and a better anti-scaling effect can be exerted. It was further found that by using three components, a polymer having (meth)acrylic acid and sulfonic acid as monomers, a dicarboxylic acid polymer, and an organic acid corrosion protection effect compound having an organic acid corrosion protection effect index of 4 or more, a very excellent aqueous metal corrosion protection treatment effect and a better anti-scaling effect can be exerted.

[0247] It has also been found that by using the above-mentioned corrosion inhibitory organic acid compound having an organic acid corrosion inhibitory index greater than or equal to a predetermined value for a polymer (particularly one polymer having (meth)acrylic acid and sulfonic acid as monomers, or two or more different polymers having (meth)acrylic acid and sulfonic acid as monomers and a dicarboxylic acid polymer), the corrosion inhibitory effect of the polymer can be synergistically enhanced or improved to a more excellent corrosion inhibitory effect.

[0248] In addition, regarding the anti-corrosion mechanism (hypothesis) of the present embodiment, the inventors of the present invention have conceived the following hypothesis, but there are still many unclear aspects, and the mechanism of action has been further studied. The inventors of the present invention believe that the aforementioned anti-corrosion organic acid compound contributes to the formation of anti-corrosion rust by acting on ions such as iron, thereby inhibiting the dissolution reaction of the metal in the corrosion reaction. The inventors of the present invention believe that the sulfonated (meth) acrylic acid polymer is appropriately maintained in a dispersed state and maintains the anti-corrosion effect in a manner that the calcium combination does not scale. The inventors of the present invention believe that the dicarboxylic acid polymer combines with calcium to form a film on the metal surface, thereby inhibiting the reduction reaction of oxygen in the corrosion reaction. The inventors of the present invention further believe that when the sulfonated (meth) acrylic acid polymer is used in combination with the dicarboxylic acid polymer, the sulfonated (meth) acrylic acid polymer is appropriately maintained in a dispersed state and maintains a better anti-corrosion effect in a manner that the dicarboxylic acid polymer and calcium combination does not scale.

[0249] As described above, the present inventors can provide an aqueous metal corrosion protection method using a copolymer of a (meth)acrylic acid monomer and a sulfonic acid-containing monomer and an organic acid corrosion protection effect index of 4 or more, and more preferably a dicarboxylic acid polymer. In addition, the present inventors can provide an aqueous metal corrosion protection method or an aqueous metal corrosion inhibitor using a copolymer of a (meth)acrylic acid monomer and a sulfonic acid-containing monomer, a dicarboxylic acid polymer, and an organic acid corrosion protection effect index of 4 or more.

[0250] Furthermore, since the above two or three components do not use phosphorus compounds and / or metal salt compounds, the present method or agent does not have the burden on the water environment such as eutrophication and water toxicity caused by phosphorus compounds and / or metal salt compounds, and the burden on the water environment as a whole can also be greatly reduced. Furthermore, the above two or three components exert good anti-corrosion effects under the water quality conditions of the test water, so if the water quality conditions of the test water are taken into consideration, the present method or agent can be applied in a wide range of water quality.

[0251] That is, the present inventors can also achieve the following purpose: provide a water system metal corrosion protection treatment method and water system metal corrosion inhibitor, which can exert the metal corrosion protection effect of the water system even without using phosphorus compounds and / or metal salt compounds that cause loads on the water environment such as eutrophication and water toxicity, and can be applied in a wide range of water quality. It should be noted that this method or this agent can also utilize phosphorus compounds and / or metal salt compounds in the water system while considering reducing the load on the water environment.

[0252] It should be noted that, in this specification, numbers or letters such as "first, second, third...", "A, B, C...", "1 time, 2 times, 3 times...", etc. are sometimes added for convenience of description, but the present invention is not narrowly limited to be interpreted as a sequence, etc., and the sequence can be changed arbitrarily. In addition, in this specification, for example, "manage (thing)" and "perform (thing)" can be regarded as methods, processes, means or steps, etc., and these terms can also be appropriately replaced. For example, "step" can be regarded as "perform (thing)", methods, processes or means, etc., "process" can be regarded as "perform (thing)", methods, steps or means, etc., and "means" can be regarded as "perform (thing)", methods, processes or steps, etc. In addition, in this specification, "system" can be set as a mechanism, device, unit or part, "mechanism" can be set as a system, device, unit or part, "device" can be set as a system, mechanism, unit or part, "unit" can be set as a mechanism, system, device or part, and "part" can be set as a mechanism, unit, device or system, or a mechanism, unit or device provided therein. A combination product can also be a combination.

[0253] Description of Reference Numerals

[0254] 1 open circulation cooling water system, 10 open cooling tower, 11 air supply unit, 12 sprinkler unit, 13 filling material area, 14 space, 15 groove, 16 supplementary water supply unit, 17 agent injection unit, 18 ventilation port, 20 circulation water circuit, 21 delivery pump, 30 heat exchanger.

Claims

1. A water-based metal corrosion protection method, using: Copolymers of (meth)acrylic acid monomers and sulfonic acid-containing monomers, and An anticorrosive organic acid compound having an organic acid anticorrosion effect index of 4 or more.

2. The method according to claim 1, further comprising using a dicarboxylic acid polymer.

3. The method according to claim 1 or 2, in, The corrosion-resistant organic acid compound is an organic acid compound having a carboxylic acid group.

4. The method according to claim 1 or 2, in, The corrosion-resistant organic acid compound is an organic acid compound having a carboxylic acid group and a hydroxyl group.

5. The method according to claim 1 or 2, in, The anti-corrosion organic acid compound is iminodiamalic acid.

6. The method according to claim 2, in, The dicarboxylic acid polymer is one or more selected from the group consisting of a maleic acid polymer and polyepoxysuccinic acid.

7. The method according to claim 1 or 2, which is an aqueous corrosion protection method for suppressing corrosion of metal in contact with an aqueous system.

8. A water-based metal corrosion protection agent, comprising: Copolymers of (meth)acrylic acid monomers and sulfonic acid-containing monomers, and An anticorrosive organic acid compound having an organic acid anticorrosion effect index of 4 or more.

9. A water-based metal corrosion protection agent, comprising: (A) a copolymer of a (meth)acrylic acid monomer and a sulfonic acid-containing monomer, (B) a dicarboxylic acid polymer, and (C) An anticorrosive organic acid compound having an organic acid anticorrosion effect index of 4 or more.

10. A water treatment agent comprising at least: (A) a copolymer of a (meth)acrylic acid monomer and a sulfonic acid-containing monomer, (B) a dicarboxylic acid polymer, or (C) Anticorrosion Organic Acid Compounds Having an Organic Acid Anticorrosion Effect Index of 4 or More Any of When used for aqueous metal corrosion protection, it is used as (i) a combination of (A) and (C) or (ii) a combination of (A) to (C).

11. A water treatment agent for improving metal corrosion protection in water systems, comprising an organic acid compound having an organic acid corrosion protection effect index of 4 or more, The aqueous metal corrosion protection treatment is improved by using (i) a copolymer of a (meth)acrylic acid monomer and a sulfonic acid-containing monomer, or (ii) a copolymer of a (meth)acrylic acid monomer and a sulfonic acid-containing monomer and a dicarboxylic acid-based polymer.

12. A method for improving metal corrosion protection in water, using an organic acid compound having an organic acid corrosion protection effect index of 4 or more, The aqueous metal corrosion protection treatment is improved by using (i) a copolymer of a (meth)acrylic acid monomer and a sulfonic acid-containing monomer, or (ii) a copolymer of a (meth)acrylic acid monomer and a sulfonic acid-containing monomer and a dicarboxylic acid-based polymer.

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