JPH0448877B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a cleaning agent for steel materials, and more particularly to a cleaning agent used for spray cleaning treatment at the final stand of a tandem rolling mill during cold rolling. [Prior Art] Conventionally, in the cold rolling process, rolling oil based on oils and fats and rolling oil based on mineral oil are generally used depending on the desired thickness of the final steel plate. That is, since oils and fats have high lubricity, they are used for rolling thin plates that require high pressure, and mineral oils have poor lubrication performance, so they are used for rolling relatively thick steel plates that do not require high pressure. Rolling oil based on this mineral oil is characterized by a lower residual carbon content during annealing in the post-process than oils and fats, and therefore steel sheets treated with rolling oil that do not have very strict requirements for sheet surface cleaning are It is possible to skip the next step, the alkaline electrolytic cleaning line, and proceed directly to annealing. However, processing heat, pressure, and
Also, the current situation is that the mineral oil-based rolling oil deteriorates due to the components of the iron powder, and the residual carbon content during annealing increases, resulting in unsatisfactory rolling. In recent years, in order to improve these points, high-pressure jetting of hot water and furthermore, a detergent spray called detergent has been used in tandem final stands. In other words, these methods are attempts to effectively remove rolling oil, iron powder, and their reaction products in the rolling process immediately after rolling. This is intended to prevent oil stains that occur during annealing by reducing the amount as much as possible. [Problems to be Solved by the Invention] The present invention aims to provide a cleaning agent composition that has improved cleaning ability and extended durability of the cleaning agent sprayed on the final stand of these tandem rolling mills. It is. In other words, a cleaning agent called detergent is usually sprayed on the final stand of rolling tandems, but due to work safety issues such as the impact of the cleaning fluid mist on the human body, and corrosivity to equipment, this cleaning method is not recommended. There are restrictions on the drugs used in the drug. and,
At present, detergents are neutral detergents based on surfactants.
However, unlike detergents that use alkaline agents or organic solvents, such detergents do not have the ability to saponify or solubilize contaminant oils such as rolling oil, so they do not disperse the contaminant oil in the cleaning solution. Stability depends solely on the emulsifying and dispersing action of the surfactant in the cleaning solution. Therefore, there are disadvantages in that cleaning performance decreases as the oil content increases due to the influence of mixed oil such as rolling oil, and that a relatively low amount of mixed oil causes the problem of oil re-deposition and shortens the life of the cleaning agent. In addition, in order to improve the problem of re-deposition and reduced cleaning performance, using a large amount of surfactant can cause foaming when the cleaning solution is recycled, so careful attention must be paid to operational management. . [Means for Solving the Problems] The present inventors have discovered that they are capable of uniformly dispersing mixed oil in a cleaning liquid, have excellent degreasing power without being affected by mixed oil, and that the liquid properties As a result of intensive research to obtain a cleaning agent that is neutral, we found that a combination of a specific nitrogen-containing compound and an anionic surfactant and/or a nonionic surfactant has excellent cleaning power. It was discovered that a neutral metal cleaning composition can be obtained, and the present invention was completed. That is, the present invention provides (A) a specific anionic surfactant and/or nonionic surfactant;
(B) A metal cleaning composition characterized in that it contains compounds of the following general formulas ○I to ○C and is formulated as an aqueous solution with a pH of 5 to 9 and does not contain an organic chelating agent. ○he R-NH ₂・CH ₃ COOH (wherein R, R ₁ , R ₂ and R ₃ represent a C ₁ to _{C 20} alkyl group or alkenyl group or a C ₈ to C ₁₂ alkyl phenyl group, (n is an integer of 0 to 30, m is an integer of 1 to 40, l is an integer of 1 to 40, and o is an integer of 1 to 10, respectively) Specific compounds of ○A to ○ used in the present invention Examples are as follows. That is, as compound ○a, polyoxyethylene caprylamine, polyoxyethylene laurylamine, polyoxyethylene myristylamine, polyoxyethylene oleylamine, polyoxyethylene palmitylamine, polyoxyethylene stearylamine, etc. are used as the compound ○b. Examples of the compounds include polyoxyethylene caprylamide, polyoxyethylene laurylamide, polyoxyethylene myristylamide, polyoxyethylene palmitylamide, polyoxyethylene oleylamide, polyoxyethylene stearylamide, etc. Polyoxyethylene capryl propylene diamine, polyoxyethylene lauryl propylene diamine, polyoxyethylene myristyl propylene diamine, polyoxyethylene palmityl propylene diamine, polyoxyethylene oleyl propylene diamine, polyoxyethylene stearyl propylene diamine, etc. Can be mentioned. In addition, compounds in ○2 include trimethylamine oxide, triethylamine oxide, tributylamine oxide, trihexylamine oxide, trioctylamine oxide, etc., and compounds in ○e include tetramethyl ethylene diamine oxide, tetraethyl ethylene diamine oxide, etc. Diamine oxide, tetrabutyl ethylene diamine oxide, tetrahexyl ethylene diamine oxide, etc. Compounds in ○ include laurylamine acetate, palmitylamine acetate, dodecylamine acetate, stearylamine acetate, oleylamine acetate, etc. It will be done. These compounds ○I to ○F can be blended into the metal cleaning composition of the present invention singly or in combination of two or more, and the blending amount is 0.1 to 10% by weight (hereinafter simply referred to as "%"). ), particularly preferably from 0.5 to 5%. Further, there are no particular restrictions on the anionic surfactant and nonionic surfactant to be blended into the metal cleaning composition of the present invention, but examples thereof include the following. Anionic surfactant The following are preferably used as the anionic surfactant. ○A R ₄ SO ₃ X ○B R ₄ -O-SO ₃ X ○C R ₄ COOX In the formula, _R4 : an alkylphenyl group having a _C6 to _C22 alkyl group, an alkenyl group, or a _C8 to _C12 alkyl group. X: Alkali metal, ammonium, _C1 - _C6 lower amine Nonionic surfactant Preferably, a nonionic surfactant represented by the following general formula is used. ○I R ₅ O(-C ₂ H ₄ O) _o --H ○Ro R ₅ O(-C ₂ H ₄ O) _o --(-C ₃ H ₆ O) _o --H ○Ha R ₅ COO (-CH ₂ CH ₂ O) _o --H In the formula, n: 3 to 50 m: 1 to 40 R ₅ : C ₆ to C ₃₀ alkyl group or alkenyl group, or an alkyl phenyl group having a C ₈ to C ₁₂ alkyl group R ₆ : C ₆ to C ₁₈ alkyl groups These surfactants are blended singly or in combination of two or more, and the blending amount is 0.1 to 10% in the composition.
It is particularly preferably 1 to 5%. The metal cleaning composition of the present invention is prepared by blending the essential components in a conventional manner. and,
This composition itself exhibits very high cleaning power, so
Usually does not require various builders. However, if an inorganic builder such as soda carbonate, mirabilite, sodium pyrophosphate, or sodium tripolyphosphate is used in combination, the detergency will further increase, so it is preferable to use a builder in combination when the stain is severe. The thus obtained metal cleaning composition of the present invention is preferably used in a range of 0.01 to 3%.
The pH of this composition is preferably 5-9. [Actions and effects of the present invention] Degreasing power is significantly improved by using compounds ○I to ○ of the present invention in combination with an anionic surfactant, a nonionic surfactant, or a mixture of both surfactants. This makes it possible to uniformly emulsify and disperse the oil and iron powder mixed in by washing. Furthermore, since it is not corrosive to steel materials, steel with good sheet surface properties can be obtained. [Example] Next, the present invention will be explained in more detail with reference to Examples. Example 1 A nonionic surfactant or an anionic surfactant was mixed with the compounds indicated by ○I to ○ listed in Table 1 in various proportions, and this drug was added to water to a concentration of 0.2%. The cleaning properties of cold-rolled steel sheets were compared using diluted cleaning solutions. (Test method) Using a spray device as shown in Figure-1,
Cleaning solution diluted to 0.2wt% (temperature: adjusted to 80℃)
Steel plate (100 x 100 mm) taken immediately after cold rolling
It was then cleaned by spraying for 3 seconds at a pressure of 1.0 Kg/cm ² . Ten test pieces were used for each test piece, and the amount of iron powder and oil on the surface before and after cleaning were determined to evaluate the cleanability. The amount of oil was determined by extracting the oil on the steel surface before cleaning with ether, and the amount of rolling oil adhered after cleaning was determined, and the cleaning rate was determined from the following formula. Cleaning rate = Amount of adhesion before cleaning - Amount of adhesion after cleaning / Amount of adhesion before cleaning x 100 In addition, the iron powder removal rate is determined by wiping off the iron powder on the board surface with absorbent cotton and removing it with H ₂ SO ₄ H ₂ O ₂ , the amount of iron powder was determined by atomic absorption spectrometry, and the removal rate was determined. Iron powder removal rate = amount of iron powder before cleaning - amount of iron powder after cleaning / amount of iron powder before cleaning x 100 The steel used here was rolled using mineral oil-based rolling oil. (Results) The results of the combination with non-ionic surfactants are
Table 2 shows the results of combinations with anionic surfactants. In addition, "POE(8)" in Table 1 means a polyoxyethylene group to which eight oxyethylene groups are added.

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【table】

[Table] From these results, it can be seen that the removal rate of rolling oil or iron powder adhering to the steel plate surface is very low when using nonionic surfactants and anionic surfactants alone, but It has become clear that the detergency is significantly improved when used in combination with other compounds. It has also become clear that when these are used in combination, the cleaning performance varies depending on the mixing ratio with the surfactant, and it is better when the compounding amount of the compounds shown in ◯I to ◯ is relatively low.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a spray device used in Examples.

Claims (1)

_[ Claims] 1 ( _A ) General formula _{R 4 SO 3} C ₆ lower amine) and/or anionic surfactant represented by the general formula R ₅ O(-C ₂ H ₄ O) _o --H (wherein R ₅ is a C ₆ to _{C 30} It represents an alkyl group, an alkenyl group, or an alkyl phenyl group having a _C8 to _C12 alkyl group, and n is 3 to 50
0.1 to 10% by weight of a nonionic surfactant represented by (In the formula, R represents a C ₁ to C ₂₀ alkyl group or alkenyl group, or a C ₈ to _{C 12} alkyl phenyl group, n is an integer of 0 to 30, and m is an integer of 1 to 40
(where l is an integer of 1 to 40) 0.1 to 10% by weight of a compound represented by Composition.