JPS6259183B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a detergent having lubricating properties that can be sprayed in place of rolling oil at the final stand of a tandem rolling mill to obtain rolled steel sheets with extremely little residue on the surface of the steel sheets after cold rolling. . In recent years, cold-rolled steel sheets have usually been cleaned in an electrolytic cleaning line before annealing, so they are free from contamination caused by rolling oil residue. As a result of improvements, attempts have been made to manufacture milk clean sheets that omit the electrolytic cleaning process, but at present, problems remain in the cleanliness of the product surface. In order to solve this problem, the present inventors first sprayed the steel material at the final stand of the tandem rolling mill at the same time as rolling it, thereby effectively removing the surface residue of the steel sheet after rolling. Invented a cleaning agent for rolled steel materials and succeeded in establishing a technology to efficiently produce highly clean milk cleaning sheets (Japanese Patent Application Laid-open No. 100131-100131, 100131-1982, 10236-10236, 54-54-
10237 etc.). These cold-rolled steel detergents remove fine iron powder and iron oxides, which form and remain on the surface of cold-rolled steel sheets and serve as the core of contaminants, through the action of an "organic chelating agent," and at the same time remove rolling oil. It is a cleaning agent that exhibits a strong cleaning effect that is not found in conventional cleaning agents, as it can disperse and remove particles using the action of a strong "surfactant." However, if it is applied only to the final stand of a tandem rolling mill, contamination of the cleaning fluid by rolling oil will progress rapidly, or the cleaning time will be short, so the surface cleanliness will be lower than that of the electrolytic cleaning method mentioned above. The problem is that the surface cleanliness of the cold-rolled sheet after passing through the line varies greatly. If this type of cleaning agent is applied to the latter two stands, its powerful cleaning effect will remove the oil on the strip surface, and the cleaning agent will not have lubricating ability.
Rolling on the final stand becomes extremely difficult, and as a result, a large amount of iron powder is generated, which impairs the cleaning ability of the cleaning agent, leading to even worse results. The present invention has been made to solve the above problems, and is a cleaning agent that can stably produce milk-clean sheets with even higher surface cleanliness. That is, by blending an organic chelating agent, a surfactant, and an organic sulfur compound, a detergent with an excellent cleaning effect can be obtained, and the general formulas [], [],
By blending the succinic acid derivative represented by [ ] and preparing it as an aqueous solution, we created a cleaning agent composition for cold rolled steel that can obtain lubricity equivalent to rolling oil without impairing the cleaning effect. did. According to the present invention, it is possible to perform rolling using a cleaning agent in multiple stands at the rear stage of a tandem rolling machine, and the amount of iron powder generated is also reduced, resulting in stable milk clean sheets with extremely high surface cleanliness. It becomes possible to obtain it by doing so. As the chemical used in the cleaning agent of the present invention, a compound represented by the following general formula is preferably used. [A] Organic chelating agent The organic chelating agent used here removes fine iron powder and iron oxide, which are the core of contaminants generated on the surface of a cold rolled steel sheet during cold rolling, by a chelating action. The following compounds are used that are water-soluble and have a stable chelating ability with iron. 1. Oxycarboxylic acids containing at least one hydroxyl group and one carboxyl group each in the molecule. 2. Amino group and carboxyl group in the molecule,
Aminocarboxylic acids containing at least one each. 3 Sulfono group and carboxyl group in the molecule,
Phosphonocarboxylic acids each containing at least one or more phosphonocarboxylic acids. 4. Aminophosphonic acids containing at least one phosphono group and at least one amino group each in the molecule. 5 Alkali metal, ammonium, _C1 to _C4 lower amine, or up to _C6 alkanolamine salts as described in 1.2.3.4 above. At least one kind selected from the group consisting of, or a mixture of two or more kinds. [B] Surfactant The surfactant used here has the effect of effectively dispersing and emulsifying oil remaining on the surface of cold-rolled steel sheets, and is particularly non-active against mineral oil-based rolling oil. For ionic activators with HLB values of 11 to 15, and for rolling oils based on animal and vegetable oils, it is recommended to use nonionic activators with HLB values of 8 to 11 and anionic activators in combination with organic chelating agents. Demonstrate a mutual effect. Generally, cationic surfactants have poor oil dispersing ability, and amphoteric surfactants are also significantly less effective than nonionic surfactants and anionic surfactants. 1 Anionic activator that can be represented by the following general formula ○A R—SO ₃ A or R—SO ₃ H・X ○Ro R—O—SO ₃ A or R—O—SO ₃ H・X R:C ₆ ~ _C30 alkyl group, alkenyl group, _C9
An alkyl phenyl group or a diphenyl ether group having a _C12 alkyl group. _{A :} Hydrogen _, alkali metal _{or ammonium} ) n-(C ₂ H ₄ O) mH R: C ₆ to C ₃₀ alkyl group, alkenyl group, C ₉
Alkyl phenyl group, diphenyl ether group or (C ₂ H ₄ O) having ~C ₁₂ alkyl group
m′H group. n: 0~30 m: 5~50 ○Ro R: _C6 to _C22 alkyl group or alkenyl group. n+n': 0~30 m+m': 5~50 or R: _C6 to _C22 alkyl group or alkenyl group. At least one type or a mixture of two or more types selected from the group consisting of n+n'+n'': 0 to 30 m+m'+m'': 5 to 50. [C] Organic sulfur compound The organic sulfur compound used here has the effect of further improving the cleaning effect on the surface of cold rolled steel sheets by adding a small amount to a cleaning agent containing an organic chelating agent and a surfactant. , a compound that can be stably dissolved and dispersed in a cleaning solution. Based on the method of using the cleaning agent of the present invention, organic sulfur compounds that are highly volatile or generate pungent or peculiar odors cannot be used, but organic sulfur compounds of the following general formula (1) or (2) ) Organic sulfur compounds are suitable. (1) R ₁ , R ₂ : may be the same or different, each hydrogen,
C ₁ to C ₈ alkyl group, alkenyl group, alkynyl group, allyl group, alkylaryl group, aralkyl group, -(C ₂ H ₄ O) nH (where n = 1
~20) and may be condensed with each other to form an alicyclic ring or a heterocyclic ring. A: or: R ₃ , R ₄ : Has the same content as R ₁ , R ₂ or -S/B or -SH/X B: Hydrogen or alkali metal. X: _C1 - _C4 lower amine, up to _C6 alkanolamine or _C5 - _C6 saturated cyclic amine. : _C1 to _C16 alkyl group, alkenyl group, alkynyl group, allyl group, alkylaryl group or aralkyl group. (2) R: _C1 to _C18 alkyl group, alkenyl group, alkynyl group, allyl group, alkylaryl group,
An aralkyl group, a cycloalkyl group, or a heterocycle containing an N atom or an N atom or an S atom. (x): 1 to 5, however, if B is other than R, (x) = 1 (y): 0 to 5, however, if B is hydrogen,

[Formula] Or (x) = 0 for alkali metals. - (C ₂ H ₄ O) nH (n = 1 to 20), (y) =
0-1 B: Hydrogen, -(C ₂ H ₄ O) nH (n = 1-20), R (has the same content as the above R),

[Formula] or alkali metal. A mixture of at least one or two or more selected from the group consisting of: [D] Carboxylic acid The carboxylic acid used here is a compound that can be used in combination with the above-mentioned organic chelating agent, surfactant, and organic sulfur compound to maintain the lubricating effect without reducing the cleaning effect. be. The following general formula
Carboxylic acids represented by (1) and (2), and alkali metal, ammonium, C ₁ to C ₄ lower amines or C ₆ to alkanolamine salts of formula (1). (1) (2) R: _C6 to _C22 long chain aliphatic hydrocarbon group R': At least one type or a mixture of two or more selected from the group consisting of hydrogen or _C1 to _C4 lower aliphatic hydrocarbon groups . Most of the above organic chelating agents, surfactants, organic sulfur compounds, and carboxylic acids are in the form of solids or viscous pastes or waxes, making them easy to handle as cleaning agents for cold-rolled steel sheets. To do this, the cleaning agent according to the invention is prepared as an aqueous solution. The suitable blending ratio is basically 10 to 30 parts of organic chelating agent and 10 to 30 parts of surfactant.
30 parts, organic sulfur compound 0.5-10 parts, carboxylic acid 0.5
~10 parts and 20 to 80 parts of water, but if necessary, by adding a water-soluble organic solvent such as alcohol,
It is preferable to make it easier to dissolve poorly water-soluble surfactants, organic sulfur compounds, and carboxylic acids. In addition, to prevent foaming due to surfactants under actual usage conditions, silicone-based or
It is best to mix 0.1 to 5 parts of a foam suppressor such as ethylene oxide/propylene oxide block polymer, or adjust the solution to a neutral aqueous solution with a pH of 5 to 8 so as not to damage the tandem rolling mill or cold rolled steel sheet. (In this case, the agent used for neutralization is ammonia, lower amine, or the like, which does not have to remain as a residue on the surface of the cold-rolled steel sheet during annealing.) The cleaning agent of the present invention, which is prepared as a liquid preparation, is diluted 20 to 200 times with water depending on the degree of contamination of the cold-rolled steel plate to which it is applied, and then applied to multiple stands downstream of a tandem rolling mill or to the final stand. Use spray. If a cold-rolled steel sheet whose surface has been surface cleaned with the cleaning agent of the present invention requires temporary rust prevention, it is also possible to separately add a water-soluble temporary rust preventive agent to the cleaning agent of the present invention. However, in the present invention, when all or part of the organic chelating agent is a salt of a lower amine or an alkanolamine, it is usually not necessary to add a rust preventive agent. Therefore, it has sufficient temporary rust prevention effect. The present invention will be explained in detail below with reference to Examples. The organic chelating agent, surfactant, organic sulfur compound, and carboxylic acid used in the Examples are as shown in Tables 1, 2, 3, and 4, respectively. In addition, the following measuring device was used to evaluate the lubricity. Measurement of friction coefficient: Soda pendulum type oil-based friction tester Measurement of oil film strength: Soda type four-ball friction tester The test pieces used to determine the cleaning effect of cold rolled steel sheets were mineral oil-based [mark P ], animal oil (beef tallow) base [mark Q], and vegetable oil (palm oil) base [mark R] rolling oils are used to cold roll the steel plate, and the steel plate is cut into 50 x 50 mm. Example 1 As described in Table 5, an organic chelating agent, a surfactant, and an organic sulfur compound were mixed, the pH was adjusted to 7 using ammonia, and then water was added to make the total 100 parts by various rolling methods. The cleaning effect of test pieces rolled using oil was measured. Test method (1) Judgment of surface cleaning effect of cold rolled steel sheet. Test specimens prepared from cold-rolled steel plates using various rolling oils were immersed in a 5% aqueous solution of chemicals kept at a temperature of 50°C in a constant temperature bath, and the rolling oil remaining on the surface of the test specimens was removed. and the removal effect of pollutants,
After brushing in a 5% sodium orthosilicate aqueous solution in advance, the specimen was washed with water and ether, and the immersion time (seconds) required to obtain the same surface condition as a completely cleaned specimen was compared. investigate. Note that five test pieces were used for each test, and the surface condition was determined by visual judgment. The results are as listed in Table 5 (Test No. 1~
54) According to the results in Table 5, 1. When an organic chelating agent is used in combination with a nonionic surfactant and an anionic activator with an HLB value of 8.1, animal and vegetable oil-based rolling will occur regardless of the type of organic chelating agent or surfactant. To effectively remove contaminants from the surface of cold rolled steel sheets rolled by oil. Similarly, when an organic chelating agent and a nonionic activator with an HLB value of 13 are used in combination, the surface of a cold-rolled steel sheet rolled with mineral oil-based rolling oil can be effectively cleaned. 2 Add a third layer to the mixture of organic chelating agent and surfactant.
When an organic sulfur compound is used as a component, the cleaning effect is dramatically improved. Example 2 Based on the drug composition of Example 1, Test Nos. 1, 2, and No.
We mainly selected 12 and 13, mixed them with carboxylic acid that is thought to contribute to improved lubricity, and measured their friction coefficient and cleaning effect. The coefficient of friction was measured using a 2% aqueous solution at 20° C., repeated 20 times, and the average value was rounded to three decimal places. The determination of the cleaning effect was the same as in Example 1. The results are shown in Table 6. From the results in Table 6, 1. Fatty acids such as lauric acid and stearic acid significantly lower the friction coefficient of the cleaning agent, but on the contrary, they clearly inhibit the cleaning effect. 2 Dibasic acids such as sebacic acid and maleic acid, benzoic acid which is an aromatic acid, and carboxylic acids with polynuclear groups such as abietic acid hardly contribute to reducing the coefficient of friction and at the same time do not impair cleanliness. . 3 Derivatives of succinic acid, a dibasic acid, clearly lower the friction coefficient of detergents and
Compositions containing organic sulfur compounds have almost no effect on the cleaning effect. 4. The combined effect of succinic acid derivatives shows approximately the same tendency regardless of the type of organic chelating agent, surfactant, and organic sulfur compound. From the above results, it is clear that an organic chelating agent, a surfactant, an organic sulfur compound, and a succinic acid derivative must be included as essential components in the composition of a detergent for cold-rolled steel sheets that have lubricating properties. Summer. Example 3 The oil film strength of the detergent composition that showed good effects in Example 2 was measured. Test method Testing machine: Soda type four-ball friction tester Test solution concentration: 2% aqueous solution Test temperature: 30°C Number of revolutions: 200 RPM Others are the same as in Example 3. The results are shown in Table 7. From the results in Table 7, 1. By using an organic chelating agent, a surfactant, an organic sulfur compound, and dodecyl succinic acid in combination, the oil film strength can be increased to 3% of the normally used concentration of mineral oil-based rolling oil without reducing the cleaning effect. It improves to almost the same value as water emulsion. 2 Good effects are also shown when dodecylsuccinic acid and dodecenylsuccinic anhydride are used together. Example 4 In general, aqueous solutions of nonionic surfactants and anionic surfactants with an average HLB value of 9 or more exhibit high foaming properties. Foaming properties of the agent may become a problem. In such cases, silicone antifoaming agents or propylene oxide/ethylene oxide block polymers (which fall within the range of nonionic surfactants and have the effect of foam suppressing agents, although they cannot be expected to have any cleaning ability) may be used in combination. However, especially regarding the influence on cleaning effect, foam suppression effect, and influence on lubricity, we selected the blending compositions of Test Nos. 107 and 115, which were determined to be good in Example 4, and added propylene oxide and ethylene oxide block polymers, respectively. Tested in combination. Foaming test method As shown in Figure 1, put 100ml of test drug aqueous solution 2 with a concentration of 5% into a 500ml graduated cylinder 1,
The solution is kept in a constant temperature water bath 3 at 50° C., and air is blown into the bottom of the aqueous solution at a rate of 2 liters per minute from the differential user stone 5 using an air pump 4 to compare the foaming properties with and without a foam suppressor. The cleanliness and friction coefficient were measured in accordance with the test method of Example 4. Example 5 An actual machine test was carried out using the detergent composition of the present invention of Test No. 118 and the detergent of Test No. 2 composition which did not have lubricity, using a tandem rolling mill. Actual machine test conditions (1) Cleaner concentration: 2% aqueous solution (2) Spray part: Tandem rolling mill No. 4, No. 5 stand (3) Spray amount: 4000l/min (4) Spray temperature: 60℃ (5) Cold rolled steel type: Low carbon ordinary steel (6) Rolling oil used: Beef tallow base (7) Rolling oil concentration: 3% water emulsion (8) No.4, No.5 stand reduction ratio: See Table 9 (9) No. 4. No. 5 stand roll surface finish: Bright (10) Rolling speed: See Table 9 (11) Amount of test coils: 100 coils per test condition Table 9 shows the surface cleanliness of cold rolled steel sheets obtained by actual machine tests. Shown below. From the actual machine test results, (1) No rolling troubles were observed due to the use of detergent spray. (2) The cleaning agent has almost no foaming properties, and stable circulation spray processing is possible. (3) Even if the amount of rolling oil mixed in exceeded 1%, the cleaning effect was not affected. (4) Regarding the detergent without lubricity (Test No. 2 composition), when sprayed only on No. 5 stand, there is a slight effect on the rolling speed, but the oil content is lower than that of the rolled material on all stands. The amount of adhesion has been reduced to approximately 1/4, and the amount of iron adhesion has been reduced to 1/2.
Furthermore, when No. 4 and No. 5 stands were sprayed, the oil content further decreased to 1/8, but the iron content increased to 2/3. Can not. (5) A detergent with lubricating properties (Test No. 118 composition)
When spraying on No. 4 and No. 5 stands, it is possible to maintain the same rolling speed as when all stands are treated with rolling oil, and the amount of oil deposited is approximately 1/1.
8. It was confirmed that the amount of iron adhesion was significantly reduced to approximately 1/3, and it was possible to produce a Mil-Clean sheet with extremely high surface cleanliness. (6) Rolled coils after any cleaning agent treatment are exposed to the atmosphere.
Even after being left for 10 days, no rusting phenomenon was observed. (7) The cleanliness of the surface of the steel sheet after annealing was completely comparable to the cleanliness of the surface of the steel sheet annealed after electrolytic cleaning treatment, and there was no occurrence of the black stain phenomenon.

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【table】 [Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the apparatus used in the foamability test of Example 4. 1: Measuring cylinder, 2: Test drug aqueous solution, 3:
Constant temperature water tank, 4: Air pump, 5: Differential user stone.

Claims (1)

[Claims] 1. An organic chelating agent, a surfactant, an organic sulfur compound, and at least one or more carboxylic acids selected from the following general formulas [], [], []. A surface cleaning agent for cold-rolled steel sheets prepared as an aqueous solution. R: _C6 to _C22 long chain aliphatic hydrocarbon group. R': hydrogen or _C1 to _C4 lower aliphatic hydrocarbon group. [] Alkali metal, ammonium, C ₁ to C ₄ lower amine or C ₆ to alkanolamine salt of the general formula []. 2. The agent for cleaning the surface of cold-rolled steel according to claim 1, which contains a foam suppressor.