Temperature history estimation device, temperature history estimation method, and temperature history estimation program

Abstract

To estimate a temperature history of a rubber composition by a simple method.SOLUTION: A temperature history estimation device (1) estimates a temperature history of a measuring object as a rubber composition. The temperature history estimation device (1) includes: a measurement value reception unit (101) that receives a measurement value of a carbonization ratio for a polymer contained in the measuring object; a storage unit (20) that stores data (202) indicating a relation between the carbonization ratio and a temperature of the polymer contained in the measuring object; and a temperature history estimation unit (102) that estimates the temperature history of the measuring object on the basis of the measurement value of the carbonization ratio and the data (202).SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a temperature history estimation device, a temperature history estimation method, and a temperature history estimation program. [Background technology]

[0002] Conventionally, the degree of deterioration of a rubber composition has been estimated by measuring changes in structure using FT-IR or changes in rubber hardness (see, for example, Non-Patent Document 1). [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Tetsuya Kawashima and Toshio Ogawa, "Destruction of NBR due to Thermal Degradation," Journal of the Society of Rubber Industry of Japan, Vol. 75, No. 6, 2002, The Society of Rubber Industry of Japan, p. 257-262 Summary of the Invention [Problem to be solved by the invention]

[0004] However, these changes are difficult to quantify and have large errors, making it difficult to accurately estimate the temperature history of a rubber composition sample.

[0005] The present invention has been made in consideration of the above-mentioned problems, and an object of the present invention is to provide a technique for estimating the temperature history of a rubber composition by a simple method. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the temperature history estimation device of the present invention is a device that estimates the temperature history of a measurement object which is a rubber composition, and is equipped with a measurement value receiving unit that receives a measurement value of the carbonization rate of the polymer contained in the measurement object, a memory unit that stores data indicating the relationship between the carbonization rate of the polymer contained in the rubber composition sample and temperature, and a temperature history estimation unit that estimates the temperature history of the measurement object based on the measurement value of the carbonization rate and the data.

[0007] In a temperature history estimation device according to one aspect of the present invention, the temperature history estimation unit corresponds the measured value of the carbonization rate to the carbonization rate of the polymer contained in the sample in the data to estimate the temperature history of the object to be measured.

[0008] In the temperature history estimation device according to one embodiment of the present invention, the measured value of the carbonization rate is measured using a thermogravimetric-differential thermal analyzer.

[0009] In order to achieve the above-mentioned object, the temperature history estimation method of the present invention is a method for estimating the temperature history of a measurement object which is a rubber composition, and includes the steps of receiving a measured value of the carbonization rate of a polymer contained in the measurement object, and estimating the temperature history of the measurement object based on the measured value of the carbonization rate and data showing the relationship between the carbonization rate of the polymer contained in the rubber composition sample and temperature.

[0010] In order to achieve the above-mentioned object, the temperature history estimation program of the present invention is a program executed by a computer to estimate the temperature history of a measurement object which is a rubber composition, and causes the computer to execute the steps of accepting a measured value of the carbonization rate of a polymer contained in the measurement object, and estimating the temperature history of the measurement object based on the measured value of the carbonization rate and data showing the relationship between the carbonization rate of the polymer contained in the rubber composition sample and temperature.

[0011] In a temperature history estimation method and a temperature history estimation program according to one embodiment of the present invention, in the step of estimating the temperature history of the object to be measured, the measured value of the carbonization rate is associated with the carbonization rate of the polymer contained in the sample in the data to estimate the temperature history of the object to be measured.

[0012] In the temperature history estimation method and temperature history estimation program according to one aspect of the present invention, the measured value of the carbonization rate is measured using a thermogravimetric-differential thermal analyzer. Effect of the Invention

[0013] According to the temperature history estimation device, the temperature history estimation method, and the temperature history estimation program of the present invention, the temperature history of a rubber composition can be estimated by a simple method. [Brief description of the drawings]

[0014] [Figure 1] 1 is a functional block diagram of a temperature history estimation device according to an embodiment of the present invention. [Diagram 2] 1 is a cross-sectional perspective view of a gear damper having an example of a rubber composition whose temperature history is estimated by a temperature history estimation device according to an embodiment of the present invention. FIG. [Diagram 3] 10 is a schematic diagram showing an example of a screen for accepting input of a measured value of a carbonization rate, which is displayed on a notification unit by a measured value accepting unit in the temperature history estimation device according to the present embodiment. FIG. [Figure 4] 4 is a graph showing a TG-DTA curve of a rubber composition whose temperature history is estimated by the temperature history estimation device according to the present embodiment. [Diagram 5] 1 is a schematic diagram for explaining the principle of deterioration of a rubber composition. FIG. [Figure 6] 4 is a graph showing the relationship between the carbonization rate of a polymer and the temperature history in a rubber composition whose temperature history is estimated by the temperature history estimation device according to the present embodiment. [Figure 7] 2 is a graph showing the relationship between rubber hardness change and temperature history in a rubber composition. [Figure 8]1 is a graph showing the relationship between FT-IR and temperature history in a rubber composition. [Figure 9] 10 is a schematic diagram showing an example of a screen displaying an estimation result of a temperature history calculated based on measured values, which is displayed on a notification unit by a temperature history estimation unit in the temperature history estimation device according to the present embodiment. FIG. [Figure 10] 4 is a flowchart for explaining a temperature history estimation method executed by the temperature history estimation device according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0016] FIG. 1 is a functional block diagram of a temperature history estimation device 1 according to an embodiment of the present invention.

[0017] As shown in FIG. 1, a temperature history estimation device 1 according to an embodiment of the present invention is an information processing device including a data processing control unit 10 and a storage unit 20, such as a PC (Personal Computer), a smartphone, or a tablet terminal.

[0018] The data processing control unit 10 is configured with an information processing device capable of executing a computer program, such as a processor such as a CPU (Central Processing Unit) and an MCU (Micro Controller Unit) including a storage device. The storage device included in the data processing control unit 10 is realized by a known storage device (storage medium), such as a ROM, a RAM, or a flash memory.

[0019] The data processing control unit 10 is a functional unit that comprehensively controls each functional unit in the temperature history estimation device 1. As described above, the data processing control unit 10 includes a processor such as a CPU. The data processing control unit 10 controls each functional unit in the temperature history estimation device 1 by executing various calculations according to a program stored in the storage unit 20, for example.

[0020] The storage unit 20 is a non-volatile storage device that stores various information described later, and is, for example, a magnetic storage device such as a hard disk drive, or an electrical storage device such as a solid state drive.

[0021] The storage unit 20 stores various programs for enabling the information processing device to function as the temperature history estimation device 1. The various programs stored in the storage unit 20 include a temperature history estimation program 201 according to the present invention. The storage unit 20 also stores data (hereinafter referred to as "carbonization rate-temperature sample data 202") indicating the relationship between the carbonization rate of a polymer contained in a sample of a rubber composition having a composition corresponding to the measurement object and temperature, which is used in a calculation for estimating the temperature history of the measurement object. Furthermore, the storage unit 20 is a functional unit for storing various data such as a temperature history estimation result 203.

[0022] The operation unit 30 is an input interface for the user to operate the temperature history estimation device 1. Examples of the operation unit 30 include various buttons, a keyboard, a pointing device, a touch panel, and the like. For example, the user can operate the operation unit 30 to set various conditions for estimating the temperature history of the measurement object in the temperature history estimation device 1, and can instruct the temperature history estimation device 1 to execute and stop the temperature history estimation process. The operation unit 30 is not limited to the above-mentioned buttons and touch panel, and may have a function that allows the user to accept input for operating the temperature history estimation device 1. The operation unit 30 may accept operations by, for example, voice command input.

[0023] The notification unit 40 is a functional unit for outputting various information such as identification of the measurement object in the temperature history estimation device 1, confirmation of the name of the carbonization rate-temperature sample data 202 used in the temperature history estimation process, confirmation of stored data, estimation conditions, and estimation results to notify the user of the information. The notification unit 40 is, for example, a display device equipped with an LCD (Liquid Crystal Display) or an organic EL. The notification unit 40 may also be a device that outputs audio data such as a speaker or headphones to notify the user of the information. The notification unit 40 may also be a display device equipped with a touch panel that realizes some of the functions of the operation unit 30.

[0024] The interface unit 50 is configured with various interfaces that enable data input / output between the temperature history estimation device 1 and an external device (not shown). The interface unit 50 may be various communication interfaces such as LAN, USB, RS-232C, etc. The interface unit 50 enables the temperature history estimation device 1 to input / output data via the external device. The interface unit 50 may include a communication circuit or the like that outputs various data used for estimating the temperature history to the outside by wire or wirelessly. By using these various communication interfaces, the temperature history estimation device 1 can communicate with a wide area network (WAN) represented by the Internet or a local area network (LAN).

[0025] The temperature history estimation device 1 has the above hardware configuration, and the data processing control unit 10 executes a temperature history estimation program stored in the storage unit 20, whereby the hardware and software work together to estimate the temperature history of the measurement object, which is a rubber composition. The temperature history estimation device 1 has a measurement value receiving unit 101, the storage unit 20, and a temperature history estimation unit 102 as functional blocks realized by the temperature history estimation program.

[0026] 2 is a cross-sectional perspective view of a gear damper 2 having an example of a rubber composition whose temperature history is estimated by the temperature history estimation device 1 according to this embodiment. In this embodiment, the temperature history estimation device 1 estimates the value of the temperature of heat received by a rubber composition, such as a rubber ring 3 provided in the gear damper 2, by measuring the carbonization rate of a polymer contained in the rubber composition, for example, hydrogenated nitrile rubber (HNBR), thereby estimating the temperature of the heat received by the rubber composition, i.e., the temperature history.

[0027] The rubber composition used as the measurement object for performing the temperature history estimation process by the temperature history estimation device 1 is not limited to those used in vibration-proof rubber products such as the gear damper and torsional damper shown in Figure 2, but can be used for various rubber products.

[0028] The measurement value receiving unit 101 receives a measurement value of the carbonization rate of the polymer contained in the measurement object (hereinafter referred to as the "measurement value"). The measurement value is measured using a thermogravimetry-differential thermal analysis (TG-DTA) which is an apparatus that simultaneously performs thermogravimetry and differential thermal analysis. Specifically, the amount of carbonization caused by structural change of the rubber due to temperature history is measured from the weight loss amount in the rubber combustion range (in air, about 450 to 550°C).

[0029] FIG. 3 is a schematic diagram showing an example of a measurement value reception screen 300 for receiving input of a measurement value of a carbonization rate, which is displayed on the notification unit 40 by the measurement value reception unit 101 in the temperature history estimation device 1 according to the present embodiment. The measurement value reception screen 300 is displayed, for example, on a display device constituting the notification unit 40 (see FIG. 1). For example, a user can input a measurement value to a measurement value input unit 301 in the measurement value reception screen 300 via the operation unit 30 or the interface unit 50. The measurement value input to the measurement value input unit 301 is received by the measurement value reception unit 101. Note that the method of inputting the measurement value is not limited to the above-mentioned example.

[0030] The temperature history estimation unit 102 estimates the temperature history of the measurement object based on the measurement value received by the measurement value receiving unit 101 and the carbonization rate-temperature sample data 202 stored in the memory unit 20. Specifically, the temperature history estimation unit 102 associates the measurement value of the carbonization rate received by the measurement value receiving unit 101 with the carbonization rate of the polymer contained in the sample in the carbonization rate-temperature sample data 202 to estimate the temperature history of the measurement object.

[0031] Fig. 4 is a graph showing a TG-DTA curve of a rubber composition for which a temperature history is estimated by the temperature history estimation device 1 according to the present embodiment. In Fig. 4, the left vertical axis indicates the weight reduction rate (wt%), the right vertical axis indicates the temperature (°C), and the horizontal axis indicates the time (min). Fig. 4 shows a TG-DTA curve 210 of a new rubber composition (not placed in a high-temperature environment) and a TG-DTA curve 211 of a rubber composition that has been subjected to heat at a predetermined temperature (e.g., 150°C). In the present embodiment, the rubber composition used in a high-temperature environment is the target for which a temperature history is estimated, that is, the rubber composition that is the measurement target.

[0032] FIG. 5 is a schematic diagram for explaining the principle of deterioration of a rubber composition. As can be seen from the TG-DTA curve 210 of a new rubber composition shown in FIG. 4 and the TG-DTA curve 211 of a rubber composition that has been subjected to heat at a predetermined temperature, the weight percentage of char (carbon precursor) increases in the rubber composition when it is used in a high-temperature environment. As shown in FIG. 5, it is estimated that the polymer of the rubber composition, such as HNBR, is cyclized in a high-temperature environment and transformed into a char (carbon precursor). For this reason, the temperature history estimation device 1 estimates the temperature history of the measurement object based on the carbonization rate of the polymer contained in the measurement object of the rubber composition.

[0033] FIG. 6 is a graph showing the relationship between the carbonization rate of the polymer and the temperature history in the rubber composition whose temperature history is estimated by the temperature history estimation device 1 according to the present embodiment. In FIG. 6, the vertical axis shows the carbonization rate [%] of the polymer, and the horizontal axis shows the temperature history [°C] of the rubber composition. As shown in FIG. 6, in the rubber composition whose temperature history is estimated by the temperature history estimation device 1, as the carbonization rate of the polymer increases, the temperature shown by the temperature history received by the rubber composition containing the polymer also increases. In other words, if the carbonization rate of the polymer can be measured in the rubber composition, it is possible to estimate the temperature history received by the rubber composition. In this graph showing the relationship between the carbonization rate of the polymer and the temperature history, the line L1 indicates a predetermined temperature and carbonization rate that are the basis for judging the deterioration of the rubber composition. It can be seen that the point P4 that is above the line L1 among any number of points plotted in the graph, for example, points P1 to P4 in FIG. 5, is a temperature history that exceeds the above-mentioned predetermined temperature.

[0034] Fig. 7 is a graph showing the relationship between the change in rubber hardness and the temperature history in a rubber composition, and Fig. 8 is a graph showing the relationship between the FT-IR and the temperature history in a rubber composition.

[0035] In the evaluation using the rubber hardness change shown in FIG. 7 and the evaluation using FT-IR (Fourier Transform-Infrared Spectroscopy) shown in FIG. 8, there is a large variation between the values ​​measured from the rubber composition and the temperature history of the rubber composition. For this reason, it is difficult to estimate the temperature history of the rubber composition using the rubber hardness change and FT-IR. In addition, when estimating the temperature history from the structural change by FT-IR, the structural change at high temperatures cannot be captured from the measured value, making normalization difficult.

[0036] Therefore, the temperature history estimation device 1 stores in the storage unit 20 a combination of a temperature history value and a carbonization rate of a polymer in the temperature history, which is measured in advance from a sample of a rubber composition having the same composition as the measurement target, as carbonization rate-temperature sample data 202. The carbonization rate-temperature sample data 202 is stored in the storage unit 20, for example, for each type of rubber composition. In the carbonization rate-temperature sample data 202, the temperature history associated with the carbonization rate may be stored in the storage unit 20 at intervals (steps) of any value, such as every 20°C for the temperature history or every 5% for the carbonization rate.

[0037] Then, the temperature history estimation device 1 identifies a temperature history value corresponding to the measured value of the carbonization rate received from the measurement value receiving unit 101 from the carbonization rate-temperature sample data 202 stored in the storage unit 20. In this manner, the temperature history estimation device 1 can estimate the temperature history of a rubber composition by measuring the carbonization rate of the polymer of the rubber composition.

[0038] 9 is a schematic diagram showing an example of a temperature history estimation result display screen 310 that displays the estimation result of the temperature history calculated based on the measured value, which is displayed on the notification unit 40 by the temperature history estimation unit 102 in the temperature history estimation device 1 according to the present embodiment. The temperature history estimation result display screen 310 is displayed, for example, on a display device constituting the notification unit 40. The user can recognize the estimation result of the temperature history by, for example, checking the numerical value displayed on the estimation result display unit 311 in the temperature history estimation result display screen 310. Note that the display method and output method of the estimation result of the temperature history are not limited to the above-mentioned example.

[0039] FIG. 10 is a flowchart for explaining the temperature history estimation method executed by the temperature history estimation device 1 according to the present embodiment.

[0040] First, in the temperature history estimation device 1, the measurement value receiving unit 101 receives an input of a measurement value of the carbonization rate of the polymer of the measurement object from the operation unit 30 or the interface unit 50 (step S101).

[0041] The temperature history estimation unit 102 searches the memory unit 20 for carbonization rate-temperature sample data 202 that corresponds to the measurement value of the object to be measured received by the measurement value receiving unit 101, i.e., for a rubber composition having an equivalent composition (step S102).

[0042] The temperature history estimation unit 102 judges whether or not the carbonization rate-temperature sample data 202 corresponding to the measurement value of the measurement object is in the storage unit 20 (step S103). If the corresponding carbonization rate-temperature sample data 202 is not in the storage unit 20 (S103: NO), the temperature history estimation unit 102 notifies the user via the notification unit 40 that the corresponding carbonization rate-temperature sample data 202 is to be stored (step S104). After S104, the temperature history estimation unit 102 returns to the process of S102.

[0043] If there is corresponding carbonization rate-temperature sample data 202 in the memory unit 20 (S103: YES), the temperature history estimation unit 102 estimates the temperature history of the measurement object based on the measurement value of the measurement object and the carbonization rate-temperature sample data 202 (step S105).

[0044] The temperature history estimation unit 102 determines whether or not the estimation process of the temperature history of the measurement object has been completed (step S106) by associating the measurement value of the measurement object with the carbonization rate value in the carbonization rate-temperature sample data 202. If the estimation process of the temperature history of the measurement object has not been completed (S106: NO), the temperature history estimation unit 102 notifies the notification unit 40 of an error message indicating that the temperature history estimation process has not been completed (step S107), and returns to the process of S101.

[0045] If the estimation process of the temperature history of the measurement object is completed (S106: YES), the temperature history estimation unit 102 outputs the estimated value of the temperature history of the measurement object from the notification unit 40 (step S108). After the process of S108, the temperature history estimation device 1 ends the process.

[0046] As described above, by executing a temperature history estimation program in the temperature history estimation device 1 according to this embodiment, a temperature history estimation method can be executed in which the temperature history of a rubber composition is estimated based on the measured value of the carbonization rate of the polymer contained in the rubber composition of the measurement object.

[0047] Specifically, in the temperature history estimation method executed by the temperature history estimation device 1 according to the present embodiment, attention is paid to the fact that when rubber (NBR) deteriorates and the structure of the rubber changes, the change occurs via a carbon precursor. In the temperature history estimation method, the amount of carbon precursor, i.e., the carbonization rate of the polymer, is measured using TG-DTA, and the temperature history of the measurement object is estimated based on the relationship between the carbonization rate and the temperature history. Here, the temperature history of the rubber composition can be used as an index of the deterioration degree. Compared with FT-IR and rubber hardness change, TG-DTA has a smaller error in the relationship between each value and the temperature history. Also, compared with FT-IR and rubber hardness change, TG-DTA can be easily quantified.

[0048] Therefore, according to the temperature history estimation method executed by the temperature history estimation device 1, it is possible to estimate the temperature history of the rubber composition in a simple manner.

[0049] Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment of the present invention, and includes all aspects included in the concept of the present invention and the scope of the claims. In addition, each configuration may be appropriately and selectively combined so as to achieve at least a part of the above-mentioned effects. For example, the shape, material, arrangement, size, etc. of each component in the above embodiment may be appropriately changed depending on the specific use mode of the present invention. [Explanation of symbols]

[0050] 1: temperature history estimation device, 2: gear damper, 3: rubber ring, 10: data processing control unit, 20: memory unit, 30: operation unit, 40: notification unit, 50: interface unit, 101: measurement value reception unit, 102: temperature history estimation unit, 201: temperature history estimation program, 202: temperature sample data, 203: temperature history estimation result, 210, 211: TG-DTA curve, 300: measurement value reception screen, 301: measurement value input unit, 310: temperature history estimation result display screen, 311: estimation result display unit

Claims

1. An apparatus for estimating the temperature history of a measurement object which is a rubber composition, A measurement value receiving unit that receives a measurement value of the carbonization rate of the polymer contained in the measurement object; a storage unit that stores data showing a relationship between a carbonization rate of a polymer contained in the rubber composition sample and a temperature history; a temperature history estimation unit that estimates a temperature history of the measurement object based on the measured value of the carbonization rate and the data; Equipped with The measured value of the carbonization rate is a value obtained by measuring the amount of carbonization caused by structural change of the rubber composition due to its temperature history from the weight loss amount in the combustion region of the rubber composition.

2. A program executed by a computer to estimate the temperature history of a measurement object which is a rubber composition, Receiving a measurement value of a carbonization rate of a polymer contained in the measurement object; estimating the temperature history of the measurement object based on the measured value of the carbonization rate and data showing a relationship between the carbonization rate of the polymer contained in the rubber composition sample and the temperature history; causing the computer to execute A temperature history estimation program, wherein the measured value of the carbonization rate is a value obtained by measuring the amount of carbonization caused by structural change of the rubber composition due to its temperature history from the amount of weight loss in the combustion region of the rubber composition.

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