JPH0587753A - Thermal analyzer - Google Patents

Abstract

PURPOSE:To enable a thermal analyzer to perform thermal analysis as it is after a quenching process, such as uncrystallization, etc. CONSTITUTION:A coolant passage 31 for directly sprinkling a liquid or gaseous coolant 33 upon a sample holder 34 or a sample 35 put in the holder 11 is formed through a sampling heater/cooler 30 covering the periphery of the sample holder 34. Therefore, the cooling condition of the sample 35 can be fixed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal analyzer such as a differential thermal analyzer or a differential scanning calorimeter which is a material analyzer utilizing heat.

[0002]

2. Description of the Related Art Differential Thermal Analysis
The lysis = DTA) device is a device for investigating the thermal characteristics of the sample by measuring the temperature difference ΔT between the sample and the reference substance as a function of the temperature T while changing the temperature of the sample and the reference substance at a constant rate. In addition, differential scanning calorimetry (Differenti
al Scanning Calorimetry = DSC) is a device that measures the difference ΔQ in energy input to the sample and the reference substance as a function of the temperature T while changing the temperature of the sample and the reference substance at a constant speed.

An outline of the differential scanning calorimeter will be described with reference to FIG. A thin plate 50 acting as a heat passage is laid over a cavity inside a sample holder 34 made of a good heat conductor such as silver, and a sample 3 stored in a container made of aluminum or the like thereon.
5 and reference material 36 are placed. Thermocouples 51 and 52 such as chromel (C) -alumel (A) are attached to the thin plates 50 below the sample 35 and the reference material 36, respectively.
The thin plate 50 is made of a suitable metal (Constantan C in the example of FIG. 3).
If prepared in step t), the temperature difference ΔT between the sample 35 and the reference substance 36 is measured by measuring the potential difference between the same metal wires (C in the example of FIG. 2) of both thermocouples 51 and 52. Can be detected by. The temperature T of the sample 35 is of course detected by the thermocouple 51.

A sample holder 3 is provided with a sample 35 and a reference substance 36.
4 and by closing the lid 38, gradually heating or cooling the entire sample holder 34, and continuously measuring the sample temperature T and the temperature difference ΔT between the sample and the reference material during that period, The heat change occurring in the sample can be detected by the baseline shift and the endothermic / exothermic peaks.

[0005]

The samples for which thermal analysis is performed cover a wide range regardless of whether they are inorganic substances or organic substances, but in some cases information about the aggregated state of the molecules can be obtained. For example, if a metal or polymer resin originally having a crystal structure is heated to a high temperature and then cooled at a very high speed, it does not crystallize,
It solidifies (vitrifies) in a disordered (amorphous) state similar to liquid. Normally, even if the same substance is used, the crystalline state and the amorphous state have different thermal properties, so it is necessary to compare the thermal analysis data of both.

In such a case, conventionally, the sample was melted at a place different from the thermal analyzer and cooled on a metal block immersed in the cooling liquid, or the sample together with the container was immersed in the cooling liquid to be made amorphous. .. However, it is not only operationally complicated to separately perform the pretreatment for sample preparation and the subsequent thermal analysis as described above, but such a method can realize a reproducible cooling process. Often difficult.

The present invention has been made in order to solve such a problem, and its object is to perform a thermal analysis immediately after performing a cooling treatment such as amorphization. It is to provide a thermal analysis device.

[0008]

According to the present invention, which has been made to solve the above-mentioned problems, in a thermal analysis apparatus equipped with a sample heating / cooling device that covers the periphery of a sample, a liquid or gas cooling medium is provided in the sample. A cooling medium passage for hanging is provided.

The sample heating / cooling device referred to here includes a device that performs only heating or only cooling. In the case where the sample is surrounded by a sample holder made of a good thermal conductor such as a differential scanning calorimeter and heat is exchanged through the sample holder, liquid or gas is passed through the sample holder. The cooling medium may be applied.

[0010]

After the sample is put in the container, the sample is heated by the sample heating / cooling device to melt the sample. afterwards,
The heating by the sample heating / cooling device is stopped, and the liquid or gas cooling medium is immediately applied through the cooling medium passage. At this time, when it is desired to increase the cooling rate of the sample very much, the liquid cooling medium is applied to the sample or the sample holder at a large flow rate.
Immediately after the pretreatment of the sample by rapid cooling is completed, the sample is heated by the sample heating / cooling device according to a predetermined temperature program, and the sample is subjected to thermal analysis.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As an embodiment of the present invention, a differential scanning calorimeter will be described with reference to FIG. In this embodiment, the device for cooling the sample is composed of a cover 30 made of a heat insulating material, and an upper pipe 31 and a lower pipe 32 attached to the heat insulating cover 30. The cover 30 may be a mirror-finished double glass container or a metal double-walled container (so-called thermos type heat insulating container) having a vacuum space formed therein.

The heat insulating cover 30 is placed on the bottom plate 35 below the sample holder 34 so as to cover the sample holder 34 of the differential scanning calorimeter. Thereby, the heat insulating cover 30
The inside of is isolated from the outside. The upper pipe 31 is provided at the center of the upper portion of the heat insulating cover 30 so as to penetrate the heat insulating cover 30, and the lower pipe 32 is provided at the lower side wall of the heat insulating cover 30 so as to also penetrate the heat insulating cover 30. There is.

The sample 35 and the reference substance 36 are respectively housed in a container made of aluminum or the like, and both are placed inside the sample holder 34 of the differential scanning calorimeter. The sample holder 34 is provided with a lid 38 that can be opened and closed from the outside of the heat insulating cover 30. In the example of FIG. 1, the lid 38 is a cord 39.
The sample holder 34 is opened by pulling, and the upper part of the sample holder 34 is covered by its own weight by releasing the string 39. Both the sample holder 34 and the lid 38 are made of a good heat conductor such as silver.
In this embodiment, the sample 35 (and the reference material 36) is heated by the heater 40 wound around the outer periphery of the sample holder 34. A thermocouple, a lead wire 42 of the heater 40, and the like are connected between the sample holder 34 and the controller 41 of the differential scanning calorimeter.

When a differential scanning calorimetric analysis apparatus having the above-mentioned structure is used to perform differential scanning calorimetric analysis in the amorphous state of a resin substance, first, the resin substance sample is placed in the sample container of the sample holder 34. Then, it is heated to a temperature higher than the melting point by the heater 40. Then, the string 39 is pulled to open the lid 38, and the liquefied cooling medium (for example, liquid nitrogen) 33 is hung on the sample 35 from the upper pipe 31. Normal,
Since the cooling rate must be very high in order to make the substance amorphous, it is desirable to make the upper pipe 31 thick so that a large amount of the liquefied cooling medium can be applied to the sample 35 all at once. In addition, the cooling medium 33 that has been vaporized on the sample 35 is discharged from the lower pipe 32 to the outside of the heat insulating cover 30.

Immediately after the amorphization of the sample 35, the string 39 is released to cover the sample holder 34, and the control by the controller 41 of the differential scanning calorimeter is started. In this differential scanning calorimetry, sample 3
When heating 5, the heater 40 around the sample holder 34
When the sample 35 is cooled by using, the vaporized cooling medium (nitrogen gas or the like) is introduced from the lower pipe 32. At this time, the cooling medium gas after cooling the sample 35 is discharged from the upper pipe 31 to the outside.

Another embodiment of the present invention will be described with reference to FIG. Although this embodiment is also related to the differential scanning calorimeter, a complicated sample cooling device 10 is provided to cool the sample more efficiently. This sample cooling device 10
Is composed of a cooling unit 12 and a control unit 13. The cooling unit 12 has a double structure composed of an outer shell 18 and an inner shell 19, and a liquefied cooling medium 21 is filled between them. Less than,
The sample cooling device 10 will be described in detail.

The cooling unit 12 has an outer shell 18 that opens at the bottom.
And the inner shell 19 that is inside the outer shell and also opens at the bottom
And a bottom plate 22 for connecting the two at the bottom to form a closed space 20 between the inner and outer shells. A heat insulating material is used for the outer shell 18 and the bottom plate 22. A mirror-finished double glass container or a metal double-walled container (so-called thermos type heat insulating container) having a vacuum space formed therein may be used. Inner shell 19
It is not necessary to use a heat insulating material. Rather, as described below, in some cases it is preferable to use a good thermal conductor to cool the sample.

A supply port 23 for supplying a liquefied cooling medium 21 such as liquid nitrogen into the closed space 20 is provided on the upper side surface of the outer shell 18. Further, inside the closed space 20, a cooling gas delivery pipe having one opening at a position higher than the normal liquid surface level of the liquefied cooling medium 21 and the other opening inside the inner shell 19 (sample side). 24 is provided. Furthermore, the inner and outer shells 19, 18
And the inside of the inner shell 19 and the outer shell 18 through the closed space 20.
An upper pipe 25 is provided which communicates with the upper part of the. The upper pipe 25 is branched outside the outer shell 18 into a discharge port 43 to the atmosphere via a switching valve 44 and a pipe 45 communicating with a cooling medium tank 14 described later.

At a position below the normal liquid level of the liquefied cooling medium 21 in the closed space 20, a liquid level detection sensor 26 is provided.
To provide. When the liquid surface level of the liquefied cooling medium 21 in the closed space 20 drops below the position of the sensor 26, the sensor 26 sends a signal to that effect to the control unit 13. Similarly, a heater 27 for heating and vaporizing the liquefied cooling medium 21 is provided at a position below the normal liquid level of the liquefied cooling medium 21 in the closed space 20. The heater 27 is controlled by a controller (not shown) of the differential scanning calorimeter.

An external liquefied cooling medium tank 14 is connected to the supply port 23 of the cooling unit 12 via a pump 16. The pump 16 is controlled by the control unit 13 of the sample cooling device 10, and supplies the liquefied cooling medium 15 in the tank to the closed space 20 of the cooling unit 12 in an arbitrary amount at an arbitrary time, or
The sample is directly hung through the upper tube 25. In addition, pump 1
Reference numeral 6 is a mere transport means, and various devices such as a heater pressurizing type siphon can be used.

A switching valve 46 is provided between the pump 16 and the supply port 23, and the switching of the valve 46 causes the flow of the liquefied cooling medium 15 in the tank 14 to flow to the supply port 23 through a pipe 47 and an upper pipe 25. It is distributed to the pipe 45 to. Further, a switching valve 48 is also provided on the outside of the supply port 23, and the connection is switched to a discharge port 49 to the atmosphere and a pipe 47 to the tank 14.

When the sample holder 11 is slowly cooled in the differential scanning calorimeter of this embodiment, the controller (not shown) of the differential scanning calorimeter measures the sample cooling device 1.
An electric current is passed through the heater 27 inside the cooling unit 12 of 0. As a result, the heater 27 is heated and the closed space 20 of the cooling unit 12 is heated.
The liquefied cooling medium 21 (liquid nitrogen or the like) held therein is vaporized. The vaporized cooling medium 28 fills the space above the closed space 20 and is further sprayed onto the sample holder 11 inside the inner shell 19 through the cooling gas delivery pipe 24. Since the amount of the cooling medium gas 28 blown to the sample holder 11 changes depending on the heating amount of the heater 27, the controller of the thermal analysis device that controls the energization amount of the heater 27 can control the cooling rate of the sample. You can do it.

The cooling medium gas 28 sprayed onto the sample holder 11 is operated by the switching valve 44 to operate the upper pipe 25.
And is discharged to the outside through the discharge port 43. Further, the amount of the liquefied cooling medium 21 in the closed space 20 of the cooling unit 12 decreases,
When the liquid level falls below the level of the liquid level detection sensor 26, a signal is sent from the sensor 26 to the control unit 13, and the control unit 13 drives the pump 16. This allows the tank 1
The liquefied cooling medium 15 in the cooling unit 4 passes through the supply port 23 and the cooling unit 1
2 is supplied. By this control mechanism, the amount of the liquefied cooling medium 21 in the closed space 20 of the cooling unit 12 is always kept constant.

As described above, in the sample cooling device 10 according to the present embodiment, the cooling medium gas is blown onto the sample (sample holder 11) immediately after being vaporized, and the cooling gas delivery pipe 24 itself is liquefied cooling medium. Since it passes through 21, the cooling medium gas blown to the sample is at a low temperature that is almost the boiling point temperature. Furthermore, if a good heat conductor is used for the inner shell 19 as described above, a cooling effect by gas conduction through the inner shell 19 and the gas layer around the sample holder 11 can also be obtained.

On the other hand, when it is necessary to rapidly cool the sample in the sample holder 11 to make it amorphous, etc., the pump 16 is operated by operating the switching valves 46 and 44.
The liquefied cooling medium from the above is flowed toward the upper tube 25. As a result, the liquefied cooling medium 29 is applied directly to the sample holder 11 (or directly to the sample when the lid is opened) as in the above-described embodiment, and the sample is rapidly cooled. The cooling medium that has been vaporized by being placed on the sample holder 11 enters the closed space 20 through the cooling gas delivery pipe 24, and is further discharged to the outside from the supply port 23 and the atmospheric emission port 49 by the operation of the valve 48. It

It is convenient that the switching valves 44, 46 and 48 used in the second embodiment are all electromagnetic valves which are automatically switched by a command from the control device. Further, in each of the above two embodiments, the differential scanning calorimetry device is mentioned as the thermal analysis device, but the present invention can be applied to other thermal analysis devices such as the differential thermal analysis device in the same manner.

[0027]

In the thermal analyzer according to the present invention, the thermal analysis can be started immediately without any time after the pretreatment for rapidly cooling the sample such as the preparation of the amorphized sample. Further, since it becomes possible to strictly control the supply of the cooling medium, it becomes possible to perform heat treatment with good reproducibility in the rapid cooling and amorphization. Furthermore, thermal analysis can be performed after adding an arbitrary thermal history to the sample with the sample heating / cooling device, including slow cooling using the cooling medium passage,
It allows for the analysis of a wider range of properties of the sample.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the structure of a differential scanning calorimeter according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the structure of a sample cooling device of a thermal analysis device which is a second embodiment of the present invention.

FIG. 3 is a sectional view showing the structure of a differential scanning calorimeter.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Sample cooling device 11 ... Sample holder 12 ... Cooling part 13 ... Control part 18 ... Outer shell 19 ... Inner shell 25 ... Upper pipe (cooling medium passage) 29 ... Liquefied cooling medium 30 ... Insulating cover (sample heating / cooler) 31 ... Upper pipe (cooling medium passage) 34 ... Sample holder

Claims (1)

[Claims] 1. A thermal analysis device comprising a sample heating / cooling device for covering the periphery of a sample, wherein a cooling medium passage is provided for applying a liquid or gaseous cooling medium to the sample.