CN117924704A

CN117924704A - Preparation method of sulfone polymer resin

Info

Publication number: CN117924704A
Application number: CN202410050180.8A
Authority: CN
Inventors: 仇伟; 曾伟; 屈亚青; 高雁伟
Original assignee: Wanhua Chemical Group Co Ltd
Current assignee: Wanhua Chemical Group Co Ltd
Priority date: 2024-01-15
Filing date: 2024-01-15
Publication date: 2024-04-26

Abstract

The invention provides a preparation method of sulfone polymer resin. The method comprises the following steps: (1) Uniformly mixing alkali metal salt of bisphenol monomer and dichlorodiphenyl sulfone; (2) Injecting the mixed monomer and the passivation component into a double-screw extruder, and performing reactive extrusion under certain conditions to obtain crude resin; (3) Crushing, washing and drying the crude resin to obtain the finished resin. The invention directly carries out reaction extrusion through the monomer, and completely avoids the use of organic solvents, thereby avoiding various side reactions and solvent recovery treatment problems caused by the use of the organic solvents. The method is simple and easy to implement, has high production efficiency, small equipment occupation area and little three wastes in production, and has higher economic benefit.

Description

Preparation method of sulfone polymer resin

Technical Field

The invention belongs to the field of high polymer synthesis, and particularly relates to a preparation method of sulfone polymer resin.

Background

The sulfone polymer is a high-temperature engineering plastic with outstanding performance and wide application range, and has wide application in the fields of high-end electronics, water treatment, medical consumables, aviation materials and the like.

The preparation method of the sulfone polymer resin generally comprises the steps of gradually polymerizing bisphenol monomers and dichlorodiphenyl sulfone in a strong polar aprotic solvent through nucleophilic reaction to generate a polymer solution, and then obtaining the finished resin through a series of post-treatment procedures such as desalting, precipitation, washing and the like. In the course of polymerization, since a solution polymerization process is employed, various harmful side reactions inevitably occur, organic impurities including dimethylaminobyproducts, cyclic polymers and the like are generated, and the properties of the resin itself are seriously affected. Meanwhile, solution polymerization is limited by the polarity of the solvent and the difficulty of removing byproduct water, a certain amount of water-carrying agent (usually nonpolar aromatic hydrocarbon solvent) needs to be additionally added, the polymerization speed is limited to a certain degree, and the reaction time is long. In addition, the use of the solvent makes the treatment steps of solvent recovery, product purification and the like complicated after the reaction.

Some methods have been reported in the prior art to ameliorate the above drawbacks by making limited measures based on solution polymerization processes. For example, patent CN111072965A finds the optimum concentration range for the polymerization reaction by adjusting the amount of reaction solvent (DMAc) and by changing the order of addition, thereby reducing the amount of cyclic dimer produced; the patent CN111072965A avoids a series of post-treatment problems caused by the use of a solvent with water by increasing the pressure in the kettle to 2-3 MPa; patent CN109354686A adopts a salt forming-polymerization two-step process, and the polymerization is controlled to be carried out in an accurate equimolar ratio, so that the polymerization time is shortened.

However, the above methods are all improved and optimized on the basis of the solvent method, and the essential defects of the solvent method are not fundamentally solved.

The development of a new preparation method of sulfone polymer to essentially solve various defects of the existing solvent method has very important significance.

Disclosure of Invention

The invention provides a preparation method of sulfone polymer resin, which is characterized in that the monomer is directly subjected to reaction extrusion, so that the use of an organic solvent is completely avoided, and various defects of synthesizing the sulfone polymer by a solvent method are avoided.

In order to achieve the purpose of the application, the application provides the following technical scheme:

A method for preparing a sulfone polymer resin comprising the steps of:

(1) Uniformly mixing alkali metal salt of bisphenol monomer and dichlorodiphenyl sulfone monomer;

(2) Injecting the mixed monomer and the passivation component into a double-screw extruder for extrusion to obtain crude resin;

(3) Crushing, washing and drying the crude resin to obtain the resin.

In the step (1) of the present invention, the alkali metal salt of the bisphenol monomer is a compound having the following structural formula:

wherein M is an alkali metal, preferably K, na; r is an organic group comprising isopropyl, sulfonyl, -CH2-, carbonyl, oxygen atom, etc., or directly connected by sigma bonds, preferably isopropyl and sulfonyl;

alkali metal salts of bisphenol monomers are sensitive to moisture and air and are not easy to preserve, and are typically prepared by on-the-fly. Various well-known processes for preparing alkali metal salts of bisphenol monomers are known in the art, and the present invention is not limited to the preparation method and process.

In the step (1) of the present invention, the molar ratio of the alkali metal salt of the bisphenol monomer to the dichlorodiphenyl sulfone monomer is (0.980 to 0.999) to 1, preferably (0.990 to 0.998) to 1. The polymerization degree is automatically terminated due to the excessive chlorine end group in the later stage of the polymerization reaction due to the excessive dichlorodiphenyl sulfone monomer, compared with the excessive bisphenol monomer, the problem that side reaction is increased and the end capping agent is required to be additionally added for end capping can be avoided, and the preparation process is simplified. In addition, by adjusting the molar ratio, the purpose of controlling the molecular weight of the product can be achieved.

In the step (1), the alkali metal salt of the bisphenol monomer and the dichlorodiphenyl sulfone monomer can be mixed in advance and then the mixture is directly fed, or the alkali metal salt of the bisphenol monomer and the dichlorodiphenyl sulfone monomer can be fed respectively when fed by an extruder and mixed in a feeding section of the extruder. The mixing in advance may be performed by conventional mixing equipment such as a countercurrent mixer and the like.

In the step (2) of the present invention, the passivation component is a compound having the following structure:

Wherein, R1 and R2 are the same or different and are respectively selected from benzene rings or saturated alkyl groups with more than 3 carbon atoms, n=1 to 100, preferably n=20 to 70;

Wherein, the passivation component accounts for 1 to 20 percent of the total mass of the material, preferably 5 to 10 percent;

The alkali metal salt of bisphenol monomer has high activity, and directly contacts with dichlorodiphenyl sulfone monomer under high temperature shearing of screw to generate rapid polymerization reaction, and generates a large amount of reaction heat in a short time, which is easy to cause chain transfer, crosslinking and even undesirable side reactions such as polymer coking, and the quality of the obtained product is poor. Therefore, in order to deactivate and slow down the reactivity of the polymerized monomers, a third component with a certain component needs to be added to play a role in delaying the polymerization speed.

The applicant has found through extensive research that the passivation component adopting the structure can effectively relieve the problem of bursting during the reactive extrusion process, and the quality of the final product is not reduced.

In the step (2) of the present invention, the aspect ratio of the twin-screw extruder is (60 to 90): 1, preferably (70 to 80): 1. And, the twin-screw extruder includes a feeding section, a compression section, a polymerization section, and a plasticizing section.

In the step (2), the temperature of the feeding section is 20-60 ℃, and the temperature of the compression section is: the temperature of the polymerization section is 100-140 ℃, and the temperature of the polymerization section is as follows: 200-280 ℃, and the plasticizing section temperature is: 300-320 ℃. When the reactive extrusion is carried out, the solid mixture of alkali metal salt of bisphenol monomer and dichloro diphenyl sulfone monomer is initially mixed and compressed in a feeding section, and monomer is preheated, and in the compression section, the monomers are further compressed to enable solid materials to be in direct contact with each other, and heat generated in the extrusion friction process enables the dichloro diphenyl sulfone monomer to melt and form solid-liquid two phases with the alkali metal salt of bisphenol monomer, so that the prepolymerization reaction occurs. In the polymerization stage, the chain growth process of the prepolymer mainly occurs, and the polymerization degree is continuously increased and the melt viscosity is continuously increased along with the residual monomer access chain links. In the plasticizing section, the polymerization degree and viscosity of the polymer are slightly increased, the reaction monomers are almost completely consumed, the resin melt and byproduct salt and the protection period are mixed with each other in the plasticizing section, and finally, the opaque porous foam-like solid discharge, namely, the crude resin is formed.

It should be noted that in the above step (2) of the present invention, the functions of the feeding section, the compression section, the polymerization section and the plasticizing section are not strictly defined by dividing lines, and the length ratio is not strictly defined, so that the functions of the sections are mutually crossed. By adjusting parameters such as the thread structure, the length proportion and the like of each section, different products with different performances can be obtained.

In the step (2), a reaction inert gas is required to be introduced, wherein the reaction inert gas is nitrogen, carbon dioxide, helium, neon or argon.

As one of the preferable schemes, before the reaction extrusion is implemented, the inner cavity of the screw extruder is replaced by reaction inert gas in advance, so that the extrusion reaction is carried out in the reaction inert gas atmosphere, and a resin product with better transparency and color can be obtained;

As one of the preferred schemes, in the reaction extrusion implementation, the lower flow of reaction inert gas is adopted in the feeding section, the compression section and the polymerization section for protecting the monomer materials, so that the monomer materials are fully mixed, and the higher flow of protecting gas is adopted in the plasticizing section for enabling the polymer to have sufficient air hole quantity and ratio for the subsequent crushing and washing.

In the method, the performance difference of the final resin can be controlled by comprehensively adjusting the technological parameters such as the rotating speed, the feeding speed, the screw temperature, the flow speed of the shielding gas and the like of the extruder, so that products with different types and applications can be prepared.

As one of preferable embodiments, the flow rate of the reaction inert gas in the polymerization stage of the extruder is 0.05 to 0.5L/min, preferably 0.1 to 0.2L/min.

As one of preferable embodiments, the flow rate of the reaction inert gas in the plasticizing section of the extruder is 0.2 to 1.0L/min, preferably 0.5 to 0.8L/min.

In the step (3) of the present invention, the fineness of the crushed crude resin is 200 to 800. Mu.m, preferably 500 to 600. Mu.m. The crushing of the crude resin may be performed by a crushing scheme or apparatus commonly used in the industry, and the present invention is not limited thereto. The crushing purpose is firstly to chop the massive solid materials into fine and uniform powder, so that impurities such as byproduct salt and the like can be removed better in the washing process, and the operation of the subsequent procedures such as conveying, packaging, secondary extrusion and the like is convenient.

In the step (3), the washing liquid is an aqueous solution prepared from one or more of methanol, ethanol, methyl acetate, ethyl acetate, tetrahydrofuran and acetonitrile, and the concentration is 20-70 wt%, preferably 50-60 wt%; the aim of the washing is to wash away residual byproduct salt, residual monomers, micromolecular byproducts and other trace organic impurities in the resin. The water of the washing liquid is used to dissolve the inorganic salts, while the solvent component may extract the above-mentioned organic impurities. It is emphasized that the solvent-free bulk polymerization process is adopted, so that the content of the organic impurities is very small, and the difficulty of meeting the washing requirement is low. The present invention is not particularly limited in terms of washing equipment, temperature, number of times, etc.

In the step (3) of the present invention, pure water is used for the last washing. The purpose of the pure water washing is to further improve the purity of the resin in order to wash out the organic solvent washed in the previous several times.

In the step (3) of the present invention, the resin may be dried by a drying means and equipment commonly used in the industry, and the drying process is not particularly limited.

The invention has at least the following positive effects:

according to the invention, the monomer is directly used for bulk polymerization, so that the use of an organic solvent and various side reactions brought by the organic solvent are avoided, and the product quality is improved;

The invention adopts the method of adding the passivation component, thereby effectively solving the problems of explosion polymerization and side reaction caused by overhigh monomer activity in the reaction extrusion;

the invention adopts the excessive implementation process of the dichloro monomer, avoids the problem that the end capping agent is required to be additionally added for end capping after polymerization is finished, and simplifies the preparation process;

the preparation process of double-screw reaction extrusion is simple and feasible, has high production efficiency, small occupied area, less three wastes and high economic benefit.

Detailed Description

According to the technical scheme, the following examples are given, and the examples are not used for limiting the protection scope of the invention.

GPC test method:

instrument: shimadzu LC-20A liquid chromatograph

The sample preparation method comprises the following steps: 1% DMF solution

The liquid phase testing method comprises the following steps:

instrument: agilent LC-20AD

The sample preparation method comprises the following steps: 1% THF solution, methanol precipitation

Mobile phase: 50% acetonitrile aqueous solution

Main raw material providing channel

Preparation of disodium salt of bisphenol monomer

The present examples of preparation are provided for reference only and are in no way intended to limit the scope of application of the invention.

50G of xylene was poured into a reactor connected to a condenser, a water separator, a mechanical stirrer and a thermometer, and 228.3g of bisphenol A and 80.5g of sodium hydroxide were poured while stirring. The temperature was raised to 120℃with vigorous stirring to thoroughly disperse the sodium hydroxide. Then the temperature is raised to 140 ℃ and the mixture is refluxed and reacted for 4 hours, during which the water is gradually discharged through a water separator to obtain about 32g of water, and finally the metering water distribution reaches a theoretical value, which indicates that the reaction stage is finished. And continuously heating to 155 ℃ to evaporate most of the dimethylbenzene, washing the residual crude product with acetonitrile for 3 times, and spin-evaporating and drying to obtain 265g of bisphenol A disodium salt as a target product, wherein the yield is 97.4%, and the purity is 99% through GPC test.

Preparation of bisphenol A dipotassium salt

The preparation process is the same as that of bisphenol A disodium salt except that 80.5g of sodium hydroxide is changed into 138.3g of potassium carbonate, and the other is unchanged.

Preparation of bisphenol S dipotassium salt: the preparation process is identical to bisphenol A dipotassium salt, except that bisphenol S is used in the same molar amount instead of bisphenol A.

Preparation of biphenol dipotassium salt: the preparation process is the same as bisphenol A dipotassium salt, except that bisphenol A is replaced by the same molar amount of biphenol.

Preparation of the passivation component

The passivation component can be directly subjected to nucleophilic substitution reaction by adopting low molecular weight phenolic hydroxyl terminated polysulfone resin (commercially available) and monohalogenated monomers (such as chlorobutane, monochlorodiphenyl sulfone, monofluorodiphenyl sulfone and the like), or is customized by manufacturers.

In addition, the product can be obtained by self-made methods. For example, reference may be made to the preparation method of CN109354686a, and it should be noted that this reference should not be construed as limiting the scope of application of the present invention.

Passivation component 1: 570.6g of bisphenol A, 380.3g of potassium carbonate and 1000g of dimethylformamide are put into a 5L reaction kettle with nitrogen and a fractionating device, and stirred and mixed thoroughly, so that bisphenol A is completely dissolved, and the potassium carbonate is in a dispersed and suspended state. Then heating to 125 ℃ to carry out salt forming reaction, and continuously discharging distilled water-containing solvent in the middle until the water content of the fraction is lower than 1%. Then 683.7g of dichlorodiphenyl sulfone is added, the temperature is raised to 130 ℃, the aqueous solvent is continuously distilled until the water content of the fraction is lower than 0.5%, and finally the hydroxyl-terminated prepolymer solution is obtained. And (3) reducing the temperature to 110 ℃, adding 36.24g of monochlorodiphenyl sulfone, adding ethanol into the reaction solution after reacting for 2 hours to separate out solid matters, filtering, washing a filter cake with 70% DMF aqueous solution for 4 times, and filtering and drying to obtain a target product.

Passivation component 2: the amount of the above-mentioned dichlorodiphenyl sulfone to be charged was changed to 678.5g, and 36.24g of monochlorodiphenyl sulfone was changed to 40g of monofluorodiphenyl sulfone, with the other conditions unchanged.

Passivation component 3: the amount of the above-mentioned dichlorodiphenyl sulfone to be charged was changed to 691g, and the amount of the monochlorodiphenyl sulfone to be charged was changed to 28.4g, with other conditions unchanged.

Passivation component 4: the amount of the above-mentioned dichlorodiphenyl sulfone added was changed to 675g, and 36.24g of monochlorodiphenyl sulfone was changed to 16.6g of chlorobutane, with the other conditions unchanged.

Passivation component 5: the amount of the above-mentioned dichlorodiphenyl sulfone to be charged was changed to 681.2g, and the amount of the monochlorodiphenyl sulfone to be charged was changed to 38.7g, with other conditions unchanged.

The structural formula of the passivation components 1,2, 3 and 5 is as follows:

The structural formula of the passivation component 4 is as follows:

The passivation component obtained above was tested by GPC, the test method was as described above, and the results were as follows:

Example 1

The mixed solid of 6.09kg of fresh bisphenol A dipotassium salt and 5.8kg of dichlorodiphenyl sulfone is fully and evenly mixed in a high-speed mixer for standby. The twin-screw extruder (aspect ratio 90/1) was preheated according to the following protocol: the feeding section is set at 50 ℃, and the compression section is set at the temperature: 120 ℃, the polymerization section is set at the temperature: 220 ℃, plasticizing section temperature setting: 310 ℃, and simultaneously, nitrogen substitution is carried out on the inner cavity of the screw. After the temperature reached, 625.9g of passivation material (passivation component 5) was fed into the hopper and reaction extrusion was carried out while feeding. During extrusion, the nitrogen flow rate of the polymerization section was set to 0.2L/min, and the nitrogen flow rate of the plasticizing section was set to 0.4L/min, so that the melt was foamed. Finally, the foamed polymer crude resin is obtained. Crushing the crude resin by a high-speed dispersing machine, wherein the fineness of the crushed crude resin is 200-800 mu m, and obtaining resin powder. Repeatedly washing resin powder with 60% methanol water solution at reflux temperature for 3 times, and finally reflux washing with pure water once and oven drying to obtain resin product 8.5kg with 96.06%

Example 2

10657.5G of fresh bisphenol S dipotassium salt and 10255.7g of dichlorodiphenyl sulfone are fully and uniformly mixed in a high-speed mixer for standby. The twin-screw extruder (aspect ratio 75/1) was preheated according to the following protocol: the feeding section is set at 60 ℃, and the compression section is set at the temperature: setting the polymerization section at 140 ℃): 280 ℃, plasticizing section temperature setting: 320 ℃, and simultaneously carrying out nitrogen substitution on the inner cavity of the screw. After the temperature reached, 2324g of the mixed solids and passivation (passivation component 1 above) were added to the feed hopper and reaction extruded. During extrusion, the nitrogen flow rate of the polymerization section is set to be 0.3L/min, and the nitrogen flow rate of the plasticizing section is set to be 0.6L/min, so that the melt is foamed. Finally, the foamed polymer crude resin is obtained. Crushing the crude resin by using a high-speed dispersing machine to obtain resin powder. The resin powder was repeatedly washed with 55% ethyl acetate aqueous solution at reflux temperature for 5 times, and finally, was washed with pure water at reflux and dried to obtain 15130g of a resin product in 97.7% yield.

Example 3

A twin-screw extruder with double feed inlets was selected, and the aspect ratio of the extruder was 80/1. 4356.8g of fresh bisphenol A disodium salt solid powder and 2239g of passivating material (passivating component 4) are mixed and then put into one feeding port of an extruder, and 4599.16g of solid material of dichlorodiphenyl sulfone is put into the other feeding port of the extruder, and simultaneously fed, and the two materials are fully mixed in a feeding section and a compression section of the extruder. The feeding section of the extruder is set at 20 ℃, and the compression section is set at the temperature: setting the polymerization section at 100 ℃: setting the temperature of the plasticizing section at 250 ℃): during extrusion at 300 deg.c, the nitrogen flow rate in the polymerization section was set at 0.05L/min and the nitrogen flow rate in the plasticizing section was set at 0.2L/min to foam the melt. Finally, the foamed polymer crude resin is obtained. Crushing the crude resin by using a high-speed dispersing machine to obtain resin powder. Repeatedly washing the resin powder with 70% ethanol water solution for 4 times at reflux temperature, and finally carrying out reflux washing with pure water once and drying to obtain 6.6kg of resin product with the yield of 93.2%.

Example 4

6807.5G of fresh bisphenol A disodium salt and 7193.4g of dichlorodiphenyl sulfone are fully and uniformly mixed in a high-speed mixer, then the mixture is filled into a feed port of a double-screw extruder with the length-diameter ratio of 70/1, 141.4g of passivation material (the passivation component 3) is added into a second feed port, and meanwhile, the temperature of a feed section is set to be 40 ℃, the temperature of a compression section is set to be 135 ℃, the temperature of a polymerization section is set to be 200 ℃, and the temperature of a plasticizing section is set to be 320 ℃. The nitrogen inlet is respectively arranged at the feed inlet and the plasticizing section, the nitrogen flow rate of the feed section is regulated to be 0.1L/min, and the nitrogen flow rate of the plasticizing section is regulated to be 0.9L/min. And (3) carrying out reactive extrusion after the temperature of the screw is stabilized, carrying out underwater traction on the extruded polymer crude resin at the outlet of the screw, and granulating by using a granulator. The coarse resin particles were crushed in water with a crushing pump to obtain a resin powder. The resin powder was washed 5 times with 20% aqueous solution of methyl acetate, and finally washed once with pure water under reflux and dried to obtain 10.6kg of a resin product with a yield of 95.8%.

Example 5

9135G of biphenol dipotassium salt, 8658.1g of dichlorodiphenyl sulfone and 1547.2g of passivation material (passivation component 2) were thoroughly mixed by a horizontal mixer for later use. Preheating a double-screw extruder (length-diameter ratio is 85/1), setting the temperature of a feeding section at 60 ℃, the temperature of a compression section at 100 ℃, the temperature of a polymerization section at 260 ℃, the temperature of a plasticizing section at 315 ℃, adding a monomer mixed solid material after the temperature of a screw is stable, and performing reactive extrusion, wherein the nitrogen flow rate of the feeding section is regulated to be 0.5L/min and the nitrogen flow rate of the plasticizing section is regulated to be 1L/min in the extrusion process. The extruded polymer crude resin was drawn underwater at the screw outlet and pelletized with a pelletizer. Grinding and crushing the coarse resin particle grinder to obtain resin powder. The resin powder was washed with 50% aqueous methanol solution 4 times, and finally, was washed once with pure water under reflux and dried under vacuum with double cones to obtain 12.7kg of a resin product in a yield of 95.7%.

Comparative example

4567.5G of bisphenol A dipotassium salt and 4329g of dichlorodiphenyl sulfone are fully and uniformly mixed, the mixture is added into a feed hopper of a double screw extruder (length-diameter ratio is 85/1), the temperature of a feeding section of the extruder is set to 45 ℃, the temperature of a compression section is set to 110 ℃, the temperature of a polymerization section is set to 230 ℃, the temperature of a plasticizing section is set to 300 ℃, and meanwhile, nitrogen substitution is carried out on the inner cavity of a screw. During extrusion, a nitrogen flow of 0.6L/min is injected into an opening of a polymerization section, and reaction extrusion is performed after the temperature of a screw is stabilized.

Finally, a black viscous elastomer is obtained at the extruder head, and wiredrawing and molding cannot be performed. And continuing feeding, locking and stopping the extruder, and failing the experiment. After disassembling, the screw is filled with black solid hard blocks, and a small part of the solid hard blocks are carbonized.

This comparative example demonstrates that reactive extrusion of sulfone polymer resins cannot be successfully performed without the passivation component provided by the present invention.

In practical applications, nitrogen-containing impurities (mainly residual solvent molecules) in the resin can have a great influence on heat resistance and yellowness of the resin; in addition, the cyclic dimer in the resin also significantly reduces the melt extrusion properties and film formation permeability of the product.

The products obtained in the above examples were analyzed and compared with commercial products, and it was found that the molecular weight of the sulfone polymer resin prepared by the method of the present invention was close to that of the commercial products, and the molecular weight distribution was narrower. Meanwhile, through liquid phase tests, nitrogen-containing impurities are not detected in all the examples, and GPC test results prove that all the examples have lower cyclic dimer mass content, which proves that the invention has remarkable advantages.

	Mw/W	Molecular weight distribution	Total nitrogen content	Cyclic dimer content
					Example 1	12	1.61	Not detected	0.85％
Example 2	11.7	1.54	Not detected	0.92％
					Example 3	13.3	1.6	Not detected	0.7％
Example 4	12.8	1.57	Not detected	Not detected
					Example 5	12.5	1.53	Not detected	Not detected
Comparative example	> 100 (Cross-linking)	——	——	——
					S6010	12.2	1.65	62.1ppm	1.1％

Claims

1. A method for preparing a sulfone polymer resin, comprising the steps of:

(2) Injecting the mixed monomer and the passivation component into a double-screw extruder for extrusion to obtain the crude resin.

2. The method of manufacturing according to claim 1, characterized in that the method of manufacturing further comprises: (3) Crushing, washing and drying the crude resin to obtain the resin.

3. The process according to claim 1 or 2, wherein in step (1), the alkali metal salt of bisphenol monomer is a compound having the following structural formula:

Wherein M is an alkali metal, preferably K, na; r is an organic group comprising isopropyl, sulfonyl, -CH2-, carbonyl, oxygen atom or direct sigma bond, preferably isopropyl and sulfonyl;

preferably, in the step (1), the molar ratio of the alkali metal salt of the bisphenol monomer to the dichlorodiphenyl sulfone monomer is (0.980-0.999): 1, preferably (0.990-0.998): 1;

preferably, in step (1), the alkali metal salt of bisphenol monomer and dichlorodiphenyl sulfone monomer are mixed and then fed, or the two are fed separately and mixed in the feeding section of the extruder.

4. A method according to any one of claims 1 to 3, wherein in step (2), the passivating component is a compound having the structure:

Preferably, R1 and R2 have not more than 20 carbon atoms;

preferably, the passivating component comprises from 1 to 20%, preferably from 5 to 10% of the total mass of the charge.

5. The process according to any one of claims 1 to 4, wherein in step (2), the twin-screw extruder has an aspect ratio of (60 to 90): 1, preferably (70 to 80): 1;

Preferably, the twin screw extruder comprises a feeding section, a compression section, a polymerization section and a plasticizing section;

Preferably, in the step (2), the temperature of the feeding section is 20-60 ℃, and the temperature of the compression section is: the temperature of the polymerization section is 100-140 ℃, and the temperature of the polymerization section is as follows: 200-280 ℃, and the plasticizing section temperature is: 300-320 ℃.

6. The method according to any one of claims 1 to 5, wherein in the step (2), a reaction inert gas is introduced, and the reaction inert gas is one or more of nitrogen, carbon dioxide, helium, neon and argon;

preferably, the extrusion reaction is carried out in a reaction inert gas atmosphere;

preferably, the flow rate of the reaction inert gas in the polymerization section of the extruder is 0.05 to 0.5L/min, preferably 0.1 to 0.2L/min;

Preferably, the flow rate of the reaction inert gas in the plasticizing section of the extruder is 0.2 to 1.0L/min, preferably 0.5 to 0.8L/min.

7. The process according to any one of claims 2 to 6, wherein in step (3), the fineness of the crude resin after crushing is 200 to 800 μm, preferably 500 to 600 μm;

Preferably, in the step (3), the washing liquid is an aqueous solution prepared from one or more of methanol, ethanol, methyl acetate, ethyl acetate, tetrahydrofuran and acetonitrile, and the concentration is 20-70 wt%, preferably 50-60 wt%;

preferably, in step (3), water is used for the last wash.