JP2009126736A - Hydrogen-generating agent and its usage - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydrogen-generating agent for easily preparing hydrogen water suitable for drinking and having high concentration of dissolved hydrogen and less vaporization residue, in which an effect of eliminating active oxygen can be expected within several ten minutes after the agent is brought into contact with drink water such as tap water. <P>SOLUTION: The hydrogen-generating agent as the purpose can be obtained by mixing a metal hydride compound such as CaH<SB>2</SB>and a solid acid such as citric acid in a fused water-insoluble polymer compound such as polyethylene and then cooling and solidifying it. By bringing the hydrogen-generating agent into contact with tap water, hydrogen water suitable for drinking and having concentration of dissolved hydrogen of at least 0.2 ppm and vaporization residue of at most 500 ppm can be obtained within 30 minutes of contact. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a hydrogen generating agent suitable for adjusting hydrogen water for drinking by dissolving hydrogen in water in a short time by contacting with drinking water such as tap water.

It is said that water in which hydrogen is dissolved at a high concentration (hereinafter referred to as hydrogen water) has an antioxidant action, so if it is drunk, it eliminates active oxygen generated in the body and contributes to physiological health. This hydrogen water is also called reduced water because the oxidation-reduction potential (hereinafter abbreviated as ORP) indicates the value on the reduction side. In order to adjust such hydrogen water, (1) a method in which water is electrolyzed and hydrogen generated at the cathode is dissolved in water, and (2) a method in which hydrogen gas is directly dissolved in water are known.

  Since the method (2) does not require expensive equipment, various methods have been proposed recently. One of them is a method for adjusting hydrogen water by bringing metal magnesium (Mg) into contact with water to generate hydrogen (Patent Document 1). In addition, in order to make the hydrogen water obtained by the reaction of Mg and water alkaline, or in order to facilitate the generation of hydrogen by promoting the reaction of Mg and water, Mg powder and a solid acid are added with water solubility such as corn starch. An acid-reduced water-generating tablet formed into a tablet using a form is disclosed (Patent Document 2).

The present inventor has also prepared a hydrogen generator by embedding a metal hydride compound such as calcium hydride in a solid water-soluble compound such as polyethylene glycol or sugar, and dissolving it in water for easy hydrogenation. A method for adjusting water was proposed previously (Patent Document 3).
Patent Document 1: Japanese Patent Laid-Open No. 2002-336877 Patent Document 2: Japanese Patent Laid-Open No. 2005-052811 Patent Document 3: WO / 2007/055146

  It is said that the so-called antioxidant function in which hydrogen water reacts with an oxidizing agent such as an active radical and renders it harmless is more excellent as the concentration of dissolved hydrogen dissolved in water (hereinafter abbreviated as DH) increases. In the method using Mg disclosed in Patent Documents 1 and 2, the reaction between Mg and water is slow, and in order to make DH in hydrogen water obtained by using a large amount of Mg 0.2 ppm or more, water is used for several hours or more. It is necessary to react with it. It is very inconvenient to wait for several hours to add hydrogen generator to drinking water to prepare hydrogen water containing high concentration hydrogen.

  In order to solve this drawback, the present inventor proposed the use of a metal hydride compound such as calcium hydride (CaH2) in which the reaction with water instantaneously proceeds in Patent Document 3. However, since the technique disclosed in Patent Document 3 is a water-soluble compound that embeds CaH2 or the like to form a hydrogen generator, when dissolved in water such as drinking water, hydrogen water having a high DH can be quickly obtained. Although it can be adjusted, since the water-soluble compound used at the time of embedding is also dissolved in water, the obtained hydrogen water becomes water with much evaporation residue.

  On the other hand, the water supply law stipulates that the evaporation residue is 500 ppm or less as the water quality standard value. Therefore, in order to safely use hydrogen water prepared using a hydrogen generator as drinking water, it is desirable to adjust hydrogen water having an evaporation residue of 500 ppm or less. Therefore, the subject of this invention is development of the hydrogen generating agent which gives hydrogen water with high DH and safe as drinking water by contact with the water within several tens of minutes.

  When the present inventor uses a water-insoluble polymer compound instead of the water-soluble compound used in Patent Document 3, the metal hydride compound is dispersed and embedded in the polymer compound, thereby reacting the metal hydride compound with water. It was thought that hydrogen generated with a moderate delay can be effectively dissolved in water to obtain hydrogen water with high DH and little evaporation residue. In this case, an attempt was made to press-mold by simply mixing the metal hydride compound and the polymer compound powder in a solid state, but it is not possible to mold into a tablet without using a polymer plasticizer. It was possible. On the other hand, if the polymer compound was melted and the metal hydride compound was dispersed in the melt and cooled and solidified, a molded product in which the metal hydride compound was stably embedded could be obtained.

  However, in this method, when the amount of the metal hydride compound is small, since it is like an island floating in the sea of the polymer compound, it does not come into contact with water and is long to generate hydrogen. It turns out that it takes time. On the other hand, when a water-soluble solid acid is simultaneously dispersed and embedded in a polymer compound in order to neutralize the alkali metal salt generated by the reaction between the metal hydride compound and water, it is relatively short when contacted with water. The present invention was completed by finding that hydrogen was generated in time.

  That is, an object of the present invention is to use a hydrogen generator in which powdered alkali metal hydride or alkaline earth metal hydride and a water-soluble solid acid are mixed in a molten water-insoluble polymer and cooled and solidified. Solved by. Among the metal hydride compounds, it is preferable to use at least one of calcium hydride or magnesium hydride. Moreover, it is preferable to use anhydrous citric acid as the solid acid used in these hydrogen generators. Furthermore, polyethylene is preferable as the water-insoluble polymer used in these hydrogen generators. The form of these hydrogen generators is preferably a powder.

  In order to adjust the hydrogen water, the hydrogen generator is brought into contact with water to dissolve the hydrogen generated from the hydrogen generator in water. In this case, it is preferable to form the hydrogen generating agent in a powder form and fill it in a water permeable container and impregnated with powder particles and contact with water. Furthermore, it is preferable that a water-insoluble substance having a specific gravity greater than 1 coexists in the container so that the container filled with the powdered hydrogen generating agent settles in water and can easily come into contact with water.

  The reaction between the metal hydride compound and water was delayed by melting and mixing the water-insoluble polymer compound such as polyethylene with a metal hydride compound that reacts violently with water such as CaH2 and water-soluble solid acid. A hydrogen generator was obtained. By bringing the hydrogen generator of the present invention into contact with tap water for several tens of minutes, hydrogen water having a DH of 0.2 ppm or more and an evaporation residue of 500 ppm or less could be prepared. Therefore, this hydrogen water satisfies the water quality standard value stipulated in the Water Supply Law from the viewpoint of evaporation residue, and can be expected to be beneficially used as a safe drinking water that promotes human health.

  Examples of the alkali metal hydride used in the present invention include lithium hydride (LiH), sodium hydride (NaH), and potassium hydride (KH). Examples of the alkaline earth metal hydride include magnesium hydride (MgH2), calcium hydride (CaH2), barium hydride (BaH2), beryllium hydride (BeH2), and the like. Among these metal hydride compounds, MgH2 and CaH2 are relatively easy to handle, and when dissolved in water, MgH2 and Ca ions become safe and preferred compounds. These metal hydride compounds can also be used as a mixture. In the case of CaH2, which is a typical example, hydrogen is generated by reacting with water according to the following reaction formula.

  As is apparent from this reaction formula, CaH2 and MgH2 generate 2 mol of H2 from 1 mol of CaH2, but Mg generates only 1 to 1 mol of H2. In the present invention, a hydrogen generator containing these metal hydride compounds is brought into contact with water, and the generated H2 is dissolved as it is to prepare hydrogen water. Therefore, it is efficient to use a metal hydride compound with a large amount of H2 generated. Is.

  In that case, since the metal hydride compound such as CaH2 reacts instantaneously with water, the generated H2 is scattered in the air and hardly dissolved in water. In order to dissolve a high concentration of H2 in water, it is necessary to delay the reaction with water. Therefore, in the present invention, a metal hydride compound and a water-soluble solid acid are contained in a polymer compound that does not dissolve in water, which will be described later. This problem was solved by embedding. Further, by embedding with a polymer compound, a highly reactive metal hydride compound does not come into direct contact with air, so that it can be kept stable and easy to handle. In order to embed them uniformly in the polymer compound, it is necessary to use these metal hydride compounds in powder form.

  On the other hand, as can be seen from Chemical Formula 1, hydrogen water obtained because an alkali metal salt such as Ca (OH) 2 is produced by this reaction is alkaline and is therefore unsuitable for beverages. Therefore, a water-soluble solid acid is added to the hydrogen generator to neutralize the metal salt. These solid acids are preferably organic acids such as citric acid, adipic acid, succinic acid, succinic anhydride, fumaric acid, maleic acid, malic acid, tartaric acid, oxalic acid and malonic acid. In particular, adipic acid and citric acid are recognized as food additives, and thus are preferred solid acids for the hydrogen generator used for preparing hydrogen water for beverages, which is the main use of the present invention. These solid acids are preferably used in a powder form so as to be uniformly mixed in the polymer compound. It is also preferable to use an anhydrous acid. Furthermore, it is preferable to use an acid that does not decompose below the melting temperature of the polymer compound.

  Examples of water-insoluble polymer compounds used in the present invention include polyolefins such as polyethylene, polypropylene, and poly-1-butene, polyesters such as polyethylene terephthalate, polyethylene sebacate, and polydecamethylene adipate, and methacrylic resins such as polymethyl methacrylate and polyethyl methacrylate. Examples include polystyrene and polyvinyl chloride.

    These polymers are melted and the above-described metal hydride compound and solid acid are uniformly dispersed in the melt. In this case, it is preferable to use a polymer having a relatively low molecular weight because the lower the viscosity of the melt, the easier the stirring and mixing with the metal hydride compound and the solid acid. However, if it is too small, the formability deteriorates, which is not preferable. Further, in order to melt at a temperature at which thermal decomposition of the solid acid does not occur, the melting temperature is preferably low. From these viewpoints, it is preferable to use a crystalline polymer whose viscosity rapidly decreases at the melting point, and polyethylene (abbreviated as PE) is a preferred example.

  Next, the manufacturing method of the hydrogen generating agent of this invention using these materials is demonstrated. The polymer compound is heated and melted, and the solid acid and metal hydride compound powder are added to the melt, and the mixture is uniformly stirred and mixed. By cooling the mixture in a dry atmosphere, the molten mixture is solidified to obtain a hydrogen generator. At that time, it is preferable that the raw material polymer compound and the solid acid be dehydrated and dried in advance. If there is moisture in the raw material, it reacts with the metal hydride compound during mixing to generate hydrogen, which is not preferable because the active component of the metal hydride compound in the resulting hydrogen generator is reduced.

  Industrially, the hydrogen generator of the present invention can be easily produced by using a melt extruder. That is, a high-molecular compound, a solid acid, and a metal hydride compound are mixed and fed from a raw material inlet through an extruder equipped with a single or twin screw and a temperature-controllable barrel. The melt mixture may be extruded and cooled. At that time, by selecting the shape of the die, it is possible to produce a hydrogen generating agent having an arbitrary form such as a strand form or a film form.

  In order to adjust hydrogen water having a pH near neutral in a relatively short time of several tens of minutes by bringing the hydrogen generator of the present invention into contact with water, it is embedded in a water-insoluble polymer compound. It is necessary that the metal hydride compound reacts with water at the same time that the solid acid elutes easily into water. This problem could be solved by increasing the contact area between water and the hydrogen generating agent and appropriately selecting the composition in the hydrogen generating agent. One of the former solutions is to powder the cooled and solidified hydrogen generator. That is, it is achieved by pulverizing the hydrogen generating agent produced by the above-described method with an appropriate pulverizer.

  Next, selection of the composition will be described. The amount of the polymer compound in the hydrogen generator is preferably in the range of 20 to 50% by mass. A small amount of 20% or less is not preferable because the formability of the hydrogen generating agent deteriorates. If it is 50% or more, the elution rate of the embedded solid acid into water or the reaction between the metal hydride compound and water becomes too slow, which is not preferable. The amount of the metal hydride compound is preferably in the range of 5 to 30% although it depends on the kind of the compound. If it is 5% or less, it is difficult to adjust hydrogen water having a high DH, and if it is 30% or more, the shapeability is deteriorated and a large amount of solid acid necessary for neutralization is required, which is preferable for the reasons described below. Absent. The formability mentioned here means a state in which the metal hydride compound or solid acid is uniformly dispersed and embedded in the polymer compound, and for this purpose, the molten mixture can be stirred or kneaded. Is preferably maintained.

  The alkali metal salt produced by the reaction between the metal hydride compound and water is neutralized with a solid acid, so in order to adjust the neutral hydrogen water, theoretically, the solid acid necessary for neutralization must be determined according to the chemical reaction equation. What is necessary is just to disperse-mix with a hydrogen generating agent. On the other hand, the increase in the evaporation residue due to the addition of the hydrogen generator in hydrogen water is theoretically the sum of these water-soluble solid acids and metal ions of the metal hydride compound. The amount of solid acid and metal hydride compound is preferably small.

  For example, when 60 mg of CaH2 is used as the metal hydride compound, the number of moles of CaH2 is 1.43 × 10 −3. Since the same number of moles of calcium hydroxide is produced by reaction with water, the amount of solid acid to neutralize this is, for example, when citric acid, which is a tribasic acid, is used (2/3) × 1.43 × 10 − 3 moles. Therefore, if 183 mg of citric acid is added, a neutralization amount is obtained. On the other hand, when all of these compounds are eluted in water, the amount of elution is 60 × 0.95 + 183 = 240 mg. Therefore, the amount is 240 ppm with respect to 1 L of water, and it is assumed that these remain as evaporation residues. However, as shown in the examples below, when the hydrogen generator of the present invention is brought into contact with water, it is found that the evaporation residue is less than the above calculated value because not all solid acids are eluted in several tens of contacts. It was.

  According to the study of the present inventor, it has been found that even if the neutralization amount is added depending on the kind of the solid organic acid, the pH of the hydrogen water becomes weakly acidic or conversely alkaline. This is presumably because the mixed state of the organic acid and PE differs depending on the type of the organic acid. In the case of citric acid, hydrogen water tends to be weakly acidic even when an amount equal to the neutralization amount is added, but in the case of adipic acid, it shows alkalinity. That is, in the case of citric acid, since the affinity with PE is not good, it is assumed that the acid is eluted relatively quickly in the initial stage when it is brought into contact with water.

  Therefore, in order to obtain hydrogen water having a high DH, it is necessary to increase the amount of the metal hydride compound added to the hydrogen generating agent. Will increase. It is necessary to determine the composition of the hydrogen generating agent in consideration of this contradictory phenomenon and the elution rate of the solid acid.

  Next, a method for adjusting hydrogen water using the hydrogen generator of the present invention will be described. As is clear from what has been described so far, the hydrogen water can be adjusted by bringing the hydrogen generator into contact with water. In that case, it is desirable to make it contact with water in a sealed container so that generated hydrogen is not diffused into the air. For example, a method of sealing a bottle lid by adding water and a hydrogen generator into a PET bottle is preferable. Furthermore, it is preferable that the hydrogen generating agent settles on the bottom of the bottle so that hydrogen bubbles generated from the hydrogen generating agent are in good contact with water.

  When the hydrogen generating agent is powder, if the powder is used as it is, fine powder will be dispersed in the water, so it is necessary to separate it when drinking hydrogen water. In order to eliminate this inconvenience, a method of filling the powder in a container that allows water to permeate but does not permeate the powder particles and bringing it into contact with water is preferable. Examples of such a container include a bag-shaped container made of non-woven fabric and a container formed of a microporous material made of ceramic or plastic. In addition, the hydrogen generating agent tends to float on the water surface when it comes into contact with water to generate hydrogen bubbles, and when a polymer compound having a density lower than 1 such as polyethylene is used as an embedding material. Therefore, it is preferable that a substance having a specific gravity greater than 1 and not soluble in water is placed in the container together with the hydrogen generating agent in order to sink to the bottom of the water. Examples of such substances include natural stones such as barley stone, tourmaline stone and coral, glass and ceramics.

  The present invention will be described in more detail with reference to the following examples, but the technical scope of the present invention is not limited to these examples. In addition, the measurement of ORP used in the examples is a value measured using an ORP meter (Toko Chemical Laboratories) and corrected to a standard electrode standard. DH was measured with a portable dissolved hydrogen meter (Toa DKK Corporation) using a dissolved hydrogen electrode. Further, polyethylene (PE) used in the examples is trade name Sun Wax 131-P (manufactured by Sanyo Chemical Industries). Moreover,% is the mass% unless there is a notice.

  A predetermined amount of powdered PE and powdered solid acid was weighed in an aluminum dish, and the PE was melted on a hot plate whose surface temperature was adjusted to 150 ° C. and stirred with boiling to disperse and mix the solid acid. Then, a predetermined amount of powdered CaH2 was added as a metal hydride compound and mixed with stirring. After mixing uniformly, the aluminum dish was lowered from the hot plate and cooled in a desiccator to solidify the molten mixture. The hydrogen generator solidified in a block shape was pulverized with a desktop mixer to prepare a powdered hydrogen generator that passed through a sieve having an aperture of 0.74 mm (A to E).

  This hydrogen generator is weighed in a predetermined amount so that CaH2 is 45 mg for A and B, and 50 mg for C, D, and E, and heat-sealed on the three sides of the thin nonwoven fabric. At the same time, two barley stones having a diameter of 1 cm were put, and the opening of the bag was heat-sealed and sealed. The above bag was put in a 500 ml PET bottle, 500 ml of tap water was injected, sealed with a lid, and contacted with water for 20 minutes. It was observed that the bag settled to the bottom of the water and bubbles assumed to be hydrogen were generated from the bag. After 20 minutes, DH, ORP and pH in the hydrogen water were measured. The composition of the hydrogen generator is summarized in Table 1, and the evaluation results of the characteristics are summarized in Table 2.

In the same manner as in Example 1, 30% PE, 50% citric acid anhydride as a solid acid, and 20% CaH2 were melt-mixed and cooled and solidified, and then powdered to prepare hydrogen generator F. Sample in which a hydrogen generator was weighed so as to contain 300 mg (CaH2: 60 mg) (F-1) and 350 mg (CaH2: 70 mg) (F-2) in the same manner as in Example 1 and filled in a bag together with barley stone Adjusted. In the same manner as in Example 1, it was brought into contact with water for a predetermined time in a PET bottle containing 500 ml of tap water. After a predetermined time (10 to 30 minutes), DH, ORP, and pH were measured in the same manner. Further, about 30 g of hydrogen water brought into contact with water for 2.5 hours and 4 days was collected in an aluminum dish, and the evaporation residue was measured. The results are summarized in Table 3. Table 3 also shows the results of measurement in the same manner for water (tap water) in which a sample prepared by putting only barley stone (2 pieces) in a bag as a blank was brought into contact with tap water with a PET bottle.

  Hydrogen generators G and H were produced in the same manner as in Example 1 using MgH 2 and LiH as the metal hydride compound. A sample was prepared by filling a similar bag with a predetermined amount of a powdered hydrogen generator and barleystone. In this case, in order to compare with the characteristics of the sample (F-1) of Example 2, the amount of the hydrogen generating agent is equal to the amount of hydrogen generated from 60 mg of CaH2 in the number of moles of hydrogen generated by the reaction with water. Adjusted as follows. On the other hand, for comparison with the prior art, a sample (J) in which 350 mg of metal Mg powder (reagent, 40 mesh) was filled in a bag together with stones, and a sample (K) in which 70 mg of Mg powder and 370 mg of anhydrous citric acid were filled together with stones (K) ) Was adjusted.

  The amount of Mg 70 mg in sample K is the amount of hydrogen generated by reacting with water equal to the number of moles of hydrogen similarly generated from 60 mg of CaH2, and is used to promote the reaction with water or an alkali salt. A sample to which citric acid has been added to neutralize Further, if the amount of Mg in sample J is completely reacted, it corresponds to the amount of hydrogen that is five times the amount of hydrogen generated from 60 mg of CaH2.

The bag filled with these hydrogen generators was immersed in tap water in a PET bottle for 30 minutes in the same manner as in Example 1, hydrogen water was adjusted, and its characteristics were measured in the same manner as in Example 2. Table 4 shows the compositions of the hydrogen generators G and H, and Table 5 summarizes the characteristics of the obtained hydrogen water. In addition, the evaporation residue shown in Table 5 is a value for hydrogen water after immersion for 2.5 hours. From these results, Mg metal powder reacts slowly with water, and it is difficult to obtain hydrogen water with high DH within several tens of minutes. In addition, when citric acid is added and contacted with acidic water, it reacts. However, it has been clarified that DH is lower than hydrogen water obtained from the hydrogen generator of the present invention.

  According to the hydrogen generator of the present invention and the method for adjusting hydrogen water using the same, the hydrogen water for beverages containing DH of 0.2 ppm or more and having little evaporation residue as defined by the Waterworks Law is within tens of minutes. Can be adjusted. Since hydrogen water with high DH eliminates active oxygen, it is expected to be used as a health drink that promotes human health.

Claims (8)

  A hydrogen generating agent obtained by uniformly mixing a powdered alkali metal hydride or alkaline earth metal hydride and a water-soluble solid acid into a molten water-insoluble polymer and solidifying by cooling.   2. The hydrogen generator according to claim 1, wherein the alkaline earth metal hydride is one or more selected from calcium hydride or magnesium hydride.   The hydrogen generator according to claim 1 or 2, wherein the solid acid is anhydrous citric acid.   4. The hydrogen generator according to claim 1, wherein the water-insoluble polymer is polyethylene.   6. The hydrogen generating agent according to claim 1, wherein the hydrogen generating agent is in a powder form.   A method for preparing hydrogen-dissolved water, wherein the hydrogen generating agent according to claim 1 is brought into contact with water to dissolve hydrogen in water.   The method for adjusting hydrogen-dissolved water according to claim 6, wherein the powdered hydrogen generator is filled in a water-permeable and powder particle-impermeable container.   The method for adjusting hydrogen-dissolved water according to claim 7, wherein a water-insoluble substance having a specific gravity greater than 1 is allowed to coexist in the container so that the container settles in water.