KR100723214B1 - Degreasing agent for rolling fluid having low saponification value with excellent deforming and cleaning - Google Patents

Abstract

Low saponification relates to degreasing agents which are excellent in degreasing (cleaning) and anti-foaming properties for rolled oil or rust preventive oil. A first solution in which sodium hydroxide and builders are mixed in a 20: 1.5 to 6.5 weight ratio; And 5.0-20.0 wt% of a nonionic surfactant of Formula 1 based on the total weight of the second solution, RO- (EO) _M (PO) _N H (wherein R is a C6-C18 alkyl group and EO is ethylene oxide Group, PO is a propylene oxide group, M and N are each not 0, and the M + N value is an integer from 5 to 20.), sodium naphthalenesulfonate, 1,2-benzylisotriazole and mixtures thereof A second solution consisting of 1.2 to 6.5% by weight of a selected complex additive, 0.3 to 1.5% by weight of a chelating agent selected from methylphosphonic acid, diphosphonic acid, and mixtures thereof, and a residual solvent; and a first solution and a second solution. A low saponification agent mixed in a 1: 0.02-0.45 weight ratio is provided for the degreaser. The degreasing agent of the present invention is excellent in degreasing (cleaning) and anti-foaming properties for the electrical steel sheet treated with low kneading oil and is environmentally friendly.

Degreaser, antifoaming, detergency, electrical steel sheet

Description

Degreasing Agent for Rolling Fluid Having Low Saponification Value with Excellent Deforming and Cleaning}

1 is a graph showing the degreasing property of rolling oil for an electrical steel sheet when the degreasing agent according to the present invention is used;

Figure 2 is a graph showing the degreasing properties of the rolling oil for the electrical steel sheet material when using a conventional degreasing agent.

The present invention relates to a degreasing agent used to remove the rolling oil remaining on the steel sheet after rolling using low rolling oil, and more specifically, the low degreasing agent remaining on the surface of the electrical steel sheet after the rolling process. Cleaning and anti-foaming properties, as well as an environmentally friendly degreasing agent.

In general, rolled oil or rust preventive oil is applied to the surface of the electrical steel sheet after the rolling process in the form of a film. Before the introduction of such electrical steel sheet into the annealing furnace, a degreasing process is required to remove the rolled oil or rust preventive oil. At this time, when the degreasing of the rolled oil or the rust preventive oil is not sufficiently performed, problems such as graphite precipitation, contamination in the furnace, adverse effects on chemical conversion treatment, degradation of plating adhesion, and the like, may cause problems such as deterioration of the quality of the electrical steel sheet.

In general, the factors affecting the degreasing property of the rolling oil remaining on the surface of the steel sheet after the rolling process are the properties of the rolling oil used and the rolling conditions. High saponification value (saponification value) of the rolling oil properties are advantageous for degreasing, while low saponification value is disadvantageous for degreasing. That is, in general, when the saponification value is high as 200-300, such as rolling oil for cold rolled steel sheet, it is advantageous to design a degreasing agent excellent in performance. However, in the case of electrical steel sheet, it is difficult to design a degreasing agent having excellent degreasing property (cleanability) because rolling oil having a saponification value of about 130 is lower than that of a high saponification agent for cold rolled steel sheet having a saponification value of 170 to 210.

In addition, when the degreasing property according to the difference in the number of rolling passes according to the thickness is examined, as the number of rolling passes increases, the possibility of burning of the rolling oil increases, which greatly affects the degreasing property.

In the case of degreasing the electrical steel sheet rolled with the rolling oil in such a way that the general high degreasing is degreasing agent for rolling oil removal, the degreasing becomes poor and the above problems occur. Development is required.

In order to solve this problem, various degreasing agents have been developed. For example, Japanese Patent Laid-Open No. 3-227400 discloses a rosin-based soldering flux detergent composed of a nonionic surfactant polyoxyethylene alkyl ether and a glycol ether compound. have. Japanese Patent Laid-Open No. H11-302686 discloses a granular nonionic detergent composition composed of a nonionic surfactant, a chelate, a clay mineral and, if necessary, an organic / inorganic builder. On the other hand, Korean Patent No. 292287 discloses a one-component composition for degreasing-pickling-rusting which can perform degreasing, pickling and rust prevention in a single process when pickling ferrous or non-ferrous structures, and the patent is used for degreasing agents. As the surfactant component, polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether and the like are disclosed.

As described above, nonyl phenolic compounds are generally used as the nonionic surfactant added to the degreasing agent. However, nonyl phenolic compounds are not only used to cause environmental pollution due to residual phenol, but are also harmful to humans, and therefore their use is regulated. Therefore, there is a need for the development of a degreasing agent using a nonionic surfactant that can replace it.

Accordingly, it is an object of the present invention to provide a degreasing agent that is excellent in degreasing (cleaning) and antifoaming properties for rolled oil and rust preventive oil.

It is another object of the present invention to provide an environment-friendly low saponification rolled oil and rust preventive oil degreasing agent that does not generate harmful components to the environment and human body.

According to the invention,

Minimum selected from the group consisting of sodium hydroxide, sodium gluconate, sodium metasilicate, sodium orthosilicate, metapotassium silicate, sodium pyrophosphate, tetrasodium phosphate, tripolysodium phosphate, hexamethodium phosphate, potassium hydroxide and potassium carbonate A first solution in which a builder is mixed in a 20: 1.5 to 6.5 weight ratio; And

 5.0 to 20.0 wt% of a nonionic surfactant of Formula 1 based on the total weight of the second solution,

[Formula 1]

RO- (EO) _M (PO) _N H

(Wherein R is a C6-C18 alkyl group, EO is an ethylene oxide group, PO is a propylene oxide group, M and N are not each 0, and the M + N value is an integer of 5-20.)

1.2 to 6.5% by weight of a compound additive selected from sodium naphthalenesulfonate, 1,2-benzylisotriazole and mixtures thereof,

It consists of a second solution consisting of 0.3 to 1.5% by weight of the chelating agent selected from methylphosphonic acid, diphosphonic acid and mixtures thereof and the balance solvent,

The first solution and the second solution are provided with a degreasing agent for the low saponified rolled oil mixed in a 1: 0.02-0.45 weight ratio.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

Generally, degreasing treatment is performed to remove the rolled oil or rust preventive oil remaining on the electrical steel sheet after the rolling process, and in order to increase the degreasing (cleaning) and anti-foaming properties of the degreasing agent used at this time, builders, surfactants, Additives and chelating agents are mixed. The degreasing agent of the present invention not only exhibits excellent degreasing (cleaning) and anti-foaming properties for rolling oils, in particular low saponification, for rolling oils by using specific builders, nonionic surfactants, complex additives and chelating agents, but also is harmful to humans and the environment. It is eco-friendly and does not generate substances.

In addition, the degreasing agent using a conventional nonionic surfactant should be added to the defoaming agent to generate a lot of bubbles separately, but the degreasing agent of the present invention using a specific nonionic surfactant to be described later is less foaming to separate the antifoaming agent No need to use

In particular, the degreasing agent of the present invention is a low degreasing agent used in electrical steel sheet that is excellent in degreasing property for rolling oil. Although the said low saponification rolled oil is not limited to this, it means the rolling oil whose saponification value is 170-210, for example.

The degreasing agent of the present invention comprises a first solution comprising sodium hydroxide and a builder and a second solution comprising a surfactant, a complex additive, and a chelating agent.

The first solution is composed of sodium hydroxide, builders and the residual solvent, wherein the sodium hydroxide and builders is preferably mixed in a 20: 1.5 to 6.5 weight ratio.

Sodium hydroxide degreasing as a subject.

Builders are selected from the group consisting of sodium gluconate, sodium metasilicate, sodium orthosilicate, metapotassium silicate, sodium pyrophosphate, tetrasodium phosphate, tripolysodium phosphate, hexametadium phosphate, potassium hydroxide and potassium carbonate Some kind can be used. These builders can be used alone or in mixtures of various kinds. Sodium gluconate is the most preferred builder. The builder acts as a stable component of the degreasing agent.

The sodium hydroxide and the builder is mixed in a 20: 1.5 to 6.5 weight ratio. When the mixing ratio of the builders to 20 parts by weight of sodium hydroxide is less than 1.5 parts by weight, the dispersion effect and the recontamination prevention effect is reduced, if there is more than 6.5 parts by weight there is a problem that precipitation occurs.

In addition to the sodium hydroxide and the builder, the first solution includes water as a solvent, and the amount of water is not particularly limited, and may be used in an amount generally applicable in the art in consideration of the concentration of sodium hydroxide in the final degreasing agent and the application as the degreasing agent. have.

The second solution consists of a nonionic surfactant, a complex additive, a chelating agent and a residual solvent.

As the nonionic surfactant, a compound having Formula 1 may be used.

[Formula 1]

RO- (EO) _M (PO) _N H

(Wherein R is an alkyl group of C6-C18, EO is an ethylene oxide group, PO is a propylene oxide group, M and N are not each 0, and M + N values are integers of 5 to 20).

 If the M + N value is less than 5, it is not preferable in terms of degreasing effect, and if it exceeds 20, it is not preferable in terms of degreasing and defoaming. The nonionic surfactant constituting the second solution in the degreasing agent of the present invention may be prepared from C6 to C18 fatty acid alcohols.

The amount of the nonionic surfactant added to the second solution of the degreasing agent is preferably 5.0 to 20.0% by weight based on the total weight of the second solution. If it is less than 5.0% by weight, the cleaning and dispersion penetrating effect is weak, and if it exceeds 20.0% by weight, the stability of the solution is deteriorated and excessive bubbles are generated.

Polyoxyethylene may be further added to the second solution as a separate surfactant. The polyoxyethylene may be added to the second solution in an amount of 0-80 parts by weight, preferably up to 60 parts by weight, more preferably up to 40 parts by weight, per 100 parts by weight of the nonionic surfactant of Formula 1. If polyoxyethylene is used in an amount exceeding 80 parts by weight, the amount of foaming is increased and it is uneconomical.

The co-additive constituting the second solution is formulated for solubility, dispersibility and stabilization of the degreasing agent and is selected from sodium naphthalenesulfonate, 1,2-benzylisotriazole and mixtures thereof. The complex additive is added to the second solution at 1.2-6.5% by weight, preferably 2.5-6.0% by weight, based on the total weight of the second solution. When the addition amount of the complex additive to the second solution is less than 1.2% by weight, the dispersion and rust preventing effects are insufficient, and when it exceeds 6.5% by weight, an excessive amount of bubbles is generated.

An organic chelating agent is also added to the second solution of the degreasing agent according to the invention.

The organic chelating agent in the second solution is used as a metal ion blocking agent which forms a complex with metal ions and blocks the function of the metal ions. In addition, the chelating agent is a compound containing two or more atoms having a non-covalent electron pair to form a coordination bond with the metal ion to form a stabilized chelate ring, resulting in increased stability of the degreasing agent.

As the organic chelating agent, methylphosphonic acid, diphosphonic acid and mixtures thereof can be used. The organic chelating agent may be added to the second solution at 0.3-1.5% by weight, preferably 0.4-1.2% by weight based on the total weight of the second solution. If it is less than 0.3% by weight, the chelate effect is insignificant. If it exceeds 1.5% by weight, corrosion occurs due to an excessive amount of Cl, an impurity present in the organic chelate.

It is preferable that the degreasing agent of this invention mixes a 1st solution and a 2nd solution by 1: 0.02-0.45 weight ratio. If the mixing ratio is out of the bubble generation suppression effect is reduced.

The degreasing agent in which the first solution and the second solution are mixed at a weight ratio of 1: 0.02-0.45 is applied in the field, and it is preferable to use the solvent by diluting it to 1.0 to 3.5% by weight based on sodium hydroxide concentration.

If the concentration of sodium hydroxide in the diluted degreasing agent applied in the field is less than 1.0% by weight, it is not preferable in terms of degreasing effect due to the lack of degreasing agent, and in the case of more than 3.5% by weight, it is not preferable in terms of cost.

Water may be used as a solvent used to dilute the solvent and the degreasing agent constituting the first solution and the second solution.

In the degreasing agent of the present invention, a conventional phenolic surfactant is not used, and unlike the conventional one, a nonionic surfactant made of an environmentally friendly series is used to prevent environmental pollution and to clean the steel sheet treated with rolling oil. Excellent defoaming and degreasing (cleaning). The degreasing agent of this invention shows the degreasing | defatting property of rolling oil, especially low saponification with respect to rolling oil. The low saponification value rolling oil is, for example, a rolling oil having a saponification value of 170-210.

Hereinafter, the present invention will be described in detail through examples. However, the following examples are provided to help the understanding of the present invention, and the present invention is not limited thereto.

Example 1

 (Degreasing agent manufacture of invention example 1)

A first solution was prepared by dissolving 20 g of sodium hydroxide and 4 g of sodium gluconate in 100 g of water. Separately, 15.4 g of polyoxyethylene propylene, 4.8 g of sodium naphthalene sulfonate, and 0.4 g of (1-hydroxyethylidene) diphosphonic acid sodium salt were dissolved in 88 ml of water to prepare a second solution. The degreasing solution was prepared by mixing 100 g of the first solution and 15 g of the second solution.

(Manufacture of the degreasing agent of the invention example 2)

The degreasing agent of Inventive Example 2 was prepared by the same method as the degreasing agent of Inventive Example 1, except that 6.2 g of polyoxyethylene was added to the second solution in the degreasing agent of Inventive Example 1.

Example 2

In this embodiment, the degreasing agent of Inventive Example 1 and Inventive Example 2 prepared in Example 1 was compared with a commercially available conventional product (product name: Strip Cleaner, manufactured by Samyeop Chemical Co., Ltd.). The degreasing agents of Inventive Examples 1 and 2 were diluted with water so that the NaOH concentration was 2.5% by weight.

The degreasing treatment was carried out in accordance with the process of (alkali degreasing) → (washing) → (electrolytic degreasing) → (washing) under the same conditions as the degreasing treatment generally performed in steel mills.

Using the degreasing agent of Inventive Examples 1 and 2 and the degreasing agent of the conventional example prepared in Example 1, the electrical steel specimens treated with the rolling oil having a saponification value of 190 were alkali degreased. The specimens were immersed in each degreasing agent at 80 ° C. for 5 seconds for alkali degreasing and then washed with water spray. Thereafter, electrolytic degreasing as described later, water was further sprayed and washed with water to perform a degreasing step. This degreasing step was repeated four times using the degreasing agent of Inventive Example 1, two times using the degreasing agent of Invention Example 2 and two times using the degreasing agent of the prior art.

In the case of electrolytic degreasing, the DC power supply of the rectifier was connected to the electrode and the specimen of the electrolytic degreasing device to enable the energization. At this time, the positive electrode was applied to the specimen and the positive electrode was applied to the counter electrorod through the entire experimental procedure, and hydrogen gas was generated on the surface of the specimen, and oxygen gas was generated on the opposite electrode.

Degreasing property after the degreasing process, the amount of the rolling oil present in each specimen was evaluated by measuring the amount of organic carbon with a surface organic carbon analyzer shown in Figures 1 and 2 below. 2, ③, ⑤, and ⑥ in FIG. 1 show a case where the degreasing agent of Inventive Example 1 is treated, and ① and ④ indicate a case where the degreasing agent of Inventive Example 2 is treated. 2 shows a case of treating with a degreasing agent of the conventional example.

In the case of degreasing using the degreasing agent of Inventive Examples 1 and 2, as shown in FIG. 1, the residual surface carbon content in the electrical steel sheet is 3.14 to 5.13 mg / m ^2, but in the case of degreasing using the degreasing agent of the prior art, The residual surface carbon content in the steel sheet was 20.3 to 35.6 mg / m ² . From this, it was found that the degreasing property (detergency) of the degreasing agent according to the invention example with respect to the rolling oil is remarkably improved compared with the conventional degreasing agent.

Example  3

This Example evaluates the degreasing agent of the degreasing agent of Inventive Example 2 and the degreasing agent in the conventional example.

In order to evaluate the defoaming of the degreasing agent, the suppression and breaking time were measured at room temperature and 85 ° C., respectively. In evaluating the defoaming property of the degreasing solution, in order to simulate that the degreasing solution used in the field contains the rolled oil liberated from the steel sheet, 1 wt% of a rolling oil having a saponification value of about 190 was added to evaluate the defoaming property.

Evaluation of the properties of the degreasing and defoamability of the degreasing solution is shown in Table 1 by measuring the amount of foam by the KSM 2709 method (Ross-Miles).

 TABLE 1

Inventive Example 2 Conventional example Anti-foaming (degreaser with 1% rolled oil) Suppression Breakable Suppression Breakable Temperature Room temperature No bubble - 5 minutes 36 seconds 85 ℃ 6 minutes 5 sec 52 seconds 38 minute, 50 seconds

As shown in Table 1, the degreasing agent of Inventive Example 2 did not generate bubbles at room temperature, without foaming at 85 ° C. for 6 minutes, and was blistered within 5 seconds to show excellent defoaming properties. On the other hand, the degreasing agent of the prior art not only generate | occur | produces a bubble after 5 minutes at normal temperature, but it took a long time to rupture.

By using the degreasing agent of the present invention, low saponification present in the electrical steel sheet after the rolling process is effectively degreased (washed). The degreasing agent of the present invention also exhibits excellent antifoaming properties and is environmentally friendly.

Claims (7)

Minimum selected from the group consisting of sodium hydroxide, sodium gluconate, sodium metasilicate, sodium orthosilicate, metapotassium silicate, sodium pyrophosphate, tetrasodium phosphate, tripolysodium phosphate, hexamethodium phosphate, potassium hydroxide and potassium carbonate A first solution in which a builder is mixed in a 20: 1.5 to 6.5 weight ratio; And  5.0 to 20.0 wt% of a nonionic surfactant of Formula 1 based on the total weight of the second solution, [Formula 1] RO- (EO) _M (PO) _N H (Wherein R is an alkyl group of C6-C18, EO is an ethylene oxide group, PO is a propylene oxide group, M and N are not each 0, and the M + N value is an integer of 5 to 20). 1.2 to 6.5% by weight of a compound additive selected from sodium naphthalenesulfonate, 1,2-benzylisotriazole and mixtures thereof, 0.3 to 1.5% by weight of a chelating agent selected from methylphosphonic acid, diphosphonic acid and mixtures thereof and the residual solvent The second solution consisting of; A degreasing agent for low saponification rolling oil, in which the first solution and the second solution are mixed in a weight ratio of 1: 0.02-1: 0.45. The degreasing agent according to claim 1, wherein polyoxyethylene is added up to 80 parts by weight per 100 parts by weight of the nonionic surfactant of Formula 1 to the second solution. 3. The degreasing agent according to claim 2, wherein the polyoxyethylene is added up to 40 parts by weight. The degreasing agent of claim 1, wherein the builder is sodium gluconate. The degreasing agent according to claim 1, wherein the degreasing agent is used by diluting the sodium hydroxide to 1.0-3.5 wt%. The degreasing agent according to claim 1, wherein the degreasing agent for electric steel sheet is used for degreasing rolled oil. The degreasing agent according to claim 1 or 6, wherein the low saponification value rolling oil is a rolling oil having a saponification value of 170 to 210.

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