JP2021042326A - Electrolytic detergent and method for cleaning metal - Google Patents

Abstract

To provide an electrolytic detergent exhibiting excellent liquid-dispelling properties when cleaning a metal, and to provide a method for cleaning the metal using the same.SOLUTION: An electrolytic detergent comprises an alkali agent and a compound expressed by the following formula (1). [In the formula, A11O and A12O are each independently 2-3C alkyleneoxy group, the A11O and A12O being identical to or being different from each other; n1 and n2 exhibit an average addition molar number of the alkyleneoxy group and are an integer of 1-5; R11 is a 4-22C linear or branched, and saturated or unsaturated aliphatic hydrocarbon group; R12 is a 7-9C aralkyl group or a univalent organic group expressed by -(A13O)n3-H {wherein, A13O are a 2-3C alkyleneoxy group, the A13O being identical to or being different from each other, and n3 exhibits the average addition molar number of the alkyleneoxy group and are the integer of 1-5}; and X- is a univalent anion].SELECTED DRAWING: None

Description

The present invention relates to an electrolytic cleaning agent and a method for cleaning a metal.

In recent years, as the parts market for automobiles, trains, airplanes, machine tools, etc. has become globalized, low-priced parts have appeared on the market, and parts makers and material makers are exposed to fierce cost competition. For this reason, each company is taking various cost reductions in the manufacturing process of materials and parts in order to maintain its competitiveness.

As an example of cost reduction in the manufacturing process, the efficiency of the cleaning process of metal materials and metal parts is being promoted. Various cleaning agents are used for cleaning metal materials and metal parts. For example, in Patent Document 1 below, an anionic surfactant and / or a nonionic surfactant is used in order to improve the cleaning property. Further, an aqueous metal cleaning agent composition containing polyethyleneimine has been proposed.

Japanese Unexamined Patent Publication No. 8-31142

If the cleaning liquid remains on the materials and parts after cleaning in the cleaning process, dirt components will reattach and energy costs for drying the materials and parts will be incurred. It becomes important.

The present invention has been made in view of the above circumstances, and provides an electrolytic cleaning agent capable of exhibiting excellent liquid drainage in metal cleaning and a metal cleaning method using the electrolytic cleaning agent.

As a result of intensive research to solve the above problems, the present inventor has excellent liquid drainage by electrolytically cleaning a metal with a cleaning agent containing a specific quaternary ammonium salt and an alkaline agent. We have found that the property can be obtained, and have completed the present invention.

That is, the present invention provides an electrolytic cleaning agent containing an alkaline agent and a compound represented by the following general formula (1).

In the above formula ^{(1), A 11} O, and ^{A 12} O each independently represent an alkylene group having 2 or 3 carbon atoms, ^{A 11} O, and ^{A 12} O in which there are a plurality in the molecule, a same It may be different, and n1 and n2 indicate the average number of moles of the alkyleneoxy group added, which is an integer of 1 to 5, and R ¹¹ is a linear or branched saturation having 4 to 22 carbon atoms. Alternatively, it represents an unsaturated aliphatic hydrocarbon group, R ¹² represents an aralkyl group having 7 to 9 carbon atoms or a monovalent organic group represented by the following general formula (I), and X ⁻ represents a monovalent anion. Shown.
− (A ¹³ O) _n3 −H (I)
{In formula (I), A ¹³ O represents an alkyleneoxy group having 2 or 3 carbon atoms, and a plurality of A ¹³ O present in the molecule may be the same or different, and n3 is the above. It indicates the average number of moles of alkyleneoxy group added, and is an integer of 1 to 5. }

By providing the above-mentioned structure, the electrolytic cleaning agent of the present invention can exhibit excellent liquid drainage property in electrolytic cleaning of metals.

The electrolytic cleaning agent of the present invention preferably further contains at least one compound selected from the group consisting of the compound represented by the following general formula (2) and the compound represented by the following general formula (3).

In the above formula (2), R ²¹ represents a linear or branched aliphatic hydrocarbon group having 8 to 22 carbon atoms, a monostyrene phenyl group, a distyrene phenyl group, or a tristyrene phenyl group, and A. ²¹ O represents an alkyleneoxy group having 2 or 3 carbon atoms, and a plurality of A ²¹ Os existing in the molecule may be the same or different, and m is the average number of moles of the alkyleneoxy group added. Shown are integers from 3 to 50.

In the above formula (3), R ³¹ represents a linear or branched saturated or unsaturated aliphatic hydrocarbon group having 8 to 24 carbon atoms, and A ³¹ O and A ³² O are independently carbons. ^{A 31} O and A ³² O showing the number 2 or 3 alkyleneoxy groups and present in a plurality in the molecule may be the same or different, and p1 and p2 are the average addition molars of the above alkyleneoxy groups. Indicates a number, p1 and p2 each independently indicate an integer of 1 to 30, and (p1 + p2) is an integer of 3 to 60.

The electrolytic cleaning agent of the present invention preferably further contains a chelating agent.

The present invention also provides a metal cleaning method comprising a step of immersing a dirty metal in a cleaning liquid containing the electrolytic cleaning agent according to the present invention to perform electrolytic cleaning.

According to the metal cleaning method of the present invention, the electrolytic cleaning agent according to the present invention can exhibit excellent liquid drainage in the electrolytic cleaning of metals, so that the efficiency of the cleaning process can be improved. For example, it is possible to reduce the defect rate due to the reattachment of dirt components in post-processing such as plating and painting, and to suppress an increase in energy cost for drying materials and parts.

The metal may be a steel plate. Since steel sheets are the base materials for various metal parts, it is necessary to secure the production amount, and they are continuously produced day and night. The steel sheet manufacturing process includes a rolling process and a cleaning process in which rolling oil is applied to the original plate and thinly stretched by a rolling roll. By applying the metal cleaning method according to the present invention as this cleaning process, the production efficiency is increased. Can be improved. Further, the electrolytic cleaning agent according to the present invention obtains excellent detergency (hereinafter, may be referred to as "low temperature detergency") even when the temperature of the cleaning tank is lowered (about 40 to 80 ° C.). Therefore, the temperature of the cleaning tank in the electrolytic cleaning step during the production process can be lowered, and the amount of electric power required for heating can be suppressed. Further, by continuously manufacturing the steel sheet (continuous electrolytic cleaning), rolling oil containing esters and fatty acids accumulates in the cleaning tank as a stain component. According to the electrolytic cleaning agent according to the present invention. , Even in a state containing such a stain component, the cleaning property can be sufficiently maintained (hereinafter, may be referred to as "cleaning durability"), and the frequency of replacement of the cleaning agent can be reduced.

According to the present invention, it is possible to provide an electrolytic cleaning agent capable of exhibiting excellent liquid drainage in metal cleaning and a metal cleaning method using the electrolytic cleaning agent.

Hereinafter, preferred embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments.

The electrolytic cleaning agent of the present embodiment (hereinafter, also simply referred to as “cleaning agent”) is an alkaline agent and a compound represented by the following general formula (1) (hereinafter, also simply referred to as “compound (1)”). Including.

In the above formula ^{(1), A 11} O, and ^{A 12} O each independently represent an alkylene group having 2 or 3 carbon atoms, ^{A 11} O, and ^{A 12} O in which there are a plurality in the molecule, a same It may be different, and n1 and n2 indicate the average number of moles of the alkyleneoxy group added, which is an integer of 1 to 5, and R ¹¹ is a linear or branched saturation having 4 to 22 carbon atoms. Alternatively, it represents an unsaturated aliphatic hydrocarbon group, R ¹² represents an aralkyl group having 7 to 9 carbon atoms or a monovalent organic group represented by the following general formula (I), and X ⁻ represents a monovalent anion. Shown.
− (A ¹³ O) _n3 −H (I)
{In formula (I), A ¹³ O represents an alkyleneoxy group having 2 or 3 carbon atoms, and a plurality of A ¹³ O present in the molecule may be the same or different, and n3 is the above. It indicates the average number of moles of alkyleneoxy group added, and is an integer of 1 to 5. }

By providing the above-mentioned structure, the cleaning agent of the present embodiment can exhibit excellent liquid drainage property in electrolytic cleaning of metals. In addition, the cleaning agent of the present embodiment can have excellent low-temperature cleaning properties and cleaning durability.

<Compound (1)>
From the viewpoint of liquid drainage, low-temperature cleaning property, and cleaning durability, the compound (1) preferably has n1 to n3 in the general formula (1) of 1-3, and more preferably 1-2. preferable.

The compound (1) may have one type of alkylene oxide added alone or two types of alkylene oxides may be block-added or randomly added as ^{A 11} O in the above general formula (1). The same applies to ^{A 12} O in the general formula (1) ^{and A 13} O in the general formula (I).

From the viewpoint of liquid drainage, low-temperature cleaning property and cleaning durability, the content of ethyleneoxy group in compound (1) is 30 mol% with respect to the total addition molars of alkyleneoxy groups contained in compound (1). The above is preferable, and 100 mol% (that is, all of A ¹¹ O, A ¹² O and A ¹³ O are ethyleneoxy groups) is more preferable.

From the viewpoint of liquid drainage, low-temperature cleaning property and cleaning durability, the compound (1) has a ^{linear or branched saturated or unsaturated R 11} in the above general formula (1) having 8 to 18 carbon atoms. It is preferably an aliphatic hydrocarbon group, and more preferably a linear or branched saturated or unsaturated aliphatic hydrocarbon group having 8 to 12 carbon atoms.

From the viewpoint of liquid drainage, low-temperature cleaning property and cleaning durability, the compound (1) contains a ^{linear or branched alkyl group in which R 11} in the general formula (1) has 4 to 22 carbon atoms, and carbon. It is preferably a linear or branched alkenyl group having a number of 4 to 22, a linear or branched alkyl group having 8 to 18 carbon atoms, and a linear or branched alkyl group having 8 to 18 carbon atoms. It is more preferably an alkenyl group, and further preferably a linear or branched alkyl group having 8 to 12 carbon atoms and a linear or branched alkenyl group having 8 to 12 carbon atoms.

From the viewpoint of liquid drainage, low-temperature cleaning property and cleaning durability, the compound (1) is ^{preferably an aralkyl group in which R 12} in the general formula (1) has 7 to 9 carbon atoms, and is a benzyl group. Is more preferable.

The compound (1) is not particularly limited as long ^{as X −} in the general formula (1) is a monovalent anion. Examples of such monovalent anions include halide ions (eg, chloride ions and bromide ions, etc.); alkylbenzene sulfonate ions (eg, p-toluene sulfonate ions, p-xylene sulfonate ions, etc.) and the like. Sulfate anion such as alkyl sulfonic acid ion having 1 to 18 carbon atoms; Sulfate ester such as alkyl sulfate ion (methyl sulfate ion, ethyl sulfate ester ion, etc.), alkenyl sulfate ion, polyoxyalkylene alkyl ether sulfate ion, etc. Anions and the like can be mentioned. From the viewpoint of detergency, the monovalent anion is preferably a halide ion or an alkylbenzene sulfonic acid ion.

Compound (1) can be blended alone or in combination of two or more.

The content of the compound (1) in the cleaning agent is preferably 0.25 to 15 parts by mass, and more preferably 0.25 to 12 parts by mass with respect to 100 parts by mass of the alkaline agent. When the content of the compound (1) is in the above range, the cleaning agent can be more excellent in liquid drainage, low temperature cleaning property and cleaning durability.

Compound (1) can be obtained by a conventionally known production method, and can be produced, for example, by the following method.

(Compound ^{R 12} is an aralkyl group having 7 to 9 carbon atoms)
Such a compound can be obtained, for example, by the method shown below.

(I) An aliphatic amine (amine having an aralkyl group having 7 to 9 carbon atoms) as a raw material is added with a predetermined alkylene oxide while being heated under high pressure using an alkali catalyst such as potassium hydroxide. A method for quaternizing with a quaternizing agent having an aralkyl group having 7 to 9 carbon atoms or a monovalent organic group represented by the above general formula (I) (for example, halogenated aralkyl such as benzyl chloride). The temperature at which the alkylene oxide is added to the aliphatic amine may be, for example, 100 to 150 ° C.

( ^{A compound in which R 12} is a monovalent organic group represented by the above general formula (I))
Such a compound can be obtained, for example, by the method shown below.

(I) After adding a predetermined alkylene oxide to trialkanolamine as a raw material while heating under high pressure using an alkali catalyst such as potassium hydroxide, a linear or branched chain having 4 to 22 carbon atoms is added. Using a quaternizing agent having a saturated or unsaturated aliphatic hydrocarbon group (for example, a halide having a linear or branched saturated or unsaturated aliphatic hydrocarbon group having 4 to 22 carbon atoms) How to make it 4th grade. The temperature at which the alkylene oxide is added to the trialkanolamine may be, for example, 110 to 180 ° C.

(Ii) An aliphatic amine having a linear or branched saturated or unsaturated aliphatic hydrocarbon group having 4 to 22 carbon atoms and having a predetermined alkylene oxide added is neutralized with an acid, and then under high pressure. A method of adding a predetermined alkylene oxide while heating with. As the acid, an acid capable of producing a monovalent anion such as alkyl sulfuric acid, p-toluenesulfonic acid and hydrochloric acid can be used. The temperature at which the predetermined alkylene oxide is added may be, for example, 100 to 150 ° C.

<Alkaline agent>
The alkaline agent used in the cleaning agent of the present embodiment is not particularly limited as long as it is a water-soluble alkaline agent. Examples of such an alkaline agent include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, alkali metal silicates such as sodium orthosilicate, sodium metasilicate and sodium sesquisilicate, and trisodium phosphate. Examples thereof include alkali metal phosphates, alkali metal carbonates such as disodium carbonate, sodium hydrogencarbonate and dipotassium carbonate, and alkali metal borates such as sodium borate. From the viewpoint of ensuring the removability of oil stains and improving the detergency, the alkaline agent is preferably an alkali metal hydroxide and an alkali metal silicate, and sodium hydroxide, potassium hydroxide, sodium orthosilicate and meta. Sodium silicate is more preferred, and sodium hydroxide and potassium hydroxide are even more preferred.

The alkaline agent can be blended alone or in combination of two or more.

The cleaning agent of the present embodiment includes a compound represented by the following general formula (2) (hereinafter, also simply referred to as “compound (2)”) and a compound represented by the following general formula (3) (hereinafter, simply “compound”. It may further contain at least one compound selected from the group consisting of (also referred to as "(3)"). In this case, the cleaning agent may be more excellent in liquid drainage, low temperature cleaning property and cleaning durability.

In the above formula (2), R ²¹ represents a linear or branched aliphatic hydrocarbon group having 8 to 22 carbon atoms, a monostyrene phenyl group, a distyrene phenyl group, or a tristyrene phenyl group, and A. ²¹ O represents an alkyleneoxy group having 2 or 3 carbon atoms, and a plurality of A ²¹ Os existing in the molecule may be the same or different, and m is the average number of moles of the alkyleneoxy group added. Shown are integers from 3 to 50.

In the above formula (3), R ³¹ represents a linear or branched saturated or unsaturated aliphatic hydrocarbon group having 8 to 24 carbon atoms, and A ³¹ O and A ³² O are independently carbons. ^{A 31} O and A ³² O showing the number 2 or 3 alkyleneoxy groups and present in a plurality in the molecule may be the same or different, and p1 and p2 are the average addition molars of the above alkyleneoxy groups. Indicates a number, p1 and p2 each independently indicate an integer of 1 to 30, and (p1 + p2) is an integer of 3 to 60.

<Compound (2)>
From the viewpoint of liquid drainage, low-temperature cleaning property and cleaning durability, the compound (2) is ^{an aliphatic hydrocarbon in which R 21} in the general formula (2) is linear or branched and has 8 to 16 carbon atoms. It is preferably a group, more preferably a linear or branched aliphatic hydrocarbon group having 8 to 12 carbon atoms, and a linear aliphatic hydrocarbon group having 8 to 12 carbon atoms. Is more preferable. From the same viewpoint, the aliphatic hydrocarbon group is preferably an alkyl group or an alkenyl group.

The compound (2) may have one type of alkylene oxide added alone or two types of alkylene oxides may be block-added or randomly added as ^{A 21} O in the above general formula (2).

From the viewpoint of liquid drainage, low-temperature cleaning property and cleaning durability, the content of the propyleneoxy group of the compound (2) is 10 to 50 with respect to the total number of moles of the alkyleneoxy group added to the compound (2). It is preferably in mol%, more preferably 10 to 40 mol%, still more preferably 15 to 35 mol%.

From the viewpoint of liquid drainage, low-temperature cleaning property and cleaning durability, the compound (2) preferably has m in the above general formula (2) as an integer of 5 to 40, and an integer of 8 to 25. Is more preferable.

Compound (2) can be blended alone or in combination of two or more.

Compound (2) can be obtained by a conventionally known production method, and can be produced, for example, by the following method.
(I) Alcohol catalysts such as potassium hydroxide, sodium hydroxide and sodium methylate are added to a linear or branched aliphatic alcohol or styrene phenol having an aliphatic hydrocarbon group having 8 to 22 carbon atoms as a raw material. A method of reacting by adding a predetermined alkylene oxide while heating under high pressure. The temperature at which the alkylene oxide is added may be, for example, 110 to 180 ° C.

<Compound (3)>
The compound (3) may have one type of alkylene oxide added alone or two types of alkylene oxides may be block-added or randomly added as ^{A 31} O in the above general formula (3). The same applies to ^{A 32} O in the general formula (3).

From the viewpoint of liquid drainage, low-temperature cleaning property and cleaning durability, the content of propyleneoxy group in compound (3) is 10 to 50 with respect to the total number of moles of alkyleneoxy group added in compound (3). It is preferably in mol%, more preferably 10 to 40 mol%, still more preferably 15 to 35 mol%.

From the viewpoint of liquid drainage, low-temperature cleaning property and cleaning durability, the compound (3) is ^{saturated or unsaturated in which R 31} in the above general formula (3) is linear or branched and has 8 to 16 carbon atoms. It is preferably an aliphatic hydrocarbon group, and more preferably a linear or branched saturated or unsaturated aliphatic hydrocarbon group having 8 to 12 carbon atoms.

From the viewpoint of liquid drainage, low-temperature cleaning property and cleaning durability, the compound (3) has ^{an alkyl group in which R 31} in the general formula (3) is linear or branched and has 8 to 16 carbon atoms. It is preferably a linear or branched alkenyl group having 8 to 16 carbon atoms, a linear or branched alkyl group having 8 to 12 carbon atoms, and a linear or branched alkyl group having 8 to 12 carbon atoms. More preferably, it is an alkenyl group of.

From the viewpoint of liquid drainage, low-temperature cleaning property and cleaning durability, the compound (3) preferably has p1 and p2 in the above general formula (3) being integers in which (p1 + p2) is 5 to 40. More preferably, it is an integer of ~ 30.

Compound (3) can be blended alone or in combination of two or more.

Compound (3) can be obtained by a conventionally known production method, and can be produced, for example, by the following method.
(I) An aliphatic amine having a saturated or unsaturated aliphatic hydrocarbon group having 8 to 24 carbon atoms, which is a linear or branched raw material, and an alkali such as potassium hydroxide, sodium hydroxide and sodium methylate. A method of reacting by adding a predetermined alkylene oxide while heating under high pressure using a catalyst. The temperature at which the alkylene oxide is added may be, for example, 110 to 180 ° C.

The total content of the compound (2) and the compound (3) in the cleaning agent is preferably 0.50 to 30 parts by mass, and 0.75 to 10 parts by mass with respect to 100 parts by mass of the alkaline agent. More preferably, it is a part. When the contents of the compound (2) and the compound (3) are in the above-mentioned range, the cleaning agent can be further excellent in liquid drainage property, low temperature cleaning property and cleaning durability.

The cleaning agent of the present embodiment may further contain a chelating agent. In this case, when the chelating agent chelate the metal ions such as iron ions, stains such as metal soap are less likely to occur, and the detergency of the oil can be improved.

<Chelating agent>
Examples of the chelating agent include aldonic acids such as gluconic acid, glucoheptonic acid, glyceric acid, tetronic acid, pentonic acid, hexonic acid and heptonic acid, alkali metal salts thereof, or lower amine salts having 1 to 4 carbon atoms; nitrilotriacetic acid and ethylenediamine. Alkali metal salt or lower amine salt of aminocarboxylic acid such as tetraacetic acid, ethylenediamine diacetic acid, tetraethylenetetramine hexaacetic acid; alkali metal salt or lower amine salt of citric acid, malic acid or the like or oxycarboxylic acid thereof; aminotrimethylenephosphone Phosonic acids such as acids, hydroxyethylidene diphosphonic acid, ethylenediaminetetramethylenephosphonic acid, diethylenetriaminepentamethylenephosphonic acid or alkali metal salts or lower amine salts thereof; polycarboxylic acids and neutralized salts thereof; and other monoethanolamines described above. Examples thereof include alkanolamine salts such as diethanolamine and triethanolamine. From the viewpoint of sustainability of cleaning performance, the chelating agent is preferably a phosphonic acid or an alkali metal salt thereof, a polycarboxylic acid and a neutralized salt thereof, and more preferably a polycarboxylic acid and a neutralized salt thereof.

Examples of the polycarboxylic acid include polycarboxylic acids having a weight average molecular weight of 500 to 150,000, preferably 1,000 to 100,000 polycarboxylic acids from the viewpoint of cleanability and handleability, and 1,000 to 50. 000 polycarboxylic acids are more preferred. As used herein, the weight average molecular weight of a polycarboxylic acid means a value measured by gel permeation chromatography (GPC).

As the polycarboxylic acid, for example, a homopolymer and a common weight synthesized by a conventionally known radical polymerization method using a vinyl-based monomer having a carboxyl group such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, and itaconic acid. Coalescence is mentioned. As the polycarboxylic acid, a commercially available one may be used. In addition to the above-mentioned monomers, a copolymerizable monomer having no carboxyl group may be used in combination with the radical polymerization as long as the present invention is not impaired.

Examples of copolymerizable monomers having no carboxyl group include vinyl-based monomers such as ethylene, vinyl chloride and vinyl acetate, acrylamide, acrylates and methacrylates. As the acrylates and methacrylates, those having an alkyl group having 1 to 3 carbon atoms or an alkenyl group having 2 to 3 carbon atoms are preferable. These alkyl groups or alkenyl groups may have a substituent such as a hydroxyl group. Examples of such acrylates and methacrylates include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, propyl acrylate, propyl methacrylate and the like. The weight ratio of the vinyl-based monomer having a carboxyl group to the copolymerizable monomer having no carboxyl group is preferably 100: 0 to 50:50, preferably 100: 0 to 70, from the viewpoint of cleanability. It is more preferably: 30, and even more preferably 100: 0 to 90:10. The above-mentioned copolymerizable monomers may be used alone or in combination of two or more.

Examples of the neutralizing salt of the polycarboxylic acid include a neutralizing salt obtained by neutralizing the polycarboxylic acid with an alkali metal, ammonium, alkanolamine or the like. Here, examples of the alkali metal include sodium, potassium, lithium and the like. Examples of the alkanolamine include mono, di or trialkanol (1 to 3 carbon atoms) amines. These can be used alone or in combination of two or more.

The chelating agent can be blended alone or in combination of two or more.

The content of the chelating agent in the cleaning agent is preferably 0.050 to 3.5 parts by mass, and more preferably 0.075 to 1.0 parts by mass with respect to 100 parts by mass of the alkaline agent. When the content of the chelating agent is in the above range, the cleaning agent can be more excellent in liquid drainage, low temperature cleaning property and cleaning durability.

<Other ingredients>
Defoamers, preservatives, rust inhibitors, antioxidants, colorants, deodorants, air fresheners, solvents and surfactants other than compounds (1) to (3), as long as the effects of the present invention are not impaired. Etc. can be blended with the cleaning agent of the present embodiment. Each component can be blended alone or in combination of two or more.

The defoaming agent is not particularly limited, and examples thereof include silicone-based, polyglycol-based, higher alcohol-based, and mineral oil-based.

The preservative is not particularly limited, and examples thereof include aromatic carboxylic acids, and specific examples thereof include benzoic acid, p-toluic acid, p-ethylbenzoic acid, p-isopropylbenzoic acid, p-tert-butylbenzoic acid, and the like. Examples thereof include xylyl acid, isophthalic acid, terephthalic acid, salicylic acid, silicic acid, toluic acid, hemimeric acid, trimellitic acid, trimesic acid, hydroxybenzoic acid, dihydroxybenzoic acid, and trihydroxybenzoic acid.

Examples of the rust preventive include aliphatic dicarboxylic acids, alkylphosphonic acids, benzotriazoles, benzothiazoles, (2-benzothiazilthio) acetic acid or 3- (2-benzothiazilthio) propionic acid. Can be done.

Examples of the solvent include water, alcohol, glycol ether, alkylene glycol alkyl ether and the like. Examples of the alcohol include monohydric alcohols having 1 to 4 carbon atoms, polyhydric alcohols such as alkylene glycols having 2 to 6 carbon atoms, glycerin and benzyl alcohol, and examples of glycol ethers are dialkylenes having 2 to 4 carbon atoms. Examples thereof include glycols, trialkylene glycols having 2 to 4 carbon atoms, tetraalkylene glycols having 2 to 4 carbon atoms, and examples of the alkylene glycol alkyl ethers are alkylene glycols having 2 to 6 carbon atoms or dialkylenes having 2 to 4 carbon atoms. Examples thereof include glycols, trialkylene glycols having 2 to 4 carbon atoms, tetraalkylene glycols having 2 to 4 carbon atoms, and compounds in which an alkyl group having 1 to 4 carbon atoms is bonded via an ether bond.

Examples of the surfactant other than the compounds (1) to (3) include nonionic surfactants such as fatty acid alkylene oxide adducts and polyhydric alcohol fatty acid ester alkylene oxide adducts; alkylamino fatty acid salts, alkyl betaines, alkylamine oxides and the like. Examples of amphoteric surfactants.

<Metal cleaning method>
The metal cleaning method of the present embodiment includes a step of immersing a dirty metal in a cleaning liquid containing the cleaning agent of the above embodiment for electrolytic cleaning (hereinafter, also simply referred to as “electrolytic cleaning step”).

The electrolytic cleaning method is not particularly limited, but a cathode electrolytic cleaning method, an anodic electrolytic cleaning method, a PR electrolytic cleaning method, and the like are preferably used.

The metal that can be electrocleaned using a cleaning agent is not particularly limited as long as it is a substance having a metal component, but for example, iron, aluminum, zinc, magnesium, gold, silver, copper, lead and the like. Examples thereof include metals such as titanium and alloys thereof (for example, alloys such as steel plate, brass, stainless steel, and duralmin / titanium); plated metals such as totan.

The temperature of the cleaning agent during electrolytic cleaning is not particularly limited, but may be 20 to 80 ° C, preferably 40 to 80 ° C. The cleaning time varies depending on the shape and size of the object to be cleaned, the cleaning method, and the cleaning conditions, and is not particularly limited and can be set as appropriate.

The pH of the cleaning agent is preferably 7.0 or higher, more preferably 9.0 or higher, and even more preferably 11.0 or higher, from the viewpoint of rust prevention and product stability. If the pH is less than 7.0, it can be adjusted with the above alkaline agent. Even when the above alkaline agent is used as a pH adjuster, the pH adjuster can be blended alone or in combination of two or more. The pH of the cleaning agent can be measured by a known method such as a glass electrode method.

The cleaning agent may be used as it is as a cleaning liquid, or the cleaning agent may be diluted with water before use. The content of the alkaline agent contained in the cleaning liquid is preferably 0.50 to 10% by mass, preferably 0.75 to 5% by mass, based on the total amount of the cleaning liquid, from the viewpoint of cleanability and economy. More preferably, it is even more preferably 1.00 to 3% by mass.

In the metal cleaning method of the present embodiment, the metal may be a steel plate. By applying the metal cleaning method of the present embodiment as a cleaning process in the production of a steel sheet, it is possible to reduce the defect rate due to reattachment of dirt components in post-processing such as plating and painting, and to reduce the energy for drying the steel sheet. It is possible to suppress an increase in cost and improve the manufacturing efficiency of steel sheets. Further, since the electrolytic cleaning agent of the present embodiment is excellent in low-temperature cleaning property, the temperature of the cleaning tank in the electrolytic cleaning process during the production process can be lowered, and the amount of electric energy required for heating can be suppressed. Further, since the electrolytic cleaning agent of the present embodiment is excellent in cleaning durability, it is possible to reduce the frequency of replacement of the cleaning agent and facilitate continuous production of steel sheets.

The method for producing a steel sheet according to the present embodiment includes a rolling step of stretching the base plate of the steel sheet coated with rolling oil with a rolling roll, and a step of immersing the rolled steel sheet in a cleaning liquid containing the cleaning agent of the above embodiment for electrolytic cleaning. And may be provided.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

<Synthesis of cationic surfactant>
(Synthesis Example 1)
1 mol of coconut oil aliphatic amine was charged into a pressure-resistant reaction vessel (autoclave), the autoclave was replaced with nitrogen, and then 2 mol of ethylene oxide was blown at 120 to 130 ° C. Then, aging was carried out for 4 hours to obtain a 2 mol adduct (intermediate) of ethylene oxide of laurylamine. An intermediate and the same amount of distilled water by mass ratio were added to a four-necked flask equipped with a recirculation condenser, and 1.1 mol of benzyl chloride was added dropwise at 85 to 95 ° C. After completion of the dropping, the composition (A1) was obtained by advancing the quaternization reaction by aging for 4 hours. The composition (A1) was ^{analyzed by 1} H-NMR and ¹³ C-NMR [trade name: JMN-ECZ500R, manufactured by Nippon Denshi Co., Ltd.], and in the above general formula (1), R ¹¹ was coconut oil. Aliphatic hydrocarbon groups derived from aliphatic amines having 8 to 18 carbon atoms, R ¹² is a benzyl group, A ¹¹ O and A ¹² O are ethylene oxy groups (“EO”), n1 and n2 are 1, and X, respectively. ^{It was confirmed that 60% by mass of a compound in which −} is a chloride ion (hereinafter, also referred to as “benzyl quaternized product of coconut oil aliphatic amine EO (2) adduct”).

(Synthesis Example 2)
1 mol of coconut oil aliphatic amine was charged into a pressure-resistant reaction vessel (autoclave), the autoclave was replaced with nitrogen, and then 2 mol of ethylene oxide was blown at 120 to 130 ° C. Then, aging was carried out for 4 hours to obtain a 2 mol adduct (intermediate) of ethylene oxide of laurylamine. Distilled water in the same mass ratio as this intermediate was added to the intermediate, and 0.97 molar equivalents of p-toluenesulfonic acid was further mixed and neutralized. After the autoclave was replaced with nitrogen, 1.1 mol of ethylene oxide was blown into the autoclave again at 85 to 95 ° C. The quaternization reaction was allowed to proceed by aging for 4 hours to obtain the composition (A2). The composition (A2) was ^{analyzed by 1} H-NMR and ¹³ C-NMR [trade name: JMN-ECZ500R, manufactured by Nippon Denshi Co., Ltd.], and in the above general formula (1), R ¹¹ was coconut oil. Aliphatic hydrocarbon groups derived from aliphatic amines having 8 to 18 carbon atoms, R ¹² is a monovalent organic group represented by the above general formula (I), and A ^{11 O to A 13} O are ethylene oxy groups, respectively. ( "EO"), n1 to n3 each 1, X ^- compound is p- toluenesulfonic acid ion (hereinafter, also referred to as "ethylene oxide quaternization products of coconut fatty amine EO (2) adduct") Was confirmed to contain 64% by mass.

［式（Ａ）中、Ｒ^４１はヤシ油脂肪族アミン由来の炭素数が８〜１８である脂肪族炭化水素基を示す。］ (Comparative Synthesis Example 1)
1 mol of coconut oil aliphatic dimethylamine and double the amount of distilled water by mass ratio were placed in a four-necked flask equipped with a recirculation condenser, and 1.1 mol of benzyl chloride was added dropwise at 85 to 95 ° C. After completion of the dropping, aging was carried out for 4 hours to proceed with the quaternization reaction, and the composition (A3) was obtained. The composition (A3) is ^{analyzed by 1} H-NMR and ¹³ C-NMR [trade name: JMN-ECZ500R, manufactured by JEOL Ltd.], and is a compound represented by the following formula (A) (hereinafter referred to as “A”). It was confirmed that 62.5% by mass of (also referred to as "benzyl quaternary chloride of coconut oil aliphatic dimethylamine") was contained.

[In the formula (A), R ⁴¹ represents an aliphatic hydrocarbon group derived from a coconut oil aliphatic amine and having 8 to 18 carbon atoms. ]

<Synthesis of nonionic surfactant>
(Synthesis Example 3)
After charging 1 mol of lauryl alcohol and 0.4% by mass of potassium hydroxide in a pressure-resistant reaction vessel (autoclave) and replacing the autoclave with nitrogen, 8 mol of ethylene oxide is blown at 120 to 130 ° C. to reduce the internal pressure and become constant. Aged until. Then, a mixture of 3 mol of ethylene oxide and 2 mol of propylene oxide was blown into the autoclave, and the autoclave was aged until the internal pressure decreased and became constant. Then, 8 mol of ethylene oxide was blown into the autoclave, and the autoclave was aged until the internal pressure decreased and became constant. Then, the temperature in the autoclave was lowered to room temperature to obtain the composition (C1). The composition (C1) was ^{analyzed by 1} H-NMR and ¹³ C-NMR [trade name: JMN-ECZ500R, manufactured by JEOL Ltd.], and in the above general formula (2), R ²¹ was a lauryl group. , (A ²¹ O) _m is (EO) ₈ -[(EO) ₃ / (PO) ₂ ]-(EO) ₈ compound (hereinafter, "EO (8)-[EO (3) / of lauryl alcohol") It was confirmed that it contained 99.2% by mass of (PO (2)]-EO (8) adduct).
EO is an ethyleneoxy group, PO represents a propyleneoxy _{group, [(EO) 3 / (} PO) 2] , relative to 1 mole of ^{R 21,} average of 3 moles of ethylene oxide and average 2 moles of propylene oxide and Indicates that is added randomly.

(Synthesis Example 4)
After charging 1 mol of lauryl alcohol and 0.4% by mass of potassium hydroxide in a pressure-resistant reaction vessel (autoclave) and substituting nitrogen in the autoclave, 10 mol of ethylene oxide is blown at 120 to 130 ° C. to reduce the internal pressure and become constant. After aging to, the temperature in the autoclave was lowered to room temperature to obtain the composition (C2). The composition (C2) was ^{analyzed by 1} H-NMR and ¹³ C-NMR [trade name: JMN-ECZ500R, manufactured by JEOL Ltd.], and in the above general formula (2), R ²¹ was a lauryl group. , A ²¹ O was confirmed to contain 99.3% by mass of a compound having an ethyleneoxy group and m of 10 (hereinafter, also referred to as “EO (10) adduct of lauryl alcohol”).

(Synthesis Example 5)
After charging 1 mol of tristyrene phenol and 0.4% by mass of potassium hydroxide in a pressure-resistant reaction vessel (autoclave) and replacing the autoclave with nitrogen, 10 mol of ethylene oxide was blown at 120 to 130 ° C. to reduce the internal pressure and keep it constant. It was aged until it became. Then, the temperature in the autoclave was lowered to room temperature to obtain the composition (C3). The composition (C3) was ^{analyzed by 1} H-NMR and ¹³ C-NMR [trade name: JMN-ECZ500R, manufactured by JEOL Ltd.], and in the above general formula (2), R ²¹ was tristyrene. It was confirmed that the compound containing a phenyl compound, A ²¹ O having an ethyleneoxy group, and m of 10 (hereinafter, also referred to as “tristyrene phenol EO (10) adduct”) was contained in an amount of 99.6% by mass.

(Synthesis Example 6)
1 mol of coconut oil aliphatic amine and 0.4% by mass of potassium hydroxide were charged in a pressure-resistant reaction vessel (autoclave), and the autoclave was replaced with nitrogen. Next, the inside of the autoclave was dehydrated under reduced pressure at 110 to 120 ° C., and 10 mol of ethylene oxide was blown at 120 to 130 ° C. Then, aging was carried out until the internal pressure decreased and became constant, and then the temperature in the autoclave was lowered to room temperature to obtain the composition (C4). The composition (C4) was ^{analyzed by 1} H-NMR and ¹³ C-NMR [trade name: JMN-ECZ500R, manufactured by JEOL Ltd.], and in the above general formula (3), R ³¹ was coconut oil. Aliphatic hydrocarbon groups derived from aliphatic amines having 8 to 18 carbon atoms ^{, compounds having A 31} O and A ³² O having ethyleneoxy groups and p1 + p2 having 10 (hereinafter, “palm oil aliphatic amine EO (10)) It was confirmed that 99.3% by mass of (also referred to as "additive") was contained.

<Adjustment of cleaning agent>
[Examples 1 to 11 and Comparative Examples 1 to 3]
The materials shown in Tables 1 to 3 were blended so as to have the concentrations (% by mass) shown in the same table, and the cleaning agent was adjusted. In Tables 1 to 3, the concentrations of the cationic surfactant and the nonionic surfactant are determined in the compositions (A1) to (A3), the compositions (C1) to (C4) and the softanol 120 with respect to the total amount of the cleaning agent. The ratio of the active ingredient contained is shown. Details of the sophthalol 120 used as the compound (2) and the polymaleic acid used as the chelating agent are as follows.
-Sophthalol 120 (manufactured by Nippon Shokubai Co., Ltd., trade name, in the above general formula (2) ^{, 99.9 mass of a compound in which R 21} is a branched dodecyl group, A ²¹ O is EO, and m is 12. Composition containing%)
Polymaleic acid (weight average molecular weight: 9300)

<Evaluation method>
The cleaning agents of Examples and Comparative Examples were evaluated for initial cleaning property, durability of cleaning performance, and liquid drainage by the following evaluation methods.

{Initial detergency}
Two commercially available cold-rolled steel sheets (SPCC-SB) cut into 50 mm × 50 mm × 1 mm were used as test pieces. The surface of the test piece was washed with n-hexane, and 0.03 g of rolling oil (palm oil) was applied as a contaminant to prepare a contaminated sample. Contaminated samples were immersed in the adjusted cleaning agent so that the distance between them was 10 mm. Next, one test piece was connected to the positive electrode, the other was connected to the negative electrode and energized for 2 seconds, and then the positive and negative electrodes were reversed and connected and energized for 2 seconds to energize for a total of 4 seconds for electrolytic cleaning. After energization, the test piece was thoroughly rinsed with running water and dried at 80 ° C. for 30 minutes. The weight of the dried test piece was measured, and the cleaning rate was calculated by the following formula. The cleaning rate was evaluated according to the following evaluation criteria. The results are shown in Tables 1-3.

(Electrolytic cleaning conditions)
Power supply: DC power supply Current density: 9A / dm ²
Electrolysis time: 2 seconds Cleaning liquid temperature: 40 ° C
(Washing rate)
Cleaning rate (% by mass) = [{Weight of contaminated sample before cleaning (g)}-{Weight of contaminated sample after cleaning (g)}] / [{Weight of contaminated sample before cleaning (g)}-{ Test piece weight (g)}] x 100
(Evaluation criteria)
5: Cleaning rate is 70% or more (very good)
4: The cleaning rate is 60% or more and less than 70% (good).
3: The cleaning rate is 50% or more and less than 60% (normal)
2: The cleaning rate is 40% or more and less than 50% (slightly defective).
1: Cleaning rate is less than 40% (poor)

{Durability of cleaning performance}
The sustainability of the cleaning performance was evaluated in the same manner as the evaluation of the initial cleaning property, except that a cleaning solution containing 480 ppm of sodium palm oil fatty acid was used as a stain component (this is regarded as an aging solution). The results are shown in Tables 1-3.

{Drainage (electrolytic cleaning)}
The test piece was electrolyzed in the same manner as in the initial washability evaluation, except that the cleaning solution used in the evaluation of the sustainability of the cleaning performance was used and no contaminants were applied to the test piece. The weight of the test piece before and after electrolytic cleaning was measured, and the amount of liquid remaining on the test piece was calculated by the following formula. The residual amount was evaluated on a 5-point scale according to the following evaluation criteria. The smaller the residual amount, the better the liquid drainage property. The results are shown in Tables 1-3.
(Amount of liquid remaining)
Residual amount (g / m ² ) = [{Test piece weight after cleaning (g)}-{Test piece weight before cleaning (g)}] / {Surface area of test piece (m ² )}]
(Evaluation criteria)
5: Residual amount is ^{less than 10 g / m 2} (very good)
4: remaining amount is less than 10 g / ^{m 2} or more ~11g / ^{m 2} (which is good)
3: remaining amount is less than 11g / ^{m 2} or more to 12 g / ^{m 2} (average)
2: remaining amount is less than 12 g / ^{m 2} or more ~13g / ^{m 2} (which is somewhat bad)
1: Residual amount is 13 g / m ² or more (defective)

{Drainage (immersion only)}
The test piece, which was not coated with a contaminant, was immersed in the cleaning solution used for evaluating the sustainability of the cleaning performance. The weight of the test piece before and after immersion was measured, and the amount of liquid remaining on the test piece was calculated by the following formula. The residual amount was evaluated based on the same criteria as the evaluation of liquid drainage after electrolytic cleaning. The results are shown in Tables 1-3.
(Amount of liquid remaining)
Residual amount (g / m ² ) = [{Test piece weight after immersion (g)}-{Test piece weight before immersion (g)}] / {Surface area of test piece (m ² )}]

As shown in Tables 1 to 3, it was confirmed that the cleaning agents of Examples 1 to 11 were excellent in liquid drainage, initial cleaning property, and sustainability of cleaning performance. Further, comparing Examples 1 and 2 with Comparative Example 1, although the liquid drainage property after the electrolytic cleaning was the same result, the liquid drainage property after the electrolytic cleaning was found in Example 1. It was confirmed that the cleaning agents of and 2 were excellent.

Claims (5)

An electrolytic cleaning agent containing an alkaline agent and a compound represented by the following general formula (1).

Wherein ^{(1), A 11} O, and ^{A 12} O each independently represent an alkylene group having 2 or 3 carbon atoms, ^{A 11} O, and ^{A 12} O in which there are a plurality in the molecule, a same It may be different, and n1 and n2 indicate the average number of moles of the alkyleneoxy group added, which is an integer of 1 to 5, and R ¹¹ is a linear or branched saturation having 4 to 22 carbon atoms. Alternatively, it represents an unsaturated aliphatic hydrocarbon group, R ¹² represents an aralkyl group having 7 to 9 carbon atoms or a monovalent organic group represented by the following general formula (I), and X ⁻ represents a monovalent anion. Shown.
− (A ¹³ O) _n3 −H (I)
{In formula (I), A ¹³ O represents an alkyleneoxy group having 2 or 3 carbon atoms, and a plurality of A ¹³ O present in the molecule may be the same or different, and n3 is the above. It indicates the average number of moles of alkyleneoxy group added, and is an integer of 1 to 5. }]] The electrolytic cleaning agent according to claim 1, further comprising at least one compound selected from the group consisting of the compound represented by the following general formula (2) and the compound represented by the following general formula (3).

[In formula (2), R ²¹ represents a linear or branched aliphatic hydrocarbon group having 8 to 22 carbon atoms, a monostyrene phenyl group, a distyrene phenyl group, or a tristyrene phenyl group, and A. ²¹ O represents an alkyleneoxy group having 2 or 3 carbon atoms, and a plurality of A ²¹ Os existing in the molecule may be the same or different, and m is the average number of moles of the alkyleneoxy group added. Shown are integers from 3 to 50. ]

[In formula (3), R ³¹ represents a linear or branched saturated or unsaturated aliphatic hydrocarbon group having 8 to 24 carbon atoms, and A ³¹ O and A ³² O are independently carbons. ^{A 31} O and A ³² O showing the number 2 or 3 alkyleneoxy groups and present in a plurality in the molecule may be the same or different, and p1 and p2 are the average addition molars of the alkyleneoxy groups. Indicates a number, p1 and p2 each independently indicate an integer of 1 to 30, and (p1 + p2) is an integer of 3 to 60. ] The electrolytic cleaning agent according to claim 1 or 2, further comprising a chelating agent. A metal cleaning method comprising a step of immersing a dirty metal in a cleaning liquid containing the electrolytic cleaning agent according to any one of claims 1 to 3 to perform electrolytic cleaning. The method for cleaning a metal according to claim 4, wherein the metal is a steel plate.