JP5284609B2 - Non-electrolytically cleaned cold-rolled steel sheet detergent composition - Google Patents

Description

  The present invention relates to a detergent composition for cold-rolled steel sheets to be subjected to non-electrolytic cleaning. The detergent composition for cold-rolled steel sheets of the present invention is used for non-electrolytic cleaning of dirt on the surface of cold-rolled steel sheets.

  In the production of a metal steel plate, oil stains on the surface of the metal steel plate are degreased with an alkaline cleaner. Usually, the alkali detergent contains an alkali agent such as sodium hydroxide and a surfactant for emulsifying oil stains. In particular, when the oil stain is a rust preventive oil mainly composed of mineral oil or hydrocarbon, a high HLB nonionic surfactant having a high emulsifying power is used as a surfactant to remove these oil stains. Has been used. However, high HLB nonionic surfactants have a strong emulsifying power, but have high foaming properties, so that the alkaline detergent overflows from the washing tank due to foaming, which poses a major operational problem. In addition, the alkaline cleaning agent may need to function even at a low temperature from the viewpoint of energy efficiency.

In order to suppress foaming during the cleaning of the alkaline detergent, for example, the content of the alkaline agent in the detergent is set to a high concentration of 3.5% by weight or more, and the nonionic surfactant that is a foaming factor is a salt. A technique for suppressing bubbles by making use of easy analysis is disclosed (Patent Document 1). On the other hand, it is disclosed that a polyoxyalkylene alkyl ether in which the ratio of oxyethylene group and oxypropylene group is controlled within a specific range is used as a nonionic surfactant for a detergent composition that is good for low-temperature cleaning (patent) Reference 2). Further, it is disclosed that polyoxyalkylene alkyl ether is used as a nonionic surfactant and octyliminodipropionate is used as a solubilizer (Patent Document 3).
JP-A-5-320962 JP-A-11-222687 JP 2006-525408 A

  However, in Patent Document 1, since the alkali agent is excessively added, the foam suppression property at a low temperature (50 ° C. or lower) becomes insufficient, and in addition, the cleanability at a low temperature is not sufficient. Also in Patent Documents 2 and 3, the specifically disclosed cleaning agents do not have sufficient antifoaming properties at low temperatures. Compared to the conventional cleaning conditions for metal steel sheets disclosed in Patent Documents 1 to 3, along with the continuous improvement in production speed of metal steel sheets, especially in cold rolled steel sheets that are subjected to non-electrolytic cleaning, Inhibition of detergency and further improvement of low-temperature detergency have become major issues.

  INDUSTRIAL APPLICABILITY The present invention can be used for non-electrolytic cleaning of cold-rolled steel sheets, particularly for non-electrolytic cleaning of stainless steel sheets that are not suitable for electrolytic cleaning, and even at low temperatures (50 ° C. or lower). The present invention provides a detergent composition for cold-rolled steel sheets that is non-electrolytically cleaned and has both the cleanability and the foam-suppressing property, and the surface of the cold-rolled steel sheet using the detergent composition for cold-rolled steel sheets. It aims at providing the manufacturing method of the cold rolling steel plate using the washing | cleaning method and the said washing | cleaning method.

That is, the present invention
Contains alkali agent (a), nonionic surfactant (b), chelating agent (c) {however, excluding aliphatic carboxylic acid or its salt (d) from chelating agent (c)} and water (A) A detergent composition for cold-rolled steel sheet to be non-electrolytically cleaned,
Nonionic surfactant (b)
The following general formula (1): R ¹ —O — {(EO) _m / (PO) _n } H (1)
(R ¹ is a decyl group having a branched chain, EO is an oxyethylene group, PO is an oxypropylene group, m is an average addition mole number of the oxyethylene group, n is an average addition mole number of the oxypropylene group, and And 0 <m ≦ 20, 0 <n ≦ 20), and a polyoxyethylene polyoxypropylene alkyl ether represented by
In the cleaning liquid containing water (A) at the time of use, the composition is
The content of component (a) is 0.1 to 1% by weight,
The content of component (b) is 0.001 to 2% by weight,
The present invention relates to a detergent composition for cold-rolled steel sheet that is subjected to non-electrolytic cleaning, wherein the content of component (c) is 0.01 to 1% by weight.

  Further, the present invention provides a cleaning of the surface of a cold-rolled steel sheet having a non-electrolytic cleaning step using the cleaning composition for a cold-rolled steel sheet that is subjected to non-electrolytic cleaning to remove dirt on the surface of the cold-rolled steel sheet that is the object to be cleaned. Method.

Further, the present invention is a method for producing a cold rolled steel sheet comprising a step of cold rolling a steel sheet in the presence of rolling oil, and a step of non-electrolytically washing the rolling oil adhering to the rolled steel sheet with a cleaning agent. ,
In the said washing | cleaning process, it is related with the manufacturing method of the cold rolled steel plate which uses the said cleaning composition for cold rolled steel plates as a cleaning agent.

  The present invention has a good cleaning property against oil stains adhering to the surface of a cold-rolled steel sheet even at a low temperature (50 ° C. or less), and has a foam-suppressing property and is a non-electrolytically cleaned cold. A detergent composition for hot-rolled steel sheets can be provided.

  Moreover, the said detergent composition for cold-rolled steel plates can provide the method of manufacturing a cold-rolled steel plate with good cleanability and suppression of foaming and good operability even at low temperatures.

  As the alkaline agent (a) used in the present invention, any water-soluble alkaline agent can be used in order to ensure the removal of oil stains. Specific examples include hydroxides of alkali metals such as sodium hydroxide and potassium hydroxide, silicates such as sodium orthosilicate, sodium metasilicate and sodium sesquisilicate, phosphates such as trisodium phosphate, disodium carbonate And carbonates such as sodium hydrogen carbonate and dipotassium carbonate, and borate salts such as sodium borate. Two or more water-soluble alkaline agents may be combined. Sodium hydroxide, potassium hydroxide, sodium orthosilicate and sodium metasilicate are preferred, and sodium hydroxide and potassium hydroxide are more preferred.

The nonionic surfactant (b) used in the present invention is a polyoxyethylene polyoxypropylene alkyl ether represented by the general formula (1). R ^{1 in} the formula is a decyl group having a branched chain from the viewpoint of good detergency and foam suppression at low temperatures. When R ¹ is a straight chain, even if it is an alkyl group having 10 carbon atoms, foam suppression cannot be satisfied. In addition, even when polyoxyethylene polyoxypropylene alkyl ether having a decyl group having a branched chain as R ¹ is used, when polyoxyethylene polyoxypropylene alkyl ether having another alkyl group is mixed , Cleaning properties and foam suppression cannot be satisfied. Examples of the decyl group having a branched chain include an isodecyl group, a sec-decyl group, a tert-decyl group, and the like. Among these, an isodecyl group is preferable.

The oxyethylene group and the oxypropylene group have a distribution depending on the number of added moles, but from the viewpoint of good detergency and foam suppression at a low temperature, the average number of added moles of oxyethylene group: m satisfies 0 <m ≦ 20. Satisfactory, the average added mole number of oxypropylene group: n is a number satisfying 0 <n ≦ 20. The average added mole number of the oxyethylene group: m is preferably 1 ≦ m ≦ 10, more preferably 3 ≦ m ≦ 8. The average added mole number of oxypropylene group: n is preferably 2 ≦ n ≦ 15, more preferably 3 ≦ n ≦ 12. Furthermore, the sum (m + n) of the average addition mole number of oxyethylene groups: m and the average addition mole number of oxypropylene groups: n is 4 ≦ (m + n) ≦ 30, more preferably 8 ≦ (m + n) ≦ 18, It is preferable to satisfy {(EO) _m / (PO) _n } in the general formula (1) indicates that the arrangement of the oxyethylene group and the oxypropylene group is not limited, and may be a block body or a random body. The arrangement of the oxyethylene group and the oxypropylene group is preferably a block body from the viewpoint of foam suppression, and more preferably the oxyethylene group is adjacent to an oxygen atom.

  The chelating agent (c) used in the present invention is believed to act on soils such as iron soap to chelate iron ions and the like, to make fatty acid soap easier to dissolve the soil, and to improve the detergency. . However, the chelating agent (c) is a concept excluding the aliphatic carboxylic acid or its salt (d). Examples of the chelating agent (c) include aldonic acids such as gluconic acid, glucoheptonic acid, glyceric acid, tetronic acid, pentonic acid, hexonic acid and heptonic acid, or alkali metal salts thereof or lower amine salts having 1 to 4 carbon atoms; Alkali metal salt or lower amine salt of aminocarboxylic acid such as acetic acid, ethylenediaminetetraacetic acid, ethylenediaminediacetic acid, tetraethylenetetraminehexaacetic acid; alkali metal salt or lower amine salt of citric acid, malic acid or the like or oxycarboxylic acid thereof; amino Phosphonic acids such as trimethylenephosphonic acid, hydroxyethylidenediphosphonic acid, ethylenediaminetetramethylenephosphonic acid, diethylenetriaminepentamethylenephosphonic acid, or alkali metal salts or lower amine salts thereof; Ethanol amines, alkanol amine salts such as triethanolamine. As these chelating agents (c), aldonic acid or a salt thereof is preferable, and an alkali metal salt or a lower amine salt is preferable. Of these, alkali metal salts or lower amine salts of gluconic acid and glucoheptonic acid, particularly sodium gluconate are preferred. At least one chelating agent (c) may be used, and two or more chelating agents may be used in combination.

  The detergent composition for cold-rolled steel sheets of the present invention comprises an alkaline agent (a), a nonionic surfactant (b) which is a polyoxyethylene polyoxypropylene alkyl ether represented by the general formula (1), a chelating agent ( It is prepared by further adding water (A) to c). Furthermore, arbitrary additives can be added.

  The detergent composition for cold-rolled steel sheet of the present invention preferably contains an aliphatic carboxylic acid or a salt thereof (d) from the viewpoint of ensuring stability during storage and stability of effects after storage. .

The aliphatic carboxylic acid or a salt thereof (d) used in the present invention is a thickening agent as a solubilizing agent for allowing the cold-rolled steel sheet detergent composition of the present invention to exhibit suitable detergency in use. Even when stored as a composition, the concentrated composition ensures a uniform and transparent concentrated state in a wide temperature range so as to express suitable detergency when it is finally diluted with water (A). Used as a solubilizer. As the aliphatic carboxylic acid or a salt thereof (d),
The following general formula (2): R ² -COOM ¹ (2)
(R ² represents a branched aliphatic hydrocarbon group having 3 to 14 carbon atoms, M ¹ represents a hydrogen atom, an alkali metal, an aliphatic ammonium group having 1 to 4 carbon atoms, ammonium, or a mono-, di- or trialkanol ammonium. ) Or a salt thereof (d1) represented by the following general formula (3): R ³ —COOM ² (3)
(R ³ represents a linear aliphatic hydrocarbon group having 1 to 14 carbon atoms, M ² represents a hydrogen atom, an alkali metal, an aliphatic ammonium group having 1 to 4 carbon atoms, ammonium, or a mono-, di- or trialkanol ammonium. A straight-chain aliphatic carboxylic acid represented by (shown) or a salt thereof (d2). Combining the component (d1) and the component (d2) at a constant ratio can ensure a uniform and transparent thick state in a wide temperature range with a small amount of solubilizing agent. From the viewpoint of

In the general formula (2), the branched aliphatic hydrocarbon group represented by R ² is an alkyl group or an alkenyl group having a branched chain having 3 to 14 carbon atoms. Among these branched aliphatic hydrocarbon groups, an alkyl group having 4 to 12 carbon atoms is preferable, and an alkyl group having 5 to 10 carbon atoms is more preferable.

In the general formula (3), the linear aliphatic hydrocarbon group represented by R ³ is an alkyl group or an alkenyl group having a straight chain of 1 to 14 carbon atoms. Among these linear aliphatic hydrocarbon groups, an alkyl group having 3 to 12 carbon atoms is preferable, and an alkyl group having 4 to 10 carbon atoms is more preferable.

M ¹ and M ² in the aliphatic carboxylic acid represented by the general formula (2) and the general formula (3) or a salt thereof (d) are a hydrogen atom, an alkali metal, an aliphatic ammonium having 1 to 4 carbon atoms, Ammonium or mono-, di- or trialkanol ammonium. Examples of the alkali metal include potassium and sodium. Examples of the aliphatic ammonium include methylammonium, ethylammonium, propylammonium, butylammonium, ethylenediammonium, diethylenetriammonium and the like. Examples of the alkanolammonium include Monoethanolammonium, diethanolammonium, triethanolammonium, and other alkanol ammoniums having 3 to 10 carbon atoms.

  Each component in the cleaning composition for cold-rolled steel sheet according to the present invention has the following content from the viewpoint of ensuring cleaning properties and foam suppression properties during cleaning.

  The content of component (a) is 0.1 to 1% by weight, more preferably 0.2 to 0.7% by weight. The content of component (b) is 0.001 to 2% by weight, preferably 0.005 to 2% by weight, more preferably 0.005 to 1% by weight, and still more preferably 0.005 to 0%. .1% by weight. Moreover, content of a component (c) is 0.01 to 1 weight%, Preferably it is 0.02 to 0.5 weight%, More preferably, it is 0.03 to 0.4 weight%.

  The content of the component (b) is preferably 0.005 to 2 parts by weight, more preferably 0.005 to 0.4 parts by weight with respect to 1 part by weight of the component (a) based on the component (a). Parts, more preferably 0.01 to 0.3 parts by weight.

  The content of the component (c) is preferably 0.005 to 1 part by weight, more preferably 0.01 to 0.8 part by weight with respect to 1 part by weight of the component (a) based on the component (a). Parts, more preferably 0.05 to 0.6 parts by weight.

  When the component (d1) is contained, the content thereof is preferably 0.01 to 0.5 parts by weight, more preferably 0.8 parts per 1 part by weight of the component (a) based on the component (a). It is 02 to 0.4 part by weight, more preferably 0.04 to 0.3 part by weight.

  When the component (d2) is contained, the content thereof is preferably 0.01 to 0.5 parts by weight, more preferably 0.8 parts per 1 part by weight of the component (a) based on the component (a). It is 02-0.4 weight part, More preferably, it is 0.03-0.3 weight part.

  The detergent composition for cold-rolled steel sheet of the present invention is water that is a component (a) to (d) and (A) from the viewpoint of ensuring stability during storage and stability of effects after storage. It is preferable to use the product containing the same as it is or diluted with water. From the same viewpoint, the composition contains components (a) to (d) and water, and the total content of components (a) to (d) in the composition is the same as that of the present invention at the time of use. It is more preferable to prepare a composition (hereinafter referred to as a concentrated composition) that is higher than the composition for cold rolled steel sheet, dilute the concentrated composition with water, and use it for washing the cold rolled steel sheet.

  When the concentrated composition is used as a cleaning liquid from the viewpoint of ensuring cleaning properties and foam suppression properties even at low temperatures, the components (a) to (d) are in the following ratios: Thus, it is diluted with water as component (A).

  The content of component (a) is 0.1 to 1% by weight, more preferably 0.2 to 0.7% by weight. The content of component (b) is 0.001 to 2% by weight, preferably 0.005 to 2% by weight, more preferably 0.005 to 1% by weight, and still more preferably 0.005 to 0%. .1% by weight. Moreover, content of a component (c) is 0.01 to 1 weight%, Preferably it is 0.02 to 0.5 weight%, More preferably, it is 0.03 to 0.4 weight%. The content of component (d1) is 0.005 to 5% by weight, preferably 0.01 to 1% by weight, more preferably 0.01 to 0.08% by weight, and still more preferably 0.01. -0.06% by weight. The content of component (d2) is 0.005 to 5% by weight, preferably 0.01 to 1% by weight, more preferably 0.01 to 0.08% by weight, and still more preferably 0.01. -0.06% by weight.

  In addition, it is preferable that the ratio of a concentrated composition is mix | blended on the basis of a component (a).

  The content of the component (b) is preferably 0.005 to 0.5 parts by weight, more preferably 0.005 to 0.005 parts per 1 part by weight of the component (a) based on the component (a). 4 parts by weight, more preferably 0.01 to 0.3 parts by weight.

  The content of the component (c) is preferably 0.005 to 1 part by weight, more preferably 0.01 to 0.8 part by weight with respect to 1 part by weight of the component (a) based on the component (a). Parts, more preferably 0.05 to 0.6 parts by weight.

  When the component (d1) is contained, the content thereof is preferably 0.01 to 0.5 parts by weight, more preferably 0.8 parts per 1 part by weight of the component (a) based on the component (a). It is 02 to 0.4 part by weight, more preferably 0.04 to 0.3 part by weight.

  When the component (d2) is contained, the content thereof is preferably 0.01 to 0.5 parts by weight, more preferably 0.8 parts per 1 part by weight of the component (a) based on the component (a). It is 02-0.4 weight part, More preferably, it is 0.03-0.3 weight part.

  The water that is the component (A) is preferably deionized water. The concentration in the cleaning composition can be controlled by water. The concentrated composition can be further diluted with water during washing. In addition, each component may be premixed in one or two liquids at the time of cleaning, and diluted before use in a cleaning tank. It may be diluted.

  Furthermore, the cleaning composition for cold rolled steel sheets of the present invention generally uses additives such as organic builders that improve cleaning properties, taking into account chemical oxygen demand (COD) and cost increases. Furthermore, it is possible to mix | blend.

  The cleaning composition for cold-rolled steel sheets of the present invention is used for cleaning and removing dirt on the surface of cold-rolled steel sheets, which are various objects to be cleaned, by non-electrolytic cleaning. The cold-rolled steel sheet is particularly suitable for a stainless steel sheet that is suitable for non-electrolytic cleaning that avoids etching of the surface of the steel sheet. Among non-electrolytic cleanings, it is effective for immersion cleaning, spray cleaning, and brush cleaning, and particularly effective for spray cleaning and brush cleaning, which often involves foaming during cleaning.

  The cleaning composition for cold-rolled steel sheets of the present invention is usually used in a cleaning temperature range of 30 to 80 ° C., but the cleaning composition for cold-rolled steel sheets of the present invention has a cleaning temperature of 50 ° C. Even at the following low temperatures, the detergency is good and the antifoaming property can be maintained. The washing temperature is preferably 20 to 50 ° C, more preferably 30 to 50 ° C, and still more preferably 35 to 50 ° C.

  Further, in the present invention, a method for cleaning a surface of a cold-rolled steel sheet, which has a non-electrolytic cleaning step by using the detergent composition for a cold-rolled steel sheet according to the present invention, for contamination of the surface of the cold-rolled steel sheet that is an object to be cleaned, I will provide a.

  In the method for cleaning the surface of the cold rolled steel sheet, the cleaning temperature is usually in the range of 30 to 80 ° C., but in the cleaning method of the present invention, the cleaning composition for cold rolled steel sheet of the present invention is used. Therefore, even when the washing temperature is as low as 50 ° C. or less, the washing property is good and the foam suppression property can be maintained. The washing temperature is preferably 20 to 50 ° C, more preferably 30 to 50 ° C, and still more preferably 35 to 50 ° C.

  In the method for cleaning the surface of the cold-rolled steel sheet, the cleaning composition for cold-rolled steel sheet of the present invention is such that the component (a) to the component (c) have the predetermined concentration when used as a cleaning liquid. And dissolved in water (A). The cleaning composition for cold-rolled steel sheets of the present invention may be prepared in advance or may be prepared when the concentrated composition is used as a cleaning liquid. Usually, a concentrated composition of a cleaning composition for cold-rolled steel sheets containing the component (a) to component (c) or the component (a) to component (d) is prepared, and this is used as a cleaning liquid. When used as a liquid, it is appropriately diluted with water (A). The degree of dilution at the time of dilution can be appropriately set. The content of the component (a) is 0.1 to 1% by weight, the content of the component (b) is 0.001 to 2% by weight, When the content of (c) is 0.01 to 1% by weight, and the component (d1) and the component (d2) are included, the content of the component (d1) is 0.005 to 5% by weight, Dilute so that the content of (d2) is 0.005 to 5% by weight.

  Moreover, in this invention, the manufacturing method of the cold rolled steel plate including the process of cold-rolling a steel plate in presence of rolling oil, and the process of carrying out the nonelectrolytic washing | cleaning of the rolling oil adhering to the rolled steel plate with a washing | cleaning agent is provided. . In the washing step in the method for producing a cold-rolled steel sheet, in the cleaning step, the surface of the cold-rolled steel sheet that is the object to be cleaned is contaminated with a non-electrolytic cleaning step using the cleaning composition for cold-rolled steel sheet of the present invention. A method of cleaning the surface of a cold-rolled steel sheet having the following is used. That is, the cleaning composition for cold-rolled steel sheet of the present invention is used as a cleaning agent for cleaning and removing the rolling oil adhering to the rolled steel sheet after cold-rolling the steel sheet in the presence of rolling oil. . As described above, the washing temperature is usually 30 to 80 ° C., but is suitable even at a low temperature of 50 ° C. or less. The cold-rolled steel sheet detergent composition is used for continuous cleaning of cold-rolled steel sheets (steel strips) at steelworks, etc., particularly when performing non-electrolytic cleaning, and has a small amount of residual oil. It is possible to efficiently produce a cold-rolled steel sheet while suppressing foaming. Further, in the step of non-electrolytic cleaning in the manufacturing method of the cold-rolled steel sheet, as described in the method for cleaning the surface of the cold-rolled steel sheet, the concentrated composition of the detergent composition for cold-rolled steel sheet that is non-electrolytically cleaned A solution prepared by diluting with water (A) can be suitably used.

  The cleaning composition for cold-rolled steel sheets of the present invention is effective for non-electrolytic cleaning with preferred examples of immersion cleaning, spray cleaning, and brush cleaning, and particularly spray cleaning and brush cleaning that often involve bubbles during cleaning. The case where it applies to is preferable.

<Detergency>
(1) Steel plate to be cleaned Cold-rolled steel plate (60 mm long x 25 mm wide) obtained by washing the oil adhering to the surface with n-hexane, n-hexane solution (oil 0.5 g / hexane) with a constant concentration of oil 250 ml). The steel plate pulled up after the immersion was dried, and n-hexane was further evaporated to obtain a cleaning sample. The amount of oil adhered to the washed sample is 100 mg / m ² .

(2) Cleaning test 1
The sample was sequentially subjected to spray cleaning, spray rinsing and drying.
Spray cleaning: Using a nozzle (VVP9030, manufactured by Ikeuchi Co., Ltd.), temperature: 40 ° C. or 50 ° C., pressure: 0.2 MPa, flow rate: 0.04 (L / sec), time: 2 seconds, spray cleaning . The temperature of the test cleaning solution is shown in Table 1.
Spray rinsing: Spray rinsing was performed using a nozzle (VVP9030, manufactured by Ikeuchi Co., Ltd.) at a temperature of 70 ° C., a pressure of 0.1 MPa, a flow rate of 0.3 (L / sec), and a time of 2 seconds.
Drying: performed at 120 ° C. for 10 seconds.

(2) Cleaning test 2
The sample was sequentially subjected to spray cleaning, brush cleaning, hot water brush cleaning, spray rinsing, and drying.
Spray cleaning: Using a nozzle (VVP9030, manufactured by Ikeuchi Co., Ltd.), temperature: 40 ° C. or 50 ° C., pressure: 0.2 MPa, flow rate: 0.04 (L / sec), time: 2 seconds, spray cleaning . The temperature of the test cleaning solution is shown in Table 1.
Brush cleaning: Brush roll cleaning tester with 40 ° C or 50 ° C cleaning liquid (manufactured by Showa Kogyo Co., Ltd., nylon brush, brush rotation speed 300 rpm, brush reduction 1 mm, steel plate feed speed 50 m / min, liquid volume 4 L / min) The brush was washed once.
Hot water brush cleaning: Brush roll tester using water adjusted to 70 ° C. (made by Showa Kogyo Co., Ltd., nylon brush, brush rotation speed 300 rpm, brush reduction 1 mm, steel plate feed speed 50 m / min, liquid volume 4 L / min) The brush was washed once.
Spray rinsing: Spray rinsing was performed using a nozzle (VVP9030, manufactured by Ikeuchi Co., Ltd.) at a temperature of 70 ° C., a pressure of 0.1 MPa, a flow rate of 0.3 (L / sec), and a time of 2 seconds.
Drying: performed at 120 ° C. for 10 seconds.

(3) Method for measuring amount of residual adhered oil The amount of adhered oil on the steel plate after the cleaning test was measured using a steel plate adhered oil amount measuring device EMIA-111 (manufactured by Horiba, Ltd.). The measured value is an average value of five measurements. Evaluation criteria for cleaning of the cleaning test 1, the residual adhesion oil amount after the measurement is preferably less than 3-10 mg / m ^2, less than 3 mg / m ² is more preferable. Evaluation criteria for cleaning of the cleaning test 2 remains adhered oil amount after the measurement is preferably less than 1 - 2.5 mg / m ^2, less than 1 mg / m ² is more preferable.

<Bubbling property>
After putting 60 ml of the cleaning solution set to the washing temperature in each case into a 200 ml cylinder, the cylinder was shaken up and down 20 times. The bubble height was measured immediately after the end of the strong shaking and after 1 minute. The bubble height is preferably 10 to less than 20 ml, more preferably less than 0 to 10 ml, immediately after. The bubble height after 1 minute is preferably less than 10 to 20 ml, more preferably less than 0 to 2 m.

<Product stability of concentrated composition>
The transparency of the concentrated composition obtained by concentrating the cleaning liquid of each example by 6.6 times was examined.

Example 1
Sodium hydroxide 0.45% by weight,
Polyoxyethylene polyoxypropylene isodecyl ether (average addition mole number of polyoxyethylene is 6 mole, average addition mole number of polyoxypropylene is 8 mole) 0.03% by weight,
0.06% by weight sodium gluconate,
And the cleaning composition which consists of balance water (a balance amount uses deionized water) was prepared, and the washing | cleaning property test and the foaming property test were done on the washing | cleaning temperature conditions shown in Table 1. The results are shown in Table 1.

Examples 2 and 3 and Comparative Examples 1 and 2
Cleaning in the same manner as in Example 1 except that the type of nonionic surfactant (b) or the ratio of each component, the temperature of the cleaning property test and the foaming property test were changed as shown in Table 1. An agent composition was prepared. In Example 3 and Comparative Example 2, the component (d1) and the component (d2) are further added to the cleaning composition in the proportions shown in Table 1 as the aliphatic carboxylic acid or salt (d) thereof. Table 1 shows the results of the washing evaluation and the foamability test.

Example 4
Prepare a concentrated composition in advance, leave the concentrated composition at 50 ° C. for 24 hours, dilute it 6.6 times,
Sodium hydroxide 0.45% by weight,
Polyoxyethylene polyoxypropylene isodecyl ether (average addition mole number of polyoxyethylene is 6 mole, average addition mole number of polyoxypropylene is 8 mole) 0.01% by weight,
0.06% by weight sodium gluconate,
0.03% by weight of 2-ethylhexanoic acid,
n-octanoic acid (Lunac 8-98, manufactured by Kao Corporation) 0.02% by weight,
And a detergent composition comprising the remaining water (the balance is deionized water).

Examples 5-10, Comparative Examples 3-10
Cleaning in the same manner as in Example 3 except that the type of nonionic surfactant (b) or the ratio of each component, the temperature of the detergency test and the foamability test were changed as shown in Table 1 in Example 3. An agent composition was prepared. Table 1 shows the results of the washing evaluation and the foamability test.

  In addition, the measurement of the average addition mole number of the oxyethylene group and the oxypropylene group in the nonionic surfactant (b) shown in Table 1 was 3% by weight of the predetermined nonionic surfactant (b) in isopropyl alcohol. The dissolved material was used as a sample, and the following apparatus and column measurement conditions were used.

In addition, the nonionic surfactant (b) used in each example is
Finesurf IDEP-608 manufactured by Aoki Yushi Co., Ltd .: polyoxyethylene (6) polyoxypropylene (8) isodecyl ether (average number of moles added to the value in parentheses; the same shall apply hereinafter);
Fine Surf IDEP-604 manufactured by Aoki Yushi Co., Ltd .: polyoxyethylene (6) polyoxypropylene (4) isodecyl ether;
Wonder Surf ID-70 manufactured by Aoki Yushi Co., Ltd .: polyoxyethylene (7) isodecyl ether;
New Coal 1004 manufactured by Nippon Emulsifier Co., Ltd .: Polyoxyethylene (4) -2-ethylhexyl ether added with 2 mol of polyoxypropylene;
Sample made by Nippon Emulsifier Co., Ltd .: polyoxyethylene (8) polyoxypropylene (4) -n-decyl ether;
It is a polyoxyethylene (9) polyoxypropylene (5) adduct of Sophanol EP9050 manufactured by Nippon Shokubai Co., Ltd .: sec-C12-14 alcohol mixture.
When the nonionic surfactant (b) exemplified above has an oxyethylene group and an oxypropylene group, their arrangement is all a block body, and the oxyethylene block body has a structure adjacent to an oxygen atom.

  From the results in Table 1, the cleaning composition of the present invention was diluted with water once the concentrated composition was prepared even when the cleaning composition of the present invention was directly prepared (Examples 1 and 2). Even in the case (Examples 3 to 10), it can be seen that the cleanability and the antifoaming property can be satisfied even at a low temperature of 50 ° C. or less. On the other hand, since the cleaning composition of Comparative Examples 1 to 10 does not satisfy each component or content of the cleaning composition of the present invention, it satisfies both cleaning performance and foam suppression performance at a low temperature of 50 ° C. or lower. It is not a thing. The 6.6-fold concentrated system concentrated compositions of Examples 1 and 2 and Comparative Examples 1 and 2 were cloudy and separated, but Examples 3 to 10 containing an aliphatic carboxylic acid or a salt thereof (d) and The 6.6-fold concentrated system concentrated compositions of Comparative Examples 3 to 10 were transparent. In Comparative Example 10, the chelating agent (c) of the present invention is not used, and the amount used as a solubilizer for maintaining the stability of the product is large, and any evaluation performance deteriorates.

Claims (10)

Contains alkali agent (a), nonionic surfactant (b), chelating agent (c) {however, excluding aliphatic carboxylic acid or its salt (d) from chelating agent (c)} and water (A) A detergent composition for cold-rolled steel sheet to be non-electrolytically cleaned,
Nonionic surfactant (b)
The following general formula (1): R ¹ —O — {(EO) _m / (PO) _n } H (1)
(R ¹ is a decyl group having a branched chain, EO is an oxyethylene group, PO is an oxypropylene group, m is an average addition mole number of the oxyethylene group, n is an average addition mole number of the oxypropylene group, and And 0 <m ≦ 20, 0 <n ≦ 20), and a polyoxyethylene polyoxypropylene alkyl ether represented by
In the cleaning liquid containing water (A) at the time of use, the composition is
The content of component (a) is 0.1 to 1% by weight,
The content of component (b) is 0.001 to 2% by weight,
A detergent composition for cold-rolled steel sheets to be subjected to non-electrolytic cleaning, wherein the content of component (c) is 0.01 to 1% by weight.   The cleaning composition for a cold rolled steel sheet to be subjected to non-electrolytic cleaning according to claim 1, wherein the steel sheet is a stainless steel sheet.   The chelating agent (c) in the composition is gluconic acid or a salt thereof. The cleaning composition for a cold rolled steel sheet to be subjected to non-electrolytic cleaning according to claim 1 or 2.   The cleaning composition for cold-rolled steel sheets subjected to non-electrolytic cleaning according to any one of claims 1 to 3, wherein the cleaning temperature is 50 ° C or lower. And further having an aliphatic carboxylic acid or a salt thereof (d),
Aliphatic carboxylic acid or a salt thereof (d)
The following general formula (2): R ² -COOM ¹ (2)
(R ² represents a branched aliphatic hydrocarbon group having 3 to 14 carbon atoms, M ¹ represents a hydrogen atom, an alkali metal, an aliphatic ammonium group having 1 to 4 carbon atoms, ammonium, or a mono-, di- or trialkanol ammonium. A branched aliphatic carboxylic acid or a salt thereof (d1) represented by:
The following general formula (3): R ³ —COOM ² (3)
(R ³ represents a linear aliphatic hydrocarbon group having 1 to 14 carbon atoms, M ² represents a hydrogen atom, an alkali metal, an aliphatic ammonium group having 1 to 4 carbon atoms, ammonium, or a mono-, di- or trialkanol ammonium. The detergent composition for cold-rolled steel sheets subjected to non-electrolytic cleaning according to any one of claims 1 to 4, comprising a linear aliphatic carboxylic acid represented by the formula (1) or a salt thereof (d2).   The surface of the cold-rolled steel sheet, which is the object to be cleaned, has a non-electrolytic cleaning step with the detergent composition for cold-rolled steel sheet to be subjected to non-electrolytic cleaning according to any one of claims 1 to 5, A method for cleaning the surface of a rolled steel sheet.   The method for cleaning a surface of a cold-rolled steel sheet according to claim 6, wherein the cleaning temperature is 50 ° C or lower. The non-electrolytically cleaned cold rolled steel sheet detergent composition used in the nonelectrolytic cleaning step is a non-electrolytically cleaned cold rolled steel sheet detergent composition according to claim 5, It was prepared by diluting with (A),
In the cleaning liquid containing the diluted water (A) at the time of use, the composition is
The content of component (a) is 0.1 to 1% by weight,
The content of component (b) is 0.001 to 2% by weight,
The content of component (c) is 0.01 to 1% by weight,
The content of the component (d1) is 0.005 to 5% by weight,
The content of the component (d2) is 0.005 to 5% by weight,
The method for cleaning a surface of a cold-rolled steel sheet according to claim 6 or 7, wherein the method is adjusted. A method for producing a cold rolled steel sheet, comprising a step of cold rolling a steel sheet in the presence of rolling oil, and a step of non-electrolytically washing the rolling oil adhering to the rolled steel sheet with a cleaning agent,
In the said washing | cleaning process, the manufacturing method of the cold rolled steel plate using the cleaning composition for cold rolled steel plates by which the nonelectrolytic washing in any one of Claims 1-5 is carried out.   A method for manufacturing a cold-rolled steel sheet, comprising a step of non-electrolytic cleaning by the cleaning method according to claim 8.