阅读说明：本技术 聚芳硫醚树脂的梯度控温连续缩合方法 (Gradient temperature-controlled continuous condensation method of polyarylene sulfide resin ) 是由 刘容 高建平 李晶晶 任冰涛 于 2021-07-20 设计创作，主要内容包括：本发明提供一种聚芳硫醚树脂的梯度控温连续缩合方法,将含硫单体、含氯单体、非质子极性溶剂、催化剂和助剂以一定比例混合,然后以计量泵连续送到串联的釜式反应器或管式反应器中进行反应,并保证物料在不同的反应器中足够的停留时间；通过设定各反应器恒定在不同的温度,或者设定不同管式反应器的温度范围,从而实现缩合反应的温度梯级控制。本发明采用梯度控温来适配聚合反应不同进度,生产分子量集中且稳定的聚芳硫醚树脂；同时多级串联釜式反应器或管式反应器的连续生产工艺可以有效解决物料反复升温降温问题,降低能耗、缩短生产周期,保障了生产过程的安全和稳定可靠。(The invention provides a gradient temperature-control continuous condensation method of polyarylene sulfide resin, which comprises the steps of mixing a sulfur-containing monomer, a chlorine-containing monomer, an aprotic polar solvent, a catalyst and an auxiliary agent in a certain proportion, and then continuously feeding the mixture into a kettle-type reactor or a tubular reactor which are connected in series by a metering pump for reaction, and ensuring the sufficient retention time of materials in different reactors; the temperature gradient control of the condensation reaction is realized by setting the temperature of each reactor to be constant at different temperatures or setting the temperature range of different tubular reactors. The invention adopts gradient temperature control to adapt to different schedules of polymerization reaction, and produces polyarylene sulfide resin with concentrated and stable molecular weight; meanwhile, the continuous production process of the multistage series kettle type reactor or the tubular reactor can effectively solve the problem of repeated temperature rise and temperature reduction of materials, reduce energy consumption, shorten production period and ensure safety, stability and reliability of the production process.)

1. The gradient temperature-control continuous condensation method of polyarylene sulfide resin is characterized in that a sulfur-containing monomer, a chlorine-containing monomer, an aprotic polar solvent, a catalyst and an auxiliary agent are continuously input into each stage of series-connected kettle-type reactor or tubular reactor for temperature-control condensation reaction by a metering pump according to a certain flow rate, and the temperature of the whole condensation reaction is controlled at 150-300 ℃; the polyarylene sulfide resin slurry thus produced is continuously subjected to the subsequent separation and purification steps to obtain a polyarylene sulfide resin.

2. The method for the gradient temperature-controlled continuous condensation of polyarylene sulfide resin according to claim 1, wherein each of the tank reactors connected in series is kept at a different reaction temperature, the materials in each tank reactor are fully mixed and suspended by adjusting the stirring strength of the reaction tanks, and the materials in each reaction tank are conveyed by natural overflow or a pump; the retention time of the materials in each reaction kettle is set according to the requirements of different polyarylene sulfide resins; the gas phases of the kettle reactors connected in series are communicated with each other, and the gas phases are uniformly washed and purified or are independently washed and purified through different gas phase pipelines.

3. The method for the gradient temperature-controlled continuous condensation of polyarylene sulfide resin according to claim 2, wherein when the gas phases of the tank reactors connected in series are connected, the pressure of the condensation reaction is controlled to be 0.1 to 3.0MPa at the same pressure at the operating pressure of each tank reactor.

4. The method for the gradient temperature-controlled continuous condensation of polyarylene sulfide resin according to claim 2, wherein when the gas phase of each of the tank reactors connected in series is separately passed through a gas phase line to each of the independent gas phase washing purification processes, the operating pressure of each of the tank reactors is controlled within the range of 0.1MPa to 3.0 MPa.

5. The method for the gradient temperature-controlled continuous condensation of polyarylene sulfide resin according to claim 1, wherein each of the tubular reactors connected in series is controlled to have a constant temperature in a certain range along the axial direction of the tubular reactor by an external heat exchanger, and has a stable temperature gradient; the material of each tubular reactor connected in series is provided with conveying power by a material conveying pump.

6. The method for the gradient temperature-controlled continuous condensation of polyarylene sulfide resin as claimed in claim 1, wherein different auxiliaries are added to different tank type condensation reactors or different tubular reactors according to the process requirements to adjust the molecular structure or molecular weight of polyarylene sulfide resin.

7. The method for the gradient temperature-controlled continuous condensation of polyarylene sulfide resin according to claim 1, characterized in that:

the sulfur-containing monomer is any one or more of the following: anhydrous sodium sulfide, sodium sulfide containing crystal water, anhydrous sodium hydrosulfide, sodium hydrosulfide aqueous solution, and crystal sodium hydrosulfide;

the chlorine-containing monomer is any one or more of p-dichlorobenzene, p-chlorobenzoic acid, p-chloroaniline, dichlorobiphenyl, dichlorodiphenyl ether, dichlorobenzophenone, dichlorodiphenyl sulfone, dichloropyridine and dichlorodiphenyl ether;

the aprotic polar solvent is any one or more of: n-methylpyrrolidone NMP, hexamethylphosphoric triamide HMPTA and N, N-dimethylformamide DMF, N-dimethylacetamide DMAc, sulfolane CBS, N-methyl-2-imidazolidinone NMI.

8. The method for the gradient temperature-controlled continuous condensation of polyarylene sulfide resin according to claim 1, wherein when the polymer is polyphenylene sulfide having the simplest structure, the sulfur-containing monomer is anhydrous sodium sulfide, sodium sulfide of crystal water, anhydrous sodium hydrosulfide, an aqueous solution of sodium hydrosulfide; the chlorine-containing monomer is p-DCB; the aprotic polar solvent is NMP, HMPTA and CBS;

according to the molar weight, the dosage of the p-DCB is 1.0-1.5 times of the sulfur content; the total mass of NMP is 500-600 g NMP/1mol of sulfur source monomer; the total water content of the system is 1.0-4.5 times of the content of the sulfur source compound.

9. The method for the gradient temperature-controlled continuous condensation of polyarylene sulfide resin according to claim 1, wherein the catalyst is lithium chloride, lithium formate, lithium acetate, lithium propionate, lithium butyrate, lithium hydroxybutyrate, lithium salt of aromatic acid, lithium salt of saturated fatty acid of C10-C20; the dosage of the lithium salt serving as the catalyst is 0.5-1.0 time of the mole number of the sulfur-containing monomer.

10. The method for the gradient temperature-controlled continuous condensation of polyarylene sulfide resin according to claim 1, wherein the auxiliary agent is a carboxylate of an alkali metal, including sodium formate, potassium formate, sodium acetate, potassium acetate, sodium propionate, potassium propionate, sodium butyrate, potassium butyrate, and sodium salt or potassium salt of an aromatic acid having not more than 10 total carbons in the molecule; the dosage of the auxiliary agent is 0.1-0.5 time of the mole number of the sulfur-containing monomer.

Technical Field

The invention belongs to the field of synthesis of organic functional high molecular polymers, and relates to a gradient temperature control continuous condensation method of polyarylene sulfide resin.

Background

The polyarylene sulfide resin is a special high molecular polymer with a molecular main chain of sulfur and an aryl structure which are alternately connected. The polymer generally has the characteristics of excellent high temperature resistance, corrosion resistance and radiation resistance, excellent dimensional stability, excellent electrical insulation performance and the like, and is widely applied to the industrial fields of machining, electronics and electricity, light weight of automobiles, precision manufacturing, aerospace, 3D printing, ecological environmental protection, medicines, pesticides, new energy batteries, electronic information, intelligent communication and the like. The aryl group may be classified into polyarylene sulfide PAS, polyarylene sulfide sulfone (PASs), polyarylene sulfide ketone (PASK), polyarylene sulfide amide (PASA), and the like, according to the difference in the aryl structure, and the aromatic ring structure may further have other substituents such as alkyl group (e.g., methyl, ethyl, propyl, butyl, and the like), carboxyl group, amino group, hydroxyl group, aryl group, alkylacyl group, alkylacyloxy group, benzoyl group, benzoyloxy group, alkylamido group, alkylacyl group, and quaternary ammonium salt group, and the like, thereby imparting other functional effects such as antibacterial property, metal ion chelating property, antibacterial property, coloring property, antistatic property, electric conductivity, and the like to the polyarylene sulfide.

In a general polyarylene sulfide resin, polyphenylene sulfide (PPS), which has the simplest structure, has a main chain structure in which a sulfur atom and a benzene ring are alternately connected, and is a crystalline polymer resin. The high-performance flame-retardant plastic has excellent solvent resistance, corrosion resistance, flame retardance, insulativity and mechanical strength, and is one of special engineering plastics with the most industrial value and application prospect. Currently, para-dichlorobenzene (p-DCB) and sodium sulfide or sodium hydrosulfide are frequently used for pressure polymerization in NMP to generate polyphenylene sulfide resin industrially. The synthesis process is mostly intermittent operation, raw materials containing crystal water sodium sulfide or sodium hydrosulfide, sodium hydroxide solution and partial solvent are heated in a dehydration kettle for dehydration reaction, then the dehydrated materials are cooled and transferred into a high-pressure condensation reaction kettle, raw materials such as p-dichlorobenzene and catalyst are added, the reaction kettle is sealed, the temperature is raised, and the condensation reaction is carried out under the conditions of high temperature and high pressure to obtain the resin slurry. The intermittent condensation process needs repeated heating, cooling and material transfer, has long auxiliary time, thus causing the problems of long material retention time, solvent decomposition and the like, and consumes a large amount of manpower in intermittent production and consumes time in operations of loading, unloading and the like; the temperature rise and temperature drop courses of each batch are inconsistent, the process stability and reliability are poor, the product quality consistency cannot be ensured, and the subsequent purification and refining unit operation, processing application and the like of the resin are influenced; meanwhile, the thermal strain of the process equipment in the repeated heating and cooling processes is frequent, so that the equipment is easily damaged, and the safety of the production process is seriously influenced.

The foreign patent US4060520-A proposes a continuous polyarylene sulfide production process, in which the raw material is fed at 13.5-15.0 Kg/cm in the first reaction zone²Partially polymerizing under the pressure of (1), and then transporting the partially polymerized material to a second reaction area to make the partially polymerized material at 12.0-13.5 Kg/cm²Polymerization was complete under pressure, but the two reactions were kept at the same temperature. Domestic patent CN00116140.7 proposes a method for controlling the conditions of a synthetic process for polyphenylene sulfide production, in particular to continuously injecting a NMP solution containing p-DCB at a low temperature section of a polymerization reaction and simultaneously adjusting the injection rate according to the feedback of the reaction temperature. However, in the patent, other materials are fed intermittently, and the whole process is operated intermittently.

Disclosure of Invention

Aiming at the technical problem, the invention provides a method for continuously synthesizing polyarylene sulfide resin by gradient temperature control, which adopts gradient temperature control to adapt to different progress of polymerization reaction and produces polyarylene sulfide resin with concentrated and stable molecular weight; meanwhile, the continuous production process of the multistage series kettle type reactor or the tubular reactor can effectively solve the problem of repeated temperature rise and temperature reduction of materials, reduce energy consumption, shorten production period and ensure safety, stability and reliability of the production process.

The technical scheme adopted by the invention is as follows:

a process for continuously condensing the polyarylthioether resin by gradient temp control includes proportionally mixing the S-contained monomer, Cl-contained monomer, solvent for condensation reaction, catalyst and assistant, and continuously feeding them to n-stage serial reactor or tubular reactor by metering pump for reaction. The temperature range of the whole polymerization reaction is 150-300 ℃, the temperature of each serially connected kettle type reactor or tubular reactor is a low-temperature reaction zone and a high-temperature reaction zone along the material flowing direction, and the low-temperature section is beneficial to forming small molecules and oligomers; the high temperature section promotes the polymerization of small molecules and oligomers and increases molecular chains. The gradient temperature control of the polymerization reaction is realized by setting each reactor to be constant at different temperatures or setting each tubular reactor to be in different temperature intervals. And after the polymerization reaction is finished, continuously outputting the polyarylene sulfide resin slurry from the last-stage reaction kettle or the tubular reactor, and performing separation and purification procedures to obtain the polyarylene sulfide resin. The whole reaction process is carried out in a closed system, and inert gases such as nitrogen and the like are introduced to replace the air in the reactor before the reaction so as to prevent the solvent from oxidative denaturation.

In the raw material, the sulfur-containing monomer is one or more of anhydrous sodium sulfide, sodium sulfide containing crystal water, anhydrous sodium hydrosulfide, sodium hydrosulfide aqueous solution, crystal sodium hydrosulfide and the like; the chlorine-containing monomer is one or more of p-dichlorobenzene (p-DCB), p-chlorobenzoic acid, p-chloroaniline, dichlorobiphenyl, dichlorodiphenyl ether, dichlorobenzophenone, dichlorodiphenyl sulfone, dichloropyridine, dichlorodiphenyl ether and the like; the aprotic polar solvent is any one or more of N-methylpyrrolidone (NMP), hexamethylphosphoric triamide (HMPTA), N-Dimethylformamide (DMF), N-dimethylacetamide (DMAc), sulfolane (CBS), N-methyl 2-imidazolidinone (NMI), and the like.

When the polymer is polyphenylene sulfide with the simplest structure, the sulfur-containing monomer is preferably anhydrous sodium sulfide, sodium sulfide with crystal water (sodium sulfide nonahydrate, sodium sulfide pentahydrate and sodium sulfide trihydrate), anhydrous sodium hydrosulfide and an aqueous solution of sodium hydrosulfide; the chlorine-containing monomer is preferably p-DCB; preferred aprotic polar solvents are NMP, HMPTA and CBS.

The catalyst is lithium chloride, lithium formate, lithium acetate, lithium propionate, lithium butyrate, lithium hydroxybutyrate, lithium salt of aromatic acid, and C10-C20, especially C12-C18 saturated fatty acid lithium salt.

The auxiliary agent is carboxylate of alkali metal, including sodium formate, potassium formate, sodium acetate, potassium acetate, sodium propionate, potassium propionate, sodium butyrate, potassium butyrate, and sodium salt or potassium salt of aromatic acid whose total carbon number in molecule is not more than 10, specially not more than 7.

The dosage of each material is based on a sulfur source compound, and the dosage of p-DCB is 1.0-1.5 times of the sulfur content (molar weight, the following is all the same); the total mass of NMP is 500-600 g NMP/1mol of sulfur source monomer; the total water content of the system is 1.0-4.5 times of the content of the sulfur source compound; the dosage of the catalyst is 0.5-1.0 time of that of the sulfur source compound; the dosage of the auxiliary agent is 0.1-0.5 time of the mole number of the sulfur-containing monomer.

The catalyst and the auxiliary agent can be added at one time, and can also be added in different stages of reaction kettles or tubular reactors in different times according to the requirements of the process.

Specifically, when a multistage series kettle type reactor is used for continuously carrying out polymerization reaction, the reaction temperature in each stage of reaction kettle connected in series is kept constant at different values to form a certain temperature gradient; liquid heating medium is introduced into each reaction kettle jacket from bottom to top or steam is introduced from top to bottom to adjust the temperature required by the materials in the reaction kettle, so as to realize the control of the temperature gradient. The complete uniform mixing of the slurry in the kettle type reactor is realized through the special stirring blade structure, the kettle accessories and the adjustable stirring strength of the kettle type reactors which are connected in series, thereby achieving the reaction effect similar to a full-mixing kettle.

The gas phases of all the kettle reactors can be communicated with each other, the gas phase washing and purifying process is unified, the operation pressure in all the reaction kettles is kept consistent, and the pressure of the polymerization reaction is controlled to be 0.1-3.0 MPa; or the gas phase of each reaction kettle is subjected to a washing and purifying process through different gas phase pipelines, the operation temperature and the operation pressure in each reaction kettle are different, and the pressure of the polymerization reaction is controlled to be 0.1-3.0 MPa. When the gas phases are mutually communicated and the operation pressure in the reaction kettle is kept consistent, the materials among the reaction kettles can be naturally overflowed and conveyed through the potential difference of the reaction kettles or conveyed through a high-temperature slurry pump; when the gas phase is respectively and independently led to the washing and purifying working procedure, the materials among the reaction kettles are transported by a pump. When the materials are conveyed by utilizing the reaction kettle potential difference natural overflow mode, the materials are directly conveyed to the bottom end in the kettle through a feed inlet guide pipe at the upper part of the reaction kettle, flow out from a discharge outlet at the upper end of the kettle body after certain retention time, and naturally overflow to a next-stage reaction kettle; when the high-temperature slurry pump is used for conveying materials, except the first-stage reaction kettle, the rest materials of each kettle are input into the reaction kettle from the bottom of the reaction kettle by the pump, and are output from the discharge port at the upper end after certain retention time, and the feed port of the first-stage reaction kettle is identical to that of the natural overflow reaction kettle.

When the polyarylene sulfide is continuously polymerized and produced by utilizing a multistage series tubular reactor, the temperature interval of different stages of tubular reactors is set to form the temperature gradient of polymerization reaction; the high-temperature heat conduction oil is reversely conveyed along the material flow direction to the outer jacket of the tubular reactor, the axial temperature of the oil is controlled to be constant in a certain range along the axial direction of the tubular reactor, and the gradient temperature control is realized. The tubular reactor is internally provided with a special flow guide structure and irregularly changed flow channels so as to realize the complex change of the material flow pattern and further realize the sufficient mixing and suspension of materials on different sections along the radial direction. Visual static mixers are arranged among the tubular reactor sections, and different additives can be supplemented through the mixers, so that the flexible production of polyarylene sulfides with different structures is realized; meanwhile, the reaction condition, the formation state of the polyarylene sulfide resin and the like can be observed, and the reaction condition can be adjusted in time. The materials in the tubular reactor are provided with conveying power by a high-temperature slurry pump.

The invention is characterized in that:

the condensation reaction temperature of each reaction kettle or each section of tubular reactor can be flexibly adjusted; secondly, the stirring strength of the kettle type reactors connected in series is controlled by designing stirring blades with special structures, so that the materials in the kettles are fully and uniformly mixed; the tubular reactor has a special flow guide structure, and realizes the complex change of material flow pattern, thereby realizing the full mixing and suspension of materials on different sections along the radial direction; thirdly, materials among all the kettle type reactors connected in series are naturally overflowed through potential difference or conveyed to slurry through a high-temperature slurry pump; conveying power is provided among all sections of tubular reactors through a high-temperature slurry pump; the process carries out the polymerization reaction at different temperatures of n sections (n is more than or equal to 2) by adjusting the temperature in all the serially connected fully mixed reaction kettles or tubular reactors, is favorable for realizing prepolymerization, condensation and final polymerization at different temperatures or temperature intervals, improves the conversion rate of monomers, and ensures that the molecular weight of the polymer is concentrated and stable. The polymer slurry obtained by the process can adopt the washing and purifying process technology commonly used in industry to separate the polyarylene sulfide resin and recover the solvent. Compared with the batch polymerization reaction technology generally adopted in the industry at present, the polyarylene sulfide gradient temperature control continuous condensation reaction process has higher production efficiency, more stable and controllable process, better resin quality and better economy.

The invention adopts gradient temperature control to adapt to different schedules of polymerization reaction, and produces polyarylene sulfide resin with concentrated and stable molecular weight; meanwhile, the continuous production process of the multistage series kettle type reactor or the tubular reactor can effectively solve the problem of repeated temperature rise and temperature reduction of materials, reduce energy consumption, shorten production period and ensure safety, stability and reliability of the production process.

Drawings

FIG. 1 is a schematic flow diagram of a production process of a gradient temperature-controlled multi-stage series tank reactor in which the material of example 1 flows to a next-stage reactor through natural overflow;

FIG. 2 is a schematic diagram of a production process of a gradient temperature-controlled multi-stage series tank reactor in which the material of example 1 is conveyed to a next-stage reactor by a high-temperature slurry pump;

FIG. 3 is a schematic diagram of the continuous polyarylene sulfide synthesis process using a gradient temperature-controlled multistage tubular reactor in example 2.

Detailed Description

The specific technical scheme of the invention is explained by combining the attached drawings.

Example 1

As shown in figure 1 or figure 2, polyphenylene sulfide resin is continuously synthesized through gradient temperature control of three-stage series kettle type reactors.

The flow rates of the materials are as follows: 56Kg/h of sulfur-containing monomer sodium hydrosulfide, 176.4Kg/h of chlorine-containing monomer p-dichlorobenzene, 550Kg/h of total weight of NMP, 29.7Kg/h of catalyst lithium chloride and 16.8Kg/h of auxiliary agent sodium acetate. The materials are input into a first reaction kettle according to the flow, the reaction temperature is controlled at 185 ℃, and the retention time is 90 minutes. The material overflows to the second reactor naturally through potential difference, the reaction temperature in the second reactor is controlled at 220 ℃, and the retention time is 150 minutes. And the resin slurry naturally overflows to a third reaction kettle through a potential difference, the reaction temperature is kept at 255 ℃, and the retention time is 190 minutes. The polyphenylene sulfide resin product can be obtained through subsequent solid-liquid separation, washing and purification, the yield can reach 91%, and the weight average molecular weight of the polyphenylene sulfide resin can reach 44251 g/mol.

Example 2

As shown in FIG. 3, the polyarylene sulfide resin is synthesized by gradient temperature control continuous synthesis of three-stage series tubular reactors. The material flow rates were the same as in example 1; the temperature interval of the first-stage tubular reactor is controlled to be 180-190 ℃, and the retention time is 50 minutes. And (3) inputting the mixed solution into a second-stage tubular reactor through a high-temperature slurry pump, wherein the temperature interval of the tubular reactor is controlled to be 215-225 ℃, and the retention time is 90 minutes. And (3) conveying the material to a third-stage tubular reactor through a pump, wherein the temperature interval of the tubular reactor is controlled to be 250-260 ℃, and the retention time is 120 minutes. The final resin yield can reach 95%, and the weight average molecular weight is 49280 g/mol. Compared with the tubular reactor in the example 1, the tubular reactor has no radial concentration gradient of materials and is more uniform in mixing, so that the reaction effect is better, and the required reaction residence time is shorter.