KR20190116864A - Degreasing agent - Google Patents

Abstract

A degreasing agent is disclosed. According to the present disclosure, the degreasing agent consists of 5 to 50 wt% of alkaline agents alone or more than two types, 0.001 to 5.0 wt% of nonionic surfactants alone or more than two types, 0.5 to 10.0 wt% of anionic surfactant alone or more than two types, 0.1 to 15.0 wt% of sodium gluconate as a solubilizer, 0.01 to 5.0 wt% of chelating agents alone or more than two types, water, etc.

Description

Degreasing agent

Degreasing agent is disclosed. In more detail, after applying rolling oil in a cold rolling mill of a steel company, various oil components and contaminants on the surface of the material passed through the cold rolling process are removed, or before electroplating or hot dip plating is performed in the plating mill. In an alkaline degreasing process for the purpose of removing rust preventive oil applied to a surface, a degreasing agent capable of complete degreasing even at a normal temperature or higher at which no steam is used is disclosed.

In general, in order to produce a cold rolled finished product in a cold rolling mill, oil components such as rolling oil coated on the surface of a steel sheet during a cold rolling process are first cleaned with an alkaline degreasing agent in a degreasing process, which is a pretreatment process. At this time, the degreasing process is largely divided into four stages: immersion degreasing section, electrolytic degreasing section, water washing section, and drying section. Among these sections, the degreasing degreasing section and electrolytic degreasing section, which are closely related to degreasing, are washed with alkaline solution. . At this time, the rolling oil, oil, and organics on the surface of the strip are washed as the soap is generated through the saponification reaction with the alkaline substance which is the main component of the degreasing agent. In this case, the cleaning power is greatly affected by the temperature of the degreasing agent. It shows excellent detergency at a temperature of 80 ° C. or higher at which saponification reaction occurs smoothly.

Korean Laid-Open Patent Publication No. 2003-0054383 shows the difference of the degreasing rate by temperature through experiments.

Korean Patent Publication No. 2006-0072352 and Korean Patent Publication No. 2003-0054383 describe in detail parts of surfactants and other additives that enable degreasing even at low temperatures of 55 to 65 ° C. The temperature at which steam is required.

Korean Patent Publication No. 10-1070127 provides a new degreasing agent that can be used at room temperature of 20 ~ 40 ℃, but when applied to the production site has caused a lot of difficulties in separately managing the concentration of the degreasing component and additives.

The cleaning principle of alkaline degreasing agent uses a method of converting and removing the oil component into soap by mutual saponification reaction between the alkaline agent which is the main component of the detergent in the degreasing section and the oil component attached to the surface of the cold rolled steel sheet. The high temperature degreasing agent to raise the temperature to more than 80 ℃ that saponification reaction well occurs, or the low temperature degreasing agent to be degreased at a temperature of 60 ℃ by adding a special surfactant was used a lot of energy by a large amount of steam supply, this problem Korean Patent Laid-Open Publication No. 2012-0098536, filed by the present inventors to solve the problem, provides a new room temperature degreasing agent in which a degreasing component and an additive are mixed, as well as to overcome the phenomenon of lowering degreasing power due to a drop in working temperature. The purpose is to cross the heat generated in the electrolytic degreasing section with the tank in the deposition degreasing section and The degreasing method is proposed to perform degreasing without the use of steam by making it reusable.However, this leads to the rapid decontamination of the degreasing agent in the electrolytic degreasing tank, which should be kept clean, resulting in degreasing defects and degreasing-related defects. New problems have arisen that the replacement time of the room temperature degreasing agent is accelerated.

The present invention has been made to solve the problems of the conventional degreasing agent and the degreasing process as described above, at 20 to 40 ℃ room temperature conditions without a separate steam supply without circulating the degreasing agent in the electrolytic degreasing tank and the deposition degreasing tank It is to provide a new degreasing agent capable of perfect degreasing.

In general, in the process of using an alkaline degreasing agent, it has been considered impossible to degrease while maintaining the temperature of the degreasing agent at room temperature of 20-40 degreeC. Under this temperature condition, the saponification reaction, which is the basic principle of alkaline degreasing, does not occur at all, which is impossible without introducing a new degreasing principle.

Therefore, the alkaline degreasing agent of the present invention is contaminated from the surface of the steel sheet by using the wet, emulsifying and dispersing action of well-combined nonionic and anionic surfactants, rather than saponification, of oil components that are contaminants contaminated on the surface of the steel sheet. By separating the substances and enhancing the performance of the solubilizers, the separated oil components can be quickly dissolved completely into the degreasing agent to prevent secondary contamination, without having to circulate the degreasing agent in the electrolytic degreasing tank and the deposition degreasing tank. Perfect degreasing was possible.

Therefore, in order to provide a new degreasing agent that has remarkably compensated for the problem of contamination of the degreasing agent due to mutual circulation between the degreasing tanks and the various defects resulting from the inefficient use of energy when applying the high temperature degreasing agent or the low temperature degreasing agent. There is this.

 The present invention is provided with a degreasing agent of a new composition, characterized in that the degreasing agent exhibits excellent cleaning power and energy saving effect.

 According to one embodiment of the present invention, by adding, mixing and diluting in a range of 0.5 to 30% by weight in water in a tank of a steel plant degreasing line to clean the surface of the steel sheet at room temperature conditions of 20 to 40 ℃, the configuration As a component, 5 to 50 weight% of alkali agents are single or 2 types or more, 0.001 to 5.0 weight% of single or 2 types or nonionic surfactants, 0.5-10.0 weight% of solubilizing agents or two or more types, and anionic surfactant is solubilized A degreasing agent applicable at room temperature is provided, which comprises 0.1 to 15.0% by weight of zero sodium gluconate, 0.01 to 5.0% by weight of chelating agents alone or two or more, and other water.

The degreasing agent according to the present invention separates contaminants from the surface of the steel sheet by the wetting, emulsifying and dispersing action of a well-combined nonionic and anionic surfactant, and then the oil components separated by the action of solubilizers are rapidly removed. It is completely dissolved in the degreasing solution to solve various defects caused by the deterioration of degreasing power due to insufficient saponification reaction at the time of the temperature drop of the existing alkaline degreasing agent and the floating of the upper part such as rolling oil and other organic substances due to the emulsion instability. It helps to improve the environment due to energy savings.

In addition, the degreasing agent according to the present invention is mixed with each other by circulating the degreasing agent of the electrolytic degreasing tank that the conventional room temperature degreasing agent should be managed cleanly with the degreasing agent of the highly contaminated degreasing tank, the contamination of the degreasing agent in the electrolytic degreasing tank proceeds quickly. This provides a new degreasing agent containing a special anionic surfactant to solve the problem of degreasing and degreasing-related defects, which is excellent at room temperature without the mutual circulation of the degreasing agent in the deposition degreasing tank and the electrolytic degreasing tank by the action of components. By showing the degreasing force, there is an effect that can fundamentally solve various defects caused by the upper layer floating, such as rolling oil, organic matter, etc. due to the degreasing force deterioration and emulsion instability.

1 is a plan view of a degreasing process according to the present invention.
2 is a view showing a result of the degreasing force according to the present invention.

 Hereinafter, with reference to the accompanying drawings, a preferred embodiment for the degreasing effect of the degreasing agent that can be applied without mutual circulation of the degreasing solution between the immersion degreasing tank and electrolytic degreasing tank in the degreasing process at room temperature of 20 to 40 ℃ according to the present invention in detail do.

The present invention is based on alkali agents such as sodium hydroxide, potassium hydroxide, sodium silicate and the like, and as a fine preparation, a mixture of polyoxyethylene decyl ether, polyoxyethylene lauryl ether, ethylene oxide and propylene oxide block copolymer nonionic surfactant, Provides a new degreasing composition containing an anionic surfactant to prevent degreasing of the anode grid in the electrolytic degreasing tank, sodium gluconate for solubilization, chelating agent to prevent deterioration of detergency and defects caused by metal ions The present invention relates to an alkaline room temperature degreasing agent that exhibits excellent degreasing force at room temperature without mutual circulation of the degreasing liquid in the immersion degreasing tank (1) and the electrolytic degreasing tank (2).

 Degreasing agent according to an embodiment of the present invention, the alkali agent, such as sodium hydroxide, potassium hydroxide, sodium oligosilicate, sodium metasilicate, and so on, 5 to 50% by weight of a single or two or more types of alkali, non-ionic surfactant as a fine aid 0.001 to 5.0% by weight of oxyethylene decyl ether, polyoxyethylene lauryl ether and ethylene oxide and propylene oxide block copolymers alone or two or more, anionic surfactant to prevent degreasing of the anode grid in the electrolytic degreasing tank 0.5 to 10.0% by weight of single or two or more organic phosphates such as higher fatty acid soap, alkyl sulfonate, alkyl ester, alkyl benzene sulfonate, alpha olefin sulfonate, polyoxy ethylene alkylphenyl etherinic acid and phosphate ester, Sodium gluconate 0.1 to 15.0% by weight solubilizer, EDTA, NTA, HEDTA, ethylenediamine alone or It is characterized by consisting of two or more 0.01 to 5.0% by weight and other water and maximizes the cleaning power of the alkaline degreasing process even under room temperature conditions.

In constructing the degreasing agent which concerns on the Example of this invention, the reason which limited content of the said composition as mentioned above is as follows.

In the case of alkaline agents, in general, in the degreasing line, the degreasing agent is mixed with water to dilute the alkalinity to 1 to 5% by weight. Therefore, when the concentration of the alkali agent in the degreasing agent is less than 5% by weight, a very large amount of degreasing agent is added. There is a problem of economic deterioration and excessive transportation cost, and if it is more than 50% by weight, it is difficult to purchase raw materials because the concentration of the popularly produced alkali agent is 10-50%, and various surfactants contained in the degreasing agent due to the strong alkalinity This is because they cause a fatal problem in that they are broken and separated and layer separation occurs.

In the case of the nonionic surfactant as a detergent, when the content is less than 0.001%, the concentration is too low to expect the desired cleaning power. When the content is more than 5.0%, the stability is poor and problems such as layer separation and floating may occur. It is preferable to limit the amount to 0.001 to 5.0% by weight.

In the case of anionic surfactant, less than 0.5 wt% of the anionic surfactant may cause degreasing force on the positive electrode grid side of the electrolytic degreasing section, and when it exceeds 10 wt%, there is a problem in cost efficiency due to excessive input. It may be less competitive. Therefore, it is preferable to contain anionic surfactant within 0.5 to 10.0 weight%.

Sodigluconate used as a solubilizer has a problem that the concentration is too low when the content is less than 0.1% by weight, so the cleaning power is lowered. When it exceeds 15% by weight, the stability of the surfactant is poor, resulting in problems such as layer separation and floating. Since 0.1 to 15.0% by weight is preferably added.

In the case of the chelating agent, the degreasing power and sludge formation and foreign matters caused by the hardness components and metal ions contained in the degreasing agent are suppressed at the source and the oxidation discoloration of the surface of the steel sheet is prevented during the degreasing process. However, when the content is 0.01% by weight or less, various defects such as sludge generation, foreign matter, and rusting by hardness components and metal ions cannot be prevented. When the content is 5.0% by weight or more, the wettability of the caustic soda solution is inhibited. Since it is preferable to add 0.01 to 5.0% by weight.

Referring to the configuration described above with reference to the degreasing method of the present invention.

First, the room temperature degreasing additive of the present invention removes the rolling oil component and iron remaining on the surface of the cold rolled strip when 0.1 to 5.0% is added to the existing high temperature degreasing agent or low temperature degreasing agent. That is, sodium laureth sulfate, which has a wet and penetrating effect, penetrates into the contaminants attached to the strip surface to improve wettability of the caustic soda solution, thereby promoting emulsification, thereby improving degreasing power. Ammonium lauryl sulfate and polyoxyethylene lauryl sulfate, which osmotic, emulsify, and disperse the surface tension of the degreasing agent, are adsorbed at the interface between the solid and the liquid to reduce the interfacial energy, thereby inherent thermodynamic anxiety between the solid and the liquid. It decreases the degree, and increases the ζ-potential in the ion dissociative solution to prevent the coagulation by the increase of the electrostatic repulsion between dispersed particles. In addition, it is adsorbed by the solid dispersion particles to form a solvation layer around the particles to act to prevent the dispersed particles to aggregate.

Sodium oleate is present between the grid and the strip surface of the electrolytic degreasing section in the electrolytic degreasing section to emulsify solubilization of the rolling oil and organics. In addition, sodium stearate and sodium palmitate in the components of the room temperature degreasing agent are emulsified to disperse one liquid into fine particles in another liquid which is not mixed with them. Potassium hydroxide and the like are solubilized to increase solubility in water such as hydrocarbons, fatty acids, and metal soaps, which are poorly soluble in water. The solubilization is achieved by dispersing poorly soluble materials in the particles formed by the room temperature degreasing agent to lower the free energy between the particles to form a stable solution. According to the saponification reaction, by changing the components of the strip surface rolling oil composed of the lipophilic ring into the component having the hydrophilic ring which is easy to dissolve in water, the rolling oil component remaining on the surface of the strip is dissolved in the water mixed with the solution to remove the rolling oil on the surface. It will work to achieve cleanliness.

 Hereinafter, the effect of the new room temperature degreasing agent according to the present invention will be described.

Comparative Example 1

The degreasing performance measured while circulating the degreasing agent in the deposition degreasing tank 1 and the electrolytic degreasing tank 2 of the degreasing step shown in FIG. The change in the degreasing force was measured based on the whiteness, and the results are shown in Table 1.

No. Blank Degreaser circulation Degreaser Acyclic 50 ℃ 40 ℃ 30 ℃ 50 ℃ 40 ℃ 30 ℃ Whiteness (%) 93.1 91.5 90.3 89.5 90.1 86.3 79.7 91.1 89.9 87.9 89.1 85.8 79.9 90.9 90.3 89.4 88.8 97.3 80.1

Comparative Example 2

After the conventional room temperature degreasing agent is added to the degreasing process, the degreasing force change of the degreasing dehydration tank 1 and the electrolytic degreasing tank 2 of the degreasing process shown in FIG. And the results are shown in Table 2. As a result of the measurement, as shown in Table 2, the existing room temperature degreasing agent drastically lowered the degreasing power as time passed, as well as various degreasing defects and defects due to the degreasing power decontamination and degreasing agent contamination. It was confirmed that the degreasing agent in the electrolytic degreasing tank (2), which should be cleanly managed, was rapidly contaminated by mixing with the degreasing agent of the highly contaminated degreasing tank (1) by circulating the degreasing agent of the electrolytic degreasing tank (2) with each other. .

No. Blank Degreasing power (35 ℃) over time with the existing room temperature degreasing agent 12 hours 24 hours 48 hours 72 hours 96 hours Whiteness (%) 93.1 92.1 89.1 85.5 81.3 78.7 91.2 90.2 86.1 80.9 79.5 91.5 89.9 85.8 81.5 79.2

Example 1

After the new room temperature degreasing agent according to the present invention is introduced into the degreasing step, the degreasing power of the deposition degreasing tank 1 and the electrolytic degreasing tank 2 of the degreasing step shown in FIG. The change was measured based on whiteness and the results are shown in Table 3.

No. Blank Degreasing power (35 ℃) over time with the existing room temperature degreasing agent 12 hours 24 hours 48 hours 72 hours 96 hours Whiteness (%) 93.1 92.1 91.9 91.5 91.3 90.7 91.2 90.8 91.1 90.9 89.6 91.5 91.9 90.8 89.5 89.2

As a result of the measurement, as shown in Table 3, the new room temperature degreasing agent according to the present invention does not allow the existing room temperature degreasing agent to circulate the degreasing agent of the deposition degreasing tank 1 and the electrolytic degreasing tank 2 of the degreasing step shown in FIG. When it is used without the degreasing power, the degreasing power is lowered, and thus, satisfactory degreasing power can be expected. However, even when the degreasing agent 1 and the electrolytic degreasing tank 2 are inter-circulated, the degreasing agent exhibits a very good degreasing power. In addition, although the conventional degreasing agent deteriorates rapidly with time, various degreasing-related defects have occurred, but the degreasing agent according to the present invention mutually circulates the degreasing agent between the deposition degreasing tank (1) and the electrolytic degreasing tank (2). It has been shown that the degreasing agent in the electrolytic degreasing tank 2 is managed cleanly by blocking the various defects.

1: immersion degreasing tank 2: electrolytic degreasing tank
3: room temperature degreasing agent tank 4: immersion degreasing tank circulation tank
5: electrolytic degreasing tank circulation tank

Claims (6)

Degreasing agent that shows excellent cleaning power and energy saving effect at room temperature of 20-40 ℃ when added, mixed and diluted in water in the steel plant degreasing line in the range of 0.5-30% by weight. The method of claim 1,
The degreasing agent is 5 to 50% by weight alone or two or more alkaline agents, 0.001 to 5.0% by weight or two or more nonionic surfactants, 0.5 to 10.0% by weight or solubilizing anionic surfactants alone or two or more. A degreasing agent applicable at room temperature, characterized in that it comprises 0.1 to 15.0% by weight of zero sodium gluconate, 0.01 to 5.0% by weight of chelating agents alone or two or more, and other water. The method of claim 2,
The said alkaline agent is a degreasing agent consisting of single or 2 types or more among sodium hydroxide, potassium hydroxide, an sodium osilicate, and a sodium metasilicate. The method of claim 2,
The nonionic surfactant is a degreasing agent, characterized in that the polyoxyethylene decyl ether, polyoxyethylene lauryl ether, ethylene oxide propylene oxide block copolymers are used alone or in combination of two or more. The method of claim 2,
The anionic surfactant may be used alone or in combination of two or more organic phosphates such as higher fatty acid soap, alkyl sulfonate, alkyl ester ether alkyl benzene sulfonate, alpha olefin sulfonate, polyoxy ethylene alkylphenyl etherinic acid and phosphate ester. Degreasing agent, characterized in that. The method of claim 2,
The chelating agent is a degreasing agent, characterized in that the use of EDTA, NTA, HEDTA, ethylenediamine alone or in combination of two or more.

Images