Hydrogen generating material and method for manufacturing the same

Abstract

To provide a hydrogen generating material capable of supplying more hydrogen even in applications where the usage time is short.SOLUTION: A hydrogen generating material is characterized by containing a hydrogen generator that generates molecular hydrogen by reacting with water and containing a water-absorbing resin.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a novel hydrogen generation material. More specifically, it relates to a material that generates hydrogen when contacted with water or a liquid containing water.

Background Art

[0002] In recent years, it has become clear that various beneficial effects can be obtained on the human body when hydrogen gas or water or a liquid containing hydrogen acts on the human body. For this reason, various materials for generating hydrogen, products sealed with hydrogen, etc. have been proposed.

[0003] For example, a hydrogen generation material that generates hydrogen by contacting with water, comprising (1) a) hydrogen generation particles capable of reacting with water to generate hydrogen, b) a coating resin, and c) a matrix resin, and (2) at least the surface of the hydrogen generation particles protruding from the surface of the material is covered with a coating layer containing a coating resin, is known (Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in a hydrogen generation material such as the prior art, the hydrogen generation rate is slow, and it is difficult to supply a sufficient amount of hydrogen in a short time. Therefore, such a hydrogen generation material is not suitable for applications with a short usage time, for example.

[0006] Therefore, the main object of the present invention is to provide a hydrogen generation material capable of supplying more hydrogen even in applications with a short usage time.

Means for Solving the Problems

[0007] In light of the problems of the prior art, the inventors conducted extensive research and, as a result, discovered that a material having a specific structure can achieve the above objective, thus completing the present invention.

[0008] In other words, the present invention relates to the following hydrogen generating material. 1. A hydrogen generating material characterized by containing a hydrogen generating agent that reacts with water to generate molecular hydrogen, and a water-absorbing resin. 2. The hydrogen generating material according to item 1, wherein the hydrogen generating agent is at least one of a metal and a metal hydride. 3. The hydrogen generating material according to item 1 or 2, wherein the hydrogen generating agent is in particulate form and the volume average particle diameter of the particles is 1 to 100 μm. 4. The hydrogen generating material according to any one of items 1 to 3, wherein the water-absorbing resin includes a polyalkylene oxide resin. 5. The hydrogen generating material according to any one of items 1 to 4, wherein the water-absorbing resin further comprises at least one of polyolefin resin or styrene resin. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a hydrogen generating material that can supply more hydrogen even in applications with short usage times. In particular, since the present invention uses a water-absorbing resin as a support for the hydrogen generating agent, the opportunities (frequency) for the hydrogen generating agent to come into contact with water in the material of the present invention are increased, thereby enabling effective hydrogen generation. [Modes for carrying out the invention]

[0010] The hydrogen generating material of the present invention (the material of the present invention) is characterized by comprising a hydrogen generating agent that reacts with water to generate molecular hydrogen and a water-absorbing resin. Therefore, although the material of the present invention is basically composed of a hydrogen generating agent and a water-absorbing resin, other components (resin components, additives, etc.) may be included as long as they do not hinder the effects of the present invention.

[0011] The hydrogen generating agent is not limited to any substance that reacts with water to supply molecular hydrogen, and at least one of metals and metal hydrides (metal hydrides) can be preferably used. Here, the water may be liquid water (H2O) (pure water, tap water, etc.), water contained in a water-containing composition (aqueous solution or aqueous dispersion), water vapor, etc.

[0012] Examples of metals include at least one selected from the group consisting of elemental metals such as magnesium and aluminum, and alloys containing them.

[0013] Examples of metal hydrides include magnesium hydride, calcium hydride, barium hydride, beryllium hydride, strontium hydride, lithium hydride, sodium hydride, sodium borohydride, sodium lithium hydride, silicon hydride, and aluminum hydride. These can be used individually or in combination of two or more.

[0014] The form of the hydrogen generating agent is not particularly limited, but it is usually preferably in powder form. In this case, the average particle size of the particles constituting the powder is not particularly limited, but for example, a volume average particle size of 1 to 100 μm is preferred. Therefore, for example, particles with a volume average particle size of 10 to 50 μm can also be suitably used. If the volume average particle size is less than 1 μm, the particles tend to aggregate, which may reduce their dispersibility in the water-absorbent resin. Also, if the average particle size exceeds 100 μm, the weight of the particles may affect the dispersibility in the resin. Here, the volume average particle size is the value calculated as the average particle size D50 (50% particle size) from the result of the volume cumulative particle size distribution of the particle group measured by laser diffraction.

[0015] Furthermore, the particles may consist solely of the above-mentioned metals or metal hydrides, but as long as the effects of the present invention are not hindered, they may also be in the form of granules in which the particles are kneaded with a resin, or in the form of composite particles in which the surface of the particles is coated with a resin or the like.

[0016] The hydrogen generating agent content in the material of the present invention can be appropriately set according to the desired amount of hydrogen generated, etc. For example, it can be set to about 0.1 to 10% by weight in the material of the present invention, but is not limited to this. By setting it within this range, the dispersibility of the hydrogen generating agent can be increased, and a higher hydrogen generation rate can be obtained.

[0017] Superabsorbent polymers function particularly as a support for hydrogen generating agents and also have the function of promoting contact with water. For this reason, superabsorbent polymers can function as a support by encapsulating hydrogen generating agents or by dispersing hydrogen generating agents within them.

[0018] The water-absorbing resin is not particularly limited as long as it is a resin material that claims to have water-absorbing properties, but at least one of the following can be suitably used as the water-absorbing resin (water-absorbing resin of the present invention): for example, acrylic acid-vinyl alcohol copolymer, polyalkylene oxide resin, polyethylene oxide resin, polyvinyl alcohol resin, etc. Among these, polyalkylene oxide resin (for example, modified polyalkylene oxide) is more preferable because it is easy to handle during compounding and can impart water-absorbing properties to the base resin with a relatively small amount of compounding.

[0019] In this invention, an absorbent resin is defined as an absorbent resin (granular or sheet-like) that has been thoroughly dried in a desiccator, immersed in a sufficient amount of pure water (23°C), removed after 24 hours, and with the surface moisture wiped off, whose weight (water absorption rate) increases by 0.2% or more compared to the original absorbent resin.

[0020] The content of the water-absorbing resin in the material of the present invention can be appropriately set according to, for example, the type of hydrogen generating agent used, the desired amount of hydrogen generated, etc. Therefore, it can be set within a range of, for example, 20 to 99.9% by weight (and even 30 to 95% by mass), but is not limited thereto.

[0021] In the material of the present invention, for the purpose of mainly controlling the water absorption rate and improving strength, processability, etc., at least one resin such as styrene resin, polyester resin (such as polyethylene terephthalate), polyolefin resin (such as polyethylene, polypropylene), polyethylene glycol, etc. may be appropriately used in combination separately from the above water-absorbing resin (especially the water-absorbing resin of the present invention). The blending amount of these resins can be, for example, about 30 to 80% by weight in the material of the present invention, but is not limited thereto.

[0022] Also, in the present invention, if necessary, a water absorbent such as starch, cellulose, etc. can be used in combination. For example, a resin composition with enhanced water absorption obtained by adding it to a resin with relatively low water absorption (such as polyolefin resins such as polyethylene and polypropylene, styrene resin, etc.) can also be used. The addition amount of the water absorbent in this case is not particularly limited, but usually can be about 5 to 50 parts by weight with respect to 100 parts by weight of the resin.

[0023] The form of the material of the present invention is not particularly limited within the range that does not hinder the effects of the present invention, and can be, for example, powdery (granulated product), molded body, etc.

[0024] The manufacturing method of the material of the present invention is not particularly limited, and can be appropriately selected according to, for example, the desired form, the type of raw materials used, etc.

[0025] Generally, a method including a step of adding a hydrogen generator to a resin component containing a water-absorbing resin may be adopted. For the addition method, various devices such as known or commercially available mixers, kneaders, etc. can be used.

[0026] The method of adding the hydrogen generator is not particularly limited. For example, a) a method of kneading the hydrogen generator with a thermoplastic resin component (for example, a melt containing a water-absorbing resin), b) a method of dispersing the hydrogen generator in a solution in which the resin component (such as a water-absorbing resin) is dissolved in a solvent or a dispersion liquid dispersed in a solvent, etc. can be adopted.

[0027] After mixing, the mixture can be molded into the desired shape as needed. For example, known molding methods such as press molding and extrusion molding can be employed.

[0028] For example, the material of the present invention can be provided as a sheet-shaped molded body. When the material of the present invention is in sheet form, its thickness is not limited, but for example, if it is in the range of 0.1 to 10 mm, hydrogen can be supplied efficiently to the hydrogen supply destination without excess or deficiency.

[0029] In the materials of the present invention, generally, the more hydrogen generating agent is contained, the more hydrogen generating agent is exposed on the surface, making it more reactive with water. From this viewpoint, as mentioned above, the hydrogen generating agent content can be, for example, about 0.1 to 10% by weight.

[0030] Furthermore, a laminated form can be adopted in which one or more layers selected from the group consisting of, for example, paper, metal cans, metal plates, metal foils, metal vapor-deposited films, nonwoven fabrics, cloths, and resins are laminated on one or both sides of the sheet-like molded body.

[0031] Furthermore, the material of the present invention may be used in a flat sheet form, but it may also be molded into an embossed shape or into a container shape. It may also be foamed to form a foamed material.

[0032] Furthermore, the material of the present invention can also take the form of particulate matter (granules). In this case, the size of the granules is not particularly limited, but for example, a volume-average particle diameter of about 0.1 to 10 mm is preferred. If the volume-average particle diameter is less than 0.1 mm, the granules are prone to becoming airborne, which may reduce workability. Also, if it exceeds 10 mm, the surface area per unit weight is small, which may reduce the hydrogen generation rate. By having the above configuration, the material of the present invention increases the hydrogen generation rate, that is, the amount of hydrogen generated in a short time increases.

[0033] In the material of the present invention, the target to which the generated hydrogen is utilized (hydrogen supply destination) can be any object to which hydrogen is supplied by direct or indirect contact with the material of the present invention. In particular, it is preferable that the physical properties of the object can be maintained or improved by the action of hydrogen (e.g., reduction).

[0034] Furthermore, the hydrogen supply source may be water or a liquid containing water, or a solid or gas containing water. Therefore, examples of hydrogen supply sources include, for example, a) food ingredients such as beverages, meats, seafood, vegetables, and fruits, and b) processed foods made from the aforementioned food ingredients, as well as fresh flowers, fungi, bacteria, plant seeds, blood for transfusion, intravenous fluids, bath water, laundry water, detergents, air, wound dressings, cosmetics, diapers, pet beverages, aquarium water, microorganisms, soil, feed, indoor spaces, the human body, animals, plants, etc. These can serve as both hydrogen supply sources and water sources for hydrogen generating materials, but the water source and the hydrogen supply source may be different. In particular, it is preferable that the hydrogen supply source is a water source for hydrogen generating materials. [Examples]

[0035] Examples and comparative examples are shown below to give a more detailed explanation of the features of the present invention. However, the scope of the present invention is not limited to the examples.

[0036] Example 1 A magnesium hydride-containing compound was prepared by kneading commercially available magnesium hydride powder (Wako Pure Chemical Industries, Ltd., volume average particle size D50: 15 μm) into a modified polyalkylene oxide-based superabsorbent polymer (Sumitomo Seika Co., Ltd., "Aquacool TWB"). The ratio of magnesium hydride powder to the total amount of superabsorbent polymer was 6% by weight. A magnesium hydride-containing compound was freeze-dried and pulverized to obtain a water-absorbing hydrogen-generating material with a particle size of 10 mm or less. The water absorption capacity (moisture content when absorbing water) of the raw material resin was 2000%.

[0037] Example 2 A magnesium hydride-containing compound was prepared by melting and kneading commercially available magnesium hydride powder (Wako Pure Chemical Industries, Ltd., volume average particle size D50: 15 μm) with a pre-mixed resin containing 68% by weight of commercially available polyethylene resin (Prime Polymer Co., Ltd. "SP2020") and 32% by weight of modified polyalkylene oxide-based superabsorbent resin (Sumitomo Seika Co., Ltd. "Aquacool TWB", water absorption rate: approximately 3100% by weight). The proportion of magnesium hydride powder in this compound was 5% by weight relative to the total amount of the mixed resin. A magnesium hydride-containing compound was thoroughly dried and then melt-extruded to form a film (approximately 1 mm thick) to obtain a water-absorbing hydrogen-generating material. The magnesium hydride powder content was 5% by weight of the water-absorbing hydrogen-generating material, and the water-absorbing resin content was approximately 30% by weight. The water absorption capacity of the raw material mixture was 700%.

[0038] Comparative Example 1 A magnesium hydride-containing compound was prepared by kneading commercially available magnesium hydride powder (Wako Pure Chemical Industries, Ltd., volume-average particle size D50: 15 μm) into commercially available polyethylene resin. The ratio of magnesium hydride powder to the total amount of polyethylene resin was 6% by weight. The particle size of the resulting hydrogen-generating material was 10 mm or less. The water absorption capacity of the raw material resin was 0.05%.

[0039] Comparative Example 2 A magnesium hydride-containing compound was prepared by kneading commercially available magnesium hydride powder (Wako Pure Chemical Industries, Ltd., volume-average particle size D50: 15 μm) into commercially available polyethylene resin. The ratio of magnesium hydride powder to polyethylene resin was 5% by weight. The magnesium hydride-containing compound was formed into a film (approximately 1 mm thick) by melt extrusion molding to obtain a hydrogen-generating material.

[0040] Test Example 1 The hydrogen generation capacity of the samples obtained in each example and comparative example was evaluated using the following procedure. First, 1 g of the sample was placed in a 500 mL Erlenmeyer flask with a ground-glass joint, and then the flask was filled with pure water up to the mouth. Next, a specially made ground-glass joint lid that penetrates a glass tube was placed over it. As a result, when the lid was placed over the flask, the pure water in the flask overflowed, and the gas layer inside the flask was removed. Subsequently, the internal pressure increased due to hydrogen generation, and the pure water was discharged through the glass tube. The samples were stored in a room where the temperature was controlled to approximately 20°C, and after 4 hours, the dissolved hydrogen concentration and the amount of hydrogen gas that did not dissolve in the water were measured. The dissolved hydrogen concentration was measured using a dissolved hydrogen sensor (product name "H2-500sensor", manufactured by UNISENSE, a dissolved hydrogen concentration measuring device using a diaphragm electrode method). The dissolved hydrogen concentration and the amount of hydrogen gas that did not dissolve in the water were compared as values ​​obtained by dividing the magnesium hydride concentration (weight %) of each sample, i.e., the amount of hydrogen generated per unit amount of magnesium hydride. The results are shown in Table 1.

[0041] [Table 1]

[0042] As is clear from the results in Table 1, the hydrogen generating material of the present invention can supply a larger amount of hydrogen in a relatively short time of 4 hours by incorporating a hydrogen generating agent into the water-absorbing resin.

Claims

1. A hydrogen generating material characterized by containing a hydrogen generating agent that reacts with water to generate molecular hydrogen, and a modified polyalkylene oxide resin as a water-absorbing resin.

2. The hydrogen generating material according to claim 1, wherein the hydrogen generating agent is at least one of a metal and a metal hydride.

3. The hydrogen generating agent is in particulate form, and the volume-average particle diameter of the particles is 1 to 100 μm, according to claim 1 or 2.

4. The hydrogen generating material according to any one of claims 1 to 3, wherein the content of the hydrogen generating agent is 0.1 to 10% by weight, and the content of the water-absorbing resin is 20 to 99.9% by weight.

5. The hydrogen generating material according to any one of claims 1 to 4, further comprising at least one of a polyolefin resin and a styrene resin.

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