JP2021039062A - Thermal analysis device - Google Patents

Abstract

To reduce the workload of atmosphere replacement.SOLUTION: A thermal analysis device includes a heating furnace 10 in which a sample to be measured is housed, a heating control unit 3 that controls the heating of the furnace, a gas supply unit 2 that supplies a predetermined gas to the inside of the furnace, a measurement condition setting unit 50 that allows a user to set measurement conditions including a temperature profile that shows a relationship between passage of time and temperature, an atmosphere substitution condition setting unit 51 that allows the user to set atmosphere substitution conditions including a type of gas to be used, a gas flow rate, substitution time, and stabilization waiting time during atmosphere substitution prior to measurement. and control units 4, 5, which control the gas supply unit and the heating control unit according to the measurement conditions set by the measurement condition setting unit to measure a sample after the atmosphere in the heating furnace is replaced by controlling the gas supply unit according to the atmosphere substitution conditions set by the atmosphere substitution condition setting unit upon receiving instructions from the user.SELECTED DRAWING: Figure 1

Description

The present invention relates to a thermal analyzer such as a differential thermal analyzer (DTA), a thermogravimetric analyzer (TGA), a thermomechanical analyzer (TMA), a differential scanning calorimetry (DSC), and the like.

There are various methods for thermal analysis such as differential thermal analysis, thermogravimetric analysis, thermomechanical analysis, and differential scanning calorimetry. For example, differential thermal analysis is a method of measuring the temperature difference between a sample and a reference material as a function of temperature while changing the temperature of the sample and the reference material according to a certain program. For example, transfer, melting, reaction, etc. Phenomena accompanied by heat absorption are the objects of measurement. The thermal weight measurement is a method of measuring a change in the weight of a sample when the sample is heated or cooled at a constant rate or held at a constant temperature, and is, for example, evaporation, decomposition, oxidation, or reduction. , Chemical or physical changes accompanied by weight changes with temperature such as adsorption are the objects of measurement. For example, Non-Patent Document 1 discloses an apparatus having both functions of differential thermal analysis and thermogravimetric analysis and capable of performing both measurements at the same time.

In any of these methods, in such a thermal analyzer, the sample is housed inside a heating furnace and heated to a predetermined temperature (for example, about 1500 ° C.), or conversely, cooling is performed from a high temperature state. Analyze the thermal changes that occur in the sample. In order to perform an analysis associated with such a temperature change, in a conventional thermal analyzer, a user sets in advance a measurement program including a temperature profile showing the temperature change with the passage of time using a personal computer connected to the apparatus. When the user instructs the start of measurement, heating or cooling is automatically executed according to the set measurement program.

In such a thermal analyzer, when the measurement is performed without oxidizing the sample, in order to remove the oxidizing gas such as oxygen in the heating furnace, the gas inside the heating furnace is changed to an inert gas such as nitrogen before the start of measurement. It is necessary to perform the work of replacing with (see Patent Document 1 and the like). As the gas used for this atmosphere replacement, helium, argon, or the like may be used in addition to nitrogen or the like, depending on the purpose of measurement.

Japanese Unexamined Patent Publication No. 8-152419 (paragraphs [0014]-[0015])

"DTG-60 / 60H Series TG / DTA Simultaneous Measuring Device", [online], Shimadzu Corporation, [Search on August 13, 2019], Internet <URL: https://www.an.shimadzu.co. jp / ta / dtg60.htm ＞

In the conventional thermal analyzer, the measurement itself is automatically performed according to the measurement program, but the work of replacing the atmosphere before the measurement must be performed manually by the user. Therefore, the operator must not only operate the flow valve for supplying the inert gas, but also wait until the atmosphere in the heating furnace is sufficiently replaced with the inert gas, and then start the measurement. It is necessary to perform the operation for. The involvement of the operator in such work reduces the measurement efficiency, and may cause the operator to make a mistake such as starting the measurement even though the atmosphere replacement is insufficient.

The present invention has been made to solve the above problems, and its main purpose is to reduce the burden on the operator (user) at the time of measurement, improve the efficiency of measurement work, and cause inconvenience due to work mistakes. It is to provide a thermal analyzer that can prevent the execution of appropriate measurements.

The thermal analyzer according to one aspect of the present invention, which has been made to solve the above problems, includes a heating furnace in which a sample to be measured is housed, a heating control unit for controlling heating of the heating furnace, and the above. A thermal analyzer including a gas supply unit that supplies a predetermined gas to the inside of a heating furnace.
A measurement condition setting unit that allows the user to set measurement conditions including a temperature profile that shows the relationship between the passage of time and temperature.
An atmosphere replacement condition setting unit that allows the user to set the atmosphere replacement conditions including the type of gas to be used, the flow rate of the gas, the replacement time, and the stabilization waiting time at the time of atmosphere replacement performed prior to the measurement.
In response to a user's instruction, the gas supply unit is controlled according to the atmosphere replacement condition set by the atmosphere replacement condition setting unit to replace the atmosphere in the heating furnace, and then the measurement condition setting unit is subsequently used. A control unit that controls the gas supply unit and the heating control unit to perform measurement on the sample according to the measurement conditions set by
Is provided.

The measurement condition setting by the measurement condition setting unit and the atmosphere replacement condition setting by the atmosphere replacement condition setting unit may be executed substantially simultaneously (that is, together), or may be executed individually. May be good.

In the thermal analyzer of the above aspect of the present invention, the measurement condition and the atmosphere replacement condition are appropriately set in advance by the user, so that the atmosphere replacement operation and the measurement in the heating furnace can be performed only by instructing the start of measurement, for example. It is possible to automatically execute a series of operations. As a result, the operator does not need to operate the gas flow rate valve for atmosphere replacement, and does not need to wait until the atmosphere replacement is completed. According to the thermal analyzer of the above aspect of the present invention, it is possible to reduce the burden on the operator in the measurement, improve the efficiency of the measurement work, and prevent the execution of inappropriate measurement due to the work error. it can.

The block diagram of the main part of the differential thermal analyzer which is one Embodiment of this invention. The figure which shows an example of the time change of the gas flow rate in the differential thermal analyzer of this embodiment.

Hereinafter, the differential thermal analyzer according to the embodiment of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a block diagram of a main part of the differential thermal analyzer of the present embodiment.

The differential thermal analyzer of the present embodiment includes a heating unit 1, an atmosphere gas supply unit 2, a heating control unit 3, an analysis control unit 4, a control unit 5, an input unit 6, and a display unit 7. The heating unit 1 includes a substantially cylindrical heating furnace 10 in which the sample S and the reference material R are housed, a radiation shield 11 surrounding the heating furnace 10, and a heat insulating cover 12 surrounding the radiation shield 11. The heating furnace 10 is made of a heat-resistant material, typically ceramic. A heater wire 10a is wound around the heating furnace 10, and the heating furnace 10 is heated by supplying a heating current from the heating control unit 3 to the heater wire 10a. Further, a gas introduction pipe 14 for introducing a predetermined gas is connected to the heating furnace 10.

The weights of the sample S and the reference substance R are measured by a weight measuring unit (not shown). Further, the temperature difference between the sample S and the reference substance R is also detected by a thermocouple or the like (not shown).

The atmospheric gas supply unit 2 is prepared by the user, has two gas supply sources (gas cylinders, etc.) 20 and 21 connected to the two gas supply ports 22 and 23, respectively, and two autoflows that adjust the flow rate of each gas. Includes controllers (AFC) 24, 25. The control unit 5 includes a measurement condition setting unit 50, an atmosphere replacement condition setting unit 51, a measurement program storage unit 52, and an atmosphere replacement condition storage unit 53.

The analysis control unit 4 is integrated with the heating unit 1, the heating control unit 3, and the like, and is mainly composed of a microcomputer including a CPU, a ROM, a RAM, a timer, and the like. On the other hand, the substance of the control unit 5 is a general-purpose personal computer (PC), and each of the above functions is realized by operating the control / processing software installed on the PC on the PC. be able to.

Next, the operation / work by the user and the operation of the device when the measurement is performed using the differential thermal analyzer of the present embodiment will be described. FIG. 2 is a diagram showing an example of time change of gas flow rate.
The sample S and the reference substance R to be measured are respectively placed on the mounting plate on the upper part of the detector 13 in a state where the heating furnace 10 is raised by a mechanism (not shown). When the sample S and the reference substance R are set, the heating furnace 10 is lowered, and the sample S and the reference substance R are contained therein.

When the operator performs a predetermined operation on the input unit 6, the atmosphere replacement condition setting unit 51 first causes the operator to input the type of gas connected to the two gas supply ports 22 and 23 as the initial environment setting. .. Normally, the type of gas used for thermal analysis is fixed, not limited to the purpose of atmosphere replacement, so an option to select the gas type is prepared and connected to each gas supply port 22 and 23, respectively. The type of gas may be selected by the operator. If the type of gas connected to the gas supply ports 22 and 23 is not changed, this setting process can be omitted.

When the operator further performs a predetermined operation on the input unit 6, the atmosphere replacement condition setting unit 51 displays the atmosphere replacement condition setting screen of a predetermined format on the display unit 7 and causes the operator to input the atmosphere replacement condition. The atmosphere replacement conditions include the type of gas used for atmosphere replacement, the gas flow rate La, the replacement time ta, the device stabilization waiting time tb, and the like.

Since the gas type can be selected only from the two types of gas connected to the gas supply ports 22 and 23, the two types of gas set in the previous environment setting are presented to the operator as options, and the gas type is presented to the operator. The operator may be allowed to select either one. The gas flow rate La is the flow rate of the gas to be introduced into the heating furnace 10 at the time of atmosphere replacement, and the operator may be allowed to input a numerical value. The replacement time ta is a time during which the gas having the gas flow rate La is continuously introduced into the heating furnace 10 at the time of atmospheric replacement, and the operator may be allowed to input a numerical value. The device stabilization waiting time tb is a time for waiting for the device to become stable in a state where the flow rate of the gas introduced into the heating furnace 10 is changed to the gas flow rate at the time of measurement after the completion of the replacement time ta. , This can also be entered numerically by the operator.

Generally, nitrogen is widely used as the gas for atmosphere replacement, but other inert gases such as helium and argon may also be used. Further, the numerical values such as the gas flow rate differ depending on the size of the heating furnace 10, etc., but as a typical example of the thermal analyzer described in Non-Patent Document 1, the gas flow rate is 300 mL / min, the replacement time is 30 min, and the device is stable. The waiting time for conversion can be set to about 3 min.
When the input setting of the atmosphere replacement condition is confirmed, the atmosphere replacement condition setting unit 51 temporarily saves the set atmosphere value replacement condition as a file in the atmosphere replacement condition storage unit 53.

When the operator also performs another predetermined operation on the input unit 6, the measurement condition setting unit 50 displays the measurement condition setting screen in a predetermined format on the display unit 7 and causes the operator to input the measurement replacement condition. The measurement conditions are a temperature profile showing the relationship between elapsed time and temperature, the type of gas used during measurement (however, it is not limited to one type, and the type of gas may be switched during measurement), and the gas flow rate La. And so on. As with the case of atmosphere replacement, the gas type can be selected only from the two types of gas connected to the gas supply ports 22 and 23, so the two types of gas set in the previous environment settings are selected as options. It may be presented to the worker and one of them may be selected by the worker. The gas flow rate Lb is the flow rate of the gas to be introduced into the heating furnace 10 at the time of measurement, and the operator may be allowed to input a numerical value. For example, when the gas flow rate at the time of atmosphere replacement is 300 mL / min as described above, the gas flow rate at the time of measurement is about 50 mL / min.

When the input setting of the measurement condition is confirmed, the measurement condition setting unit 50 temporarily saves the set measurement condition as a file in the measurement program storage unit 52.
The atmosphere replacement condition and the measurement condition may be input and set on the same setting screen. Further, both conditions may be treated as one and stored in one file.

Further, the measurement for different samples may be repeated without changing the measurement conditions and the atmosphere replacement conditions. In such a case, the measurement conditions and the measurement conditions stored in the measurement program storage unit 52 and the atmosphere replacement condition storage unit 53 are used. Atmosphere replacement conditions can be called and used. As a result, when the measurement conditions and the atmosphere replacement conditions are not changed, or when the measurement conditions and the atmosphere replacement conditions that have been used in the past are used again, the trouble of inputting the parameters and the like can be saved.

When the operator instructs the input unit 6 to start measurement while the measurement conditions and atmosphere replacement conditions to be used have been determined, the control unit 5 analyzes the determined measurement conditions and atmosphere replacement conditions in response to the instruction. Send to 4. First, the analysis control unit 4 controls the operation of the autoflow controllers 24 and 25 in the atmosphere gas supply unit 2 based on the information of the gas type and the gas flow rate La under the atmosphere replacement condition, and heats the heating furnace through the gas introduction pipe 14. Start supplying gas to 10. That is, one of the two autoflow controllers 24 or 25 is selected according to the set gas type, and the gas whose flow rate is adjusted by the selected autoflow controller 24 or 25 is flowed. As a result, as shown in FIG. 2, a predetermined gas is supplied into the heating furnace 10 at a gas flow rate La from the start of replacement, and the gas (air) remaining in the heating furnace 10 before that is discharged to the outside. Begin to be done.

The analysis control unit 4 measures the time with a timer from the start of replacement, and when the replacement time ta elapses, reduces the gas flow rate to the gas flow rate Lb at the time of measurement set as the measurement condition. The analysis control unit 4 measures the time with a timer from the end of the replacement, and starts the measurement according to the measurement program when the device stabilization time tb elapses. Normally, the residual gas in the heating furnace 10 is completely replaced with the atmospheric gas when the replacement time ta has elapsed, and the apparatus stabilization time tb is set by keeping the gas flow rate in the same state as at the time of measurement. It is a period for stabilizing the state such as the flow of gas in 10.

When the measurement is started, the analysis control unit 4 controls the heating control unit 3, for example, in the case of temperature rise analysis, a heating current is supplied to the heater wire 10a, and the temperature of the heating furnace 10 is determined according to the specified temperature profile. To raise. In the process of raising the temperature, the thermal change that occurs in the sample S is detected as the temperature difference between the sample S and the reference substance R. Then, when the measurement according to the measurement program is completed, the heating is stopped and a fan (not shown) is driven to cool the heating furnace 10.

As described above, in the differential thermal analyzer of the present embodiment, after the operator gives an instruction to start the measurement, a series of operations from the start of atmosphere replacement to the end of the measurement is automatically performed without the operator's operation or work. Will be executed. Further, since the atmosphere replacement is automatically executed according to the contents set in advance as the atmosphere replacement condition, it is possible to prevent the occurrence of a problem such as insufficient replacement of the atmosphere if the input setting is properly performed.

In the description of the above embodiment, the control unit 5 sends both the atmosphere replacement condition and the measurement condition to the analysis control unit 4 at the start of measurement, and the analysis control unit 4 controls the operation of each unit thereafter. The operation at the time of atmosphere replacement, that is, the operation of adjusting the gas supply amount in the atmosphere gas supply unit 2, may be configured to be directly controlled by the control unit 5.

Further, usually, the internal volume of the heating furnace 10 is known, and once the gas flow rate at the time of atmosphere replacement is determined, the approximate time required to replace the gas in the heating furnace 10 can be calculated by calculation. Therefore, when the operator inputs the replacement time ta, if the entered numerical value is too small compared to the approximate replacement time required for automatic calculation, a warning is warned that there is a possibility of insufficient replacement. It may be displayed. In addition, the range of numerical values that can be input by the operator may be limited based on the approximate replacement time calculated automatically. As a result, it is possible to prevent an erroneous input operation by the operator.

Further, although the above embodiment is a differential thermal analyzer, the present invention can be applied to other thermal analyzers such as a thermogravimetric analyzer, a thermomechanical analyzer, and a differential scanning calorimetry apparatus. Is clear.

Further, the above embodiment is an example of the present invention, and it is clear that the present invention is included in the claims even if it is further modified, changed or added as appropriate within the scope of the present invention.

[Various aspects]
It will be apparent to those skilled in the art that the exemplary embodiments described above are specific examples of the following embodiments.

(Clause 1) One aspect of the thermal analyzer according to the present invention is a heating furnace in which a sample to be measured is housed, a heating control unit for controlling heating of the heating furnace, and the heating furnace. A thermal analyzer including a gas supply unit that supplies a predetermined gas to the inside.
A measurement condition setting unit that allows the user to set measurement conditions including a temperature profile that shows the relationship between the passage of time and temperature.
An atmosphere replacement condition setting unit that allows the user to set the atmosphere replacement conditions including the type of gas to be used, the flow rate of the gas, the replacement time, and the stabilization waiting time at the time of atmosphere replacement performed prior to the measurement.
In response to a user's instruction, the gas supply unit is controlled according to the atmosphere replacement condition set by the atmosphere replacement condition setting unit to replace the atmosphere in the heating furnace, and then the measurement condition setting unit is subsequently used. A control unit that controls the gas supply unit and the heating control unit to perform measurement on the sample according to the measurement conditions set by
Is provided.

According to the thermal analyzer according to the first item, for example, the atmosphere replacement operation and the measurement operation in the heating furnace can be automatically executed in a series only by the user instructing the start of measurement. As a result, the operator does not need to operate the gas flow rate valve for atmosphere replacement, and does not need to wait until the atmosphere replacement is completed. In this way, it is possible to reduce the burden on the operator at the time of measurement, improve the efficiency of the measurement work, and prevent improper measurement from being executed due to a work error.

(Item 2) The thermal analyzer according to item 1 further includes a measurement condition storage unit that stores the measurement conditions set by the measurement condition setting unit, and the measurement condition setting unit provides the user with measurement conditions. Is set, the measurement conditions already stored in the measurement condition storage unit can be presented, and the measurement conditions can be used as they are as the next measurement conditions.

According to the thermal analyzer described in the second section, when the analysis is performed by reusing the previously used measurement conditions, the user does not need to input and set the measurement conditions to improve the efficiency of the measurement work. Can be done.

(Clause 3) The thermal analyzer according to the first or second paragraph further includes a gas type setting unit for allowing the user to set one or a plurality of gas types prepared in the gas supply unit, and the atmosphere. The replacement condition setting unit and / or the measurement condition setting unit may present the type of gas set by the gas type setting unit to the user as the type of gas that can be used.

According to the thermal analyzer according to the third item, only the types of gas that can be used can be presented to the user, so that it is possible to prevent the user from setting an inappropriate gas type.

(Item 4) In the thermal analyzer according to any one of items 1 to 3, the control unit has a gas type, a gas flow rate, and a replacement time set as the atmosphere replacement conditions. According to, after replacing the atmosphere in the heating furnace with a predetermined gas, the flow rate of the gas is changed to the gas flow rate set as the measurement condition, and then only the stabilization waiting time set as the atmosphere replacement condition is satisfied. You can wait and then perform the measurement.

According to the thermal analyzer described in the fourth item, the measurement can be performed after the gas flow in the heating furnace becomes stable, so that the influence of the unstable gas flow during the measurement can be performed. Can be eliminated and highly accurate measurement can be performed.

1 ... Heating unit 10 ... Heating furnace 10a ... Heater wire 11 ... Radiation shield 12 ... Insulation cover 14 ... Gas introduction pipe 2 ... Atmospheric gas supply unit 3 ... Heating control unit 4 ... Analysis control unit 5 ... Control unit 50 ... Measurement condition setting Unit 51 ... Atmosphere replacement condition setting unit 52 ... Measurement program storage unit 53 ... Atmosphere replacement condition storage unit 6 ... Input unit 7 ... Display unit

Claims (4)

Heat including a heating furnace in which a sample to be measured is housed, a heating control unit for controlling heating of the heating furnace, and a gas supply unit for supplying a predetermined gas inside the heating furnace. It ’s an analyzer,
A measurement condition setting unit that allows the user to set measurement conditions including a temperature profile that shows the relationship between the passage of time and temperature.
An atmosphere replacement condition setting unit that allows the user to set the atmosphere replacement conditions including the type of gas to be used, the flow rate of the gas, the replacement time, and the stabilization waiting time at the time of atmosphere replacement performed prior to the measurement.
In response to a user's instruction, the gas supply unit is controlled according to the atmosphere replacement condition set by the atmosphere replacement condition setting unit to replace the atmosphere in the heating furnace, and then the measurement condition setting unit is subsequently used. A control unit that controls the gas supply unit and the heating control unit to perform measurement on the sample according to the measurement conditions set by
A thermal analyzer equipped with. A measurement condition storage unit for storing the measurement conditions set by the measurement condition setting unit is further provided, and the measurement condition setting unit is already stored in the measurement condition storage unit when the user is made to set the measurement conditions. The thermal analyzer according to claim 1, wherein the measurement conditions are presented and the measurement conditions can be used as they are as the next measurement conditions. A gas type setting unit for allowing the user to set one or a plurality of gas types prepared in the gas supply unit is further provided, and the atmosphere replacement condition setting unit and / or the measurement condition setting unit is provided by the gas type setting unit. The thermal analyzer according to claim 1 or 2, wherein the set gas type is presented to the user as a usable gas type. The control unit replaces the atmosphere in the heating furnace with a predetermined gas according to the type of gas, the flow rate of the gas, and the replacement time set as the atmosphere replacement conditions, and then uses the flow rate of the gas as the measurement condition. The heat according to any one of claims 1 to 3, wherein after changing to the set gas flow rate, waiting for the stabilization waiting time set as the atmosphere replacement condition, and then performing the measurement. Analysis equipment.

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