JP2016153732A - Moisture content detection unit, and moisture content detection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a moisture content detection unit with which it is possible to improve the reliability of sensitivity of detecting a moisture content included in a gas.SOLUTION: The moisture content detection unit includes a moisture detection part 23 including a porous metal complex layer 23-2 that comprises a filter 23-1 having light permeability and a porous metal complex covering one surface 23-1a of the filter 23-1, to which is supplied a gas containing moisture. The porous metal complex contains a metal and an organic ligand coordinated with the metal, the organic ligand including a structure of one of trimesic acid, terephthalic acid, imidazole, 1,3,5-tris(4-carboxyphenyl)benzene, 1,2,4,5-tetrakis(4-carboxyphenyl)benzene, and 2-hydroxyterephthalic acid.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a moisture concentration detection unit for detecting moisture contained in a gas, and a moisture concentration detection method using the moisture concentration detection unit.

Generally, in the manufacturing process of industrial gases such as nitrogen and argon, it is important to manage the purity of the industrial gas in order to ensure the quality of the industrial gas.
Industrial gases such as nitrogen and argon are produced by a rectification separation process using dry air as a raw material. For this reason, conventionally, for the purpose of monitoring defects in the manufacturing process, the concentration of water contained in the manufactured industrial gas has been measured.
Further, in the product industrial gas after rectification separation, impurities such as moisture may be mixed from the outside air. Therefore, it is extremely important to monitor the concentration of moisture in managing the purity of the gas.

For example, in a semiconductor device manufacturing apparatus that manufactures semiconductor devices, a replacement process using a large amount of inert gas is required to remove moisture remaining in the process system.
During the replacement process, it is possible to prevent waste of excess inert gas by appropriately managing the water concentration in the process system.

As a conventional humidity detection sensor, for example, there is a humidity detection sensor (capacitance sensor) disclosed in Patent Document 1.
In Patent Document 1, a sensor body composed of a pair of electrodes and a polymer film disposed between the pair of electrodes is disposed on one surface of a substrate having at least one through-hole penetrating the substrate in the thickness direction. A humidity detection sensor is disclosed.
Patent Document 1 discloses that a conductive material such as a metal is used as the material for the pair of electrodes, and an organic polymer material having electrical insulation and wet / dry characteristics is used as the material for the polymer film. ing.

JP 2002-328110 A

    However, since the humidity detection sensor disclosed in Patent Document 1 uses a highly hygroscopic polymer film, for example, a sample is changed from a high concentration (for example, 100 ppm or more) moisture-containing gas to a low concentration (for example, 10 ppb). In the case of switching to the moisture-containing gas described below, it was difficult to quickly desorb the high-concentration moisture adsorbed on the sensor body.

  For this reason, it takes a long time for the indicated value of the humidity detection sensor to become a value corresponding to the moisture concentration of the moisture-containing gas currently being measured (in other words, because the response speed is slow). There was a problem that the reliability of density detection sensitivity was lowered.

  Therefore, an object of the present invention is to provide a moisture concentration detection unit and a moisture concentration detection method capable of improving the reliability of detection sensitivity of moisture concentration contained in gas.

  In order to solve the above-mentioned problem, according to the first aspect of the present invention, there is provided a moisture concentration detection unit for detecting the concentration of moisture contained in a gas, and covers a light-transmitting filter and one surface of the filter. Irradiate light of a specific wavelength onto one surface of the porous metal complex layer located on the opposite side of the surface that contacts the one surface of the filter and the surface of the filter that includes a porous metal complex layer made of a porous metal complex. A light source, a gas supply path for supplying the gas to one surface of the porous metal complex layer, and the moisture detection unit are arranged to face the light source, irradiated from the light source, and A light-receiving unit that receives the transmitted light that has passed through the moisture detection unit and generates a voltage corresponding to the intensity of the transmitted light; and a voltage-measuring unit that measures the voltage. And coordinate bond with the metal It comprises an organic ligand, wherein the organic ligand, water concentration detection unit is provided, which comprises any of the structures represented by the following general formula (1) to (6).

  Moreover, according to the invention which concerns on Claim 2, the said metal is Cu or Co, The moisture concentration detection unit of Claim 1 characterized by the above-mentioned is provided.

  According to the invention of claim 3, the moisture concentration detection unit according to claim 1 or 2, wherein the porous metal complex is copper benzene-1,3,5-tricarboxylate. Provided.

  Moreover, according to the invention which concerns on Claim 4, the wavelength of the said light irradiated from the said light source is 350 nm or more and 650 nm or less, The moisture of any one of Claims 1 thru | or 3 characterized by the above-mentioned. A concentration detection unit is provided.

  Moreover, according to the invention which concerns on Claim 5, it is a moisture concentration detection method using the moisture concentration detection unit of any one of Claims 1 thru | or 4, Comprising: The said light source is used, The said porosity A step of irradiating one surface of the metal complex layer with the light of the specific wavelength, and a step of supplying the gas containing moisture to the one surface of the porous metal complex layer in a state where the irradiation of the light is continued. A step of receiving the transmitted light transmitted through the moisture detection unit out of the light of the specific wavelength by the light receiving unit, and generating a voltage according to the intensity of the transmitted light, and the voltage measuring unit And a step of measuring the voltage.

  ADVANTAGE OF THE INVENTION According to this invention, the reliability of the detection sensitivity of the moisture concentration contained in gas can be improved.

It is sectional drawing which shows schematic structure of the moisture concentration detection unit which concerns on embodiment of this invention. It is a graph of the calibration curve which shows the relationship between the moisture concentration contained in sample gas, and the voltage output value of a light-receiving part. It is a graph which shows the relationship between the elapsed time from the supply start of gas, and the voltage output value of a light-receiving part. It is a graph which shows the relationship between the wavelength of the light irradiated to a porous metal complex layer, and the voltage output value of a light-receiving part.

  Embodiments to which the present invention is applied will be described below in detail with reference to the drawings. The drawings used in the following description are for explaining the configuration of the embodiment of the present invention, and the size, thickness, dimensions, etc. of each part shown in the figure are the dimensional relationships of the actual moisture concentration detection unit. May be different.

(Embodiment)
FIG. 1 is a cross-sectional view showing a schematic configuration of a moisture concentration detection unit according to an embodiment of the present invention.
Referring to FIG. 1, a moisture concentration detection unit 10 of the present embodiment includes a light source 11, a light source position regulating member 13, a power source 14, a first optical fiber 16, a gas path built-in member 18, and a gas. A supply pipe 21, a moisture detector 23, a seal member 24, a moisture detector fixing member 26, a second optical fiber 28, a light receiver fixing member 31, a light receiver 33, a voltage measuring unit 35, A water concentration calculation unit 36.

The light source 11 irradiates the moisture detection unit 23 with light having a specific wavelength via the first optical fiber 16. As the light source 11, a light source having a variable wavelength of light to be irradiated may be used. As the light source 11, for example, an LED lamp can be used.
For example, when copper benzene-1,3,5-tricarboxylate is used as the material of the porous metal complex layer 23-2, the wavelength of light emitted from the light source 11 (specific wavelength) is, for example, 350 nm or more and 650 nm or less. It is better to be within the range.

When the wavelength of the light emitted from the light source 11 is less than 350 nm, it is difficult to generate a voltage when the light receiving unit 33 receives the intensity of the transmitted light that is emitted from the light source 11 and transmitted through the moisture detection unit 23. there is a possibility.
Further, when the wavelength of light emitted from the light source 11 becomes larger than 650 nm, it is difficult to generate a voltage when the light receiving unit 33 receives the intensity of transmitted light that is emitted from the light source 11 and transmitted through the moisture detecting unit 23. There is a possibility.
Accordingly, by setting the wavelength of the light emitted from the light source 11 within the range of 350 nm to 650 nm, for example, the light receiving unit 33 can output a voltage corresponding to the intensity of the transmitted light. The moisture concentration contained in the gas can be calculated using the voltage value (voltage output value) output by 33.

  Moreover, when using the said copper benzene-1,3,5-tricarboxylate, as for the wavelength of the light which the light source 11 irradiates, 450 nm or more and 550 nm or less are more preferable, for example. By setting the wavelength of the light emitted from the light source 11 within the range of 450 nm or more and 550 nm or less, the moisture concentration contained in the gas can be calculated with higher accuracy.

The light source position restricting member 13 is disposed below the other end 16 </ b> B of the first optical fiber 16. The light source position restricting member 13 fixes the other end 16 </ b> B of the first optical fiber 16 via a fixing bracket (not shown).
The light source position restricting member 13 has a penetrating portion 13 </ b> A corresponding to the outer shape of the light source 11. The penetrating portion 13 </ b> A is provided at the center of the light source position regulating member 13. 13 A of penetration parts are regulating the position of the light source 11 in the state in which the light source 11 can irradiate the moisture detection part 23 with the light of a specific wavelength. The light source 11 is fixed to the penetrating portion 13 </ b> A of the light source position regulating member 13.
The power source 14 is electrically connected to the plus terminal 11A and the minus terminal 11B of the light source 11. When power is supplied from the power source 14, the light source 11 emits light of a specific wavelength.

The first optical fiber 16 is arranged so that one end 16 </ b> A faces the one surface 23-2 a of the porous metal complex layer 23-2 constituting the moisture detection unit 23, and the other end 16 </ b> B faces the light source 11. Is arranged.
The first optical fiber 16 extends in a predetermined direction (a direction from the moisture detection unit 23 toward the light source 11). The first optical fiber 16 has a first portion 38 and a second portion 39. The first and second portions 38 and 39 extend in the same direction as the extending direction of the first optical fiber 16.

The 1st part 38 is comprised only by the core part 16-1 made into the column shape. The first portion 38 is disposed in the insertion hole 42 provided in the extending direction of the first optical fiber 16 and the porous metal complex layer exposed portion 45.
The 2nd part 39 is comprised by the core part 16-1 and the clad part 16-2 which covers the side surface of the core part 16-1. A part of the second portion 39 is disposed in the insertion hole 42, and the remaining portion is disposed below the gas path built-in member 18. The core part 16-1 which comprises the 1st and 2nd parts 38 and 39 is united.

One end 16A of the first optical fiber 16 is composed of only the core portion 16-1, and the other end 16B of the first optical fiber 16 is composed of the core portion 16-1 and the cladding portion 16-2. Yes.
One end 16 </ b> A of the first optical fiber 16 is flush with the upper surface of the gas path built-in member 18. The core portion 16-1 constituting the other end 16 </ b> B of the first optical fiber 16 is disposed so as to face the light source 11.
The clad portion 16-2 constituting the other end 16 </ b> B of the first optical fiber 16 is fixed to the upper surface of the light source position regulating member 13.

The core portion 16-1 constituting the first optical fiber 16 transmits light of a specific wavelength irradiated by the light source 11, and irradiates the surface 23-2a of the porous metal complex layer 23-2 with the transmitted light. To do.
The diameter of the core part 16-1 which comprises the 1st optical fiber 16 can be suitably set within the range of 0.5 mm-3 mm, for example. In this case, the thickness of the cladding part 16-2 can be appropriately set within a range of 1 mm to 3 mm, for example.

  As described above, the first end 16A is disposed so as to face the one surface 23-2a of the porous metal complex layer 23-2 constituting the moisture detection unit 23, and the other end 16B is disposed so as to face the light source 11. By providing the one optical fiber 16, the light irradiated by the light source 11 can be efficiently irradiated onto the one surface 23-2a of the porous metal complex layer 23-2.

The gas path built-in member 18 includes a member main body 41, an insertion hole 42, a gas supply path 43, a porous metal complex layer exposed portion 45, and a gas discharge path 46.
The member body 41 is a columnar member. On one surface of the member main body 41, the moisture detection unit 23 is disposed via the seal member 24. As a material of the member main body 41, for example, stainless steel or the like can be used.

The insertion hole 42 is a hole arranged so as to extend from the lower end side of the member main body 41 to the center of the member main body 41. One end of the insertion hole 42 is exposed from the lower end of the member main body 41.
The insertion hole 42 extends in the same direction as the extending direction of the first optical fiber 16. Part of the first and second portions 38 and 39 is inserted into the insertion hole 42. The insertion hole 42 restricts the position of the second portion 39. The diameter of the insertion hole 42 can be configured to be equal to the diameter of the second portion 39, for example.

The gas supply path 43 passes through the lower part of the member main body 41 located outside the insertion hole 42 and is disposed so as to intersect the insertion hole 42. The gas supply path 43 is integrated with the insertion hole 42. The gas supply path 43 exposes the first portion 38 of the first optical fiber 16 inserted into the insertion hole 42 (in other words, the core portion 16-1 having a diameter smaller than that of the insertion hole 42). ing.
A gas containing moisture is supplied to the gas supply path 43. The gas supplied to the gas supply path 43 is supplied to the one surface 23-2a of the porous metal complex layer 23-2 by being guided in the extending direction of the first portion 38.

The porous metal complex layer exposed portion 45 is a recess provided so as to penetrate the member main body 41 located on the insertion hole 42. The upper end of the porous metal complex layer exposed portion 45 is exposed from the upper surface of the member main body 41.
The porous metal complex layer exposed portion 45 is configured integrally with the upper end of the insertion hole 42. The porous metal complex layer exposed portion 45 is formed wider than the insertion hole 42. The porous metal complex layer exposed portion 45 is disposed so as to face the one surface 23-2a of the porous metal complex layer 23-2.

The gas discharge path 46 is provided so as to pass through the upper part of the member main body 41 located outside the porous metal complex layer exposed portion 45 and intersect the porous metal complex layer exposed portion 45.
The gas discharge path 46 is integrated with the porous metal complex layer exposed portion 45. The gas discharge path 46 discharges the gas supplied to the one surface 23-2a of the porous metal complex layer 23-2 to the outside of the gas path built-in member 18 through the porous metal complex layer exposed portion 45. This is the route.

The gas supply pipe 21 is a tubular member having a size capable of interposing a gap with the first portion 38. The gas supply pipe 21 is disposed in the insertion portion 42 located above the second portion 39 and the porous metal complex layer exposed portion 45.
The gas supply pipe 21 has substantially the same outer diameter as the insertion hole 42 and is fixed to the insertion portion 42. The gas supply pipe 21 accommodates the first portion 38. The upper end of the gas supply pipe 21 is flush with the upper surface of the member main body 41.

An annular space 51 extending in the extending direction of the first portion 38 is formed between the gas supply pipe 21 and the first portion 38. The gas supply pipe 21 has a notch 21 </ b> A at a portion facing the gas supply path 43.
The cutout portion 21 </ b> A functions as an introduction portion for guiding the gas containing moisture supplied to the gas supply path 43 to the annular space 51. The annular space 51 functions as a path for guiding the gas supplied to the gas supply path 43 to the one surface 23-2a of the porous metal complex layer 23-2.

When the diameter of the first portion 38 is 2 mm, the inner diameter of the gas supply pipe 21 can be set to 3 mm, for example.
As the gas supply pipe 21, for example, a stainless steel tube can be used.

  The moisture detection unit 23 includes a filter 23-1 and a porous metal complex layer 23-2. The moisture detector 23 has one surface 23-2a of the porous metal complex layer 23-2 facing the one end 16A of the first optical fiber 16 and the porous metal complex layer exposed portion 45, and via the seal member 24. It arrange | positions so that it may press on the upper surface of the member main body 41 (in other words, the upper surface of the gas path | route built-in member 18).

The filter 23-1 has one surface 23-1a on which the porous metal complex layer 23-2 is disposed. One surface 23-1a of the filter 23-1 is disposed so as to face the one end 16A of the first optical fiber 16 and the porous metal complex layer exposed portion 45. The filter 23-1 is made of a light transmissive material.
As the filter 23-1, for example, a filter that transmits 20% or more of light having a wavelength of 100 nm to 1000 nm can be used.
As the filter 23-1, for example, a Teflon (registered trademark) mesh can be used.
When a Teflon (registered trademark) mesh is used as the filter 23-1, the thickness of the filter 23-1 can be appropriately set within a range of 0.1 mm to 3 mm, for example.

The porous metal complex layer 23-2 is disposed so as to cover the one surface 23-1a of the filter 23-1. The porous metal complex layer 23-2 is composed of a porous metal complex (hereinafter referred to as “porous metal complex A”).
The porous metal complex A is a metal organic structure (MOF: Metal Organic Frameworks), and includes a metal (hereinafter referred to as “metal B”) and an organic ligand (hereinafter referred to as “organic ligand D”). Including. The metal organic structure has a porous coordination network structure having a high surface area far exceeding that of activated carbon or zeolite by the interaction of metal B and organic ligand D (organic ligand).

Since the metal B and the organic ligand D have a crosslinked structure, they have high gas adsorption / desorption performance. In addition, a gap of several nm to several tens of nm exists in the skeleton formed by the crosslinked structure, and gas molecules are taken into the gap.
Therefore, by using the metal organic structure, it is possible to repeat reversible adsorption / desorption of gas molecules in the gap in a short time.

  The organic ligand D was trimesic acid having a structure represented by the following general formula (7), terephthalic acid having a structure represented by the following general formula (8), and a structure represented by the following general formula (9). Imidazole, 1,3,5-tris (4-carboxyphenyl) benzene having a structure represented by the following general formula (10), 1,2,4,5-tetrakis having a structure represented by the following general formula (11) It is preferable to use any of (4-carboxyphenyl) benzene and 2-hydroxyterephthalic acid having a structure represented by the following general formula (12).

By using the organic ligand D including any one of the structures represented by the above general formulas (7) to (12), a large number of voids are generated in the structure, so that the metal organic structure can easily absorb and desorb moisture. Can be produced.
When terephthalic acid in which two carboxyl groups are coordinated to the benzene ring and tricarboxylic acid in which three carboxyl groups are coordinated are used as the organic ligand D, examples of the metal B include Zn, Cu, Co, Cr, Al, Sc, and Li can be used.

Examples of the metal B that coordinates only to terephthalic acid include Fe, Ni, Zr, and Be.
Examples of the metal B that coordinates only to tricarboxylic acid include Cu, Nd, Sm, Mo, Tm, and Yb.
For example, Cu or Co is preferably used as the metal B. As described above, by using Cu or Co as the metal B, color development due to moisture adsorption / desorption can be made remarkable.

Examples of the metal organic structure to be the porous metal complex A include copper benzene-1,3,5-tricarboxylate (Cu-BTC (Copper Benzene- which is a metal complex in which benzene tricarboxylic acid is coordinated to a copper atom). 1,3,5-Triboxylate)) may be used.
In addition, Co-BTC, which is a metal complex in which benzenetricarboxylic acid is coordinated to a cobalt atom, Fe-BTC, which is a metal complex in which benzenetricarboxylic acid is coordinated to an iron atom, and a metal complex in which benzenetricarboxylic acid is coordinated to a molybten atom Alternatively, Mo-BTC, Cr-TPA (chromium-terephthalic acid) in which terephthalic acid is coordinated to a chromium atom, Cr-TPA in which terephthalic acid is coordinated to a zinc atom may be used.

  The porous metal complex A is characterized by a reaction with water molecules. Since the porous metal complex A rapidly performs reversible adsorption / desorption of water molecules, when the concentration of the water molecules changes, the degree of color development changes significantly according to the amount of the change, and the change in the water concentration Can be detected promptly. For example, in the case of copper benzene-1,3,5-tricarboxylate, the color density of the blue shade changes remarkably.

When copper benzene-1,3,5-tricarboxylate is used as the porous metal complex A (metal organic structure), the thickness of the porous metal complex layer 23-2 is, for example, in the range of 10 μm to 100 μm. Can be selected as appropriate.
When the thickness of the porous metal complex layer 23-2 is less than 10 μm, there is a possibility that the color change with respect to the water concentration is not sensed. If the thickness of the porous metal complex layer 23-2 is larger than 100 μm, light may not be transmitted.
Therefore, by setting the thickness of the porous metal complex layer 23-2 to 10 μm or more and 1000 μm or less, light can be transmitted efficiently.

  The moisture detection unit 23 configured as described above has a concentration of moisture contained in the gas when the gas containing moisture is supplied to the porous metal complex layer 23-2 and light of a specific wavelength is irradiated from the light source 11. The transmitted light of the corresponding intensity is transmitted. The transmitted light is supplied to the second optical fiber 28.

The seal member 24 is a ring-shaped member, and is disposed between the upper surface of the member main body 41 and the one surface 23-2a of the porous metal complex layer 23-2. The seal member 24 is configured such that the gas supplied to the one surface 23-2a of the porous metal complex layer 23-2 leaks from between the upper surface of the member main body 41 and the one surface 23-2a of the porous metal complex layer 23-2. It has a function to prevent.
As the seal member 24, for example, an O-ring (annular packing) can be used.

The moisture detection unit fixing member 26 is a plate-like member having an insertion hole 26A penetrating the center portion. The insertion hole 26 </ b> A has a size substantially equal to the diameter (outer diameter) of the second optical fiber 28.
The moisture detection unit fixing member 26 is disposed above the gas path built-in member 18 so that the insertion hole 26 </ b> A faces the porous metal complex layer exposed portion 45.
The lower surface 26a of the moisture detection unit fixing member 26 is in contact with the other surface 23-1b of the filter 23-1 disposed so as to close the lower end of the insertion hole 26A. The moisture detector 23 is fixed to the lower surface 26 a of the moisture detector fixing member 26. As a material constituting the moisture detector fixing member 26, for example, an ABS resin obtained by copolymerization of acrylitolyl, butadiene, and styrene can be used.

  The second optical fiber 28 is fixed to the moisture detection unit fixing member 26 in a state where the portion located on the one end 28A side is inserted into the insertion hole 26A. One end 28A of the second optical fiber 28 is in contact with the other surface 23-1b of the filter 23-1. The second optical fiber 28 is disposed so as to extend in the same direction as the first optical fiber 16.

The second optical fiber 28 includes a core portion 28-1 and a cladding portion 28-2. One end of the core portion 28-1 is disposed so as to face one end of the core portion 16-1 constituting the first portion 38.
As described above, the moisture detection unit 23 is configured by opposingly arranging one end of the core part 28-1 constituting the second optical fiber 28 and one end of the core part 16-1 constituting the first part 38. Since the transmitted light that has passed through can be efficiently guided to the core portion 28-1, the concentration of moisture contained in the gas can be detected with high accuracy.

Further, from the viewpoint of efficiently guiding transmitted light to the core 28-1, the diameter of the core 28-1 is, for example, the same as the diameter of the core 16-1 constituting the first optical fiber 16. Good.
As the core part 28-1, for example, the same structure as the core part 28-2 constituting the first optical fiber 16 can be used.
The clad portion 28-2 is disposed so as to cover the side surface of the core portion 28-1. As the clad part 28-2, for example, one having the same configuration as the clad part 16-2 constituting the first optical fiber 16 can be used.

The light receiving portion fixing member 31 is a plate-like member having an insertion hole 31A penetrating the center portion. The insertion hole 31 </ b> A has a size substantially equal to the diameter (outer diameter) of the second optical fiber 28.
A portion located on the other end 28B side of the second optical fiber 28 is inserted into the insertion hole 31A. The other end 28 side of the second optical fiber 28 is fixed to the light receiving portion fixing member 31 while being inserted into the insertion hole 31A.
The light receiving portion fixing member 31 is flat and has an upper surface 31a that exposes the upper end of the insertion hole 31A. As a material constituting the light receiving portion fixing member 31, for example, stainless steel can be used.

The light receiving unit 33 is configured to receive the transmitted light that has passed through the core unit 16-1, the moisture detection unit 23, and the core unit 28-1, and closes the upper end of the insertion hole 31A. It is fixed to the upper surface 31a.
Accordingly, the light receiving unit 33 is disposed so as to face the light source 11 via the second optical fiber 28, the moisture detection unit 23, and the first optical fiber 16.
The light receiving unit 33 is electrically connected to the voltage measuring unit 35. The light receiving unit 33 receives the transmitted light transmitted through the moisture detection unit 23, generates a voltage corresponding to the intensity of the transmitted light, and outputs the voltage. For example, a photodiode or a photomultiplier tube can be used as the light receiving unit 33.

The voltage measurement unit 35 is electrically connected to the moisture concentration calculation unit 36. The voltage measuring unit 35 measures the voltage output from the light receiving unit 33 and transmits the measured output voltage value of the light receiving unit 33 to the moisture concentration calculating unit 36.
The moisture concentration calculation unit 36 includes a storage unit (not shown) and a calculation unit (not shown). The storage unit stores data related to a calibration curve (data acquired in advance) indicating the relationship between the moisture concentration contained in the gas and the output voltage value of the light receiving unit 33.
The calculation unit (not shown) calculates the moisture concentration contained in the gas based on the calibration curve and the output voltage value measured by the voltage measurement unit 35. As the moisture concentration calculation unit 36, for example, a personal computer can be used.

The moisture concentration detection unit of the first embodiment includes a porous metal complex layer 23-2 made of a porous metal complex A that covers a light-transmitting filter 23-1 and one surface 23-1a of the filter 23-1. The porous metal complex includes any one of the above-described general formulas (7) to (12) as the metal B and the organic ligand D coordinated with the metal B. Includes structure.
The porous metal complex layer 23-2 composed of the porous metal complex A provided with the organic ligand D including any one of the structures represented by the general formulas (7) to (12) is several nm to several tens nm. Since the cross-linked structure has a gap of a certain degree, it becomes possible to rapidly perform reversible adsorption / desorption of water molecules.

  Therefore, when the moisture concentration is detected by switching from a gas having a low moisture concentration (for example, 10 ppb or less) to a gas having a high moisture concentration (for example, 100 ppm or more), or from a gas having a high moisture concentration to a gas having a low moisture concentration. Even when the moisture concentration is detected, it is difficult to be affected by the moisture contained in the gas that is not the object of measurement, so the reliability of the detection sensitivity of the moisture concentration contained in the gas can be improved.

Next, with reference to FIG. 1, the water concentration detection method of this Embodiment using the water concentration detection unit 10 shown in FIG. 1 is demonstrated.
First, the light source 11 is used to irradiate the surface 23-2a of the porous metal complex layer 23-2 with light having a specific wavelength via the first optical fiber 16.
At this time, light with a specific wavelength within a range of 350 nm to 650 nm, preferably 450 nm to 550 nm may be irradiated.

Next, in a state where the light irradiation by the light source 11 is continued, a gas containing moisture is supplied to the one surface 23-2a of the porous metal complex layer 23-2. At this time, the gas containing moisture is supplied to the one surface 23-2a of the porous metal complex layer 23-2 through the gas supply path 43 and the annular space 51.
As a result, the color of the porous metal complex layer 23-2 changes according to the concentration of moisture contained in the gas, and the intensity of transmitted light that passes through the moisture detection unit 23 changes due to the change in color. The transmitted light is supplied to the light receiving unit 33 via the second optical fiber 28.

Thereafter, the light receiving unit 33 receives the transmitted light that has passed through the moisture detection unit 23 among the light of the specific wavelength, and outputs a voltage corresponding to the intensity of the transmitted light.
Next, the output voltage value of the light receiving unit 33 corresponding to the intensity of the transmitted light is measured using the voltage measuring unit 35. The output voltage value measured by the voltage measurement unit 35 is transmitted to the moisture concentration calculation unit 36.
Next, in the moisture concentration calculation unit 36, a calibration curve indicating the relationship between the moisture concentration contained in the gas stored in the storage unit (not shown) of the moisture concentration calculation unit 36 and the output voltage value of the light receiving unit 33, and the voltage Based on the output voltage value measured by the measuring unit 35, the moisture concentration contained in the gas is calculated.

  In the moisture concentration detection method of the present embodiment, the light source 11 is used to irradiate the surface 23-2a of the porous metal complex layer 23-2 with light of a specific wavelength, and the light irradiation is continued. In the state, the step of supplying a gas containing moisture to the one surface 23-2a of the porous metal complex layer 23-2 and the light transmitted through the moisture detection unit 23 among the light of a specific wavelength by the light receiving unit 33 And a step of generating (outputting) a voltage corresponding to the intensity of the transmitted light, and a step of measuring the voltage by the voltage measuring unit 35. The porous metal complex A is provided with an organic ligand D including any one of the structures represented by the general formulas (7) to (12).

For this reason, the porous metal complex layer 23-2 can quickly perform reversible adsorption / desorption of water molecules.
Therefore, when the moisture concentration is detected by switching from a gas having a low moisture concentration (for example, 10 ppb or less) to a gas having a high moisture concentration (for example, 100 ppm or more), or from a gas having a high moisture concentration to a gas having a low moisture concentration. Even when the moisture concentration is detected, it is less susceptible to the influence of moisture contained in the gas that is not the object of measurement (in other words, the influence of the gas measured immediately before), so the detection sensitivity of the moisture concentration contained in the gas Reliability can be improved.

  The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to such specific embodiments, and within the scope of the present invention described in the claims, Various modifications and changes are possible.

  Hereinafter, although an example and a comparative example are explained, the present invention is not limited to the following example.

(Example)
<Production of moisture detector>
With reference to FIG. 1, the production method of the moisture detection part 23 is demonstrated.
First, a filter 23-1 was produced by cutting out a Teflon (registered trademark) filter (PFO20 (model number) manufactured by Advantech Co., Ltd.) having a thickness of 1 mm so as to be a circle having a diameter of 10 mm.
Next, a dispersion of copper benzene-1,3,5-tricarboxylate (hereinafter referred to as “Cu-BTC”) (a material of the porous metal complex layer 23-2) was produced. The dispersion was designated as Cu-BTC as BASF Ltd. It was prepared by dissolving 1 mg of HKUST-1 (model number) manufactured by KK in 5 mL of acetone.

Next, the entire amount of the produced dispersion was sucked using a microsyringe. Subsequently, SX0001300 (model number) of Nihon Millipore Corporation was prepared as a filter folder, and the filter 23-1 was placed inside the filter folder.
Next, the tip of a microsyringe was attached to the filter folder, and the dispersion liquid sucked into the microsyringe was sprayed on one surface 23-1a of the filter 23-1.
Thereafter, the filter 23-1 coated with the dispersion was naturally dried to form a porous metal complex layer 23-2 having a thickness of 100 μm on one surface 23-1a of the filter 23-1. By such a method, the moisture detection part 23 which has the filter 23-1 and the porous metal complex layer 23-2 was produced.

<Configuration of moisture concentration detection unit>
Here, the configuration of the moisture concentration detection unit 10 shown in FIG. 1 used in the embodiment will be described.
As the light source 11, Kingbright Electronic Co. Ltd .. L-7113QBC-D (model number), which is an LED lamp manufactured by, was used. As the first and second optical fibers 16 and 28, 02-550 (model number) manufactured by Edmund Optics Japan Ltd. was used. As the gas supply pipe 21, 1433 (model number) manufactured by Hikari Mall Co., Ltd. having an inner diameter of 2.0 mm was used.
As the sealing member 24, P-5 (model number) which is an O-ring made by Masoka Co., Ltd. was used. As the light receiving unit 33, TSL-257 (model number) manufactured by TAOS Inc. was used. As the voltage measuring unit 35, DT4281 (model number) manufactured by Hioki Electric Co., Ltd. was used. A commercially available personal computer was used as the moisture concentration calculator 36. Further, as the moisture detection unit 23, the one manufactured by the above-described method was used.

<Preparation of calibration curve>
First, an ultra-high purity nitrogen gas manufactured by Taiyo Nippon Sanso Co., Ltd. with a purity of 99.9999% and a base gas made of Taiyo Nippon Sanso Corporation with a water concentration of 100 ppm. Standard gas was prepared.
Next, by diluting the ultra high purity nitrogen gas and the standard gas, the sample gas E1 having a moisture concentration of 0 ppm, the sample gas E2 having a moisture concentration of 2 ppm, the sample gas E3 having a moisture concentration of 4 ppm, Sample gas E4 having a moisture concentration of 6 ppm, sample gas E5 having a moisture concentration of 8 ppm, sample gas E6 having a moisture concentration of 10 ppm, sample gas E7 having a moisture concentration of 20 ppm, and moisture concentration of 40 ppm Sample gas E8, sample gas E9 having a water concentration of 60 ppm, sample gas E10 having a water concentration of 80 ppm, and sample gas E11 having a water concentration of 100 ppm were prepared.

Subsequently, the power supply 14 was started and the light source 11 was irradiated with light having a wavelength of 470 nm. Next, 1000 sccm of the sample gas E1 having a pressure of 0.1 MPa was supplied to the one surface 23-2a of the porous metal complex layer 23-2. At this time, since the sample gas E1 did not contain moisture, no change was observed in the color of the porous metal complex layer 23-2.
Thereafter, using the voltage measuring unit 35, the output voltage value of the light receiving unit 33 corresponding to the intensity of the transmitted light transmitted through the moisture detecting unit 23 supplied with the sample gas E1 was measured. The output voltage value in this case was 0.1V.

Subsequently, the light source 11 was irradiated with light having a wavelength of 500 nm, and then, 1000 sccm of the sample gas E2 having a pressure of 0.1 MPa was supplied to the one surface 23-2a of the porous metal complex layer 23-2. At this time, since the sample gas E2 contains moisture at a concentration of 2 ppm, the porous metal complex layer 23-2 changed to a blue color.
Thereafter, using the voltage measuring unit 35, the output voltage value of the light receiving unit 33 corresponding to the intensity of the transmitted light transmitted through the moisture detecting unit 23 supplied with the sample gas E2 was measured. The voltage value in this case was 0.12V, and the voltage difference from the time when the sample gas E1 was introduced was 0.02V.

Next, the same processing as the processing for obtaining the output voltage value of the light receiving unit 33 when the sample gas E2 is supplied was performed on the sample gases E3 to D11.
As a result, the output voltage value of the light receiving unit 33 when the sample gas E3 is supplied is 0.14V (voltage difference 0.04V), and the output voltage value of the light receiving unit 33 when the sample gas E4 is supplied is 0.16V ( When the sample gas E5 is supplied, the output voltage value of the light receiving unit 33 is 0.18V (voltage difference 0.08V), and when the sample gas E6 is supplied, the output voltage value of the light receiving unit 33 is The output voltage value of the light receiving part 33 when the sample gas E7 is supplied is 0.2V (voltage difference 0.14V), and the light receiving part 33 when the sample gas E8 is supplied. The output voltage value is 0.3V (voltage difference 0.2V), the output voltage value of the light receiving unit 33 when the sample gas E9 is supplied is 0.14V (voltage difference 0.04V), and the sample gas E10 is supplied. The output voltage value of the light receiving unit 33 is 0.4 V (voltage difference 0.3 ), The output voltage value of the light receiving portion 33 when the supply of the sample gas E11 was 0.43 V (voltage difference 0.33 V).

FIG. 2 shows the result of plotting the moisture concentration contained in the sample gases E1 to D11 and the voltage value of the light receiving unit 33 when the sample gases E1 to D11 are supplied.
FIG. 2 is a graph of a calibration curve showing the relationship between the moisture concentration contained in the sample gas and the voltage output value of the light receiving unit.

<Detection sensitivity of moisture concentration>
Using the calibration curve shown in FIG. 2, the moisture concentration detection sensitivity (detection limit) when the moisture concentration detection unit 10 of the example was used was calculated by the signal noise ratio (S / N ratio) calculation method. Specifically, the detection limit (hereinafter referred to as “detection limit L”) was determined using the following formula (I).
In the following formula (I), L is the detection limit, S is the signal intensity of the sample gas, N is the noise width, and C is the moisture concentration in the sample gas. In the following formula (I), a value twice the noise width is defined as the detection limit L.

  L = (N / S) × 2C (I)

  By substituting N = 1 mV, S = 20 mV, and C = 100 ppb into the above formula (I), the water concentration that can be detected by the water concentration detection unit 10 of the embodiment is 10 ppb (= detection limit L). I understood.

<Evaluation of response speed>
Next, an ultra-high purity nitrogen gas manufactured by Taiyo Nippon Sanso Co., Ltd. with a purity of 99.9999%, and a base gas manufactured by Taiyo Nippon Sanso Corporation with a moisture concentration of 100 ppm. The standard gas was alternately supplied to the one surface 23-2a of the porous metal complex layer 23-2, and the output voltage value output from the light receiving unit 33 at this time was measured. The result is shown in FIG.

FIG. 3 is a graph showing the relationship between the elapsed time from the start of gas supply and the voltage output value of the light receiving unit.
Referring to FIG. 3, when switching from the state in which ultra-high purity nitrogen gas is supplied to the standard gas, the time for the output voltage value of the light receiving unit 33 to switch to the output voltage value resulting from the standard gas is about 1 minute. It was about.
In addition, when the standard gas is supplied and switched to the ultra high purity nitrogen gas, the time for the output voltage value of the light receiving unit 33 to switch to the output voltage value caused by the ultra high purity nitrogen gas is about 3 minutes. there were.

<Examination of wavelength of light emitted from light source>
Here, the light source 11 is replaced with the above-described LED lamp, except that DL SHGpro (model number), which is a semiconductor laser irradiation device manufactured by Indeco Co., Ltd., capable of changing the wavelength of light to be irradiated, is used. An apparatus having the same configuration as the moisture concentration detection unit 10 described above was used.
And the wavelength range of light (light irradiated from a semiconductor laser irradiation apparatus) required in order to detect the intensity | strength of transmitted light as a voltage value was examined.

At this time, a standard gas manufactured by Taiyo Nippon Sanso Co., Ltd. having a moisture concentration of 1 ppm was supplied to one surface 23-2a of the porous metal complex layer 23-2.
The wavelengths of light emitted from the semiconductor laser irradiation apparatus were 350 nm, 375 nm, 400 nm, 425 nm, 450 nm, 475 nm, 500 nm, 525 nm, 550 nm, 575 nm, 600 nm, 625 nm, 650 nm, 675 nm, and 700 nm. And the output voltage value output from the light-receiving part 33 at each wavelength was measured. The result is shown in FIG.

FIG. 4 is a graph showing the relationship between the wavelength of light applied to the porous metal complex layer and the voltage output value of the light receiving unit.
Although it is difficult to understand from FIG. 4, the voltage output value of the light receiving unit 33 when the wavelength is 350 nm is 0.1 V, and the voltage output value of the light receiving unit 33 when the wavelength is 650 nm is 0.1 V. Further, the voltage output value of the light receiving unit 33 when the wavelength was 675 nm and 700 nm was 0.1V.
From the results shown in FIG. 4, it was confirmed that the wavelength range of light necessary for detecting the intensity of transmitted light as a voltage value is 350 nm or more and 650 nm or less.
Moreover, it has confirmed that the wavelength range of the light required in order to make the voltage output value of the light-receiving part 33 0.004V or more is 450 nm or more and 550 nm or less.

(Comparative Example 1)
In Comparative Example 1, in place of the copper benzene-1,3,5-tricarboxylate used in the examples, a Phthalocyanine Copper (II) which is a copper phthalylocyanine manufactured by Wako Pure Chemical Industries, Ltd. was used. A moisture detection part of Comparative Example 1 was produced in the same manner except that the metal complex layer was produced.
The porous metal complex layer of Comparative Example 1 was produced by the same method as the porous metal complex layer 23-2 of the example. Moreover, the thickness of the porous metal complex layer of Comparative Example 1 was 100 μm. As the substrate of Comparative Example 1, the Teflon (registered trademark) filter (PFO20 (model number) manufactured by ADVANTEC) having a thickness of 1 mm and a diameter of 10 mm described in the examples was used.

Next, the moisture detection unit of Comparative Example 1 is set in the moisture concentration detection unit 10 shown in FIG. 1, and a standard gas manufactured by Taiyo Nippon Sanso Corporation with a base gas of nitrogen gas and a moisture concentration of 300 ppb is used. When the output voltage value of the light-receiving part 33 according to the intensity | strength of the transmitted light at this time was measured by supplying to the porous metal complex layer of the comparative example 1, the output of the voltage from the light-receiving part 33 was not able to be confirmed.
A similar test was conducted using a standard gas made by Taiyo Nippon Sanso Corporation with a base gas of nitrogen gas and a water concentration of 500 ppb, and a standard gas made by Taiyo Nippon Sanso Corporation with a water concentration of 1000 ppb. And performed using. Even in the case of these standard gases, voltage output from the light receiving unit 33 could not be confirmed.
Further, when the above three kinds of standard gases were used, no change in the color of the porous metal complex layer of Comparative Example 1 was observed. From this, it was confirmed that the color of the porous metal complex layer of Comparative Example 1 did not change due to the reaction with moisture.

(Comparative Example 2)
First, MS-1 which is a moisture detection sensor manufactured by GE Sensing & Inspection Technologies Co., Ltd. adopting the same principle as the capacitance sensor described in Patent Document 1, and a purity of 99.9999%. An ultra-high purity nitrogen gas manufactured by Nippon Oil & Acid Co., Ltd. and a standard gas manufactured by Taiyo Nippon Sanso Co., Ltd. having a base gas of nitrogen gas and a water concentration of 100 ppm were prepared.

  Next, the ultrahigh purity nitrogen gas and the standard gas were diluted with the diluter used in the examples to change the moisture concentration, and the moisture concentration detection limit of the moisture detection sensor (MS-1) was calculated. As a result, the detection limit of the moisture concentration of the moisture detection sensor (MS-1) was 0.5 ppm (500 ppb).

Next, the ultra-high purity nitrogen gas is first supplied to the moisture detection sensor (MS-1), and then the supply of the ultra-high purity nitrogen gas is stopped and then the standard gas is supplied, and then the standard gas is supplied. After stopping supply of ultra high purity nitrogen gas, the signal output time from the moisture detection sensor (MS-1) was continuously measured.
As a result, when the ultra high purity nitrogen gas was switched to the standard gas, the time until the output signal of the moisture detection sensor (MS-1) became an output signal related to the standard gas was about 30 minutes. When the standard gas was switched to the ultra high purity nitrogen gas, the time until the output signal of the moisture detection sensor (MS-1) became an output signal related to the ultra high purity nitrogen gas was about 44 minutes.

(Summary of evaluation results of detection sensitivity of moisture concentration in Example and Comparative Example 2)
From the result of the detection sensitivity of the moisture concentration in the above-mentioned example and comparative example 2, the detection limit of comparative example 2 is 0.5 ppm (500 ppb), whereas in the example, the detection limit is 10 ppb. It was confirmed that the moisture detection sensitivity of the moisture detector 23 was very high.

(Summary of evaluation results of response speed of Example and Comparative Example 2)
From the result of the response speed of the above example and comparative example 2, when switching from the ultra high purity nitrogen gas to the standard gas, the time until the voltage value or the output signal related to the standard gas becomes the comparative example in the case of the example. It was confirmed that about 1/30 of the time was sufficient.
In addition, when switching from the standard gas to the ultra-high purity nitrogen gas, it was confirmed that in the example, it took about 1/15 of the time of Comparative Example 2.
From the above results, it was confirmed that the moisture detection unit 23 of the example had a very fast response speed when the gas was switched compared to the moisture detection sensor (MS-1) of the comparative example 2.

  The present invention is applicable to a moisture concentration detection unit that detects a moisture concentration contained in a gas.

  DESCRIPTION OF SYMBOLS 10 ... Moisture concentration detection unit, 11 ... Light source, 11A ... Positive terminal, 11B ... Negative terminal, 13 ... Light source position control member, 13A ... Penetration part, 14 ... Power supply, 16 ... First optical fiber, 16A, 28A ... One end , 16B, 28B ... the other end, 16-1, 28-1 ... core part, 16-2, 28-2 ... clad part, 18 ... gas path built-in member, 21 ... gas supply pipe, 21A ... notch part, 23 ... moisture detector, 23-1 ... filter, 23-1a, 23-2a ... one side, 23-1b ... other side, 23-2 ... porous metal complex layer, 24 ... seal member, 26 ... moisture detector fixing member , 26a ... lower surface, 26A, 31A, 42 ... insertion hole, 28 ... second optical fiber, 31 ... light receiving portion fixing member, 31a ... upper surface, 33 ... light receiving portion, 35 ... voltage measuring portion, 36 ... moisture concentration calculating portion 38 ... first part, 39 ... second Portion, 41 ... member body, 43 ... gas supply path 45 ... porous metal complex layer exposed portion, 46 ... gas discharge passage, 51 ... annular space

Claims (5)

A moisture concentration detection unit for detecting the concentration of moisture contained in gas,
A moisture detector comprising a filter having light permeability and a porous metal complex layer made of a porous metal complex covering one surface of the filter;
A light source that emits light of a specific wavelength to one surface of the porous metal complex layer located on the opposite side of the surface that contacts one surface of the filter;
A gas supply path for supplying the gas to one surface of the porous metal complex layer;
It is arranged to face the light source through the moisture detection unit, receives transmitted light that is emitted from the light source and transmitted through the moisture detection unit, and generates a voltage according to the intensity of the transmitted light. A light receiver;
A voltage measuring unit for measuring the voltage;
Have
The porous metal complex includes a metal and an organic ligand coordinated with the metal,
The said organic ligand contains the structure in any one shown by following General formula (1)-(6), The moisture concentration detection unit characterized by the above-mentioned.

  The moisture concentration detecting unit according to claim 1, wherein the metal is Cu or Co.   The moisture concentration detection unit according to claim 1 or 2, wherein the porous metal complex is copper benzene-1,3,5-tricarboxylate.   4. The moisture concentration detection unit according to claim 1, wherein the light emitted from the light source has a wavelength of 350 nm or more and 650 nm or less. 5. A moisture concentration detection method using the moisture concentration detection unit according to any one of claims 1 to 4,
Irradiating one surface of the porous metal complex layer with light of the specific wavelength using the light source;
Supplying the gas containing the moisture to one surface of the porous metal complex layer in a state where the light irradiation is continued;
A step of receiving the transmitted light transmitted through the moisture detection unit out of the light of the specific wavelength by the light receiving unit, and generating a voltage according to the intensity of the transmitted light;
Measuring the voltage by the voltage measuring unit;
A method for detecting moisture concentration, comprising:

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