JP2002350016A - Method for making ice of electrolytic water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for making ice of electrolytic water in which the function of electrolytic water can be prevented from lowering by staying components of fast decomposition rate, existing in a dissolution liquid after dissolution, for a long time. SOLUTION: Electrolytic water is placed under cooling conditions of -40 deg.C or below and frozen under that cooling conditions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing electrolyzed water ice from electrolyzed water. More specifically, the present invention relates to a method for producing electrolyzed water ice capable of suppressing a decrease in the function of electrolyzed water during freezing.

[0002] In the present invention, percentages are by weight unless otherwise specified, and ppm means mg / kg. In the present invention, the “electrolyzed water” refers to water having a bactericidal action obtained by electrolyzing water containing chlorine ions and having chlorine gas dissolved therein.

[0003]

2. Description of the Related Art In recent years, it has been known that electrolyzed water obtained by electrolysis of various solutions has a bactericidal effect, and it is urgent to establish an application technology of such electrolyzed water (Kyoko Shiba). Authors, Handbook of Strong Electrolysis Water, Medical Information Company, 1995
Year).

[0004] Further, a technique of freezing such electrolyzed water and using it as electrolyzed water ice is also known, and such electrolyzed water ice can utilize its cooling effect as well as its bactericidal effect. Used for

Regarding the electrolyzed water as a raw material of such electrolyzed water ice, the conventional electrolyzed water is disclosed in, for example,
No. 80293 (hereinafter referred to as conventional electrolyzed water 1). In this technique, water to which sodium chloride is added is passed through an electrolytic cell with a diaphragm, which is electrolyzed to obtain strongly acidic water generated on the cathode side as electrolytic water. Is not less than 1.5 and not more than 3.2, and is said to have a higher bactericidal effect than a simple low pH solution.

[0006] Electrolyzed water produced by the technique disclosed in Japanese Patent No. 2627100 (hereinafter referred to as "conventionally electrolyzed water 2") is a mixture of water to which sodium chloride is added and water to which hydrochloric acid is added. This is obtained by electrolysis in a non-diaphragm electrolytic cell, and the water to which sodium chloride is added is an indispensable additive for increasing the electrolysis efficiency at the time of electrolysis.

The present inventors have previously found electrolytic water having almost neutral pH without adding sodium chloride, and a method for producing the same, and applied for a patent (Japanese Patent Application Laid-Open No. 10-128).
No. 336. Hereinafter, this electrolyzed water is referred to as recommended electrolyzed water. ).

[0008] Each of these electrolyzed waters has a higher sterilizing effect even at a low chlorine concentration than sterilized water prepared by dissolving sodium hypochlorite in water. It is said to be preferable in that it is not necessary to perform fine density adjustment each time it is used.

On the other hand, when such electrolyzed water is frozen to obtain electrolyzed water ice, the ice generally starts to freeze from pure water in the aqueous solution, and the impurities finally freeze because the ice finally freezes. It takes a long time to make perfect ice. For this reason, components such as hypochlorous acid in the electrolytic water have a high decomposition rate, and are easily decomposed during the freezing operation.

Therefore, even if electrolytic water ice is produced,
Conventionally, there has been a problem that sufficient hypochlorous acid does not stay in the completed electrolyzed water ice, and that the obtained electrolyzed water ice cannot have sufficient effects such as sterilization.

[0011] Thus, since hypochlorous acid is an unstable component having a high decomposition rate in electrolytic water, a technique for retaining hypochlorous acid during ice making has been developed. For example, JP-A-6-285361 discloses a technique for keeping hypochlorous acid for a long period of time by confining hypochlorous acid in ice (hereinafter, referred to as a conventional technique).

According to this prior art, a container is filled with an aqueous solution in which an unstable component or the like dissolved in water and which has a high decomposition rate or a volatile component such as a volatile component is dissolved and stored in a sealed state. It is characterized in that the container is cooled from the outer peripheral side to freeze the aqueous solution.

[0013]

However, in the prior art, since the electrolyzed water ice itself is substantially sealed in a packaging container, it lacks the convenience as ice and sterilizes hypochlorous acid. The technology did not reach the technical concept of making full use of power, and the technology did not make full use of the physical properties of ice.

In view of the above-mentioned problems of the prior art, the present inventors have intensively studied a method for producing electrolyzed water ice capable of sufficiently maintaining a sterilizing function. The present inventors have found that the degree of residual chlorine changes, and completed the present invention.

An object of the present invention is to provide a method for freezing electrolyzed water.
An object of the present invention is to provide a method for producing electrolyzed water ice, which hardly deactivates components having a high decomposition rate, such as hypochlorous acid, which are present in the electrolyzed water and can maintain the effects specific to the electrolyzed water.

[0016]

According to the present invention, there is provided a method for producing electrolyzed water, comprising placing electrolyzed water under cooling conditions of -40 ° C. or lower and freezing under said cooling conditions. In this case, the electrolyzed water is an electrolyzed water having a sodium ion concentration of 200 ppm or less and a pH in a range of 4.5 to 6.8, and the electrolyzed water is substantially free of sodium chloride. In a preferred embodiment, the electrolyzed water is prepared by adding hydrochloric acid, passing the water to which the hydrochloric acid is added through a non-diaphragm electrolytic cell, electrolyzing, and diluting with water.

[0017]

Next, the present invention will be described specifically. In the present invention, the electrolyzed water is kept under a cooling condition of -40C or lower. In this case, the cooling condition means a condition for removing the heat of the electrolyzed water, and any means, medium, and the like for removing the heat may be used.

For example, if electrolyzed water is stored in a container and the stored container is placed in a freezer at -40 ° C. or lower, the air around the container serves as a medium to cool the electrolyzed water. If such a container is immersed in brine of -40 ° C or lower, the brine serves as a medium to cool the electrolyzed water.

The present invention is characterized in that the electrolyzed water is frozen under the cooling condition of -40 ° C. or less. By freezing under such cooling conditions, chlorine in the electrolyzed water is less likely to be deactivated and can remain.

The electrolyzed water used in the present invention is preferably a recommended electrolyzed water. Such recommended electrolyzed water has a sodium ion concentration of 20 which is a general water quality standard.
One feature is that it consists of electrolyzed water of 0 ppm or less, more preferably 50 ppm or less.

Conventional electrolyzed water (eg, conventionally electrolyzed water 1 or 2) is obtained by electrolyzing water, but it has been common sense to add sodium chloride to increase electrolysis efficiency. However, in the present invention, it is preferable to use recommended electrolyzed water having a sodium ion concentration of 200 ppm or less. This recommended electrolyzed water has a pH value of 4.
Another characteristic is that it is near neutrality of 5 to 6.8.

If such recommended electrolyzed water is used in the method for producing electrolyzed water ice of the present invention, it is possible to obtain ice which is less likely to corrode metals as in the conventional electrolyzed water 1 or 2. In addition, since such recommended electrolyzed water is electrolyzed water substantially containing no sodium chloride, even if it is evaporated after use, no salt is precipitated.

In this case, the recommended electrolyzed water is desirably produced by the following procedure. That is, first, hydrochloric acid is added to water containing substantially no sodium chloride. Here, “water” is tap water, groundwater, underground water, demineralized water, distilled water, purified water (RO water, membrane-treated water), a mixed water thereof, or the like, which does not substantially contain sodium chloride. Means

"Substantially free of sodium chloride"
Means that there is no artificial addition of sodium chloride. In this case, a small amount of sodium chloride naturally contained in water is not considered.

The fact that sodium chloride is not added artificially means that the sodium ion concentration of the water to which hydrochloric acid has been added does not exceed the sodium ion concentration contained in the "water". I have. For example,
Such “water” generally has a sodium ion concentration of 20%.
Since the concentration is 0 ppm or less, the water to which hydrochloric acid of the present invention is added also has a sodium ion concentration of 200 ppm or less.

The concentration of hydrogen chloride in water to which hydrochloric acid has been added is desirably 0.01% or more, particularly 0.1% or more, in order to cause an appropriate reaction. However, when pursuing economy, the concentration of hydrogen chloride is desirably 1.0% or more and 21.0% or less. That is, if the hydrogen chloride concentration is 1.0% or more,
It is possible to obtain an industrially stable reaction.
This is because if it is 1.0% or less, it does not emit smoke at normal temperature and is desirable in terms of storage and handling.

After passing the water to which such hydrochloric acid is added through a non-diaphragm electrolytic cell, a current is applied to both the positive and negative electrodes to perform electrolysis.
In addition, the non-diaphragm electrolytic cell is an electrolytic cell having no diaphragm. This non-diaphragm electrolytic cell may be a monopolar electrolytic cell,
It is desirable to use a bipolar electrolytic cell.

In general, there are two types of methods for connecting a plurality of electrodes in an electrolytic cell, a monopolar type and a bipolar type. The monopolar type is a type in which all of the electrodes are connected to either the cathode or the anode of the power supply, and the dipolar type has, for example, a structure in which a plurality of electrodes are superposed at regular intervals and insulated from each other. And the electrode connected to the anode of the power supply (ie the anode)
In this method, at least one intermediate electrode that is not connected to any of the electrodes exists between the power supply and the electrode connected to the cathode of the power supply (that is, the cathode).

In the electrolysis, it is desirable that the voltage per pair of electrodes is not less than 1.5 volts and not more than 4.0 volts. In the case of a bipolar electrolytic cell, an intermediate electrode exists between the cathode and the anode as described above,
"Voltage per pair of electrodes" means cathode, anode,
And a voltage between two adjacent electrodes including the intermediate electrode.

Generally, when the voltage per pair of electrodes is increased, chlorine starts to be generated at 1.3 volts or more, and reaches the maximum at 1.5 volts or more. Therefore, the voltage per pair of electrodes is desirably 1.5 volts or more. When the voltage exceeds 4.0 volts, oxygen starts to be generated, and when the voltage exceeds 5.0 volts, ozone starts to be generated. Since generation of ozone is not desirable, the voltage is desirably 5.0 volts or less. Further, since the generation of oxygen wastes power, it is particularly desirable that the voltage be 4.0 volts or less. Note that the voltage is preferably 3.0 volts or less from an economic viewpoint. At least, since generation of ozone is not preferable in terms of working environment, the voltage is desirably 5.0 volts or less, and the electrolyzed water used in the present invention is preferably ozone-free electrolyzed water.

After producing the electrolyzed water in this way, the obtained electrolyzed water is diluted. Generally, in the production of electrolyzed water, it is desirable from the viewpoint of economy that only a small amount of water having a high chlorine concentration is produced and then used after dilution. Therefore, after the electrolysis, the electrolyzed water is collected after dilution. The degree of dilution is such that the pH is 4.0 or more, preferably 4.5 to 7.0, and the effective chlorine concentration is 10 to 30 p.
It is preferable to dilute so as to be in the range of pm.

The electrolyzed water produced by the production method of the present invention does not lose its sterilizing effect even if the effective chlorine concentration is diluted to a concentration of 1 ppm to 2 ppm. still,
The available chlorine concentration is determined by the ortho-tolidine method (edited by the Pharmaceutical Society of Japan,
"Hygiene Test Method / Comment 1980", page 746, Kanehara Publishing Co., Ltd., March 20, 1980) or iodine titration method (Japan Water Works Association, "Water Water Test Method 1993 Edition", pages 218 to 219) , November 15, 1993).

The electrolyzed water may be neutralized with a neutralizing agent. When electrolyzed water having a high effective chlorine concentration is obtained, the pH of the electrolyzed water may be lowered. However, it is generally known that water in which chlorine is dissolved changes its bactericidal activity depending on the pH ( Published by Fuji Techno System Co., Ltd.
"Microbial Control Technical Data Collection of Food Industry", No. 242-
243 page, 1977), and the pH of the electrolyzed water is preferably 7.0 or less, preferably 6.5 or less, because the sterilizing power becomes high. Also, if the electrolyzed water is strongly acidic,
Because it will be restricted by the place and method used,
The pH of the electrolyzed water is preferably 4.0 or more, and more preferably 4.5 or more. Alkaline chemicals are suitable as such a neutralizing agent, and sodium hydroxide, potassium hydroxide, sodium bicarbonate, sodium carbonate and the like can be used, but sodium hydroxide is most preferable.
When neutralizing electrolyzed water in this way, the addition of a neutralizing agent
Although it may be before or after dilution, the latter is more desirable.

The above operation can be performed by, for example, Pure Star (trademark, manufactured by Morinaga Engineering Co., Ltd .; the same applies hereinafter), which is a commercially available electrolyzed water producing apparatus. This apparatus is provided with a tank storing 21% hydrochloric acid or 3% hydrochloric acid. In the former case, 21% hydrochloric acid is diluted with water and then passed through a non-diaphragm electrolytic cell. In the latter case, 3% hydrochloric acid itself is "water to which hydrochloric acid is added". Water is passed through the diaphragm-free electrolytic cell. Then, it is possible to produce electrolyzed water by electrolysis continuously. In this case, the obtained electrolyzed water has a pH of 4.0 or more, preferably pH 4.0.
The electrolysis conditions of the non-diaphragm electrolytic cell are adjusted and the electrolyzed water is diluted under the conditions of 5 to 6.8 and an effective chlorine concentration of 10 to 30 ppm.

The electrolyzed water thus obtained is substantially free of sodium chloride, and has a pH near neutral, which is higher than that of the conventional electrolyzed water 1 or 2. Has properties similar to natural water. Therefore, it can be suitably used in the present invention.

As an apparatus for producing ice using electrolyzed water as described above, a refrigeration apparatus capable of controlling the temperature can be exemplified. Also, when making ice from electrolyzed water,
It is preferable to add the electrolyzed water to a stainless steel container or the like and make ice in a freezer.

Next, the present invention will be described in detail with reference to test examples.
In the present invention, the following test method was adopted as a method for measuring the concentration of hypochlorous acid. That is, the hypochlorous acid concentration (so-called residual chlorine concentration) in the sample is determined according to Japanese Industrial Standards (hereinafter JIS).
Abbreviated. ) It was measured as follows by an iodine titration method described in Section 33.3 of K0102.

(A) Appropriate amount of sample (0.1 to 7 as Cl)
mg. ) In a 500 ml stoppered Erlenmeyer flask,
Distilled water is added to about 300 ml, and 1 g of potassium iodide specified in JIS K8913 and 5 ml of acetic acid (1 + 1) specified in JIS K8355 are added. (B) Plug and mix by shaking and leave in the dark for about 5 minutes. (C) The released iodine was titrated with a 10 mmol / l sodium thiosulfate solution.
Add 1 ml of starch solution (10 g / l) as indicator and titrate until the blue color of the resulting iodine starch disappears. (D) As a blank test, take 100 ml of distilled water, and
Perform the operation of (c). (E) The concentration of residual chlorine in the sample (mgC
1 / l; so-called ppm concentration of hypochlorous acid) is calculated.

A = (ab) × f × 1000 / V × 0.3545

In the above formula, A is the concentration of residual chlorine (mgCl / l), and a is 10 mmol / l required for titration.
Sodium thiosulfate solution (ml), b: 10 mmol / l sodium thiosulfate solution (ml) required for blank test, f
Is a factor of a 10 mmol / l sodium thiosulfate solution, V is a sample (ml), and a constant of 0.3545 is 10 mm.
It shows the residual chlorine equivalent (mg) of 1 ml of an ol / l sodium thiosulfate solution.

Test Example 1 This test was carried out to examine a method for producing electrolytic water ice in which the functions of the electrolytic water such as the effective chlorine concentration and the pH were suppressed from being lowered even when it was melted. (1) Preparation of Sample Electrolyzed water having an effective chlorine concentration of 12 ppm and a pH of 7.0 was produced using a commercially available electrolyzed water producing apparatus Purestar, and a stainless steel container (2 inches in diameter, 140 mm in height, 1 m in thickness) was prepared.
m) were prepared by adding 230 ml.

One of them was placed in a freezer at −10 ° C. and frozen to form electrolytic water ice. Similarly, electrolyzed water ice frozen in a -20 ° C freezer and a -40 ° C freezer was used as Samples 2 and 3.

(2) Test Method Each sample was melted at 20 ° C., and the effective chlorine concentration and pH remaining in each sample were measured. In addition, the available chlorine concentration remaining in each sample was expressed as a ratio to the available chlorine concentration before freezing (residual available chlorine concentration ratio).

(3) Test Results The results of this test are as shown in Table 1. Table 1 shows the measurement results of the residual effective chlorine concentration ratio and the pH of each sample.

As is clear from Table 1, no change in the pH before freezing was observed in any of the samples. However, Sample 3 manufactured under cooling conditions of -40 ° C. showed the hypochlorous acid remaining in the melt. It is clear that the acid concentration is high.

As a result of this test, the electrolyzed water was placed under cooling conditions of -40 ° C. or less, and frozen under the cooling conditions, so that hypochlorous acid remained for a long time even after thawing,
It was found that electrolyzed water ice in which a decrease in electrolyzed water function was suppressed was obtained.

[0047]

[Table 1]

Test Example 2 This test was performed to confirm the relationship between the conditions for melting electrolytic water ice and the effective chlorine concentration, pH, etc. after melting. (1) Preparation of Samples Three samples identical to Sample 3 in Test Example 1 were prepared, and each was allowed to melt in an environment of 30 ° C., 17 ° C., and 12 ° C. Samples 4 to 6 were used.

(2) Test Method The effective chlorine concentration and pH remaining in each sample were measured.
In addition, the available chlorine concentration remaining in each sample was expressed as a ratio to the available chlorine concentration before freezing (residual available chlorine concentration ratio).

(3) Test Results The results of this test are as shown in Table 2. Table 2 shows the measurement results of the residual effective chlorine concentration ratio and the pH of each sample.

As is clear from Table 2, no change in pH was observed before freezing in each sample, and no significant difference was observed in the concentration of hypochlorous acid remaining in the melt in any of the samples. It is clear that.

As a result of this test, the electrolyzed water was placed under cooling conditions of -40 ° C. or less, and the electrolyzed water ice obtained by freezing under the cooling conditions was treated with hypochlorite regardless of the melting conditions. It has been found that the acid remains for a long time and the decrease in the function of the electrolyzed water is suppressed.

[0053]

[Table 2]

Next, the present invention will be described in detail with reference to examples, but the present invention is not limited to the following examples.

[0055]

EXAMPLE 1 Tap water flow rate of 1.2 m ^{3 /} h, electrolyte flow rate of 1.8 l / h, 2
An electrolyzed water producing apparatus Purestar was operated under the conditions of a flow rate of 1 ml of hydrochloric acid of 100 ml / hour and a current of 12 amperes, and electrolyzed water having a hypochlorous acid concentration of 12 ppm, a pH of 6.5 to 7.0 and a liquid temperature of 15 ° C. was continuously fed. Manufactured and supplied this electrolyzed water via a pipeline and a metering pump directly connected to a water supply pipe of a small ice making device (Hoshizaki Cube Star: manufactured by Hoshizaki Electric Co., Ltd.), and maintained at −40 ° C. To continuously produce a 3 cm cuboid of electrolytic water ice.

[0056]

According to the method for producing electrolyzed water of the present invention, the deactivation of chlorine is suppressed in the step of freezing electrolyzed water, and it is possible to suppress a decrease in the function of electrolyzed water, and it is possible to melt the water. Hypochlorous acid present in the subsequent melt stays for a long time,
Electrolyzed water ice in which effects such as sterilization are maintained can be obtained. Such electrolyzed water ice is suitable for preserving fresh foods and the like because the effect of the sterilizing power is maintained for a long time.

Continuation of the front page F term (reference) 4B022 LA05 LA06 LP08 4D061 DA02 DA03 DB07 EA02 EB04 EB14 EB20 EB21 ED12 FA20

Claims (3)

[Claims] 1. A method for producing electrolyzed water ice, comprising placing electrolyzed water under cooling conditions of -40 ° C. or lower and freezing under said cooling conditions. 2. Electrolyzed water having a sodium ion concentration of 20
The method for producing electrolyzed water ice according to claim 1, wherein the electrolyzed water is 0 ppm or less and the pH is in a range of 4.5 to 6.8. 3. Electrolyzed water is produced by adding hydrochloric acid to water substantially free of sodium chloride, passing the water added with hydrochloric acid through a diaphragm-free electrolytic cell, electrolyzing, and diluting with water. The method for producing electrolyzed water ice according to claim 1 or 2, which is electrolyzed water.