Sample container and thermal analyzer

Abstract

A sample container and a thermal analyzer that enable stable observation of measurement samples regardless of the surface condition of the sample container during thermal analysis are proposed. The sample container is a sample container used with a thermal analyzer for measuring a thermal behavior according to a temperature variation resulting from heating or cooling of a measurement sample and for observing the measurement sample. The sample container comprises a body in a cylindrical shape with a bottom and an open top, and a loading plate placed on a bottom surface inside the body on which the measurement sample is to be placed. The average roughness of a surface of the loading plate facing the measurement sample is lower than the average roughness of the bottom surface.

Description

[0001] The present disclosure relates to a sample container used with a thermal analyzer that heats a sample and measures physical variations, including measuring a thermal weight and a heat quantity of the sample according to a temperature variation, and a thermal analyzer using the sample container.

[0002] In related art, a technique called thermal analysis, which heats a sample and measures physical variations of the sample according to a temperature variation, has been used as a technique for evaluating the temperature properties of a sample. Thermal analysis is defined in the "General Rules for Thermal Analysis" in JIS K 0129:2005, and techniques for measuring physical properties of a measurement target (a sample) when the temperature of the sample is controlled by a program are all referred to as thermal analysis.As a general thermal analysis, there are five types of methods, (1) differential thermal analysis (TDA), which detects temperature (temperature difference), (2) differential scanning calorimetry (DSC), which measures heat flow difference, (3) thermogravimetry (TG), which detects mass (weight variation), (4) thermomechanical analysis (TMA), which detects dynamic properties, and (5) dynamic mechanical analysis (DMA).

[0003] Furthermore, there is also a thermogravimeter differential thermal analyzer (TG / DTA or TG / DSC) that simultaneously measures thermal weight and differential heat (see, for example, Japanese Patent Laid-Open Publication No. Hei. 8-327573).

[0004] Furthermore, there is a recent demand for observing the state of samples in thermal analysis, so a thermal analyzer is known that has an opening on a furnace for heating a sample, allowing the sample to be observed through the opening. Cylindrical sample containers with a bottom and an open top, as described in Japanese Patent Laid-Open Publication No. JP2015-108540, are used for such observation.

[0005] However, if polishing marks or rough surfaces of the container material remain on the bottom surface of a sample container during container molding, the roughness of the bottom surface will affect reflected light when observing a sample, making it difficult to observe the sample. In particular, when a sample is transparent (see-through), there is a problem that the bottom surface of a sample container under the sample will affect the observation of the sample.

[0006] Accordingly, the present disclosure has been made to solve the problems described above, and an object of the present disclosure is to provide a sample container and a thermal analyzer that enable stable observation of a measurement sample regardless of the surface state of the sample container in thermal analysis.

[0007] An object of the present invention is to provide a sample container and a thermal analyzer with improved characteristics.

[0008] This object is achieved by a sample container according to claim 1 and a thermal analyzer according to claim 6.

[0009] To achieve this objective, a sample container for a thermal analyzer is a sample container used with a thermal analyzer for measuring thermal behavior according to a temperature variation resulting from heating or cooling of a measurement sample and for observing the measurement sample. The sample container comprises a body in a cylindrical shape with a bottom and an open top, and a loading plate placed on a bottom surface within the body on which the measurement sample is to be placed. The average roughness (Ra1) of a surface of the loading plate facing the measurement sample is lower than the average roughness (Ra2) of the bottom surface.

[0010] According to the sample container for a thermal analyzer, when the loading plate with a roughness lower than that of the soil surface is placed on the soil surface of the body, it is possible to stably observe the measurement sample regardless of the surface condition of the soil surface of the body without being influenced by the roughness of the soil surface.

[0011] In the sample container for a thermal analyzer of the present disclosure, the measurement sample may be transparent or translucent.

[0012] When the measurement sample is transparent or translucent, the bottom surface of the sample container under the measurement sample does not affect the observation of the sample, so it is possible to observe the measurement sample more stably.

[0013] In the sample container for a thermal analyzer of the present disclosure, Ra1 can be equal to or less than 0.2 μm. According to the sample container for a thermal analyzer of the present disclosure, it is possible to reliably make the surface of the loading plate smooth, so that the influence of the roughness of the loading plate is suppressed, and accordingly, it is possible to observe measurement samples more stably.

[0014] In the sample container for a thermal analyzer of the present disclosure, the thermal conductivity of the loading plate at 25°C is equal to the thermal conductivity of the body at 25°C with an error tolerance of ± 10%.

[0015] According to the sample container for a thermal analyzer, the degrees of thermal conductivity of the loading plate and the body become the same when heated and cooled for measurement by the thermal analyzer, so that it is possible to observe measurement samples more stably.

[0016] In the sample container for a thermal analyzer of the present disclosure, the loading plate and the body may be made of an identical material.

[0017] According to the sample container for a thermal analyzer, if the loading plate and the body are made of the identical material, the thermal conductivity of the same will be the same.

[0018] A thermal analyzer comprises the sample container for a thermal analyzer, a furnace surrounding the sample container and having an observation port, and an imaging unit enabling observation of the measurement sample through the observation port, wherein the thermal analyzer measures the thermal behavior of the measurement sample according to a temperature variation in the furnace.

[0019] The thermal analyzer of the present disclosure may be a differential thermal analyzer, a differential scanning calorimeter, or a thermogravimetric device.

[0020] The thermal analyzer may further comprise an image processing unit configured to generate predetermined color information from image data of the measurement sample obtained by the imaging unit, and may superimpose the color information and the thermal behavior with respect to temperature.

[0021] According to the present disclosure, it is possible to achieve a sample container and a thermal analyzer that enable stable observation of measurement samples regardless of the surface state of the sample container in thermal analysis.

[0022] Preferred embodiments of the present invention are explained in more detail below with reference to the accompanying drawings. Fig. 1 is a cross-sectional view showing the configuration of a thermal analyzer according to an embodiment of the present disclosure; Fig. 2 is a perspective view showing the configuration of a sample container according to an embodiment of the present disclosure; Fig. 3 an axial cross-sectional view of the sample container; Fig. 4 is a view showing a bending portion of the sample container; and Fig. 5 is a flowchart illustrating the operation of a thermal analyzer using a sample container of the present disclosure.

[0023] Hereinafter, embodiments of the present disclosure will be described with reference to drawings. Fig. 1 is a cross-sectional view showing the configuration of a thermal analyzer according to an embodiment of the present disclosure.

[0024] A thermal analyzer 1 is a differential scanning calorimeter (DSC) and has the same configuration as prior art differential scanning calorimeters, except that a window 11W through which it is possible to observe the inside of a lid 11 of a furnace 10 is provided, so that the outline will be described.

[0025] The thermal analyzer 1 includes: a measurement sample container 2 that accommodates a measurement sample S; a reference substance container 3 that accommodates a reference substance R; a furnace 10; thermistors 4 that are interposed between the measurement sample container 2, the reference substance container 3, and the furnace 10 and form heat flow paths therebetween; a measurement sample-side thermocouple 7; a reference substance-side thermocouple 8; a light source 31 that is an illumination unit for emitting visible light onto at least the measurement sample S, such as an LED; a CCD camera 32 that is an imaging unit for photographing at least the measurement sample S; and a personal computer 50.

[0026] A heater 12, for example coiled wires, is wound around the outside of the furnace 10 and heats the furnace 10. The outside of the heater 12 is covered with a cover (not shown).

[0027] The CCD camera 32 is, for example, an area scan camera, but may also be a line scan camera, and other solid-state image sensing devices such as a CMOS camera may be used.

[0028] The personal computer 50 includes a central processing unit (CPU) 51, a storage unit 52, e.g., a hard disk, a display 53, e.g., a liquid crystal monitor, a keyboard or a mouse (not shown), etc.

[0029] The furnace 10 has a cylindrical shape and an H-shaped axial cross-section. A substantially double-disk-like thermal plate 5 is placed on an annular projection projecting inwardly from the axial center in the diametric direction.

[0030] The measurement sample container 2 and the reference substance container 3 are placed on top of the thermal plate 5 with two thermistors 4 in between, and the measurement sample container 2 and the reference substance container 3 are accommodated in an inner space surrounded by the furnace 10.

[0031] A measurement sample S is accommodated in the measurement sample container 2, a pressure plate 22 is placed on top of the measurement sample S, and a loading plate 23 is arranged between the bottom surface of the measurement sample container 2 and the measurement sample S ( Fig. 2). The printing plate 22 is made of a material that is transparent or translucent and transmits visible light with a predetermined light transmittance. Silica glass, sapphire glass, yttrium aluminum garnet (YAG) ceramic, Tempax, Neoceram (registered trademark), Vycor (registered trademark), and Pyrex (registered trademark) can be suitably used as the transparent material.

[0032] Meanwhile, a pressure plate, the same as that of the measurement sample container, may also be placed on the reference substance R in the reference substance container 3 holding the reference substance R, so that the measurement sample S and the reference substance R are safely heated under the same condition in the furnace 10. The pressure plate 22 is not a necessary component in the present disclosure. When the pressure plate 22 is used, it only needs to be used for at least the measurement sample container 2.

[0033] However, it is preferable to place the same pressure plate as that of the measurement sample container on the reference substance R in the reference substance container 3.

[0034] The sample-side thermocouple 7 and the reference-substance-side thermocouple 8 pass through the thermistors 4 and the thermoplate 5, and their first ends are connected to the bottoms of the sample container 2 and the reference-substance container 3, respectively, by soldering. Meanwhile, second ends of the sample-side thermocouple 7 and the reference-substance-side thermocouple 8 are extended downward from the furnace 10 and connected to an amplifier 14, which forms a signal processing circuit.

[0035] Accordingly, the sample-side thermocouple 7 and the reference substance-side thermocouple 8 form so-called differential thermocouples and enable the detection of a temperature difference between the sample S and the reference substance R. This temperature difference is recorded as a heat flow difference signal. Meanwhile, the temperature of a sample is recorded by the sample-side thermocouple 7.

[0036] The temperature of the furnace 10 is input to the CPU 51 through various control circuits, and the CPU 51 controls the application of electricity to the heater 12, thereby controlling the furnace 10 to heat or cool at a predetermined rate.

[0037] The lid 11 is removably placed over the opening at the top of the oven 10, thereby isolating the interior of the oven 10 from the outside air.

[0038] A window 11W made of silica glass is arranged at the portion of the lid 11 that overlaps the measurement sample container 2 in the axial direction of the furnace 10, and the CCD camera 32 is arranged above the window 11W.

[0039] A light source 31 for illuminating the measurement sample S in the furnace 10 through the window 11W is arranged above the window 11W on a line different from the axial line of the CCD camera 32.

[0040] Incident light (visible light) 31L is emitted from the light source 31 onto the measurement sample S, and the CCD camera 32 receives a luminance or intensity of reflected light 32L from the measurement sample S.

[0041] Filters 31F and 32F are arranged between the window 11W and the light source 31 and between the window 11W and the CCD camera 32, respectively, so that only light with a specific component is emitted onto the window 11W and only reflected light with a specific component is sent to the CCD camera 32. However, the filters 31F and 32F are not necessary. In coaxial endoscopic illumination (half-mirror type), the optical axis of the light source 31 for emitted light and the optical axis of the camera 32 are aligned.

[0042] Next, the sample container according to an embodiment of the present disclosure will be described by illustrating the measurement sample container 2. Fig. 2 is a perspective view showing the configuration of the measurement sample container 2, and Fig. 3 is a cross-sectional view of the sample container 2, cut in the axial direction L.

[0043] The measuring sample container 2 comprises a body 21 in a cylindrical shape with a bottom and an open top, a pressure plate 22, a loading plate 23 and a lid 24, wherein the pressure plate 22, the loading plate 23 and the lid 24 are formed substantially in disc shapes having a diameter equal to or slightly smaller than the inner diameter of the body 21.

[0044] The pressure plate 22 is transparent or translucent as described above and presses a measurement sample S placed on the bottom surface of the body 21 from above.

[0045] The body 21, the charging plate 23 and the cover 24 are made of aluminum (alloy), for example.

[0046] The pressure plate 22 and the cover 24 are not essential components in the present disclosure.

[0047] The loading plate 23 is placed on the bottom surface 21b inside the body 21 and is provided for placing a measurement sample S thereon.

[0048] The average roughness Ra1 of the surface (top) 321 of the loading plate 23 facing the measurement sample S is lower than the average roughness Ra2 of the bottom surface 21b.

[0049] The average roughness Ra1 and Ra2 can be the arithmetic mean roughness defined in JIS-B0601:2013.

[0050] When forming the body 21, if polishing marks or rough surfaces of the material of the body 21 remain on the bottom surface 21b inside the body 21, the roughness of the bottom surface 21b affects reflected light when observing a sample, especially when the measurement sample is transparent (see-through), so that it may be difficult to observe the sample.

[0051] Accordingly, when the loading plate 23 having a lower roughness than the ground surface 21b is placed on the ground surface 21b, as shown in Fig. 3, incident light 31L that has passed through a measurement sample S reflects from the surface of the loading plate 23 and becomes reflected light 32L, so that it is possible to stably observe the measurement sample regardless of the surface condition of the bottom surface 21b of the body 21 without being influenced by the roughness of the bottom surface 21b.

[0052] When Ra1 is less than 0.2 μm, it is possible to surely make the surface of the loading plate 23 smooth, so that the influence by the roughness of the loading plate 23 is suppressed, and accordingly, it is possible to observe measurement samples more stably.

[0053] When the thermal expansion coefficient of the loading plate 23 at 25°C is equal to the thermal expansion coefficient of the body 21 at 25°C with an error tolerance of ± 10%, the degrees of thermal expansion of the loading plate 23 and the body 21 become the same when heated and cooled for measurement by the thermal analyzer, so that it is possible to observe measurement samples more stably.

[0054] In particular, when the loading plate 23 and the body 21 are made of an identical material, the thermal expansion coefficients thereof become the same, which is preferable.

[0055] In this embodiment, the pressure plate 22 is placed on top of a measurement sample S and presses the measurement sample S from above. Accordingly, since the pressure plate 22 presses the measurement sample S, the deformation of the measurement sample S resulting from heating or cooling for measurement by the thermal analyzer is suppressed, and it is possible to observe the measurement sample more stably.

[0056] In this embodiment, the cover 24 is placed on top of the pressure plate 22. The cover 24 has a hole 24h formed in the center for observing measurement samples. The (outer) peripheral edge 24e of the cover 24 protrudes vertically upward, forming a flange.

[0057] As in Fig. 4, at least portions of an opening edge 21e of the body 21 and the outer peripheral edge (flange) 24e of the lid 24 are both bent downward (over the entire circumference in this embodiment), with a measurement sample S being disposed between the bottom surface of the body 21 and the pressure plate 22, thereby forming a bent portion 26.

[0058] Since the bending portion 26 is formed, the lid 24 is pressed downward (toward the pressure plate 22). Accordingly, the pressure plate 22 presses a measurement sample S through the lid 24, whereby the measurement sample S is sufficiently pressed and the deformation of the measurement sample S or the pressure plate 22 can be further suppressed.

[0059] The opening edge 21e of the body 21 (the side in this embodiment) and the peripheral edge (flange) 24e of the cover 24 must be substantially parallel, and the cover 24 must have a flange so that bending is possible.

[0060] As long as the opening end 21e and the peripheral edge (flange) 24e are bent sections, they can be seams used for making cans, etc.

[0061] The entire opening end 21e and the peripheral edge (flange) 24e may be bent, but only one portion (e.g., four portions at regular intervals in the circumferential direction) of the peripheral edge may be bent as long as the measurement sample S is sufficiently pressed.

[0062] Next, the operation of a sample container and a thermal analyzer using the sample container will be described with reference to the flowchart of Fig. 5 described.

[0063] First, visible light is emitted from the light source 31 onto a measurement sample S, and initial image data of the measurement sample S is obtained at the CPU 51 of the personal computer 50 using the CCD camera 32 (step S10).

[0064] Next, the image data is displayed on the display 53 of the personal computer 50, and a user sets the location information of an analysis region in the image of the measurement sample S on the display 53 using a mouse, a keyboard (not shown), or the like (step S12).

[0065] The location information may be a point or an area having an area following an outer boundary. When a point is specified, a circle, etc., with a predetermined radius or a predetermined area around the point may be considered a virtual area.

[0066] Heat flow difference (DSC) signals are obtained over time while the measurement sample S is heated or cooled by the heater 12 or a cooling part (not shown) (step S14).

[0067] The processing of step S14 is the same as the processing performed by a prior art differential scanning calorimeter (DSC), the measurement sample S itself is heated or cooled, and corresponding differential scanning calories (DSC) are measured.

[0068] In the present disclosure, DSC signals are obtained with respect to any variable of time or temperature. In conventional differential scanning calorimeters, the heating or cooling rate is constant, and time and temperature are related.

[0069] The CCD camera 32 obtains image data of the image of the measurement sample S over time and outputs the image data to the CPU 51 (step S16).

[0070] When image data is obtained in step S16, the same variable as the variable (time in this embodiment) used to obtain heat flow difference signals (DSC signals) in step S14 may be used, but other variables may be used.

[0071] Next, image data corresponding to the location information of the measurement sample S set in step S12 is obtained from the image data over time in step S16 by the CPU 51 (step S18).

[0072] The image data is stored in the storage unit 52.

[0073] If the measurement sample S is an area having a region, the average value of the luminance or intensity of the pixels of the image data in the region is used.

[0074] The image data of the measurement sample S obtained in step S18 and the heat flow difference signals (DSC signals) of the measurement sample S obtained in step S14 are superimposed on each other on the display 53 (step S20).

[0075] Next, the user determines whether it is necessary to end the measurement and ends the measurement if it is necessary (YES), and returns to step S14 if it is not necessary (NO) (step S22).

[0076] When determining whether it is necessary to end the measurement in step S22, for example, it may be possible to determine that it is necessary to end the measurement by setting in advance the maximum temperature or the minimum temperature for heating or cooling the measurement sample as the end temperature, but the present disclosure is not specifically limited thereto.

[0077] Visible light is emitted from a light source in the embodiment described above, but electromagnetic waves other than X-rays, infrared light, and ultraviolet light may be emitted as visible light, and the reflected light may be detected by a detector such as an X-ray detector other than a CCD camera.

[0078] It may be possible to use color variations to obtain an image of a measurement sample S. Regarding color, information that quantifies colors may be used in addition to the luminance of specific wavelengths. As numerical information, there are Lab(L*a*b*) values of the CIE (International Commission on Illumination) 1976 color space, RGB values that express colors using combinations of red, green, and blue, referred to as the "three primary colors of light," CMYK values that express colors using combinations of cyan, magenta, and yellow, referred to as the "three primary colors," and black, etc., but the present disclosure is not limited to these. For example, XYZ values of the CIE 1931 color space, L*u*v values of the CIE 1976 color space, CIECAM02 color space, etc., may be used.

[0079] The present disclosure is not limited to the embodiments described above, and even covers various modifications and equivalents included in the spirit and scope of the present disclosure.

[0080] For example, the shapes of the sample container, body, and loading plate are not limited to the examples described above. For example, the sample container is not limited to a cylinder and can be a polygonal cylinder or an elliptical cylinder.

[0081] The thermal analyzer of the present disclosure, which measures the physical properties of samples when the temperature of the measurement targets (samples) is controlled by programs, can be applied to a thermal analyzer having the function of differential scanning calorimetry (DSC) that detects a heat flow difference, except for the above-mentioned thermogravimeter differential thermal analyzer (TG / DTA) defined in "General Rules for Thermal Analysis" in JIS K 0129:2005, and can also be applied to a differential thermal analyzer (TDA) and a thermogravimeter (TG). Explanation of reference symbols 1 thermal analyzer 2, 2B, 2C (measuring) sample container 10 oven 11W Opening for observation (window) 21, 21B, 21C Body 21e opening edge 22 Pressed part 24, 24B, 24C lid 24h, 24h2, 24h3 hole 24e outer peripheral edge 26 Bending section 31 Light source 32 imaging devices (CCD camera) 51 CPU (control) 53 Advertisement S (measurement) sample QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 8-327573

[0003] JP 2015-108540

[0004]

Claims

[1] Sample container (2, 2B, 2C) used with a thermal analyzer (1) for measuring a thermal behavior according to a temperature variation resulting from the heating or cooling of a measurement sample (S) and for observing the measurement sample (S), the sample container (2, 2B, 2C) having the following features: a body (21, 21B, 21C) in a cylindrical shape with a bottom and an open top; and a loading plate (23) placed on a floor surface (21b) within the body (21, 21B, 21C) on which the measurement sample (S) is to be placed, wherein the average roughness (Ra1) of a surface of the loading plate (23) facing the measuring sample (S) is lower than the average roughness (Ra2) of the bottom surface (21b). [2] Sample container (2, 2B, 2C) according to claim 1, wherein the measurement sample (S) is transparent or translucent. [3] The sample container (2, 2B, 2C) according to claim 1 or 2, wherein Ra1 is the arithmetic mean roughness defined in JIS-B0601:2013 and is equal to or less than 0.2 µm. [4] Sample container (2, 2B, 2C) according to claim 1 or 2, wherein the thermal conductivity of the loading plate (23) at 25°C is equal to the thermal conductivity of the body (21, 21B, 21C) at 25°C with an error tolerance of ± 10%. [5] Sample container (2, 2B, 2C) according to claim 3, wherein the loading plate (23) and the body (21, 21B, 21C) are made of an identical material. [6] A thermal analyzer (1) comprising the sample container (2, 2B, 2C) for a thermal analyzer (1) according to any one of claims 1 to 5, a furnace (10) surrounding the sample container (2, 2B, 2C) and having an observation port (11W), and an imaging unit enabling observation of the measurement sample (S) through the observation port (11W), wherein the thermal analyzer (1) measures a thermal behavior of the measurement sample (S) according to a temperature variation in the furnace (10). [7] Thermal analyzer (1) according to claim 6, wherein the thermal analyzer (1) is a differential thermal analyzer (1), a differential scanning calorimeter or a thermogravimetric device. [8] The thermal analyzer (1) according to claim 6 or 7, further comprising an image processing unit configured to generate predetermined color information from image data of the measurement sample (S) obtained by the imaging unit, wherein the color information and the thermal behavior with respect to temperature are displayed superimposed.

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