JP3051751B2 - Thermal analyzer with generated gas analysis function - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention measures changes in physical characteristics of a sample while changing the temperature of the sample, and also analyzes characteristics of a gas generated from the sample. The present invention relates to a thermal analyzer having a function.

2. Description of the Related Art A thermoanalytical device that measures the physical properties of a sample while changing the temperature of the sample, in this case, a change in weight, such as a thermogravimetric device (TG device) is known. Also,
In addition to the measurement of such physical properties, a thermal analysis apparatus having a function of analyzing a generated gas, which simultaneously analyzes a gas generated from a sample, is already known.

This type of thermal analyzer generally includes a protective tube that shields a sample stage on which a sample is placed from the outside, a heater disposed around the protective tube to heat the sample, It is composed of a gas analyzer for analyzing the generated gas, and a gas transfer pipe for transferring the gas generated from the sample to the gas analyzer by a carrier gas.

Various types of gas analyzers are conceivable.For example, when a quadrupole mass spectrometer is used, the gas generated from the sample is transported by the carrier gas through the gas transfer pipe to the quadrupole mass analyzer. The gas is carried to the polar mass spectrometer, and the type of the gas is identified by measuring the mass number of the gas component in the quadrupole mass spectrometer.

As described above, when a gas analyzer such as a quadrupole mass spectrometer is attached to the protective tube, a carrier gas gas flow is formed in the protective tube, and the generated gas must be carried to the gas analyzer by the carrier gas. Must. In this case, originally, only the gas generated from the sample must be transported, but depending on how the carrier gas flows, background that should not be transported, such as CO ₂ , O ₂ , H _2, etc. Components (components that hinder the analysis of generated gas) are transported to the gas analyzer, and as a result, there has been a problem that accurate gas analysis cannot be performed.

Further, depending on the shape and characteristics of the gas transfer pipe for transferring the gas generated from the sample to the gas analyzer, the generated gas is deteriorated during the transfer, so that accurate gas analysis could not be performed. Considering the fact that the gas transport pipe is manufactured using a metal material, the metal material exerts a catalytic action to a certain extent, so that the gas flowing through it cannot be inevitably deteriorated.

[Problems to be Solved by the Invention] The present invention has been made in view of the above-mentioned various problems in a thermal analysis apparatus having a generated gas analysis function, and has a high accuracy in gas analysis measurement of generated gas. It is a first object of the present invention to provide a thermal analyzer capable of performing the above.

It is a second object of the present invention to provide a thermal analyzer having a generated gas analyzing function with good workability.

Means for Solving the Problems In order to achieve the first object, a first thermal analyzer according to the present invention is a capillary glass tube arranged from a position immediately above a sample in a protective tube to a gas analyzer. And a coating tube coated around the capillary glass tube to form a gas transfer tube.

[Operation] In the thermal analyzer according to claim 1, when gas is generated from the sample (10) during the thermal analysis measurement, the generated gas is transferred into the capillary glass tube (14) by the carrier gas. To the gas analyzer (mass analyzer 2) through the capillary glass tube. Since the glass tube has a low catalytic ability for gas, the gas to be conveyed does not deteriorate.

In addition, since the generated gas is transported using a capillary tube with an extremely small inner diameter, the flow velocity of the transported gas is high, and the gas generated in the sample can be instantly transported to the gas analyzer, and therefore thermogravimetric measurement, etc. Thermal analysis and gas analysis can be performed almost simultaneously, that is, in real time.

[Embodiment] Fig. 1 shows an embodiment of the present invention, in which a mass spectrometer 2 as a device having an evolved gas analysis function is attached to a thermogravimetric device (TG device) 1. That is, the TG device 1 measures the weight change of the sample due to the temperature change, and the mass spectrometer 2 measures the mass number of the gas generated from the sample that causes the weight change, that is, identifies the gas. Is what you do.

In FIG. 1, a TG device 1 includes a protective tube 3 made of quartz glass or the like, a weight measuring unit 4 disposed below the protective tube 3, and a heater 5 disposed around the protective tube 3. have.

A weighing mechanism 6 known per se is provided in the weighing unit 4, and a support rod 7 supported by the weighing mechanism 6 passes through the cover opening 8 of the weighing unit 4 and the inside of the protective tube 3. Extending to A sample stage 9 is fixed to the upper end of the support rod 7, and a sample 10 is accommodated on the sample stage 9. A heat equalizing cylinder 12 made of, for example, platinum is arranged around the support rod 7, and a lid 13 that covers the sample 10 from above is placed on the upper end of the heat equalizing cylinder 12. This lid 13 is also made of platinum.

The heater 5 generates heat based on a predetermined program, which increases the temperature of the sample 10 in the sample table 9. Due to this temperature rise, the sample 10 undergoes a thermal change,
For example, when gas generation occurs, the weight of the sample 10 changes. This weight change is measured by the balance mechanism 6 by a known method.

A gas transfer tube for transporting gas generated from the sample 10 to the mass spectrometer 2 between the protective tube 3 and the mass spectrometer 2
16 are installed. The gas transfer tube 16 is formed by a capillary glass tube 14 extending from a position directly above the sample 10 to the space between the mass spectrometers 2 through the lid 13 and a covering tube 15 covering the capillary glass tube 14. It is configured. The tip of the coating tube 15 on the side of the protection tube 3 extends to the inside of the protection tube 3, that is, a region that can be heated by the heater 5.

The capillary glass tube 14 is formed of a material made of a material that does not easily change the gas, such as quartz glass, and has an extremely small inner diameter, for example, about 0.1 mm to 0.6 mm. The cladding tube 15 is formed of a metal having good heat conductivity, for example, stainless steel.

Above the protection tube 3, a carrier gas introduction mechanism 17 is provided. As shown in FIG. 2, the carrier gas introduction mechanism 17 includes a transfer tube-side glass tube 19 having a tapered portion 18 having a conical outer peripheral surface, and a carrier tube 3 joined to the upper end of the transfer tube-side glass tube 19. It is constituted by a directional branch pipe 20 and a sealing member 21 joined to an upper end of the branch pipe 20. A gas supply pipe 22 communicating with a carrier gas supply source (not shown) is connected to the intake port 20a of the three-way branch pipe 20.
Further, appropriate gaps G are provided between the inner wall of the branch pipe 20 and the coating pipe 15 of the gas transport pipe 16 and between the transport pipe-side glass pipe 19 and the coating pipe 15.

The gas supply pipe 22 feeds a gas having a relatively small molecular weight, for example, helium (He) gas into the branch pipe 20 as a carrier gas through the intake port 20a. The carrier gas sent in flows downward through the gap G, and enters the protective tube 3.
Flows into the protection tube 3 from above. Because of the sealing member 21, the carrier gas does not flow upward in the figure.

As described above, when the temperature of the sample 10 disposed in the protective tube 3 changes, gas is generated from the sample 10 according to the properties of the sample 10. This generated gas is sent into the capillary glass tube 14 by the carrier gas sent into the protective tube 3. Thereafter, the generated gas is transported in the capillary glass tube 14 by the carrier gas, and is sent to the mass spectrometer 2 shown in FIG.

In this embodiment, the mass spectrometer 2 is constituted by a so-called quadrupole mass spectrometer. The mass spectrometer 2 has a vacuum case 23 in which the inside is kept in a vacuum, and an ion source 24, a quadrupole
25, and each component of the ion detector 26 is provided.

The generated gas sent through the capillary glass tube 14 on the carrier gas is first sent to the ion source 24,
In the ion source 24, a gas component constituting the gas is ionized. In this case, the charge of the ionized gas component has a unique value corresponding to the mass number of the gas component, that is, the type of gas. The ionized gas component then passes within the electric field formed by the quadrupole 25. At this time, the gas component proceeds while drawing a curvature according to the electric charge of the gas component.

When the generated gas is a specific type of gas to be measured, the gas component passing through the quadrupole 25 is detected by the ion detector 26. On the other hand, when the gas component passing through the quadrupole 25 is not such a specific one, the traveling curve of the gas component in the quadrupole 25 deviates from the traveling path toward the ion detector 26, and as a result, the ion The detector 26 does not detect the gas component. Thus, depending on whether or not the ionized gas component is detected by the ion detector 26, the gas sent to the ion source 24, that is, from the sample 10 in the protection tube 3, The type of gas generated is identified.

By the above-described processing performed by the TG device 1 and the mass spectrometer 2, the mass change measurement (thermogravimetry) with respect to the temperature change of the sample 10 and the identification of the gas generated from the sample are performed.

As is clear from the above description, in this embodiment, the gas generated from the sample 10 placed in the protective tube 3 is
It is carried to the mass spectrometer 2 by a capillary glass tube 14. Since glass has extremely low catalytic ability to gas as compared with metal, gas generated from the sample 10 can be transported to the mass spectrometer 2 without altering. Therefore, the generated gas can be accurately identified. In this case, if quartz glass is used as the constituent material of the capillary glass tube 14, the generated gas can be more reliably prevented from being altered.

The capillary glass tube 14 is an extremely thin tube having an inner diameter of about 0.1 mm to 0.6 mm, and extends to a position immediately above the sample 10. The extremely small inner diameter of the capillary glass tube 14 means that the gas flowing therethrough is extremely fast, which means that when gas is generated from the sample 10, the generated gas is very instantaneously. That is, the gas is sent to the mass spectrometer 2 and the generated gas is identified. As a result, the thermogravimetric measurement by the balance mechanism 6 and the generated gas analysis by the mass spectrometer 2 can be performed in so-called real time.

By the way, O ₂ , H _{2 which} should not be conveyed to the mass spectrometer 2 in the lower part inside the protection tube 3
O Many other so-called background components (components that hinder the analysis of generated gas) are accumulated in large amounts. This is because auxiliary equipment such as the weight measurement unit 4 is attached below the protection tube 3.

In this embodiment, the carrier gas introduction mechanism 17 is provided above the protection tube 3 and the carrier gas is supplied to the protection tube 3.
Is introduced into the interior from the top of the Therefore, only the gas generated from the sample 10 can be carried into the capillary glass tube 14 by the carrier gas without including the background component accumulated at the bottom of the protective tube 3. Therefore, highly accurate gas analysis can be performed by the mass spectrometer 2.

In FIG. 2, in a portion from the carrier gas introduction mechanism 17 to the top of the protective tube 3, the carrier gas sent from the gas supply tube 22 flows downward in the gap G, while being generated from the sample 10. The gas flows upward in the capillary glass tube 14 together with the carrier gas. Since the gap G and the capillary glass tube 14 are both extremely thin, if the temperature of the portion becomes lower than an allowable limit, the gap G or the capillary glass tube 14 may be clogged with the gas or gas that has been formed into droplets.

On the other hand, in this embodiment, the cladding tube 15 is formed of a material having good thermal conductivity such as stainless steel, and the tip of the cladding tube 15 is extended to the inside of the protection tube 3, that is, to the region heated by the heater 5. Therefore, the region from the carrier gas introduction mechanism 17 to the top of the protective tube 3 is always warmed by the cladding tube 15 heated to a high temperature by heat conduction.
Therefore, clogging of the gap G or the like due to the above-described droplet can be prevented, and the carrier gas and the gas generated from the sample can always flow smoothly.

In this embodiment, the carrier gas introduction mechanism 17
The lower part of the transfer-tube-side glass tube 19 is formed as a tapered portion 18 having a shape narrowing downward. on the other hand,
A protective tube-side glass tube having an inverted tapered inner peripheral surface whose diameter gradually increases upward at the upper part of the protective tube 3.
27 are formed. Both the tapered portion 18 and the protective tube-side glass tube 27 can be fitted so that they are in surface contact with each other.On the other hand, by pulling the transfer tube-side glass tube 19 upward in the drawing, They can be separated from each other. If both are separated, the gas transfer pipe 1
6, that is, the capillary glass tube 14 and the cladding tube 15
It moves together with 8 and is removed to the outside of the protection tube 3.

In the current thermal analysis measurement, the mass spectrometer 2 is connected to the sample 10 as in the above-described embodiment, or a gas chromatography device is connected instead of the mass spectrometer 2, or When performing only physical measurements such as thermogravimetry without connecting,
There are various measurement modes.

As in the present embodiment, the connection between the protection tube 3 and the gas transfer tube 16 is performed only by a simple operation of simply fitting the tapered portion 18 and the protection-tube-side glass tube 27 having an inverted taper shape. If this is the case, it is possible to extremely easily change the parts of the apparatus when performing the thermal analysis measurement in various different modes as described above.

The present invention has been described based on the illustrated embodiment.
The present invention is not limited to the embodiment.

For example, in the embodiment, the mass spectrometer 2 has been described as an example of the device having the generated gas analysis function, but any other gas analyzer can be used.

Also, a method of introducing a carrier gas into the protective tube 3 is as follows.
Any other configuration can be adopted as long as the function of introducing the carrier gas from the upper portion of the protection tube 3 into the inside thereof is achieved.

[Effects of the Invention] According to the first aspect of the present invention, the gas generated from the sample (10) is transported by the glass tube, so that the generated gas can be guided to the gas analyzer without altering the quality.

In addition, since a capillary tube with an extremely small inner diameter is used, the flow velocity of the generated gas flowing in the tube can be increased, and the thermal analysis measurement such as thermogravimetry and the generated gas analysis have almost no time difference, so-called real time. It can be carried out.

According to the second aspect of the present invention, both the cladding tube (15) and the capillary glass tube (14) are warmed, and the inside and the outer periphery of the tube do not become clogged with droplets of gas. In this case, the capillary glass tube is heated by the cladding tube, and the cladding tube is warmed by the heater (5) for heating the sample. Therefore, it is not necessary to provide a dedicated heater for heating them, which is very economical and can save space for disposing the dedicated heater.

[Brief description of the drawings]

FIG. 1 is an overall schematic view showing one embodiment of a thermal analyzer having a generated gas analysis function according to the present invention, and FIG. 2 is a cross-sectional view showing a main part of the embodiment. 2 ... mass spectrometer, 3 ... protective tube, 5 ... heater, 9
…… Sample stage, 10 …… Sample, 14 …… Capillary glass tube, 15 ……
Cladding tube, 16 Gas transport tube, 18 Tapered portion, 19 Glass tube on transfer tube, 27 Glass tube on protection tube

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-219540 (JP, A) JP-A-61-213655 (JP, A) JP-A-59-17133 (JP, A) JP-A-62 268201 (JP, A) JP-A-61-106339 (JP, A) JP-A-2-272357 (JP, A) JP-A-63-14155 (JP, U) JP-A-49-95993 (JP, U) Shokai 61-193281 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01N 25/20 G01N 27/62

Claims (2)

(57) [Claims] 1. A protective tube for shielding a sample stage on which a sample is mounted from the outside, a gas analyzer for analyzing gas generated from the sample, and a gas analyzer for converting gas generated from the sample by a carrier gas. A thermal analysis apparatus having a generated gas analysis function having a gas transport pipe for transporting the gas to the gas analyzer, wherein the gas transport pipe comprises: a capillary glass tube provided from the position immediately above the sample in the protective tube to the gas analyzer; A thermal analysis device comprising: a glass tube; and a coating tube coated around the glass tube. 2. The thermal analyzer according to claim 1, wherein a heater for heating a sample is provided around the protective tube, and the cladding tube is made of a material having thermal conductivity. A thermal analyzer characterized in that at least a part of the cladding tube is heated by the sample heating heater.