Continuous production system suitable for methacrylic acid polymer

Abstract

The utility model discloses a continuous production system suitable for methacrylic acid series polymers, and belongs to the technical field of methacrylic acid series polymer production. The continuous production system comprises a mixing buffer tank, a complete mixing reaction kettle, a sectional tubular reactor and a de-ashing and strip-extruding all-in-one machine which are arranged in sequence, and a continuous passage for producing the methacrylic acid series polymer is formed among the mixing buffer tank, the complete mixing reaction kettle, the sectional tubular reactor and the de-ashing and strip-extruding all-in-one machine. The method can be well matched with a methacrylic acid polymer production process; according to the technical scheme, the specific structures of the complete mixing reaction kettle and the sectional tubular reactor are limited, so that the reaction heat can be accurately, efficiently and quickly removed, the balance between the polymerization conversion rate and the reaction heat is maintained, the continuous production is realized, and meanwhile, the effective production of the methacrylic acid series polymer is also realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of production system of methacrylic polymer, especially a kind of continuous production system suitable for methacrylic polymer, belong to methacrylic polymer production technical field. BACKGROUND

[0002] ‌Methacrylic polymer is a kind of high molecular material with wide application prospect, is the high molecular compound formed by methacrylic acid or its derivative monomer through polymerization reaction.Methacrylic polymer has uniqueness in chemical structure, and its alkyl side chain is methyl instead of hydrogen atom, and the polymer generally has higher transparency, good weathering resistance and other characteristics.Among them, polymethyl methacrylate (PMMA) is an important member of methacrylic polymer, and polymethyl methacrylate is also called organic glass or acrylic, which is a kind of high transparent, amorphous high molecular polymer.

[0003] At present, polymerization process mainly includes:

[0004] I. Suspension polymerization method, with water as continuous phase, the viscosity of polymerization system is low, and the viscosity of material changes little during reaction, which has the advantages of easy removal of polymerization heat, easy control of temperature, safe production operation, short process flow, etc.But due to the use of a large amount of water phase, the production capacity of suspension polymerization is low, which is not suitable for large-scale continuous production;And preparation process needs filtering, washing, drying and other complicated procedures, which reduces production efficiency, and there are problems of poor product purity and large amount of sewage;

[0005] II. Solution polymerization method, the viscosity of polymerization system is low, and mass transfer and heat transfer are easy to control, and the operation condition is stable, which can be large-scale and continuous production, and there is no sewage treatment problem.But there are problems of complex recovery and treatment process of organic solvent, and high cost, which may cause environmental pollution problem;

[0006] Third, the bulk polymerization method is suitable for continuous production, the product has high purity and transparency, the polymerization conversion rate is high, only a small amount of unreacted monomer needs to be recovered, and the energy consumption is low. However, due to the high viscosity of the polymerization system, the mass transfer and heat transfer control is difficult, and therefore the equipment and process operation process are harsh, and therefore a large amount of research has been carried out. For example, the prior art CN102933610A discloses a "methyl methacrylate polymer production method", which is mainly based on the bulk polymerization process, and a final product is obtained by multi-stage series connection of a complete mixing reactor and a pipeline reactor; the prior art CN104955853A discloses a "method for producing a methyl methacrylate polymer composition and a molded product", wherein the polymerization monomer and the auxiliary agent are supplied into a first complete mixing type reactor through a supply port of the reactor, and after reaction, the reaction is continued in a second complete mixing type reactor, and the obtained methyl methacrylate polymer composition is taken out through a discharge port of the second complete mixing type reactor; the prior art CN101338001A discloses an "optical grade PMMA continuous solution polymerization process and equipment used", wherein the equipment is composed of a refining distillation device, a polymerization reaction device, a two-stage devolatilization device and a wire drawing and granulation device; CN103130945A and CN103130946A both provide a PMMA continuous polymerization method, which adopts a three-completely-mixed-reactor series connection mode, and realizes the production of PMMA by pre-polymerization, secondary polymerization and tertiary polymerization in sequence.

[0007] Although the above-mentioned prior art all adopts the bulk polymerization method to produce the methyl methacrylate polymer, realizes the innovation and optimization of the polymerization process, but for the balance of the conversion rate and the reaction heat in the polymerization process, generally, the reaction section or the equipment is increased to control the conversion rate in each section or equipment, and finally the reaction heat is reduced, which not only increases the equipment cost and the energy consumption, but also the reaction heat cannot be effectively controlled, and finally, the effective production of the methyl methacrylate polymer is affected.

[0008] Therefore, a production system of the methyl methacrylate polymer capable of realizing rapid heat removal and ensuring the balance of the polymerization conversion rate and the reaction heat is needed, and is better matched with the production process of the methyl methacrylate polymer. SUMMARY

[0009] In order to overcome the deficiencies of the prior art, a continuous production system suitable for methacrylic polymer is provided. In the technical solution, through the cooperation of the mixing buffer tank, the full-mixing reaction kettle, the segmented column reactor and the deashing and extruding all-in-one machine, and the specific structure of the full-mixing reaction kettle and the segmented column reactor, the production system can better cooperate with the methacrylic polymer production process, ensure that the reaction heat can be accurately, efficiently and quickly removed, maintain the balance of the polymerization conversion rate and the reaction heat, realize continuous production, and effectively produce the methacrylic polymer.

[0010] In order to achieve the above technical purpose, the following technical solution is proposed:

[0011] The technical solution aims to provide a production system for continuously preparing methacrylic polymer, which comprises a mixing buffer tank, a full-mixing reaction kettle, a segmented column reactor and a deashing and extruding all-in-one machine.

[0012] The mixing buffer tank is connected with a methyl acrylate monomer metering tank through a methyl acrylate monomer feeding pipe, is also connected with an acrylic acid alkyl ester monomer metering tank through an acrylic acid alkyl ester monomer feeding pipe, is further connected with a (methyl) acrylic acid cyclic ester monomer metering tank through a (methyl) acrylic acid cyclic ester monomer feeding pipe, and is connected with a protective gas storage tank through a protective gas inlet pipe I; a displacement gas outlet is connected with a displacement gas outlet pipe on the mixing buffer tank; and a discharge port on the mixing buffer tank is connected with the full-mixing reaction kettle through a mixed material conveying pipe.

[0013] A methyl acrylate monomer feeding control valve and a methyl acrylate monomer metering pump are arranged on the methyl acrylate monomer feeding pipe, an acrylic acid alkyl ester monomer feeding control valve and an acrylic acid alkyl ester monomer metering pump are arranged on the acrylic acid alkyl ester monomer feeding pipe, a (methyl) acrylic acid cyclic ester monomer feeding control valve and a (methyl) acrylic acid cyclic ester monomer metering pump are arranged on the (methyl) acrylic acid cyclic ester monomer feeding pipe, a protective gas feeding control valve I is arranged on the protective gas inlet pipe I, an oxygen content analyzer is arranged on the displacement gas outlet pipe, a pressure sensor I and a temperature sensor I are arranged on the mixing buffer tank, and a mixed material conveying pump is arranged on the mixed material conveying pipe.

[0014] The full-mixing reaction kettle is arranged at the rear side of the working position of the mixing buffer tank, is connected with a solvent metering tank through a solvent feeding pipe, is also connected with an additive metering tank through an additive feeding pipe I, and is connected with the protective gas storage tank through a protective gas inlet pipe II.

[0015] The full-mixing reaction kettle is provided with a stirring device, a temperature control coil pipe is sleeved on the stirring device, one end of the temperature control coil pipe is connected with a heat-removing material inlet pipe, and the other end is connected with a heat-removing material outlet pipe; a three-paddle stirring mechanism is arranged at the lower part of the stirring device, the three-paddle stirring mechanism comprises paddle assemblies I, II and III which are sequentially arranged from bottom to top, the paddles in the paddle assembly I are twisted clockwise by 35-45 DEG C, the paddles in the paddle assembly II are twisted counterclockwise by 35-45 DEG C, and the paddles in the paddle assembly III are twisted clockwise by 35-45 DEG C; a discharge port of the full-mixing reaction kettle is connected with a sectional column-tube reactor through a prepolymerization reaction system conveying pipe;

[0016] A solvent feeding control valve and a solvent metering pump are arranged on the solvent feeding pipe, a auxiliary agent feeding control valve I and a auxiliary agent metering pump I are arranged on the auxiliary agent feeding pipe I, a protective gas feeding control valve II is arranged on the protective gas feeding pipe II, a heat-removing material feeding control valve is arranged on the heat-removing material inlet pipe, and a heat-removing material discharging control valve is arranged on the heat-removing material outlet pipe; a pressure sensor II and a temperature sensor II are arranged on the full-mixing reaction kettle; and a prepolymerization reaction system conveying pump is arranged on the prepolymerization reaction system conveying pipe;

[0017] In addition, a heating jacket is sleeved outside the full-mixing reaction kettle, a heat source in the heating jacket is high-temperature heat-conducting oil, a heat-conducting oil inlet pipe I is connected with an inlet of the heating jacket, and a heat-conducting oil outlet pipe I is connected with an outlet of the heating jacket; the heat-removing material in the temperature control coil pipe is liquid feed, the gasification temperature of the heat-removing material under normal pressure is higher than the set reaction temperature in the full-mixing reaction kettle by 5-10 DEG C, and the feeding temperature of the heat-removing material is lower than the set reaction temperature by 5-10 DEG C, for example, isopentyl alcohol with a boiling point of 131-132 DEG C can be selected when the set reaction temperature in the full-mixing reaction kettle is 120 DEG C, and isopentyl acetate with a boiling point of 142 DEG C can be selected when the set reaction temperature in the full-mixing reaction kettle is 132 DEG C; a heat-conducting oil feeding control valve I is arranged on the heat-conducting oil inlet pipe I, and a heat-conducting oil discharging control valve I is arranged on the heat-conducting oil outlet pipe I;

[0018] The sectional column-tube reactor is arranged at the rear side of the working position of the full-mixing reaction kettle, comprises a shell and at least two mixed flow units and at least two column-tube reaction units arranged in the shell, the mixed flow units and the column-tube reaction units are arranged at intervals and are sequentially distributed upwards; a feeding port is arranged on the lowermost mixed flow unit, and a discharge port is arranged on the uppermost column-tube reaction unit, and a continuous passage for polymerization reaction is formed between the feeding port, the mixed flow units, the column-tube reaction units and the discharge port;

[0019] Each mixed flow unit is connected with an auxiliary agent feeding pipe II, the bottom column-tube reaction unit is connected with a heat-conducting oil inlet pipe II, the top column-tube reaction unit is connected with a heat-conducting oil outlet pipe II, and the upper column-tube reaction unit and the lower column-tube reaction unit are connected through a heat-conducting oil communication pipe; and the discharge port of the sectional column-tube reactor is connected with a deashing and extruding integrated machine through a reactant conveying pipe;

[0020] The mixed flow unit comprises a mixed flow cavity communicated with the auxiliary agent feeding pipe II, and the column tube reaction unit comprises column tubes arranged longitudinally, and a temperature control cavity between the column tubes and the shell is used for containing heat conducting oil;

[0021] Preferably, the temperature control cavity is further connected with a cold oil feeding pipe, that is, both heat conducting oil and cold oil are integrated to comprehensively adjust the problem of the temperature control cavity, thereby effectively controlling the temperature in the column tubes and ensuring controllable operation of the reaction system.

[0022] The auxiliary agent feeding pipe II is provided with an auxiliary agent feeding control valve II and an auxiliary agent metering pump II, the heat conducting oil feeding pipe II is provided with a heat conducting oil feeding control valve II, the heat conducting oil discharge pipe II is provided with a heat conducting oil discharge control valve II, the cold oil feeding pipe is provided with a cold oil feeding control valve, and the reactant conveying pipe is provided with a reactant conveying pump.

[0023] The deashing and extruding integrated machine is arranged at the rear side of the sectional column tube reactor, the polymer outlet of the deashing and extruding integrated machine is connected with the methacrylic polymer storage tank, the waste outlet of the deashing and extruding integrated machine is connected with the monomer recovery device, and the monomer outlet of the monomer recovery device is connected with the mixing buffer tank through a reuse pipe.

[0024] The mixing buffer tank, the full-mixing reaction kettle, the sectional column tube reactor, the deashing and extruding integrated machine and the methacrylic polymer storage tank form a continuous channel for methacrylic polymer production.

[0025] In the technical solution, the positional relationships such as rear side of the work station, between, on, in, above, below, bottom, top, from bottom to top, one end, another end, lower part and the like are defined according to the actual use state, are conventional terms in the technical field, and are conventional terms used by the person skilled in the art in the actual use process.

[0026] In the description of the technical solution, it should be noted that, unless otherwise explicitly specified and limited, the terms such as setting and connecting should be understood in a broad sense, for example, can be fixedly connected, can be detachably connected, or integrally connected, can be mechanically connected, can be electrically connected, can be directly connected, can be indirectly connected through an intermediate medium, or can be connected inside two elements. For the person skilled in the art, the specific meanings of the above terms in the utility model can be understood according to the specific circumstances.

[0027] The technical solution has the following beneficial technical effects:

[0028] I. In the utility model, through the cooperation of the mixed buffer tank, the full-mixing reaction kettle, the sectional column reactor and the deashing and extruding integrated machine, the continuous passage for the production of the methacrylic acid polymer is formed among the mixed buffer tank, the full-mixing reaction kettle, the sectional column reactor and the deashing and extruding integrated machine, so that the production system can be better matched with the methacrylic acid polymer production process, and the continuous and large-scale production is realized.

[0029] II. In the utility model, through the setting of the full-mixing reaction kettle, the stirring device is arranged in the full-mixing reaction kettle, the temperature control coil pipe is arranged on the stirring device, one end of the temperature control coil pipe is connected with the heat removal inlet pipe, and the other end is connected with the heat removal outlet pipe, wherein, according to the mechanism of heat removal by vaporization of the heat removal material, the reaction heat can be accurately, efficiently and quickly removed, finally, the balance between the polymerization conversion rate and the reaction heat is maintained, the polymerization conversion rate is ensured to be within the control range, and the effective production of the methacrylic acid polymer is realized.

[0030] III. In the utility model, for the setting of the sectional column reactor, the sectional column reactor comprises at least two mixed flow units and at least two column reactor units, the mixed flow units and the column reactor units are arranged at intervals and are distributed upwards in sequence, a feeding port is arranged on the lowermost mixed flow unit, and a discharging port is arranged on the uppermost column reactor unit, and the continuous passage for the polymerization reaction is formed among the feeding port, the mixed flow unit, the column reactor unit and the discharging port. In the polymerization reaction process, the mixed flow unit can ensure the segmented addition of the multiple varieties and multiple regions of the auxiliary agent, control the reaction progress, the multiple-region reactor is connected in series and the heat is removed (the column reactor unit), the rapid heat removal is provided, the segmented temperature regulation is matched, not only the accurate control of the conversion rate and the temperature can be realized, but also the energy consumption per ton of product can be reduced, finally, the optical grade methacrylic acid polymer with high stability is obtained. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 Schematic diagram of the working principle of the production system in the utility model (one);

[0032] Figure 2 Schematic diagram of the working principle of the production system in the utility model (two);

[0033] Figure 3 Device structure block diagram of the production system in the utility model;

[0034] Figure 4 Structure schematic diagram of the sectional column reactor in the utility model;

[0035] Figure 5 Flow chart of the production process in the utility model;

[0036] In the figure, 1, mixing buffer tank, 100, alkyl methacrylate monomer feeding pipe, 101, alkyl methacrylate monomer metering tank, 102, alkyl acrylate monomer feeding pipe, 103, alkyl acrylate monomer metering tank, 104, (meth) acrylic cyclic ester monomer feeding pipe, 105, (meth) acrylic cyclic ester monomer metering tank, 106, protective gas inlet pipe I, 107, displacement gas outlet pipe, 108, mixed material conveying pipe;

[0037] 2, full-mixing reaction kettle, 200, solvent feeding pipe, 201, solvent metering tank, 202, additive feeding pipe I, 203, additive metering tank, 204, protective gas inlet pipe II, 205, three-paddle stirring mechanism, 206, temperature control coil, 207, heat-removing material inlet pipe, 208, heat-removing material outlet pipe, 209, prepolymerization reaction system conveying pipe, 210, heating jacket, 211, heat-conducting oil inlet pipe I, 212, heat-conducting oil outlet pipe I;

[0038] 3, sectionalized tubular reactor, 300, shell, 301, mixed-flow unit, 302, tubular reaction unit, 303, mixed-flow cavity, 304, tube, 305, temperature control cavity, 306, additive feeding pipe II, 307, heat-conducting oil inlet pipe II, 308, heat-conducting oil outlet pipe II, 309, heat-conducting oil communication pipe, 310, reactant conveying pipe, 311, cold oil feeding pipe;

[0039] 4, dehydrated extrusion integrated machine;

[0040] 5, protective gas storage tank;

[0041] 6, methacrylic polymer storage tank;

[0042] 7, monomer recycling device, 700, recycling pipe;

[0043] 9. Alkyl methacrylate monomer feed control valve; 10. Alkyl methacrylate monomer metering pump; 11. Alkyl acrylate monomer feed control valve; 12. Alkyl acrylate monomer metering pump; 13. (Meth)acrylate cyclic ester monomer feed control valve; 14. (Meth)acrylate cyclic ester monomer metering pump; 15. Protective gas feed control valve I; 16. Oxygen content analyzer; 17. Pressure sensor I; 18. Temperature sensor I; 19. Mixture conveying pump; 20. Solvent feed control valve; 22. Solvent metering pump; 23. Additive feed control valve I; 24. Additive metering pump I; 25. 26. Protective gas feed control valve II; 27. Heat transfer material feed control valve; 28. Heat transfer material discharge control valve; 29. ​​Pressure sensor II; 30. Temperature sensor II; 31. Prepolymerization reaction system transfer pump; 32. Heat transfer oil feed control valve I; 33. Heat transfer oil discharge control valve I; 34. Additive feed control valve II; 35. Additive metering pump II; 36. Heat transfer oil feed control valve II; 37. Heat transfer oil discharge control valve II; 38. Cold oil feed control valve; 39. Reactant transfer pump; 40. Pressure sensor III; 41. Temperature sensor III; 42. Pressure sensor IV; 43. Temperature sensor IV. Detailed Implementation

[0044] The technical solutions in the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0045] Example 1

[0046] This embodiment provides a continuous production system suitable for methacrylic polymers, such as... Figure 1 , 3 As shown, it includes a mixing buffer tank 1, a fully mixed reaction vessel 2, a segmented tubular reactor 3, and a deashing and extrusion integrated machine 4, arranged in sequence. Among them,

[0047] Mixing buffer tank 1: The discharge port of mixing buffer tank 1 is connected to the total mixing reactor 2 through the mixing material conveying pipe 108;

[0048] Total mixing reactor 2: Located behind the mixing buffer tank 1, the total mixing reactor 2 is equipped with a stirring device, and a temperature control coil 206 is fitted on the stirring device. One end of the temperature control coil 206 is connected to the heat transfer material inlet pipe 207, and the other end is connected to the heat transfer material outlet pipe 208. The discharge port of the total mixing reactor 2 is connected to the segmented tubular reactor 3 through the prepolymerization reaction system conveying pipe 209.

[0049] Segmented tubular reactor 3: Located behind the station of the total mixing reactor 2, such as Figure 4 As shown, the segmented tubular reactor 3 includes a shell 300 and at least two mixing units 301 and at least two tubular reaction units 302 disposed within the shell 300. The mixing units 301 and the tubular reaction units 302 are arranged at intervals and distributed upwards in sequence. The lowermost mixing unit 301 is provided with a feed inlet, and the uppermost tubular reaction unit 302 is provided with a discharge outlet. The feed inlet, the mixing unit 301, the tubular reaction unit 302 and the discharge outlet form a continuous pathway for polymerization reaction. The discharge outlet of the segmented tubular reactor 3 is connected to the deashing and extrusion integrated machine 4 through a reactant conveying pipe 310.

[0050] Deashing and extrusion integrated machine 4: Located at the rear of the work station of the segmented tubular reactor 3, the polymer outlet of the deashing and extrusion integrated machine 4 is connected to the methacrylic acid polymer storage tank 6.

[0051] A continuous pathway for the production of methacrylic polymers is formed between the mixing buffer tank 1, the fully mixed reactor 2, the segmented tubular reactor 3, the deashing and extrusion integrated machine 4, and the methacrylic polymer storage tank 6.

[0052] In addition, a mixture conveying pump 19 is provided on the mixture conveying pipe 108, a prepolymerization reaction system conveying pump 30 is provided on the prepolymerization reaction system conveying pipe 209, and a reactant conveying pump 38 is provided on the reactant conveying pipe 310, to ensure the orderly and effective conveying of the mixture, the prepolymerization reaction system, and the reaction products.

[0053] The fully mixed reactor 2 is equipped with a temperature control coil 206 containing a heat transfer medium. Based on the mechanism of heat transfer through vaporization, the heat of reaction is precisely, efficiently, and rapidly removed, ultimately maintaining a balance between polymerization conversion and heat of reaction, ensuring the polymerization conversion remains within a controlled range, and achieving efficient production of methacrylic acid polymers. For example, if the heat transfer medium in the temperature control coil 206 is a liquid feed, its vaporization temperature at atmospheric pressure is 5–10°C higher than the set reaction temperature in the fully mixed reactor 2, and its feed temperature is 5–10°C lower than the set reaction temperature. For instance, when the set reaction temperature in the fully mixed reactor 2 is 120°C, isoamyl alcohol with a boiling point of 131–132°C can be selected; when the set reaction temperature in the fully mixed reactor 2 is 132°C, isoamyl acetate with a boiling point of 142°C can be selected.

[0054] Within the segmented tubular reactor 3, multiple reaction sections are concentrated in the shell 300, achieving centralized and efficient heat exchange through the tubular 304 heat exchanger structure. This allows for precise temperature control of the entire polymerization reaction process. Subsequently, additives (such as initiators and chain transfer agents) are added at multiple reaction points, ensuring that the conversion rate and degree of polymerization at each reaction point remain within a narrow range, achieving precise control and guaranteeing a safe, reliable, continuous, and controllable reaction process. Furthermore, concentrating the polymerization reaction within the tubular 304 reactor not only reduces the use of power equipment but also enables high-intensity heat exchange through the tubular 304 heat exchange structure. Heat from the previous reaction zone is then used for the next reaction zone, achieving energy coupling and reducing energy consumption, among other benefits.

[0055] Example 2

[0056] Based on Example 1, this example further defines the arrangement of the mixing buffer tank 1 to achieve effective feeding of monomer raw materials, ensure the oxygen content of each monomer raw material, and monitor the pressure and temperature in the mixing buffer tank 1 to facilitate the prepolymerization reaction in the subsequent fully mixed reactor 2.

[0057] The mixing buffer tank 1 is connected to the alkyl methacrylate monomer metering tank 101 via the alkyl methacrylate monomer feed pipe 100, the alkyl acrylate monomer metering tank 103 via the alkyl acrylate monomer feed pipe 102, the cyclic methacrylate monomer metering tank 105 via the (meth)acrylate monomer feed pipe 104, and the protective gas storage tank 5 via the protective gas inlet pipe I 106; the displacement gas outlet of the mixing buffer tank 1 is connected to the displacement gas outlet pipe 107.

[0058] Among them, such as Figure 2 As shown, the alkyl methacrylate monomer feed pipe 100 is equipped with an alkyl methacrylate monomer feed control valve 9 and an alkyl methacrylate monomer metering pump 10; the alkyl acrylate monomer feed pipe 102 is equipped with an alkyl acrylate monomer feed control valve 11 and an alkyl acrylate monomer metering pump 12; the (meth)acrylate cyclic ester monomer feed pipe 104 is equipped with a (meth)acrylate cyclic ester monomer feed control valve 13 and a (meth)acrylate cyclic ester monomer metering pump 14; the protective gas inlet pipe I 106 is equipped with a protective gas feed control valve I 15; the displacement gas outlet pipe 107 is equipped with an oxygen content analyzer 16; and the mixing buffer tank 1 is equipped with a pressure sensor I 17 and a temperature sensor I 18.

[0059] As a preferred embodiment, an electric signal control loop can be formed between the alkyl methacrylate monomer metering pump 10 and the alkyl methacrylate monomer feed control valve 9 through the DCS control system. For example, the alkyl methacrylate monomer metering pump 10 detects the feed condition in the alkyl methacrylate monomer feed pipe 100 and feeds back the signal to the DCS control system. The DCS control system analyzes, calculates and issues instructions to regulate the feed of the alkyl methacrylate monomer feed control valve 9 according to the setting of the internal reference value, and finally realizes the effective feed of the alkyl methacrylate monomer and indirectly ensures the effectiveness of the subsequent prepolymerization reaction and polymerization reaction, and regulates the conversion rate.

[0060] For the feed of the alkyl acrylate monomer and the cyclic (meth)acrylate monomer, the above-mentioned method can also be used.

[0061] Example 3

[0062] On the basis of Examples 1-2, in order to realize the effective feed of the solvent and the auxiliary agent, and to monitor the pressure and temperature in the full-mixing reaction kettle 2, facilitate the polymerization reaction in the subsequent sectional tubular reactor 3, the arrangement and specific structure of the full-mixing reaction kettle 2 are further limited:

[0063] The full-mixing reaction kettle 2 is connected with a solvent metering tank 201 through a solvent feed pipe 200, and is also connected with an auxiliary agent metering tank 203 through an auxiliary agent feed pipe I 202, and is connected with a protective gas storage tank 5 through a protective gas inlet pipe II 204. As shown in Figure 2 The solvent feed pipe 200 is provided with a solvent feed control valve 20 and a solvent metering pump 22, the auxiliary agent feed pipe I 202 is provided with an auxiliary agent feed control valve I 23 and an auxiliary agent metering pump I 24, and the protective gas inlet pipe II is provided with a protective gas feed control valve II 25. Among them, the setting of the solvent feed control valve 20 and the solvent metering pump 22 ensures the effective and controllable feed of the solvent; the setting of the auxiliary agent feed control valve I 23 and the auxiliary agent metering pump I 24 ensures the effective and controllable feed of the auxiliary agent; and the setting of the protective gas feed control valve II 25 ensures the effective entry of the protective gas into the full-mixing reaction kettle 2;

[0064] The heat-removing material inlet pipe 207 is provided with a heat-removing material inlet control valve 26, and the heat-removing material outlet pipe 208 is provided with a heat-removing material outlet control valve 27; the full-mixing reaction kettle 2 is provided with a pressure sensor II 28 and a temperature sensor II 29; the full-mixing reaction kettle 2 is provided with a heating jacket 210 outside, the heating jacket 210 is connected with a heat-conducting oil inlet pipe I 211 at the inlet, the heat-conducting oil inlet pipe I 211 is provided with a heat-conducting oil inlet control valve I 31; the heating jacket 210 is connected with a heat-conducting oil outlet pipe I 212 at the outlet, and the heat-conducting oil outlet pipe I 212 is provided with a heat-conducting oil outlet control valve I 32. Through the arrangement of the heat-removing material inlet control valve 26, the heat-removing material outlet control valve 27, the temperature sensor II 29, the heat-conducting oil inlet control valve I 31 and the heat-conducting oil outlet control valve I 32, the temperature in the full-mixing reaction kettle 2 is comprehensively controlled, and the accurate, effective and controllable removal of reaction heat is ensured. As a preferred embodiment, an electrical signal control loop can be formed between the DCS control system, the temperature sensor I 18, the temperature sensor II 29, the heat-removing material inlet control valve 26, the heat-removing material outlet control valve 27, the heat-conducting oil inlet control valve I 31 and the heat-conducting oil outlet control valve I 32, and the like.

[0065] In addition, the lower part of the stirring device is provided with a three-paddle stirring mechanism 205, which includes paddle assembly I, paddle assembly II and paddle assembly III distributed in sequence from bottom to top, the paddles in the paddle assembly I are twisted clockwise by 35-45 degrees, the paddles in the paddle assembly II are twisted counterclockwise by 35-45 degrees, and the paddles in the paddle assembly III are twisted clockwise by 35-45 degrees.

[0066] In addition, the lower part of the stirring device is provided with a three-paddle stirring mechanism 205, which includes paddle assembly I, paddle assembly II and paddle assembly III distributed in sequence from bottom to top, the paddles in the paddle assembly I are twisted clockwise by 35-45 degrees, the paddles in the paddle assembly II are twisted counterclockwise by 35-45 degrees, and the paddles in the paddle assembly III are twisted clockwise by 35-45 degrees.

[0067] Example 4

[0068] On the basis of examples 1-3, the present embodiment further limits the mixed-flow unit 301 and the tube reactor unit 302 to further illustrate the present application.

[0069] The mixed-flow unit 301 is connected with an additive inlet pipe II 306, the bottom tube reactor unit 302 is connected with a heat-conducting oil inlet pipe II 307 (generally high-temperature heat-conducting oil), the top tube reactor unit 302 is connected with a heat-conducting oil outlet pipe II 308, and the upper tube reactor unit 302 and the lower tube reactor unit 302 are connected through a heat-conducting oil communication pipe 309.

[0070] The mixed flow unit 301 comprises a mixed flow cavity 303 communicated with the auxiliary agent feeding pipe II 306, the column tube reaction unit 302 comprises column tubes 304 arranged longitudinally, and the temperature control cavity 305 between the column tubes 304 and the shell 300 is used for containing heat conducting oil. In addition, the temperature control cavity 305 is also connected with a cold oil feeding pipe 311 (generally low-temperature heat conducting oil), that is, both high-temperature heat conducting oil and low-temperature heat conducting oil are used to jointly adjust the temperature of the temperature control cavity 305, so as to effectively control the temperature in the column tubes 304 and ensure the controllable progress of the reaction system.

[0071] The auxiliary agent feeding control valve II 33 and the auxiliary agent metering pump II 34 are arranged on the auxiliary agent feeding pipe II 306, the heat conducting oil feeding control valve II 35 is arranged on the heat conducting oil feeding pipe II 307, the heat conducting oil discharging control valve II 36 is arranged on the heat conducting oil discharging pipe II 308, and the cold oil feeding control valve 37 is arranged on the cold oil feeding pipe 311. The pressure sensor III 39 and the temperature sensor III 40 are distributed on each mixed flow unit 301, and the pressure sensor IV 41 and the temperature sensor IV 42 are distributed on the column tube reaction unit 302. As a preferred embodiment, an electric signal control loop is formed among the temperature sensor III 40, the temperature sensor IV 42, the heat conducting oil feeding control valve II 35, the heat conducting oil discharging control valve II 36 and the cold oil feeding control valve 37 through the DCS control system, and the like.

[0072] Example 5

[0073] On the basis of examples 1-4, in order to improve the utilization rate of monomer raw materials and be friendly to the environment, the present embodiment is further limited as follows:

[0074] The waste outlet of the deashing and extruding all-in-one machine 4 is connected with the monomer recovery device 7, and the monomer outlet of the monomer recovery device 7 is connected with the mixing buffer tank 1 through the recycling pipe 700. The waste gas, which is separated from the polymer material in the deashing and extruding all-in-one machine 4, comprises unreacted monomers, solvents, oligomers and auxiliary agents.

[0075] The polymer material is subjected to subsequent temporary storage, granulation, packaging and the like.

[0076] The waste gas, which comprises unreacted monomers, solvents, oligomers and auxiliary agents, is introduced into the monomer recovery device 7, and after separation, waste liquid, waste gas, unreacted monomers and solvents are obtained. The recovered unreacted monomers can be recycled to the batching process.

[0077] Example 6

[0078] On the basis of examples 1-5, the present embodiment provides a production process for continuously preparing a methacrylic polymer, as shown in the following formula: Figure 5 The production process comprises the following steps:

[0079] S1: the raw materials of alkyl methacrylate monomer, alkyl acrylate monomer and cyclic (meth)acrylate monomer are added into a mixing buffer tank until the total volume of the raw materials reaches 80% of the internal volume of the mixing buffer tank;

[0080] The raw materials are mixed uniformly to obtain a mixture; then, high-purity Ar or N2 is introduced into the mixing buffer tank to replace the gas in the mixing buffer tank;

[0081] In the mixing buffer tank, the oxygen content in each monomer raw material is ≤1 ppm; the content of alkyl methacrylate monomer is 68-95%, the content of alkyl acrylate monomer is 3-30%, and the content of cyclic (meth)acrylate monomer is 2-15%, based on the total mass of the monomer raw materials; the pressure is 20-50 KPa (gauge pressure), and the temperature is 20-50℃;

[0082] S2: the mixture after gas replacement obtained in step S1, a solvent and an additive are added into a full-mixing reaction kettle, the temperature in the full-mixing reaction kettle is raised to 90-140℃ at a speed of 1-3℃ / min; then, the reaction is maintained for 30-240 min to obtain a prepolymerization reaction system;

[0083] In the full-mixing reaction kettle, the amount of the solvent added is 1-10% of the total amount of the monomer raw materials, and the amount of the additive added is 0.05-0.3% of the total amount of the monomer raw materials; the difference between the actual maximum temperature of the prepolymerization reaction and the set temperature is not higher than 10℃, the pressure is 0.5-2.0 MPa, the oxygen content is ≤1 ppm, and the conversion rate of alkyl methacrylate monomer is 30-50%;

[0084] S3: the prepolymerization reaction system obtained in step S2 is introduced into a staged tubular reactor, and the temperature in the staged tubular reactor is controlled to be 140-200℃, the pressure is 1.5-3.5 MPa, the additive is added again in an amount of 0.04-0.55%, and the moving speed of the material in the tubular reactor is 0.001-0.1 m / s, and finally a slurry product is obtained;

[0085] Further, in the staged tubular reactor, the temperature of each section gradually increases along the direction of the material flow;

[0086] As a preferred embodiment, the staged tubular reactor comprises a first reaction zone, a second reaction zone and a third reaction zone arranged in sequence from bottom to top, and in the first reaction zone, the additive is added again in an amount of 0.02-0.2% of the total amount of the monomer raw materials, the material is maintained for 20-100 min, the temperature is 140-155℃, and the total conversion rate of alkyl methacrylate monomer is 40-55%;

[0087] The second section of the reaction zone is controlled as follows: the amount of the additive added again is 0.01-0.2% of the total amount of the monomer raw materials, the material stays for 10-80 min, the temperature is 155-175℃, and the total conversion rate of the alkyl methacrylate monomers is 50-65% cumulatively;

[0088] The third section of the reaction zone is controlled as follows: the amount of the additive added again is 0.01-0.15% of the total amount of the monomer raw materials, the material stays for 5-60 min, the temperature is 175-200℃, and the total conversion rate of the alkyl methacrylate monomers is 60-75% cumulatively;

[0089] Meanwhile, the temperature relationship in the three sections of the reaction zone is as follows: 7≤the temperature of the second section of the reaction zone-the temperature of the first section of the reaction zone=the temperature of the third section of the reaction zone-the temperature of the second section of the reaction zone≤20, that is, the temperature difference between the adjacent sections of the reaction zone is equal, and 7℃≤the temperature difference≤20℃;

[0090] S4: descaling separation: the slurry product obtained in step S3 is introduced into a descaling extruder, and descaling separation is carried out at a temperature of 200-280℃ and an absolute pressure of 10-40 KPa for 10-30 min, to obtain a polymer product.

[0091] Further, before the ingredients are mixed, the alkyl methacrylate monomers, the alkyl acrylate monomers and the cyclic (meth)acrylate monomers are all refined to remove the polymerization inhibitors, and then are introduced into a mixing buffer tank under the action of a pipeline mixed gas.

[0092] Among them, for each monomer raw material:

[0093] The alkyl methacrylate monomers include one or a combination of two or more of methyl methacrylate, ethyl methacrylate, propyl methacrylate and isooctyl (meth)acrylate;

[0094] The alkyl acrylate monomers include one or a combination of two or more of methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate and isooctyl acrylate;

[0095] The cyclic (meth)acrylate monomers include one or a combination of two or more of cyclohexyl methacrylate, isobornyl acrylate, isobornyl methacrylate and benzyl methacrylate;

[0096] The solvent includes one or a combination of two or more of methanol, ethanol, benzene, toluene, methyl acetate and ethyl acetate;

[0097] As a preferred embodiment, the ingredients include methyl methacrylate with a content of 80-97%, methyl acrylate with a content of 1-10%, isobornyl acrylate with a content of 1-8% and methanol with a content of 1-5%;

[0098] As another preferred, the material comprises 80-97% of methyl methacrylate, 1-10% of ethyl acrylate, 1-7% of isobornyl methacrylate and 1-5% of methanol;

[0099] As another preferred, the material comprises 80-97% of methyl methacrylate, 1-5% of isooctyl acrylate, 1-5% of benzyl methacrylate and 1-5% of ethanol;

[0100] As another preferred, the material comprises 80-95% of methyl methacrylate, 5-10% of propyl acrylate, 2-7% of cyclohexyl methacrylate and 2-5% of ethanol;

[0101] As another preferred, the material comprises 75-95% of methyl methacrylate, 2-5% of isooctyl methacrylate, 1-3% of isobornyl acrylate and 2-5% of methyl acetate;

[0102] For the auxiliary agent: including initiator and chain transfer agent;

[0103] The initiator is azo compound or organic peroxide compound. The azo compound is preferably one or a combination of two of azobisisobutyronitrile and azobisisoheptyl nitrile;

[0104] The organic peroxide compound is preferably one or a combination of two or more of dibenzoyl peroxide, dodecanoyl peroxide, di-t-butyl peroxide, dicumyl peroxide and diisopropyl peroxydicarbonate;

[0105] In the full-mixing reaction kettle, the initiator is preferably one or a combination of two or more of azobisisobutyronitrile, dibenzoyl peroxide, di-t-butyl peroxide and azobisisoheptyl nitrile, and the initiator is added in an amount of 0.005-0.03% of the total amount of monomer raw materials; in the staged tubular reactor, the initiator in the first reaction zone and the second reaction zone is preferably one or a combination of two or more of dodecanoyl peroxide, dicumyl peroxide and diisopropyl peroxydicarbonate, and the initiator is added in an amount of 0.005-0.02% of the total amount of monomer raw materials; the initiator in the third reaction zone is preferably one or a combination of two of azobisisoheptyl nitrile and azobisisobutyronitrile, and the initiator is added in an amount of 0.001-0.01% of the total amount of monomer raw materials;

[0106] The chain transfer agent is one or a combination of two or more of benzyl dithiobenzoate, isopropyl phenyl dithiobenzoate, phenethyl dithiobenzoate and 2,4-diphenyl-4-methyl-1-pentene.

[0107] The chain transfer agent is preferably added in an amount of 0.05-0.3% of the total monomer raw material in a full-mixing reaction kettle; in a segmented tubular reactor, the chain transfer agent is added in an amount of 0.02-0.2% of the total monomer raw material in the first reaction zone, 0.01-0.2% of the total monomer raw material in the second reaction zone, and 0.01-0.15% of the total monomer raw material in the third reaction zone.

[0108] The total amount of initiator added is 0.01-0.1% and the total amount of chain transfer agent added is 0.01-1.0%, based on the total amount of the three monomer esters being 100%. In actual production, the (meth) alkyl acrylate, initiator and transfer agent can be mixed in an air-tight manner and then injected into the material through the feeding port.

[0109] The above is only a preferred embodiment of the present application, and does not limit the present application in any form. Any simple modification or equivalent change made according to the technical essence of the present application falls within the scope of protection of the present application.

Claims

1. A continuous production system for methacrylic polymers, characterized in that, It comprises a mixing buffer tank (1), a full-mixing reaction kettle (2), a sectionalized column reactor (3) and a deashing and extruding integrated machine (4) arranged in sequence, and the mixing buffer tank (1) is connected with the full-mixing reaction kettle (2) through a mixing material delivery pipe (108) at a discharge port of the mixing buffer tank (1); The full-mixing reaction kettle (2) is arranged at the rear side of the working position of the mixing buffer tank (1), and a stirring device is arranged in the full-mixing reaction kettle (2), a temperature control coil (206) is sleeved on the stirring device, one end of the temperature control coil (206) is connected with a heat removal material inlet pipe (207), and the other end is connected with a heat removal material outlet pipe (208); the full-mixing reaction kettle (2) is connected with the sectionalized column reactor (3) through a prepolymerization reaction system delivery pipe (209) at a discharge port of the full-mixing reaction kettle (2); The sectionalized column reactor (3) is arranged at the rear side of the working position of the full-mixing reaction kettle (2), and the sectionalized column reactor (3) comprises a shell (300) and at least two mixed flow units (301) and at least two column reactor units (302) arranged in the shell (300), the mixed flow units (301) and the column reactor units (302) are arranged in intervals and are distributed upwards in sequence; a feed inlet is arranged on the lowermost mixed flow unit (301), and a discharge port is arranged on the uppermost column reactor unit (302), and a continuous passage for polymerization reaction is formed between the feed inlet, the mixed flow units (301), the column reactor units (302) and the discharge port; the sectionalized column reactor (3) is connected with the deashing and extruding integrated machine (4) through a reaction material delivery pipe (310) at a discharge port of the sectionalized column reactor (3); The deashing and extruding integrated machine (4) is arranged at the rear side of the working position of the sectionalized column reactor (3), and a polymer outlet of the deashing and extruding integrated machine (4) is connected with a methacrylic polymer storage tank (6); A continuous passage for methacrylic polymer production is formed between the mixing buffer tank (1), the full-mixing reaction kettle (2), the sectionalized column reactor (3), the deashing and extruding integrated machine (4) and the methacrylic polymer storage tank (6).

2. The continuous production system suitable for methacrylic polymers according to claim 1, characterized in that, The mixing buffer tank (1) is connected with a methacrylic monomer metering tank (101) through a methacrylic monomer feed pipe (100), is connected with an acrylic monomer metering tank (103) through an acrylic monomer feed pipe (102), is connected with a (meth) acrylic cyclic ester monomer metering tank (105) through a (meth) acrylic cyclic ester monomer feed pipe (104), and is connected with a protective gas storage tank (5) through a protective gas inlet pipe I (106); and a displacement gas outlet of the mixing buffer tank (1) is connected with a displacement gas outlet pipe (107).

3. The continuous production system suitable for methacrylic polymers according to claim 2, characterized in that, The alkyl methacrylate monomer feeding pipe (100) is provided with an alkyl methacrylate monomer feeding control valve (9) and an alkyl methacrylate monomer metering pump (10), the alkyl acrylate monomer feeding pipe (102) is provided with an alkyl acrylate monomer feeding control valve (11) and an alkyl acrylate monomer metering pump (12), and the (methyl) cyclic ester monomer feeding pipe (104) is provided with a (methyl) cyclic ester monomer feeding control valve (13) and a (methyl) cyclic ester monomer metering pump (14); the protective gas inlet pipe I (106) is provided with a protective gas feeding control valve I (15), the displacement gas outlet pipe (107) is provided with an oxygen content analyzer (16), the mixing buffer tank (1) is provided with a pressure sensor I (17) and a temperature sensor I (18), and the mixed material conveying pipe (108) is provided with a mixed material conveying pump (19).

4. The continuous production system suitable for methacrylic polymer according to claim 1, characterized by, The full-mixing reaction kettle (2) is connected with a solvent metering tank (201) through a solvent feeding pipe (200), is connected with an additive metering tank (203) through an additive feeding pipe I (202), and is connected with a protective gas storage tank (5) through a protective gas inlet pipe II (204).

5. The continuous production system suitable for methacrylic polymers according to claim 4, characterized in that, The solvent feeding pipe (200) is provided with a solvent feeding control valve (20) and a solvent metering pump (22), the additive feeding pipe I (202) is provided with an additive feeding control valve I (23) and an additive metering pump I (24); the protective gas body inlet pipe II is provided with a protective gas feeding control valve II (25), the heat-removing material inlet pipe (207) is provided with a heat-removing material feeding control valve (26), the heat-removing material outlet pipe (208) is provided with a heat-removing material discharge control valve (27); the full-mixing reaction kettle (2) is provided with a pressure sensor II (28) and a temperature sensor II (29); and the prepolymerization reaction system conveying pipe (209) is provided with a prepolymerization reaction system conveying pump (30).

6. The continuous production system suitable for methacrylic polymers according to claim 5, characterized in that, The full-mixing reaction kettle (2) is provided with a heating jacket (210) outside, the heating jacket (210) is connected with a heat-conducting oil inlet pipe I (211) at the inlet, and the heat-conducting oil inlet pipe I (211) is provided with a heat-conducting oil feeding control valve I (31); the heating jacket (210) is connected with a heat-conducting oil outlet pipe I (212) at the outlet, and the heat-conducting oil outlet pipe I (212) is provided with a heat-conducting oil discharge control valve I (32).

7. The system for the continuous production of methacrylic polymers according to any of claims 1-6, characterized in that, The lower part of the stirring device is provided with a three-paddle stirring mechanism (205), the three-paddle stirring mechanism (205) comprises paddle assembly I, paddle assembly II and paddle assembly III which are sequentially arranged from bottom to top, the paddle in the paddle assembly I is twisted clockwise by 35-45 degrees, the paddle in the paddle assembly II is twisted counterclockwise by 35-45 degrees, and the paddle in the paddle assembly III is twisted clockwise by 35-45 degrees.

8. The continuous production system suitable for methacrylic polymer according to claim 1, characterized by, The mixing unit (301) is connected with an additive feeding pipe II (306), the bottom tube reaction unit (302) is connected with a heat-conducting oil inlet pipe II (307), the top tube reaction unit (302) is connected with a heat-conducting oil outlet pipe II (308), and the upper-stage tube reaction unit (302) and the lower-stage tube reaction unit (302) are connected through a heat-conducting oil communication pipe (309).

9. The continuous production system suitable for methacrylic polymers according to claim 8, characterized in that, The mixed flow unit (301) comprises a mixed flow cavity (303) communicated with an auxiliary agent feeding pipe II (306), and the column reactor unit (302) comprises columns (304) arranged longitudinally, and a temperature control cavity (305) between the columns (304) and the shell (300) is used for containing heat conducting oil.

10. The continuous production system suitable for methacrylic polymers according to claim 9, characterized in that, The temperature control cavity (305) is further connected with a cold oil feeding pipe (311); An auxiliary agent feeding control valve II (33) and an auxiliary agent metering pump II (34) are arranged on the auxiliary agent feeding pipe II (306), a heat conducting oil feeding control valve II (35) is arranged on a heat conducting oil feeding pipe II (307), a heat conducting oil discharging control valve II (36) is arranged on a heat conducting oil discharging pipe II (308), a cold oil feeding control valve (37) is arranged on the cold oil feeding pipe (311), and a reactant conveying pump (38) is arranged on the reactant conveying pipe (310); pressure sensors III (39) and temperature sensors III (40) are distributed on each mixed flow unit (301), and pressure sensors IV (41) and temperature sensors IV (42) are distributed on the column reactor unit (302).

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