JPH01170843A - Method and apparatus for thermal analysis and microspectroscopy method - Google Patents

Abstract

PURPOSE:To capture a microscopic change associated to a macroscopic change of the physical properties of a sample by providing a thermal analysis apparatus which makes thermal analysis by changing the temp. of the sample placed on an optical microscope and a spectrophotometer on which the exit light of the microscope is projected. CONSTITUTION:An operator mounts the sample into a sample cell 12A, peeps the sample through an eyepiece lens 24 and changes over an objective lens 16 to an objective 17 after adjusting the vertical position of the objective lens 16. The initial temp. and temp. falling rate of the sample are set with a setter 32 and the initial opening area of an aperture 20 and the micro-opening area at the time of sample scanning are set with a setter 35; the wave number of the exit light of the IR spectrophotometer 26 is initially set according to the sample. Further, an optical path change-over mirror 22 is set as shown in the figure and a controller 34 is started. The macroscopic change of the sample is captured by changing the temp. of the sample placed on the stage 10 of the microscope and making thermal analysis with a photometer 26. The opening of the aperture 20 is set at the micro-opening area under microscopy and the spectral measurement of the micro-area of the sample is executed, by which the microscopic change of the sample is captured in association with the macroscopic change.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application] The present invention relates to a thermal analysis/microscopic spectroscopy method and apparatus for simultaneously performing thermal analysis and spectrum I to spectral measurement under an optical microscope.

[Prior art] Thermal analysis is a method of detecting and analyzing changes in physical properties by changing the temperature of a sample. There is weight analysis, etc.

Infrared spectroscopy is a method of measuring infrared spectra emitted or absorbed by changes in molecular vibration or rotation to analyze molecular structure and the like.

Furthermore, the microscopic analysis method is a method of visually observing temporal and spatial changes in a sample under a microscope to perform analysis.

[Problems to be solved by the invention] However, in the past, the above-mentioned analyzes were not performed on the same sample at the same time. It was not possible to detect microscopic changes.

The present inventors have determined the polymer molding conditions, the curing agent, the glass transition of the polymer, the crystallization, the chemical reaction, the thermal stability, or the phase equilibrium, and the functional group or molecular structure by simultaneously capturing both degrees. We were able to understand the relationship between the two, and found that this would greatly contribute to the development of new polymer materials such as high-melting point plastics.

Based on the above findings, an object of the present invention is to provide a thermal analysis/microscopic spectroscopy method and an apparatus therefor that can capture microscopic changes in relation to macroscopic changes in the physical properties of a sample.

Means for Solving Problem 1] In order to achieve this objective, the thermal analysis/microspectroscopy method according to the present invention performs thermal analysis by changing the temperature of the sample placed on the stage of the microscope. The method is characterized in that macroscopic changes in the sample are captured and microscopic changes in the sample are captured in relation to the macroscopic changes by performing spectrum measurements of microscopic regions of the sample under the microscope.

This thermal analysis is, for example, differential thermal analysis, differential scanning calorimetry, or thermal analysis by capturing changes in the intensity of a specific infrared wavelength of the light emitted from the microscope.

Combinations of thermal analysis and spectral measurements under a microscope include:

■In the process of changing the sample temperature, the sample temperature is kept approximately constant (constant, gradually increasing or gradually decreasing), and in this state, the above microregion is moved to create multiple microregions? Perform roughness spectrum measurement.

The sample temperature is maintained approximately constant in the vicinity where a phase change is detected, for example, by thermal analysis.

(2) The thermal analysis and the spectrum measurement are performed simultaneously while fixing the minute region and raising or lowering the temperature of the sample.

Note that a general analysis may be performed by first performing thermal analysis and spectrum measurement of a minute area without using a microscope, and then the detailed analysis described above may be performed using a microscope.

The thermal analysis/microscopic spectrophotometer according to the present invention is an apparatus for carrying out the method described in 2 above, and includes an optical microscope and a thermal analysis method that performs thermal analysis by changing the temperature of a sample placed on the stage of the optical microscope. The present invention is characterized in that it includes a device and a spectrophotometer into which the light emitted from the optical microscope is input.

This optical microscope is, for example, a scanning optical microscope that is equipped with an aperture that narrows down the field of view and that scans a sample placed on a stage.

[Example] Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a block diagram of a thermal analysis/microspectrophotometer.

In the figure, 10 is an X-Y stage, which is driven in steps of, for example, 5 μm in the X direction of the stage surface and the Y direction perpendicular to this, and 12 is a hot stage,
- A heater 12 placed on the Y stage 10, to which the sample cell 12A is removably attached, and which heats the sample cell 12A.
B and a temperature detector 12C installed inside to detect the ambient temperature of the sample cell 12A, and 14 is a condensing mirror that focuses light from an infrared light source (described later) onto the sample cell 12A and transmits it through the sample. 16 is an objective lens, 17 is a Cassegrain type objective mirror, which is used in place of the objective lens 16 during infrared spectrum measurement, and 18 is a polarizer, which is used when the sample exhibits birefringence. 20 is an aperture whose opening area is, for example, 5 x 5 to 0.
IXO, variable within a range of 1 mm', 22 is an optical path switching mirror that switches the optical path by rotating around an axis at one end, 24 is an eyepiece, and 26 is an infrared spectrophotometer. Something that measures and records spectra, 2
8 is a guiding optical system that focuses the reflected light beam from the optical path switching mirror 22 on the entrance slit of the infrared spectrophotometer 26; 30 is a temperature indicating regulator that collects the temperature detected by the temperature detector 12c; 34 is a controller that controls the power supplied to the heater 12B so that the temperature is raised or lowered according to the conditions set by the setting device 32. The infrared spectrophotometer 26 and the temperature indicating controller 30 are controlled based on the measurement results of the total 26 and the set values from the setting device 35, and the X-Y stage 10 and the a (-Controls the camera 20.

Note that the light source of the infrared spectrophotometer 26 is used as the infrared light source that irradiates the sample with infrared light.

Next, the operation of this embodiment configured as described above will be explained with reference to actual measurement results.

FIG. 2 shows the processing procedure of the controller 34, and FIGS. 3 to 6 show the measurement results.

First, a sample, for example, a polymer molding material, is placed in the sample cell 12A and mounted on the hot stage 12.
4. Look at the sample through the objective lens and adjust the sample position and the vertical position of the objective lens 16. Next, the objective lens 16 is switched to the objective mirror 17. The setting device 32 is operated to set the initial temperature (above the melting point) and cooling rate of the sample.

In addition, by operating the setting device 35, the initial opening area of the aperture 20 and the minute opening area during sample scanning are set, and the output light wave number of the monochromator constituting the infrared spectrophotometer 26 is set according to the type of sample. Initialize accordingly. This wave number is a wave number at which a known main component of the sample exhibits relatively large absorption when crystallized. Furthermore, the optical path switching mirror 22 is brought into the state shown in FIG.

Next, the controller 34 is activated. This allows the second
The process shown in the figure is performed.

That is, in step 100, the X-Y stage I
O is set to the initial position, the opening of the aperture 20 is set to the initial opening area set above, and the wave number of the monochromator of the infrared spectrophotometer 26 is fixed to the initial set wave number.

Note that the temperature of the pot stage I2 is determined by the temperature indication controller 3.
0, the adjustment is made based on the conditions set by the setting device 32.

Next, in step 102, controller 34 reads the light intensity of this fixed wavenumber from infrared spectrophotometer 26.

Next, in step 104, it is determined whether this light intensity is the minimum value, and if it is determined that it is not the minimum value, the process returns to step 102.

Here, polypropylene resin was used as the sample), the fixed wave number was 1450 cm-', the initial temperature of the sample was 200°C,
The measurement results of the light intensity with respect to the sample temperature when the cooling rate was 5°C/min are shown, and the light intensity reached a minimum value at 125°C. Since this temperature varies depending on trace components contained in the sample, an accurate value can only be determined experimentally for each sample.

If an affirmative determination is made in step 104, step 1
The process proceeds to step 06, and a temperature fixing command is supplied to the temperature instruction regulator 30. As a result, the temperature indicating regulator 30 fixes the sample temperature to the detected temperature at this time, regardless of the setting value of the setting device 32. In order to stably perform this fixation, it is necessary to slow down the temperature drop rate.

Next, in step 108, the opening of the aperture 20 is made to have a minute opening area set by the setting device 35. Of course, this opening area is made small in order to determine the infrared spectrum of a minute region of the sample and determine the segregation distribution of the minute components.

Next, in step 110, to scan the sample,
Step drive the XY stage IO.

Next, in step 112, the infrared spectrophotometer 26 is caused to measure an infrared spectrum corresponding to each of the above-mentioned step drives, and the data is stored.

Next, in step 114, it is determined whether the entire scanning range of the XY stage 10 has been scanned, and if the scanning has not been completed, the process returns to step 110.

If it is determined in step 114 that scanning has ended, then in 116 the same processing as in step 100 is performed. This completes all processing by the controller 34.

Next, when the optical path switching mirror 22 was switched for the sample and the sample was looked into through the eyepiece 24, spherulites with boundaries as shown in FIG. 4 were observed. This is a spherulite at the crystallization initiation temperature of polypropylene resin. Among the data stored in the infrared spectrophotometer 26, the difference spectrum obtained by subtracting the infrared absorption spectrum data at point B from the infrared absorption spectrum data at point A in the figure is shown in FIG. The following results were obtained. The micro opening area of the aperture 20 during scanning was such that the corresponding area of the sample surface was 20×20 μm 2 . In the figure, it was found that there is a large peak P near 1700 cm-', which is the infrared absorption spectrum of the additive added to the polypropylene resin.

The amount of this additive was so small that it could not be confirmed from the infrared spectrum of the molten state, but the additive segregates during the crystallization process, and this can be confirmed by obtaining the difference spectrum. Ta.

Furthermore, we were able to find out where the particles segregated and estimate their physical properties. Therefore, this collected spectrum provides effective information for determining the preferred temperature conditions for cooling and solidifying the molten polymer and for molding, and for selecting a preferred curing agent.

It goes without saying that the present invention includes various other modifications.

For example, in Figure 3, at the part where the light intensity suddenly changes and before and after that, the infrared spectrum is measured for a specific minute area of the sample, or the infrared spectrum is measured by scanning this minute area. By doing so, changes or segregation in chemical structure at and before and after the phase change may be detected.

Further, another optical path switching mirror and a monitor television may be attached so that the sample can be monitored.

Furthermore, in the embodiment described in -, the case where the temperature of the sample is lowered has been explained, but the case where the sample is heated may also be used.

[Effects of the Invention] As explained above, in the thermal analysis/microscopic spectroscopy method according to the present invention, thermal analysis is performed by changing the temperature of a sample placed on the stage of a microscope, thereby determining macroscopic changes such as phase changes in the sample. By measuring the spectra under the microscope, we can detect changes in the chemical structure and microscopic changes in the spatial distribution of the sample in relation to the macroscopic changes, making it easy to determine polymer molding conditions and cure. It has the excellent effect of determining the material of high melting point plastics, and also understanding the relationship between glass transition, crystallization, chemical reactions, thermal stability, or phase equilibrium of polymers, and functional groups or molecular structural formulas. This will greatly contribute to the development of new polymer materials such as

Further, the thermal analysis/microscopic spectrophotometer according to the present invention is an apparatus that implements the method described in "1", and exhibits the above-mentioned effects.

[Brief explanation of the drawing]

1 to 5 relate to one embodiment of the present invention, in which FIG. 1 is a block diagram of a thermal analysis/microspectrophotometer, FIG. 2 is a flowchart showing the processing procedure of the controller 34, and FIG.
Figures 5 to 5 relate to the measurement results, Figure 3 is a line diagram showing the relationship of light intensity of a specific infrared wavelength to changes in sample temperature, Figure 4 is a diagram showing the boundaries of spherulites when viewed through a microscope, FIG. 5 is a difference spectrum diagram of the infrared absorption spectra of point B and point B shown in FIG. 10: X-Y stage 12: Hot stage 12A, Sample cell 12B: Heater 12C Temperature detector 18 Polarizer 20 Aperture 22: Optical path switching mirror 28, Guide optical system

Claims (7)

[Claims] (1) By changing the temperature of a sample placed on the stage of a microscope and performing thermal analysis, we can capture macroscopic changes in the sample, and by measuring the spectrum of a minute area of the sample under the microscope, we can detect macroscopic changes in the sample. A thermal analysis/microspectroscopy method characterized by capturing microscopic changes in the sample in relation to changes. (2) The thermal analysis is differential thermal analysis, differential scanning calorimetry, or thermal analysis by capturing changes in the intensity of a specific infrared wavelength of light emitted from the microscope. The method described in section. (3) In the process of changing the sample temperature, the sample temperature is held substantially constant, and in this state, the minute area is moved to perform spectrum measurement on a plurality of minute areas. The method described in Section 2. (4) The method according to claim 3, wherein the sample temperature is maintained substantially constant in the vicinity where a phase change is detected by thermal analysis. (5) The method according to claim 2, wherein the thermal analysis and the spectrum measurement are performed simultaneously while fixing the minute region and increasing or decreasing the temperature of the sample. (6) An optical microscope, a thermal analysis device that performs thermal analysis by changing the temperature of a sample placed on the stage of the optical microscope, and a spectrophotometer into which light emitted from the optical microscope is incident. Features of thermal analysis/microscopic spectrophotometer. (7) The apparatus according to claim 6, wherein the optical microscope is a scanning optical microscope that is equipped with an aperture that narrows down the field of view and that scans a sample placed on a stage.