RU2458936C1 - Apparatus for producing polymer resins, polymerisation vessel and method of producing polymer resins - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: apparatus for producing polymer resin includes a polymerisation vessel, a support element, a protective element, a closed-cycle cooling apparatus, a starting material inlet channel and an element which defines the flow channel. The protective element forms a first flow channel between itself and the side surface of an axial mixer. The closed-cycle cooling apparatus includes a circulation inlet channel lying on the side surface of the protruding part opposite the protective element. The element which defines the flow channel lies between the support element and the protective element so as to close the side surface of the axial mixer and fix the support element and the protective element. Said element which defines the flow channel forms a second flow channel between itself and the side surface of the axial mixer, and a third flow channel for connecting the second flow channel with the starting material inlet channel. The flow channels from the first to the third make up a continuous flow channel, and the highest end of the first flow channel is open inside the protruding part. The gap, part of the first flow channel other than the highest end, the second flow channel and third flow channel are insulated from the inner zone of the protruding part. Disclosed also is a method of producing a polymer resin and a polymerisation vessel for the polymer resin.

EFFECT: obtaining resin of high transparency, ensuring complete and homogeneous mixing and polymerisation of the starting material, improved removal of polymerisation reaction heat.

14 cl, 1 tbl, 7 dwg, 2 ex

Description

FIELD OF THE INVENTION

The present invention relates to a device and method for producing polymer resins. Advantageously, the present invention relates to a manufacturing apparatus and a manufacturing method used to produce high transparency resins, such as resins based on a styrene-acryloniryl copolymer (SAN) and resins based on a methacrylate-styrene copolymer (MS), which are copolymer resins.

State of the art

Traditionally, resins based on styrene-acrylonitrile copolymers (hereinafter sometimes abbreviated as "SAN") are industrial products. SAN data is obtained in a continuous manner to improve the performance of the process of obtaining it, or the like.

On the other hand, SANs are prepared by the copolymerization reaction of styrene and acrylonitrile, which are the starting materials, and this copolymerization reaction is an exothermic reaction. Accordingly, it becomes necessary to remove the heat of polymerization in order to ensure continuous production of SAN in a stable manner. Therefore, as an apparatus for the production of this SAN, an apparatus was proposed that includes a spatial region inside the polymerization tank, by means of which the heat of polymerization is removed due to the evaporation of part of the polymerization solution in this spatial region.

Surprisingly, this SAN has excellent transparency performance. However, this transparency worsens as the SAN becomes cloudy if the composition of the SAN, i.e. the components of styrene and acrylonitrile in the SAN vary massively. Accordingly, in order to obtain an SAN with excellent transparency, it is necessary to ensure uniformity of composition and temperature of the polymerization solution within the polymerization tank.

However, in the production apparatus, including the spatial region inside the polymerization tank, as described above, by which heat is removed in the form of latent heat, the composition of the evaporated monomer, solvent, etc. and their composition in the polymerization solution is different from each other. If these vapors are condensed and fed back into the polymerization tank, a region arises in which the concentration of these components in the polymerization solution is different. In addition, operating factors, such as pressure, temperature, and fluid level, influence each other in this unit and therefore are constantly changing. Therefore, the residence time and the polymerization ratio change, thereby making it difficult to keep the residence time and the polymerization ratio constant. As a result of this, the composition of the SAN obtained by the copolymerization reaction becomes heterogeneous, which affects the transparency of the SAN.

Therefore, a convenient manufacturing apparatus was proposed, including a cooler, with the help of which the heat of the polymerization reaction is removed.

Japanese Patent Publication No. 47-610 discloses a manufacturing apparatus including a cooling device inside a polymerization vessel, by which heat of polymerization is removed. This production apparatus has such a property that eliminates the need for a spatial region inside the polymerization tank. Therefore, it is possible to maintain a constant residence time of the polymerization solution inside the polymerization tank by keeping the flow rate of the starting material constant. In addition, the production apparatus has the advantage that it is not necessary to take into account a change in composition due to condensation of the vapor component.

Japanese Patent Publication No. 55-35912 discloses an external heat removal apparatus (cooler) capable of cleaning the inside wall of a pipe. A cooling medium having a temperature that is 5 ° C or more lower than the polymerization temperature, but not more than 40 ° C, flows through the jacket of this unit to remove heat (cooler). Removing the polymerization solution from the polymerization tank using a pump and introducing the solution into the pipe inside this apparatus for heat removal, heat exchange is carried out between the polymerization solution and the cooling medium, as a result of which the polymerization solution is cooled. After that, the polymerization solution is again fed into the polymerization tank to remove the heat of polymerization inside the polymerization tank.

Japanese Patent Publication No. 48-29628 discloses a manufacturing apparatus comprising a polymerization vessel having an axial mixing blade in its lower part, consisting of a turbine-type mixing blade and a screw-type mixing blade and having a cooler in its interior.

SUMMARY OF THE INVENTION

However, the production apparatuses disclosed in Japanese Patent Publications Nos. 47-610, 55-35812 and 48-29628, in some cases, cannot ensure complete and uniform mixing and the reaction of the copolymerization of the starting material and the polymerization solution, which leads to an uneven composition of such SAN image.

This means that even if cooling is carried out using a cooling device, it is necessary to ensure a certain polymerization reaction rate in order to achieve efficient SAN production. For this reason, the polymerization solution inside the polymerization vessel is maintained at a temperature higher than the temperature of the starting material introduced into the polymerization vessel. Hence, as shown in figures 1 and 2, the starting material is introduced into the polymerization tank through the injection inlets 4 and 10 in the case of the production apparatus disclosed in Japanese Patent Publication No. 47-610. Accordingly, the temperature and composition of the polymerization solution in some cases become non-uniform near the given injection inlets 4 and 10, also causing a non-uniform composition of the resulting SAN. In addition, this production apparatus only includes, as its coolers, a cooling device mounted in the polymerization tank and a cooling jacket covering the outer wall of the polymerization tank. The result of this is that the heat removal from the production apparatus turned out to be insufficient, since the heat transfer area per unit volume of the polymerization capacity decreases due to an increase in the size of the apparatus. Accordingly, the apparatus according to Japanese Patent Publication No. 47-610 is considered not fully adapted to increase in size.

Japanese Patent Publication No. 55-35912 does not specifically disclose any method of introducing the starting material into the polymerization vessel, mixing and mixing the starting material. As not discussed in Japanese Patent Publication No. 55-35912, a method for increasing the uniformity of the temperature distribution and the composition of the polymerization solution near the injection site of the starting material inside the polymerization vessel. In addition, in the case when the polymerization solution inside the polymerization tank is circulated through an external cooling device, as in this production apparatus, the production apparatus in some cases undergoes a negative effect due to the fact that the axial stirrer of the mixing device inside the polymerization tank moves sideways under pressure liquids of a given circulating polymerization solution when the circulating polymerization solution is fed back to the polymerization th container.

The manufacturing apparatus according to Japanese Patent Publication No. 48-29628 includes an axial mixing blade 7 and a screw type mixing blade 3, as shown in FIG. 1. Accordingly, it is possible to improve the miscibility of the starting materials. However, like the production apparatus according to Japanese Patent Publication No. 47-610, this production apparatus only includes, as cooling devices, a cooling device mounted in the polymerization tank and a cooling jacket covering the outer wall of the polymerization tank. Therefore, if you simply increase the size of the apparatus, as discussed above, it is impossible to completely remove the heat of polymerization, and therefore external cooling is required.

In addition, in the apparatus according to Japanese Patent Publication No. 48-29628, the axial mixer itself is lengthened if the apparatus size is increased, and the lateral displacement due to rotation of the mixing blade becomes larger. Therefore, in order to prevent this situation from arising, it is necessary to control the axial mixer by installing a support element in the lower part of the polymerization tank. However, if the support element is placed at the bottom of the polymerization tank, as shown in Figure 1 of Japanese Patent Publication No. 48-29628, it is difficult to establish an input for introducing the starting material and an input for the polymerization solution circulating from the outside immediately under the mixing paddle. Therefore, in this case, the inputs for introducing the starting material and the solution circulating from the outside should be located in position 10, which is separated from the position immediately below the mixing paddle inside the polymerization tank, as shown in figure 2 of Japanese Patent Publication No. 47-610. As a result, it is impossible to evenly mix and mix the polymerization solution near input 10, which causes uneven temperature and composition. In addition, it is impossible to quickly and evenly mix the polymerization solution circulating through the external cooler and cooling as a result of this, and the starting material inside the polymerization tank.

As discussed above, in traditional production apparatuses, the inlets for introducing the starting material and the solution circulating externally should be located at a distance from the axial mixer. Therefore, the operation of such an apparatus should be associated with the problem of unevenness in temperature and composition of the polymerization solution near the point of entry of the starting material into the polymerization tank, and therefore, the resulting SAN is inferior in terms of transparency. In addition, if the cooling efficiency of the polymerization solution is insufficient and therefore an external cooler of a circulation type is installed in order to increase the cooling efficiency, in production devices in some cases there is a negative effect associated with lateral displacement of the axial stirrer inside the polymerization tank due to the pressure of the liquid of the polymerization solution passed through this cooler.

An explanation is given in the chapter on the history of the invention by the example of SAN, which is a copolymer-based resin. However, such a problem as the uneven temperature and composition of the polymerization solution inside the polymerization tank, which is visible in the process of obtaining this SAN, also arises when the continuous production of other polymer and copolymer resins proceeds through the polymerization reaction, which is an exothermic reaction.

In order to solve the above problem, one embodiment of the invention has been proposed which relates to an apparatus for producing a polymer resin, including

a polymerization tank including a main body and a protruding part that protrudes downward from the plane of the bottom of the main body, and the lower part of which represents a cover for the bottom;

a mixing device comprising a drive mounted above the main body, a rotating axial mixer connected to the drive and extending from the drive to the protruding part, and a blade located on the side surface of the axial mixer;

a support element located on the lower cover of the protruding part so as to close the side surface of the axial mixer without contact with it, and so that a gap is formed between the support element and the side surface of the axial mixer;

a hole for draining the solution from the main body;

a protective element covering the side surface of the axial mixer without contact with it and forming a first flow channel between the protective element and the side surface of the axial mixer inside the protruding part;

first cooling means located inside the main body;

circulation cooling means including a circulation inlet channel located on a side surface of the protruding part so as to be on the opposite side of the protruding part, a circulation line extending from the main body to the circulation inlet channel, a second cooling means and a circulation pump connected to the circulation line in the middle point;

third cooling means arranged so as to close the outer wall of the polymerization vessel;

a feed input channel connected to the protruding portion, and

an element defining a flow channel and located between the support element and the protective element so as to close the side surface of the axial mixer, and so as to fix the support element and the protective element defining the flow channel; an element forming a second flow channel between the side surface of the axial mixer and the defining channel element flow, and a third flow channel for connecting the second flow channel to the input channel of the source material;

moreover, from the first to the third flow channels constitute a continuous flow channel,

the highest end of the first flow channel is open inside the protruding part; and

the gap, part of the first flow channel, with the exception of the highest end, the second flow channel and the third flow channel are isolated from the inner zone of the protruding part.

Another embodiment of the invention relates to a polymerization tank for a polymer resin, including

main building;

a protruding portion that protrudes downward from the plane of the bottom of the main body and which includes a lower portion that represents the bottom cover;

a mixing device comprising a rotary axial mixer connected to a drive element mounted above the main body and extending from the drive element to the protruding part, and a blade located on the side surface of the axial mixer;

a support element located on the lower cover of the protruding part so as to close the side surface of the axial mixer without contact with it, and so that a gap is formed between the support element and the side surface of the axial mixer and between the support element and the lower surface of the axial mixer;

an outlet for draining the solution in the main body;

a protective element covering the side surface of the axial mixer without contact with it and forming a first flow channel between the protective element and the side surface of the axial mixer inside the protruding part;

first cooling means located inside the main body;

a circulation inlet channel located on the side surface of the protruding part so as to be on the side opposite the protruding part and to allow the flow of the cooled polymerization solution in it;

a feed input channel connected to the protruding portion, and

a flow channel determining element located between the supporting element and the protective element so as to cover the lateral surface of the axial mixer, and so as to fix the supporting element and the protective element determining the flow channel, the element forming the second flow channel between the lateral surface of the axial mixer and the determining flow channel element, and a third flow channel for connecting the second flow channel to the input channel of the source material;

moreover, from the first to the third flow channels constitute a continuous flow channel,

the highest end of the first flow channel is open inside the protruding part; and

the gap, part of the first flow channel, with the exception of the highest end, the second flow channel and the third flow channel are isolated from the inner zone of the protruding part.

The production apparatus discussed above is arranged in such a way that the starting material and the polymerization solution circulating under the action of the circulating cooling means are supplied to the protruding part. From first to third, the flow channels constitute a continuous flow channel. In addition, the highest end of the first flow channel is open inside the protruding part, the gap, part of the first flow channel, with the exception of its highest end, the second flow channel and the third flow channel are isolated from the inner zone of the protruding part, thus constituting an independent space in protruding part. Accordingly, the source material, newly introduced into the protruding part, passes through the input channel of the source material, the third flow channel, the second flow channel and the first flow channel and finally comes from the highest point of the first flow channel into the polymerization tank.

In general, the monomer, as the starting material of the polymer resin, and other starting materials are maintained at a low temperature so that they do not polymerize inside the container for storing the monomer, inside the adjusting tank for the introduced starting material and inside the line at any point up to the polymerization tank . The protective element and the element defining the flow channel prevent this low-temperature starting material from contacting the polymerization solution located in the protruding part when it flows from the first flow channel into the third flow channel, and the starting material itself is in direct contact with the axial mixer. Therefore, if there is no such protective element and there is no element determining the flow channel, as mentioned in the above embodiment, the starting material and the polymerization solution that circulates under the action of the second cooling means are directly mixed with each other immediately after being introduced into the protruding part. Consequently, a portion of the polymerization solution arises inside the protruding part, which in composition and temperature differs significantly from the polymerization solution inside the main body. In contrast, in the production apparatus of the above embodiment, it is possible to simultaneously and evenly mix the low-temperature starting material newly introduced into the protruding part, the polymerization solution inside the polymerization tank and the polymerization solution circulating under the action of the circulation cooling means in a small region of the bottom of the polymerization tank. As a result, it is possible to narrow the distribution of the polymer resin in composition and temperature.

In addition, the source material entering the protruding part is heated by the heat of friction generated by the rotation of the axial mixer on the support element, the heat from the polymerization solution circulating inside the second cooling means through the protective element, and the heat coming from the inside of the polymerization containers through a mixing device. Therefore, the starting material is at a certain level of high temperature at the time it drains from the highest end of the first flow channel into the polymerization tank. Accordingly, the temperature difference between the starting material flowing down from the uppermost end of the first flow channel and the polymerization solution becomes small. Thus, it is possible to even more evenly mix and mix the starting material and the polymerization solution. In addition, heat from the support member can be removed by this low temperature starting material. Therefore, it is possible to prevent overheating of the support element, shortening its service life, and the beginning of the polymerization reaction near this element.

The protective element is designed to be on the opposite side from the circulation inlet channel when the polymerization solution, passing through the second cooling means, enters the protruding part. Accordingly, it is possible to prevent lateral displacement of the axial mixer due to the liquid pressure of the circulating polymerization solution that occurs when the solution is introduced from the protruding part.

As discussed above, it is possible to cause a uniform polymerization reaction within the polymerization tank. Thus, it is possible to obtain a polymer resin having a uniform composition in a stable manner over a long period of time.

In the present description, the phrase "starting material" refers to a liquid material containing a monomer as a starting material of a polymer resin, a solvent, a molecular weight regulator, a polymerization initiator, if necessary, and the like, and re-introduced into the polymerization vessel through the input channel source material.

The phrase "polymerization solution" refers to a mixture of liquid components from those that are in the polymerization vessel, which formed a polymer resin, a monomer as a starting material of a polymer resin, a solvent, a molecular weight regulator, a polymerization initiator, if necessary, etc. .

The phrase "inside the protruding part" refers to the space, among those that are in the protruding part, surrounded by the outer surface of the protruding part, the side surface of the unclosed axial stirrer located on the support element, the protective element and the element defining the flow channel, the inner side wall protruding parts (excluding the side wall of the element defining the flow channel) and the element defining the flow channel. That is, the phrase "inside the protruding part" refers to the space from among those that are inside the protruding part, differing from the gap and from the first to third flow channels. The space represents, for example, part 30, indicated by the dashed line in figure 7.

The phrase “the uppermost end of the first flow channel” refers to a portion of those that belong to the first flow channel and are at the closest distance from the drive element.

The phrase "internal volume of the polymerization tank" refers to the volume of a portion of the space inside the polymerization tank. That is, the internal volume of the polymerization tank is expressed as “(the volume when the inner part of the polymerization tank is empty and not equipped with any means and parts) - (the volume occupied by the means and parts located inside the polymerization tank)”. Examples of the data "(means and parts located inside the polymerization tank") include a mixing device, a support element, a protruding part, a first cooling means and an element defining a flow channel. In addition, if the polymerization solution is loaded into the polymerization vessel, then the “internal volume of the polymerization vessel” corresponds to the volume of the polymerization solution.

In addition, the symbol "TL (tangent line)" denotes the boundary between the cylindrical part of the main body of the polymerization tank and the rounded parts of the corners of the head part that make up the upper part of the main body. This tangent line is, for example, the part indicated by the symbol "TL" in figure 6.

Brief Description of the Drawings

The figure 1 presents a diagram used to explain the production apparatus of the first embodiment of the invention;

figure 2 presents another diagram used to explain the production apparatus of the first embodiment of the invention;

3 is a diagram used to explain a cooling system constituting secondary cooling means of a first embodiment of the invention;

4 is a diagram used to explain one example of a protruding portion;

figure 5 presents another diagram used to explain one example of a protruding part;

6 is a diagram used to explain a production apparatus of a second embodiment of the invention;

figure 7 presents a diagram used to explain the internal structure of the protruding part inside the production apparatus.

In the drawings, the numbers have the following meanings: 1: cooling jacket; 2: mixing paddle; 3: suction pipe; 4a: tubular cooling coil; 4b: annular trunk pipeline; 5: safety washer; 6: circulation output channel; 7: circulation pump; 9: security element; 10, 10a, 10b: feed input channel 11: support element; 12: hole for draining the solution; 13: axial stirrer; 15: cooling medium; 18: channel circulating input; 19: circulation line 20: main body; 21: protruding part; 22: first flow channel; 23: second flow channel; 24: lower cover of the protruding part; 25: an element defining a flow channel; 26: static bearing; 27: cylindrical construction; 28: clearance; 29: the uppermost end of the first flow channel; 30: inner area of the protruding part; 31: third channel of the flow.

BEST MODE FOR CARRYING OUT THE INVENTION

Further, the present invention will be considered in relation to options for its implementation. These embodiments of the invention are presented to facilitate understanding of the essence of the present invention, and therefore, the present invention is not limited to the considered variants of its implementation. Accordingly, the present invention includes many alternatives to the embodiments described below.

In addition, in the material below, an explanation may be given using SAN as one example of a polymer resin. However, the polymer resin obtained using the production apparatus and the production method according to the present invention is not limited to SAN. The manufacturing apparatus and preparation method according to the present invention are also applicable to other polymer resins and copolymer resins in which the polymerization reaction is an exothermic reaction.

(First Embodiment)

Figures 1 and 2 illustrate one example of a manufacturing apparatus according to the present invention. Figure 1 is a side section of this production apparatus, and Figure 2 is a cross section along line A-A 'of the production apparatus shown in Figure 1 (Figure 2 represents only the main configuration of the production apparatus shown in Figure 1, and part of its construction is excluded from the figure In addition, the white area on a black background represents the part filled with the polymerization solution). This production apparatus is formed by a polymerization tank including a main body 20 and a protruding part 21 extending downward from the plane of the bottom of the main body. The lower portion of this protruding portion 21 constitutes the lower cover 24.

A drive element, not shown, is installed above the main body of this polymerization tank. In addition, the axial mixer 13 is connected to this drive element. This axial mixer 13 passes through the main body 20, being suspended in the air in its upper part, and passes from the drive element to the lower region of the protruding part 21. The blade 2 is welded to the side surface of this axial mixer 13. This axial mixer 13 and blade 2 comprise a rotating mixing device, so that the starting materials inside the polymerization vessel can be mixed and mixed by rotating the mixing device. As shown in FIG. 1, an additional mixing blade 17, including an auxiliary blade, can be installed in the lower part of this blade 2. By installing an additional mixing blade in this way, mixing efficiency can be improved.

In the lower cover 24 of the protruding part, a support element 11 is installed, which circumferentially covers the side surface of the axial mixer 13 without contact with it. This support element 11 is adapted to install the axial mixer 13 under control in order to prevent its excessive vibrations due to rotation. In addition, a gap 28 (shown in figure 4) is formed between the supporting element 11 and the side surface of the axial mixer 13 and between the supporting element 11 and the lower surface of the axial mixer 13.

In the upper part of this main body 20 there is a hole 12 for draining the solution, so that the polymerization solution can be discharged.

Inside the protruding part 21 is a protective element 9, which circumferentially covers the lateral surface of the axial mixer 13 without contact with it. In addition, the part of the space between the protective element 9 and the side surface of the axial mixer 13 forms the first flow channel.

Inside the main body of the polymerization tank there is a suction pipe 3, a tubular cooling coil 4a and an annular main pipe 4b to which a tubular cooling coil 4a is connected, so that the heat of polymerization can be removed. The suction pipe 3, the tubular cooling coil 4a and the annular main pipe 4b constitute the first cooling means.

This suction pipe 3 is, as shown in figures 1 and 2, a hollow cylindrical pipe. The cooling medium 15 is introduced into the lower part of the suction pipe 3, flows inside it, and then leaves through the other lower zone. Thus, the cooling medium 15 circulates through the suction pipe. In addition, the paddle of the mixing device is located inside this suction pipe, so that it is surrounded by a suction pipe. The upward flow of the polymerization solution occurs in the region inside the pipe, and the downward flow of the polymerization solution occurs in the region outside the pipe due to the rotation of the mixing device, effectively raising the rotating flow inside the polymerization tank.

In figure 1, the tubular cooling coil 4a is located so that four times surrounds the outer side of the suction pipe 3. The cooling medium 15 is supplied from the lower parts of the annular main pipelines 4b located in the upper and lower parts of the main body, and passes through each elbow of the tubular cooling coil 4a and then discharged from opposite lower zones of the annular trunk pipelines 4b. Thus, the cooling medium 15 circulates through the tubular cooling coil.

As the cooling medium 15 used in the suction pipe 3 and the tubular cooling coil 4, a well-known medium including Therminol 55 and Therminol 59 manufactured by Soluta Inc., Dowtherm Q and Dowtherm MX manufactured by The Dow Chemical Company, and NeoSK-Oi1 can be used 330 and NeoSK-Oi1 1400 manufactured by Soken Tecnikx Co., Ltd.

As the first cooling means, the suction pipe 3 can be entirely used. In addition, when a tubular cooling coil 4a is used, one or more circular groups of tubular cooling coils are set for a pair of annular main pipes, and there is no limit for a specific number of annular main pipes. In addition, in the present embodiment, two pairs of annular main pipes and a double circular group of tubular cooling coils for each pair of annular main pipes are installed.

In addition, the first cooling means is not limited to the suction pipe 3 and the tubular cooling coil 4a. Alternatively, you can use a well-known cooler of such a length that can provide stable cooling of the polymerization solution for a long period of time.

On the side surface of the protruding part 21 is located the channel 18 of the circulation input from the opposite side from the protective element 9. In addition, the circulation line 19 is connected from the channel 6 of the circulation outlet of the main body 20 to the channel 18 of the circulation input. The second cooling means 8 and the circulation pump 7 are connected to this circulation line 19 at midpoints. The channel 18 of the circulation inlet, the second cooling means 8, the circulation pump 7, the channel 6 of the circulation outlet located on the main body 20, and the circulation line 19 for connecting these components constitute the means of circulation cooling. During the operation of the circulation pump 7, the polymerization solution discharged along the circulation channel 6 of the main body 20 returns to the protruding part 21 along the circulation input channel 18 after cooling by the second cooling means 8.

There is no particular restriction on this second cooling means as long as the polymerization solution can be continuously cooled by the flowing solution. As a second cooling means, it is preferable to use a heat exchanger such as that shown in FIG. 3 from among other heat exchangers capable of being cleaned along the inner wall of the tube due to the reciprocating movement of the coil spring.

The heat exchanger shown in figure 3 includes a jacket 33 and a tube 38 located therein. This tube 38 is connected to the circulation line 19 by an inlet 34 and an outlet 35, so that the polymerization solution flows through this tube when the circulation pump 7 is turned on. That is, the polymerization solution enters through the inlet channel 34, passes through the tube 38, and then exits through the outlet channel 35 In addition, the heat exchanger is designed so that the cooling medium is introduced through the inlet channel 36 and discharged through the outlet channel 37. The cooling medium flowing inside the jacket 33 and the polymerization solution flowing inside the tube 38, p Cereal apart tubular sheet, providing heat removal of the polymerization solution by heat transfer through the tube.

In addition, a coil spring 39, which reciprocates along the inner wall of the tube 38, is inserted into it and attached to the panel 40. This panel 40 is connected to the shaft 41 to provide external reciprocating motion continuously or intermittently by means of a drive element 42 reciprocating motion.

When the polymerization solution is circulated under the influence of the circulation coolant for an extended period of time, the solid may adhere to the inner wall of the tubes within which the polymerization solution flows. Even if a solid adhered to the inner wall of the tube, as described above, the use of this heat exchanger allows the solid to be periodically scraped off with a coil spring. As a result of this, it is possible to cool the polymerization solution stably and continuously.

The figure 3 shows the case when the coil spring performs a reciprocating motion. However, the movement of the coil spring is not limited to this movement. Alternatively, the heat exchanger may be designed such that the shaft 31 and the reciprocating drive element 32 are mounted for each coil spring, and each coil spring can rotate independently. In addition, as the cooling medium flows inside the jacket 33, one of the above heat transfer media mentioned above can be used.

The third cooling means 1 is installed so as to close the outer wall of the polymerization tank. As this third cooling means 1, it is possible to use, for example, a cooling jacket.

The feed channel 10 is connected to the protruding portion 21, so that the feed is initially supplied to the polymerization tank. In addition, this monomer, as the starting material of the polymer resin and other starting materials, is usually kept at a low temperature to prevent polymerization inside the storage vessel or inside the pipeline at any point up to the polymerisation vessel. The use of this low-temperature starting material increases the ratio at which the heat of polymerization can be removed using the appropriate heat of the starting materials. Thus, the load on the first cooling means, the second cooling means and the third cooling means can be reduced.

Between the support element 11 and the protective element 9, a second flow channel is formed so as to circumferentially close the lateral surface of the axial mixer 13 with an element 25 defining the flow channel. In addition, this element 25, which defines the flow channel, connects the support element 11, the protective element 9 and the channel 10 for inputting the source material. The flow channel defining element 25 forms a third flow channel 31 for connecting the second flow channel to a channel for inputting raw material.

This flow channel determining element 25 must be installed at least between the supporting element 11 and the protective element 9, so as to close the axial mixer 13. However, the flow channel determining element 25 can exist not only in the area between the supporting element 11 and the protective element 9, but also in the area located slightly above this area (in the direction of the drive element). In this case, a part of the channel determining the flow element 25 (the part located above the region between the supporting element 11 and the protective element 9) covers the bottom of the protective element 9, as shown, for example, in figures 4 and 5.

Data from the first to third flow channels form a continuous flow channel. In addition, the uppermost end 29 of the first flow channel is open inside the protruding part, and the gap, a part of the first flow channel different from its uppermost end, the second flow channel and the third flow channel are isolated from the inner zone of the protruding part. Accordingly, the gap, a part of the first flow channel, different from its uppermost end, the second flow channel and the third flow channel limit a separate space formed entirely by these elements in the protruding part of the reactor. Therefore, the section located from the input channel 10 of the source material to the first flow channel (channel 10 of the input material - the third flow channel 31 - the second flow channel 23 - the first flow channel 21) is designed to prevent leakage of the introduced low-temperature material from any point along the section and contact with the polymerization solution inside the polymerization tank. In addition, this channel 10 for inputting the starting material is connected to the first flow channel through the third and second flow channels. Therefore, the low-temperature source material entering from the channel 10 for inputting the source material passes through the third channel of the stream 31, the second channel of the stream 23 and the first channel of the stream 21, without contacting the polymerization solution. Finally, the source material flows from the highest end (the space between the highest end of the protective element and the side surface of the axial mixer) 29 of the first flow channel 21 to a place located inside the protruding part near its upper zone.

In this way, the starting material, first introduced into the polymerization tank, is sent to the mixing device located in the main body, and is quickly and uniformly mixed with the polymerization solution inside the polymerization tank. After that, as shown by the arrows in Figure 1, the polymerization solution, under the action of the rotational movement of the mixing device, begins to rise into the region of the main body, closer to its center than the suction pipe, descends to the area located further from the center than the suction pipe, and returns to bottom of the main body. In this way, the starting material is circulated and mixed inside the main body. The polymerization reaction proceeds while the polymerization solution is circulated and mixed, as discussed above, and thus a polymer resin is formed.

In addition, part of the polymerization solution containing the polymer resin thus formed is discharged from the channel 12 for draining the solution located in the upper part of the main body. Then, the unreacted monomer, solvent, and polymer resin are separated from the withdrawn polymerization solution using a film evaporator, an extruder, such as a tube-type tube heat exchanger with a jacket, as described in Japanese Patent Publication No. 48-297997, a gas-liquid separator (none of which are shown in figure 1), etc. And then the polymer resin is granulated into the product. After the unreacted monomer and solvent are separated, the starting material is further introduced, so that the mixture thus obtained has a predetermined composition, thus, the unreacted monomer and the solvent are again used as starting materials.

Figure 4 illustrates one example of a protruding part, a protective element and flow channels from the first to third production apparatus. As shown in figure 4, the support element 11 is located on the bottom cover 24 of the protruding part. In addition, the axial mixer 13 is regulated by the support element 11, so as not to move horizontally. The upper and lower parts of this support element 11 respectively consist of a static bearing 26 and a cylindrical structure 27 for supporting the static bearing. Both the static bearing and the cylindrical structure are both arranged so as to circumferentially close the lateral surface of the axial stirrer 13, preferably without contact with it. The design of the support member 11 is not limited to the structures illustrated in FIG. 4. Alternatively, the static bearing 26 and the cylindrical structure 27 may have a structure in which the static bearing and the cylindrical structure are fixed to the element defining the flow channel, a key and a keyway so that don't spin.

Although under the control of the static bearing 26, so as not to deviate in a horizontal position, as discussed above, the axial mixer 13 is connected to the drive element, being suspended in the air. Accordingly, there is a space between the axial stirrer 13 and the lower cover 24 of the protruding part. Thus, the manufacturing apparatus is designed so that appropriate spaces are formed between the side surface of the axial mixer 13 and the static bearing 26 and between the side surface of the axial mixer 13 and the cylindrical structure 27. That is, a gap 28 is formed between the side surface of the axial mixer 13 and the supporting member 11 and between the bottom surface of the axial stirrer 13 and the support element 11. Preferably, the production apparatus is designed so that the gap is usually 0.1 mm or more, but not more than 1 mm, between the lateral surface of the axial mixer 13 and the supporting element 11, so that the axial mixer can rotate freely. In addition, by obtaining a clearance in this way, it is possible to prevent the axial stirrer 13 from contacting the support element 11 and the protruding portion lower cover 24, even if the axial stirrer expands due to heating inside the polymerization tank.

This static bearing 26 is made of a softer material than the material of the axial mixer 13, and therefore can be scratched when the axial mixer 13 is rotated. Anticipating this option, the production apparatus can be designed so that the protruding part segment is removable, so that, if necessary, it is possible static bearing replacement 26.

In addition, in the area of the axial stirrer 13, a protective cap, although not shown in figure 4, opposite the static bearing 26, can be installed to protect the axial stirrer 13. By installing such a protective cap, damage to the axial stirrer 13 can be prevented if between the static bearing 26 and the axial mixer 13 will get foreign material.

A protective element 9 is installed inside the protruding portion 21 to circumferentially close the lateral surface of the axial mixer 13. Since this protective element 9 and the lateral surface of the axial mixer 13 are spaced apart from each other, a spatial zone is formed between the protective element 9 and a lateral surface of the axial mixer 13. This spatial zone serves as the first flow channel 22.

As the material for the protective element, for example, stainless steel can be used. The wall thickness of the protective element is determined by the strength necessary to prevent the bending of the protective element under the pressure of the liquid of the circulating polymerization solution. Accordingly, the wall thickness can be determined accordingly, by the flow rate through the channel of the circulation input. This protective element can be designed so that at least part of the lower zone of the protective element is threaded in such a direction as to prevent the protective element from being unscrewed by the rotation force of the solution arising from the rotation of the axial mixer, and then fixed to the element defining flow channel.

In the present embodiment, an example is shown in which one circulation pump, one cooler, one of the circulation output channels and one circulation input channel are respectively grouped into one group. However, each of the groups of circulation pumps, coolers, channels of the circulation output and channels of the circulation input is not limited to one group, but can be installed in two or more groups. Channels for introducing source material can also be installed in two or more pairs. In this case, the element defining the flow channel and the third flow channel are grouped so as to be consistent with the number of channels for inputting the source material and their location.

In addition, as a modified example of the embodiment of the invention shown in FIG. 4, another input material passage 10b can be further installed below the protruding portion bottom cover, as shown in FIG. 5, so that the raw material can be introduced through this input channel 10b source material. The source material introduced through this channel 10b for introducing the source material into the lower zone of the protruding part passes through the gap 28 between the lower surface of the axial mixer 13 and the bottom cover 24 through the gap 28 between the lateral surface of the axial mixer 13 and the supporting element 11 through the second channel current 23 - along the first channel of the current 22, in this order. Then, the source material passes through the first channel of the stream 22 after connecting with the source material introduced along line 10a into this second channel of the stream 23, and merges from its highest end 29 into the lower zone of the protruding part. With such a configuration as discussed above, it is possible to further enhance the cooling effect of the support member.

Here, the raw materials introduced through the feed channels 10a and 10b comprise a monomer as a polymer resin starting material, a solvent, a molecular weight regulator, a polymerization initiator, if necessary, and the like. In addition, the starting materials are maintained at a low temperature so that the polymerization reaction does not proceed inside the adjusting tank for the introduced starting material and inside the pipeline at any point up to the polymerization tank.

In this manufacturing apparatus of the present embodiment, as shown in Figures 4 and 5, the feed introduced through the feed channels 10, 10a, 10b passes through a third flow channel 31, a second flow channel 23, and a first flow channel 22 according to the above configurations. In addition, the gap, parts of the first flow channel that differ from its highest end, the second flow channel and the third flow channel are isolated from the inner zone of the protruding part and these elements constitute an independent, characteristic space in the protruding part. In addition, only the highest end 29 of the first flow channel is open to the inner zone of the protruding part. Accordingly, the low-temperature starting material introduced into the polymerization vessel is protected by the protruding element 25 of the protruding part and the protective element 9 from contact with the polymerization solution located in the protruding part 21, while flowing through the third flow channel 31, the second flow channel 23 and the first channel 22 and is in direct contact with the axial mixer 13. This means that the low-temperature starting material is in the area near the support element 11, thereby providing about heat transfer from the support member 11. Therefore, it is possible to prevent the polymerization of the monomer in the vicinity of this region. In addition, with the low-temperature starting material, the frictional heat generated by the rotation of the axial mixer 13 between the starting material and the static bearing 26 can be removed. Thus, it is possible to reduce the friction in the static bearing 26 and extend its service life.

The source material, passing through the flow channels from the first to the third, is heated by the heat of friction generated by the rotation of the axial stirrer 13 between the source material and the support element 11, heat coming from the polymerization solution circulating inside the second cooling means through the protective element, and heat transferred from the inner zone of the polymerization tank with stirring. Therefore, the starting material has a high temperature of a certain level at the time of runoff from the highest end 29 of the first flow channel 22 into the polymerization tank. Accordingly, the temperature difference between the starting material flowing down from the highest point 29 of the first flow channel 22 and the polymerization solution becomes small. Thus, it is possible to even more evenly mix and mix the starting material and the polymerization solution.

In addition, the protective element is installed so as to be opposite to the channel of the circulation inlet, which is the element where the polymerization solution, passing through the second cooling means, enters the protruding part. Therefore, it is possible to prevent horizontal deviation of the axial mixer due to the liquid pressure of the circulating polymerization solution, which occurs when the solution is introduced into the protruding part. Therefore, you can increase the speed of circulation by installing a protective element.

As discussed above, in the present embodiment, it is possible to simultaneously and evenly mix the low-temperature starting material newly introduced into the protruding portion, the polymerization solution inside the polymerization vessel and the polymerization solution circulating under the influence of the circulation cooling means, in a small area at the bottom of the polymerization vessel. As a result of this, the distribution of the polymer resin in composition and temperature can be narrowed.

In contrast, if there is no such protective element as described in the present embodiment, the polymerization solution, passing through the second cooling medium, and the starting material are mixed immediately after entering the protruding part. Consequently, a portion of the polymerization solution arises inside the protruding part, the composition and temperature of which differs significantly from the composition and temperature of the polymerization solution inside the main body. In addition, a high temperature polymerization solution falls on the support element, and this element becomes, therefore, even hotter due to the heat of thorns, and as a result a polymer resin is formed, which in composition is significantly different from the polymer resin inside the main body. Moreover, the service life of a static bearing is shortened. If the circulation speed of the polymerization solution under the action of the circulating coolant is increased in order to improve the cooling efficiency of the polymerization solution, the polymerization solution will be pushed out of the circulation inlet channel 18 into the protruding part 21 under high liquid pressure. Accordingly, the axial mixer 13 will tend to deviate in the horizontal plane under the action of this high pressure fluid.

The temperature of the polymerization solution inside the polymerization vessel can be set according to the type of resin being produced. For example, as an example, a case is considered when a resin based on a styrene-acrylonitrile copolymer (SAN), which is a copolymer resin, is obtained as a polymer resin. In this case, the temperature is preferably 120 ° C or higher, but not more than 190 ° C, and more preferably 125 ° C or higher, but not more than 170 ° C, if the initiator is not used. If the temperature of the polymerization solution inside the polymerization tank is maintained in these ranges, then it is possible to effectively carry out the polymerization reaction to obtain SAN.

The temperature of the polymerization solution returned by the circulating coolant to the protruding part is preferably lower than the temperature of the polymerization solution inside the polymerization tank by 2 ° C or higher, but not more than 10 ° C, more preferably 2 ° C or higher , but not more than 5 ° C, immediately before returning the polymerization solution back to the protruding part. If the temperature of the polymerization solution returned to the protruding portion is within the indicated limits, then the heat of polymerization can be effectively removed by reducing the temperature difference between the returned polymerization solution and the polymerization solution inside the polymerization tank. In addition, it is preferable that a cooling medium having a temperature of 5 ° C or more lower, but not more than 40 ° C than the polymerization temperature, flow through this second cooling medium.

When introducing raw materials from two input channels 10a and 10b of input material, these raw materials introduced through the channels may be the same or may differ from each other. For example, when producing a resin based on a styrene-acrylonitrile (SAN) copolymer as a polymer resin, styrene can be introduced from one input channel of the starting material, and acrylonitrile can be introduced from another input channel of the starting material.

The first cooling means preferably includes a suction pipe, which is installed so as to surround the blade of the mixing device, and inside which a cooling medium flows, a tubular cooling coil installed between the suction pipe and the inner wall of the main body, and annular main pipes installed in the upper and lower areas of the polymerization tank and designed to ensure the flow of the cooling medium through the tubular cooling coil. As the third cooling medium, it is preferable to use a cooling jacket. In addition, A / B is preferably 6 m ² / m ³ or more, but not higher than 25 m ² / m ³ , where A (m ² ) represents "the sum of the areas of the outer surfaces of the suction pipe, tubular cooling coil and ring main pipelines inside the main the casing and the outer wall area of the main casing coated with a cooling jacket ", and B (m ³ ) represents the" internal volume of the polymerization tank ". In addition, the phrase "the area of the outer surfaces of the suction pipe, tubular cooling coil and annular main pipelines" refers to the surface areas of the elements of the outer surfaces of the suction pipe, tubular cooling coil and annular main pipelines that exist inside the polymerization tank.

If A / B is 6 m ² / m ³ or more, the cooling efficiency increases, and therefore, it is possible to ensure uniform distribution of the temperature of the polymerization solution, and therefore the composition of the polymer resin. In addition, setting the A / B to a value of 25 m ² / m ³ or less can prevent a decrease in the gap between the cooling tubes, causing an uneven flow of the polymerization solution, or prevent an increase in the mixing power, causing an increase in the heat of mixing. As a result, it is possible to achieve excellent cooling performance and reduce costs.

The polymerization apparatus preferably includes the suction pipe described above, a tubular cooling coil and annular pipelines as the first cooling means, and preferably comprises the use of a cooling jacket as the third cooling means. In addition, as a second means of cooling, it is preferable to use a cooler including a jacket in which the cooling medium flows, a pipe connected to the circulation line and installed inside the shell, and a coil spring installed inside the cooler pipe and capable of at least one return - translational motion and rotational motion. In this case, A / C is preferably 0.2 or more, but not more than 1.0, where A (m ² ) represents “the sum of the areas of the outer surfaces of the suction pipe, the tubular cooling coil and the annular main pipe inside the main body, and the area of the outer the walls of the main body, covered with a cooling jacket "and C (m ² ) represents" the area of the inner surface of the cooler tube ". In addition, the phrase “the outer surface of the suction pipe, the tubular cooling coil and the annular main pipe” refers to the surface area of the elements of the outer surfaces of the suction pipe, the tubular cooling coil and the annular main pipe that exists inside the polymerization tank.

If A / C is less than 0.2, the proportion of heat removed by the second cooling means increases. Therefore, if the circulation volume does not increase, the temperature of the polymerization solution circulating through the second cooling means becomes much lower than the internal temperature of the polymerization tank, thereby destroying the uniformity of the resin composition inside the polymerization tank. In addition, if the circulation volume increases, there is a need to increase the strength of the protective element and the main body of the apparatus in order to balance the increase in mixing power or the increase in liquid pressure in the second cooling means. This may worsen the technical and economic performance of the apparatus as a whole.

On the other hand, if A / C exceeds 1.0, the proportion of heat removed by the first cooling means and the third cooling means becomes extremely high, compared with the fraction of heat removed by the second cooling means. As a result, the cooling efficiency of the first and third cooling means may deteriorate due to the formation of a solid substance that adheres to the surfaces of these means and shortens the duration of continuous operation. Therefore, it may not be possible to continue the long work.

In addition, if the distance from the fixed position of the protective element to the channel of the circulation input is too large, the protective element tends to bend under the action of the fluid pressure of the circulating solution. Therefore, it is preferable to reduce the distance from the fixed end of the protective element to the point of intersection of the center line of the circulation inlet channel and the protective element (distance from the fixed end of the protective element to the part of the protective element that receives the fluid pressure). In addition, the highest end of the protective element is preferably located above the highest end of the inner wall of the circulation inlet channel and below the lowest end of the lower surface of the main body. When the highest end of the protective element is located above the highest end of the inner wall of the circulation inlet channel, the protective element is positioned so that it is opposite to the circulation inlet channel. Accordingly, it is possible to prevent horizontal deviation of the axial mixer under the action of the liquid pressure of the polymerization solution entering through the circulation inlet channel. In addition, if the highest end of the protective element is located below the surface of the bottom of the main body, the source material passes through the highest end of the first flow channel and enters the area near the upper zone of the protruding part inside the polymerization tank, to first mix with the polymerization solution in this area. The blade and the auxiliary mixing blade are installed inside a narrow space in this area, so that at a given time, the starting material and the polymerization solution are mixed and mixed at a high shear rate. Therefore, it is possible to more efficiently mix the starting material and the polymerization solution with each other and carry out the polymerization reaction.

If the inner diameter of the circulation inlet channel is taken to be D _N , then the highest end of the security element will preferably be located at a distance of 0.5 D _N or higher than the highest end of the inner wall of the circulation inlet channel. If the highest end of the protective element is located at a given height, the fluid pressure on the axial mixer is reliably reduced. In addition, it is possible to provide effective mixing, mixing of the starting material and the polymerization solution and the course of the polymerization reaction.

(Second Embodiment)

The present embodiment relates to a decompression element for terminating a polymerization reaction within a polymerization vessel. The figure 6 presents one example of this production apparatus. In the present embodiment, unlike the first embodiment, the production apparatus includes a safety washer 5 in the upper zone of the main body 20 as a decompression element opening to reduce the pressure inside the polymerization tank when the internal pressure in the polymerization tank is equal to or exceeds a predetermined pressure. The inlet channel and a decompression device, such as a remote control valve, can be installed as a decompression element instead of a safety washer 5. In addition, the circulation line 19 is connected to the side surface of the main body 20, and the height between the tangent line (TL) of the main body 20 and the highest end of the inner wall of the circulation line 19 is 0.2 D or more, but not more than 0.5 D, provided that the inner diameter of the cylindrical part of the main body 20 is “D”.

The safety washer 5 is installed in this way and is additionally connected to a container (not shown in FIG. 6), in which the pressure is kept lower than the pressure in the polymerization tank. Accordingly, if the polymerization reaction inside the polymerization vessel goes out of control, and the internal pressure in the polymerization vessel becomes excessively high, the safety washer 5 is destroyed and releases the inside of the polymerization vessel. Thus, it is possible to reduce the pressure inside the polymerization tank. As a result, an excessive increase in internal pressure and temperature inside the polymerization vessel and destruction of the polymerization vessel can be prevented.

In addition, if the safety washer 5 is destroyed, as described above, so that the pressure inside the polymerization tank decreases, part of the polymerization solution evaporates and leaves the system, thereby increasing the space inside the main body 20. If at this point in time the channel of the circulation outlet 6 is connected to the internal surface of the main body 20 in its highest position, the circulation pump sucks gas from the upper part of the main body 20 and goes into idle mode, probably this way th may not work properly.

On the other hand, if the channel of the circulation terminal 6 is connected to the side surface of the main body 20 in its lower position, the circulation pump causes the polymerization solution to move near the bottom of the main body 20, although the circulation pump does not go into idle mode. This polymerization solution near the bottom of the main body 20 is already cooled by a tubular cooling coil and, therefore, is at a low temperature. Accordingly, the relatively low temperature polymerization solution is further cooled by the second cooling means, thereby causing the polymerization solution to return to the polymerization tank even with an even lower temperature. Therefore, the temperature distribution of the polymerization solution inside the polymerization tank expands. As a result of this, the composition of the polymer resin formed inside the polymerization tank becomes heterogeneous.

In contrast, in the present embodiment, the height between the TL of the main body 20 and the uppermost end of the inner wall of the circulation output channel 6 is 0.2 D or more, but not more than 0.5 D. Moreover, the circulation output channel 6 is connected with the side surface of the main body 20 at an appropriate height.

Therefore, even if the polymerization reaction goes out of control and the safety washer 5 is destroyed, the circulation pump 7 does not go into idle mode. In addition, it is possible to approximate the temperature of the polymerization solution at the outlet of the cooler circulating under the action of the circulation cooling means, as close as possible to the internal temperature in the polymerization tank. Therefore, it is possible to narrow the temperature distribution of the polymerization solution inside the polymerization tank and increase the uniformity of the composition of the polymer resin.

A level switch can be installed on the inner wall of the polymerization tank so that it can be determined at what level the polymerization solution is at the time of the destruction of the safety washer 5.

(Third Embodiment)

A third embodiment of the invention is illustrated by an example in which a copolymer resin is used as the polymer resin. A distinctive feature of many copolymer resins is the high copolymerization reaction rate and high heat of reaction. Thus, copolymer-based resins differ in that the internal temperature in the polymerization tank tends to increase, and the temperature distribution inside the polymerization tank becomes inhomogeneous. Accordingly, when using the production apparatus according to the present invention, it is possible to remove the polymerization heat generated during the copolymerization reaction inside the polymerization vessel and to uniformly control the internal temperature in the polymerization vessel within the desired temperature range. In addition, by introducing a low temperature copolymer-based resin starting material into the protruding portion, it is possible to maintain a low temperature at the support member and the axial mixer. As a result of this, it is possible to continuously and uniformly obtain a copolymer-based resin having a uniform composition. In addition, it is possible to reduce the friction of the static bearing, and it is also possible to prevent the polymerization of the monomer on and near the support member.

As this copolymer resin, it is preferable to obtain a styrene-acrylonitrile (SAN) copolymer resin. The styrene-acrylonitrile (SAN) copolymer resin, among other copolymer resins, is characterized in that the reaction rate is high, the heat of polymerization is high and transparency is impaired if the resin is uneven in composition. Therefore, the use of the production apparatus according to the present invention allows for efficient removal of the reaction heat generated by the copolymerization reaction. Thus, it is possible to effectively and stably control the internal temperature in the polymerization vessel within the desired temperature range. As a result, it is possible to obtain a SAN having a uniform composition and excellent transparency, as well as preventing friction and the like. phenomena of the supporting element.

Paragraphs (1) to (4) below list the conditions that are preferred when a styrene-acrylonitrile (SAN) copolymer resin is obtained as the polymer resin.

(1) The proportion of the acrylonitrile component of the resulting SAN resin increases as the content of acrylonitrile in the feed increases through the feed passage 10. Therefore, the proportion of the acrylonitrile component in the resulting SAN resin is preferably 15% by mass or higher, but not more than 35% by mass, and the styrene content is preferably 65% by mass or higher, but not more than 85% by mass. Accordingly, it is preferable that the mass ratio "acrylonitrile / (acrylonitrile + styrene)" in the starting material is 0.15 or higher, but not more than 0.5, so that the SAN has the composition as discussed above.

(2) In addition, the solvent content in the feed introduced through the feed inlet 10 is preferably 5% by mass or higher, but not more than 30% by mass. The solvent is used to reduce the mixing power and control the rate of polymerization reaction. When the solvent content in the source material lies within these limits, it is possible to obtain SAN stably and with high performance. A type of solvent may be an aromatic hydrocarbon compound such as benzene, toluene and ethylbenzene, etc.

(3) In addition, as a molecular weight regulator, a sulfur-containing compound such as tertiary dodecyl mercaptan and the like can be included in the composition of the starting material introduced through the input channel 10 of the starting material. at a concentration of 100 million hours or higher, but not more than 8000 million hours Organic peroxide, for example, benzoyl peroxide, lauryl peroxide, acetyl peroxide or the like, may be contained in the starting material as an initiator in each case individually.

(4) In the absence of an initiator, the polymerization conditions include a temperature of preferably 120 ° C. or higher, but not more than 170 ° C., and a residence time is preferably 1 hour or more, but not more than 3 hours. In the case of using an initiator, the polymerization conditions include a temperature of preferably 70 ° C or higher, but not more than 125 ° C and a residence time of preferably 1 hour or more, but not more than 3 hours.

(Fourth Embodiment)

This embodiment of the invention relates to a production method using an apparatus for producing a SAN. The present embodiment includes the following steps:

(1) a step for preparing the polymerization vessel loaded with the polymerization solution;

(2) the step of introducing the source material through the input channel of the source material into the third flow channel, the second flow channel and the first flow channel in the protruding part;

(3) a polymerization reaction step in which a polymer resin is formed by mixing the starting material with the polymerization solution under the action of rotation of the mixing device;

(4) a step for cooling the polymerization solution inside the polymerization vessel by the first and third cooling means;

(5) the step of withdrawing the polymerization solution from the main body using a circulation pump, cooling the polymerization solution with a second cooling means, and then returning the polymerization solution to the protruding part through the circulation inlet channel; and

(6) a step for discharging the polymerization solution along the channel for discharging the solution and then separating the polymer resin from the polymerization solution.

In the above production method, steps (1) to (6) may optionally be carried out sequentially. Alternatively, some or all of the steps may be carried out simultaneously.

Here, the volumetric flow rate of the polymerization solution circulating inside the main body is preferably 50 times or more, but not more than 300 times, and more preferably 80 times or more, but not more than 200 times, the volumetric flow rate of the source material introduced through the input channel of the source material.

Here, "the volumetric flow rate of the polymerization solution circulating inside the main body" can be measured using the indicator particle method. That is, a syrup-like solution or silicone oil having the same viscosity as the viscosity of the polymerization solution is placed in an acrylic thermoplastic container having the same design and size as the polymerization container, and mixed using a mixing device after the introduction of a new starting material is completed and draining the polymerization solution. Then indicator particles, such as spherical particles with a diameter of about 2 mm to 3 mm, from colored vinyl chloride resin, polystyrene resin or ABS resin, the density difference of which and the polymerization solution is not more than about 5%, are placed in the polymerization tank. Then determine how many times per unit time (per hour) indicator particles circulate inside the polymerization tank. Then calculate the "bulk velocity of the polymerization solution circulating inside the main body" based on the number of circulations of indicator particles inside the polymerization tank.

For example, if indicator particles circulate inside the polymerization tank “A” once an hour and the volume of the polymerization solution inside the polymerization tank is “V” (m ³ ), then the “volumetric flow rate of the polymerization solution circulating inside the main body” is A × M (m ³ / h). Accordingly, using the formula A × V / Q, it is possible to calculate how many times the volume of the polymerization solution circulating inside the polymerization tank is greater than the volumetric flow rate of the starting material introduced through the input channel of the starting material, assuming that the flow rate of the newly introduced starting material is Q (m ³ / h). Spherical indicator particles can be obtained by loading the starting resin, pigment, etc. into the extruder and granulating it by underwater cutting.

The viscosity of the polymerization solution can be determined, for example, by (a) evaluating the pressure loss on the discharge line from the circulation pump or on the outlet line of the polymerizing solution and calculating the viscosity using the Hagen-Poiseuille equation, or (b) installing a vibration type viscometer or the like. inside the polymerization tank or on the output line from it.

Heat transfer increases with increasing consumption of the polymerization solution passing through the second cooling means, and therefore, the temperature at the outlet of the polymerization solution also increases. Therefore, an excellent transparency polymer can be obtained. On the other hand, the power of the circulation pump increases and, therefore, if necessary, the power or strength of the scraping device increases, which leads to a deterioration in the technical and economic indicators of the production method. Accordingly, if the second cooling means consists of a cooler including the above jacket, pipe and coil spring, then the ratio (“volumetric flow rate of the polymerization solution flowing inside the tube of the second cooling means”) is preferably 0.2 m ³ / h / m ² or higher but not more than 0.5 m ³ / h / m ² . With the ratio "(volumetric flow rate of the polymerization solution flowing inside the tube of the second cooling means) / (area of the inner surface of the tube of the second cooling means)" lying inside the above interval, we can approximate the temperature at the outlet of the cooler of the polymerization solution circulating under the action of the circulation cooling means, as close as possible to the internal temperature of the polymerization tank. As a result, it is possible to narrow the temperature distribution of the polymerization solution inside the polymerization tank and make the polymer resin uniform in composition.

If the resin to be produced is a styrene-acrylonitrile (SAN) copolymer resin, the temperature of the starting material introduced through the input channel of the starting material into the protruding portion is preferably -5 ° C or higher, but not more than 20 ° C, more preferably 0 ° C or higher, but not higher than 10 ° C. This starting material may be pre-cooled using, for example, a cooling medium such as chilled water or saline. Since water often dissolves in acrylonitrile, which is the starting material, this water freezes on the inner wall of the cooling device if the temperature of the starting material is excessively low, thereby impairing the cooling ability of the cooling device. On the other hand, if the temperature of the starting material is excessively high, the starting material under the action of heat of friction between the support element and the axial mixer, heat coming from the polymerization solution circulating inside the second cooling means along the protruding part, and heat coming from the inside of the polymerization tank through a mixer, it can begin to copolymerize in any of the flow channels from the first to the third or in the gap or the like.

Examples of embodiment of the invention

(Example 1 embodiment of the invention)

SAN was obtained using the production apparatus shown in Figure 1. This production apparatus included a polymerization vessel including a main body 20 and a protruding part 21. Inside the main body 20, the production apparatus included a screw type mixing device, an axial mixing blade 17, a suction tube 3, a tubular a cooling coil 4a and an annular main pipe 4b to which a tubular cooling coil is attached. On the outer wall of the polymerization tank, the production apparatus included a cooling jacket 1. A part of the polymerization solution was discharged from the main body 20 by a circulation pump 7 and, after cooling in the cooler 8, was returned to the protruding part 21 from the opposite side from the protective element 9. This cooler 8 included a jacket inside which the cooling medium flowed, the tube that was located inside the jacket and inside which the polymerization solution flowed, and the coil spring installed inside the tube, so that providing scraping material adhered to the inner wall of the tube under the action of its reciprocating movement.

In addition, the production apparatus is designed in such a way that the source material is introduced into the protruding part 21 from the side of its side surface through the input channel 10 of the source material. The starting material was cooled in a heat exchanger to 20 ° C and continuously fed at a speed (F) of 2.06 m ³ / h. The composition of the starting material was selected so that the mass ratio of styrene, acrylonitrile, ethylbenzene and tertiary dodecyl mercaptan was 0.5421 / 0.3539 / 0.0995 / 0.0045. The flow rate (D) of the circulating polymerization solution was adjusted to 16 m ³ / h by selecting a gear pump for the circulating pump 7 and adjusting its speed.

In addition, the internal volume (B) of this polymerization tank was 2.67 m ³ , the total amount (A) of the areas of the outer surface of the suction pipe 3, the tubular cooling coil 4a and the annular main pipe 4b and the area of the outer wall of the main body 20 covered with a cooling jacket 1, was 40 m ² , and the inner surface area (C) of the tubular cooler 8 was 49.67 m ² . On the other hand, the volumetric flow rate (E) of the polymerization solution circulating inside the main body was set to 200 m ³ / h by adjusting the number of revolutions of the mixing device to 80 rpm.

The polymerization temperature was maintained at 144 ° C. by controlling the temperature of the cooling medium flowing through the suction pipe, the tubular cooling coil, the cooling jacket and the cooler jacket 8. The flow rate of this cooling medium was 90 m ³ / h. The polymerization temperature was measured by a thermometer inserted 200 mm inward from the outer wall of the main body in the middle of the upper and lower tangent lines of the main body of the polymerization tank.

The polymerization solution, continuously discharged through the nozzle 12 to drain the solution, installed in the upper part of the main body, was introduced into a tubular heat exchanger with a jacket and a gas-liquid separator described in Japanese Patent Publication No. 48-29797. Then, the unreacted monomer, solvent, and SAN were separated from this polymerization solution. At this point, the pressure in the gas-liquid separator was constantly maintained at 40 Torr, and the temperature of the heated medium flowing through the heat exchanger was controlled so that the temperature of the separated SAN was 220 ° C. After that, the SAN was granulated and the finished product was obtained.

The SAN obtained as described above was used to prepare test samples measuring 50 mm in length x 50 mm in width × 3 mm in thickness by injection molding, and turbidity of the test samples was measured. The injection machine used was SJ-35C Dynamelt manufactured by Meiki Co., Ltd. The casting conditions were set such that the cylinder temperature was 220 ° C for all its front, middle and rear parts, the injection coefficient was 60% and the casting temperature was 60 ° C.

In addition, three test specimens were investigated on an NDH-2000 turbidity meter manufactured by Nippon Denshoku Industries Co., Ltd. using a photometric ball method and a C light source according to JIS K-7105-1981 to estimate the turbidity as an average value. measured in this way. In addition, the content of the acrylonitrile component (PAN) in the product was determined using a Perkin-Elmer 240011 CHNS / O Analyzer. Additionally, the melt flow index (MFI) was evaluated, which is an important indicator of the physical properties of the SAN at a measurement temperature of 200 ° C and a measurement mass of 5 kg, according to ASTM D-1238. Table 1 summarizes the results of measurements of the turbidity, the content of the acrylonitrile component and the melt flow index (MFI).

(An example embodiment of the invention 2)

In the production apparatus used in example 1 of the embodiment of the invention, another set of a channel 6 of the circulation outlet, a circulation pump 7, a cooler 8 and a channel 18 of the circulation input was installed, the flow rate of the starting material (F) was 2.43 m ³ / h. SANs were obtained under the same conditions as the conditions in Example 1 of the embodiment of the invention, with the exception of this parameter. Table 1 presents the results of measuring the turbidity, the content of the acrylonitrile component and the melt flow index (MFI) SAN.

Table 1 Example 1 embodiment of the invention Example 2 embodiment of the invention Turbidity% 1,1 1,1 A / B 15.0 15.0 A / C 0.81 0.40 D / c 0.32 0.32 E / f 97 82 PAN (wt.%) 31.1 31.1 MFI (g / 10 min) 3.3 3.2 SAN Production Process Rate (kg / h) 815 961

Claims (14)

1. A device for producing a polymer resin, including:
a polymerization tank including a main body and a protruding part that protrudes downward from the plane of the bottom of the main body and the lower part of which represents the cover of the lower part;
a mixing device comprising a drive mounted above the main body, a rotating axial mixer connected to the drive and extending from the drive to the protruding part, and a blade located on the side surface of the axial mixer;
a support element located on the lower cover of the protruding part, so as to close the side surface of the axial mixer without contact with it, and so that a gap is formed between the support element and the side surface of the axial mixer and between the support element and the lower surface of the axial mixer;
an outlet for draining the solution in the main body;
a protective element covering the lateral surface of the axial mixer without contact with it and forming a first flow channel between the protective element and the lateral surface of the axial mixer inside the protruding part;
first cooling means located inside the main body;
circulation cooling means including a circulation inlet channel located on a side surface of the protruding part so as to be opposite the protective element, a circulation line passing from the main body to the circulation inlet channel, and a second cooling means and a circulation pump connected to the circulation line at a midpoint ;
third cooling means arranged so as to close the outer wall of the polymerization vessel;
a feed material input channel connected to the protruding part and an element defining a flow channel are located between the support element and the protective element so as to close the side surface of the axial mixer and so as to fix the support element and the protective element, and where the element and where the defining the flow channel form a second flow channel between the lateral surface of the axial mixer and the element defining the flow channel, and a third flow channel for connecting the second flow channel to the input channel of the source material;
where the first to third flow channels constitute a continuous flow channel,
the highest end of the first flow channel is open inside the protruding part; and
the gap, part of the first flow channel, with the exception of the highest end, the second flow channel and the third flow channel are isolated from the inner zone of the protruding part. 2. A device for producing a polymer resin according to claim 1, where
the main body further includes a pressure relief element that opens when the internal pressure in the polymerization tank reaches a predetermined value or exceeds it to reduce the pressure inside the polymerization tank;
the circulation line is connected to the side surface of the main body and
the height from the tangent line of the main body to the highest point of the inner wall of the circulation line is 0.2 D or more, but not more than 0.5 D, provided that the inner diameter of the cylindrical part of the main body is D. 3. A device for producing a polymer resin according to claim 1, where
the first cooling means includes
a suction tube surrounding the paddle of the mixing device and including a cooling medium flowing inside the suction tube;
a tubular cooling coil located between the suction tube and the inner wall of the main body, and
ring main pipelines located in the upper and lower zones of the polymerization tank, so as to ensure the flow of the cooling medium through the tubular cooling coil;
a third cooling means including a cooling jacket, and
A / B is 6 m ² / m ³ or more, but not more than 25 m ² / m ³ , where A (m ² ) represents the "sum of the areas of the outer surfaces of the suction pipe, tubular cooling coil and ring main pipelines inside the main body and the area the outer wall of the main body, covered with a cooling jacket ", and B (m ³ ) represents the" internal volume of the polymerization tank ". 4. A device for producing a polymer resin according to claim 1, where the first cooling means includes
a suction tube surrounding the paddle of the mixing device and including a cooling medium flowing inside the suction tube;
a tubular cooling coil located between the suction tube and the inner wall of the main body, and
ring main pipelines located in the upper and lower zones of the polymerization tank, so as to ensure the flow of the cooling medium through the tubular cooling coil;
the second cooling means includes a cooler, the cooler includes a jacket with a cooling medium flowing in it, a tube connected to the circulation line and located inside the jacket, and a coil spring located inside the tube and capable of at least one reciprocating movement and rotational movement;
the third cooling means includes a cooling jacket, and A / C is 0.2 or more, but not more than 1.0, where A (m ² ) represents "the sum of the areas of the outer surfaces of the suction pipe, tubular cooling coil and annular main pipelines inside the main case and the area of the outer wall of the main body covered with a cooling jacket ", and C (m ² ) represents" the area of the inner surface of the cooler tube ". 5. The device for producing polymer resin according to claim 1, where the uppermost end of the protective element is located higher than the uppermost end of the inner wall of the channel of the circulation input, and lower than the surface of the bottom of the main body. 6. A device for producing a polymer resin according to claim 5, where the highest end of the protective element is located at a height of 0.5 D _N or higher than the highest end of the inner wall of the channel of the circulation input, provided that the inner diameter of the channel of the circulation input is D _N. 7. The device for producing a polymer resin according to claim 1, where the polymer resin is a copolymer resin. 8. The device for producing the polymer resin according to claim 7, where the copolymer-based resin is a styrene-acrylonitrile (SAN) copolymer resin. 9. A method of producing a polymer resin using a device for producing according to any one of claims 1 to 8, the method includes
preparing a polymerization vessel loaded with a polymerization solution;
the input of the source material through the input channel of the source material through the third flow channel, the second flow channel and the first flow channel into the protruding part;
carrying out a polymerization reaction in which a polymer resin is formed by mixing the starting material with the polymerization solution under the action of rotation of the axial mixer;
cooling the polymerization solution inside the polymerization tank with the first and third cooling means;
withdrawing the polymerization solution from the main body using a circulation pump, cooling the polymerization solution with a second cooling means, and then returning the polymerization solution to the protruding part through the circulation inlet channel; and
drainage of the polymerization solution through the channel of the drainage solution and then the separation of the polymer resin from the polymerization solution. 10. The method of producing a polymer resin according to claim 9, where the volumetric flow rate of the polymerization solution circulating inside the main body is 50 times or more, not more than 300 times the volumetric flow rate of the source material introduced through the input channel of the source material. 11. The method of producing a polymer resin according to claim 9, where the second cooling means includes a cooler, the cooler includes a jacket with a cooling medium flowing in it, a tube connected to the circulation line and located inside the jacket, and a coil spring located inside the tube capable of at least one reciprocating motion and rotational motion; and the ratio "(volumetric flow rate of the polymerization solution flowing inside the tube of the second cooling means) / (area of the inner surface of the tube of the second cooling means)" is 0.2 m ³ / m ² / h or higher, but not more than 0.5 m ³ / m ² / h 12. The method of producing the polymer resin according to claim 9, where the polymer resin is a resin based on a styrene-acrylonitrile copolymer (SAN) and the temperature of the starting material introduced through the input channel of the starting material into the protruding portion is -5 ° C or higher, but not above 20 ° C. 13. The polymerization tank for polymer resin, including the main body;
a protruding part that protrudes downward from the plane of the bottom of the main body and includes a lower part that represents the cover of the lower part;
a mixing device comprising a rotary axial mixer connected to a drive mounted above the main body and extending from the drive to the protruding part, and a blade located on the side surface of the axial mixer;
a support element located on the lower cover of the protruding part, so as to close the side surface of the axial mixer without contact with it, and so that a gap is formed between the support element and the side surface of the axial mixer and between the support element and the lower surface of the axial mixer;
an outlet for draining the solution in the main body;
a protective element covering the side surface of the axial mixer without contact with it and forming a first flow channel between the protective element and the side surface of the axial mixer inside the protruding part;
first cooling means located inside the main body;
a circulation inlet channel located on the side surface of the protruding part, so as to be opposite the protective element and to ensure the flow of the cooled polymerization solution in it;
a feed material input channel connected to the protruding part, and an element defining a flow channel and located between the support element and the protective element, so as to close the side surface of the axial mixer and fix the support element and the protective element, the element defining the flow channel and forming the second flow channel between the lateral surface of the axial mixer and the element defining the flow channel, and the third flow channel for connecting the second flow channel to the input channel of the source material;
where the first to third flow channels constitute a continuous flow channel,
the highest end of the first flow channel is open inside the protruding part; and
the gap, part of the first flow channel, with the exception of the highest end, the second flow channel and the third flow channel are isolated from the inner zone of the protruding part. 14. The polymerization tank for the polymer resin according to item 13, further comprising a third cooling means, located so as to close the outer wall of the main body.

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