JP4739959B2 - Hydrogen gas detection material, hydrogen gas detection member, and hydrogen gas leak detection method - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a hydrogen gas detection material and detection member capable of easily and reliably detecting hydrogen gas leakage in an apparatus / equipment using hydrogen gas such as a fuel cell system, and a hydrogen gas leakage detection method. It is.

  For hydrogen contained in metal materials, etc., the amount of hydrogen released from the material to be inspected can be measured in a certain temperature range by using a temperature rising analysis method such as API-MS (atmospheric pressure ionization mass spectrometry) or an electrochemical permeation method. It can be confirmed by asking. However, tritium autoradiography, secondary ion mass spectrometry (SIMS), and the like are adopted for the partial hydrogen content of the material because a simple local analysis method using specific X-rays or the like cannot be applied. The former is a method for visualizing the location of hydrogen using tritium, and the latter is a method for irradiating a subject with ions of several keV to several tens keV and mass-analyzing the released ions. According to the above, hydrogen contained in a minute region can be detected on the order of ppm.

  As other hydrogen visualization methods, a silver decoration method and a hydrogen microprint method are also known. The former is a method that uses silver particles produced by hydrogen reduction of silver dicyanide for hydrogen visualization, and the latter is an electron microscope that observes silver particles produced by silver reduction of silver bromide. It is a method to do. Various sensors have also been developed for detecting the concentration of hydrogen gas present in the atmosphere.

  In addition to the above, several methods have been proposed for hydrogen detection or analysis. For example, Patent Document 1 discloses a method for visualizing the hydrogen distribution on the surface of a solid material. Specifically, the surface of the solid material on which hydrogen is adsorbed or occluded is brought into contact with a silver ammonium nitrate aqueous solution, thereby silver ammonium nitrate. In this method, silver ions in an aqueous solution are reduced to silver by hydrogen adsorbed or occluded on the surface of the solid material, and precipitated on the surface of the solid material for visualization. Since this method does not use a harmful reagent such as a cyanide, the preparation of the visualization reagent and the safety of the visualization operation are high, and problems such as waste liquid treatment do not occur.

  Further, Patent Document 2 discloses a method of detecting leakage of hydrogen by a change in electric resistance by utilizing an increase in electric resistance generated when platinum is eroded by hydrogen at a high temperature. In this method, phosphorus and phosphorous oxide are coexisted with platinum in order to promote erosion by hydrogen and increase the speed of detection response. Specifically, a detection unit made of platinum is accommodated in a stainless steel pipe, and a powder of phosphorus or phosphor oxide is mixed with alumina cement to fill a gap between the platinum detection unit and the stainless steel pipe to form a packed layer, and the detection unit In this method, a method is adopted in which a wire made of an alumina sintered body is wound so that the platinum fine wires do not come into contact with each other, and a conductive wire is connected to both ends of the platinum fine wire to measure the electrical resistance.

Further, in Patent Document 3, a voltage is applied between cell-type electrodes of a fuel cell, a permeated hydrogen gas is supplied to the anode side, and air is supplied to the cathode side. A method for measuring the amount of permeating hydrogen gas is disclosed, and Patent Document 4 provides a hydrogen dissociation catalyst electrode on one surface of an electrolyte membrane having hydrogen ion conductivity, and a hydrogen generation catalyst electrode on the other surface. A positive current collector plate provided with a flow path that opens to a gas pipe through which a gas to be detected flows is provided on the surface of the hydrogen dissociation catalyst electrode, and a hydrogen generation catalyst electrode is provided on the surface of the hydrogen generation catalyst electrode. A negative electrode current collector plate that is directly exposed to the detection gas is disposed, a DC voltage is applied between the current collector plates, and the negative ion current collector plate is fed from the flow path by the hydrogen ion transport action from the hydrogen dissociation catalyst electrode toward the hydrogen generation catalyst electrode. Detected gas Method for detecting a current that varies depending on the concentration of the hydrogen gas is disclosed.
Japanese Patent No. 3428771 JP-A-62-271306 JP-A-57-84511 JP 2002-117734 A

  However, among the above methods, the method using tritium autoradiography can observe the location of hydrogen at the metal structure level, but is not a simple method because it uses tritium, which is a radioisotope. Moreover, according to ion mass spectrometry, the hydrogen distribution state in the horizontal direction and depth direction of the material can be known, and hydrogen on the surface of the material can be accurately observed by the silver decoration method and the microprint method.

  However, these methods are effective as a method for analyzing hydrogen existing in a minute region, but the existence state and leakage of hydrogen existing in a wide region are observed, or the hydrogen existing state in a macro region of about several tens of centimeters or more. It is not suitable for the observation and analysis of hydrogen and the confirmation of hydrogen gas leak position. The techniques disclosed in the above-mentioned Patent Documents 1 to 4 are essentially the same in that they are not suitable methods for detecting a hydrogen distribution in a relatively wide site or specifying a hydrogen leak site.

  In addition, it is not possible to know the hydrogen storage site or leakage site in a material by using a temperature rising analysis method such as API-MS or an electrochemical permeation method. Moreover, none of the methods described above is an easy method because it requires expensive equipment and equipment, and visual observation with the naked eye is difficult.

  The present invention has been made in view of the prior art as described above, and an object of the present invention is to easily and reliably visually detect hydrogen gas (more specifically, leaked hydrogen gas) existing in a relatively wide observation region. It is to provide a technique that can be detected.

  The hydrogen gas detection material of the present invention that has been able to solve the above-mentioned problem is that a water retention support material is loaded with a dye having a chromophore that undergoes hydrogen reduction and decolorization, and a hydrogenation catalyst. It is characterized in that is carried.

In the dye as the main component of the hydrogen gas detection material according to the present invention, a preferred chromophore that undergoes hydrogen reduction is at least selected from the group consisting of an azo group, a nitro group, a nitroso group, a carbonyl group, and an ethylene group. As the hydrogenation catalyst, at least one selected from the group consisting of Pd, Ni, Ru, and Pt (particularly preferable is Pd and Pt) is preferably used. A preferable loading amount of the hydrogenation catalyst with respect to the supporting material is 0.005 mg / cm ² or more and 10 mg / cm ² or less, more preferably 0.01 mg / cm ² or more and 0.5 mg / cm ² or less.

  The carrier is preferably a hydrogen gas-permeable flat cloth or tape-like material, and a temporary fixing adhesive is attached to a part of one surface.

  The hydrogen gas detection member of the present invention is characterized in that the hydrogen gas detection material having the above-described configuration is provided in the hydrogen gas detection unit. Furthermore, in the hydrogen gas leak detection method of the present invention, the detection member is disposed at a site where hydrogen gas leak is a concern, and the hydrogen gas leak is detected by the disappearance of the color derived from the dye contained in the detection member. It has the characteristics.

  The hydrogen gas detection material of the present invention comprises a water-holding support material as described above, and a dye having a chromophore that undergoes decolorization upon hydrogen reduction and a hydrogenation catalyst, preferably further a pH adjusting component. However, when the detection material comes into contact with hydrogen gas, the dye contained therein undergoes hydrogen reduction and decolorizes immediately. For this reason, if the detection material is arranged at a site where the leakage of hydrogen gas is a concern, for example, the leakage of hydrogen gas can be easily and reliably detected with the naked eye.

  As is well known, hydrogen gas is chemically extremely active at high temperatures and reacts with various compounds. A typical example is a hydrogenation reaction, and hydrogenation of a compound having an unsaturated double bond is used in various fields. However, hydrogen activity at room temperature is low, and reaction with other compounds hardly occurs. Absent. However, when a hydrogenation catalyst such as Pt or Pd is used, it can react even at room temperature.

  On the other hand, most of the dyes are colored by the bias of charge due to the movement of π electrons in the chromophore having a conjugated double bond and the absorption of light of various wavelengths accompanying it. It is widely used as a means. It is also known that when a double bond in a colored dye is hydrogenated, it loses its original color and decolorizes. However, even if measures to prevent such decolorization and fading of dyes are taken as undesirable phenomena that degrade the original characteristics of the dyes, there is almost no technical idea to actively utilize decolorization and fading. As far as the inventors know, there is no technical idea of utilizing such decolorization and fading of dyes for detection of hydrogen gas.

  By the way, in order to build a fuel cell utilization system that has been attracting attention recently, in order to ensure safety associated with the use of hydrogen gas used as the fuel, leakage of hydrogen gas from equipment is prevented, Alternatively, the leak detection technology is necessarily required, and establishment of a technology that can easily and reliably detect hydrogen gas at a macro level is desired.

  Under these circumstances, the present inventors thought that the decolorization phenomenon of the above-mentioned dye by hydrogen gas could be utilized for detection of the hydrogen gas at the macro level, which has not been attracting much attention so far. I have been researching along the way. As a result, if a dye having a chromophore that undergoes hydrogen reduction and decolorization and a hydrogenation catalyst are supported on a water-retaining material, the hydrogen gas can easily react with the dye even at room temperature due to the action of the hydrogenation catalyst. Then, the chromophore in the dye was reduced with hydrogen, and the original color of the dye was lost. By the decolorization, it was found that the presence of hydrogen gas could be easily detected with the naked eye.

  Accordingly, the dye used in the present invention has a chromophore that undergoes decolorization upon hydrogen reduction, and examples of the chromophore include azo group, nitro group, nitroso group, carbonyl group, ethylene group, thiocarbonyl group, carbimino group. Group and the like. Ordinary dyes have a polycyclic aromatic skeleton having a plurality of benzene rings or naphthalene rings, and these rings and rings are connected by an azo group or an ethylene group, or the terminal ring. A structure having a nitro group, a nitroso group, a carbonyl group or the like bonded exhibits remarkable color development.

  The dyes having such a molecular structure include phenol red, phenolphthalein, bromophenol blue, thymol blue, methyl yellow, methyl orange, methyl red, bromothymol blue, thymolphthalein, alizarin yellow, congo red, bromocresol purple, bromocresol. Examples include green, amide black, and Evans blue, but of course not limited thereto. These dyes may be used alone or in combination of two or more in any combination.

For example, an azo group (—N═N—), a nitro group (—NO ₂ ), an ethylene group (—C═C—), etc. contained in the dye are each —NH—NH—, when hydrogenated. It changes to —NH ₂ , —CH ₂ —CH ₂ — to lose its function as a chromophore and lose its color. The same applies to the nitroso group and the carbonyl group, and the structure is changed by hydrogenation and the function as a chromophore is lost.

  Such a hydrogenation reaction does not proceed in a room temperature atmosphere even if a considerable amount of hydrogen gas is present. However, if a hydrogenation catalyst is allowed to coexist with the dye, the hydrogenation reaction proceeds at room temperature, and a chromophore is formed. Change and lose the dye's own color. As the hydrogenation catalyst used here, metal powders such as Pd, Ni, Ru, and Pt are effective, and these metals can be used alone or in combination of two or more in any combination. Good. Among these, Pt and Pd having a high hydrogenation catalytic action are particularly preferable, and Pd is particularly preferable because it allows the hydrogenation reaction to proceed reliably without heating or pressurization.

  The hydrogen gas detection material of the present invention is produced by supporting the dye and the hydrogenation catalyst on a water retention material. The water-retaining material is not particularly limited as long as it can disperse and carry the dye and the hydrogenation catalyst powder in a uniform distribution state. Cellulosic natural fibers including paper typified by filter paper or Nonwoven fabrics and woven / knitted fabrics made of various synthetic fibers such as recycled fibers, polyester fibers, vinylon fibers, acrylic fibers, polyamide fibers, and films made of water-absorbing polymers can also be used.

  As a method of supporting a dye or a hydrogenation catalyst on these support materials, a method of kneading a dye or a hydrogenation catalyst powder into the above-mentioned support material and processing it into a fiber shape or a film shape, a fiber in a non-woven shape, woven / woven What is necessary is just to employ | adopt the method of attaching dye and hydrogenation catalyst powder by methods, such as application | coating and impregnation, after processing into a knitted form etc. or processing a water retention polymer into a film form. It is preferable to use a support material that is permeable to hydrogen gas and light in color such as white so that decolorization due to hydrogen detection can be detected more quickly with the naked eye. Also, the carrier material should be a hydrogen gas permeable flat cloth (label) or tape, and if a temporary adhesive is attached to a part of one side, it can be attached or wrapped around the object to be inspected. Convenient for use.

  When a water-retaining polymer is used as a support material, a dye and a hydrogenation catalyst fine powder are dispersed in an aqueous liquid of the polymer, and a brush or spray is applied to the hydrogen gas detection site in the form of a paint. It can also be used for hydrogen gas detection in the form of a coating film. Typical examples of the water-retaining polymer include sodium polyacrylate and carboxymethyl cellulose.

The preferable amount of the dye attached to the support material varies depending on the type of the dye and cannot be determined uniformly, but is preferably 0.001 to 1 mg / cm ² per detection effective surface area of the detection material, more preferably The range is 0.005 to 0.1 mg / cm ² . By the way, if the amount of dye attached is too small, the color in the colored state will be thin and the visibility will be poor, making it difficult to detect decolorization with the naked eye. Thus, the detection time is deteriorated.

Further, the amount of supported hydrogenation catalysts will vary depending on the type and the kind of dye used in the catalyst, a standard amount of supported 0.005~10mg / cm ^2, more preferably 0.01 to 1 mg / ^cm 2, More preferably, it is the range of 0.01-0.5 mg / cm < ² >. Incidentally, if the amount of the catalyst supported is insufficient, the progress of the hydrogenation reaction is delayed, and the accuracy and speed of detection are impaired. From the viewpoint of detection accuracy and rapidity, there is no upper limit on the amount of catalyst supported. However, if it is too much, the effect is not increased any more, and the cost is unnecessarily high, which is economically wasteful. The hydrogenation catalyst is normally supported on the support material as fine powder having a particle size of about 0.1 mm or less. However, when it is supported on a thin support material, a sputtering method or the like is used on one side of the thin support material. It is also possible to carry it in the form of a thin film.

  In order to detect hydrogen gas accurately and quickly, it is preferable that the catalyst enters not only the surface of the support material but also the interior of the support material and is in three-dimensional contact with the dye. Therefore, in order to efficiently detect the hydrogen gas when the hydrogenation catalyst is supported by the sputtering method, the catalyst on one side of the support material is formed into a thin film and then swollen with water, and then from the surface where the film is not formed. A method of sucking or a method of laminating several layers of a thin film-like support material having a thickness of about 0.1 mm or less on which a catalyst is supported in a thin film form by sputtering is sufficient.

  In many dyes, the color tone and intensity of color change depending on the pH of the aqueous solution, so that the optimum color tone and color intensity can be obtained according to the base color of the site to be detected. It may be adjusted, and depending on the detection site of hydrogen gas, it may be deteriorated by acid or alkali. Therefore, pH adjustment may be required in order to prevent such deterioration. For this reason, in the present invention, it is preferable to support a pH adjusting component in addition to the dye and the hydrogenation catalyst so that an optimum color development state corresponding to the application and purpose can be obtained. In addition to normal acids (hydrochloric acid, sulfuric acid, formic acid, acetic acid, etc.) and alkalis (alkali metal and alkaline earth metal hydroxides and carbonates, etc.), the pH adjusting component used here is phosphate and It is preferable to use a salt having a buffering action such as a first and second phosphate so that a stable color development state can be obtained in a stable pH range. In addition, when securing the pH in the neutral range, neutral water (including deionized water and distilled water) can also be a pH adjusting component.

  The reason why the water retaining material is selected as the support material used in the present invention is as follows. That is, as described above, most of the dyes have different colors and strengths depending on the pH, and there is an optimum pH that shows the most easily observed color development state. For this reason, it is preferable to use a water-retaining support material in order to make more effective use of the characteristics of these dyes and enable a more vivid color development state and decolorization by hydrogenation to be observed with the naked eye.

  There is no restriction | limiting in particular in the shape of the hydrogen gas detection material which concerns on this invention, According to the place where hydrogen gas detection is performed, it can be set as the thing of arbitrary shapes, such as label shape, a flat cloth shape, ribbon shape, and tape shape. . For example, if you want to detect hydrogen leakage at a relatively wide joint in a hydrogen container, you can use a relatively wide flat cloth, and if the location to be detected is limited to a limited narrow position, label Or a flat cloth shape with a narrow width. When hydrogen gas leakage from a tubular part such as a hydrogen pipe is to be detected, it may be formed in a long ribbon shape or tape shape so that it can be used by being wound around a portion to be detected. In this case, it is also effective to attach an adhesive or the like to a part of the cloth-like or tape-like detection material so that it can be easily temporarily fixed to the detection location.

  In addition, a water-soluble polymer or water-retaining polymer is used as a support material, and dyes or hydrogenation catalysts are dissolved or dispersed in it as a paint-type detection material. It is also possible to detect a gas leak by applying and forming a film by any method such as spray coating. In such a usage form, the water-soluble polymer functions as a support material. Such a coating type detection agent is preferable because it can be applied without difficulty to parts having complicated shapes. It is also possible to apply a liquid detection agent containing a dye, a hydrogenation catalyst, a suitable binder and the like to one side of paper or fabric of any size.

  Thus, according to the present invention, based on the new idea of utilizing the decolorization of the chromophores contained in the dye molecules by hydrogen reduction for detection of hydrogen gas, the hydrogen gas in particular in the hydrogen gas utilization equipment or hydrogen gas piping is used. The leak can be reliably detected with a simple operation, and a hydrogen gas explosion accident, which is a concern about the leak of hydrogen gas, can be prevented. Therefore, future effective utilization is expected as part of safety management of infrastructure equipment required for fuel cell vehicles and air conditioning facilities using fuel cell power generation that are expected to be put to practical use in the near future.

  Hereinafter, the present invention will be described more specifically with reference to experimental examples.However, the present invention is not limited by the following experimental examples, but may be appropriately modified within a range that can meet the purpose described above and below. It is also possible to implement, and they are all included in the technical scope of the present invention.

Experimental example 1
A predetermined amount of a dye solution and a hydrogenation catalyst shown in Table 1 below are supported on a filter paper having a thickness of 0.3 mm, and a hydrogen gas detection experimental instrument schematically shown in FIG. 1 (in the figure, 1 is a hydrogen gas detection material, 1a is a dye-impregnated filter paper, 1b is a hydrogenation catalyst support layer, 2 is a glass tube, 3 is silicon rubber, 4a and 4b are hydrogen gas conduits, respectively, and humidified hydrogen gas (nitrogen gas and Or 50/50 vol% mixed gas) or air was allowed to flow at a flow rate of 5 ml / min. Then, each hydrogen gas detection material shown in Table 1 was mounted on a detection experimental instrument, gas was allowed to flow under the above conditions, and the color change of the dye-impregnated filter paper after maintaining for a predetermined time was visually observed.

  The results are as shown in Table 1. In the case of reference numerals 1 to 8 in which a dye having an appropriate chromophore and a hydrogenation catalyst were combined, the color of the dye immediately disappeared due to the inflow of hydrogen gas. On the other hand, in the code | symbols 9 and 10 which did not carry | support a hydrogenation catalyst, and the code | symbol 11 which flowed air as gas, the color change by a dye was not recognized.

Experimental example 2
As shown in FIG. 2, one end of a stainless steel tube 5 (inner diameter 30 mm) having one pin hole 6 having a diameter of 0.5 mm is sealed with a silicone rubber plug 3, and hydrogen gas conduits 4a and 4b are provided on the opposite side. A penetrating silicon rubber stopper is arranged, and a ribbon-shaped filter paper 7 is wound around the outer periphery of the stainless steel pipe 5.

The ribbon-shaped filter paper 7 is preliminarily supported with 0.5 mg / cm ² of Pd powder on one side and sprayed with an aqueous solution of methyl red (0.5 mg / ml) adjusted to be acidic with hydrochloric acid. The sample was dyed red. Then, when hydrogen gas was flowed through the hydrogen gas conduits 4a and 4b at a flow rate of 100 ml / min, after about 10 minutes, the pigment was decolorized in the form of white spots at the pinhole 6 position, and the hydrogen leaking point was detected with the naked eye. We were able to.

  On the other hand, nothing is carried on the ribbon-shaped filter paper 7, and Pb powder is dispersed in the same methyl red aqueous solution as described above so as to be 0.05 mg / ml, and this dye + catalyst dispersion is sprayed on the filter paper 7. Applied. Then, when hydrogen gas was flowed through the hydrogen gas conduits 4a and 4b at a flow rate of 100 ml / min in the same manner as described above, decolorization of the pigment occurred in the form of white spots at the position of the pinhole 6 after about 15 minutes, and the hydrogen leaking portion Was detected with the naked eye.

Experimental example 3
A hydrogenation catalyst (Pd black powder) is supported on a 0.3 mm thick filter paper by changing the amount by suction filtration, and then impregnated with a red aqueous solution of methyl red (0.5 mg / ml). It was set in the experimental apparatus schematically shown in No. 1 and was exposed to hydrogen by flowing a humidified hydrogen gas from a hydrogen conduit at a flow rate of 5 ml / min. Using a color difference meter (trade name “CR-200” manufactured by Minolta Co., Ltd.), the L ^* value, a ^* value, and b ^* value before hydrogen exposure were measured with a C light source, and L was exposed to hydrogen for a predetermined time. ^{The *} value, a ^* value, and b ^* value were determined. Then, from the difference between each L ^* value, a ^* value, and b ^* value (ΔL ^* value, Δa ^* value, Δb ^* value) before and after the hydrogen exposure, the degree of color change (color difference: ΔE ^* ab) before and after the hydrogen exposure. ) Was determined by the following color difference calculation formula described in JIS-Z-8730, and the color change rate per unit time (ΔE ^* ab / min) was determined from the hydrogen exposure time.
Color difference (ΔE ^* ab) = [(L ^* ) ² + (Δa ^* ) ² + (Δb ^* ) ² ] ^1/2 (JIS-Z-8730)

The relationship between color difference and sensation is evaluated in NBS units (US National Bureau of Standards) as shown in Table 2 below. The greater the color difference value, the greater the color change, and the greater the ΔE ^* ab / min value, the color change rate. Represents fast.

FIG. 3 is a graph showing the relationship between the amount of Pd black powder supported and the color change rate. When the color change rate is 5 or more, the color change or decoloration can be visually confirmed within a few minutes. The supported amount of the hydrogenation catalyst is preferably 0.01 mg / cm ² or more. On the other hand, even if the supported amount exceeds 0.5 mg / cm ² , the color change rate (ΔE ^* ab / min) hardly increases. Therefore, considering the cost, it is determined that the catalyst loading is preferably in the range of 0.01 to 0.5 mg / cm ² .

Experimental Example 4
Using an RF sputtering apparatus, Pd thin films each having a thickness of 50 nm were formed on cellulose filter paper having a thickness of 0.4 mm (Whatman No. 3) and 0.1 mm (Whatman No. 50). Deposition conditions are: target; Pd metal, substrate temperature; room temperature, Ar gas pressure; 1 to 3 mTorr, distance between electrodes; 55 mm, film formation speed; 20 nm / min, ultimate vacuum before film formation; 1.0 × 10 ⁻⁵ Torr, and the loading was about 0.06 mg / cm ² from the specific gravity of Pd.

  A 0.4 mm thick filter paper carrying a hydrogenation catalyst supported by sputtering (reference numeral 16 in Table 3), a catalyst supported on a 0.4 mm thick filter paper, then swollen in pure water, and then supported by the catalyst. What was sucked from the non-permitted surface (reference numeral 17 in Table 3), filter paper having a thickness of 0.1 mm (reference numeral 18 in Table 3), and a laminate of three filter papers having a thickness of 0.1 mm (in Table 3) 19) is impregnated with a red-colored methyl red aqueous solution (0.5 mg / ml), set in the experimental apparatus schematically shown in FIG. 1, and humidified hydrogen gas from a hydrogen conduit at a flow rate of 5 ml / min. Flowed and exposed to hydrogen. Then, the color change of the dye-impregnated filter paper was observed with the naked eye, and the time until the dye color disappeared was measured. Incidentally, in the sample of reference numeral 14, the filter paper was thin, so that the initial color was a pink color lighter than red.

  The results are as shown in Table 3, and even if the catalyst is supported only by the sputtering method, the color disappears due to the hydrogen exposure. However, by adding a device for supporting the catalyst inside the supporting material, the detection can be quickly performed. The sex can be further enhanced.

It is explanatory drawing of the hydrogen gas detection apparatus used in experiment. It is explanatory drawing of the other hydrogen gas detection apparatus used in experiment. It is a graph which shows the relationship between the amount of Pd black carried and the color change rate (ΔE ^* ab / min).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hydrogen gas detection material 1a Dye impregnated filter paper 1b Hydrogenation catalyst support layer 2 Glass tube 3 Silicon rubber 4a, 4b Hydrogen gas conduit 5 Stainless steel tube 6 Pinhole 7 Ribbon filter paper

Claims (8)

The water-retaining support material carries a dye having a chromophore that undergoes hydrogen reduction and decolorization and a hydrogenation catalyst, and the chromophore is at least one selected from the group consisting of an azo group, a nitro group, and a carbonyl group. A hydrogen gas detection material characterized by having a seed .   The hydrogen gas detection material according to claim 1, further comprising a pH adjusting component. The hydrogen gas detection material according to claim 1 or 2 , wherein the hydrogenation catalyst is at least one selected from the group consisting of Pd, Ni, Ru, and Pt. The hydrogen gas detection material according to claim 1 or 2, wherein the hydrogenation catalyst is at least one selected from the group consisting of Pd and Pt. Hydrogen gas detecting material according to claim 3 or 4 supported amount of the hydrogenation catalyst is 0.005~10mg / cm ² with respect to the support material.   The hydrogen gas detection according to claim 1, wherein the support material is a hydrogen gas permeable flat cloth or tape-like material, and an adhesive for temporary fixing is attached to a part of one side. Wood.   A hydrogen gas detection member, wherein the hydrogen gas detection material according to any one of claims 1 to 6 is disposed in a hydrogen gas detection unit.   The detection member according to claim 7 is arranged at a site where leakage of hydrogen gas is a concern, and it is confirmed that hydrogen gas has leaked due to the disappearance of the color derived from the dye contained in the detection member. Hydrogen gas leak detection method.

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