JP2007216471A - System for kneading silica-incorporated rubber material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a system for kneading a silica-incorporated rubber material which stabilizes quality by improving the dispersibility of silica, can obtain rubber with target viscosity in a short time, and is superior in productivity. <P>SOLUTION: A process for obtaining finally kneaded rubber RF from a closed type kneader 1 by a final kneader 19 is carried out continuously. In a reaction promoting kneader 5 composed in a roll kneader of an open structure, while primarily kneaded rubber R1 is kneaded while components such as an alcohol produced by the coupling reaction between silica and a coupling agent are diffused outside, the coupling reaction is promoted by carrying out kneading while a necessary heat quantity is given to the primarily kneaded rubber R1 exposed to outside air by a heater 7. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a silica-mixed rubber material kneading system. More specifically, the silica dispersibility is improved to stabilize the quality, and the productivity of obtaining a rubber having a target viscosity in a short time is excellent. The present invention relates to a kneading system for silica compounded rubber material.

  In the tire tread rubber and the like, the low-fuel-consumption property and wet grip property of the tire are improved by using a silica-containing rubber compounded with silica. However, since silica easily aggregates between particles, the dispersibility of the rubber material is poor, and the dispersibility is improved by incorporating a silane coupling agent and causing a coupling reaction with silica.

  In order to improve the dispersibility of silica by using a silane coupling agent, it is necessary to complete the coupling reaction, and for this purpose, kneading must be performed while applying a necessary amount of heat.

  When such a silica compounded rubber material is kneaded by a closed kneader called a Banbury mixer, the rubber temperature rises excessively due to heat generated by friction during kneading, so the upper limit temperature limit of the rubber material Therefore, it was difficult to reduce the viscosity to the target viscosity by only one kneading operation. For this reason, it is necessary to cool the rubber material once kneaded and take it out, and then add it again to repeat the kneading operation a plurality of times, resulting in poor productivity.

  In addition, since components such as alcohol generated by the coupling reaction are unlikely to diverge outside the hermetic kneader, it takes a long time to complete the reaction by suppressing the coupling reaction. There was a problem of becoming.

Various other kneading methods for rubber materials have been proposed in which productivity is improved by pre-kneading with a closed-type kneader and then kneading with an open-structure roll kneader (for example, patents). Reference 1). According to this method, by mixing the silica compounded rubber material with a roll kneader having an open structure, the generated components such as alcohol are emitted to the outside, so that it is possible to prevent the coupling reaction from being suppressed by the reaction generated components. . However, since the rubber material is exposed to the outside air, the temperature of the rubber tends to decrease during kneading, making it difficult to provide a sufficient amount of heat to complete the coupling reaction, and the silica is well dispersed to stabilize the quality. There was a problem that it would be difficult to achieve this.
JP-A-5-305612

  An object of the present invention is to provide a kneading system for a silica-containing rubber material excellent in productivity, capable of improving the dispersibility of silica to stabilize quality and obtaining a rubber having a target viscosity in a short time. It is in.

  In order to achieve the above object, the kneading system for silica compounded rubber material of the present invention comprises a single closed kneader for kneading raw rubber and a non-vulcanized compounding agent containing silica and a silane coupling agent, At least one row in which one reaction promoting kneader for kneading the primary kneaded rubber discharged from the mold kneader and at least one kneader for kneading the secondary kneaded rubber discharged from the reaction promoting kneader are arranged. A kneading line and a final kneading machine for kneading the tertiary kneaded rubber discharged from the kneading line and the vulcanizing compound are arranged in order so as to be connected by a conveying means, and the reaction kneader and The kneading machine disposed in the kneading line is configured as an open structure roll kneading machine including a pair of kneading rolls and a conveyor that forms a circulation path from a lower position of the pair of kneading rolls to an upper position again. And the reaction kneader and is characterized in that a heating means for heating the primary kneading rubber is kneaded.

  According to the kneading system of the silica-blended rubber material of the present invention, the primary kneaded rubber kneaded by the closed kneader is kneaded by the reaction promoting kneader having an open structure, whereby the coupling reaction between the silica and the coupling agent. Since it can knead | mix, disperse | distributing generation | occurrence | production components, such as alcohol produced | generated by the outside, it can prevent that coupling reaction is suppressed by these generation | occurrence | production components.

  In the reaction promoting kneader, the coupling reaction can be promoted by kneading the rubber material exposed to the outside air while applying a necessary amount of heat with a heating means.

  By performing the kneading as described above, the coupling reaction can be completed in a short time, and silica can be quickly and well dispersed in the rubber material to stabilize the quality.

  In addition, after kneading by the reaction promoting kneader, the secondary kneaded rubber is lowered to the target viscosity by the kneading line in which another open-structure roll kneader on the downstream side is arranged to obtain the tertiary kneaded rubber, The steps until obtaining the final kneaded rubber can be continuously performed by the final kneader, and one batch of kneaded rubber having the target viscosity can be obtained in a short time.

  In addition, while kneading a batch of rubber material, the kneading machine on the upstream side can start kneading of another batch of rubber material. Obtainable.

  Hereinafter, the kneading system for silica-containing rubber material of the present invention will be described based on the embodiments shown in the drawings. As illustrated in FIG. 1, in the kneading system of the embodiment, one reaction promoting kneading machine 5, four rows of kneading lines 16, and one final kneading line are sequentially arranged downstream of one closed kneader 1. A machine 19 is arranged.

  The closed kneader 1 and the reaction promoting kneader 5 are arranged so as to be connected by the transport conveyor 3 and the weighing conveyor 4. The reaction promoting kneader 5 and the kneading line 16 are connected by a sorting conveyor 15, and the kneading line 16 and the final kneading machine 19 are arranged to be connected by a transport conveyor 20.

  The reaction accelerating kneader 5 is a roll kneader having an open structure as illustrated in FIG. 2, and reaches one side of a pair of opposing kneading rolls 6, 6 from a lower position of the kneading rolls 6, 6 to an upper position. The transfer conveyor 13 and the kneading conveyor 14 are arranged so as to form a circulation path. The pair of kneading rolls 6 and 6 are rotated by hydraulic or electric drive motors 8 and 8 in opposite directions, and one kneading roll 6 is moved by an actuator 9 so that the roll gap can be changed. A roll gap sensor 11 is disposed below the kneading roll 6, and a temperature sensor 10 that detects the rubber temperature is disposed above the transfer conveyor 13 and the kneading conveyor 14. Moreover, the heater 7 is installed in the delivery conveyor 13 and the kneading conveyor 14.

  The power level P (drive torque), roll surface speed, roll gap, and rubber temperature data of the drive motors 8 and 8 are configured to be transmitted to the control device 12.

  In each kneading line 16, a roll kneader 17 having an open structure as illustrated in FIG. 3 is arranged. The roll kneader 17 has substantially the same structure as the reaction promoting kneader 5 illustrated in FIG. 2, but includes a cooling fan 18 instead of the heater 7 and is provided above the transfer conveyor 13. In FIG. 3, the same reference numerals as in FIG. 2 are used for the same components as in FIG.

  Further, when the length of the circulation path formed by the delivery conveyor 13 and the kneading conveyor 14 is compared with the reaction promoting kneader 5, the reaction promoting kneader 5 is set shorter, and the reaction promoting kneader 5 It is configured such that the temperature of the rubber material is less likely to decrease during kneading.

  The final kneader 19 is also an open structure roll kneader having the same basic structure as that shown in FIG. 3, and is further connected with a vulcanizing compounding agent charging device 21.

  Hereafter, the kneading | mixing process of the silica compounding rubber material by this kneading system is demonstrated. The rubber material discharged from the closed kneading machine 1 is the primary kneading rubber R1, the rubber material discharged from the reaction promoting kneading machine 5 is the secondary kneading rubber R2, and the rubber material discharged from the kneading line 16 is the tertiary kneading rubber. The rubber material discharged from R3 and the final kneader 19 will be described as the final kneaded rubber RF.

  In order to complete the coupling reaction of the silica compounded rubber material, it is necessary to apply a predetermined amount of heat, which is defined as the amount of heat history obtained by multiplying the amount of heat applied and the time of application of the amount of heat. By doing so, it is grasped and decided.

  Further, the target heat history amount to be applied by the reaction promoting kneader 5 obtained by subtracting the heat history amount to be applied by the closed kneader 1 from the heat history amount necessary for the completion of the coupling reaction is set in advance and controlled. The data is input to the device 12.

  In the closed kneading machine 1, the raw rubber and the non-vulcanizing compounding agent containing silica and the silane coupling agent are preliminarily kneaded, and an intermediate heat quantity necessary for completing the coupling reaction is given. . The temperature of the primary kneading rubber R1 when discharged from the closed kneading machine 1 is, for example, about 150 ° C.

  Next, the primary kneading rubber R <b> 1 is formed into a sheet shape by the sheeting roll 2, and is conveyed to the reaction promoting kneader 5 by the conveying conveyor 3 and the weighing conveyor 4. In the weighing conveyor 4, the weight of the primary kneaded rubber R <b> 1 is weighed, and an amount of the vulcanizing compound compounding agent Q corresponding to the weighed weight is charged by a vulcanizing compound compounding device 21 described later. As long as the primary kneaded rubber R1 can be weighed, other weighing means may be used instead of the weighing conveyor 4.

  In the reaction promoting kneader 5, the primary kneading rubber R 1 is repeatedly supplied to the kneading rolls 6, 6 by the delivery conveyor 13 and the kneading conveyor 14, and shearing force is applied by passing between the kneading rolls 6, 6. Kneading is performed.

  Here, the primary kneaded rubber R1 circulates in a sheet-like state with a wide surface area, so that reaction-suppressing components such as alcohol generated by the coupling reaction can be efficiently diffused to the outside, and the coupling reaction Can be suppressed.

  Further, the primary kneaded rubber R1 is heated by the heater 7 during kneading while being exposed to the outside air, so that the amount of applied heat can be increased and the coupling reaction is promoted. Therefore, kneading can be performed while applying the remaining amount of heat in a short time so as to achieve the target heat history amount, and silica can be quickly and well dispersed in the rubber material.

  The heater 7 may be any heater that can heat the primary kneaded rubber R1 to a necessary temperature, and various heating means can be used.

  Based on the rubber temperature data detected by the temperature sensor 10 and the kneading time, the control device 12 sequentially calculates the amount of heat history applied by the reaction promoting kneader 5, and the calculated amount of heat history and the target amount of heat history. And the kneading operation in the reaction promoting kneader 5 is controlled so that the former and the latter match.

  In order to apply the amount of heat so as to reach the target heat history amount at a predetermined time, the control device 12 performs heating temperature of the heater 7, surface speed of the kneading rolls 6 and 6, conveyance speed of both conveyors 13 and 14, roll gap Control at least one of the following. By controlling and kneading in this manner, the coupling reaction can be promoted and completed with high accuracy, the silica can be dispersed well, and the quality can be stabilized. For example, kneading is performed at a roll gap of 3 to 15 mm and a rubber temperature of 90 to 160 ° C.

  Next, the secondary kneaded rubber R2 imparted with the necessary amount of heat to the primary kneaded rubber R1 is rotated in the middle of the delivery conveyor 13 so as to be connected to the sorting conveyor 15, and is transferred to the sorting conveyor 15.

  The distribution conveyor 15 has a number of distribution movable parts 15a corresponding to the number of kneading lines 16, and each distribution movable part 15a is movable so as to open and close the gaps. The secondary kneading rubber R2 passes through the gap in which the sorting movable portion 15a corresponding to the selected kneading line 16 is opened, and is conveyed to the selected one kneading line 16. The means for selectively distributing the secondary kneading rubber R2 to one kneading line 16 is not limited to the above, and other configurations can be used.

  In the kneading line 16 where the secondary kneaded rubber R2 is conveyed, the roll kneader 17 kneads the secondary kneaded rubber R2 so as to reach the target viscosity in a predetermined time. In the kneading line 16, the main purpose is to lower the viscosity, so that the kneading is performed at a lower temperature than the reaction promoting kneader 5. At that time, at least one of the operation of the cooling fan 18, the surface speed of the kneading rolls 6 and 6, the transport speed of both the conveyors 13 and 14, and the roll gap is controlled. For example, kneading is performed at a roll gap of 1 to 10 mm and a rubber temperature of 40 to 100 ° C.

  The kneading line 16 is not limited to four rows, and may be one row or other plural rows. By providing a plurality of kneading lines 16, one batch of secondary kneading rubber R <b> 2 that is being conveyed one after another can be successively conveyed to an empty kneading line 16 for kneading, further improving productivity. Can be improved.

  The kneading line 16 may be configured by arranging a plurality of roll kneaders 17 in series. In the case of the secondary kneading rubber R2 in which the viscosity is not easily lowered, the kneading time in one roll kneading machine 17 is shortened by sequentially kneading with a plurality of directly connected roll kneading machines 17, so that 1 in a short time cycle. Batch kneading can be performed, and productivity can be increased.

  The tertiary kneaded rubber R3 having the target viscosity by kneading the secondary kneaded rubber R2 is discharged from the kneading line 16 by the delivery conveyor 13 and conveyed to the final kneader 19 by the conveyor 20. Here, a vulcanizing compound additive Q such as sulfur or a vulcanization accelerator is charged by the vulcanizing compound adding device 21 and kneaded together with the tertiary kneading rubber R3. Since the vulcanizing compounding agent Q is scattered in powder form, it is charged in a state of being mixed in advance with a separately prepared rubber material.

  After the final kneading is completed, the final kneaded rubber RF discharged from the final kneading machine 19 is conveyed to the sheeting roll 23 by the conveying conveyor 22, where it becomes a sheet-like rubber and is conveyed in the middle of the sampling device 24. It is conveyed to the cooling device 26 by the conveyor 25 and stored in a predetermined place until it is used in the next process.

  As described above, in the kneading system of the present invention, the heat necessary for the completion of the coupling reaction is imparted to one batch of silica-blended rubber material, kneading is performed, and the final kneading step for kneading the vulcanizing compound Q is performed. The final kneaded rubber RF having the target viscosity can be obtained in a short time by performing continuously.

  In addition, while one batch of rubber material is being kneaded, a new batch of rubber material can be kneaded in the upstream process. Therefore, the final kneaded rubber RF can be obtained with high productivity by kneading a new batch of rubber material sequentially in a constant time cycle.

  As shown in FIG. 4, the vulcanizing compounding agent charging device 21 can be arranged so as to be connected to the sorting conveyor 15. In FIG. 4, the upstream side of the sorting conveyor 15 is the same as that in FIG. In this arrangement, the vulcanizing compounding agent Q is introduced into the kneading line 16, and the vulcanizing compounding agent Q is preliminarily applied to the secondary kneading rubber R2 that has approached the target viscosity or the tertiary kneading rubber R3 that has reached the target viscosity. Knead. This preliminary kneading is performed at a temperature at which the vulcanization reaction does not proceed.

  Thus, the kneading time in the final kneader 19 can be reduced by preliminarily kneading the vulcanized compounding agent Q before the rubber temperature is lowered while being conveyed from the kneading line 16 to the final kneader 19. The final kneaded rubber RF having the target viscosity can be obtained in a shorter time.

1 is an overall configuration diagram illustrating a kneading system of the present invention. It is a side view which illustrates the reaction promotion kneader of FIG. It is a side view which illustrates the roll kneader which comprises the kneading line of FIG. It is a partial block diagram which shows the modification of the kneading | mixing system of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sealing type mixer 2 Sheeting roll 3 Conveyor 4 Measurement conveyor 5 Reaction promotion kneading machine 6 Kneading roll 7 Heater 8 Drive motor 9 Actuator 10 Temperature sensor 11 Roll gap sensor 12 Control device 13 Delivery conveyor 14 Repeating conveyor 15 Sorting conveyor 15a Sorting movable part 16 Kneading line 17 Roll kneading machine 18 Cooling fan 19 Final kneading machine 20 Conveying conveyor 21 Vulcanization system compounding device 22 Conveying conveyor 23 Seating roll 24 Sampling device 25 Conveying device 26 Cooling device R1 Primary kneading rubber R2 Secondary Kneaded rubber
R3 Tertiary kneaded rubber RF Final kneaded rubber Q Vulcanizing compound

Claims (6)

  One closed-type kneader for kneading raw rubber and a non-vulcanizing compound containing silica and a silane coupling agent, and one reaction promotion for kneading the primary kneaded rubber discharged from the closed-type kneader A kneading machine, at least one kneading line in which at least one kneading machine for kneading the secondary kneaded rubber discharged from the reaction accelerating kneading machine, and a tertiary kneaded rubber discharged from the kneading line and vulcanized One final kneader for kneading the system compounding agent is disposed in order so as to be connected by a conveying means, and the kneader disposed in the reaction kneader and the kneading line is provided with a pair of kneading rolls and the pair The roll kneader having an open structure provided with a conveyor that forms a circulation path from the lower position of the kneading roll to the upper position again, and the kneaded primary kneaded rubber is heated in the reaction kneader. Heating means Kneading system of the silica compounded rubber material provided.   The predetermined amount of heat history required for completing the coupling reaction of the silica and the silane coupling agent is set to be given by the closed kneader and the reaction accelerating kneader, and the set reaction accelerating kneader The amount of heat history applied by the reaction promoting kneading machine is compared with the amount of heat history applied by the reaction accelerating kneader, and the reaction is performed based on the comparison result so that the target heat history amount is applied at a preset time. The kneading system for a silica-blended rubber material according to claim 1, further comprising a control device for controlling a kneading operation of the accelerating kneader.   The reaction promoting kneader is provided with a temperature sensor for detecting the temperature of the primary kneaded rubber being kneaded, and configured to transmit a detection signal of the temperature sensor to the control device. The kneading system for a silica-containing rubber material according to claim 2, wherein the heat history amount applied by the reaction promoting kneader is calculated based on the kneading time at the temperature.   The control device performs kneading by controlling at least one of a heating temperature by the heating means of the reaction promoting kneader, a roll surface speed of the kneading roll and a conveyor conveyance speed, and a roll gap of the kneading roll. The kneading system for a silica-containing rubber material according to claim 2 or 3, wherein the system is a kneading system.   5. The apparatus according to claim 1, wherein a plurality of rows of the kneading lines are provided, and a distribution unit that distributes the secondary kneaded rubber discharged from the reaction promoting kneader to any one of the kneading lines is provided. A kneading system for silica-containing rubber material described in 1.   A configuration in which the vulcanized compounding agent is set to be introduced into the kneading line, and a tertiary kneaded rubber prepared by preliminarily kneading the vulcanized compounding agent and the secondary kneaded rubber is conveyed to the final kneader. Item 6. A kneading system for a silica-containing rubber material according to any one of Items 1 to 5.

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