JP7293996B2 - Synthetic rubber manufacturing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing synthetic rubber, and more particularly to a method for producing synthetic rubber suitable for producing acrylic rubber sheets and veils.

Synthetic rubber, such as acrylic rubber, is a polymer whose main component is acrylic acid ester, and is generally known as a rubber with excellent heat resistance, oil resistance, and ozone resistance, and is widely used in automobile-related fields. .

Such synthetic rubbers are usually prepared by emulsion polymerization of monomer components constituting the rubber, bringing the obtained emulsion polymerization solution into contact with a coagulant, drying the resulting water-containing crumbs to a predetermined water content or less, and then baling them. It is shipped as a product in a state of being made.

As a conventional method for producing this kind of synthetic rubber, for example, in Patent Document 1, in order to cut a cut sheet-shaped rubber of a predetermined length from a continuous adhesive sheet, cutting is performed above and below a predetermined conveying position of a roller conveyor. It is disclosed that a rubber sheet is cut by providing a blade and a blade receiver and sandwiching the rubber sheet between the cutting blade and the blade receiver.

Further, in Patent Document 2, among a plurality of conveyors that convey sheet-like unvulcanized rubber continuously supplied from an unvulcanized rubber supply device, a cutter is arranged at the upper end of the conveyor on the upstream side, A movement distance sensor for measuring the movement distance of the rubber sheet is arranged at the upstream end of the conveyor, and a rubber bale of a specified weight range is cut out for each predetermined movement distance of the continuously supplied rubber sheet. there is

JP-A-3-117595 JP-A-6-201440

However, in the conventional synthetic rubber manufacturing method as described above, since the cutting blade has a wide range of portions where the cutting edge line is parallel to the upper surface of the rubber sheet, the cutting force is reduced during the descent of the cutting blade. is greatly changed, the rubber sheet is bent, and there is a possibility that the cut surface is tilted or twisted or the rubber sheet is misaligned.

Therefore, the present invention realizes a method for manufacturing synthetic rubber that can obtain a good cut surface by regulating the tilting of the blade in the conveying direction and effectively suppressing the tilting and twisting of the rubber sheet during cutting. intended to

In order to achieve the above object, the synthetic rubber manufacturing method of the present invention comprises a conveying step of conveying a sheet-like synthetic rubber continuous with a predetermined width by a conveyor, and a cutting step of cutting the leading end portion of the synthetic rubber into a cut sheet of a predetermined length, wherein the cutting step faces the upper surface of the sheet-like synthetic rubber on the conveyor A cutting blade having a blade portion whose cutting edge line is continuously changed to different heights is arranged with respect to the upper surface of the sheet-shaped synthetic rubber, and the cutting blade is placed on the sheet-shaped synthetic rubber on the conveyor. It is characterized in that the sheet-like synthetic rubber is cut at a predetermined conveying position by moving the cutting blade up and down while guiding it so that it can be raised and lowered from the outer side.

With this configuration, in the present invention, a continuous sheet of synthetic rubber having a predetermined width is cut in the conveying direction by a cutting blade having a different cutting edge line height depending on the position of the sheet of synthetic rubber in the width direction. Since cutting progresses continuously in the entire width direction of the tip portion, it is possible to uniformly cut to a predetermined length and to cut into a good cut surface shape. In addition, since the cutting blade is guided up and down outside the sheet-shaped synthetic rubber, it is possible to stably cut by restricting the tipping of the blade in the conveying direction, and the sheet-shaped synthetic rubber is laterally displaced by the guide means. can be easily restricted.

In the method for producing a synthetic rubber of the present invention, in the cutting step, the sheet-like synthetic rubber is placed adjacent to each other in the width direction so as to face the upper surface of the sheet-like synthetic rubber on the conveyor. A cutting blade having a plurality of protruding blade portions protruding toward the synthetic rubber in a shape is arranged, and the protruding blade portions of the cutting blade are raised and lowered to cut the sheet-shaped synthetic rubber at a plurality of locations in the width direction. may be cut in parallel. The protruding cutting edge preferably has an edge line bent at an obtuse angle or an acute angle, and more preferably bent at an obtuse angle.

In this case, the continuous sheet-shaped synthetic rubber of a predetermined width is cut at multiple points throughout the width direction by a plurality of protruding blades adjacent to the width direction of the sheet-shaped synthetic rubber. It can be cut to a predetermined length evenly and can be cut into a good cut surface shape.

In the synthetic rubber manufacturing method of the present invention, the sheet is cut in the cutting step by a cutting blade having a plurality of vertical guide portions projecting downward from the cutting edge line on the outer side of the sheet-shaped synthetic rubber on the conveyor. The cutting blade may be vertically guided by the plurality of vertical guides while the cutting blade is being moved up and down.

In this way, the cutting blade during cutting can be vertically guided on both sides in the width direction of the sheet-shaped synthetic rubber, so that the cutting blade can be stably tilted or twisted in the conveying direction regardless of the vertical movement position. can be suppressed, and cutting workability can be improved.

In the synthetic rubber manufacturing method of the present invention, in the cutting step, the distance between the tips of the plurality of protruding blade portions adjacent to each other in the width direction of the sheet-like synthetic rubber is set to the thickness of the sheet-like synthetic rubber. It can also be set to 1 to 3 times the height. In this way, since the sheet-like synthetic rubber is cut at multiple points by descending the plurality of protruding blades, it is possible to effectively suppress lateral displacement of the cut portion and vertical displacement of the surface (displacement in the conveying direction). It can be cut into a good cut surface shape.

In the method for producing synthetic rubber of the present invention, in the cutting step, a cutting blade having a triangular wave tip height smaller than the thickness of the synthetic rubber sheet may be used. can. In this case, when the sheet-shaped synthetic rubber is cut at multiple points by descending the plurality of protruding blades, the entire cutting edge is brought close to the upper surface of the synthetic rubber before proceeding with the multi-point cutting. Lateral slippage and vertical slippage of the surface can be effectively suppressed, and the cut surface can be cut into a good shape.

In the method for producing synthetic rubber of the present invention, in the cutting step, a cutting blade composed of a cutting edge portion having an acute cutting edge angle forming surface and a plate portion having substantially parallel front and back surfaces is used. good too. In this case, while suppressing the deformation of the cut surface in the conveying direction, the cut sheet-like synthetic rubber can be separated from the following sheet portion at a certain distance when the cutting is completed, and it is possible to effectively prevent cutting defects due to adhesion etc. In addition, each transfer control after separation can be executed independently.

In the synthetic rubber manufacturing method of the present invention, the synthetic rubber is preferably an acrylic rubber, particularly an acrylic rubber having a reactive group. It is possible to efficiently produce synthetic rubber suitable for various rubber products that require oil resistance at high temperatures.

According to the present invention, it is possible to realize a method for manufacturing synthetic rubber that is capable of regulating the tilting of the blade in the conveying direction, effectively suppressing the tilting and twisting of the rubber sheet during cutting, and obtaining a good cut surface. can do.

It is a figure which shows the conveyance type cooling device and cutting device in the synthetic rubber manufacturing system which concerns on one Embodiment of this invention. (a) is a view of the cutting device of the embodiment shown in FIG. 1 as seen from the dry rubber conveying direction, and (b) is a cross-sectional view of the cutting device. (a) is a partially enlarged view of the cutting device of FIG. 2, and (b) is an enlarged side cross-sectional view of a main part of a cutting blade. BRIEF DESCRIPTION OF THE DRAWINGS It is a flowchart which shows the outline|summary procedure of the synthetic-rubber manufacturing method which concerns on one Embodiment of this invention.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First, a synthetic rubber manufacturing system according to an embodiment of the present invention that can be used for manufacturing synthetic rubber will be described.

The synthetic rubber manufacturing system according to the present embodiment can be used, for example, for manufacturing acrylic rubber. In the following, acrylic rubber will be described as an example, but it can also be used for manufacturing synthetic rubbers other than acrylic rubber. can be done.

Other synthetic rubbers include, for example, styrene-butadiene rubber (SBR), butadiene rubber (BR), isoprene rubber (IR), styrene-isoprene block polymer (SIS), styrene-butadiene block polymer (SBS), nitrile butadiene rubber. (NBR), chloroprene rubber (CR), butyl rubber (IIR), ethylene-propylene-diene terpolymer rubber (EPDM), chlorosulfonated polyethylene rubber, olefinic rubber such as fluororubber, silicone rubber, urethane rubber and the like.

The synthetic rubber production system according to this embodiment includes an emulsion polymerization device, a coagulation device, a washing device, a screw-type extrusion dryer 5, a conveying cooling device 6, a cutting device 7, and a bale forming device. Further, as will be described later in detail, the synthetic rubber manufacturing method according to the embodiment of the present invention includes an emulsion polymerization process, a coagulation process, a washing process, an extrusion drying process, a transport cooling process, a cutting process, and a bale process. contains. Each of the devices used in these steps will be described below.

[Emulsion polymerization device]
An emulsion polymerization apparatus (not shown) is an apparatus used for processing related to the emulsion polymerization step in the synthetic rubber manufacturing method according to the present embodiment. Specifically, in the emulsion polymerization apparatus, a monomer component for forming a synthetic rubber such as acrylic rubber is mixed with water and an emulsifier in a reactor, and the mixture is emulsified while being appropriately stirred with a stirrer, and polymerized. An emulsion polymerization liquid is obtained by performing emulsion polymerization in the presence of a catalyst. The reactor of the emulsion polymerization apparatus according to the present embodiment is a continuous type in which the charging of raw materials into the reactor, the reaction, and the recovery of the product are all performed at the same time. good. Further, the reactor of the emulsion polymerization apparatus according to the present embodiment is a tank reactor, but may be a tubular reactor.

[Coagulation device]
The coagulating device is a device used for processing related to the coagulating step in the synthetic rubber manufacturing method according to the present embodiment. Specifically, the coagulation device is adapted to bring the emulsion polymerization liquid obtained in the emulsion polymerization device into contact with a coagulation liquid as a coagulant to coagulate the water-containing crumbs. The coagulation device according to the present embodiment includes a coagulation tank for containing the emulsion polymerization liquid and the coagulation liquid obtained in the emulsion polymerization apparatus, a heating device for heating the inside of the coagulation tank and maintaining a desired temperature, and a It is equipped with a stirring device for stirring the emulsion polymerization liquid and the coagulation liquid.

The coagulation tank is composed of, for example, a closed bottom and a cylindrical side wall, and is capable of storing the emulsion polymerization liquid and the coagulation liquid. The heating device includes a heating section for heating the inside of the coagulation tank, and a temperature control section for controlling the temperature inside the coagulation tank. The stirring device has a stirring blade, which is a member that is arranged in the coagulation tank and rotates around a predetermined axis, a motor that rotates the stirring blade, and a drive control section that controls the rotation speed and rotation speed of the stirring blade. .

In the coagulation device of the present embodiment, the emulsion polymerization liquid and the coagulation liquid are brought into contact with each other by adding the emulsion polymerization liquid to the coagulation liquid being stirred. That is, a coagulation tank of a coagulation device is filled with a coagulation liquid, and an emulsion polymerization liquid is added to and brought into contact with the coagulation liquid to coagulate the emulsion polymerization liquid, thereby producing water-containing crumbs.

The heating device of the coagulation device is configured to heat the coagulation liquid filled in the coagulation tank. Specifically, the heating device sends steam to a jacket as a heating section provided on the outer periphery of the coagulation tank, and heats the coagulation liquid by exchanging heat between the steam and the coagulation tank or the coagulation liquid in the coagulation tank. It's like

The temperature control unit of the coagulation device is configured to control the temperature in the coagulation tank by controlling the heating operation of the heating unit while monitoring the temperature in the coagulation tank measured by a thermometer. The temperature of the coagulation liquid in the coagulation tank is controlled by the temperature control section to be generally 40°C or higher, preferably 40 to 90°C, more preferably 50 to 80°C.

In order to control the temperature of the liquid phase in the coagulation tank to a set temperature, for example, one control system controls the temperature and flow rate of steam that heats the coagulation tank, and the temperature of hot water supplied to the coagulation tank is controlled. A liquid phase temperature control system of a cascade control method may be configured in which the other control system is used together.

The stirring device of the coagulation device is configured to stir the coagulation liquid filled in the coagulation tank. Specifically, the stirring device includes a motor that generates rotational power and stirring blades that extend in a direction perpendicular to the rotating shaft of the motor. The stirring impeller is designed to flow the coagulated liquid by rotating around a rotating shaft by the rotational power of the motor in the coagulated liquid filled in the coagulation tank. The shape, size, and number of stirring blades to be installed are appropriately determined in consideration of the required strength of stirring.

The drive control unit of the coagulation device is configured to control the rotational drive of the motor of the stirring device to set the number of revolutions and the rotational speed of the stirring blades of the stirring device to predetermined values. The rotation of the stirring blades is controlled by the drive control unit so that the stirring speed of the coagulated liquid is usually 100 rpm or more, preferably 200 to 1000 rpm, more preferably 300 to 900 rpm, and particularly preferably 400 to 800 rpm. be. The peripheral speed of the coagulation liquid is usually 0.5 m/s or higher, preferably 1 m/s or higher, more preferably 1.5 m/s or higher, particularly preferably 2 m/s or higher, and most preferably 2.5 m/s or higher. Rotation of the stirring blades is controlled by the drive control unit so that Furthermore, the driving control unit stirs so that the upper limit of the peripheral speed of the coagulation liquid is usually 50 m/s or less, preferably 30 m/s or less, more preferably 25 m/s or less, and most preferably 20 m/s or less. Wing rotation is controlled.

The coagulation device overflows the produced water-containing crumbs together with hot water from the coagulation tank to take them out of the coagulation tank, and supplies them to the cleaning device that performs the cleaning process. Between the coagulation device and the washing device is arranged a drainer capable of separating free water from the wet crumbs, through which the wet crumbs are fed to the washing device. . The water separated by the drainer is collected in the tank. The water stored in the tank is pumped to the coagulation tank and reused.

[Washing equipment]
The cleaning device is a device used for processing related to the cleaning step in the synthetic rubber manufacturing method according to the present embodiment. Specifically, the washing device is adapted to wash the wet crumbs generated in the coagulation device with washing water. The cleaning apparatus according to the present embodiment includes a cleaning tank containing wet crumbs produced in a coagulation apparatus and cleaning water, a heating device for heating the inside of the cleaning tank and maintaining a desired temperature, and a It is equipped with an agitator for agitating the wet crumbs and the washing water.

The washing tank is composed of, for example, a closed bottom and a cylindrical side wall, so that the wet crumbs and washing water can be stored. The heating device includes a heating section that heats the inside of the cleaning tank, and a temperature control section that controls the temperature inside the cleaning tank. The stirring device has a stirring blade, which is a member that is arranged in the washing tank and rotates around a predetermined axis, a motor that rotates the stirring blade, and a drive control section that controls the rotation speed and rotation speed of the stirring blade. . In the washing device, the water-containing crumbs produced in the coagulating device are mixed with a large amount of water and washed, thereby effectively reducing the amount of ash in the finally obtained synthetic rubber sheet or synthetic rubber veil.

The heating device of the cleaning device is configured to heat the inside of the cleaning tank. Further, the temperature control unit of the cleaning apparatus is configured to control the temperature in the cleaning tank by controlling the heating operation of the heating unit while monitoring the temperature in the cleaning tank measured by the thermometer. . As described above, the temperature of the washing water in the washing tank is usually controlled to be 40°C or higher, preferably 40 to 100°C, more preferably 50 to 90°C, and most preferably 60 to 80°C. .

The washing apparatus causes the washed wet crumbs to overflow from the washing tank together with the washing water, takes them out of the washing tank, and supplies them to the screw-type extrusion dryer 5 that performs the dehydration process and the drying process. A drainer capable of separating free water from the washed wet crumbs is arranged between the washing device and the screw-type extrusion dryer 5, and the water-containing crumbs pass through the drainer and are subjected to screw-type extrusion drying. It is designed to be supplied to the machine 5. Although a screen is used for the drainer of this embodiment, a wire mesh, an electric sieve, etc., for example, can also be used. Free water separated by the drainer is collected in the tank. The water stored in the tank is pumped to the coagulation tank and reused.

When the washed wet crumbs are supplied to the screw-type extrusion dryer 5, the temperature of the wet crumbs is preferably 40°C or higher, more preferably 60°C or higher. For example, by setting the temperature of water used for washing in the washing device to 40° C. or higher, preferably 60° C. or higher (for example, 70° C.), the temperature of the water-containing crumbs when supplied to the screw-type extruder dryer 5 is reduced to 40° C. C. or higher, preferably 60.degree. It may be warmed. As a result, dehydration in the subsequent dehydration step and drying in the drying step can be effectively performed, and the moisture content of the finally obtained dry rubber can be significantly reduced.

[Screw type extrusion dryer]
The screw-type extrusion dryer 5 is a device used for processing related to the extrusion drying process (dehydration process and drying process) in the synthetic rubber manufacturing method according to the present embodiment. Specifically, the screw-type extrusion dryer 5 dehydrates the wet crumbs washed by the washing device using a dewatering slit, and dries the dehydrated wet crumbs to obtain dry rubber having a predetermined water content or less. ing. Further, the screw-type extrusion dryer 5 is configured to mold the dried rubber obtained by the dehydration process and the drying process into a predetermined shape and discharge it.

Specifically, the screw-type extrusion dryer 5 includes a dehydrating barrel functioning as a dehydrator for dehydrating the wet crumbs washed by the washing device, and a drying barrel functioning as a dryer for drying the wet crumbs. and a die section 11 having a forming function of forming a wet crumb on the downstream side of the screw-type extrusion dryer 5 .

Although the screw-type extrusion dryer 5 is used in the present embodiment, a centrifugal separator, a squeezer, or the like may be used as the dehydrator for performing the dehydration process. A hot air drier, a reduced pressure drier, an expander drier, a kneader type drier, or the like may be used as the dryer. Below, a screw type extrusion dryer may be called an extrusion dryer.

The screw-type extrusion dryer 5 according to this embodiment is a twin-screw-type screw-type extrusion dryer having a pair of screws in a barrel unit. The screw-type extrusion dryer 5 has a drive unit that rotates a pair of screws in the barrel unit. A drive unit is attached to the upstream end of the barrel unit. Further, the screw-type extrusion dryer 5 has a die section 11 at the downstream end of the barrel unit.

The barrel unit has a supply barrel section, a dewatering barrel section, and a drying barrel section from the upstream side to the downstream side.

Here, an example of operating conditions of the screw-type extruder dryer 5 according to this embodiment will be given.

The rotation speed (N) of the pair of screws in the barrel unit may be appropriately selected according to various conditions, and is usually 10 to 1000 rpm, from the viewpoint of efficiently reducing the water content and gel amount of the acrylic rubber. , preferably 50-750 rpm, more preferably 100-500 rpm, most preferably 120-300 rpm.

The extrusion rate (Q) of the acrylic rubber is not particularly limited, but is usually 100 to 1500 kg/hr, preferably 300 to 1200 kg/hr, more preferably 400 to 1000 kg/hr, and more preferably 500 to 800 kg/hr. Most preferred.

The ratio (Q/N) between the extrusion rate (Q) of the acrylic rubber and the number of revolutions (N) of the screw is not particularly limited, but is usually 1 to 20, preferably 2 to 10, more preferably 3 to 8, with 4 to 6 being particularly preferred.

[Conveyor type cooling device]
The transport-type cooling device 6 is a device used for processing related to the transport cooling step in the synthetic rubber manufacturing method according to the present embodiment. Specifically, the conveying cooling device 6 is a device used for cooling the dried rubber obtained by the screw-type extrusion dryer 5 . As shown in FIG. 1, the conveying type cooling device 6 according to the present embodiment conveys the sheet-like synthetic rubber 15 extruded from the die part 11 of the screw-type extrusion dryer 5 by the conveyer 61, and cools the cooling means. By blowing cooling air from 65, it cools down to a predetermined cooling temperature. The conveying type cooling device 6 has a configuration in which a conveyer 61 for conveying the sheet-like synthetic rubber 15 and a cooling means 65 for sending cooling air are arranged in a cooling tank 66 .

More specifically, the conveyor 61 conveys the sheet-like synthetic rubber 15 discharged from the die part 11 of the screw-type extrusion dryer 5 in the direction of arrow A in FIG. The conveyor 61 has rollers 62 and 63 and a conveyor belt 64 wound around the rollers 62 and 63 and on which the sheet-like synthetic rubber 15 is placed. The conveyor 61 is configured to continuously convey the sheet-like synthetic rubber 15 discharged from the die portion 11 of the screw-type extrusion dryer 5 onto the conveyor belt 64 to the downstream side.

The cooling means 65 blows cooling air sent from a cooling air generating means (not shown) onto the surface of the sheet-like synthetic rubber 15 on the uppermost conveyor 61 .

The length of the conveyor 61 and the cooling means 65 of the transport-type cooling device 6 (the length of the portion to which the cooling air can be blown) is not particularly limited, but is, for example, 2 to 100 m, preferably 5 to 50 m. In addition, the conveying speed of the sheet-shaped synthetic rubber 15 in the conveying type cooling device 6 is determined by the length of the conveyor 61 and the cooling means 65, It may be appropriately adjusted according to the discharge rate, target cooling rate, cooling time, etc., and is, for example, 10 to 100 m/hr, more preferably 15 to 70 m/hr.

The transport-type cooling device 6 is not particularly limited to a configuration including two conveyors 61, 61 and one cooling means 65 as shown in FIG. It may be configured to have one or three or more corresponding cooling means 65 . In that case, the total length of each of one or more of the conveyors 61 and the cooling means 65 should be within the above range.

The conveying cooling device 6 shown in FIG. 1 is directly connected to the die section 11 of the screw-type extrusion dryer 5 or installed in the vicinity of the die section 11 for use.

The transport-type cooling device 6 according to the present embodiment is an air-cooling system, but is not limited to this, and various systems including a water-spraying system in which water is sprayed, an immersion system in which water is immersed, and the like can be adopted. be. Alternatively, the dried rubber may be cooled by leaving it at room temperature.

[Cutting device]
The cutting device 7 is configured to perform processing related to the cutting step in the synthetic rubber manufacturing method according to the present embodiment. Specifically, the cutting device 7 is a device used for cutting the sheet-shaped synthetic rubber 15 after cooling.

As shown in FIG. 1, the cutting device 7 according to the present embodiment cuts the front end portion of the sheet-like synthetic rubber 15 cooled to a predetermined cooling temperature by the conveying type cooling device 6 into a pair of adjacent roller conveyors 74 . The synthetic rubber 16 is cut at a predetermined conveying position between the rollers 75 and 75 to obtain a cut sheet-like synthetic rubber 16 of a predetermined length.

With this configuration, the front end portion of the sheet-shaped synthetic rubber 15 (dry rubber) cooled to a predetermined cooling temperature is cut into cut sheets between the adjacent rollers 75, 75 of the roller conveyor 74. The sheet-shaped synthetic rubber 15 can be cut into a constant size while being stably supported on the roller conveyor 74, and excellent processing stability is achieved.

As shown in FIG. 1, a registration roller 76 and a clamper 77 are provided on the upstream side of the cutting device 7, and a weight measuring device 78 is arranged on the downstream side of the cutting device 7. As shown in FIG. The registration rollers 76 function as pressure rollers and drive rollers for registering the cutting position.

The registration rollers 76 rotate in close contact with the sheet-shaped synthetic rubber 15 on the roller conveyor 74, and based on the amount of rotation, feed from a predetermined conveying position where the sheet-shaped synthetic rubber 15 is cut to the tip of the synthetic rubber. It is designed to measure quantity. Further, the weight measuring instrument 78 measures the weight of the synthetic rubber 16 cut in the form of a cut sheet. Then, the predetermined length L of the cut sheet-shaped synthetic rubber 16 is adjusted according to the deviation of the measured weight value from the specified weight value. With this configuration, variations in the weight of the synthetic rubber 16 in the form of cut sheets can be checked one by one, and variations in manufactured products can be suppressed.

In this embodiment, a clamper 77 provided on the upstream side of the cutting device 7 holds the sheet-like synthetic rubber 15 on the roller conveyor 74 when cutting the sheet-like synthetic rubber 15 . . With this configuration, the cooled sheet-like synthetic rubber 15 can be stably supported on the roller conveyor 74 and held by the clamper 77 for cutting, so that processing stability is further improved.

As shown in FIGS. 2(a) and 2(b), the cutting device 7 according to this embodiment includes a cutting blade 70 and a cradle 71. As shown in FIGS. The cutting device 7 further includes a drive section (not shown) for moving the cutting blade 70 up and down, a drive control section (not shown) for controlling the drive by the drive section, and guides the movement of the cutting blade 70. A guide plate 72 is provided.

Specifically, the receiving table 71 is arranged between a pair of rollers 75 , 75 adjacent to each other on the roller conveyor 74 and close to the lower surface of the sheet-like synthetic rubber 15 conveyed on the roller conveyor 74 . The cutting blade 70 is connected to the drive section via a shaft 73, and has a portal shape having side pillars 70b as a pair of guide means that moves up and down along one side surface of the cradle 71 by the drive section. ing. The cutting device 7 cuts the front end portion of the sheet-like synthetic rubber 15 at a predetermined conveying position by raising and lowering the cutting blade 70 by the driving section under the control of the driving control section. With this configuration, the cutting device 7 has a pair of side pillars 70b in which the gate-shaped cutting blade 70 moves up and down along one side surface of the cradle 71. Therefore, the posture of the cutting blade 70 during the up-and-down and cutting operations is stabilized. It can be secured. Note that the cutting blade 70 is not limited to a portal shape, and may be, for example, a rectangular frame shape.

The guide plate 72 is provided with two straight guide grooves 72a which are formed in parallel and vertically with a predetermined interval on one side thereof, and which is provided on the upper surface side of the sheet-shaped synthetic rubber 15 conveyed on the roller conveyor 74. placed in The guide groove 72a of the guide plate 72 is configured to receive and slidably guide a convex guide member 70e provided on one side surface of the plate portion 70d of the cutting blade 70 which is moved up and down by the driving portion. As a result, in the cutting device 7 according to the present embodiment, the guide member 70e of the cutting blade 70 is guided along the guide groove 72a, so that the cutting blade 70 can stably maintain its posture during the lifting and cutting operation. can be done.

Further, as shown in FIG. 2, the cutting blade 70 of the cutting device 7 has a cutting edge line with a different height from the upper surface of the sheet-like synthetic rubber 15 so as to face the upper surface of the sheet-like synthetic rubber 15 on the conveyor. It has a blade portion 70a that continuously changes to . The cutting device 7 guides the cutting blade 70 so that it can be raised and lowered outside the sheet-like synthetic rubber 15 on the conveyor. It is designed to cut with

With this configuration, the continuous sheet-like synthetic rubber having a predetermined width is cut across the entire width direction of the leading edge in the conveying direction by the cutting blade 70 having a different height of the cutting edge line depending on the position of the sheet-like synthetic rubber 15 in the width direction. , it is possible to uniformly cut to a predetermined length and to cut into a good cut surface shape. In addition, since the cutting blade 70 is guided up and down outside the sheet-like synthetic rubber 15, the blade portion 70a is prevented from tilting in the conveying direction, and stable cutting can be achieved. 70b can also easily limit the lateral displacement of the sheet-like synthetic rubber.

In addition, the cutting blades 70 of the cutting device 7 are adjacent to each other in the width direction of the sheet-like synthetic rubber 15 so as to face the upper surface of the sheet-like synthetic rubber 15 on the conveyor and are directed toward the sheet-like synthetic rubber 15 respectively. It has a plurality of protruding blades 70a that protrude out. The protruding blade portion 70a of the cutting blade 70 is moved up and down to cut the sheet-like synthetic rubber 15 in parallel at a plurality of locations in the width direction. As a result, the continuous sheet-shaped synthetic rubber having a predetermined width is cut at multiple points throughout the width direction by the plurality of protruding blade portions 70a adjacent to the sheet-shaped synthetic rubber 15 in the width direction. It can be uniformly cut to a predetermined length and can be cut into a good cut surface shape. The edge line of the projecting blade portion 70a preferably bends at an obtuse angle or an acute angle, more preferably at an obtuse angle.

In addition, the cutting blade 70 of the cutting device 7 has a plurality of side pillars 70b as vertical guides protruding downward from the cutting edge line outside the sheet-like synthetic rubber 15 on the conveyor. In the process, the sheet-shaped synthetic rubber 15 is cut. Further, while the cutting blade 70 is being raised and lowered, the blade portion 70a is guided up and down by the side pillar portions 70b as a plurality of vertical guide portions. As a result, the cutting blade 70 during the cutting process can be guided up and down on both sides in the width direction of the sheet-like synthetic rubber 15, so that the cutting blade 70 can be stably tilted and twisted in the conveying direction regardless of the up-and-down operation position. can be suppressed, and the cutting workability can be improved.

As shown in FIG. 3( a ), the cutting device 7 cuts the sheet-like synthetic rubber 15 with the interval P between the tips of the plurality of blade portions 70 a projecting at an obtuse angle. It is set to be 1 to 3 times the thickness D of . As a result, the sheet-like synthetic rubber 15 is cut at multiple points by the descent of a plurality of blade portions 70a protruding at an obtuse angle, thereby effectively suppressing lateral displacement of the cut portion and vertical displacement of the surface (displacement in the conveying direction). It can be cut into a good cut surface shape.

The cutting blade 70 of the cutting device 7 has a plurality of blade portions 70 a projecting at an obtuse angle, and the cutting edge height H of the triangular waveform is smaller than the thickness D of the sheet-like synthetic rubber 15 . As a result, when the sheet-shaped synthetic rubber 15 is cut at multiple points by descending the plurality of projecting blades 70a, the entire cutting edge is brought close to the upper surface of the synthetic rubber before proceeding with the cutting at multiple points. It is possible to effectively suppress the lateral deviation of the part and the vertical deviation of the surface, and cut it into a good cut surface shape.

As shown in FIG. 3(b), the cutting blade 70 of the cutting device 7 is composed of a cutting edge portion 70c having an acute cutting edge angle forming surface and a plate portion 70d having substantially parallel front and back surfaces. As a result, while suppressing deformation of the cut surface in the conveying direction, the cut sheet-like synthetic rubber 16 can be separated from the succeeding sheet portion at a constant distance when cutting is completed, effectively preventing cutting defects due to adhesion. In addition, each transfer control after separation can be executed independently.

[Bale forming device]
The baling device is a device used in the baling step in the synthetic rubber manufacturing method according to the present embodiment. Specifically, the baling device is adapted to process the dried rubber extruded from the screw-type extruder drier 5 into bales, which are one-piece blocks.

The bale forming apparatus according to the present embodiment is configured so as to be able to manufacture a block of synthetic rubber veil by laminating cut sheets of synthetic rubber 16 cut by the cutting device 7, for example. . The bale-forming device sequentially stacks the cut sheet-shaped synthetic rubber 16 cut by the cutting device 7 on the downstream side of the roller conveyor 74 until it reaches a predetermined thickness or weight to form a block of synthetic rubber bale. to manufacture. As a result, it is possible to efficiently produce a synthetic rubber veil which is easy to handle and has workability such as cutting.

Although the weight and shape of the synthetic rubber bale produced by the bale forming apparatus are not particularly limited, for example, a substantially rectangular parallelepiped synthetic rubber bale weighing about 20 kg is produced.

In this embodiment, the sheet is extruded by the screw-type extrusion dryer 5 to sufficiently reduce the moisture content, and then laminated to form a rubber veil. Compared to , not only is the ease of handling significantly improved, but also the contamination of impurities can be effectively suppressed, and the quality as a material for rubber products can be improved.

When manufacturing an acrylic rubber veil by laminating cut sheet-shaped acrylic rubber, it is preferable to laminate cut sheet-shaped acrylic rubber at 40° C. or higher, for example. By laminating the cut sheet-shaped acrylic rubber at 40°C or higher, good air release is realized by further cooling and compression by its own weight.

<Method for producing synthetic rubber>
Next, a method for manufacturing synthetic rubber such as acrylic rubber using the synthetic rubber manufacturing system described above will be described.

FIG. 4 is a flow chart of a synthetic rubber manufacturing method according to one embodiment of the present invention. As shown in FIG. 4, the synthetic rubber manufacturing method according to the present embodiment includes an emulsion polymerization step S1, a solidification step S2, a washing step S3, an extrusion drying step S4, a conveying cooling step S5, a cutting step S6, and a bale forming step S7. contains. Each step will be described below.

[Emulsion polymerization step]
In the emulsion polymerization step S1, in an emulsion polymerization apparatus, a monomer component for forming a synthetic rubber is mixed with water and an emulsifier, emulsified while appropriately stirred with a stirrer, and emulsion polymerized in the presence of a polymerization catalyst. Thus, an emulsion polymerization liquid (polymer latex) is obtained.

[Coagulation step]
In the coagulation step S2, a polymer latex, a coagulant, and water are each supplied into a coagulation tank at a set temperature and stirred with a stirring device to produce water-containing crumbs. The set temperature in the coagulation tank (the temperature of the aqueous coagulant solution) is controlled by the temperature controller so that it is usually 40°C or higher, preferably 40 to 90°C, more preferably 50 to 80°C.

Specifically, in the coagulation step S2, the polymer latex, the coagulant, and the water are continuously supplied into the coagulation tank at respective supply temperatures and set supply amounts, and are made to flow under agitation. A wet crumb is produced in the coagulation tank depending on the intensity of agitation and the feed and set temperatures. In this embodiment, the emulsion polymerization liquid (polymer latex) is added to the aqueous coagulant solution being stirred in the coagulation tank. The produced water-containing crumbs are allowed to overflow from the coagulation tank together with hot water and taken out of the coagulation tank.

The strength of stirring is determined by the number of revolutions, rotational speed, etc. of the stirring blades of the stirring device. Strong stirring, that is, vigorous stirring is preferable because the grain size of the water-containing crumbs can be made small and uniform. If the strength of stirring is excessively strong, crumb particles having large and small crumb particle sizes will be produced. If the shape and crumb particle size of the produced wet crumbs are uniform and converged within a desired range, the removal of emulsifiers and coagulants during washing and dehydration is remarkably improved, which is preferable.

In the present embodiment, in the coagulation step S2, the polymer latex, the coagulant, and the water are continuously supplied into the coagulation tank at respective supply temperatures and set supply amounts, and stirred. Water-containing crumbs can be continuously produced in the coagulation tank according to the supply temperature and the set temperature, and the produced water-containing crumbs can be overflowed from the coagulation tank together with hot water to be efficiently taken out of the tank.

In addition, the feed water overflowing from the coagulation tank is separated from the water-containing crumb, stored in a tank, and refluxed to be supplied to the coagulation tank again. As a result, the water used in coagulating the polymer latex to form a water-containing crumb can be reused, and the amount of waste water during the production of synthetic rubber can be reduced. In this case, the overflowed hot water can be returned to the coagulation tank side, but a retention tank is provided for passing the overflowed water-containing crumbs and hot water, and the hot water that flows out from the retention tank and is separated from the water-containing crumbs. can be configured to flow back to the retention tank.

[Washing process]
In the washing step S3, the wet crumbs and washing water are supplied to a washing tank at a set washing temperature, and stirred by a stirring device to wash the wet crumbs. The temperature of the washing water in the washing tank is controlled by the temperature control unit so as to be usually 40°C or higher, preferably 40 to 100°C, more preferably 50 to 90°C, and most preferably 60 to 80°C. .

Furthermore, in the washing step S3, the washed wet crumbs are allowed to overflow from the washing tank together with the washing water and taken out of the washing tank. It is supplied to the material feeding zone of machine 5 (crumb feeding step). The temperature of the wet crumbs supplied to the screw-type extruder dryer 5 is preferably 60° C. or higher. The temperature of the wet crumbs is adjusted by directly heating the wet crumbs using a heating device. Alternatively, the temperature of the washing water may be adjusted, or the heating device may be used to directly heat the wet crumbs. and the temperature of the washing water may be adjusted. By setting the set washing temperature to a temperature suitable for the washing and extrusion drying steps, for example, 40° C. or higher, the effect of washing the wet crumbs can be enhanced, and the efficiency of dehydration and extrusion drying can be enhanced.

[Extrusion drying process]
In the extrusion drying step S4, the washed water-containing crumbs are taken into the material supply zone of the screw-type extrusion dryer 5, compressed and dehydrated by the screw-type extrusion dryer 5, and then heated and kneaded to evaporate the water content, thereby obtaining a predetermined water content. The following synthetic rubber is extruded into a sheet.

Specifically, in the extrusion drying step S4, the wet crumbs supplied to the material supply zone are compressed and dehydrated by the screw-type extrusion dryer 5, and then heated and kneaded to evaporate the water content to a predetermined water content or less. Synthetic rubber is continuously extruded into a sheet having a thickness of, for example, 50 mm or less.

Also, the water separated from the water-containing crumbs by compression dehydration in the extrusion drying step S4 is supplied to a tank (not shown). As a result, water having a low coagulant concentration generated for dehydrating the wet crumbs can be reused, and the amount of waste water can be sufficiently reduced.

Note that the dehydration step and the drying step may be performed as different steps. For example, the dehydration step may be performed using a dehydrator such as a centrifugal separator or a squeezer, and the drying step may be performed using a dryer such as a hot air dryer, a reduced pressure dryer, an expander dryer, or a kneader dryer.

[Conveyance cooling process]
In the transport cooling step S5, the sheet-like synthetic rubber 15 extruded from the screw-type extrusion dryer 5 is transported by the conveyor 61 of the transport-type cooling device 6 and cooled to a predetermined cooling temperature.

Specifically, in the transport cooling step S5, the sheet-shaped synthetic rubber 15 extruded from the screw-type extrusion dryer 5 is transported by the conveyor 61 of the transport cooling device 6, and the temperature at the time of extrusion is reduced to 60°C or less. is preferably cooled to a predetermined cooling temperature set between 20°C and 50°C at a cooling rate of 40°C/hr or more. As a result, the sheet-like synthetic rubber 15 can be more stably cut at the front end side of the sheet-like synthetic rubber 15 .

By cooling to a predetermined cooling temperature at a cooling rate of 40° C./hr or more, scorching during processing of the sheet-like synthetic rubber 15 is effectively suppressed, and excellent processing stability can be achieved. In addition, by setting the predetermined cooling temperature between 20° C. and 50° C., for example, the sheet-like cutting process at the front end side of the sheet-like synthetic rubber can be performed in the latter stage of the conveying cooling step S5. The processing of the synthetic rubber 15 can be easily and stably executed.

In addition, the conveying and cooling step S5 may include a conveying step of conveying the synthetic rubber sheet 15 continuous with a predetermined width by a roller conveyer 14 or the like.

[Cutting process]
In the cutting step S6, the sheet-like synthetic rubber 15 cooled by the conveying cooling device 6 is cut by the cutting device 7 to obtain a cut sheet-like synthetic rubber 16. FIG. Specifically, the front end portion of the sheet-shaped synthetic rubber 15 cooled to a predetermined cooling temperature of 60° C. or less by the conveying cooling device 6 is conveyed between the pair of rollers 75 adjacent to each other on the roller conveyor 74 . At the position, the cutting device 7 cuts into cut sheets of a predetermined length.

As a result, while the extrusion temperature in the extrusion drying step S4 is set relatively high to ensure a sufficient extrusion rate, the sheet-like synthetic rubber 15 can be stably cut into cut sheets on the front end side thereof. can. Further, since the front end portion of the sheet-like synthetic rubber 15 cooled to a predetermined cooling temperature is cut into cut sheets between the adjacent rollers 75 of the roller conveyor 74, the cooled sheet-like synthetic rubber 15 can be cut into a constant size while being stably supported on the roller conveyer 74, resulting in excellent processing stability.

In addition, the cooling on the sheet is sufficient to stabilize the shape, and the synthetic rubber veil in which a plurality of cut sheets are substantially integrated can be easily manufactured simply by laminating the cut synthetic rubber 16 in the form of cut sheets. Since it can be produced in a short time, it is a production method that can provide a rubber product with excellent shape stability.

In this embodiment, the cooled sheet-like synthetic rubber 15 is stably supported on the roller conveyor 74 and held by the clamper 77 while the cutting operation is performed, so that the processing stability is further improved. .

Further, in the cutting step S6, based on the amount of rotation of the registration rollers 76 rotating while being in close contact with the sheet-like synthetic rubber 15 on the roller conveyor 74, the synthetic rubber is cut from a predetermined conveying position for cutting the sheet-like synthetic rubber 15. Measure the feed amount to the tip. At the same time, a weight measuring device 78 provided on the downstream side of the cutting device 7 measures the weight of the cut synthetic rubber 16 in the form of a cut sheet. Then, according to the deviation of the measured weight value from the specified weight value, the predetermined length L (the length in the conveying direction) of the cut sheet-like synthetic rubber 16 is adjusted. In this way, variations in the weight of the synthetic rubber 16 in the form of cut sheets can be checked one by one, and variations in manufactured products can be suppressed. As a result, synthetic rubber veils can be produced efficiently while suppressing variations in weight.

Further, in the cutting step S6, the cutting edge 70a has a blade portion 70a continuously inclined at different heights with respect to the upper surface of the sheet-like synthetic rubber 15 so as to face the upper surface of the sheet-like synthetic rubber 15 on the conveyor. A cutting blade 70 is arranged, and the cutting blade 70 is guided up and down outside the sheet-shaped synthetic rubber 15 on the conveyor. Cutting at a predetermined transfer position.

With this configuration, the continuous sheet-like synthetic rubber having a predetermined width is cut across the entire width direction of the leading edge in the conveying direction by the cutting blade 70 having a different height of the cutting edge line depending on the position of the sheet-like synthetic rubber 15 in the width direction. , it is possible to uniformly cut to a predetermined length and to cut into a good cut surface shape. In addition, since the cutting blade 70 is guided up and down outside the sheet-like synthetic rubber 15, the blade portion 70a is prevented from tilting in the conveying direction, and stable cutting can be achieved. Lateral displacement of the sheet-like synthetic rubber can be easily restricted by the portion 70b.

Further, in the cutting step S6, a plurality of slits which are adjacent to each other in the width direction of the sheet-shaped synthetic rubber 15 and protrude toward the sheet-shaped synthetic rubber 15 so as to face the upper surface of the sheet-shaped synthetic rubber 15 on the conveyor. A cutting blade 70 having a blade portion 70a protruding at an obtuse angle is arranged, and the protruding blade portion 70a of the cutting blade 70 is raised and lowered to cut the sheet-like synthetic rubber 15 in parallel at a plurality of locations in the width direction. disconnect. As a result, the continuous sheet-shaped synthetic rubber having a predetermined width is cut at multiple points throughout the width direction by the plurality of protruding blade portions 70a adjacent to the sheet-shaped synthetic rubber 15 in the width direction. It can be uniformly cut to a predetermined length and can be cut into a good cut surface shape.

In the cutting step S6, the cutting blade 70 having a plurality of side pillars 70b as vertical guides protruding downward from the cutting edge line outside the sheet-like synthetic rubber 15 on the conveyor cuts the sheet-like material in the cutting step. The synthetic rubber 15 of is cut. At that time, while the cutting blade 70 is being raised and lowered, the blade portion 70a is guided up and down by the side pillar portions 70b as a plurality of vertical guide portions. As a result, the cutting blade 70 during the cutting process can be guided up and down on both sides in the width direction of the sheet-like synthetic rubber 15, so that the cutting blade 70 can be stably tilted and twisted in the conveying direction regardless of the up-and-down operation position. can be suppressed, and the cutting workability can be improved.

Further, in the cutting step S6, the interval P between the tips of the plurality of blade portions 70a projecting at an obtuse angle and adjacent to each other in the width direction of the sheet-shaped synthetic rubber 15 is set to be equal to or greater than the thickness D of the sheet-shaped synthetic rubber 15. It is set to 3 times or less. As a result, the sheet-like synthetic rubber 15 is cut at multiple points by the descent of a plurality of blade portions 70a protruding at an obtuse angle, thereby effectively suppressing lateral displacement of the cut portion and vertical displacement of the surface (displacement in the conveying direction). It can be cut into a good cut surface shape.

Further, in the cutting step S6, a cutting blade 70 is used in which the height H of the triangular waveform of blade portions 70a projecting at obtuse angles is smaller than the thickness D of the sheet-like synthetic rubber 15. As shown in FIG. As a result, when the sheet-shaped synthetic rubber 15 is cut at multiple points by descending the plurality of projecting blades 70a, the entire cutting edge is brought close to the upper surface of the synthetic rubber before proceeding with the cutting at multiple points. It is possible to effectively suppress the lateral deviation of the part and the vertical deviation of the surface, and cut it into a good cut surface shape.

Further, in the cutting step S6, a cutting blade 70 is used which is composed of a cutting blade portion 70c having an acute cutting edge angle forming surface and a plate portion 70d having front and rear surfaces substantially parallel to each other. As a result, while suppressing deformation of the cut surface in the conveying direction, the cut sheet-like synthetic rubber 16 can be separated from the succeeding sheet portion at a constant distance when cutting is completed, effectively preventing cutting defects due to adhesion. In addition, each transfer control after separation can be executed independently.

[Bale process]
In the baling step S7, dry rubber having a predetermined water content or less is baled. Specifically, the cut sheet-shaped synthetic rubber 16 cut by the cutting device 7 is sequentially stacked and baleed in a bale forming device on the downstream side of the roller conveyor 74 until it reaches a predetermined thickness or a predetermined weight. . As a result, it is possible to efficiently produce a synthetic rubber veil which is easy to handle and has workability such as cutting. The baling can also be performed by putting the dried rubber obtained through the drying process into a baler and compressing it.

In the present embodiment, the rubbery polymer is extruded into a sheet by the screw-type extrusion dryer 5 to sufficiently reduce the moisture content and then layered to form a synthetic rubber veil. Compared to the case, not only is the ease of handling significantly improved, but also the contamination of impurities can be effectively suppressed, and the quality as a material for rubber products can be enhanced.

According to the method for producing synthetic rubber according to the present embodiment, it is possible to efficiently produce synthetic rubber such as acrylic rubber that is suitable for various rubber products that require high-temperature oil resistance, water resistance, storage stability, and the like. In particular, when an emulsion polymerization liquid obtained by emulsion polymerization of a monomer component containing a reactive group-containing monomer in the presence of a divalent phosphoric acid emulsifier is coagulated with a magnesium salt, an acrylic rubber having excellent storage stability and water resistance can be obtained. can be manufactured.

As described above, the present invention has the effect of regulating the tilting of the blade in the conveying direction, effectively suppressing the tilting and twisting of the rubber sheet during cutting, and obtaining a good cut surface. and is useful in all synthetic rubber production methods.

5 screw type extrusion dryer (extrusion dryer)
6 Conveying type cooling device 7 Cutting device 11 Die part 15 Sheet-like synthetic rubber 16 Cut sheet-like synthetic rubber 61 Conveyor 65 Cooling means 70 Cutting blade 70a Blade part 70b Side column part (vertical guide part)
70c cutting edge portion 70d plate portion 71 cradle 72 guide plate 74 roller conveyor 76 registration roller

Claims (6)

a coagulation step of supplying a polymer latex, a coagulant and water into a coagulation tank at a set temperature and agitating them to produce water-containing crumbs;
a washing step of supplying the water-containing crumbs and washing water to a washing tank and agitating them to wash the water-containing crumbs;
The wet crumbs after washing are supplied to the material supply zone of an extrusion dryer, and after being compressed and dewatered by the extrusion dryer, the moisture is evaporated by heating and kneading, and a synthetic rubber having a predetermined moisture content or less is extruded in the form of a sheet. an extrusion drying process;
a conveying step of conveying the extruded sheet-shaped synthetic rubber continuous with a predetermined width by a conveyor;
a cutting step of cutting the tip end portion of the sheet-like synthetic rubber into a cut sheet of a predetermined length on the downstream side of the sheet-like synthetic rubber in the conveying direction, the synthetic rubber manufacturing method comprising:
In the cutting step, a plurality of cutting blades adjacent to each other in the width direction of the sheet-like synthetic rubber and protruding toward the sheet-like synthetic rubber so as to face the upper surface of the sheet-like synthetic rubber on the conveyor. A cutting blade having a protruding blade portion is arranged, and the cutting blade is guided up and down outside the sheet-shaped synthetic rubber on the conveyor, and the plurality of protruding blade portions of the cutting blade are arranged. By bringing the entire blade edge of the blade close to the upper surface of the sheet-shaped synthetic rubber and then lowering it, the sheet-shaped synthetic rubber is cut in parallel at a plurality of locations in the width direction at a predetermined conveying position. A method for manufacturing synthetic rubber. In the cutting step, the sheet-shaped synthetic rubber is cut by a cutting blade having a plurality of vertical guide portions protruding downward from the cutting edge line on the outer side of the sheet-shaped synthetic rubber on the conveyor,
2. The method of manufacturing synthetic rubber according to claim 1 , wherein the cutting blade is vertically guided by the plurality of vertical guides while the cutting blade is being moved up and down. In the cutting step, the distance between the tips of the plurality of protruding blade portions adjacent to each other in the width direction of the sheet-like synthetic rubber is set to 1 to 3 times the thickness of the sheet-like synthetic rubber. The method for producing synthetic rubber according to claim 1 , characterized in that: 4. The synthetic rubber according to claim 1 or 3, wherein, in the cutting step, a cutting blade is used in which the height of the cutting edge of the triangular waveform of the plurality of projecting blade portions is smaller than the thickness of the sheet-like synthetic rubber. Production method. 5. A cutting blade according to any one of claims 1 to 4 , wherein in said cutting step, a cutting blade comprising a cutting blade portion having a cutting edge angle forming surface of an acute angle and a plate portion having front and rear surfaces substantially parallel to each other is used. A method for producing the synthetic rubber according to the item. 6. The method for producing synthetic rubber according to any one of claims 1 to 5 , wherein the synthetic rubber is acrylic rubber.

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