WO2018123588A1

WO2018123588A1 - Cleaning agent composition for steel sheet

Info

Publication number: WO2018123588A1
Application number: PCT/JP2017/044705
Authority: WO
Inventors: 友太照屋
Original assignee: 花王株式会社
Priority date: 2016-12-26
Filing date: 2017-12-13
Publication date: 2018-07-05
Also published as: JP2018104752A; JP6850603B2; CN110114511A

Abstract

The cleaning agent composition for a steel sheet according to the present invention contains 0.1-6.0 mass% of an alkali agent (component A), 0.01-2.0 mass% of a chelating agent (component B), 0.01-2.0 mass% of a surfactant (component C), 0.02-5.0 mass% of a compound (component D) represented by general formula (I), and water (component E) (in general formula (I), R₁ represents a hydrogen atom or an alkyl group having 2-6 carbon atoms, R₂ represents a hydrogen atom, a hydroxyethyl group, a hydroxypropyl group, an aminoethyl group, or an alkyl group having 1-6 carbon atoms, and R₃ represents a hydroxyethyl group or a hydroxypropyl group). The present invention can prevent oxidation on the surface of a steel sheet while maintaining good cleanability at a low temperature.

Description

Steel plate cleaning composition

The present invention relates to a steel plate cleaning composition, a steel plate cleaning method using the cleaning composition, and a steel plate manufacturing method including the cleaning method in a manufacturing process.

Steel plate cleaning is necessary as a pretreatment for surface treatment such as plating and coating of the steel plate surface, and is a very important factor that determines the quality of products. As dirt adhering to the steel plate surface, oil dirt such as rolling oil and rust preventive oil adhering during cold rolling can be mentioned. In recent cold rolling of steel sheets, rolling oil suitable for improving mill cleanliness and productivity has come to be used, and excellent detergency for the rolling oil is required.

Furthermore, the increase in environmental awareness calls for a reduction in carbon dioxide emissions, which is no exception in steel production. Therefore, in order to reduce energy costs that lead to carbon dioxide emissions, we have attempted to develop a cleaning agent that exhibits excellent cleaning performance even at lower temperatures than the conventional 70-90 ° C cleaning temperature in steel sheet cleaning. It has been.

On the other hand, steel plates that can observe the appearance of steel plates, especially automobiles, home appliances, food and beverage cans, etc. have high surface quality, not only dirt removal, but also oxidation of the steel plate surface that affects surface treatment such as plating. State control has also become important.

In this background, various steel plate cleaning agents have been developed. For example, Japanese Patent Application Laid-Open No. 11-222687 describes an alkaline detergent composition for steel sheets that includes an alkaline agent and a specific polyoxyalkylene alkyl ether and has excellent detergency and is capable of high-speed washing of steel sheets at a low temperature. .

JP 2014-132112 A discloses an alkali agent, one or more organic acids or salts selected from lactic acid, oxalic acid, citric acid and salts thereof, a specific nonionic surfactant, gluconic acid, A steel sheet cleaning agent containing at least one chelating agent selected from ethylenediaminetetraacetic acid and salts thereof and water and having good detergency against oil stains even at low temperatures is described.

The present invention comprises an alkali agent (component A) 0.1 to 6.0 mass%, a chelating agent (component B) 0.01 to 2.0 mass%, and a surfactant (component C) 0.01 to 2.0 mass%. A cleaning composition for steel sheet, which comprises, by mass, 0.02 to 5.0 mass% of a compound (component D) represented by the following general formula (I) and water (component E).

(In General Formula (I), R ₁ is a hydrogen atom or an alkyl group having 2 to 6 carbon atoms, and R ₂ is a hydrogen atom, a hydroxyethyl group, a hydroxypropyl group, an aminoethyl group, or 1 or more carbon atoms. 6 or less alkyl groups, and R ₃ is a hydroxyethyl group or a hydroxypropyl group.)

The present invention is a steel plate cleaning method including a cleaning step of cleaning a steel plate using the steel sheet cleaning composition.

The present invention is a method for producing a steel sheet, comprising a cleaning step of cleaning the steel sheet using the steel sheet cleaning composition.

Detailed Description of the Invention

Although the cleaning compositions described in JP-A-11-222687 and JP-A-2014-132112 have good cleanability at low temperature, the temperature of the steel sheet is higher than that at high temperature cleaning because it is cleaned at low temperature. There is a problem that the amount of heat required for evaporation of water is insufficient in drying after rinsing. To solve this problem, it is conceivable to increase the temperature of hot air during drying. However, increasing the temperature of hot air during drying increases the energy costs that lead to carbon dioxide emissions, so from the perspective of reducing carbon dioxide emissions. Is not preferred. Also, it is conceivable to slow down the line speed and dry at low temperature for a long time, but if the line speed is slowed down, the time that the steel plate is in contact with the cleaning liquid in the cleaning process, the rinsing process, and the drying process becomes longer. As a result of this oxidation, a new problem arises that surface treatment defects such as plating and appearance defects due to rusting occur.

The present invention provides a steel sheet cleaning composition capable of suppressing surface treatment defects such as plating and appearance defects due to rusting while maintaining good cleanability at low temperatures, and the steel sheet. A steel plate cleaning method using the cleaning composition for a steel sheet and a steel plate manufacturing method including the cleaning method in a manufacturing process are provided.

According to the present invention, while maintaining good cleanability at a low temperature, a steel plate cleaning composition that can suppress surface treatment defects such as plating and appearance defects due to rusting even when the line speed is slow, and A steel plate cleaning method using the steel sheet cleaning composition, and a steel plate manufacturing method including the cleaning method in a manufacturing process can be provided.

Hereinafter, an embodiment of the present invention will be described.

<Cleaning composition for steel plate>
The steel sheet cleaning composition of the present embodiment (hereinafter also simply referred to as “cleaning composition”) comprises an alkali agent (component A) of 0.1 to 6.0 mass% and a chelating agent (component B) of 0.01. 2.0% by mass, surfactant (component C) 0.01-2.0% by mass, compound (component D) 0.02-5.0% by mass and water (component) E).

According to the steel sheet cleaning composition of this embodiment, while maintaining good cleanability at low temperatures, it is possible to suppress poor surface treatments such as plating and poor appearance due to rusting even if the line speed is slowed down. . The manifestation mechanism of the effect of this embodiment is not certain, but is considered as follows.

By the action of alkali agent, chelating agent, surfactant and water, organic stains such as rolling oil and rust preventive oil and inorganic stains such as iron powder are removed from the steel sheet surface at low temperature, or it is easy to remove during rinsing. Further, the compound represented by the general formula (I) is formed on the steel plate surface during or after washing to form a protective film that prevents oxidation, thereby thickening the steel plate oxide film in the washing step, the rinsing step, and the drying step. It is presumed that the occurrence of rust and the occurrence of rust can be suppressed. Moreover, it is estimated that this effect can be efficiently exhibited when each component exists in a specific ratio.

[Alkaline agent (component A)]
As the component A, any water-soluble alkaline agent can be used in order to ensure detergency. Among them, an inorganic alkaline agent is preferable. Specific examples of inorganic alkali agents 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. Alkali metal phosphates, alkali metal carbonates such as disodium carbonate, sodium hydrogen carbonate and dipotassium carbonate, and alkali metal borates such as sodium borate can be used. Two or more water-soluble alkaline agents may be combined. From the viewpoint of ensuring the removal of organic stains and improving the cleanability, alkali metal hydroxides and alkali metal silicates are preferred, sodium hydroxide, potassium hydroxide, sodium orthosilicate and sodium metasilicate are more preferred, water More preferred are sodium oxide and potassium hydroxide. As the component A, at least one kind may be used, and two or more kinds may be used in combination. In addition, although the said component D has what shows alkalinity, the said component A is an alkali agent other than the said component D. FIG.

The content of Component A is 0.1% by mass or more, preferably 0.2% by mass or more, more preferably 0.5% by mass or more, and further preferably 1.0% by mass or more from the viewpoint of detergency. Preferably, from the same viewpoint, it is 6.0% by mass or less, preferably 5.0% by mass or less, more preferably 4.0% by mass or less, further preferably 3.5% by mass or less, and 3.0% by mass. The following is even more preferable.

[Chelating agent (component B)]
As the component B, any water-soluble chelating agent can be used to ensure detergency, but the following specific examples are preferred. Specific examples of the component B include aldonic acids such as gluconic acid, glucoheptonic acid, glyceric acid, tetronic acid, pentonic acid, hexonic acid, heptonic acid, or alkali metal salts thereof or lower amine salts having 1 to 4 carbon atoms; Aminocarboxylic acids such as triacetic acid, ethylenediaminetetraacetic acid, ethylenediaminediacetic acid, tetraethylenetetraminehexaacetic acid, or alkali metal salts or lower amine salts thereof; oxycarboxylic acids such as citric acid, malic acid, or alkali metal salts or lower amine salts thereof Phosphonic acids such as aminotrimethylenephosphonic acid, hydroxyethylidenediphosphonic acid, ethylenediaminetetramethylenephosphonic acid, diethylenetriaminepentamethylenephosphonic acid, or alkali metal salts or lower amine salts thereof; Can be used Min, diethanolamine, alkanolamine salts such as triethanolamine. Among these, aldonic acid or a salt thereof is preferable, and an alkali metal salt or a lower amine salt is preferable from the viewpoint of detergency of organic soil. Among these, from the same viewpoint, gluconic acid, alkali metal salts of glucoheptonic acid or lower amine salts are preferable, and gluconate is more preferable. The alkali metal salt is preferably a sodium salt from the viewpoint of improving detergency. The said component B should just use at least 1 sort (s), and can use it in combination of 2 or more type. For example, a combination of an alkali metal salt of gluconic acid and an alkali metal salt of ethylenediaminetetraacetic acid can be used.

The content of Component B is 0.01% by mass or more, preferably 0.02% by mass or more, more preferably 0.05% by mass or more, and further preferably 0.1% by mass or more from the viewpoint of detergency. From the viewpoint of reducing the wastewater treatment load, it is preferably 2.0% by mass or less, preferably 1.5% by mass or less, more preferably 1.0% by mass or less, still more preferably 0.5% by mass or less, and 3 mass% or less is still more preferable. In addition, the content of the component B is a value converted in an acid form in consideration of various salt forms.

[Surfactant (component C)]
As the component C, any surfactant can be used, but nonionic surfactants are preferred from the viewpoints of detergency against organic soils and foam suppression, and non-ionic surfactants represented by the following general formula (II) Ionic surfactants are more preferred. As the component C, at least one kind may be used, and two or more kinds may be used in combination.

R ₄ —O — {(EO) n / (PO) m} —H (II)
(In the general formula (II), R ₄ is a hydrocarbon group having 8 to 18 carbon atoms, EO is an ethyleneoxy group, PO is a propyleneoxy group, n is the average added mole number of EO, and m is the average of PO. Number of moles added, n is 2 or more and 20 or less, m is a number satisfying 0 or more and 20 or less, and the addition form of PO and EO in {} may be either random array or block array.)

In the nonionic surfactant represented by the general formula (II), R ₄ is a hydrocarbon group having 8 to 18 carbon atoms, and an alkyl group, an alkenyl group or an alkylphenyl group from the viewpoint of detergency of organic stains. Are preferable, an alkyl group or an alkenyl group is more preferable, and an alkyl group is more preferable. The number of carbon atoms of R ₄ is preferably 10 or more, more preferably 12 or more from the viewpoint of organic stain detergency, and from the same viewpoint, 16 or less is preferable, and 14 or less is more preferable.

In the nonionic surfactant represented by the general formula (II), EO is an ethyleneoxy group and PO is a propyleneoxy group. Ethyleneoxy groups and propyleneoxy groups have a distribution depending on the number of added moles, but from the viewpoint of detergency of organic stains, the average number of moles of addition of ethyleneoxy groups is from 2 to 20, and the average addition of propyleneoxy groups The number of moles m is 0 or more and 20 or less. The average added mole number n of the ethyleneoxy group is preferably 5 or more, more preferably 8 or more, still more preferably 12 or more, and preferably 18 or less, more preferably 16 or less, from the viewpoint of organic stain detergency. The average added mole number m of the propyleneoxy group is preferably 1 or more, preferably 10 or less, more preferably 5 or less, and even more preferably 3 or less, from the viewpoints of detergency and foam suppression. From the viewpoint of detergency, it is preferable that the average addition mole number n of ethyleneoxy groups is larger than the average addition mole number m of propyleneoxy groups.

Of the nonionic surfactants represented by the general formula (II), nonionic surfactants represented by the following general formula (III) are more preferable from the viewpoints of detergency and foam suppression.

R ₅ —O— (EO) p (PO) q (EO) r—H (III)
(In general formula (III), R ₅ is a hydrocarbon group having 8 to 18 carbon atoms, EO is an ethyleneoxy group, PO is a propyleneoxy group, and p, q, and r are an ethyleneoxy group and a propyleneoxy group, respectively. The average added mole number of ethyleneoxy groups, p is 1 or more and 15 or less, q is 0 or more and 20 or less, r is a number satisfying 1 or more and 15 or less, and q ≦ p + r ≦ 20.

In the nonionic surfactant represented by the general formula (III), R ₅ is a hydrocarbon group having 8 to 18 carbon atoms, and an alkyl group, an alkenyl group or an alkylphenyl group from the viewpoint of detergency of organic stains. Are preferable, an alkyl group or an alkenyl group is more preferable, and an alkyl group is more preferable. The carbon number of R ₅ is preferably 10 or more, more preferably 12 or more from the viewpoint of detergency of organic stains, and preferably 16 or less, more preferably 14 or less from the same viewpoint.

In the nonionic surfactant represented by the general formula (III), EO is an ethyleneoxy group and PO is a propyleneoxy group. The average addition mole numbers p and r of the ethyleneoxy group are each 1 or more and 15 or less, and are each 1 or more, preferably 2 or more, more preferably 4 or more, from the viewpoint of the detergency of organic stains, 5 or more Is more preferably 15 or less, preferably 12 or less, and more preferably 10 or less. The average added mole number q of the propyleneoxy group is 0 or more and 20 or less, and preferably 1 or more, preferably 10 or less, more preferably 5 or less, and 3 or less from the viewpoint of detergency and foam suppression. Further preferred. Further, from the viewpoint of detergency, p + r is not less than q and not more than 20, and is preferably larger than q.

The content of component C is 0.01% by mass or more, preferably 0.02% by mass or more, more preferably 0.03% by mass or more, and further 0.05% by mass or more from the viewpoint of detergency. Preferably, it is 2.0% by mass or less, preferably 1.0% by mass or less, more preferably 0.5% by mass or less, from the viewpoint of reducing the wastewater treatment load and suppressing foam during use and wastewater treatment. .3% by mass or less is more preferable, and 0.2% by mass or less is more preferable.

<Compound represented by formula (I) (component D)>
Specific examples of the component D include diethanolamine, diisopropanolamine, N-methylmonoethanolamine, N-ethylmonoethanolamine, N-isopropylmonoethanolamine, Nn-butylmonoethanolamine, Nt-butyl. Monoethanolamine, Nn-pentylmonoethanolamine, Nn-hexylmonoethanolamine, N-methylmonoisopropanolamine, N-ethylmonoisopropanolamine, Nt-butylmonoisopropanolamine, N, N-diethyl Isopropanolamine, Nn-butyldiisopropanolamine, Nt-butyldiisopropanolamine, N, N-diethylethanolamine, N, N-di-n-butylethanolamine, N, N-di-n-butyl Isopro Nolamine, N-ethyldiethanolamine, N-isopropyldiethanolamine, Nn-butyldiethanolamine, Nt-butyldiethanolamine, N- (β-aminoethyl) monoethanolamine, N- (β-aminoethyl) monoisopropanolamine, etc. Can be used. N-methylmonoethanolamine, N-ethylmonoethanolamine, Nn-butylmonoethanolamine, Nt-butylmonoethanolamine, N, N-diethylethanolamine from the viewpoint of cleaning properties and suppression of oxidation of steel sheet N, N-di-n-butylethanolamine, Nn-butyldiethanolamine, Nt-butyldiethanolamine are preferred, Nn-butylmonoethanolamine, N, N-diethylethanolamine, N, N— Di-n-butylethanolamine is more preferred, Nn-butylmonoethanolamine, N, N-di-n-butylethanolamine is more preferred, and N, N-di-n-butylethanolamine is still more preferred. . As the component D, at least one kind may be used, and two or more kinds may be used in combination.

Content of the said component D is 0.02 mass% or more from a viewpoint of washability and the oxidation suppression of a steel plate, 0.03 mass% or more is preferable, 0.04 mass% or more is more preferable, 0.05 4. More preferably at least 10% by mass, more preferably at least 0.10% by mass, even more preferably at least 0.15% by mass, and even more preferably at least 0.18% by mass. 0 mass% or less, preferably 2.0 mass% or less, more preferably 1.0 mass% or less, further preferably 0.5 mass% or less, and further preferably 0.2 mass% or less.

In one embodiment of the present invention, the component A is an inorganic alkaline agent, and the component B is at least one selected from aldonic acid, aminocarboxylic acid, oxycarboxylic acid, phosphonic acid, or alkali metal salts thereof, The component C is a nonionic surfactant, and the component D is preferably at least one selected from the compounds represented by the general formula (I).

The component A is at least one selected from sodium hydroxide, potassium hydroxide, sodium orthosilicate and sodium metasilicate, and the component B is at least selected from aldonic acid, aminocarboxylic acid or alkali metal salts thereof. More preferably, the component C is a nonionic surfactant represented by the general formula (II), and the component D is at least one selected from the compounds represented by the general formula (I). Preferably, the component A is sodium hydroxide, the component B is an alkali metal salt of aldonic acid and aminocarboxylic acid, the component C is a nonionic surfactant represented by the general formula (III), More preferably, the component D is at least one selected from the compounds represented by the general formula (I).

[Water (component E)]
As the component E, industrial water, tap water, deionized water, and the like can be used. Industrial water is preferable from the viewpoint of supplyability and cost, and ion-exchanged water is preferable from the viewpoint of detergency.

The content of the component E is preferably 85.0% by mass or more, and preferably 99.86% by mass or less. When the steel sheet cleaning composition of the present embodiment contains no components other than the components A to D, the water content in the steel plate cleaning composition is the balance of the components A to D.

[Other ingredients]
The cleaning composition of this embodiment may contain components other than the components A to E generally used as a cleaning agent in a range that does not affect the performance. Examples of components other than the components A to E include solubilizers, dispersants, thickeners and other thickeners, antifoaming agents, corrosion inhibitors, rust inhibitors, and colorants. The cleaning composition of the present embodiment can be prepared by diluting with a medium such as water at the time of use by dividing the concentrate or each component individually or in two or more kits. From the viewpoint of transportation cost, storage cost, and concentration control, it is preferably a concentrated liquid or concentrated powder. From the viewpoint of workability, such as a solubilized transparent one-component type or a slurry type in which some components are dispersed, It is more preferable that The concentrated solution is preferably concentrated 5 to 100 times, and more preferably 10 to 30 times from the viewpoint of storage stability and economy.

The content of components other than the components A to E is preferably 5.0% by mass or less, more preferably 2.0% by mass or less, and further preferably 1.0% by mass or less, within a range not affecting the performance. More preferably, it is 0.5 mass% or less.

<Manufacturing method of steel plate>
The steel sheet cleaning agent of the present embodiment includes, for example, a cold rolling process including a rolling process for cold rolling a steel sheet in the presence of rolling oil and a cleaning process for cleaning the rolling oil adhering to the rolled steel sheet with the cleaning agent. In the manufacturing process of a steel plate, it can be used as an alkali cleaning agent in the cleaning step. That is, the manufacturing method of the steel plate of this embodiment can employ | adopt the method similar to the past except including the washing | cleaning process of wash | cleaning a steel plate using the said cleaning composition for steel plates. The step of cold rolling is a processing step of cold rolling a steel sheet in the presence of rolling oil at an iron mill or the like.

[Washing process]
The manufacturing method of the steel sheet of the present embodiment uses the cleaning composition for steel sheet in the cleaning process, so that the cleaning process, the rinsing process, and the drying are performed even if the line speed is relatively low, for example, less than 500 m / min. It is possible to suppress the thickening of the oxide film of the steel sheet and the generation of rust in the process, and it is possible to suppress surface treatment defects such as plating and appearance defects due to rusting. Moreover, even if the said line speed is a comparatively high speed of 800 m / min or more, the manufacturing method of the steel plate of this embodiment has an effect. In particular, it is effective even when the cold-rolled steel sheet is cleaned at a high speed of 1 second or less. A general steel plate cleaning line is constructed in the order of immersion cleaning, brush cleaning, electrolytic cleaning, brush cleaning, rinsing, and drying. The length from immersion cleaning to drying is approximately 50 m, and when the line speed is 500 m / min, Cleaning is performed in an extremely short time of 6 seconds in the process. Among them, the electrolytic cleaning process is about 10 to 20 m, and when the line speed is 500 m / min, the calculation is about 1.2 to 2.4 seconds. The cleaning process according to the steel sheet manufacturing method of the present embodiment is also effective in electrolytic cleaning in such a short time or even in a shorter time, thereby increasing the cleaning line speed and improving the productivity. be able to. In addition, the line speed is preferably 10 m / min or more from the viewpoint of productivity and suppression of oxidation of the steel sheet.

The washing temperature in the washing step is preferably 20 ° C. or higher, more preferably 30 ° C. or higher, from the viewpoint of detergency, preferably 60 ° C. or lower, more preferably 50 ° C. or lower, from the viewpoint of reducing energy cost, 40 ° C. The following is more preferable. In addition, even if it is used at a high cleaning temperature such as 80 ° C., the cleaning performance and the antioxidant performance are not deteriorated.

The immersion time in the cleaning step is preferably 0.1 seconds or more, more preferably 0.5 seconds or more from the viewpoint of detergency, preferably 15 seconds or less, and more preferably 10 seconds or less from the viewpoint of productivity of the steel sheet. preferable.

Examples of the cleaning process in which the steel sheet cleaning composition of the present embodiment can be used include continuous cleaning, that is, immersion cleaning, spray cleaning, brush cleaning, electrolytic cleaning, and the like, such as oil stains such as rolling oil and iron powder. Solid dirt can be washed away. In the steel sheet cleaning composition of the present embodiment, the cleaning step is preferably immersion and electrolytic cleaning, and is suitable when the rolled steel sheet is passed through a roll in an alkaline immersion cleaning tank and an alkaline electrolytic cleaning tank. Applied. Electrolytic cleaning is a cleaning method in which the steel sheet is made positive (or negative) in the cleaning liquid and a direct current is passed through it. Oxygen (or hydrogen) bubbles generated from the steel sheet by the current are used, and oil stains attached to the steel sheet by physical force. It is a process of removing solid dirt such as iron powder.

In the electrolytic cleaning using the steel sheet cleaning composition of the present embodiment, the current density during the electrolytic cleaning is preferably 0.5 A / dm ² or more, more preferably 1 A / dm ² or more, from the viewpoint of detergency. From the viewpoint of reducing energy costs, 30 A / dm ² or less is preferable, and 20 A / dm ² or less is more preferable.

After the cleaning step, a rinsing step of rinsing the steel plate to be cleaned which has been immersed and cleaned with water can be provided. The conditions of the water temperature and the immersion time in the rinsing step can be adjusted as appropriate. The temperature of water in the rinsing step is preferably 5 ° C. or more, more preferably 15 ° C. or more from the viewpoint of cleaning properties and suppression of oxidation of the steel sheet, and 70 ° C. or less is preferable from the viewpoint of reducing energy costs, and 60 ° C. or less. More preferred. The immersion time is preferably 0.1 seconds or more, more preferably 0.5 seconds or more from the viewpoint of detergency, and preferably 15 seconds or less, more preferably 10 seconds or less, from the viewpoint of steel plate productivity.

The steel plate cleaning method of the present embodiment includes a drying step of drying the steel plate after the cleaning step and, if there is the rinsing step, in accordance with ordinary conditions. In the drying step, it is preferable to first perform a process of injecting a gas such as air onto the surface of the steel sheet to blow off moisture on the steel sheet. Examples of the drying means in the drying step include a method of putting in an oven at 80 ° C. or higher and 150 ° C. or lower, preferably 120 ° C. or lower, from the viewpoint of reducing energy costs. Moreover, the method of injecting gas, such as air adjusted to these temperatures, to the steel plate surface is mentioned. For example, the drying time is preferably 60 seconds or less, more preferably 40 seconds or less, and even more preferably 20 seconds or less from the viewpoint of reducing energy costs. In a production facility of a steel sheet factory, a method of heating at 80 ° C. or higher and 150 ° C. or lower, preferably 120 ° C. or lower, for 3 to 10 seconds and drying is exemplified.

The steel sheet obtained after washing can be used for various purposes such as automobile steel sheets, steel sheets for beverages such as canned goods, and steel sheets for household appliances. The amount of adhesion such as oil stains on the surface of the steel sheet after washing varies depending on the use of the steel sheet, but when the carbon adhesion mass of the steel sheet before washing is 100%, it is preferably 5% or less after washing, preferably 3% or less. It is more preferable that

The present invention further discloses the following production method, composition, or application regarding the above-described embodiment.
<1> 0.1% by mass or more and 6.0% by mass or less of alkali agent (component A), 0.01% by mass or more and 2.0% by mass or less of chelating agent (component B), surfactant (component C) 0.01% by mass or more and 2.0% by mass or less, a compound (component D) represented by the following general formula (I) 0.02% by mass or more and 5.0% by mass or less, and water (component E) A cleaning composition for steel sheets.

(In General Formula (I), R ₁ is a hydrogen atom or an alkyl group having 2 to 6 carbon atoms, and R ₂ is a hydrogen atom, a hydroxyethyl group, a hydroxypropyl group, an aminoethyl group, or 1 or more carbon atoms. 6 or less alkyl groups, and R ₃ is a hydroxyethyl group or a hydroxypropyl group.)
<2> The component A is one or more selected from the group consisting of alkali metal hydroxides, alkali metal silicates, alkali metal phosphates, alkali metal carbonates, and alkali metal borates. The steel sheet cleaning composition according to <1>, which is preferably present.
<3> The alkali metal hydroxide is preferably at least one selected from sodium hydroxide and potassium hydroxide, and the alkali metal silicate is sodium orthosilicate, sodium metasilicate, and sodium sesquisilicate. Preferably, the alkali metal phosphate is trisodium phosphate, and the alkali metal carbonate is disodium carbonate, sodium hydrogen carbonate, dipotassium carbonate. It is preferable that it is 1 or more types chosen from these, and it is preferable that the said borate of an alkali metal is sodium borate, The cleaning composition for steel plates as described in said <2>.
<4> The content of the component A is 0.1% by mass or more, preferably 0.2% by mass or more, more preferably 0.5% by mass or more, further preferably 1.0% by mass or more, 6 0.0 mass% or less, preferably 5.0 mass% or less, more preferably 4.0 mass% or less, still more preferably 3.5 mass% or less, and even more preferably 3.0 mass% or less. 1> to <3> The steel sheet cleaning composition according to any one of the above.
<5> The component B is preferably at least one selected from aldonic acid, aminocarboxylic acid, oxycarboxylic acid, and phosphonic acid, and alkali metal salts, lower amine salts, and alkanolamine salts, <1 > To <4> The steel sheet cleaning composition according to any one of the above.
<6> The aldonic acid is preferably at least one selected from gluconic acid, glucoheptonic acid, glyceric acid, tetronic acid, pentonic acid, hexonic acid, and heptonic acid, and the aminocarboxylic acid is nitrilotriacetic acid, ethylenediaminetetra One or more selected from acetic acid, ethylenediaminediacetic acid, and tetraethylenetetraminehexaacetic acid are preferred, the oxycarboxylic acid is preferably one or more selected from citric acid and malic acid, and the phosphonic acid is aminotrimethylene. The cleaning composition for steel sheet according to <5>, wherein at least one selected from phosphonic acid, hydroxyethylidene diphosphonic acid, ethylenediaminetetramethylenephosphonic acid, and diethylenetriaminepentamethylenephosphonic acid is preferable.
<7> The content of the component B is 0.01% by mass or more, preferably 0.02% by mass or more, more preferably 0.05% by mass or more, and further preferably 0.1% by mass or more. 0.0 mass% or less, preferably 1.5 mass% or less, more preferably 1.0 mass% or less, still more preferably 0.5 mass% or less, and even more preferably 0.3 mass% or less. 1> to <6> The steel sheet cleaning composition according to any one of the above.
<8> The steel sheet cleaning composition according to any one of <1> to <7>, wherein the component C is preferably a nonionic surfactant represented by the following general formula (II).
R ₄ —O — {(EO) n / (PO) m} —H (II)
(In the general formula (II), R ₄ is a hydrocarbon group having 8 to 18 carbon atoms, preferably an alkyl group, an alkenyl group or an alkylphenyl group, more preferably an alkyl group or an alkenyl group, and still more preferably an alkyl group. , R ₄ has preferably 10 or more, more preferably 12 or more, preferably 16 or less, more preferably 14 or less, EO is an ethyleneoxy group, PO is a propyleneoxy group, and n is an average addition of EO Number of moles, m is the average number of moles of PO added, n is 2 or more, preferably 5 or more, more preferably 8 or more, more preferably 12 or more, 20 or less, preferably 18 or less, 16 or less More preferably, m is 0 or more, 1 or more is preferable, 20 or less, 10 or less is preferable, 5 or less is more preferable, and 3 or less is more Preferably the al, addition form of PO and EO in {} is a random sequence may be either a block arrangement.)
<9> The steel sheet cleaning composition according to any one of <1> to <8>, wherein the component C is preferably a nonionic surfactant represented by the following general formula (III).
R ₅ —O— (EO) p (PO) q (EO) r—H (III)
(In the general formula (III), R ₅ is a hydrocarbon group having 8 to 18 carbon atoms, preferably an alkyl group, an alkenyl group or an alkylphenyl group, more preferably an alkyl group or an alkenyl group, and still more preferably an alkyl group. , R ₅ has preferably 10 or more, more preferably 12 or more, preferably 16 or less, more preferably 14 or less, EO is an ethyleneoxy group, PO is a propyleneoxy group, and p, q and r are Each is an average addition mole number of ethyleneoxy group, propyleneoxy group, and ethyleneoxy group, p is 1 or more, 2 or more are preferable, 4 or more are more preferable, 5 or more are further more preferable, and 15 or less are 12 The following is preferable, 10 or less is more preferable, q is 0 or more, 1 or more is preferable, 20 or less, 10 or less Preferably, 5 or less is more preferable, 3 or less is more preferable, r is 1 or more, 2 or more is preferable, 4 or more is more preferable, 5 or more is more preferable, 15 or less is preferable, 12 or less is preferable, 10 or less The steel sheet cleaning composition according to any one of <1> to <8>, wherein p + r is q or more and 20 or less and preferably greater than q.
<10> The content of the component C is 0.01% by mass or more, preferably 0.02% by mass or more, more preferably 0.03% by mass or more, and further preferably 0.05% by mass or more. 0.0 mass% or less, preferably 1.0 mass% or less, more preferably 0.5 mass% or less, still more preferably 0.3 mass% or less, and even more preferably 0.2 mass% or less. 1> to <9> The steel sheet cleaning composition according to any one of the above.
<11> The content of the component D is 0.02% by mass or more, preferably 0.03% by mass or more, more preferably 0.04% by mass or more, further preferably 0.05% by mass or more, and 0 .10% by mass or more is more preferable, 0.15% by mass or more is more preferable, 0.18% by mass or more is more preferable, 5.0% by mass or less, and 2.0% by mass or less is preferable. 1.0% by mass or less is more preferable, 0.5% by mass or less is more preferable, and 0.2% by mass or less is more preferable, and the steel sheet cleaning composition according to any one of <1> to <10>. .
<12> The component A is an inorganic alkali agent, the component B is at least one selected from aldonic acid, aminocarboxylic acid, oxycarboxylic acid, phosphonic acid, or alkali metal salts thereof, and the component C is non- The cleaning composition for steel sheet according to any one of <1> to <11>, wherein the cleaning composition is a ionic surfactant and the component D is at least one selected from the compounds represented by the general formula (I). object.
<13> The component A is at least one selected from sodium hydroxide, potassium hydroxide, sodium orthosilicate and sodium metasilicate, and the component B is selected from aldonic acid, aminocarboxylic acid or alkali metal salts thereof. It is at least one, the component C is a nonionic surfactant represented by the general formula (II), and the component D is at least one selected from the compounds represented by the general formula (I) More preferably, the component A is sodium hydroxide, the component B is an alkali metal salt of aldonic acid and aminocarboxylic acid, and the component C is a nonionic surfactant represented by the general formula (III). More preferably, the component D is at least one selected from the compounds represented by the general formula (I). 2> for a steel sheet detergent composition according to any one.
<14> The steel sheet cleaning composition according to any one of <1> to <13>, wherein the content of the component E is preferably 85.0% by mass or more, and preferably 99.86% by mass or less.
<15> A method for producing a steel sheet, comprising a cleaning step of cleaning the steel sheet using the steel sheet cleaning composition according to any one of <1> to <14>.
<16> The washing temperature in the washing step is preferably 20 ° C. or more, more preferably 30 ° C. or more, preferably 60 ° C. or less, more preferably 50 ° C. or less, and further preferably 40 ° C. or less, more preferably 40 ° C. or less. Steel plate manufacturing method.
<17> The immersion time in the washing step is preferably 0.1 seconds or more, more preferably 0.5 seconds or more, preferably 15 seconds or less, more preferably 10 seconds or less, in the above <15> or <16> The manufacturing method of the steel plate of description.
<18> The method for producing a steel sheet according to any one of <15> to <17>, wherein the cleaning step is preferably at least one of immersion cleaning, spray cleaning, brush cleaning, and electrolytic cleaning.
<19> The cleaning step is electrolytic cleaning, and the current density during electrolytic cleaning is preferably 0.5 A / dm ² or more, more preferably 1 A / dm ² or more, preferably 30 A / dm ² or less, 20 A / The method for producing a steel sheet according to any one of <15> to <18>, wherein dm ² or less is more preferable.
<20> The method for producing a steel plate according to any one of <15> to <19>, preferably including a rinsing step of rinsing the steel plate to be cleaned which has been immersed and cleaned after the cleaning step.
<21> The method for producing a steel plate according to any one of <15> to <19>, further including a drying step of drying the steel plate after the rinsing step after the cleaning step.
<22> A method for cleaning a steel sheet, comprising a cleaning step of cleaning the steel sheet using the steel sheet cleaning composition according to any one of <1> to <14>.
<23> The washing temperature in the washing step is preferably 20 ° C. or higher, more preferably 30 ° C. or higher, preferably 60 ° C. or lower, more preferably 50 ° C. or lower, and further preferably 40 ° C. or lower, described in <22>. Method for cleaning steel sheets.
<24> The immersion time in the washing step is preferably 0.1 seconds or more, more preferably 0.5 seconds or more, preferably 15 seconds or less, more preferably 10 seconds or less, in the above <22> or <23> A method for cleaning a steel sheet as described.
<25> The method for cleaning a steel sheet according to any one of <22> to <24>, wherein the cleaning step is preferably at least one of immersion cleaning, spray cleaning, brush cleaning, and electrolytic cleaning.
<26> The cleaning step is electrolytic cleaning, and the current density during electrolytic cleaning is preferably 0.5 A / dm ² or more, more preferably 1 A / dm ² or more, preferably 30 A / dm ² or less, 20 A / The method for cleaning a steel sheet according to any one of <22> to <25>, wherein dm ² or less is more preferable.
<27> Use of the composition according to any one of <1> to <14> for cleaning a steel sheet.

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

[Preparation of detergent for steel sheet]
<Examples 1 to 16 and Comparative Examples 1 to 14>
300 g of the detergent compositions of Examples 1 to 16 and Comparative Examples 1 to 14 were prepared by the following procedure so that the contents shown in Tables 1 and 2 were obtained. The numerical values described in Tables 1 and 2 represent the amount of the active ingredient, and the unit is mass%.
1. A chelating agent (component B) and water (component E) were added to a 300 ml glass beaker, mixed and stirred to obtain a mixed solution.
2. An alkali agent (component A) was added to the mixed solution obtained in 1 above and mixed and stirred to obtain a mixed solution.
3. A nonionic surfactant (component C) and a compound of general formula (I) (component D) were added to the mixed solution obtained in 2 above, mixed and stirred to obtain a test solution.

[Each component]
Each component described in Table 1 and Table 2 was as follows.
・ Component A (alkali agent)
Sodium hydroxide: manufactured by Tokuyama Corporation, liquid caustic soda (concentration 48% by mass)
・ Component B (chelating agent)
Sodium gluconate: manufactured by Fuso Chemical Industry Co., Ltd., sodium gluconate ethylenediaminetetraacetate sodium: manufactured by Nagase ChemteX Corporation, Clewat S2 (sodium ethylenediaminetetraacetate tetrahydrate)
・ Component C (surfactant)
Surfactant 1: Compound represented by the following general formula (IV) obtained by blocking addition of 7 mol of EO, 1.5 mol of PO and 7 mol of EO in this order to a mixed alcohol of lauryl alcohol and myristyl alcohol C ₁₂ H ₂₅ , C ₁₄ H ₂₉ _{_{-O- (EO) 7 - (PO}} ) 1.5 - (EO) 7 -H (IV)
(When the compound represented by the general formula (IV) is represented by the general formula (II), R ₄ is an alkyl group having 12 carbon atoms or an alkyl group having 14 carbon atoms, m is 14, and n is 1.5. And, when represented by the general formula (III), R ₅ is a linear alkyl group having 12 carbon atoms or a linear alkyl group having 14 carbon atoms, p is 7, q is 1.5, and r is 7.
Component D (compound represented by general formula (I))
N, N-diethylethanolamine: Nippon Emulsifier Co., Ltd., amino alcohol 2A
N, N-di-n-butylethanolamine: Nippon Emulsifier Co., Ltd., amino alcohol 2B
N-mono-n-butyldiethanolamine: Nippon Emulsifier Co., Ltd., amino alcohol MBD
N-mono-n-butylethanolamine: Nippon Emulsifier Co., Ltd., amino alcohol MBM
N-monomethylethanolamine: manufactured by Nippon Emulsifier Co., Ltd., amino alcohol MMA
N-monoethylethanolamine: manufactured by Nippon Emulsifier Co., Ltd., amino alcohol MEM
・ Component E (water)
Ion-exchanged water: Pure water of 1 μS / cm or less and other components manufactured with a pure water apparatus G-10DSTSET manufactured by Organo Corporation N, N-dimethylethanolamine: Amino alcohol 2 Mabs manufactured by Nippon Emulsifier Co., Ltd.
N-monomethyl diethanolamine: Nippon Emulsifier Co., Ltd., amino alcohol MDA
Triethylamine: Tokyo Chemical Industry Co., Ltd. N, N-diethylhydroxylamine: Tokyo Chemical Industry Co., Ltd. 1,3-diaminopropane: Tokyo Chemical Industry Co., Ltd. 1-Heptanol: Tokyo Chemical Industry Co., Ltd. 1-Pentanol: 3-methyl-1-butanol manufactured by Tokyo Chemical Industry Co., Ltd .: manufactured by Tokyo Chemical Industry Co., Ltd.

[Steel plate cleaning test]
〔Evaluation methods〕
<Steel to be cleaned>
A steel plate having a thickness of 0.2 mm that was cold-rolled with a synthetic ester-based rolling oil containing palm oil was cut into a size of 60 mm × 25 mm and used in a steel plate cleaning test. It was 230 mg / m < ² > as a result of measuring the carbon adhesion amount before washing | cleaning of the said steel plate by the method similar to the below-mentioned residual carbon adhesion amount measuring method.

<Cleaning test procedure>
After putting 300 g of the test solution in a 300 ml glass beaker, the test solution was heated to the cleaning temperature described in Tables 1 and 2. Next, a pair of iron electrode plates having a size of 100 mm in length and 50 mm in width (the distance between the electrodes was 20 mm) was installed in the cleaning agent. The steel plate to be cleaned was immersed in the center at an equal distance and between the electrodes for approximately 1 second, and then the steel plate potential was switched from negative to positive at a current density of 8 A / dm ² once every 0.35 seconds for electrolytic cleaning. After that, spray the steel plate with spray (pressure: 2 kgf / cm ² ) and spray hot water at 60 ° C. for 1 second, then dip rinse the steel plate with hot water at 60 ° C. for 5 seconds, put the steel plate into an empty 100 ml glass beaker, In addition, the whole steel plate was immersed in water, kept at 30 ° C. and maintained for 24 hours.

<Rust evaluation>
The surface of the steel sheet after the cleaning test was photographed, the rusted area was applied to a graph paper and calculated, and the average value of the five sheets was rounded to one decimal place. The results are shown in Table 1.

<Measurement of residual carbon adhesion>
A carbon / hydrogen / water analyzer (model number RC-612, manufactured by LECO) was used as an index of the amount of dirt adhered to the steel sheet surface, and the amount of carbon adhering to the steel sheet (residual carbon adhesion amount) was measured. The conditions of the apparatus are that the steel sheet is heated at 500 ° C., which is considered to burn dirt on the steel sheet below the softening temperature of iron, and the amount of carbon adhering to the steel sheet from CO ₂ generated by volatilization / pyrolysis or combustion is determined. I figured it out. The measurement was performed until the maximum intensity (maximum CO ₂ generation amount) peak was 100% and the intensity dropped to 1% or less. For the measurement, a steel plate after the rust test was used, and the two decimal places of the average value of the five sheets were rounded off. The results are shown in Tables 1 and 2.

Claims

The alkali agent (component A) is 0.1% by mass or more and 6.0% by mass or less, the chelating agent (component B) is 0.01% by mass or more and 2.0% by mass or less, and the surfactant (component C) is 0.00%. 01% by mass or more and 2.0% by mass or less, for steel sheet containing 0.02% by mass or more and 5.0% by mass or less of a compound (component D) represented by the following general formula (I) and water (component E) Cleaning composition.

(In General Formula (I), R 1 is a hydrogen atom or an alkyl group having 2 to 6 carbon atoms, and R 2 is a hydrogen atom, a hydroxyethyl group, a hydroxypropyl group, an aminoethyl group, or 1 or more carbon atoms. 6 or less alkyl groups, and R 3 is a hydroxyethyl group or a hydroxypropyl group.)
The cleaning composition of Claim 1 whose said component C is a nonionic surfactant shown to the following general formula (II).
R 4 —O — {(EO) n / (PO) m} —H (II)
(In the general formula (II), R 4 is a hydrocarbon group having 8 to 18 carbon atoms, EO is an ethyleneoxy group, PO is a propyleneoxy group, n is the average added mole number of EO, and m is the average of PO. Number of moles added, n is 2 or more and 20 or less, m is a number satisfying 0 or more and 20 or less, and the addition form of PO and EO in {} may be either random array or block array.)
The cleaning composition in any one of Claim 1 or 2 whose component C is a nonionic surfactant shown to the following general formula (III).
R 5 —O— (EO) p (PO) q (EO) r—H (III)
(In general formula (III), R 5 is a hydrocarbon group having 8 to 18 carbon atoms, EO is an ethyleneoxy group, PO is a propyleneoxy group, and p, q, and r are an ethyleneoxy group and a propyleneoxy group, respectively. The average added mole number of ethyleneoxy groups, p is 1 or more and 15 or less, q is 0 or more and 20 or less, r is a number satisfying 1 or more and 15 or less, and q ≦ p + r ≦ 20.
A steel sheet cleaning method comprising a cleaning step of cleaning a steel sheet using the steel sheet cleaning composition according to any one of claims 1 to 3.
A method for producing a steel sheet, comprising a cleaning step of cleaning the steel sheet using the steel sheet cleaning composition according to any one of claims 1 to 3.
Use of the composition according to any one of claims 1 to 3 for cleaning steel sheets.