JPS5850644B2 - Continuous manufacturing method for methyl methacrylate resin molding material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing methyl methacrylate resin molding materials, extruded plates, etc. by bulk polymerization or solution polymerization.

More specifically, the present invention removes 25 to 90% by weight of unreacted monomers, solvents, and by-products from a methyl methacrylate polymer composition produced by bulk polymerization or solution polymerization. The present invention relates to a method for manufacturing a molding material by continuously removing volatile components such as products.

The methyl methacrylate-based resin used in the production of molding materials and extruded plates in the method of the present invention is a polymer or copolymer containing methyl methacrylate on a 60-weight plate.
Temperature 210℃, load 10 according to ISK-7210
The extrusion amount (MFI value) for 10 minutes measured under kg conditions is 0.2 to 50.

Methyl methacrylate resins are known to have excellent physical properties such as transparency, weather resistance, heat deformation resistance, and moldability, and are currently mostly produced by suspension polymerization.

However, when a polymer composition obtained by a bulk polymerization method or a solution polymerization method is processed by the method of the present invention, a methyl methacrylate resin with even better physical properties can be produced than when using a conventional suspension polymerization method. In addition, since water is not used and continuous polymerization is possible, it is greatly advantageous in terms of pollution problems, energy saving, and resource saving.

When producing methyl methacrylate polymers by bulk polymerization or solution polymerization, attempting to increase the polymer content in the liquid polymer composition will result in extremely high viscosity of the polymerization system, and Because the calorific value increases, in ordinary continuous polymerization reactors, especially in stirred tank reactors, the polymer content should generally be on a 70-weight plate, although it depends on the polymerization degree of the polymer and the polymerization reaction temperature conditions. It is difficult.

Therefore, in order to maintain the polymer content on a 70-weight plate, it is necessary to use a reactor having a special stirring function and a large heat transfer area.

However, the special reaction equipment is expensive, and even if it is used, if the polymer content exceeds 75% by weight, the stirring power and shear calorific value due to stirring will become large, making it impractical.

That is, it is difficult to reduce the content of volatile components such as unreacted monomers, solvents, and by-products in the polymer composition to less than 25% by weight.

On the other hand, setting the polymer content to less than 10 weight φ is advantageous in that the polymerization system has a low viscosity and the reaction can be easily controlled; This is industrially disadvantageous, as the conditions become harsher, and at the same time, the amount of circulation increases, requiring larger equipment and increasing energy consumption.

25-90% by weight of large amounts of unreacted monomers, solvents and/or
Removal of volatile components from polymer compositions containing by-products or other by-products is a very important technique in the production of methyl methacrylate resin molding materials or extruded plates by bulk polymerization or solution polymerization. However, there are some problems that need to be resolved.

The first is that it is difficult to provide the necessary amount of heat for volatilization by heating the polymer composition, and the second is that the apparent volume increases due to foaming when volatilized in a vacuum or atmospheric pressure. This increase in viscosity makes it difficult to transport, heat, and otherwise handle the polymer composition.

Thirdly, various by-products develop or become colored due to side reactions such as decomposition under high temperature, high pressure, or vacuum conditions, and these are directly affected by residence time. Processing time must be kept as short as possible.

An object of the present invention is to provide an excellent method for solving these technical problems all at once.

Traditionally, the technology for producing molding materials by removing volatile components such as unreacted monomers, solvents and/or by-products from polymer compositions produced by bulk polymerization or solution polymerization has focused on styrene resins. For example, Japanese Patent Publication No. 35-8557, Japanese Patent Publication No. 38-120, Japanese Patent Publication No. 20097-1972, and Japanese Patent Publication No. 45-31.
This method is disclosed in Japanese Patent Application Laid-open No. 678, Japanese Patent Application Laid-open No. 47-27872, and the like.

Methyl methacrylate resins are disclosed in Japanese Patent Publication No. 52-17555, Japanese Patent Application Laid-Open No. 50-88193, and the like.

On the other hand, techniques for extruding polymer compositions using a rotating disk extruder are also disclosed, for example, in Japanese Patent Publication No. 45-2992 and Japanese Patent Publication No. 50-3.
Although it is disclosed in Japanese Patent Application Laid-open No. 9698, Japanese Patent Application Laid-Open No. 48-92463, and Japanese Patent Application Laid-open No. 52-56161, no example is known of removing a large amount of volatile components.

The present invention is produced by a bulk polymerization method or a solution polymerization method, and contains volatile components such as unreacted monomers, solvents and/or by-products of 25 to 90% by weight, preferably 30 to 70% by weight.
In a method for producing a molding material by removing volatile components from a methyl methacrylate polymer composition, the polymer composition is heated at a pressure of 5 to 100 kg/dG, preferably 1
After pressurizing and heating at 0 to 50 kg/dG and a temperature of 150 to 290°C, preferably 180 to 250°C, flashing is performed through the pores under vacuum or atmospheric pressure conditions, without providing a special flash chamber. , the fixed surface and the rotating surface of the rotating disk devolatilizing extruder are configured so that they face each other substantially parallel to each other with a constant gap, and the interior is 50 T.
It is supplied from the fixed surface side of a rotating disc devolatilizing extruder under a vacuum or atmospheric pressure of 200 Torr or more preferably through a small hole provided through the extruder and directly onto the rotating surface. By spraying, most of the volatile components are separated and collected from the outer circumferential direction of the rotating surface, and volume increase due to foaming is minimized, and the polymer composition is This is a method in which volatile components are transferred and reheated by pressure toward the center of the rotating surface and taken out from an outlet provided near the center of the fixed surface, while some volatile components are taken out and recovered from the outer circumference. (a) to one or more devolatilizing extruders operating on substantially the same principle as described above, or (b) to further remove residual volatile components;
The remaining volatile component content in the polymer composition is preferably reduced to 0 by introducing the polymer composition into the feed section of a vent extruder and passing through the interior or vent section thereof while maintaining the temperature at 250 to 290° C. and the pressure at 100 Torr or less. .6 weight or less.

The method of the present invention will be explained below with reference to the accompanying drawings.

FIG. 1 shows a front sectional view of an example of a rotating disk devolatilizing extruder suitable for carrying out the method of the present invention.

It is produced by bulk polymerization method or solution polymerization method and removes volatile components such as unreacted monomers, solvents and/or by-products.
Contains 5-90% by weight, pressure 5-100kg/ci1G
1 The polymer composition pressurized and heated to a temperature of 150 to 290° C. is installed through the stator 2 and the fixing surface 3 from the inlet 1, and is inserted into a small hole with a needle valve 4 for pressure regulation. It is introduced into the gap 6 in the devolatilizing extruder through the part 5 so as to be blown onto the rotating surface T.

A rotor 8 having a rotating surface γ is rotated by a rotating shaft 10 supported by a shaft seal 9.

The fixed surface 3 and the rotating surface 7 face each other with a constant gap, and the gap 6 formed between them is maintained under a vacuum or atmospheric pressure of 50 Torr.

The stator 2 and the rotor 8 are provided with a heat medium circuit 11 for heating the polymer composition in the gap 6 .

The volatile components separated in the gap 6 are led out and collected through an outlet 12 provided in the outer circumferential direction of the rotating surface 7.

In the figure, a concavo-convex portion 13 is provided which has the effect of preventing a part of the polymer composition from being entrained along with the volatile component gas in the outer circumferential direction of the rotating surface γ.

The polymer composition from which most of the volatile components have been separated is transferred to the center of the rotating surface 7 by the hydrodynamic pressure generated by the rotation, during which time the fixed surface 3 and the rotating surface 7
The devolatilization continues to be accelerated by heat transfer from the base, shear heat generation, and surface renewal due to shear.

The polymer composition that has been completely devolatilized is further densified by hydrodynamic pressure and then passed through the outlet port 1 provided near the center of the fixed surface.
It is extracted from 4.

A small screw 16 is placed on the rotor 8 near the outlet port on the same axis as the rotating shaft 10, and an auxiliary pump 15 can be configured with the barrel 1γ at the center of the stator 2.

As is clear from its operating principle, the arrangement of the rotating disk devolatilizing extruder used in the method of the present invention is such that the rotation axis is vertically oriented,
Although it may be horizontal or somewhere in between, it is usually arranged so that the axis of rotation is vertical, as shown in FIG.

When methyl methacrylate polymer compositions used for manufacturing molding materials or extruded plates, etc. are manufactured continuously by bulk polymerization or solution polymerization, there are limitations such as heat balance, prevention of by-product acids, and polymerization stability. Generally, the temperature is 130-17
Polymerization conditions of 0°C and a liquid viscosity of 10-10 to several thousand poise are considered suitable, but conventional methods, such as Japanese Patent Publication No. 52-17
In the method for producing a methyl methacrylate resin molding material disclosed in Publication No. 555, the polymer composition is heated to a temperature of 210° C. or higher prior to devolatilization to provide the amount of heat necessary to separate volatile components. That was essential.

On the other hand, in the method of the present invention, the amount of heat supplied from the outside through the fixed surface 3 and/or the rotating surface 7 of the rotary disk extruder, the amount of heat supplied by high frequency heating and/or dielectric heating, and the amount of heat supplied between the two surfaces Since any amount of heat generated by shearing the composition effectively increases the temperature of the polymer composition, the amount of heat necessary for separating volatile components can be applied without necessarily requiring a special heating device.

Therefore, there is an advantage that polymer compositions containing a large amount of volatile components can also be treated suitably.

Further, a device for heating and raising the temperature of the polymer composition may be additionally used between the polymerization reaction device and the rotating disk devolatilizing extruder.

Due to the high viscosity and thermal denaturation of the polymer composition, the equipment used at this time is a scraped heat exchanger that has as high an overall heat transfer coefficient as possible, has self-cleaning properties, and can shorten residence time, such as a scraped heat exchanger. An extruder type device that rotates a screw with a small flight gap at high speed is suitable.

In the process of the present invention, the polymer composition leaving the polymerization step or heat exchanger is at a temperature of 150-290°C, preferably 180°C.
Since the temperature is at ~250°C and the vapor pressure of volatile components is high, the generation of bubbles in the polymer composition is prevented until it reaches the pore section 5 installed just before the rotating disk devolatilizing extruder. 5 to 100 kg,,'C to suppress and maintain liquid phase state.
ItG is pressurized, preferably at a high pressure of 10 to 50 kg/dG.

Although the pressure in the polymerization step and the heat exchanger may be the same, a pressure booster may be added to the heat exchanger.

The temperature of the polymer composition supplied to the devolatilizing extruder is 150°C
When it is lower than 290, it becomes difficult to sufficiently reduce the residual volatile content in the devolatilized polymer composition;
When the temperature is higher than .degree. C., the polymer composition itself is thermally altered and deteriorated, which is not preferable.

Furthermore, when the pressure applied to the polymer composition is lower than 5 kg/dG, bubbles are generated due to boiling of volatile components, making it difficult to maintain the liquid phase state;
Setting it higher than G not only has no particular advantage, but also increases the burden on manufacturing and operation of the device, both of which are undesirable.

The polymer composition under high temperature and high pressure passes through the pores 5.
It is directly discharged onto the rotating surface 7 provided in a vacuum or atmospheric pressure atmosphere of 0 Torr.

At this time, if the pressure inside the devolatilizing extruder is higher than atmospheric pressure, the separation of volatile components will be insufficient, while if it is lower than 50 Torr, the residual volatile content in the polymer composition can be reduced, but the pores 5 The apparent specific gravity after being ejected from the gas decreases and the volume increases, the temperature decreases, the condensation device for volatile components becomes excessively large, and the processing capacity decreases due to the inability to quickly develop hydrodynamic pressure. Both are undesirable because preventing leakage from the shaft sealing portion 9 of the rotor 8 becomes complicated.

The functions of the pores 5 include creating the necessary pressure drop as a boundary between the high pressure section and the low pressure section, and increasing the flow rate of the discharged polymer composition to aid in the separation of volatile components.

Pressure loss primarily depends on the viscosity of the polymer composition as long as it maintains a liquid phase state, but in reality it depends on the concentration increase due to foaming in the middle of the pores 5, Since viscosity increases due to temperature drop, etc., it acts in self-equilibrium within a certain range and maintains a steady state.

However, if the pressure loss is too small or if the pressure loss upstream of the pore section 5 is relatively large,
The flow becomes unstable due to the blow-through of volatile components,
Local thickening due to foaming in a heat exchanger or the like is undesirable as it may cause stagnation of flow and cause alteration or deterioration, so the pressure required to maintain the polymer composition in a liquid phase is The pressure loss in the pores 5 is adjusted so that it can be obtained at all times.

In addition, since the above-mentioned blow-through and stagnation are undesirable in the connecting part from the pore part 5 to the inside of the rotating disk devolatilizing extruder, the pore part 5 should be placed as close as possible immediately before the devolatilizing space inside the extruder. It is preferably installed from the fixed surface 3 through it, and is arranged so that the polymer composition is sprayed directly onto the opposing rotating surface 7.

In the method of the present invention, the number of pores 5 may be one or a small number, and usually one or two to three pores are installed symmetrically with respect to the center of the rotor 8.

Conceptually, the step of separating volatile components from the polymer composition in the rotating disk devolatilizing extruder in the method of the present invention consists of two steps.

The first is a process in which volatile components corresponding to the amount of heat added to the polymer composition in the preceding polymerization step or in a heat exchanger instantaneously cause rapid volatilization and foaming in the vicinity of the pores 5 and are separated. The second is that while the polymer composition is transferred toward the center of the rotating surface 7 by the hydrodynamic pressure generated by the rotation of the disk, additional supply is provided by external heat transfer or shear heat generation of the polymer composition. The amount of heat applied and the effect of renewing the volatilization interface due to shear combine to substantially complete most of the devolatilization.

However, these two processes actually proceed concurrently;
A high level of devolatilization is easily achieved in virtually one step.

Conventionally, attempts have been made to extrude polymer compositions in the form of strands or thin films through multiple holes with the aim of increasing the evaporation area. In order to reduce the difficulty of handling such as heating or transporting the polymer composition, the heat necessary to separate the volatile components is applied to the polymer composition in advance, and a special flash is applied when the polymer composition is ejected from the pores. without setting up a room,
A method has also been proposed in which by spraying directly onto the screw of a devolatilizing extruder from a short distance, the bulky and extremely large evaporation area can be shortened, and yet most of the volatilization can be substantially completed.

According to the method of the present invention, rapid volatilization and foaming occur instantaneously in the vicinity of the sunrise of the pore portion 5, but before the explosive force causes very large foaming to occur, the foam is blown onto the opposing rotating surface 7. The volatile components are smoothly collected from the outer circumferential direction of the rotating surface 7, and the volume increase due to foaming is suppressed to a minimum, and the volatile components are separated. Even while the polymer composition is being transferred toward the center of the rotating surface 7, it is constantly kneaded by the large shearing force acting in the circumferential direction on the rotating surface T, thereby renewing the evaporation surface. A polymer composition that is bulky and has a large evaporation area for a very short time, and during this time, heat is transferred from the fixed surface 3 and/or the rotating surface 1 by a high overall heat transfer coefficient or heat generated due to the shearing force. Since the heating temperature is uniformly increased in a very short period of time, the separation of volatile components is accelerated and continued, and the content of residual volatile components in the polymer composition can be reduced very efficiently.

Moreover, the polymer composition from which most of the volatile components have been separated is immediately densified by the hydrodynamic pressure and is deposited on the fixed surface 3.
Since it is taken out from the outlet 14 provided near the center of the polymer, the residence time under high temperature conditions can be extremely short, and even when processing polymer compositions containing thermally unstable components, deterioration and deterioration can be prevented. It also has the advantage of being less likely to cause such problems.

Hydrodynamic pressure primarily refers to centripetal force based on a phenomenon called normal stress action or the Weissenberge effect.

This phenomenon was discovered by Weissenberg (Nature, Vol. 159, p. 310, published in 1947). When a circumferential shearing force is applied to a viscoelastic material, the stress acting in the direction perpendicular to the shearing force, that is, the This means that linear stress occurs.

The rotating surface 7 and fixed surface 3 in the present invention cooperate by rotation to create a hydrodynamic pressure that moves the polymer composition toward the center of rotation and removes unreacted monomers, solvents and/or by-products. It can be of any shape as long as it has the function of extracting the volatile components of objects in a direction opposite to the direction of the center of rotation, but generally it is a disk, cone, cylinder, sphere, or a combination of these, such as a truncated cone. is used.

In addition, although smooth surfaces are generally used for the rotating surface 7 and the fixed surface 3, in order to increase the heat transfer area or increase the centripetal force by pumping action, special uneven shapes may be used, such as spiral or radial protrusions, logarithmic spirals, etc. It may also have grooves or concentric rows of inclined blades.

The pore portion 5 provided on the fixed surface 3 side is located at an intermediate position between the center and the peripheral portion on the rotating surface 7, preferably from 0.2 to 0 in the radial direction.
．． They are placed facing each other at 8x positions.

If the pores 5 are too close to the center of the rotating surface 7, the volatile components will be discharged from the outlet 14 provided near the center of the fixed surface 3 without being sufficiently separated. If it is too close to the periphery of the rotating surface 7, the polymer composition will reach the periphery without sufficient hydrodynamic pressure being developed and will be mixed into the volatile component outlet provided in the outer circumferential direction of the rotating surface 7 and discharged. Neither is preferable.

In order to supply the polymer composition with the necessary and sufficient amount of heat for volatilization by heat transfer from the rotating surface γ and/or the fixed surface 3,
The rotor 8 and/or the stator 2 have a heat medium circulation path through which heated heat medium or steam can circulate.

The temperature of the heat medium is usually 180 to 320°C, preferably 20°C.
Selected between 0 and 290'C.

If it is lower than this range, the separation of volatile components will be insufficient, while if it is higher than this range, the polymer composition will undergo deterioration, which is not preferable.

Further, the temperature of the polymer composition and the degree of vacuum in the devolatilizing extruder are selected so that the temperature when sprayed onto the rotating surface T through the pores 5 is 120° C. or higher.

At this time, since hydrodynamic pressure can be developed quickly, the device efficiency of the devolatilization extruder can be particularly high, which has the advantage that the device can be miniaturized.

In the method of the present invention, the content of residual volatile components in the polymer composition after devolatilization can be easily reduced to 5% by weight or less,
The weight of the rice cake is usually 0.3 to 5, and the apparent specific gravity is between 0.5 and 1°2.

Reducing the content to less than 0.3% by weight requires harsh temperature and vacuum conditions, which reduces processing capacity and is not a good idea.

Under preferred operating conditions, one-step devolatilization results in a residual volatile component content of 0.3-1.0% by weight and an apparent specific gravity of 1.0% by weight.
15 to 1.2, it was a surprising discovery that a polymer composition containing no air bubbles could be obtained.

The polymer composition obtained here can be used as a molding material as it is by cooling, cutting and packaging in a conventional manner.

The higher the temperature, the higher the degree of vacuum, and the stronger the shearing force, the lower the residual volatile content becomes.

On the other hand, the lower the temperature, the lower the degree of vacuum, and the weaker the shearing force, the smaller the apparent specific gravity becomes and the bulkier the material becomes.

After careful consideration of the best option for reducing the residual volatile content and increasing the apparent specific gravity, we determined that the temperature of the polymer composition and the degree of vacuum in the devolatilizing extruder were within the ranges mentioned above. It has been recognized that it is effective to select the optimum conditions for the shearing force by adjusting the gap between the rotating surface 7 and the fixed surface 3 and the rotational speed.

This interplanar gap is usually selected to be between 0.2 and 20. If it is narrower than this range, it is difficult to smoothly increase the volume due to foaming. On the other hand, if it is wider than this range, the shearing force becomes weaker and no Undesirable.

Also, the rotation speed is 50 to 1000 rpm, preferably 10
The speed is selected to be 0 to 500 rpm; if the speed is lower than this range, the required hydrodynamic pressure cannot be obtained, and if it is higher, the hydrodynamic pressure due to the centrifugal force is canceled out, which is not preferable.

The rotating disc devolatilizing extruder in the method of the present invention is used in one step to reduce the residual volatile component content in the polymer composition to a level of 0.3 to 1.0% by weight, which is suitable for use as a molding material. However, in order to absorb fluctuations in operating conditions and stably obtain a homogeneous molding material over a long period of time, it is necessary to keep the devolatilization at a certain level in the first stage, and then remove the remaining volatile components in the second and subsequent stages. It is preferable to do so.

At this time, it is not necessarily advisable to increase the degree of vacuum in the first stage devolatilizing section, and an atmosphere of 50 Torr vacuum or atmospheric pressure, preferably 200 Torr vacuum or atmospheric pressure, is selected to remove residual volatilization in the polymer composition. Ingredient content is reduced by 1 to 5 weights.

From the second stage devolatilizing section onwards, one or more of the above-mentioned rotating disk devolatilizing extruders may be used in series, or a conventionally known vent extruder may be used.

At this time, the volatile components of 5 weight φ or less left in the polymer composition after the first stage devolatilization are removed from the gap or pant under conditions such as a temperature of 250 to 290°C and a pressure of 100 Torr or less.
Preferably, the separation is carried out under conditions of 50 to 5 Torr, so that the final residual volatile components can be reduced to 0.6% by weight or less, preferably 0.3% by weight or less.

As an example of the above-described process, FIG. 2 shows a flow sheet of a process for producing a methyl methacrylate resin molding material according to the present invention when two devolatilizing extruders are used in series.

In the method of the present invention, the methyl methacrylate-based polymer is a homopolymer of methyl methacrylate or an alkyl methacrylate (provided that the alkyl group is 8 carbon atoms), styrene and its halogen-substituted or alkyl-substituted derivatives, vinyl acetate, acrylonitrile or its derivatives, acrylamide or its derivatives, acrylic acid or its derivatives,
A copolymer formed by polymerizing a monomer mixture mainly composed of methyl methacrylate and containing one or more of various vinyl compounds such as alkyl acrylate (wherein the alkyl group has 1 to 8 carbon atoms). means a polymer.

The methyl methacrylate polymer also contains 1 to 20 parts by weight of the methyl methacrylate monomer or the monomer mixture containing methyl methacrylate as a main component.
Part by weight of a rubbery polymer such as polybutadiene, styrene/butadiene copolymer, ethylene/vinyl acetate copolymer, ethylene/alkyl acrylate (wherein the alkyl group has 1 to 8 carbon atoms) is dissolved. A graft copolymer obtained by polymerizing a raw material liquid can be included.

These vinyl compounds or rubber-like polymers are generally used in amounts within this range to improve various qualities of the resulting molding material or extruded plate as long as they do not impair the characteristics of the methyl methacrylate resin.

Furthermore, in the present invention, if necessary, the above monomer or monomer mixture, or a polymer composition produced by a bulk polymerization method or a solution polymerization method, may be added in an amount within a range that achieves the object of the present invention. It may contain a heat stabilizer, an ultraviolet absorber, a colorant, a plasticizer, a mold release agent, a crosslinking agent, and various fillers.

The method of the present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples.

Example 1 92 parts of methyl methacrylate, 8 parts of ethyl acrylate, 0.0015 parts of di-tert-butyl peroxide and 0.2 parts of tert-butyl mecabutane were mixed in a mixing tank with stirring under a nitrogen stream, and then mixed with a metering pump. The pressure was continuously increased and supplied to the stirred tank type polymerization reactor at a rate of 71/hr.

The reaction temperature in the polymerization reactor is 160°C and the pressure is 15
kg/dG and the average residence time was maintained at 4.5 hours to obtain a polymer composition containing 62% by weight of a copolymer with a number average degree of polymerization of 560.

After heating and raising the temperature to 200°C using a screw heat exchanger while maintaining the pressure at 15°C, a small hole 5 was formed in the fixing surface 3 of a rotating disc devolatilizing extruder as shown in Fig. 1. It was sprayed directly onto the rotating surface 7 which was rotating at 300 rpm.

At this time, the inside of the devolatilizing extruder is maintained at 260 Torr, and the temperature in the heat medium circulation path 11 provided in the stator 2 is maintained at 250°C.
of heating medium was circulated.

The polymer composition from which volatile components had been separated was taken out at a rate of 4.17 kg/hr through an outlet 14 provided at the center of the fixed surface 3.

The final polymer composition had an apparent specific gravity of 1.19, a residual volatile component content of 0.7% by weight, an MFI value of 11, ■, and was colorless and transparent without containing any air bubbles.

The separated volatile components were condensed in a condenser, collected in a storage tank, and then sent to a mixing tank for reuse.

The rotary disc devolatilizing extruder used here has a nozzle having an inner diameter of 2 mrn and a length of 10,757 m, and a needle valve 4 for adjusting pressure loss is provided upstream of the nozzle.

The diameter of the rotating surface 7 is 160 peaks, the distance from the center of the rotation axis of the pore 5 is 40 mm, the inner diameter of the fixed surface 3 is 180 mrIL,
The surface gap 6 is 2.2 mm, and the demister part 13 has a pitch of 6.
The peak/valley height was 6 mm in mm, and the nozzle of the polymer composition outlet 14 had an inner diameter of 5 mm and a length of 50 mm.

Example 2 According to the flow shown in Fig. 2, the same raw materials used in Example 1 were used at a rate of 1013/hr in the same manner as in Example 1, such as a mixing tank 18, a pump 19, a stirred tank type polymerization reactor 20, and a screw type polymerization reactor. Number average degree of polymerization obtained through heat exchanger 21: 560, polymer content: 62 weight, temperature: 180°C, pressure: 1
A polymer composition of 5 kg/dG was fed to two rotating disc devolatilizing extruders 22 and 23 arranged in series to separate volatile components.

At this time, the inside of the first stage devolatilizing extruder 22 is 250°C and atmospheric pressure, and the inside of the second stage devolatilizing extruder 23 is 270°C and 50T.
orr, and the rotational speed of the rotor is 3QQ, respectively.
rpm and maintained at 150 rpm.

Further, an auxiliary pump was attached to the polymer composition outlet of the first stage devolatilizing extruder 22, and the pressure at which the polymer composition was discharged was increased to 25.9/dG.

5.9 kg/h from the outlet of the second stage devolatilizing extruder 23
A final polymer composition of r was removed, which had an apparent specific gravity of 1.19, a residual volatile content of 0.1% by weight, an MFI
It had a value of 9.8 and was colorless and transparent with no bubbles.

On the other hand, the separated volatile components are each transferred to a devolatilizing extruder 22.2.
The condensed materials were separately supplied to condensers 24 and 27 from 3, collected in storage tanks 25 and 28, combined, and sent to a mixing tank 18 for reuse.

Comparative Example 1 A polymer composition having a number average degree of polymerization of 5601 and a polymer content of 62 weight, obtained in the same manner as in Example 1, was heated to 200° C. using a screw heat exchanger under 15 atm. 260
Flushed into a flash bath maintained at TOrr.

The content of residual volatile components in the polymer composition after devolatilization was 7.2% by weight, and the apparent specific gravity was 0.1 or less, and the properties were unsuitable for handling as a molding material.

Example 3 A monomer mixture consisting of 70% by weight of methyl methacrylate and % by weight of Stere was polymerized by bulk polymerization, and the polymer content was 30.8% by weight, and the number average degree of polymerization of the copolymer was 30.8% by weight. 405, a polymer composition with a styrene content of 34.8% by weight was heated to a temperature of 180° C. and a pressure of 15 kg/dG, and the interplanar gap was Q, 8 mtn.

It is the same as Example 1 except that the rotation speed is 55 Or-.

It was continuously fed to a rotating disk devolatilizing extruder to separate volatile components.

The inside of the extruder was maintained at 240° C. and 160 Torr.

The final polymer composition obtained at approximately 0.5 kg/hr was colorless and transparent without any air bubbles, and the residual volatile component content was 0.8% by weight, including 0.6% by weight of methyl methacrylate and styrene. It was 0.2% by weight.

[Brief explanation of drawings]

Figure 1 is a front sectional view of an example of a rotating disk devolatilizing extruder suitable for carrying out the method of the present invention, and Figure 2 is a process for producing methyl methacrylate resin molding materials that includes the same rotating disk devolatilizing extruder in the process. An example of a flow sheet is shown in each case. 1 and 2, 1 is a polymer composition inlet; 2 is a polymer composition inlet;
is a stator, 3 is a fixed surface, 4 is a needle valve, 5 is a pore part,
6 is a gap, 7 is a rotating surface, 8 is a rotor, 9 is a shaft seal, 1
0 is a rotating shaft, 11 is a heat medium circulation path, 12 is a volatile component outlet,
13 is an uneven part, 14 is a polymer composition outlet, 15 is an auxiliary pump, 16 is a small screw, 17 is a barrel, 18 is a raw material preparation tank, 19 is a pump, 20 is a polymerization reaction tank, 21 is a heat exchanger, 22 , 23 is a devolatilizing extruder, 24 and 27 are condensers, 25 and 29 are storage tanks, and 26 and 28 are vacuum pumps.

Claims (1)

[Claims] 1. Bulk polymerization method or solution polymerization method (produced by this method,
In a method for producing a molding material by removing volatile components from a methyl methacrylate polymer composition containing volatile components of unreacted monomers, solvents and/or by-products,
The composition is heated at a pressure of 5 to 100 kg/dG and a temperature of 150 to 2
After adjusting the temperature to 90°C, the fixed surface and the rotating surface are configured so that they face each other substantially parallel to each other and are spaced apart from each other at a constant distance.
The interior is under vacuum or atmospheric pressure conditions of 50 Torr, and the rotational speed of the disc is 50 to 1.5 Torr. It is supplied from the fixed surface side of the rotating disc devolatilizing extruder (OQ Orpm) through the pores provided through the fixed surface, and is sprayed directly onto the rotating surface to separate most of the volatile components and remove the volatile components from the outer periphery of the rotating surface. At the same time, the polymer composition is transferred and heated toward the center of the rotating surface by the hydrodynamic pressure generated by the rotation of the disk, and is taken out from the outlet provided at the center of the fixed surface. A continuous manufacturing method for a methyl methacrylate resin molding material. 2. The method according to claim 1, wherein the methyl methacrylate polymer is a methyl methacrylate homopolymer or a copolymer containing 60 ★ or more by weight of methyl methacrylate. 3 The volatile component content in the supplied polymer composition is 25
9. The method of claim 1, wherein the weight is greater than 90% by weight. 4. The method according to claim 1, wherein the pore portion is arranged on the fixed surface facing the rotating surface at a position 0.2 to 0.8 times the radius in the radial direction from the center of the rotating surface. 5. The method according to claim 1, wherein the rotating surface and/or the stationary surface is heated by a heat medium at 180 to 320°C. 6. The method according to claim 1, wherein the surface gap between the rotating surface and the fixed surface is 0.2 to 20 nm. 7. The method according to claim 1, wherein the content of residual volatile components in the polymer composition to be removed is 0.3 to 5% by weight. 8. A molding material is produced by removing volatile components from a methyl methacrylate polymer composition produced by a bulk polymerization method or a solution polymerization method and containing volatile components of unreacted monomers, solvents, and/or by-products. In the method of
After adjusting the temperature to 0°C, the fixed surface and the rotating surface are arranged so that they face each other substantially parallel to each other and are spaced apart from each other, and the inside is under a vacuum of 50 Torr or atmospheric pressure, and the disk is formed. The rotation speed of 50~1. It is supplied from the fixed side of a rotating disc devolatilizing extruder (OOOrpm) through the pores provided through it, and is sprayed directly onto the rotating surface to separate most of the volatile components and remove the volatile components from the outer periphery of the rotating surface. At the same time, the polymer composition is transferred and heated toward the center of the rotating surface by the hydrodynamic pressure generated by the rotation of the disk, and is taken out from the outlet provided at the center of the fixed surface. Further, the composition is configured such that the fixed surface and the rotating surface are substantially parallel to each other and are spaced apart from each other, and the inside is heated at a pressure of 100 Torr or less, a temperature of 250 to 290°C, and a temperature of 50 to 1, 000rpII
Supplied from the fixed surface side of the rotating disk devolatilizing extruder under the rotational speed condition of 1 through the pores provided through it,
By spraying directly onto the rotating surface, most of the volatile components are separated and recovered from the outer periphery of the rotating surface, and the polymer composition is also sprayed toward the center of the rotating surface using hydrodynamic pressure generated by the rotation of the disk. The composition is transferred to and heated at a pressure of 100 Torr or less, a temperature of 250 to 290°C, and a temperature of 50 to 1.00 Orr.
1. A continuous production method for a methyl methacrylate resin molding material, which comprises supplying and extruding a vented extruder under a rotational speed condition of pm.