Continuous production process for dehydration polymerization of polyarylene sulfide resin

Abstract

The invention discloses a continuous production process for dehydration polymerization of polyarylene sulfide resin, which takes a sulfur source and a dihalo aromatic compound as raw materials and organic amide as a solvent to carry out dehydration and polymerization reaction, and comprises the following steps: (1) dehydration: continuously introducing all the raw materials except the dihalo aromatic compound into N dehydration reaction kettles connected in series, the N dehydration reaction kettles connected in series are continuously heated in a segmented temperature control mode, and N is larger than or equal to 3; vaporized steam in the N dehydration reaction kettles connected in series is introduced into a distillation tower, after distillation, reflux liquid at the bottom of the distillation tower can flow back to the N dehydration reaction kettles, and the principle that reflux liquid with the temperature close to that of the dehydration reaction kettles returns to the dehydration reaction kettles is adopted; and (2) continuously pumping the dehydrated liquid obtained after treatment and a dihalo aromatic compound into a polymerization reactor, and carrying out heating polymerization and post-treatment to continuously produce the polyarylene sulfide resin. According to the continuous production process disclosed by the invention, the product dehydration and polymerization process is stable and controllable.

Description

Technical Field

[0001] The invention relates to the technical field of polyarylene sulfide, and in particular to a continuous production process of polyarylene sulfide resin by dehydration polymerization. Background Art

[0002] Polyarylene sulfide refers to a class of polymers with alternating sulfur and aromatic groups in the main chain structure of the molecule, among which polyphenylene sulfide (PPS) is the most important and typical representative of polyarylene sulfide. As the sixth largest engineering plastic, PPS is widely used in environmental protection, automotive electronics, machinery, chemical industry and aerospace fields. At present, the most commonly used synthesis route of polyphenylene sulfide is the sodium sulfide method. At present, the industrial production equipment for synthesizing PPS by the above method is all intermittent operation. Part of the reaction raw materials are first dehydrated in the reactor. After cooling and adding the remaining reaction raw materials, the reactor is closed and heated for high-temperature polycondensation. After the reaction is completed, the crude product is obtained by cooling, filtering or flash evaporation, and the crude product is purified to obtain the final product. In this production process, the intermittent production process requires repeated loading, heating and cooling, unloading and cleaning of the reactor, which is time-consuming, greatly reduces the production efficiency, and the process stability and reliability are also poor. Moreover, the reaction is greatly affected by the raw material metering system, dehydration temperature rising process, differences between dehydration sulfur loss batches, differences in temperature control during the polymerization process, and the environment. The viscosity of products from different batches fluctuates greatly, and the quality stability is not high.

[0003] At present, a large number of studies have focused on how to achieve continuous production of PPS. For example, US Patents US4060520, US4056515, and US4066632 proposed a continuous production process with multiple kettles in series. The reaction temperature of each kettle is different, and the kettle pressure is continuously reduced from front to back. The pressure difference between adjacent kettles drives the material to flow from front to back. Dehydration and polymerization are carried out in the series kettles. Water and PDCB will be carried out with the distillation tower. The polymerization reaction pressure is controlled by a regulating valve, but this process has the possibility of PPS material being carried out and clogging the heat exchanger.

[0004] Another example is a Chinese patent document with publication number CN 108779253 A, which provides a continuous manufacturing device and method for PAS. The PAS continuous manufacturing device has a holding chamber for accommodating multiple reaction tanks, and an organic amide solvent, a sulfur source, and a dihalogen aromatic compound are supplied to the holding chamber, and a polymerization reaction of the sulfur source and the dihalogen aromatic compound is carried out in the organic amide solvent to form a reaction mixture; the multiple reaction tanks are connected in sequence, and are interconnected via the gas phase, and the reaction mixture moves to each reaction tank in sequence. However, the space utilization rate of the continuous manufacturing device is not high, and because the gas phases are interconnected, the temperature of each reaction tank is difficult to control, and there is a possibility that the reaction mixture enters the next reaction tank before reacting in time, affecting the concentration of the components in the next reaction tank.

[0005] Another example is a Chinese patent document with publication number CN 113667122 A that provides a gradient temperature-controlled continuous condensation method for polyarylene sulfide resin, in which the temperature of each reactor is step-controlled (gradually increased) to adapt to the different progress of the polymerization reaction, and the reaction raw materials are continuously sent to the series-connected kettle or tubular reactors through a metering pump. However, this method does not have a dehydration process, and the raw water introduced in the early stage of the reaction needs to be accurately controlled. During the reaction, the pressure in the reactor needs to be controlled, and the gas phase needs to be depressurized to remove the gas phase washing and purification process, and the emptying pipeline is easily blocked by materials.

[0006] For example, a Chinese patent document with publication number CN 113428841 A provides a continuous dehydration pretreatment method and system for polyarylene sulfide raw materials. The water-containing gas phase evaporated by this method enters each condenser, condenses and recovers the dehydrated water, and the evaporated organic solvent returns to the dehydration pretreatment system, and the non-condensable gas is sent to the gas phase washing and purification system. As the temperature of the dehydration kettle gradually increases, a large amount of NMP and water vapor will evaporate from the kettle in the later stage. Although the NMP solvent is desolventized and recovered, a large amount of NMP and H2S in the dehydration kettle are desorbed, and the NMP / S ratio in the kettle is unbalanced, which ultimately affects the polymerized NMP / S ratio, thereby causing a decrease in the stability of product quality. Summary of the invention

[0007] In view of the above problems existing in the prior art, the present invention discloses a continuous production process of polyarylene sulfide resin dehydration polymerization, the product dehydration and polymerization process is stable, the process is controllable, the investment in related equipment is reduced, the risk of polymerization exothermicity is controllable, and the process stability and reliability are improved.

[0008] The specific technical solutions are as follows:

[0009] A continuous production process for dehydration polymerization of polyarylene sulfide resin, using a sulfur source and a dihalogen aromatic compound as raw materials and an organic amide as a solvent for dehydration and polymerization reaction, specifically comprising the following steps:

[0010] (1) Dehydration: All raw materials except dihalogen aromatic compounds are continuously introduced into N series-connected dehydration reactors, and the N series-connected dehydration reactors are continuously heated by staged temperature control, where N is greater than or equal to 3; the vaporized steam in the N series-connected dehydration reactors is introduced into a distillation tower, and after distillation, the reflux liquid at the bottom of the distillation tower can be refluxed into the N dehydration reactors, and the reflux liquid with a temperature close to that of the dehydration reactor is returned to the dehydration reactor;

[0011] (2) continuously pumping the dehydrated liquid obtained after the treatment in step (1) and the dihalogen aromatic compound into a polymerization reactor, and continuously producing polyarylene sulfide resin after heating polymerization and post-treatment;

[0012] The polymerization reactor is a continuous multi-stage stirring reactor;

[0013] The cross-sectional flow rate of the fluid in the polymerization reactor is (1.7-15.0)×10 -3 m / s.

[0014] The principles in step (1) are as follows:

[0015] Calculate the temperature T of the reflux liquid at the bottom of the distillation tower r and each dehydration reactor temperature T i (i=1~N) the absolute value of the difference, the reflux liquid returns to the dehydration reactor with the smallest absolute value; if the reflux liquid temperature T r and the temperature T of multiple dehydration reactors i If the absolute value of the difference is equal, it enters any one of the multiple dehydration reactors.

[0016] During the dehydration process of polyarylene sulfide resin production, the temperature of the heating source, the reflux rate and the evaporation rate fluctuate due to the boiling of the material in the kettle, which will cause the fluctuation of the temperature at the bottom of the dehydration tower. At this time, if the temperature at the bottom of the tower is low and the material returns to the high-temperature kettle, the H2O / S in the kettle will be high, which will eventually lead to a low polymerization viscosity. The continuous production process of polyarylene sulfide resin disclosed in the present invention uses N dehydration reaction kettles in series in the dehydration stage, and determines the destination of the returned dehydration kettle according to the specific temperature of the reflux liquid at the bottom of the distillation tower in the dehydration process. After the operation of the present invention is adopted, it can be ensured that the water content and NMP composition at the bottom of the tower are close to the composition of the corresponding kettle, avoiding the increase in energy consumption caused by the secondary evaporation of water, extending the dehydration time, ensuring that the water and NMP content in the dehydration kettle fluctuate little, thereby ensuring a stable and efficient dehydration process.

[0017] It is found through experiments that, compared with not adjusting the temperature of the reflux liquid at the bottom of the distillation tower, the polyarylene sulfide resin prepared by the continuous production process of the present invention has a high molecular weight and small fluctuations in molecular weight and melt index (MFR).

[0018] Preferred:

[0019] In step (2), the viscosity and density of the dehydration liquid before entering the polymerization reactor are monitored online and converted into the sulfur source concentration of the dehydration liquid, and finally the theoretical value of the feed flow rate of the dihalogen aromatic compound is converted. By timely adjusting the actual feed flow rate of the dihalogen aromatic compound, the stability of the molar ratio of the dihalogen aromatic compound to the sulfur content in the dehydration liquid in the polymerization reactor is ensured.

[0020] Taking the dihalogen aromatic compound as p-dichlorobenzene (PDCB) as an example, the specific adjustment formula of PDCB feed flow rate can be calculated by the following formula:

[0021]

[0022] n2: molar ratio of PDCB / S

[0023] β: correction coefficient, range 0.5~2

[0024] ρ1: Dehydration liquid density, unit Kg / m 3

[0025] ρ2: PDCB density, unit Kg / m 3

[0026] γ: Dehydration liquid viscosity, unit: Pa·S

[0027] Q 脱水 : Flow rate of dehydration liquid into polymerization reactor, unit: m 3 / h

[0028] Q PDCB : Flow rate of dehydration liquid into polymerization reactor, unit: m 3 / h

[0029] It has been found through experiments that if the molar ratio of the dihalogen aromatic compound to the sulfur content in the dehydration liquid in step (2) is further dynamically adjusted under the premise of adopting the dehydration reflux control in step (1), the polyarylene sulfide resin finally prepared has a higher molecular weight and smaller fluctuations in molecular weight and melt index (MFR).

[0030] Preferred:

[0031] In step (1):

[0032] The heating temperature of the N series-connected dehydration reactors increases gradually from 1 to N and is evenly distributed between 90 and 210°C;

[0033] Further preferred:

[0034] N = 3;

[0035] The temperature of the first dehydration reactor is T1, 90℃≤T1<130℃;

[0036] The temperature of the second dehydration reactor is T2, 130℃≤T2<170℃;

[0037] The temperature of the third dehydration reactor is T3, 170°C≤T3≤210°C.

[0038] Further optimization:

[0039] The temperature of the first dehydration reactor is T1, 110℃≤T1<130℃;

[0040] The temperature of the second dehydration reactor is T2, 160℃≤T2<170℃;

[0041] The temperature of the third dehydration reactor is T3, 200°C≤T3≤210°C.

[0042] Most preferably:

[0043] T1=130℃, T2=170℃, T3=210℃.

[0044] It is found through experiments that, with the optimization of the temperature of each dehydration reactor, the molecular weight of the polyarylene sulfide resin finally prepared is higher, and the fluctuation of the molecular weight and the melt index (MFR) is smaller.

[0045] Preferably, the top temperature of the distillation tower is controlled to be close to the boiling point of water to ensure that more than 99.9% of the solvent removed from the top of the distillation tower is water.

[0046] In step (1):

[0047] The sulfur source is selected from sodium sulfide aqueous solution and / or sodium hydrosulfide aqueous solution, and the concentration is 30-60wt%.

[0048] The dihalogen aromatic compound is selected from one or more of p-dihalobenzene, o-dihalobenzene, m-dihalobenzene, dihalotoluene, dihalonaphthalene, dihalobiphenyl, and the like. Halogen atoms refer to fluorine, chlorine, bromine, and iodine atoms, and two or more halogen atoms in the dihalogen aromatic compound may be the same or different. In terms of reactivity, p-dihalobenzene, m-dihalobenzene, and a mixture of the two are preferred, and p-dichlorobenzene is further preferred.

[0049] The organic amide is selected from one or more of N,N-dimethylformamide, N,N-dimethylacetamide, N-alkyl caprolactam, N-methyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, and hexamethylphosphoric acid triamide; preferably N-methyl-2-pyrrolidone.

[0050] In step (2), the flow ratio of the dehydrating liquid and the dihalogen aromatic compound is controlled so that the molar ratio n2 of the dihalogen aromatic compound to the sulfur content in the dehydrating liquid is 0.9 to 1.3, preferably 1.00 to 1.08; more preferably 1.02 to 1.05.

[0051] In the present invention, the polymerization reactor is a continuous multi-stage stirred reactor, preferably a vertical type. In the polymerization stage, by adopting a vertical continuous reactor, the liquid material is gradually polymerized in different partitions, flows upward, the temperature gradually rises, and finally the material is flashed out from the top. By stably controlling the polymerization temperature at different stages and controlling the gas phase pressure through flash evaporation linkage, the viscosity of the product can be ensured to be stable.

[0052] The continuous multi-stage stirred reactor has a chamber diameter of 50 to 500 mm and a height of 10 to 500 mm for each stage, preferably 300 mm in diameter and 100 mm in height, with a total of more than 10 stages and less than 50 stages, preferably 20 stages of reactors.

[0053] The polymerization reactor is divided into a front section, a middle section and a rear section according to the reaction process;

[0054] The front stage is heated to 160-210° C. and the temperature is controlled by hot oil; in the front stage, the conversion rate of the dihalogen aromatic compound is 0-30%.

[0055] The middle section is heated to 210-240° C. and the temperature is controlled by cold oil; in the middle section, the conversion rate of the dihalogen aromatic compound is 30-90%.

[0056] The latter stage is heated to 240-270° C. and the temperature is controlled by hot oil; in the latter stage, the conversion rate of the dihalogen aromatic compound is 90-100%.

[0057] The pressure in the polymerization reactor is 0.8-2.5 MPa; preferably, it is controlled at 1.0-1.5 MPa.

[0058] The reactor is miniaturized, and compared with a single large reactor, the feed per unit time is reduced, the total number of sulfur moles per unit time is reduced, and the absolute heat release is reduced under the same reaction heat per unit mole of sulfur source. The introduction of a cold medium can easily transfer the heat released by the system, and the entire heat release process is controllable and safer. The reactor pressure is controlled by the outlet regulating valve, which is higher than the saturated vapor pressure of NMP, water and PDCB at this temperature, to ensure that NMP, water and PDCB are not vaporized, thereby reducing the risk of precipitation of PPS dissolved in the solvent, ensuring the stable progress of the polymerization reaction, and at the same time, the material is discharged at a high pressure and temperature. The whole process has high continuity, strong reliability, and improved operability. At the same time, the energy loss in the cooling process at the end of the polymerization is eliminated, which saves more energy consumption and has higher economic benefits.

[0059] The cross-sectional flow rate of a fluid in a polymerization reactor refers to the speed at which the fluid passes through a certain cross-section (such as the cross-section of a pipeline), which is calculated by dividing the flow rate by the cross-sectional area of ​​the reactor barrel.

[0060] The test found that if the cross-sectional flow rate is too small, the salt particles will settle and the reaction cannot proceed normally. If the flow rate is too large, the polymerization reaction residence time is short, the reaction is not complete, and the molecular weight is low.

[0061] Preferably, the cross-sectional flow rate of the fluid in the polymerization reactor is (2.7-5.0)×10 -3 m / s; more preferably (3.0-4.0)×10 -3 m / s.

[0062] The stirring speed of the polymerization reactor is greater than 30 rpm, preferably greater than 50 rpm, such as 50-80 rpm.

[0063] The experiment found that if the stirring speed is too slow and the rising velocity of the polymerization liquid is not enough, the NaCl crystals will settle to the bottom of the polymerization reactor. -3 When the rising flow rate of the polymerization liquid is less than m / s, the NaCl crystals will settle to the bottom of the polymerization reactor, resulting in blockage, which will prevent the reaction from proceeding normally. At this time, a regulating valve for discharging NaCl crystals can be added to the bottom of the polymerization reactor. When the solids at the bottom accumulate to a certain level, the valve can be opened to continuously discharge solid NaCl by monitoring the density change to a certain value, and at the same time, the sodium chloride particles are filtered out to prevent bottom blockage. After the solid-liquid separation of the discharged solid NaCl, it is pumped back into the bulk polymerization system to continue the reaction. Since the filtration equipment involves high-temperature and high-pressure filtration, the equipment has harsh operating conditions and the filter plate is prone to blockage. Under normal circumstances, only by adjusting the rising flow rate of the polymerization liquid and the stirring speed, the effect of preventing NaCl crystals from depositing at the bottom can be achieved, thereby reducing the frequency of use of the filtration equipment.

[0064] In step (2), the post-treatment includes flash drying, purification and drying.

[0065] Compared with the prior art, the present invention has the following advantages:

[0066] The present invention discloses a continuous production process of polyarylene sulfide resin dehydration polymerization. By adopting N dehydration reactors connected in series, and further setting the principle that the reflux liquid with a temperature close to that of the dehydration reactor returns to the dehydration reactor, the dehydration process is ensured to be efficient, and the water in the reflux reactor is prevented from evaporating again, thereby saving energy consumption. The dehydration tower adopts the gas-liquid contact mass transfer principle of the distillation tower, and controls the top temperature of the dehydration tower to be close to the boiling point of water through reflux, ensuring that the top composition is water, and the NMP solvent is not taken out, thereby reducing the wastewater COD and the burden of the solvent recovery system. In combination with the dynamic adjustment of the molar ratio of the dihalogen aromatic compound to the sulfur content in the dehydration liquid during the polymerization reaction, under the synergistic effect of the two, the polyarylene sulfide resin finally prepared has a higher molecular weight and smaller fluctuations in molecular weight and melt index (MFR).

[0067] The continuous production process disclosed in the present invention also adopts a continuous polymerization reactor with a special structure, which is divided into three sections: front, middle and back. Taking the dihalogen aromatic compound as PDCB as an example, the front section is controlled by hot oil at a temperature of 160-210°C, and the PDCB conversion rate is 0-30%, the middle section is controlled by cold oil at a temperature of 210-240°C, and the PDCB conversion rate is 30-90%, and the back section is controlled by hot oil at a temperature of 240-270°C, and the PDCB conversion rate is 90-100%, and the pressure in the reactor is controlled by an outlet regulating valve. The reactor is miniaturized, and compared with a single large reactor, the feed per unit time is reduced, the total sulfur mol of the reaction per unit time is reduced, and the absolute heat release is reduced under the condition that the reaction heat per unit mol of sulfur source is the same. The introduction of a cold medium can easily transfer the heat released by the system, and the entire heat release process is controllable and safer. The reactor pressure is controlled by the outlet regulating valve, which is higher than the saturated vapor pressure of NMP, water and PDCB at this temperature, so as to ensure that NMP, water and PDCB are not vaporized, thereby reducing the risk of precipitation of PPS dissolved in the solvent and ensuring the stable polymerization reaction. At the same time, the material is discharged and flash evaporated at a high pressure and temperature. The whole process has high continuity, strong reliability and improved operability. At the same time, the energy loss in the cooling process at the end of the polymerization is eliminated, which saves more energy consumption and has higher economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1 This is a flow chart of the continuous production process of dehydration polymerization of polyarylene sulfide resin disclosed in Example 1. DETAILED DESCRIPTION

[0069] In order to further understand the present invention, the present invention is described in detail below in conjunction with the embodiments and drawings, but the present invention is not limited to these embodiments. Non-essential improvements and adjustments made by technicians in this field under the core guiding idea of ​​the present invention still fall within the scope of protection of the present invention.

[0070] Figure 1 The present invention is a flow chart of the continuous production process of polyarylene sulfide resin by dehydration polymerization disclosed in Example 1 of the present invention, which includes three dehydration reactors, a distillation tower and a continuous multi-stage stirred reactor connected in series.

[0071] The three dehydration reactors are connected in series in sequence, and the raw materials are continuously introduced into the first reactor through a separate flow meter. The three dehydration reactors are also connected to the distillation towers respectively, and the distillate at the bottom of the distillation tower can be refluxed into the three dehydration reactors. Among them, the dotted line is the interlocking of the distillate temperature at the bottom of the distillation tower and the two three-way valves, which is used to control the reflux of the distillate to the corresponding dehydration reactor.

[0072] The continuous multi-stage stirred reactor is a vertical reactor, which is divided into a front section, a middle section and a rear section from bottom to top according to the reaction process, wherein the front section uses hot oil to control the temperature, the middle section uses cold oil to control the temperature, and the rear section uses hot oil to control the temperature. The vertical continuous multi-stage stirred reactor used in this embodiment has a total of 20 reactors, each reactor chamber has a height of 100 mm, a diameter of 300 mm, and an equivalent flow diameter at the minimum cross section of 65 mm.

[0073] A plurality of feed valves and a discharge valve are arranged at the bottom of the multi-stage stirred reactor; the discharge valve can continuously discharge the high-temperature slurry at the bottom of the reactor, and the NaCl solid is separated and discharged by the NaCl filter to prevent the bottom of the reactor from being blocked. At the same time, the filtrate containing PPS is pumped back into the polymerization system to continue the reaction.

[0074] Example 1

[0075] In three 100L dehydration reactors connected in series, 19.82kg / h (200.0mol / h) of N-methylpyrrolidone, 8.33kg / h (100.0mol / h) of 48wt% sodium hydroxide aqueous solution, 11.93kg / h (100.0mol / h) of 47wt% sodium hydrosulfide aqueous solution, and 3.72kg / h of C5 fatty acid sodium were continuously added. The temperature T1 of the first dehydration reactor was controlled at 130°C, the temperature T2 of the second dehydration reactor was controlled at 170°C, and the temperature T3 of the third dehydration reactor was controlled at 210°C. The reflux temperature of the distillation tower was controlled at 103.5°C, the distillate output flow rate was 10.00kg / h (99.9% water content), and the dehydration was continued. The reflux liquid at the bottom of the distillation tower was adjusted to the direction of the reflux kettle according to the change of the bottom temperature of the distillation tower. When the reflux liquid temperature T r ≤150℃, reflux to the first dehydration kettle. When the reflux liquid temperature is 150℃<T r ≤190℃, reflux to the second dehydration kettle. When the reflux liquid temperature T r When the temperature is higher than 190℃, the third dehydration kettle is refluxed. The materials in the third kettle are pumped into the polymerization reactor at a steady flow rate of 30.08kg / h (sulfur content is 98.0mol / h, water content is 147.0mol / h) by a booster pump. At the same time, p-dichlorobenzene is added to the bottom of the polymerization reactor with an average flow rate of 15.14kg / h (103.0mol / h). PDCB / S=1.051. The PDCB feed flow rate is fixed and does not change with the viscosity and density of the dehydration liquid. The temperature of the front section is controlled at 200℃, the temperature of the middle section is 225℃, the temperature of the rear section is 270℃, and the flow rate of the fluid section is 3.5×10 -3m / s, stirring speed 54rpm, regulating valve controlling polymerization reactor pressure 1.1MPa, the material is dried and washed after flash evaporation, and finally a PPS product of 10.4kg / h is obtained by drying. The reaction is carried out continuously and stably for 16h, and there is no salt particle sedimentation and blockage at the bottom of the polymerization reactor.

[0076] In this embodiment, the NMP content of the distillate taken from the top of the distillation tower during the dehydration process is 0.1%; the final product prepared continuously for 16 hours totals 166 kg, and samples are taken every 4 hours. Each test shows that the MFR is 1100±70g / 10min, the weight average molecular weight is 32000±500, and the ash content is 0.51wt%. The fluctuations of MFR and molecular weight are within the allowable range.

[0077] Example 2

[0078] The preparation process is basically the same as that in Example 1, except that the PDCB feed flow rate is dynamically adjusted with the flow rate, viscosity and density of the dehydration liquid into the polymerization reactor. The instantaneous flow rate of PDCB is adjusted by a regulating valve, and the interlocking flow setting value of the regulating valve is calculated by the online density and viscosity values ​​and the dehydration liquid flow rate.

[0079] According to the test, the reaction in this embodiment was carried out continuously and stably for 16 hours, and there was no salt particle settling and clogging at the bottom of the polymerization reactor.

[0080] In this embodiment, the NMP content of the distillate taken out from the top of the distillation tower during the dehydration process is 0.1%; the final product prepared continuously for 16 hours is 166 kg in total, and the sample is taken every 4 hours. The MFR of each test is 1200±10g / 10min, the weight average molecular weight is 31800±100, and the ash content is 0.49wt%. The fluctuations of MFR and molecular weight are within the allowable range.

[0081] Example 3

[0082] In three 100L dehydration reactors connected in series, 19.82kg / h (200.0mol / h) of N-methylpyrrolidone, 8.33kg / h (100.0mol / h) of 48wt% sodium hydroxide aqueous solution, 11.93kg / h (100.0mol / h) of 47wt% sodium hydrosulfide aqueous solution, and 3.72kg / h of C5 fatty acid sodium were continuously added. The temperature T1 of the first dehydration reactor was controlled at 110°C, the temperature T2 of the second dehydration reactor was controlled at 160°C, and the temperature T3 of the third dehydration reactor was controlled at 210°C. The reflux of the distillation tower controlled the top temperature of the distillation tower to 103.5°C, the distillate output flow rate was 10.00kg / h (water content 99.9%), and dehydration was continued. The reflux liquid at the bottom of the distillation tower adjusted the direction of the reflux kettle according to the change of the bottom temperature of the distillation tower. When the reflux liquid temperature T r≤135℃, reflux to the first dehydration kettle. When the reflux liquid temperature is 135℃<T r ≤185℃, reflux to the second dehydration kettle. When the reflux liquid temperature T r When the temperature is higher than 185℃, the third dehydration kettle is refluxed. The materials in the third kettle are pumped into the polymerization reactor by a booster pump at a flow rate of 30.08kg / h (the amount of sulfur is 98.0mol / h, the amount of water is 147.0mol / h). At the same time, paradichlorobenzene is added to the bottom of the polymerization reactor with an average flow rate of 15.14kg / h (103.0mol / h). PDCB / S=1.051. The PDCB feed flow rate is dynamically adjusted with the flow rate, viscosity and density of the dehydration liquid into the polymerization reactor. The instantaneous flow rate of PDCB is adjusted by a regulating valve. The interlocking flow setting value of the regulating valve is calculated by the online density and viscosity values ​​and the flow rate of the dehydration liquid. The temperature of the front section is controlled at 200℃, the temperature of the middle section is 225℃, the temperature of the rear section is 270℃, and the flow rate of the fluid section is 3.5×10 -3 m / s, stirring speed 54rpm, regulating valve controlling polymerization reactor pressure 1.1MPa, the material is dried after flash evaporation, washed, and dried to finally obtain PPS product 10.4kg / h, the reaction is carried out continuously and stably for 16h, and there is no salt particle sedimentation and blockage at the bottom of the polymerization reactor.

[0083] In this embodiment, the NMP content of the distillate taken out from the top of the distillation tower during the dehydration process is 0.1%; the final product prepared continuously for 16 hours is 166 kg in total, and the sample is taken every 4 hours. The MFR of each test is 1200±20g / 10min, the weight average molecular weight is 31700±150, and the ash content is 0.48wt%. The fluctuations of MFR and molecular weight are within the allowable range.

[0084] Example 4

[0085] In three 100L dehydration reactors connected in series, 19.82kg / h (200.0mol / h) of N-methylpyrrolidone, 8.33kg / h (100.0mol / h) of 48wt% sodium hydroxide aqueous solution, 11.93kg / h (100.0mol / h) of 47wt% sodium hydrosulfide aqueous solution, and 3.72kg / h of C5 fatty acid sodium were continuously added. The temperature T1 of the first dehydration reactor was controlled at 130°C, the temperature T2 of the second dehydration reactor was controlled at 170°C, and the temperature T3 of the third dehydration reactor was controlled at 210°C. The reflux of the distillation tower controlled the top temperature of the distillation tower to 103.5°C, the distillate output flow rate was 10.00kg / h (99.9% water content), and the dehydration was continued. The reflux liquid at the bottom of the distillation tower adjusted the direction of the reflux kettle according to the change of the bottom temperature of the distillation tower. When the reflux liquid temperature T r ≤150℃, reflux to the first dehydration kettle. When the reflux liquid temperature is 150℃<Tr ≤190℃, reflux to the second dehydration kettle. When the reflux liquid temperature T r When the temperature is higher than 190℃, the third dehydration is refluxed. The materials in the third kettle are pumped into the polymerization reactor by a booster pump at a flow rate of 30.08kg / h (the amount of sulfur is 98.0mol / h, the amount of water is 147.0mol / h). At the same time, p-dichlorobenzene is added to the bottom of the polymerization reactor with an average flow rate of 14.8kg / h (100.7mol / h). PDCB / S=1.027. The PDCB feed flow rate is adjusted dynamically with the flow rate, viscosity and density of the dehydration liquid into the polymerization reactor. The instantaneous flow rate of PDCB is adjusted by a regulating valve. The interlocking flow setting value of the regulating valve is calculated by the online density and viscosity values ​​and the flow rate of the dehydration liquid. The temperature of the front section is controlled at 200℃, the temperature of the middle section is 225℃, the temperature of the rear section is 270℃, and the flow rate of the fluid section is 3.47×10 -3 m / s, stirring speed 54rpm, regulating valve controlling polymerization reactor pressure 1.1MPa, the material is dried after flash evaporation, washed, and dried to finally obtain PPS product 10.4kg / h, the reaction is carried out continuously and stably for 16h, and there is no salt particle sedimentation and blockage at the bottom of the polymerization reactor.

[0086] In this embodiment, the NMP content of the distillate taken out from the top of the distillation tower during the dehydration process is 0.1%; the final product prepared continuously for 16 hours is 166 kg in total, and the sample is taken every 4 hours. The MFR of each test is 700±10g / 10min, the weight average molecular weight is 39200±100, and the ash content is 0.42wt%. The fluctuations of MFR and molecular weight are within the allowable range.

[0087] Example 5

[0088] In three 100L dehydration reactors connected in series, 19.82kg / h (200.0mol / h) of N-methylpyrrolidone, 8.33kg / h (100.0mol / h) of 48wt% sodium hydroxide aqueous solution, 11.93kg / h (100.0mol / h) of 47wt% sodium hydrosulfide aqueous solution, and 3.72kg / h of C5 fatty acid sodium were continuously added. The temperature T1 of the first dehydration reactor was controlled at 120°C, the temperature T2 of the second dehydration reactor was controlled at 160°C, and the temperature T3 of the third dehydration reactor was controlled at 200°C. The reflux temperature of the distillation tower was controlled at 103.5°C, the distillate output flow rate was 10.00kg / h (99.9% water content), and dehydration was continued. The reflux liquid at the bottom of the distillation tower adjusted the direction of the reflux kettle according to the change of the bottom temperature of the distillation tower. When the reflux liquid temperature T r ≤140℃, reflux to the first dehydration kettle. When the reflux liquid temperature is 140℃<T r ≤180℃, reflux to the second dehydration kettle. When the reflux liquid temperature Tr When the temperature is higher than 180℃, reflux to the third dehydration reactor. The materials in the third kettle are pumped into the polymerization reactor by a booster pump at a flow rate of 31.42kg / h (the amount of sulfur is 98.0mol / h, the amount of water is 162mol / h). At the same time, paradichlorobenzene is added to the bottom of the polymerization reactor with an average flow rate of 15.14kg / h (103.0mol / h). PDCB / S=1.051. The PDCB feed flow rate is dynamically adjusted with the flow rate, viscosity and density of the dehydration liquid into the polymerization reactor. The instantaneous flow rate of PDCB is adjusted by a regulating valve. The interlocking flow setting value of the regulating valve is calculated by the online density and viscosity values, and the flow rate of the dehydration liquid. The temperature of the front section is controlled at 200℃, the temperature of the middle section is 225℃, the temperature of the rear section is 270℃, and the flow rate of the fluid section is 3.51×10 -3 m / s, stirring speed 54rpm, regulating valve controlling polymerization reactor pressure 1.3MPa, the material is dried after flash evaporation, washed, and dried to finally obtain PPS product 10.4kg / h, the reaction is carried out continuously and stably for 16h, and there is no salt particle sedimentation and blockage at the bottom of the polymerization reactor.

[0089] In this embodiment, the NMP content of the distillate taken out from the top of the distillation tower during the dehydration process is 0.1%; the final product prepared continuously for 16 hours is 166 kg in total, and the sample is taken every 4 hours. The MFR of each test is 1400±20g / 10min, the weight average molecular weight is 29000±150, and the ash content is 0.48wt%. The fluctuations of MFR and molecular weight are within the allowable range.

[0090] Example 6

[0091] In three 100L dehydration reactors connected in series, 15.86kg / h (160.0mol / h) of N-methylpyrrolidone, 6.66kg / h (80.0mol / h) of 48wt% sodium hydroxide aqueous solution, 9.54kg / h (80.0mol / h) of 47wt% sodium hydrosulfide aqueous solution, and 2.98kg / h of C5 fatty acid sodium were continuously added. The temperature T1 of the first dehydration reactor was controlled at 130°C, the temperature T2 of the second dehydration reactor was controlled at 170°C, and the temperature T3 of the third dehydration reactor was controlled at 210°C. The reflux of the distillation tower controlled the top temperature of the distillation tower to 103.5°C, the distillate output flow rate was 8.00kg / h (99.9% water content), and the dehydration was continued. The reflux liquid at the bottom of the distillation tower adjusted the direction of the reflux kettle according to the change of the bottom temperature of the distillation tower. When the reflux liquid temperature T r ≤150℃, reflux to the first dehydration kettle. When the reflux liquid temperature is 150℃<T r ≤190℃, reflux to the second dehydration kettle. When the reflux liquid temperature T rWhen the temperature is higher than 190℃, the third dehydration kettle is refluxed. After dehydration, the flow rate into the polymerization reactor is adjusted according to the viscosity and density. The materials in the third kettle are pumped into the polymerization reactor by a booster pump at a flow rate of 23.8kg / h (the amount of sulfur is 77.54mol / h, and the amount of water is 116.31mol / h). At the same time, p-dichlorobenzene is added to the bottom of the polymerization reactor. The average flow rate is 12.0kg / h (81.5mol / h), PDCB / S=1.051, and the instantaneous flow rate of PDCB is adjusted by the regulating valve. The interlocking flow setting value of the regulating valve is calculated by the online density and viscosity values ​​and the flow rate of the dehydration liquid. The temperature of the front section is controlled at 200℃, the temperature of the middle section is 225℃, the temperature of the rear section is 270℃, and the flow rate of the fluid section is 2.7×10 -3 m / s, stirring speed 29rpm, regulating valve controlling reactor pressure 1.1MPa. After 0.5 hours of reaction, salt particles settled at the bottom of the polymerization reactor and the bottom viscosity increased. At this time, the regulating valve at the bottom of the polymerization reactor was opened, the filtering equipment was enabled, and the mother liquor was pumped back into the reactor. The reaction proceeded normally again. The material was dried after flash evaporation, washed, and dried to finally obtain 8.2kg / h of PPS product. The reaction was continuously and stably carried out for 16 hours, and there was no salt particle settling and blockage at the bottom of the polymerization reactor.

[0092] In this embodiment, the NMP content of the distillate taken out from the top of the distillation tower during the dehydration process is 0.1%; the final product prepared continuously for 16 hours is 130 kg in total, and the sample is taken every 4 hours. The MFR of each test is 1500±270g / 10min, the weight average molecular weight is 28500±2000, and the ash content is 0.45wt%. The fluctuations of MFR and molecular weight are within the allowable range.

[0093] Example 7

[0094] In three 100L dehydration reactors connected in series, 28.31kg / h (285.7mol / h) of N-methylpyrrolidone, 11.9kg / h (142.8mol / h) of 48wt% sodium hydroxide aqueous solution, 17.04kg / h (143mol / h) of 47wt% sodium hydrosulfide aqueous solution, and 5.31kg / h of C5 fatty acid sodium were continuously added. The temperature T1 of the first dehydration reactor was controlled at 110°C, the temperature T2 of the second dehydration reactor was controlled at 160°C, and the temperature T3 of the third dehydration reactor was controlled at 210°C. The reflux of the distillation tower controlled the top temperature of the distillation tower to 103.5°C, the distillate output flow rate was 10.00kg / h (99.9% water content), and the dehydration was continued. The reflux liquid at the bottom of the distillation tower adjusted the direction of the reflux kettle according to the change of the bottom temperature of the distillation tower. When the reflux liquid temperature T r ≤135℃, reflux to the first dehydration kettle. When the reflux liquid temperature is 135℃<T r≤185℃, reflux to the second dehydration kettle. When the reflux liquid temperature T r When the temperature is higher than 185℃, the third dehydration kettle is refluxed. The materials in the third kettle are pumped into the polymerization reactor by a booster pump at a flow rate of 44.37kg / h (sulfur content is 140.0mol / h, water content is 210.0mol / h). At the same time, paradichlorobenzene is added to the bottom of the polymerization reactor with an average flow rate of 21.6kg / h (147.1mol / h). PDCB / S=1.051. The PDCB feed flow rate is dynamically adjusted with the flow rate, viscosity and density of the dehydration liquid into the polymerization reactor. The instantaneous flow rate of PDCB is adjusted by a regulating valve. The interlocking flow setting value of the regulating valve is calculated by the online density and viscosity values ​​and the flow rate of the dehydration liquid. The temperature of the front section is controlled at 200℃, the temperature of the middle section at 225℃, the temperature of the rear section at 270℃, and the flow rate of the fluid section at 5.0×10 -3 m / s, stirring speed 32rpm, regulating valve controlling polymerization reactor pressure 1.1MPa, the material is dried after flash evaporation, washed, and dried to finally obtain PPS product 14.85kg / h, the reaction is carried out continuously and stably for 16h, and there is no salt particle sedimentation and blockage at the bottom of the polymerization reactor.

[0095] In this embodiment, the NMP content of the distillate taken out from the top of the distillation tower during the dehydration process is 0.1%; the final product prepared continuously for 16 hours is 237 kg in total, and the sample is taken every 4 hours. The MFR of each test is 1950±100g / 10min, the weight average molecular weight is 23000±150, and the ash content is 0.52wt%. The fluctuations of MFR and molecular weight are within the allowable range.

[0096] Comparative Example 1

[0097] The preparation process is basically the same as that in Example 1, except that the reflux liquid at the bottom of the distillation tower is not adjusted as the temperature at the bottom of the distillation tower changes, but is refluxed to the third dehydration reactor.

[0098] In this comparative example, the NMP content of the distillate taken out from the top of the distillation tower during the dehydration process was 0.1%; the final product prepared continuously for 16 hours totaled 166 kg, and samples were taken every 4 hours. The MFR of each test was 1830±1000g / 10min, the weight average molecular weight was 25000±5000, and the ash content was 0.52wt%. The MFR and molecular weight fluctuated seriously.

[0099] Comparative Example 2

[0100] The preparation process is basically the same as that in Example 2, except that the reflux liquid at the bottom of the distillation tower is not adjusted as the temperature at the bottom of the distillation tower changes, but is refluxed to the third dehydration reactor.

[0101] In this comparative example, the NMP content of the distillate taken out from the top of the distillation tower during the dehydration process was 0.1%; the final product prepared continuously for 16 hours totaled 166 kg, and samples were taken every 4 hours. The MFR of each test was 1200±110g / 10min, the weight average molecular weight was 31500±1000, and the ash content was 0.47wt%. The MFR and molecular weight fluctuated greatly.

[0102] Comparative Example 3

[0103] In three 100L dehydration reactors connected in series, 15.86kg / h (160.0mol / h) of N-methylpyrrolidone, 6.66kg / h (80.0mol / h) of 48wt% sodium hydroxide aqueous solution, 9.54kg / h (80.0mol / h) of 47wt% sodium hydrosulfide aqueous solution, and 2.98kg / h of C5 fatty acid sodium were continuously added. The temperature T1 of the first dehydration reactor was controlled at 130°C, the temperature T2 of the second dehydration reactor was controlled at 170°C, and the temperature T3 of the third dehydration reactor was controlled at 210°C. The distillation tower reflux controlled the distillation tower top temperature at 103.5°C, and the distillate extraction flow rate was 8.00kg / h (99.9% water content). Dehydration was continued, and the reflux liquid at the bottom of the distillation tower was not adjusted with the reactor temperature, but was refluxed to the third dehydration reactor. The flow rate into the polymerization reactor after dehydration was adjusted with viscosity and density. The material in the third kettle is pumped into the polymerization reactor by a booster pump at a flow rate of 23.8 kg / h (sulfur content is 77.54 mol / h, water content is 116.31 mol / h). At the same time, p-dichlorobenzene is added to the bottom of the polymerization reactor at an average flow rate of 12.0 kg / h (81.5 mol / h). PDCB / S=1.051. The instantaneous flow rate of PDCB is adjusted by a regulating valve. The interlocking flow setting value of the regulating valve is calculated by the online density and viscosity values ​​and the flow rate of the dehydrating liquid. The temperature of the front section is controlled at 200°C, the temperature of the middle section is 225°C, the temperature of the rear section is 270°C, and the flow rate of the fluid section is 2.8×10 -3 m / s, stirring speed 18rpm, regulating valve control reactor pressure 1.1MPa. After a period of reaction, salt particles settle at the bottom of the polymerization reactor, causing blockage, and the reaction cannot proceed normally. In this comparative example, the NMP content of the distillate extracted from the top of the distillation tower during the dehydration process is 0.1%.

[0104] Comparative Example 4

[0105] In three 100L dehydration reactors connected in series, 59.46kg / h (600.0mol / h) of N-methylpyrrolidone, 24.99kg / h (300.0mol / h) of 48wt% sodium hydroxide aqueous solution, 35.79kg / h (300.0mol / h) of 47wt% sodium hydrosulfide aqueous solution, and 11.16kg / h of C5 fatty acid sodium were continuously added. The temperature T1 of the first dehydration reactor was controlled at 130°C, the temperature T2 of the second dehydration reactor was controlled at 170°C, and the temperature T3 of the third dehydration reactor was controlled at 210°C. The distillation tower reflux controlled the distillation tower top temperature at 103.5°C, the distillate extraction flow rate was 30.00kg / h (99.9% water content), and the dehydration was continued. The reflux liquid at the bottom of the distillation tower was not adjusted with the reactor temperature, and all refluxed to the third dehydration reactor. After the dehydration, the flow rate into the polymerization reactor was adjusted with the viscosity and density. The materials in the third kettle are pumped into the polymerization reactor by a booster pump at a flow rate of 89.25 kg / h (sulfur content is 290.8 mol / h, water content is 436.2 mol / h), and 45 kg / h (306.1 mol / h) of p-dichlorobenzene is added to the bottom of the polymerization reactor at the same time. PDCB / S=1.051, PDCB instantaneous flow rate is adjusted by a regulating valve, and the interlocking flow setting value of the regulating valve is calculated by the online density and viscosity values ​​and the dehydration liquid flow rate. The front section temperature is controlled at 200°C, the middle section temperature at 225°C, the rear section temperature at 270°C, and the fluid cross-sectional flow rate is 1×10 -2 m / s, stirring speed 54rpm, regulating valve controlling reactor pressure 1.1MPa, the material is dried and washed after flash evaporation, and finally the PPS product 29.7kg / h is obtained by drying. The reaction is carried out continuously and stably for 16h, and there is no salt particle sedimentation and blockage at the bottom.

[0106] In this comparative example, the NMP content of the distillate taken out from the top of the distillation tower during the dehydration process was 0.1%; the final product prepared continuously for 16 hours totaled 4900 kg, and samples were taken every 4 hours. The MFR of each test was 2000±200g / 10min, the weight average molecular weight was 22000±1000, and the ash content was 0.45wt%. The MFR and molecular weight fluctuated greatly.

[0107] Comparative Example 5

[0108] In three 100L dehydration reactors connected in series, 6.54kg / h (66.0mol / h) of N-methylpyrrolidone, 2.75kg / h (33.0mol / h) of 48wt% sodium hydroxide aqueous solution, 3.94kg / h (33.0mol / h) of 47wt% sodium hydrosulfide aqueous solution, and 1.23kg / h of C5 fatty acid sodium were continuously added. The temperature T1 of the first dehydration reactor was controlled at 130°C, the temperature T2 of the second dehydration reactor was controlled at 170°C, and the temperature T3 of the third dehydration reactor was controlled at 210°C. The reflux of the distillation tower controlled the top temperature of the distillation tower to 103.5°C, the distillate output flow rate was 10.00kg / h (99.9% water content), and the dehydration was continued. The reflux liquid at the bottom of the distillation tower adjusted the direction of the reflux kettle according to the change of the bottom temperature of the distillation tower. When the reflux liquid temperature T r ≤150℃, reflux to the first dehydration kettle. When the reflux liquid temperature is 150℃<T r ≤190℃, reflux to the second dehydration kettle. When the reflux liquid temperature T r When the temperature is higher than 190℃, the flow rate into the third dehydration kettle is refluxed. After the dehydration is completed, the flow rate into the polymerization reactor is adjusted according to the viscosity and density. The materials in the third kettle are pumped into the polymerization reactor by a booster pump at a flow rate of 9.9kg / h (the amount of sulfur is 32.25mol / h, and the amount of water is 48.39mol / h). At the same time, p-dichlorobenzene is added to the bottom of the polymerization reactor. The average flow rate is 5kg / h (33.90mol / h), PDCB / S=1.051, and the instantaneous flow rate of PDCB is adjusted by the regulating valve. The interlocking flow setting value of the regulating valve is calculated by the online density and viscosity values ​​and the flow rate of the dehydration liquid. The temperature of the front section is controlled at 200℃, the temperature of the middle section is 225℃, the temperature of the rear section is 270℃, and the flow rate of the fluid section is 1×10 -3 m / s, stirring speed 54rpm, regulating valve control reactor pressure 1.1MPa. After a period of reaction, salt particles settle at the bottom of the polymerization reactor, causing blockage, and the reaction cannot proceed normally. In this comparative example, the NMP content of the distillate extracted from the top of the distillation tower during the dehydration process is 0.1%.

[0109] Comparative Example 6

[0110] In three 100L dehydration reactors connected in series, 99.10kg / h (1000.0mol / h) of N-methylpyrrolidone, 41.65kg / h (500.0mol / h) of 48wt% sodium hydroxide aqueous solution, 59.65kg / h (500.0mol / h) of 47wt% sodium hydrosulfide aqueous solution, and 18.6kg / h of C5 fatty acid sodium were continuously added. The temperature T1 of the first dehydration reactor was controlled at 130°C, the temperature T2 of the second dehydration reactor was controlled at 170°C, and the temperature T3 of the third dehydration reactor was controlled at 210°C. The reflux of the distillation tower controlled the top temperature of the distillation tower to 103.5°C, the distillate production flow rate was 50.00kg / h (water content 99.9%), and dehydration was continued. The reflux liquid at the bottom of the distillation tower adjusted the direction of the reflux kettle according to the change of the bottom temperature of the distillation tower. When the reflux liquid temperature T r ≤150℃, reflux to the first dehydration kettle. When the reflux liquid temperature is 150℃<T r ≤190℃, reflux to the second dehydration kettle. When the reflux liquid temperature T r When the temperature is higher than 190℃, reflux to the third dehydration. After the dehydration, the flow rate into the polymerization reactor is adjusted according to the viscosity and density. The materials in the third kettle are pumped into the polymerization reactor by a booster pump at a flow rate of 150.4kg / h (the amount of sulfur is 490.0mol / h, the amount of water is 735.0mol / h). At the same time, 75kg / h (515.0mol / h) of p-dichlorobenzene is added to the bottom of the polymerization reactor. PDCB / S=1.051. The instantaneous flow rate of PDCB is adjusted by the regulating valve. The interlocking flow setting value of the regulating valve is calculated by the online density and viscosity values, and the flow rate of the dehydration liquid. The temperature of the front section is controlled at 200℃, the temperature of the middle section is 225℃, the temperature of the rear section is 270℃, and the flow rate of the fluid section is 17.5×10 -3 m / s, stirring speed 54rpm, regulating valve controlling reactor pressure 1.1MPa, the material is dried and washed after flash evaporation, and finally the PPS product 52.0kg / h is obtained by drying. The reaction is carried out continuously and stably for 16h, and there is no salt particle sedimentation and blockage at the bottom.

[0111] In this comparative example, the NMP content of the distillate extracted from the top of the distillation tower during the dehydration process was 0.1%; the final product prepared continuously for 16 hours totaled 832 kg, and samples were taken every 4 hours. The weight-average molecular weight was 8000 each time, indicating that the polymerization reaction was incomplete, and the MFR of the sample was too high to be detected, and the ash content was 0.6 wt%.

[0112] Comparative Example 7

[0113] The preparation process is basically the same as that in Example 6, with the only difference being that, after 0.5 hours of reaction, the salt particles at the bottom of the polymerization reactor settle and the bottom viscosity increases. At this time, the bottom regulating valve is not opened and the filtering equipment is not started. Finally, after 1 hour of reaction, the bottom of the reactor is blocked and the reaction stops.

[0114] In this comparative example, the NMP content of the distillate extracted from the top of the distillation tower during the dehydration process was 0.1%.

[0115] Table 1

[0116]

[0117]

[0118] The above is only a specific implementation of the present invention, but the protection scope of the present invention is not limited thereto. The above specific examples are used to illustrate the present invention, which is only used to help understand the present invention and is not used to limit the present invention. A technician in the technical field to which the present invention belongs can also make several simple deductions, deformations, substitutions or combinations based on the concept of the present invention. These deductions, deformations, substitutions or combinations also fall within the scope of the claims of the present invention.

Claims

1. A continuous production process for dehydration polymerization of polyarylene sulfide resin, It is characterized in that The method uses a sulfur source and a dihalogen aromatic compound as raw materials and an organic amide as a solvent to carry out a dehydration and polymerization reaction, which specifically includes the following steps: (1) Dehydration: All raw materials except dihalogen aromatic compounds are continuously introduced into N series-connected dehydration reactors, and the N series-connected dehydration reactors are continuously heated by staged temperature control, where N is greater than or equal to 3; the vaporized steam in the N series-connected dehydration reactors is introduced into a distillation tower, and after distillation, the reflux liquid at the bottom of the distillation tower can be refluxed into the N dehydration reactors, and the reflux liquid with a temperature close to that of the dehydration reactor is returned to the dehydration reactor; (2) continuously pumping the dehydrated liquid obtained after the treatment in step (1) and the dihalogen aromatic compound into a polymerization reactor, and continuously producing polyarylene sulfide resin after heating polymerization and post-treatment; The polymerization reactor is a continuous multi-stage stirring reactor; The cross-sectional flow rate of the fluid in the polymerization reactor is (1.7-15.0)×10 -3 m / s.

2. The continuous production process of polyarylene sulfide resin by dehydration polymerization according to claim 1, It is characterized in that In step (1), the reflux liquid at the bottom of the distillation tower is returned to the dehydration reactor having a temperature close to that of the distillation tower, specifically: Calculate the temperature T of the reflux liquid at the bottom of the distillation tower r and each dehydration reactor temperature T i The absolute value of the difference, i = 1 ~ N, the reflux liquid returns to the dehydration reactor with the smallest absolute value; If the reflux temperature T r and the temperature T of multiple dehydration reactors i If the absolute value of the difference is equal, it enters any one of the multiple dehydration reactors.

3. The continuous production process of polyarylene sulfide resin by dehydration polymerization according to claim 1, It is characterized in that In step (1): The heating temperature of the N series-connected dehydration reactors increases gradually from 1 to N and is evenly distributed between 90 and 210°C; The top temperature of the distillation tower is controlled to be close to the boiling point of water to ensure that more than 99.9% of the solvent removed from the top of the distillation tower is water.

4. The continuous production process of polyarylene sulfide resin by dehydration polymerization according to claim 3, Features: N＝3； The temperature of the first dehydration reactor is T 1 , 90℃≤T 1 <130℃; The temperature of the second dehydration reactor is T 2 , 130℃≤T 2 <170℃; The temperature of the third dehydration reactor is T 3 , 170℃≤T 3 ≤210℃.

5. The continuous production process of polyarylene sulfide resin by dehydration polymerization according to claim 1, It is characterized in that In step (2), the flow ratio of the dehydrating liquid and the dihalogen aromatic compound is controlled so that the molar ratio of the dihalogen aromatic compound to the sulfur content in the dehydrating liquid is 0.9 to 1.

3.

6. The continuous production process of polyarylene sulfide resin by dehydration polymerization according to claim 1, It is characterized in that In step (2): The polymerization reactor is divided into a front section, a middle section and a rear section according to the reaction process; The front section is heated to 160-210°C; The middle section is heated to 210-240° C.; The latter stage is heated to 240-270°C; The pressure inside the polymerization reactor is 0.8-2.5 MPa.

7. The continuous production process of polyarylene sulfide resin by dehydration polymerization according to claim 1, It is characterized in that In step (2): The cross-sectional flow rate of the fluid in the polymerization reactor is (2.7-5.0)×10 -3 m / s; The stirring speed of the polymerization reactor is greater than 30 rpm, preferably greater than 50 rpm.

8. The continuous production process of polyarylene sulfide resin by dehydration polymerization according to claim 1, It is characterized in that In step (2), a discharge valve is provided at the bottom of the polymerization reactor.

9. The continuous production process of polyarylene sulfide resin by dehydration polymerization according to claim 1, It is characterized in that In step (2), the viscosity and density of the dehydration liquid before entering the polymerization reactor are monitored online and converted into the sulfur source concentration of the dehydration liquid, and finally the theoretical value of the feed flow rate of the dihalogen aromatic compound is converted. By timely adjusting the actual feed flow rate of the dihalogen aromatic compound, the molar ratio of the dihalogen aromatic compound to the sulfur content in the dehydration liquid in the polymerization reactor is ensured to be stable.

10. The continuous production process of polyarylene sulfide resin by dehydration polymerization according to claim 1, It is characterized in that In step (2), the post-treatment includes flash drying, purification and drying.

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