JP2012251068A - Manufacturing system of rubber composition and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing system of a rubber composition capable of eliminating air-in defects while suppressing reduction in productivity, and to provide a method for manufacturing the rubber composition.SOLUTION: The manufacturing system of a rubber composition containing silica and a silane coupling agent includes: a determination means which determines whether the predetermined amount of alcohol volatilizes or not during kneading; and a kneading finish means which finishes kneading at the time of determining the predetermined amount of alcohol has volatilized during kneading by the determination means. In the system, the predetermined amount is determined based on the Mooney viscosity of an unvulcanized rubber composition whose compounding is the same as that of the rubber composition.

Description

The present invention relates to a system for producing a rubber composition containing silica and a silane coupling agent, and a method for producing a rubber composition containing silica and a silane coupling agent.

Conventionally, a rubber composition containing silica has been blended with a silane coupling agent (for example, a silane coupling agent having an alkoxy group) that binds silica and a rubber component.

In Patent Document 1, when the kneading temperature is low, the reaction between the silica and the silane coupling agent becomes insufficient, and in the extrusion process performed after kneading, the moisture in the rubber and the unreacted silane coupling agent It is described that an alkoxy group reacts to generate an alcohol, which causes an air-in defect in which a porous material is generated in rubber.

On the other hand, in recent years, the kneading temperature has been increased and the kneading time has been increased in order to improve the wear resistance of the rubber composition containing silica. Along with this, the reaction rate of the silane coupling agent is improved, and it is expected that the air-in failure does not occur. However, in reality, an air-in failure may occur.

JP 2006-307044 A

An object of the present invention is to provide a rubber composition manufacturing system and a rubber composition manufacturing method capable of solving the above-described problems and eliminating air-in defects while minimizing a decrease in productivity.

The present invention is a system for producing a rubber composition containing silica and a silane coupling agent, wherein a judgment means for judging whether or not a predetermined amount of alcohol has volatilized during kneading, and the above judgment means during kneading A kneading end means for ending kneading when it is determined that a predetermined amount of alcohol has volatilized, and the predetermined amount is equal to the Mooney viscosity of an unvulcanized rubber composition blended with the rubber composition. The present invention relates to a rubber composition production system determined based on the above.

The rubber composition manufacturing system includes a calculation unit that calculates an amount of alcohol volatilized during kneading, and the determination unit volatilizes the predetermined amount of alcohol based on the alcohol amount calculated by the calculation unit. It is preferable to determine whether or not.

In the rubber composition manufacturing system, the calculation means includes a temperature history of the rubber composition during kneading, and a weight reduction rate at a plurality of temperatures of the rubber composition containing silica and a silane coupling agent, which are obtained in advance. Based on the above, it is preferable to calculate the amount of alcohol volatilized during kneading.

In the rubber composition manufacturing system, the calculating means calculates the temperature history of the rubber composition during kneading and the weight reduction rates at a plurality of temperatures of the rubber composition containing silica and a silane coupling agent, which have been acquired in advance. It is preferable to calculate the amount of alcohol volatilized during kneading based on the approximate expression obtained by plotting against temperature.

In the rubber composition production system, the approximate expression is preferably a linear expression.

The rubber composition manufacturing system includes an integration unit that integrates the alcohol amount calculated by the calculation unit, and the determination unit blends the alcohol amount integrated by the integration unit into the rubber composition being kneaded. It is determined whether the volatile alcohol ratio, which is a value divided by the upper limit of the amount of alcohol that can be generated during kneading, is calculated from the amount of the silane coupling agent that has been reached, and whether the predetermined value is The blending with the rubber composition is determined based on the Mooney viscosity of the same unvulcanized rubber composition, and the kneading end means is judged by the judging means that the volatile alcohol ratio has reached the predetermined value. It is preferable to terminate the kneading with this as an opportunity.

In the rubber composition manufacturing system, the rubber composition is preferably a tire rubber composition.

The present invention is also a method for producing a rubber composition containing silica and a silane coupling agent, wherein a judgment step for judging whether or not a predetermined amount of alcohol has volatilized during kneading, and during the kneading by the judgment step above. A kneading end step for ending kneading when it is determined that the predetermined amount of alcohol has volatilized, and the predetermined amount is the Mooney viscosity of an unvulcanized rubber composition blended with the rubber composition. The present invention relates to a method for producing a rubber composition determined based on the above.

The method for producing the rubber composition includes a calculation step for calculating an amount of alcohol volatilized during kneading, and the determination step includes volatilization of the predetermined amount of alcohol based on the alcohol amount calculated by the calculation step. It is preferable to determine whether or not.

In the method for producing the rubber composition, the calculation step includes a temperature history of the rubber composition during kneading, and a weight reduction rate at a plurality of temperatures of the rubber composition containing silica and a silane coupling agent, which are obtained in advance. Based on the above, it is preferable to calculate the amount of alcohol volatilized during kneading.

In the method for producing the rubber composition, the calculation step includes a temperature history of the rubber composition during kneading, and a weight reduction rate at a plurality of temperatures of the rubber composition containing silica and a silane coupling agent, which are obtained in advance. It is preferable to calculate the amount of alcohol volatilized during kneading based on the approximate expression obtained by plotting against temperature.

In the method for producing the rubber composition, the approximate expression is preferably a linear expression.

The method for producing the rubber composition includes an integration step of integrating the alcohol amount calculated in the calculation step, and the determination step mixes the alcohol amount integrated in the integration step with the rubber composition being kneaded. It is determined whether the volatile alcohol ratio, which is a value divided by the upper limit of the amount of alcohol that can be generated during kneading, is calculated from the amount of the silane coupling agent that has been reached, and whether the predetermined value is The blending with the rubber composition is determined based on the Mooney viscosity of the same unvulcanized rubber composition, and the kneading end step is determined by the determining step that the volatile alcohol ratio has reached the predetermined value. It is preferable to terminate the kneading with this as an opportunity.

In the method for producing the rubber composition, the rubber composition is preferably a tire rubber composition.

According to the present invention, there is provided a system for producing a rubber composition containing silica and a silane coupling agent, wherein judgment means for judging whether a predetermined amount of alcohol has volatilized during kneading, and kneading by the judgment means A kneading end means for ending kneading when it is determined that the predetermined amount of alcohol has volatilized, and the predetermined amount is a Mooney of an unvulcanized rubber composition having the same composition as the rubber composition. Since the rubber composition manufacturing system is determined based on the viscosity, air-in defects can be eliminated while minimizing the decrease in productivity.

Further, according to the present invention, there is provided a method for producing a rubber composition containing silica and a silane coupling agent, wherein a judgment step for judging whether a predetermined amount of alcohol has volatilized during kneading, and the judgment step A kneading end step for ending kneading when it is determined that the predetermined amount of alcohol has volatilized during kneading, and the predetermined amount is an unvulcanized rubber composition having the same composition as the rubber composition Since this is a method for producing a rubber composition determined on the basis of the Mooney viscosity, air-in defects can be eliminated while minimizing the decrease in productivity.

FIG. 1 is a diagram showing the relationship between “heat generation of rubber in the extrusion process” and “ratio of volatile alcohol” and the presence / absence of an expected air-in failure. FIG. 2 is a diagram showing an example of the relationship between the Mooney viscosity of an unvulcanized rubber composition and the heat generation of rubber in an extrusion process. FIG. 3 is a graph showing the relationship between “Mooney viscosity of unvulcanized rubber composition” and “ratio of volatile alcohol” and the presence / absence of expected air-in failure. FIG. 4 is a diagram showing an example of the results of thermogravimetric analysis (TGA) of an unvulcanized rubber composition. FIG. 5A is a diagram illustrating an example of a graph in which the rate of weight loss measured at each temperature is plotted against temperature. FIG. 5B is a diagram showing an example of a graph in which the weight loss rate measured at each temperature with different formulations is plotted against the temperature. FIG. 6 is a diagram showing an example of a kneading temperature chart showing the relationship between the temperature during kneading (the temperature of the rubber composition) and the kneading time. FIG. 7 is a diagram showing an example of a method for calculating the amount of volatilized alcohol based on the kneading temperature chart. FIG. 8A is a diagram summarizing an example of the relationship between the Mooney viscosity, the volatile alcohol ratio, and the presence or absence of occurrence of an air-in failure in an unvulcanized rubber composition. FIG. 8B is a diagram summarizing an example of the relationship between the Mooney viscosity, the volatile alcohol ratio, and the presence or absence of occurrence of an air-in failure in the unvulcanized rubber composition. FIG. 9 is a block diagram showing a part of the internal configuration of the Banbury mixer that constitutes the manufacturing system according to the embodiment of the present invention. FIG. 10 is a flowchart showing the input reception process performed in the Banbury mixer. FIG. 11 is a flowchart showing a volatile alcohol amount calculation process performed in the Banbury mixer. FIG. 12 is a flowchart showing a subroutine of volatile alcohol amount integration processing. FIG. 13 is a flowchart showing a subroutine of the kneading end determination process. FIG. 14 is a flowchart showing the kneading end process performed in the Banbury mixer.

First, an outline of the present invention will be described.
In the production of a rubber composition containing silica and a silane coupling agent, when the kneading temperature is increased and the kneading time is prolonged, from experience, by kneading at a higher temperature (kneading), air-in troubles I found that it can be resolved. However, there is no clear indication that how much refining can be done to eliminate air-in defects. It was.

Therefore, the present inventor has studied in detail the cause of the occurrence of an air-in failure. First, it was hypothesized that the air-in failure occurred due to the overlap of the following two factors.

(1) When the discharge temperature in the extrusion process is high, air-in troubles tend to occur. Therefore, it is presumed that “heat generation of rubber in the extrusion process” is a parameter related to the occurrence of an air-in failure.

(2) By increasing the kneading temperature and lengthening the kneading time, the reaction rate of the silane coupling agent is improved, the amount of alcohol produced increases, and it remains in the rubber without volatilizing during kneading. It is predicted that the amount of alcohol to be used is also increasing. And it is estimated that the alcohol remaining in this rubber may cause an air-in defect in an extrusion process or the like performed after kneading. Therefore, it is estimated that the amount of alcohol that volatilizes during kneading is one of the parameters related to the occurrence of air-in defects. Here, since the total amount of alcohol generated, which is the upper limit of the amount of alcohol that can be generated during kneading, can be calculated from the amount of silane coupling agent blended in the rubber composition, this parameter indicates the amount of alcohol that volatilizes during kneading. As described above, the “volatile alcohol ratio” obtained by dividing the amount of alcohol volatilized during kneading by the total amount of alcohol generated is used. That is, the volatile alcohol ratio indicates the ratio of alcohol that has already volatilized among the alcohols that can be generated during kneading. The total amount of alcohol generated can be calculated from the type of silane coupling agent added and its amount.

FIG. 1 is a diagram showing the relationship between the above two parameters (“rubber heat generation in the extrusion process” and “volatile alcohol ratio”) and the presence or absence of an expected air-in failure. If the presence or absence of an air-in failure can be clearly distinguished by the above two parameters, the above two parameters will be clear indicators for eliminating the air-in failure.

Here, since “rubber heat generation in the extrusion process” is not a general parameter to be used as an index, examination was made to change “rubber heat generation in the extrusion process” to a general parameter.

Therefore, a rubber composition containing silica and a silane coupling agent having an alkoxy group was kneaded to prepare an unvulcanized rubber composition. Similarly, the composition was changed to prepare a plurality of unvulcanized rubber compositions having different compositions. And according to JIS K 6300-1, “Unvulcanized rubber-physical properties—Part 1: How to determine viscosity and scorch time by Mooney viscometer” for each unvulcanized rubber composition obtained, The measurement was performed at a temperature of 130 ° C. Furthermore, these unvulcanized rubber compositions were subjected to an extrusion process, the discharge temperature in the extrusion process (that is, the heat generation of rubber in the extrusion process) was measured, and the presence or absence of occurrence of an air-in failure was also investigated. The obtained results are shown in FIG. From FIG. 2, it was found that there is a correlation between the Mooney viscosity of the unvulcanized rubber composition and the heat generation of the rubber in the extrusion process regardless of the blending content. In this specification, when the Mooney viscosity is simply described as the Mooney viscosity of the unvulcanized rubber composition, the unvulcanized rubber composition measured under the temperature condition of 130 ° C. according to JIS K 6300-1. Means Mooney viscosity.

Thereby, the “heat generation of rubber in the extrusion process” in FIG. 1 can be replaced with “the Mooney viscosity of the unvulcanized rubber composition”. That is, the “volatile alcohol ratio” and the “Mooney viscosity of the unvulcanized rubber composition” are parameters that are expected to be related to the occurrence of air-in defects. FIG. 3 shows the relationship between these parameters and the expected occurrence of air-in failure. If these parameters can clearly classify whether or not an air-in failure has occurred, these parameters will be a clear indicator for eliminating the air-in failure.

Next, since it is difficult to directly measure the amount of alcohol that volatilizes during kneading, studies were made to make it possible to estimate the amount of alcohol that volatilizes during kneading.

First, a rubber composition containing silica and a silane coupling agent having an alkoxy group was kneaded to prepare an unvulcanized rubber composition. And the thermogravimetric analysis (TGA) was performed about the obtained unvulcanized rubber composition. Specifically, the mass change at 150 ° C. of the obtained unvulcanized rubber composition was measured. Then, as shown in FIG. 4, the results were linearly approximated to calculate the rate of weight loss at 150 ° C. (that is, the volatilization rate of alcohol). Similar experiments were performed at 130 ° C and 170 ° C. The thermogravimetric analysis was performed using TGA-50 manufactured by Shimadzu Corporation. FIG. 5A shows an example of a graph in which the weight loss rate measured at each temperature is plotted against the temperature. As shown in FIG. 5A, when an approximate line was drawn, approximation was possible using a linear expression. In addition, the same experiment was performed by changing the blending of the amount of silica and the like, and the weight loss rate measured at each temperature was plotted against the temperature, and was able to be approximated by almost the same linear equation regardless of the blending (FIG. 5B). ). Thus, it was confirmed that the above approximate expression does not need to be changed even if the composition is changed. In addition, since it can be approximated by a linear expression, the amount of volatile alcohol can be easily calculated.

In this experiment, the rate of weight loss at each temperature (that is, the volatilization rate of alcohol) was measured under static conditions where the rubber composition was allowed to stand. However, the volatilization rate of alcohol should not change even under dynamic conditions such as during kneading. For example, this approximate expression can be used to calculate the amount of alcohol that volatilizes during kneading. The inventor confirmed that the result of the static condition and the result of the dynamic condition have a correlation, and confirmed that the amount of alcohol volatilized during kneading can be calculated using the above approximate expression.

Specifically, the amount of alcohol that volatilizes during kneading may be calculated, for example, by the following procedure. FIG. 6 is a diagram showing an example of a kneading temperature chart showing the relationship between the temperature during kneading (the temperature of the rubber composition) and the kneading time. The kneading temperature chart represents the temperature history of the rubber composition during kneading. This temperature history is divided, for example, in units of 10 seconds (FIG. 7), and the amount of alcohol volatilized in 10 seconds can be calculated by the integration method using the above approximate expression. And the alcohol total amount which shows the total amount of the alcohol volatilized during kneading | mixing can be calculated by integrating the calculated alcohol amount. According to this method, the amount of alcohol volatilized in real time and the total amount of alcohol volatilized during kneading can be grasped.

Next, the rubber composition containing the silica and the silane coupling agent having an alkoxy group is actually kneaded, the total amount of alcohol volatilized during the kneading is calculated by the above method, and the volatile alcohol ratio is calculated from the blended silane coupling agent amount. Calculated. And the Mooney viscosity of each obtained unvulcanized rubber composition was measured on 130 degreeC temperature conditions according to JISK6300-1. Furthermore, the unvulcanized rubber composition was subjected to an extrusion process, and the presence or absence of occurrence of an air-in defect was investigated. A similar experiment was conducted by changing the composition of the rubber composition.

Based on the obtained results, the Mooney viscosity, the volatile alcohol ratio, and the presence or absence of occurrence of air-in defects in the unvulcanized rubber composition are summarized in FIG. 8A. From this result, as shown in FIG. 8B, it was found that the two parameters of the Mooney viscosity and the volatile alcohol ratio of the unvulcanized rubber composition are clear indicators for eliminating the air-in defect.

For example, when the Mooney viscosity of the unvulcanized rubber composition is 60, the occurrence of an air-in failure can be suppressed by kneading until the volatile alcohol ratio (mass basis) becomes 0.23 or more. That is, when the Mooney viscosity of the unvulcanized rubber composition is 60, the predetermined value may be set to 0.23, for example.

The present inventor has confirmed that this method can also be applied to an actual machine in a factory. From the above examination results, a rubber composition containing silica and a silane coupling agent in an actual machine is obtained by measuring the Mooney viscosity of an unvulcanized rubber composition having the same composition as the rubber composition to be manufactured in advance on a laboratory scale. Since the kneading | mixing target which can suppress generation | occurrence | production of an air-in defect when manufacturing this becomes clear, generation | occurrence | production of an air-in defect can be suppressed without reducing productivity. Therefore, even when the composition of the rubber composition is changed, the kneading target for manufacturing with an actual machine becomes clear by measuring the Mooney viscosity of the unvulcanized rubber composition in advance on a lab scale. The labor when changing the composition can be reduced. Moreover, the kneading process can be analyzed by this method. Further, the present invention can be suitably applied to a tire rubber composition.

Next, an embodiment of the present invention will be described.
FIG. 9 is a block diagram showing a part of the internal configuration of the Banbury mixer that constitutes the manufacturing system according to the embodiment of the present invention.
The Banbury mixer 10 includes a CPU 41, a ROM 42, a RAM 43, a hard disk 44, a timer 45, a graphic board 47, an image display panel 48, a touch panel 46, and a temperature sensor 49. The Banbury mixer 10 has a configuration that is conventionally provided in a Banbury mixer such as a rotor drive circuit that controls the rotation of the rotor based on a signal output from the rotor or the CPU 41, but FIG. For the sake of clarity, these conventional configurations are omitted.

The ROM 42 stores a system program for controlling the operation of the Banbury mixer, permanent data, and the like.

The timer 45 is used for measuring time, and transmits data indicating the measured time to the CPU 41 at predetermined time intervals. The temperature sensor 49 is used for measuring the temperature during kneading (the temperature of the rubber composition), and transmits data indicating the measured temperature to the CPU 41 at predetermined time intervals.

The graphic board 47 controls image display on the image display panel 48 based on a control signal output from the CPU 41. On the image display panel 48, an image for prompting the input of the blended silane coupling agent amount and Mooney viscosity is displayed.

The touch panel 46 is provided on the front surface of the image display panel 48, and the operator of the Banbury mixer 10 can input various instructions by operating the touch panel 46.

The hard disk 44 associates the data received from the timer 45 with the data received from the temperature sensor 49 and stores it in the RAM 43 as temperature history data indicating the temperature history during kneading (temperature history data creation program), blending Program for calculating total alcohol generation from the amount of silane coupling agent (total alcohol generation calculation program), data defining the relationship between Mooney viscosity and volatile alcohol ratio (predetermined value) as a kneading target, Mooney input Program for determining a predetermined value based on viscosity data (predetermined value determination program), approximate expression data defining a linear expression approximating the relationship between temperature and weight loss rate (volatilization rate of alcohol), temperature history data and approximate expression Program to calculate the amount of volatile alcohol from the data (volatile alcohol Calculation program), and the like. These data and programs are read into the RAM 43 at a predetermined timing and executed.

When an image based on the temperature history data is displayed on the image display panel 48, for example, an image as shown in FIG. 6 is displayed. The data defining the relationship between the Mooney viscosity and the volatile alcohol ratio (predetermined value) as a kneading target is specifically data defining the primary expression depicted in FIG. 8B. The approximate expression data that defines the linear expression that approximates the relationship between the temperature and the rate of weight loss (the volatilization rate of alcohol) is specifically data that defines the primary expression depicted in FIG. 5A.

The RAM 43 includes data indicating the amount of silane coupling agent (silane coupling agent amount data), data indicating the value of Mooney viscosity (Mooney viscosity data), temperature history data, and data indicating the total alcohol generation amount (total alcohol generation amount data). ), Data indicating predetermined values (predetermined value data), data indicating volatile alcohol amount (volatile alcohol amount data), data indicating total alcohol amount (alcohol total amount data), data indicating volatile alcohol ratio (volatile alcohol ratio data), etc. Temporarily store various data.

FIG. 10 is a flowchart showing the input reception process performed in the Banbury mixer.
The input acceptance process is called and executed at a predetermined timing such as before the rubber composition containing silica and the silane coupling agent is started by the Banbury mixer 10.

First, the CPU 41 displays an input acceptance screen on the image display panel 48 (step S1). In this process, the CPU 41 transmits a control signal to the graphic board 47 and controls the image display panel 48 to display the input acceptance screen.
On the input reception screen, an image for prompting input of the amount of the silane coupling agent blended and the Mooney viscosity of the unvulcanized rubber composition is displayed.

Next, the CPU 41 determines whether or not the value of the blended silane coupling agent amount has been input (step S2). In this process, the CPU 41 determines whether or not data (silane coupling agent amount data) indicating the amount of silane coupling agent blended from the touch panel 46 has been received. When determining that the value of the blended silane coupling agent amount has not been input, the CPU 41 returns the process to step S1.

On the other hand, if it is determined that the value of the blended silane coupling agent amount has been input, the CPU 41 determines whether or not the Mooney viscosity value of the unvulcanized rubber composition having the same blend as the rubber composition to be kneaded is input. Is determined (step S3). In this process, the CPU 41 determines whether or not data (Mooney viscosity data) indicating the value of the Mooney viscosity of the unvulcanized rubber composition has been received from the touch panel 46. When determining that the Mooney viscosity value has not been input, the CPU 41 returns the process to step S1.

On the other hand, when determining that the Mooney viscosity value has been input, the CPU 41 calculates the total amount of alcohol generated (step S4). In this process, the CPU 41 reads out and executes the total alcohol generation amount calculation program stored in the hard disk 44 to the RAM 43, and calculates the total alcohol generation amount from the silane coupling agent amount data received from the touch panel 46. Then, the CPU 41 stores data (total alcohol generation amount data) indicating the calculated total alcohol generation amount in the RAM 43 (step S5).

Next, the CPU 41 determines a predetermined value (step S6). In this process, the CPU 41 reads out and executes a predetermined value determination program stored in the hard disk 44 to the RAM 43, executes the Mooney viscosity data received from the touch panel 46, the Mooney viscosity and the volatile alcohol ratio (predetermined value) as a kneading target. The predetermined value is determined based on the data defining the relationship. Then, the CPU 41 stores data (predetermined value data) indicating the determined predetermined value in the RAM 43 (step S7).

Next, the CPU 41 sets a kneading start flag (step S8). When the kneading start flag is set, the kneading process is executed. Since this kneading process is a process conventionally performed in a Banbury mixer, detailed description is omitted, but the CPU 41 transmits a signal to the rotor drive circuit to control the rotation of the rotor, and the rubber composition. Kneading is performed. When the kneading start flag is set, the timer 45 starts measuring time. Further, a temperature history data creation program is executed, and the data received from the timer 45 and the data received from the temperature sensor 49 are associated with each other and stored in the RAM 43 as temperature history data indicating the temperature history during kneading. CPU41 complete | finishes an input reception process, after performing the process of step S8.

FIG. 11 is a flowchart showing a volatile alcohol amount calculation process performed in the Banbury mixer.
In this embodiment, the volatile alcohol amount calculation process is called and executed every 10 seconds.

First, the CPU 41 calculates the amount of volatile alcohol that has volatilized during 10 seconds from when the previous volatile alcohol amount calculation process is called to when this volatile alcohol amount calculation process is called (step S11). In this process, the CPU 41 reads out and executes the volatile alcohol amount calculation program stored in the hard disk 44 to the RAM 43 and calculates the volatile alcohol amount from the temperature history data and the approximate expression data. Specifically, the temperature history data is divided into units of 10 seconds, and the amount of alcohol volatilized in 10 seconds from when the previous volatile alcohol amount calculation process is called to when this volatile alcohol amount calculation process is called is approximated. Calculated by integration method using formula data. And CPU41 memorize | stores the data (volatile alcohol amount data) which show the calculated amount of volatile alcohol in RAM43 (step S12). When executing the process of step S11, the CPU 41 functions as a calculation unit.

Next, the CPU 41 executes a volatile alcohol amount integration process (step S13). In this process, based on the volatile alcohol amount calculated in step S11, an alcohol total amount indicating the total amount of alcohol volatilized during kneading is calculated, and a volatile alcohol ratio is calculated. The volatile alcohol amount integration process will be described later with reference to the drawings. CPU41 complete | finishes the amount calculation process of volatile alcohol, after performing the process of step S13.

FIG. 12 is a flowchart showing a subroutine of volatile alcohol amount integration processing.
First, the CPU 41 performs integration processing (step S21). In this process, the CPU 41 adds the numerical value indicated by the volatile alcohol amount data stored in the RAM 43 in step S12 to the numerical value indicated by the data indicating the total alcohol amount (alcohol total amount data) stored in the RAM 43. When the total alcohol amount data is not stored in the RAM 43, the numerical value indicated by the volatile alcohol amount data stored in the RAM 43 is added to 0 in step S12. Then, the numerical value obtained by the addition is stored in the RAM 43 as new alcohol total amount data (step S22). Further, the volatile alcohol amount data stored in the RAM 43 is cleared in step S12. When executing the process of step S21, the CPU 41 functions as an integrating means.

Next, the CPU 41 calculates a volatile alcohol ratio (step S23). In this process, the CPU 41 calculates the volatile alcohol ratio by dividing the numerical value indicated by the total alcohol amount data stored in the RAM 43 by the numerical value indicated by the total alcohol generation amount data stored in the RAM 43. Then, the CPU 41 stores data indicating the calculated volatile alcohol ratio (volatile alcohol ratio data) in the RAM 43 (step S24).

Next, the CPU 41 executes a kneading end determination process (step S25). In this process, it is determined whether or not the volatile alcohol ratio calculated in step S23 exceeds a predetermined value, and it is determined whether or not a predetermined amount of alcohol has volatilized during kneading. The kneading end determination process will be described later with reference to the drawings. After executing the process of step S25, the CPU 41 ends the volatile alcohol amount integration process.

FIG. 13 is a flowchart showing a subroutine of the kneading end determination process.
First, the CPU 41 determines whether or not the volatile alcohol ratio is greater than a predetermined value (step S31). In this process, the CPU 41 determines whether or not the numerical value indicated by the volatile alcohol ratio data stored in the RAM 43 in step S24 is larger than the numerical value indicated by the predetermined value data stored in the RAM 43 in step S7. When determining that the volatile alcohol ratio is not greater than the predetermined value, the CPU 41 ends the kneading end determination process. When executing the process of step S31, the CPU 41 functions as a determination unit.

On the other hand, when determining that the volatile alcohol ratio is greater than the predetermined value, the CPU 41 sets a kneading end flag (step S32) and ends the kneading end determination process.

FIG. 14 is a flowchart showing the kneading end process performed in the Banbury mixer.
The kneading end process is called and executed at a predetermined timing after the rubber composition 10 starts to knead the rubber composition.

First, the CPU 41 determines whether or not a kneading end flag is set (step S41). When determining that the kneading end flag is not set, the CPU 41 ends the kneading end process.

On the other hand, when determining that the kneading end flag is set, the CPU 41 ends kneading (step S42). In this process, the CPU 41 transmits a signal to the rotor drive circuit and stops the rotation of the rotor. Further, the CPU 41 clears the total alcohol amount data, the volatile alcohol ratio data, the kneading start flag, and the kneading end flag. CPU41 complete | finishes a kneading | mixing completion process, after performing the process of step S42. When executing the processes of step S41 and step S42, the CPU 41 functions as a kneading end means.

As described above, according to the production system (Banbury mixer 10) and the production method in the present embodiment, in the production of a rubber composition containing silica and a silane coupling agent, the total amount of alcohol indicating the total amount of alcohol volatilized during kneading is obtained. The volatile alcohol ratio, which is a value divided by the total amount of alcohol generated, which is the upper limit of the amount of alcohol that can be generated during kneading, is the Mooney viscosity of an unvulcanized rubber composition that has the same composition as the rubber composition to be produced. The kneading is terminated when it is determined that the predetermined value determined based on the determination is reached. That is, kneading is terminated when it is determined that an amount of alcohol determined based on the Mooney viscosity of an unvulcanized rubber composition having the same composition as the rubber composition to be produced has volatilized during kneading. . Therefore, it is possible to eliminate the air-in defect while minimizing the decrease in productivity.

In the present embodiment, the case where the present invention is applied to a Banbury mixer has been described, but the present invention can also be applied to other kneaders (for example, a kneader, an extruder).

In the present embodiment, the case where the manufacturing system is configured by the Banbury mixer 10 has been described. However, the manufacturing system may be configured by a kneading machine and a control device connected to the kneading machine via a communication line. .
In this case, for example, the control device 100 includes a CPU 141, a ROM 142, a RAM 143, and a hard disk 144. The Banbury mixer 10 that is a kneading machine includes a CPU 41, a ROM 42, a RAM 43, a hard disk 44, and a timer. 45, a graphic board 47, an image display panel 48, a touch panel 46, and a temperature sensor 49. Then, the CPU 41 included in the Banbury mixer 10 transmits temperature history data and the like to the CPU 141 included in the control device 100 at a predetermined timing. Then, the CPU 141 included in the control device 100 calculates a total amount of alcohol indicating the total amount of alcohol volatilized during kneading based on the received temperature history data, further calculates a volatile alcohol ratio, and the volatile alcohol ratio is predetermined. When it is determined that the value has been exceeded, a signal notifying the end of kneading is transmitted to the CPU 41 provided in the Banbury mixer 10. And CPU41 with which the Banbury mixer 10 which received this signal should just perform the process which complete | finishes kneading | mixing.

In the present embodiment, the case where the amount of volatile alcohol is calculated from the temperature history data and the approximate expression data has been described. However, in the present invention, the amount of volatile alcohol is determined based on the temperature history data and the rate of reduction at a plurality of temperatures. ) May be calculated from a table stored in association with each temperature.

In the present embodiment, the case where the ratio of volatile alcohol is used as an index for kneading has been described. It is good also as ending kneading | mixing with an opportunity. The predetermined amount, which is a kneading completion index, can be calculated from, for example, a predetermined value and the total alcohol generation amount.

The embodiment of the present invention has been described above, but only specific examples are illustrated, and the present invention is not particularly limited. The specific configuration of each unit and the like can be appropriately changed. The effects described in the embodiments of the present invention are only the most preferable effects resulting from the present invention, and the effects of the present invention are limited to those described in the embodiments of the present invention. is not.

10 Banbury mixer 41 CPU
42 ROM
43 RAM
44 Hard disk 45 Timer 46 Touch panel 47 Graphic board 48 Image display panel 49 Temperature sensor

Claims (14)

A system for producing a rubber composition comprising silica and a silane coupling agent,
A judging means for judging whether or not a predetermined amount of alcohol volatilizes during kneading;
Kneading end means for ending kneading when the determination means determines that the predetermined amount of alcohol has volatilized during kneading,
A system for producing a rubber composition, wherein the predetermined amount is determined on the basis of the Mooney viscosity of an unvulcanized rubber composition having the same composition as the rubber composition. A calculation means for calculating the amount of alcohol volatilized during kneading,
The rubber composition manufacturing system according to claim 1, wherein the determination unit determines whether the predetermined amount of alcohol has volatilized based on the amount of alcohol calculated by the calculation unit. The calculation means volatilized during kneading based on the temperature history of the rubber composition being kneaded and the weight loss rates at a plurality of temperatures of the rubber composition containing silica and the silane coupling agent that were acquired in advance. The rubber composition production system according to claim 2, wherein the amount of alcohol is calculated. The calculation means is obtained by plotting the temperature history of the rubber composition during kneading and the weight reduction rates at a plurality of temperatures of the rubber composition containing silica and a silane coupling agent, which have been acquired in advance, against temperature. The rubber composition manufacturing system according to claim 2 or 3, wherein the amount of alcohol volatilized during kneading is calculated based on the approximate expression. The system for producing a rubber composition according to claim 4, wherein the approximate expression is a linear expression. Integrating means for integrating the amount of alcohol calculated by the calculating means;
The determination means divides the amount of alcohol accumulated by the accumulation means by the upper limit of the amount of alcohol that can be generated during kneading, calculated from the amount of the silane coupling agent blended in the rubber composition being kneaded. Determine whether the volatile alcohol ratio that is the value has reached a predetermined value,
The predetermined value is determined based on the Mooney viscosity of an unvulcanized rubber composition having the same composition as the rubber composition;
The rubber composition production system according to any one of claims 2 to 5, wherein the kneading end means ends the kneading when the determination means determines that the volatile alcohol ratio has reached the predetermined value. . The rubber composition production system according to any one of claims 1 to 6, wherein the rubber composition is a tire rubber composition. A method for producing a rubber composition comprising silica and a silane coupling agent,
A determination step of determining whether or not a predetermined amount of alcohol has volatilized during kneading;
A kneading end step for ending kneading when it is determined that the predetermined amount of alcohol has volatilized during kneading during the determining step,
The method for producing a rubber composition, wherein the predetermined amount is determined based on the Mooney viscosity of an unvulcanized rubber composition having the same composition as the rubber composition. Including a calculation step of calculating the amount of alcohol volatilized during kneading,
The method for producing a rubber composition according to claim 8, wherein the determination step determines whether or not the predetermined amount of alcohol has volatilized based on the amount of alcohol calculated in the calculation step. The calculation step volatilized during the kneading based on the temperature history of the rubber composition being kneaded and the weight reduction rates at a plurality of temperatures of the rubber composition containing silica and the silane coupling agent that were previously acquired. The method for producing a rubber composition according to claim 9, wherein the amount of alcohol is calculated. The calculation step is obtained by plotting the temperature history of the rubber composition during kneading and the weight reduction rates at a plurality of temperatures of the rubber composition containing silica and a silane coupling agent, which have been acquired in advance, against temperature. The method for producing a rubber composition according to claim 9 or 10, wherein the amount of alcohol volatilized during kneading is calculated based on the approximate expression. The method for producing a rubber composition according to claim 11, wherein the approximate expression is a linear expression. An integration step of integrating the amount of alcohol calculated by the calculation step,
In the determination step, the amount of alcohol integrated in the integration step is divided by the upper limit of the amount of alcohol that can be generated during kneading, which is calculated from the amount of the silane coupling agent blended in the rubber composition being kneaded. Determine whether the volatile alcohol ratio that is the value has reached a predetermined value,
The predetermined value is determined based on the Mooney viscosity of an unvulcanized rubber composition having the same composition as the rubber composition;
The method for producing a rubber composition according to any one of claims 9 to 12, wherein the kneading end step ends kneading when it is determined by the determining step that the volatile alcohol ratio has reached the predetermined value. . The method for producing a rubber composition according to any one of claims 8 to 13, wherein the rubber composition is a tire rubber composition.

Images