JP3102813B2 - Temperature sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature sensor,
More specifically, the present invention relates to a temperature sensor containing a polypyridine metal complex or a derivative thereof.

[0002]

2. Description of the Related Art Conventionally, there have been many temperature sensors widely used, such as a thermocouple, a thermistor, a mercury column, and a radiation thermometer. Since thermocouples and thermistors measure temperature by measuring thermoelectromotive force or electrical resistance, electromagnetic induction noise from the outside is likely to be generated, and there is a risk of leakage under high voltage. Further, the measurement object of the mercury column thermometer is limited due to its large heat capacity and outer diameter. Further, the radiation thermometer has a drawback that it cannot measure the temperature inside the object because it measures heat radiation such as infrared rays from the measurement object.

As a method for solving the above-mentioned drawbacks in the conventional temperature measuring method, a temperature measuring method using an optical fiber has been devised. These are a method of optically detecting the degree of deformation of the optical fiber itself or a metal foil due to heat, a method of measuring Raman scattered light, and a method of fixing a luminescent compound at the tip of the optical fiber and measuring the luminescence. Can be roughly divided into two.

The third method has a wide range of choices of luminescent compounds that can be used, and the method of measuring the temperature is simpler than the other two methods. As an example of the third method, Japanese Patent Laying-Open No. 54-62879 proposes a method of measuring the temperature by detecting the intensity of light emission of CdS or GaAs. In addition, as a luminescent compound, a cobalt complex salt, (YF ₃
A temperature measurement method by a spectral absorption method using a fluorescent substance such as Yb, Er), Gd ₂ O ₂ S, Lu (CrAl _1-x ) ₃ (BO ₃ ) ₄ has been devised (M. Brenci, G. Conforti, R. Falciai, AG Mig
nani and M. Scheggi; Conf, Proc. OFS '84, P15
Five).

[0005]

However, since these luminescent compounds do not have linear luminescence intensity characteristics with respect to temperature change, when the luminescent compound is used for a temperature sensor, the fluorescence lifetime is measured. Temperature (in the case of YF ₃ .Yb, Er), the temperature must be calculated from the intensity ratio of the two wavelengths of the emission spectrum, which has the disadvantage that the temperature measurement device is complicated and expensive.

Accordingly, it is an object of the present invention to provide a temperature sensor that overcomes the above-mentioned disadvantages of the prior art. That is, an object of the present invention is to provide a temperature sensor that can easily measure a temperature by measuring only the emission intensity without measuring the emission intensity ratio or the fluorescence lifetime of two wavelengths.

[0007]

Means for Solving the Problems As a result of diligent efforts of the present inventors, they have found that the above-mentioned problems can be solved by using a polypyridine metal complex or a derivative thereof for a temperature sensor, and have accomplished the present invention. Reached. That is, the present invention provides a temperature sensor containing a polypyridine metal complex or a derivative thereof.

[0008] The polypyridine metal complex or its derivative used in the present invention refers to a complex comprising polypyridine or its derivative and a transition metal ion. Examples of the polypyridine include bipyridine, terpyridine, phenanthroline, and the like. As derivatives of polypyridine, 4,
4'-dicarboxy-2,2'-bipyridine and the like.

Examples of the transition metal ions include ions of ruthenium, rhodium, osmium, iridium, iron and the like belonging to Group 8, and ions of lanthanoids such as europium and terbium. Polypyridine Examples of the metal complex or a derivative thereof, tris (2,2'-bipyridine) ruthenium (II) complex ^{_{(Ru (bpy) 3 2+ ·}} 2X -, where X ^- is Cl
^{-, Br -, I -,} ClO 4 - is an anion such as a), tris (4,4'-dicarboxy-2,2'-bipyridine) ruthenium (II) complex (Ru (dcbpy) (bpy) ₂ ²⁺ · 2X ^-, but
X ^- is ^{Cl -, Br -, I -} , ClO 4 - , and the like of the anion)
, Tris (O-phenanthroline) ruthenium (II)
Complexes, bis (terpyridine) iridium (II) complexes and the like, among which tris (2,2'-bipyridine)
Ruthenium (II) complexes, tris (4,4'-dicarboxy-2,2'-bipyridine) ruthenium (II) complexes and the like are preferred. The polypyridine metal complex or a derivative thereof may be used alone or in combination of two or more.

The Stokes shift of a polypyridine metal complex or a derivative thereof is near 150 nm, and it is easy to separate excitation light and light emission. The reason that the light emission from the polypyridine metal complex or its derivative varies depending on the temperature is due to the process in which the excited state and the charge separation state of the polypyridine metal complex are deactivated and the speed varies depending on the temperature. That is,
The polypyridine metal complex emits extra energy as light emission (fluorescence or phosphorescence) when an electron returns from its excited state to its original ground state. In addition to this, deactivation due to internal rotation of molecules and heat around There are processes such as release of energy and deactivation, and processes of causing an electron transfer reaction with other compounds, which significantly affect the intensity of light emission. When the temperature rises, energy is lost due to collision of complex molecules,
As a result of an increase in non-radiative deactivation processes such as internal rotation, the emission intensity is significantly reduced.

The polypyridine metal complex or its derivative may be used as a powder or as a film. When forming a polypyridine metal complex or a derivative thereof into a film, a binder may be used. Further, a film containing a polypyridine metal complex or a derivative thereof can be provided on a support. When the powder of the polypyridine metal complex or a derivative thereof is used as it is, the powder is filled in a capillary such as glass, plastic, or the like, or is fixed on a substrate such as glass, plastic, rubber, or the like or at the tip of a wire. , Temperature sensor.

When a polypyridine metal complex or a derivative thereof is formed into a film, the polypyridine metal complex or a derivative thereof is formed by vapor deposition, ion plating, sputtering,
The film can be formed by a thermal CVD method, a plasma CVD method, an optical CVD method, an electrolytic polymerization method, or the like. The thickness of the polypyridine metal complex or a derivative thereof is 0.01 to 1000 μm.
m is preferred. If the thickness of the polypyridine metal complex or its derivative is more than 1000 μm, there is a problem that the sensitivity is reduced.

Further, a polypyridine metal complex or a derivative thereof may be formed into a film using a binder. As the binder, solid acids, glass, synthetic and natural polymer compounds and the like can be used. "Solid acids" include kaolin, bentonite, clay such as montmorillonite, silica gel, alumina, silica alumina, alumina boria, molybdic acid and its salts, tungstic acid and its salts,
Examples thereof include inorganic compounds such as vanadate, and those obtained by supporting sulfuric acid or phosphoric acid on the above solid acid.

As the high molecular compound, perfluorocarbon sulfonic acid, polystyrene sulfonic acid, polyacrylic acid, polymethyl methacrylate, silk fibroin,
Examples include cellulose and gelatin. The binder is
They may be used alone or in combination of two or more. The content of the polypyridine metal complex or a derivative thereof is in a molar concentration of 0.01 mM to 1 M based on the volume of the binder.
It is preferred that it is about. When the content of the polypyridine metal complex or its derivative is less than 0.01 mM, there is a problem that light emission is weak. When the content of the polypyridine metal complex or its derivative is more than 1M, there is a problem that concentration quenching occurs.

Further, the above-mentioned film containing a polypyridine metal complex or a derivative thereof is provided on a substrate such as a ceramic substrate, a glass substrate, a plastic substrate, a rubber substrate, a metal substrate, a natural polymer substrate, or a support such as an optical fiber. You may. The substrate preferably has a thickness of 0.01 to 10 mm. A film containing a polypyridine metal complex or a derivative thereof and a binder can be prepared by immersing a solution of the polypyridine metal complex or a derivative thereof in the formed binder film. Alternatively, a solution or dispersion containing a polypyridine metal complex or a derivative thereof and a binder is prepared,
It can be prepared by applying this solution or dispersion on a support.

In the first method, Nafion 117
Commercially available binder membranes such as a membrane (perfluorocarbon sulfonic acid manufactured by Du Pont), a silica gel sheet, an alumina sheet, a cellulose paper, and a silk nonwoven fabric can be used. Further, a binder film produced by a method such as a stretching method, a solution coating method, and a spin coating method may be used.

For example, when a binder film is formed by a solution coating method, a binder solution or dispersion is first prepared. As the solvent or the dispersion medium, water, alcohol, other organic solvents, and the like can be used. The content of the binder in the solution or dispersion is 0.1 to 30% by weight, preferably 1 to 20% by weight, based on the total weight of the solution or dispersion.

The solution or dispersion of the above-mentioned binder can be applied to a support by a method such as a dropping method, a dipping method, and a spin coating method. When a film is formed on a substrate made of ceramic, glass, plastic, rubber, metal, or the like, any of the above methods can be used. However, when a film is formed on an optical fiber or the like, a dipping method is preferable. The binder film formed as described above is dried using a vacuum dryer, an oven, a dryer, or the like under the conditions of 10 ^{−3 to} 760 mmHg and 20 to 220 ° C. Further, after drying, the binder film may be subjected to treatment such as immersion in alcohol or the like, heat treatment, or the like.

The thickness of the binder film is 0.01 to 1000 μm
(Dry film thickness) is preferable, and 0.1 to 200 μm is particularly preferable. When the thickness of the binder film is smaller than 0.01 μm, there is a problem that light emission is weak. When the thickness of the binder film is 1
If it is larger than mm, there is a problem that the sensitivity is reduced.
The binder film is immersed in a solution of the polypyridine metal complex or its derivative. The solution of the polypyridine metal complex or its derivative is prepared by dissolving the above-mentioned polypyridine metal complex or its derivative in water, alcohol, another organic solvent, or the like. A suitable solvent is selected according to the combination of the complex and the binder. The concentration of the polypyridine metal complex or a derivative thereof in the solution is 10 μM to 0.1 M, preferably 1 to 50 mM, based on the total volume of the solution.

The binder film is added to a solution of the above-mentioned polypyridine metal complex or a derivative thereof at a temperature of 10 to 50 ° C. for 0.1 minute.
Soak for 0.5 to 24 hours. Thereafter, the binder film containing the polypyridine metal complex or a derivative thereof becomes 10 ^{-3 to} 76.
It is dried under the conditions of 0 mmHg, 20 to 220 ° C. and 30 to 180 minutes. In the second method, first, a solution or dispersion containing a polypyridine metal complex or a derivative thereof and a binder is prepared. As the solvent or the dispersion medium, water, alcohol, and other organic solvents can be used. The ratio of the polypyridine metal complex or its derivative to the binder is preferably the same value as in the first method, and the polypyridine metal complex or The concentration of the solids containing the derivative and the binder is 0.1 to 30% by weight based on the total weight of the solution or dispersion.
Is preferred, and particularly preferably 1 to 20% by weight.

The above solution or dispersion is prepared by a dropping method, a dipping method,
It can be applied onto a support by a method such as spin coating. Examples of the support include those described above. When forming a film on a substrate such as ceramic, glass, plastic, rubber, and metal, any of the above methods can be used,
When forming a film on an optical fiber or the like, the dipping method is preferable.

The film produced as described above has a thickness of 10 ^-3.
It is dried using a vacuum dryer, an oven, a dryer, etc. under the conditions of ７760 mmHg, 20-220 ° C. and 30-180 minutes. The thickness of the film containing the polypyridine metal complex or its derivative and the binder is preferably 0.01 to 1000 μm (dry film thickness). If the film thickness is less than 0.01 μm, there is a problem that light emission is weak. On the other hand, when the film thickness is larger than 1000 μm, there is a problem that the response time to the temperature change becomes long.

As used herein, the term "membrane containing a polypyridine metal complex or a derivative thereof and a binder" means that the polypyridine metal complex or a derivative thereof is chemically bonded to the binder, physically and / or chemically adsorbed, or It simply means a membrane in which a polypyridine metal complex or a derivative thereof and a binder are mixed. The film containing the polypyridine metal complex or the derivative thereof and the binder produced by the above first or second method,
Further, heat treatment, solvent treatment, and the like may be performed. Through the above processing, the film structure can be changed.

The heat treatment is performed in the range of 10 ⁻³ mmHg to normal pressure for 5 hours.
It is performed by maintaining the temperature at 0 to 250 ° C. For example, a perfluorocarbon sulfonic acid (trade name: Nafion) film forms clusters (micelles) of hydrophobic groups at 120 ° C. or lower, but the structure is inverted by vacuum drying at 120 ° C. or higher, resulting in an anionic property. Form a dipole cluster consisting of hydrophilic and water molecules. The films having different film structures have different characteristics.

For the solvent treatment, for example, the film is immersed in an 80% alcohol / water solution for 10 minutes, and then at 60 ° C. for 1 hour.
It can be carried out by vacuum drying under the condition of ^{-3 to} 760 mmHg. The film containing the above polypyridine metal complex or its derivative and a binder can be used as a temperature sensor in any temperature measurement system regardless of gas phase, liquid phase, vacuum system, or solid phase.

Hereinafter, the present invention will be described in more detail using preferred embodiments. The scope of the present invention is not limited to the following examples.

[0027]

【Example】

[0028]

Reference Example 1 Tris (2,2 ′) represented by the following formula (I)
- bipyridine) ruthenium (II) complex (hereinafter referred to as Ru (bpy) ₃ ²⁺
· 2Cl ^- in 10mM in an aqueous solution of referred to) and, 1cm × 3cm × 0.
After immersing 17 mm Nafion 117 membrane (Du Pont perfluorocarbon sulfonic acid membrane) for 1 hour,
Washed with deionized water to obtain a film containing Ru (bpy) ₃ ²⁺ and perfluorocarbon sulfonic acid was heated and dried for 120 minutes at 60 ° C.. The dry film thickness of this film was 170 μm.

[0029]

Embedded image

This was placed on a four-sided transparent fluorescent cell (1 cm × 1c).
m) and fixed at the diagonal position of the fluorescence spectrophotometer (trade name R
F-5000, manufactured by Shimadzu Corporation) and irradiated with excitation light of 456 nm. At various temperatures, the emission intensity at the maximum emission wavelength (603 nm) from the excited state was measured.
As shown in FIG. 1, a curve was obtained in which the emission intensity decreased with increasing temperature. Using this as a calibration curve, the ambient temperature could be determined by measuring the emission intensity.

The time was about 7 seconds as shown in FIG.

[0032]

REFERENCE EXAMPLE 2 A (4,4'-dicarboxy-2,2'-bipyridine) bis (2,2'-bipyridine) ruthenium (II) complex (hereinafter Ru (DCbpy)) represented by the following formula (II) (bpy) ₂ ²⁺
2Cl ⁻ ) in a 10 mM aqueous solution of 1 cm × 3 cm × 17
0μm Nafion 117 membrane (Du Pont Company of perfluorocarbon sulfonic acid membrane) was soaked for 1 hour, after rinsing with deionized water, and dried by heating for 120 minutes at 60 ℃, Ru (DCbpy) ( bpy) 2 2 A membrane containing ⁺ and perfluorocarbonsulfonic acid was obtained. The dry thickness of this film is 170μ
m.

[0033]

Embedded image

This film was 456 nm thick in the same manner as in Example 1.
Irradiates with the excitation light, and the maximum emission wavelength (58
When the emission intensity at 5 nm was measured, a curve was obtained in which the emission intensity decreased with increasing temperature, as shown in FIG. Using this as a calibration curve, the ambient temperature could be determined by measuring the emission intensity.

[0035]

REFERENCE EXAMPLE 3 Tris (4,4) represented by the following formula (III)
4'-dicarboxy-2,2'-bipyridine) ruthenium (II) complex (hereinafter ^{_{Ru (DCbpy) 3 2+ · 2Cl}} - and referred) 10 mM of
1 cm × 3 cm × 170 μm Nafion 11 in aqueous solution
7 membrane (Du Pont's perfluorocarbon sulfonic acid membrane) was immersed for 1 hour, washed with ion-exchanged water,
60 and dried by heating for 120 minutes at ° C., to obtain a film containing Ru (DCbpy) ₃ ²⁺ and perfluorocarbon sulfonic acid. The dry film thickness of this film was 170 μm.

[0036]

Embedded image

The thickness of this film was 456 nm in the same manner as in Example 1.
Irradiates with the excitation light, and the maximum emission wavelength (58
When the emission intensity at 5 nm) was measured, a curve was obtained in which the emission intensity decreased with increasing temperature as shown in FIG. Using this as a calibration curve, the ambient temperature could be determined by measuring the emission intensity.

[0038]

[Reference Example 4] ^{_{Ru (bpy) 3 2+ · 2Cl}} - of 0.1mM aqueous solution 50m
During l, after dispersing the silica gel 5g, washed with water and the residue was filtered dispersion to obtain a precipitate containing Ru (bpy) ₃ ²⁺ and silica gel complex. 500 mg of this precipitate is 1 mm in diameter
To the tip of a quartz fiber (manufactured by Toray Industries, Inc.)
Vacuum dried at 20 ° C. for 120 minutes. The dry film thickness of this film was 150 μm.

Monochromatic light of 456 nm was extracted from the light of a 150 W xenon lamp through an interference filter, led to an optical fiber through a dichroic mirror, and irradiated on a film containing a composite of Ru (DCbpy) ₃ ²⁺ and silica gel at the tip. Light emitted from the optical fiber was reflected by the dichroic mirror and taken out, and the intensity of only 585 nm light was measured through an interference filter. When the relationship between the relative emission intensity and the temperature was determined,
As shown in FIG. 4, a curve was obtained in which the emission intensity decreased with increasing temperature. Using this as a calibration curve, the temperature at the tip of the optical fiber could be determined by measuring the emission intensity.

[0040]

Example 5 5% by weight of perfluorocarbon sulfo
Acid solution (made by Du Pont, trade name: Nafion)
Film is formed on the tip of a 1 mm diameter quartz fiber
Heat drying at 20 ° C. for 1 hour. This quartz fiber tip
To Ru (bpy)_Three ²⁺・ 2Cl^-And HgCl _TwoConsisting of a molar ratio of 1/2
Complex salt (Ru (bpy)_Three ²⁺・ (Hg_TwoCl₆)^2-(Hereinafter referred to as Ru-Hg)
In 10 mM dimethylformamide solution for 10 minutes
After immersion, wash with dimethylformamide and
At 1 ° C for 1 hour.
Immerse in 100 ml of butyl acetate solution of methyl methacrylate
And dried by heating at 140 ° C for 1 hour.
Consists of a membrane containing a complex of fluorocarbonsulfonic acid
A temperature sensor was obtained. The dry thickness of this film is 2 μm
Met. Interference noise from the light of a 150 W xenon lamp
456nm monochromatic light is extracted through a filter
Guide to the quartz fiber through the Loic mirror, the tip
Of Ru-Hg and perfluorocarbon sulfonic acid complex
The film containing was irradiated. Returned from the optical fiber
The emitted light is reflected by the dichroic mirror and collected.
Of light of 600 nm through the interference filter.
Only the light was taken out and the luminescence intensity was measured. This relative emission intensity
When the relationship between the temperature and the temperature was determined, as shown in FIG.
A curve is obtained in which the logarithm of the emission intensity decreases in proportion to the increase.
Was. This is used as a calibration curve to measure the emission intensity.
The ambient temperature could be determined.

[0041]

According to the temperature sensor of the present invention, the temperature in gas, liquid and solid can be measured safely and simply without generating electromagnetic induction noise and without danger of electric leakage even under high voltage. Can be. Further, since the temperature sensor of the present invention shows a linear change in emission intensity with respect to a temperature change, the temperature in a gas, a liquid, and a solid can be measured by a simple measurement system by using the sensor.

[Brief description of the drawings]

FIG. 1 is a graph showing a relationship between a temperature around a film and a relative light emission intensity obtained in Example 1. Here, the relative luminous intensity is the luminous intensity at each temperature when the luminous intensity at 20 ° C. is set to 1.

FIG. 2 is a graph showing a relationship between a temperature around a film and a relative light emission intensity obtained in Example 2.

FIG. 3 is a graph showing a relationship between a temperature around a film and a relative light emission intensity obtained in Example 3.

FIG. 4 is a graph showing the relationship between the temperature around the film and the relative light emission intensity obtained in Example 4.

FIG. 5 is a graph showing the relationship between the temperature around the film and the relative luminescence intensity obtained in Example 5.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masao Kaneko 2-1 Hirosawa, Wako-shi, Saitama Pref. RIKEN (56) References JP-A-63-253225 (JP, A) (58) Fields investigated (Int) .Cl. ⁷ , DB name) G01K 11/20 G01K 11/12

Claims (5)

(57) [Claims] 1. A ^{_{Ru (bpy) 3 2+ · (}} Hg 2 Cl 6) Temperature sensor comprising ^2-. 2. The temperature sensor according to claim 1, further comprising a solid acid. 3. The temperature sensor according to claim 1, further comprising a polymer compound. 4. A temperature sensor comprising a support and ^{_{Ru (bpy) 3 2+ · (}} Hg 2 Cl 6) layer containing ^2-. 5. The temperature sensor according to claim 4, wherein the support is an optical fiber.