JPH0229984B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a reaction amount measuring device,
More specifically, the present invention relates to an apparatus for automatically measuring the amount of a chemical reaction such as a rubber vulcanization reaction or a polymer material curing reaction.

Generally, in the chemical industry, controlling the reaction process to increase reaction efficiency, product quality, and yield is an extremely important fundamental issue, and various measuring instruments and control mechanisms are used in combination to achieve this control. ing.

One of the most important issues in chemical reaction processes is the measurement of the reaction amount, which is determined by the reaction rate, reaction temperature, and reaction time. Conventionally, measuring the reaction amount requires complicated and large equipment. There was a desire to develop a small, portable device that could be easily used on the factory floor.

The present invention relates to a reaction amount measuring device that satisfies the above-mentioned needs, and more specifically, it is possible to simultaneously measure the temperature of the reaction system and the reaction amount by simply inserting a temperature sensing part into the reaction system at a work site. This invention relates to a small-sized reaction amount measuring device that can be displayed digitally.

Conventionally, in chemical reactions, particularly rubber vulcanization reactions and polymeric material curing reactions, the amount of reaction has been measured by direct chemical analysis of the reaction composition, and indirectly by measuring the reaction amount at a certain reference temperature within a certain period of time. There is a method of determining the relative reaction amount to the reaction amount, and the apparatus of the present invention is based on the principle of the latter indirect method.

That is, based on the Arrhenius reaction rate equation in a chemical reaction, the relative reaction amount (equivalent reaction amount) at a certain temperature is determined by the following equation (1) or its approximate equation (2).

In each of the above equations, U: equivalent reaction amount E: activation energy R: gas constant T: temperature T ₀ : reference temperature α: temperature coefficient t: time. Using equation (1) or equation (2), the ratio of the reaction amount after t time at the temperature T of the reaction system to the reference reaction amount per unit time at the reference temperature _T0 , that is, the relative reaction amount is determined. To actually use these equations, measure the temperature of the reaction system at regular time intervals, substitute the temperature value into equation (1) or (2), and calculate the equivalent reaction amount at each measurement point. .
For this reason, conventionally, the temperature measured with a portable digital thermometer is recorded on a paper tape (or magnetic tape), this is input into a suitable computer, and the calculated reaction amount is displayed on a printer. However, such a method has the disadvantage that temperature measurement and calculation of the equivalent reaction amount cannot be performed simultaneously. The present invention eliminates such drawbacks and provides a device that can measure temperature and read changes over time in the equivalent reaction amount at a glance.The device of the present invention eliminates the necessary response work for reactions. can be done immediately.

Next, the principle of the apparatus of the present invention will be explained with reference to FIG. 1-1.

First, the thermocouple 1, which forms the temperature sensing part of the device of the present invention, is inserted into the temperature measuring position of the reaction system, and the electromotive force (for example, several mV) generated in the thermocouple is transferred to the amplifier linearizer 2.
The width is increased and linearized by . For example, the voltage sent out from amplifier linearizer 2 is 0V at 0℃, and 200℃
The voltage becomes 2V, and the relationship between temperature and voltage becomes linear. Next, the voltage signal output from the amplifier linearizer is converted into a digital temperature signal by the A/D converter 3. For example, 2V is 200.0
℃, 1.567V becomes 156.7℃. The digitized signal is digitally displayed via the driver 4 on the temperature display 5 (LED, neon tube, liquid crystal, etc.) corresponding to each digit of the temperature value, so this display shows the reaction system at each measurement point. temperature can be read.

The signals digitized by the A/D converter are simultaneously input to the microcomputer 7 on the other hand. The microcomputer 7 has a read-only memory (hereinafter referred to as ROM) for storing programs, a random access memory (hereinafter referred to as RAM) as a work area, necessary input/output terminals (hereinafter referred to as I/O), and a start signal 9. When detected, the temperature signal digitized by the timer circuit 6 is read at regular time intervals, the reference temperature and activation energy are also read, and the reaction amount is calculated using equation (1) or (2). , program it to output.

When the start button 9 is turned on, the microcomputer reads the signal (temperature) digitized by the A/D converter 3 using pulses sent from the timer circuit 6 at fixed time intervals (for example, every 6 seconds) and (1) The cumulative equivalent reaction amount is calculated using the formula or formula (2). Which equation (1) or (2) to use is determined in advance by a microcomputer program. Further, the reference temperature T ₀ is set by the digital switch 13, and the activation energy E is set by the digital switch 11. The calculated cumulative equivalent reaction amount is output from the microcomputer as a digital amount, and is displayed on the display 14 corresponding to each digit of the calculated value via the input/output device 8.
It is displayed (by LED, neon tube, liquid crystal, etc.) each time a calculation is performed (for example, the value changes every 6 seconds).
In this way, the equivalent reaction amount at each temperature measurement point can be determined. Various thermometers, such as thermocouples and platinum resistors, can be used as the temperature-sensing section, but as mentioned above, thermocouples are preferred because they are convenient and highly accurate. The flow chart of Figure 1-1 is shown in Figure 1-12.

Next, a specific embodiment of the apparatus will be shown with reference to FIGS. 1-2.

Embodiment In the embodiment of the apparatus of the present invention shown in Fig. 1-2, block 1 is the thermocouple 1 of Fig. 1-1, and block 2 is the amplifier linearizer 2 of Fig. 1-1.
Block 3 corresponds to the A/D converter 3, driver 4, and temperature display 5 in FIG. 1-1, and block 4 corresponds to 6 to 14 in FIG. 1-1.

Block 1 is a thermocouple, block 2 is a temperature converter, block 3 is a digital voltmeter, and block 4 is a microcomputer. Many types of components and circuits are known, but by combining them as shown in the figure, the purpose can be achieved. The reaction amount can be measured accurately, inexpensively, and quickly.

In addition, in FIG. 1-2, the numbers 14433, 14513, 1413, 8748, 8243, and 74246 shown in each block mean the names of commercially available IC circuits.

Application examples of controlling chemical reactions using the apparatus of the present invention will be described below.

Application example 1 Measuring the amount of rubber reaction during rubber vulcanization Changes in the torque value of vulcanized rubber at each vulcanization temperature (130°C, 140°C, 150°C, 160°C) were measured using a rheometer and are shown in Figure 2. Draw a torque curve like this, and find the optimal vulcanization (90% vulcanization) time from each torque curve. Next, draw Figure 3 using Arrhenius equation (1) and give the activation energy value E (25.0 Kcal/mol).
seek. Generally, when vulcanizing a thick object such as a tire, vulcanization is slower on the inside than on the surface, and the properties of the vulcanized product are significantly deteriorated, but excessive vulcanization may result. However, in order to prevent insufficient vulcanization from occurring in the shortest possible time, vulcanization should be controlled so that the part where vulcanization is delayed the most will reach optimal vulcanization. is preferred.

Next, the apparatus of the present invention is connected to a power source at an actual vulcanization site, and a thermocouple is inserted into the part where vulcanization is slowest. Set the previously determined activation energy value in the device. When the vulcanizer is closed and the apparatus is started at the same time as vulcanization starts, the temperature of the vulcanized rubber and the amount of vulcanization reaction are sequentially digitally displayed as time passes.

Application example 2 Measurement of the optimal vulcanization time in rubber vulcanization The activation energy value E was determined in the same manner as application example 1.
Find (25.0Kcal/mol). On the other hand, use a rheometer to draw the vulcanization time/torque curve of the vulcanized rubber at a constant reference temperature (150°C) to determine the optimum vulcanization amount a (25 units) (see Figure 4).

Next, the apparatus of the present invention is connected to a power source at the vulcanization site, and a thermocouple is inserted, for example, at the part where vulcanization is slowest. Set the previously determined activation energy value in the device. When the apparatus is started at the same time as vulcanization begins, the amount of vulcanization reaction that changes over time is sequentially displayed digitally. The optimum vulcanization time can be obtained by knowing the time when this display amount reaches the previously determined optimum vulcanization a. In other words, as shown in Figure 5, the temperature-time curve of vulcanization temperature (left vertical axis) and vulcanization time (horizontal axis) and the time-vulcanization amount curve of vulcanization amount (right vertical axis) and vulcanization time are plotted. If the vulcanization time when the optimum vulcanization amount a is reached is determined from the curve, the optimum vulcanization time t can be obtained.

Application example 3 Application to automatic control The vulcanization temperature-vulcanization time curve obtained in application example 2 is used. That is, vulcanization is performed by outputting the optimum vulcanization time t until reaching the optimum vulcanization value a shown on the right vertical axis in FIG. The progress can be automatically controlled.

Although an application example of the apparatus of the present invention has been described above for vulcanization of rubber, it goes without saying that it can also be applied to curing reactions of other polymeric materials. Furthermore, according to the device of the present invention, changes over time in the temperature of the reaction system and the amount of reaction can be grasped at a glance through the digital display, and the reaction can be responded to immediately; similar to conventionally used digital portable thermometers. The equivalent reaction amount can be measured extremely easily by simply inserting a heat-sensitive part (e.g., a thermocouple) into the reaction system; it is small, lightweight, and portable, and can be connected to a large computer, etc. like the conventional method. It has excellent advantages such as being able to be used on site at any desired time without having to do any work; and being inexpensive to manufacture.

[Brief explanation of drawings]

Fig. 1-1 is a block diagram showing the configuration of the reaction amount measuring device according to the present invention, Fig. 1-12 is a flowchart thereof, and Fig. 1-2 explains an embodiment of the device of the present invention. Figure 2 is a graph showing the torque value vs. vulcanization time curve of a vulcanized tire, Figure 3 is a graph for determining the activation energy in the tire vulcanization reaction, and Figure 4 is a graph for determining the activation energy in the tire vulcanization reaction. is a graph showing changes in torque value and vulcanization amount of vulcanized rubber, and FIG. 5 is a graph for determining the optimum vulcanization time. Symbols in the figure: 1... thermocouple, 2... amplifier linearizer, 3... A/D converter, 4... driver, 5... temperature display, 6... timer circuit, 7... microcomputer, 8... input/output device, 9... Start button, 10...Input/output interface,
11...Digi switch, 12...Input/output interface, 13...Digi switch, 14...Equivalent reaction amount display.

Claims (1)

[Claims] 1. A temperature measurement display section that measures and digitally converts the voltage signal generated in the temperature sensing section placed in the reaction system;
A microcomputer that calculates the equivalent reaction amount by inputting a preset activation energy value, a reference temperature value, and the measured voltage signal, a timer that causes the microcomputer to perform calculations at fixed time intervals, and a microcomputer that calculates the equivalent reaction amount. What is claimed is: 1. A reaction amount measuring device comprising a reaction amount display section for displaying an equivalent reaction amount, and characterized in that it is small and portable.