JP2000282094A - Degreasing wash water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain degreasing wash water capable of synthetically satisfying quality, economical efficiency and safety by preparing the wash water from alkaline electrolytic water and specifying the total concentrations of sodium ions and potassium ions, chloride ion concentration and pH. SOLUTION: This degreasing wash water is prepared from alkaline electrolytic water so as to provide 0.2-5 mmol/L total concentration of sodium ions and potassium ions, <=1 mmol/L of chloride ions and pH 9-12. The resultant degreasing wash water is obtained by electrolyzing water prepared by, as necessary, adding a sodium salt, a potassium salt, etc., to tap water or pure water with an electrolytic bath having ion-permeable diaphragms between anodes and cathodes, collecting water produced on the side of the cathode compartments (alkaline electrolytic water) and preparing the wash water. The resultant degreasing wash water is capable of effectively removing oils sticking to the surface of an article to be washed and suppressing the deterioration of surface properties of the article to be washed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to degreasing washing water prepared from alkaline electrolyzed water obtained by electrolysis with a diaphragm using water containing an electrolyte as a raw material.

[0002]

2. Description of the Related Art Freon 113 and 1,1,1-trichloroethane have been used in degreasing for many years because of their excellent degreasing properties and nonflammability. In recent years, the problem of depletion of the ozone layer has emerged as a matter of concern for all humankind, and the Montreal Protocol of 1987 has decided to finally stop the production and consumption of ozone-depleting substances. Production of specified CFCs and 1,1,1-trichloroethane, including CFC113, was banned at the end of 1995, and alternative CFC-free cleaning technologies have been developed, but a definitive alternative has been found. There is no present.

[0003] Alternative cleaning agents are broadly classified into aqueous, semi-aqueous and non-aqueous. For aqueous systems, alkaline cleaning agents, neutral cleaning agents,
There is an acid-based cleaning agent that is nonflammable and has little harm to the human body.
Therefore, a rinsing step, a rust prevention step, and a drying step are required, and wastewater treatment cannot be omitted, resulting in poor quality cost balance.

[0004] The semi-aqueous detergent is obtained by combining water with a flammable solvent such as hydrocarbon, glycol ether, methylpyrrolidone and the like, and adding a surfactant. It is the same as an aqueous system in that the degreasing power is somewhat weak, and there is a danger of ignition due to the inclusion of a flammable solvent, and a rinsing step and a drying step are required and wastewater treatment cannot be omitted.

[0005] Non-aqueous detergents include alcohols, hydrocarbons, and silicone solvents, all of which are flammable, are regulated by the Fire Service Law, and require measures against fire and explosion.
In the case of hydrocarbons, oily mist and odor may be generated, and exhaust measures must be taken.

[0006] On the other hand, Japanese Patent Application Laid-Open No. 9-137287 discloses a method of cleaning a processed iron product by first cleaning with an acidic electrolytic water and then with an alkaline electrolytic water. In this method, it is an essential condition to combine washing with acidic electrolyzed water and alkaline electrolyzed water in this order, and at least two washings with two types of washing water are indispensable. This is particularly disadvantageous in terms of economic efficiency.

Further, Japanese Patent Application Laid-Open No. Hei 10-192860 discloses that
In metal washing with electrolytic alkaline water, there is disclosed a method of keeping the residual chlorine concentration in the electrolytic alkaline water at a low level so as not to rust the metal after the washing. Residual chlorine is a form of active oxygen and is a substance or ion characterized by a strong oxidizing action, and is not the only absolute ion harmful to metal rusting.

[0008] As described above, none of the conventional alternative techniques has comprehensively satisfied the quality, economy, and safety.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and it is an object of the present invention to provide a degreasing water which satisfies quality, economy and safety comprehensively. Aim.

[0010]

A first aspect of the present invention is degreasing washing water prepared from alkaline electrolyzed water, wherein the concentration of sodium ion + potassium ion in the washing water is high.
0.2 mmol / L or more, 5 mmol / L or less, chloride ion concentration 1 mmol / L or less, pH 9
It is intended to provide degreasing washing water characterized by being at least 12 or less.

According to the first aspect of the present invention, by using alkaline electrolyzed water having a specific range of sodium ion concentration + potassium ion concentration and chloride ion concentration and having a specific range of pH, it is possible to clean the article to be cleaned. The oil adhering to the surface can be effectively removed and removed, and deterioration of the surface properties of the article to be cleaned can be suppressed.

A second aspect of the present invention is degreasing washing water prepared from alkaline electrolyzed water, wherein the calcium ion concentration in the washing water is 0.5 mmol / L or more, and
The present invention provides degreasing washing water characterized by having a mmol / L or less, a chloride ion concentration of 2 mmol / L or less, and a pH of 9 or more and 12 or less.

According to the second aspect of the present invention, the oil separated from the surface of the article to be cleaned is emulsified and dispersed in water to form a W / O type micelle and is prevented from re-adhering to the surface of the article to be cleaned. The effect of removing and removing oil can be enhanced. Also,
By forming a thin film on the article surface after washing with a polymer compound formed by the reaction between calcium ions and oil, it is possible to prevent permeation of moisture in the atmosphere and prevent deterioration of the article surface properties. .

A third aspect of the present invention is a degreasing washing water prepared from alkaline electrolyzed water, wherein the concentration of sodium ion + potassium ion in the washing water is 0.2 mmol / L or more and 5 mmol / L or less. The present invention provides a degreasing washing water characterized in that the calcium ion concentration is 0.5 mmol / L or more and 10 mmol / L or less, the chloride ion concentration is 2 mmol / L or less, and the pH is 9 or more and 12 or less.

According to the third aspect of the present invention, a more effective degreasing and cleaning is achieved by combining the oil removing effect of trace sodium ions and trace potassium ions, the effect of capturing and stabilizing the oil component of calcium ions, and the effect of preventing surface property deterioration. Water can be provided.

A fourth aspect of the present invention is a degreasing washing water prepared from alkaline electrolyzed water, wherein the concentration of sodium ion + potassium ion in the washing water is 0.2 mmol / liter or more and 5 mmol / liter. Below, calcium ion concentration 0.5 mmol / l or more, 10
Mmol / l or less, (sodium ion concentration + potassium ion concentration) / (sodium ion concentration + potassium ion concentration + calcium ion concentration) in molar ratio
The present invention provides degreasing washing water characterized by having a chloride ion concentration of 0.2 to 0.8, a chloride ion concentration of 2 mmol / L or less, and a pH of 9 to 12 or less.

According to the fourth aspect of the present invention, the concentrations of sodium ions + potassium ions and calcium ions in the washing water are specified in the same manner as in the above invention, and (sodium ion concentration + potassium ion concentration) / (sodium ion concentration + By setting the molar concentration ratio of (potassium ion concentration + calcium ion concentration) to 0.2 or more and 0.8 or less, the oil separating effect, the oil trapping / stabilizing effect, and the prevention of surface property deterioration described in the first to third inventions. The effect is exhibited comprehensively.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The degreasing washing water of the present invention may be used in tap water or pure water, if necessary, with sodium salts, potassium salts such as sodium chloride, sodium hydrogen carbonate and potassium chloride;
Further, water to which a calcium salt such as calcium chloride is added is electrolyzed using an electrolytic cell having an ion-permeable diaphragm between the anode and the cathode, and water (alkaline electrolyzed water) generated on the cathode chamber side is produced. It can be obtained by collecting and preparing. As this electrolysis apparatus, for example, JP-A-9-137
287 etc. can be adopted.
In this case, in the present invention, by appropriately selecting the concentration of each salt dissolved in water to be subjected to electrolysis, electrolysis conditions, and the like,
Contains a predetermined type of ion at a predetermined concentration and a predetermined p
An alkaline electrolyzed water having H is produced.

The degreasing cleaning water according to the first aspect of the present invention is degreasing cleaning water prepared from alkaline electrolyzed water, and has a sodium ion concentration + potassium ion concentration in the cleaning water.
0.2 mmol / L or more, 5 mmol / L or less, chloride ion concentration 1 mmol / L or less, pH 9
It is assumed to be 12 or less.

As a result of intensive studies, the present inventors have found that when performing degreasing cleaning using alkaline electrolyzed water, trace amounts of sodium ions and potassium ions must be removed to remove oil adhering to the surface of the article to be cleaned. It was found to be effective and both ions acted equivalently. In this case, the lower limit of the concentration of the sodium ion and the concentration of the potassium ion that effectively function for oil separation is 0.2 mmol / liter.

On the other hand, if sodium ions or potassium ions are excessively contained in the washing water, the surface properties of the washed article are adversely affected, and if the article is metal, rusting is promoted. The upper limit of sodium ion + potassium ion for preventing this adverse effect from developing is 5 mmol / liter.

The presence of chloride ions has a significant adverse effect on the surface properties of the article. Even when the conditions described above are satisfied, if the chloride ion concentration exceeds 1 mmol / l, the surface properties tend to deteriorate after degreasing and washing, so that the chloride ion concentration is suppressed to 1 mmol / l or less. There is a need.

The pH of the washing water is pH 9 or more as a condition for making the above-mentioned oil separating effect of trace sodium ions and potassium ions effective, and pH 12 as a condition for not adversely affecting the surface properties of the article to be washed. The following is required.

The second degreasing washing water of the present invention is a degreasing washing water prepared from alkaline electrolyzed water, wherein the calcium ion concentration in the washing water is 0.5 mmol / L or more and 10 mmol / L or less. , The chloride ion concentration is 2 mmol / l or less, and the pH is 9 or more and 12 or less.

When degreasing is performed using alkaline electrolyzed water, the oil removed from the surface of the article to be cleaned is emulsified and dispersed in water.
Partly forms W / O type micelles. This W / O type micelle has a high adhesive force, and when it re-adheres to the surface of the article to be cleaned, it is extremely difficult to completely remove it again.

The present inventors have conducted intensive studies in order to prevent the formation and reattachment of the W / O micelles. As a result, the alkaline electrolyzed water contains calcium ions of 0.5 mmol / l or more, and thus the washing is performed. It has been found that the formation of W / O micelles with high adhesion to the surface of the object can be prevented. This is because a three-dimensional network structure of a polymer such as calcium soap is formed by the reaction between calcium ions and oil, and the oil is trapped and stabilized therein.

Calcium ions have an oil-peeling promoting effect similar to that of sodium ions. In this case, the lower limit of the concentration of calcium ions that effectively functions is 0.5 mmol / liter.

On the other hand, the high molecular compound containing calcium is rich in water repellency, and by forming a thin film on the surface of the article after washing, the penetration of moisture in the air is prevented. To prevent deterioration.

When the concentration of calcium ions exceeds 10 mmol / L, the formation of this polymer network is inhibited, and it becomes difficult to exert the effects of capturing oil and preventing deterioration of surface properties. It must be kept below liters.

Even when the conditions described above are satisfied, if the chlorine ion concentration exceeds 2 mmol / liter, the surface properties of the article after degreasing and washing tend to deteriorate, so that the chlorine ion concentration is 2 mmol / L. / Liter or less.

The pH of the electrolyzed water is set at 9 or more as a condition for making the above-mentioned effect of separating and trapping and stabilizing the oil content of calcium ions effective, so that it does not adversely affect the surface properties of the article to be cleaned. PH12 as the condition
The following is required.

The third degreasing cleaning water of the present invention is degreasing cleaning water prepared from alkaline electrolyzed water, wherein the concentration of sodium ion + potassium ion in the cleaning water is 0.2%.
More than mmol / l, less than 5 mmol / l,
Calcium ion concentration of 0.5 mmol / L or more, 1
The concentration is 0 mmol / l or less, the chloride ion concentration is 2 mmol / l or less, and the pH is 9 or more and 12 or less.

The degreasing water according to the third aspect of the present invention provides a better degreasing and cleaning effect by combining the effect of removing trace amounts of sodium ions and trace amounts of potassium from oil, the effect of trapping and stabilizing oil of calcium ions, and the effect of preventing deterioration of surface properties. Thus, the effect of preventing deterioration of the surface properties after cleaning can be obtained.

In order to exhibit the effect of the third invention, for the same reason as described for the first and second inventions, the concentration of sodium ion + potassium ion, the concentration of calcium ion, the concentration of calcium ion and the pH It is necessary to control the upper and lower limits of the above and the upper limit of the chloride ion concentration within the above specified ranges.

The fourth degreasing cleaning water of the present invention is degreasing cleaning water prepared from alkaline electrolyzed water, wherein the concentration of sodium ion + potassium ion in the cleaning water is 0.2%.
More than mmol / l, less than 5 mmol / l,
Calcium ion concentration of 0.5 mmol / L or more, 1
0 mmol / L or less, (Sodium ion concentration +
The molar ratio of potassium ion concentration / (sodium ion concentration + potassium ion concentration + calcium ion concentration) is 0.2 or more and 0.8 or less, the chloride ion concentration is 2 mmol / l or less, and the pH is 9 or more and 12 or less.

In the washing water according to the fourth aspect, the molar concentration ratio of (sodium ion concentration + potassium ion concentration) / (sodium ion concentration + potassium ion concentration + calcium ion concentration) is set to 0.2 or more and 0.8 or less. The oil peeling effect, the oil trapping / stabilizing effect, and the surface property deterioration preventing effect are comprehensively exhibited.

In order to exhibit the effect of the fourth invention, for the same reason as described in the first, second and third aspects of the present invention, the concentration of sodium ion + potassium ion, calcium ion It is necessary to adjust the upper and lower limits of the concentration and the pH and the upper limit of the chloride ion concentration to the above specified ranges.

The object to be cleaned which is suitable for cleaning with the degreasing cleaning water of the present invention includes, for example, metals such as iron, steel, copper and brass, alloys, plastics and ceramics. The cleaning method is not particularly limited. For example, a method of immersing the article to be cleaned in degreased cleaning water and applying ultrasonic waves to clean the article, or a method of shower-cleaning the degreased cleaning water toward the article to be cleaned is adopted. Is done.

[0039]

Example 1 Water obtained by adding 0.15 to 3.5 mM of sodium chloride to pure water (furthermore, about 0.3 mM of potassium chloride in the case of Example 1-3) was added to an anode described in JP-A-9-137287. By electrolysis at a current density of 0.3 to 1 A / dm ² and a voltage of 25 to 60 V by an electrolysis apparatus having a membrane through which ions permeate between the cathode and the cathode, the alkaline electrolyzed water generated on the cathode chamber side is collected. 1
Each of the degreasing washing waters having the ion concentration and the pH shown in Table 3 was obtained.

Using each of the obtained washing waters, a test for degreasing and washing was performed by the method described below. The object to be cleaned is an electrogalvanized steel sheet (30 × 50 × 1 mm), which is immersed in press working oil (manufactured by Daido Chemical Co., Ltd., Dydraw HBCC-1) and sufficiently oiled on the front and back surfaces. Immerse in 475 mL of washing water in a beaker and apply ultrasonic waves at a frequency of 27.5 kHz.
Washing was performed for minutes. After the washing was completed, the ink was immersed in a 25% aqueous ink solution, immersed for 1 minute, pulled up and air-dried, and the degree of degreasing was determined by observing the situation where the surface to be cleaned was covered with the aqueous ink solution.

After the washing was completed, the specimen which had been naturally dried without being immersed in the aqueous ink solution was subjected to a wet test in which the specimen was kept in an atmosphere of a temperature of 50 ° C. and a humidity of 98% for 96 hours. Was observed to determine the rust-preventive ability of the specimen after degreasing and washing. Table 1 shows the chemical components of the degreasing washing water, and the results of the washing test and the wetting test.

[0042]

[Table 1]

The cleaning method using the cleaning water according to each of the claims of the present invention is not limited to the above-mentioned materials and methods, and is also excellent in general methods such as spray cleaning for articles to be cleaned. It has the effect.

Example 2 Degreasing washing water having the ion concentration and pH shown in Table 2 was obtained in the same manner as in Example 1. However, in Example 2-2, water obtained by adding 0.15 mM of sodium hydrogen carbonate to pure water was electrolyzed. Using the degreasing water obtained in Examples 2-1 and 2-2 obtained in this manner, using a nozzle having a discharge pressure of 1.5 kgf / cm ² G, for an electrogalvanized steel sheet coated with oil in the same manner as in Example 1. A spray cleaning for 30 seconds was performed, and a cleaning test and a wet test were performed. Table 2 shows the chemical components of the degreasing cleaning water, and the results of the cleaning test and the wet test.

[0045]

[Table 2]

Further, using the washing water of Examples 2-1 and 2-2,
The result of performing the same spray cleaning on the plastic thin plate was also good, and it was confirmed that the surface was sufficiently degreased and that the surface properties were not adversely affected.

Further, when the ion residue after washing was measured for the samples of Examples 2-1 and 2-2 in Table 2, 0 to 180 mg
/ m ² , which is extremely low as compared with the conventional cleaning method.

As described above, the cleaning water of the present invention is characterized in that the amount of ions contained is very small as compared with the conventional water-based cleaning agent. This means that the washing water has a very small environmental load and, at the same time, the amount of ion residue remaining in the washed article is small.

Example 3 Water obtained by adding 0.5 to 6.5 mM of calcium chloride to pure water was electrolyzed in the same manner as in Example 1, and alkaline electrolyzed water generated on the cathode chamber side was collected. The degreasing washing water having the ion concentration and the pH shown in Table 1 was obtained.

Using the obtained washing water, a degreasing washing test and a wetting test of the metal were carried out in the same manner as in Example 1. Table 3 shows the chemical components of the washing water, and the results of the washing test and the wetting test.

[0051]

[Table 3]

Example 4 Water obtained by adding sodium chloride and / or calcium chloride (potassium chloride in Examples 4-3 and Comparative Examples 4-2 and 4-3 to tap water or pure water) was used. Electrolysis was performed in the same manner as in Example 1, and the alkaline electrolyzed water generated on the cathode chamber side was collected and collected.
By preparing, degreasing washing water having an ion concentration and a pH shown in Table 4 was obtained.

Using the obtained washing water, a degreasing washing test and a wet test of the metal were carried out in the same manner as in Example 1. Table 4 shows the chemical components of the washing water, and the results of the washing test and the wetting test.

[0054]

[Table 4]

Example 5 Water obtained by adding sodium chloride and / or calcium chloride (potassium chloride in Examples 5-3 and Comparative Examples 5-2 and 5-3 to tap water or pure water) was used. Electrolysis was performed in the same manner as in Example 1, and the alkaline electrolyzed water generated on the cathode chamber side was collected and collected.
By preparing, degreasing washing water having an ion concentration and a pH shown in Table 5 was obtained.

Using the obtained washing water, a degreasing washing test and a wetting test of the metal were conducted in the same manner as in Example 1. Table 5 shows the chemical components of the washing water, and the results of the washing test and the wetting test.

[0057]

[Table 5]

In Examples 5-1 to 5-3, even if the cleaning time was reduced to 30 seconds instead of 1 minute, the results of the cleaning test and the wet test did not change. Good results were obtained.

All the degreasing tests shown in Tables 1 to 5 were carried out at room temperature. However, if the temperature of the cleaning water was raised to 60 ° C. on a trial basis, the cleaning time required to obtain the same cleaning effect was obtained. It was found to be reduced by almost half or less. Therefore, raising the temperature of the washing water is effective for further promoting the effects of the present invention.

[0060]

As described above, according to the present invention,
In performing degreasing cleaning using alkaline electrolyzed water, a trace amount of alkali metal ions and alkaline earth metal ions are present in the cleaning water in a well-balanced manner, and the chloride ion concentration is kept low, and the pH is controlled in a necessary range. By
Not only can the article be efficiently degreased, but also an excellent effect of preventing surface property deterioration of the washed article can be provided.

Further, in the present invention, it is sufficient to wash once with one kind of washing water, so that pre-washing and post-washing are unnecessary, and it is possible to provide washing water which is extremely excellent in economical efficiency. it can.

Further, the washing water contains only a trace amount of ions, does not contain organic solvents or inorganic salts which are harmful to the environment, and it is possible to keep the ion residue on the article surface after washing low. It is possible to provide extremely excellent cleaning water in terms of the environment.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Jinichi Ito 1-2-1 Nishiwaseda, Shinjuku-ku, Tokyo Inside Zipcom Corporation (72) Inventor Masakazu Nakamura 1-6 Kojimachi, Chiyoda-ku, Tokyo Nippon Steel Corporation Inside the Technical Information Center (72) Inventor Hiroo Matsuda 1-6 Kojimachi, Chiyoda-ku, Tokyo Nippon Steel Technical Information Center (72) Insider Naoko Isobe 1-6 Kojimachi, Chiyoda-ku, Tokyo Nippon Steel Technical Information Center (72) Inventor Masao Sakashita 1-15-20- 504 Ikuta, Tama-ku, Kawasaki City, Kanagawa Prefecture (1) Takahashi Metals Co., Ltd. (30) Inventor Kiyoji Nishimura 30 Hosoe, Biwa-cho, Higashi-Asai-gun, Shiga Prefecture (72) Inventor Hiroyasu Noriyasu Hirokawa No. 30, Biwa-cho, Higashi-Asai-gun, Shiga Prefecture Takahashi Kin F-term (reference) 4H003 BA12 DA05 DA09 DA12 DB02 ED02 FA01 FA06 FA15 FA28 4K053 PA02 PA06 QA04 RA07 RA21 RA25 SA04 SA06 SA18 TA12

Claims (4)

[Claims] 1. A degreasing washing water prepared from alkaline electrolyzed water, wherein the concentration of sodium ions in the washing water is +
Potassium ion concentration of 0.2 mmol / L or more, 5 mmol / L or less, chloride ion concentration of 1 mmol / L
Degreasing washing water characterized by having a liter or less and a pH of 9 or more and 12 or less. 2. Degreasing washing water prepared from alkaline electrolyzed water, wherein the calcium ion concentration in the washing water is 2.
0.5 mmol / L or more, 10 mmol / L or less, chloride ion concentration 2 mmol / L or less, pH 9
Degreasing cleaning water characterized by being at least 12 and at most 12. 3. Degreasing cleaning water prepared from alkaline electrolyzed water, wherein the concentration of sodium ions in the cleaning water is +
Potassium ion concentration of 0.2 mmol / L or more, 5 mmol / L or less, calcium ion concentration of 0.5 mmol / L or more, 10 mmol / L or less, chloride ion concentration of 2 mmol / L or less, pH of 9 to 12
Degreasing cleaning water characterized by the following. 4. A degreasing cleaning water prepared from alkaline electrolyzed water, wherein the concentration of sodium ions in the cleaning water is +
Potassium ion concentration of 0.2 mmol / L or more, 5 mmol / L or less, calcium ion concentration of 0.5 mmol / L or more, 10 mmol / L or less;
(Sodium ion concentration + potassium ion concentration) / (sodium ion concentration + potassium ion concentration + calcium ion concentration) in molar ratio of 0.2 or more and 0.8 or less, chloride ion concentration of 2 mmol / l or less, pH of 9 or more and 12 or less Degreasing cleaning water, characterized in that there is.