Sulfone resin micropowder, and preparation method and application thereof

Abstract

This invention discloses a sulfone resin micropowder, its preparation method, and its application, belonging to the field of polymer materials technology. In the preparation method of the sulfone resin micropowder provided by this invention, a good solvent is added to the reaction system after the polymerization reaction, which can effectively improve the solubility of the polymerized sulfone resin. Simultaneously, adding a dispersant after adding the good solvent can more effectively improve the dispersion effect of the polymerized sulfone resin. Therefore, when supercritical carbon dioxide within a certain pressure range is subsequently introduced into water at a specific flow rate for precipitation, the polymerized sulfone resin can be dispersed into finer and more uniform droplets, shortening the solidification time of the sulfone resin in water, reducing the introduction of impurities, and improving the purity of the sulfone resin.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, and particularly relates to a sulfone resin micro powder, its preparation method and application. Background Technology

[0002] Currently, the method for preparing sulfone resin powder coatings involves secondary processing of the synthesized primary resin powder to produce a fine-particle-size micro-powder slurry. The processing method involves mixing the resin powder, solvent, and water in a specific ratio to form a slurry, which is then subjected to prolonged wet grinding in a ball mill. This method suffers from the problems of long grinding times and a wide, uneven particle size distribution in the resulting powder. Furthermore, the molecular structure of the sulfone resin is damaged by mechanical forces during ball milling, making it prone to yellowing during application.

[0003] To address the aforementioned problems, numerous solutions have been proposed in the existing technology. Chinese patents with application numbers CN201410136633.5 and CN200510016654.4 disclose a method for preparing redispersible polyarylether sulfone micropowders: first, polyarylether sulfone resin is dissolved in a mixed solution of an organic solvent and a co-solvent to form a solution; then, the solvent is slowly added to an aqueous surfactant solution and dispersed at high speed to obtain an emulsion; the emulsion is diluted with deionized water and added to an extractant; then, the mixture is centrifuged or filtered to obtain polyethersulfone micropowders; or the emulsion is evaporated to remove the organic solvent, and then dried to prepare the micropowder. The disadvantages of the preparation methods disclosed in these two patents are: the surfactant used leaves residues in the resin, which decompose at high temperatures, causing significant yellowing of the product; simultaneously, surfactant residues remain in the wastewater during purification, making recovery difficult and potentially leading to environmental pollution. Chinese patent application CN201910054395.6 discloses a method for preparing micro-powder by constructing a slightly turbid dispersion system from polyethersulfone, a mixed solvent, and water, followed by coagulation separation and drying. The main drawback of this method is the use of deionized water for washing during purification, requiring 20-40 times the weight of the resin, resulting in high water consumption and wastewater treatment costs. Chinese patent application CN201711188865.5 discloses an industrial synthesis method for coating-grade ultrafine polyarylene ethersulfone resin. During the polymerization reaction, aromatic diphenols are added to the system, followed by dilution of the polymer viscous liquid with a mixture of deionized water and sulfolane. The mixture is then pulverized, purified, and dried to obtain pure coating-grade polyarylene ethersulfone resin ultrafine powder. The disadvantage of this method is that the diphenols added during the polymerization reaction react with dichlorophenoxyacetic acid in the raw material, generating long-chain byproducts that affect product purity. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a sulfone resin micro powder with low oligomer content, small D50 particle size and uniform particle size distribution, as well as its preparation method and application.

[0005] To achieve the above objectives, in a first aspect, the present invention provides a method for preparing sulfone resin micropowder, the method comprising the following steps:

[0006] (1) Sulfone resin monomers, azeotropic agents, and salt-forming agents are added to the reaction solvent in an inert gas environment to carry out salt-forming and polymerization reactions;

[0007] (2) After the polymerization reaction is completed, the temperature is lowered, and a good solvent and a dispersant are added to the cooled reaction system in sequence and stirred evenly to obtain a mixed solution;

[0008] (3) After introducing supercritical carbon dioxide with a pressure ≥8MPa into the mixed solution and maintaining it, after the maintenance is completed, the mixed solution is added to water at a flow rate of 10-300L / min, then boiled, solid-liquid separated, the filter residue is collected and dried to obtain sulfone resin.

[0009] The good solvent includes at least one of N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, and dimethyl sulfoxide;

[0010] The dispersant includes at least one of chloroform, dichloroethane, ethanol, 1,3-propanediol, ethyl acetate, and butyl acetate.

[0011] In the preparation method of sulfone resin micro powder provided by this invention, the temperature is lowered after the polymerization reaction is completed, and a good solvent is added to the cooled reaction system, which can effectively improve the solubility of the polymerized sulfone resin. At the same time, the addition of a dispersant after the addition of a good solvent can more effectively improve the dispersion effect of the polymerized sulfone resin. As a result, when supercritical carbon dioxide within a certain pressure range is introduced into water at a specific flow rate for precipitation, the polymerized sulfone resin can be dispersed into finer and more uniform droplets, shortening the solidification time of the sulfone resin in water, reducing the introduction of impurities, and lowering the oligomer content in the resin.

[0012] For example, the pressure of the supercritical carbon dioxide can be any point value or any two points within a range of ≥8 MPa, such as 10-30 MPa, 15-20 MPa, or 8 MPa, 10 MPa, 12 MPa, 14 MPa, 16 MPa, 18 MPa, 20 MPa, 22 MPa, 24 MPa, 26 MPa, 28 MPa, 30 MPa, etc.

[0013] Preferably, the pressure of the supercritical carbon dioxide is 10-30 MPa.

[0014] More preferably, the pressure of the supercritical carbon dioxide is 15-20 MPa.

[0015] This invention reveals that supercritical carbon dioxide and sulfone resins can undergo effective mutual swelling and diffusion, which, when subsequently added to water at a certain rate, is more conducive to the dispersion of sulfone resins into products with smaller D50 particle sizes and more uniform particle size distribution. In particular, when the supercritical carbon dioxide pressure is further selected at 15-20 MPa, the overall performance of the resulting sulfone resin is even better. If the supercritical carbon dioxide pressure is too low, the swelling effect will be insignificant, thus hindering subsequent dispersion; if the supercritical carbon dioxide pressure is too high, it will increase the manufacturing requirements of the equipment, and also increase the requirements for the stability of the pressure release process when added to water at a certain flow rate.

[0016] For example, the flow rate can be any point value or any two-point range value between 10-300 L / min, such as 12-290 L / min, 150-200 L / min, or 10 L / min, 10 L / min, 30 L / min, 50 L / min, 70 L / min, 90 L / min, 100 L / min, 120 L / min, 140 L / min, 160 L / min, 180 L / min, 200 L / min, 220 L / min, 240 L / min, 260 L / min, 280 L / min, 300 L / min, etc.

[0017] Preferably, supercritical carbon dioxide at a pressure of 10-30 MPa is introduced into the mixed solution and then added to water at a flow rate of 150-200 L / min.

[0018] This invention has discovered that when supercritical carbon dioxide is introduced into a mixed solution at a certain pressure, a swelling effect occurs between the supercritical carbon dioxide and sulfone resins. Subsequently, the system is added to water at a flow rate of 10-300 L / min for precipitation. This avoids the problems of poor dispersion of sulfone resins due to excessively low flow rates, which leads to increased oligomer content and D50 particle size. It also avoids the problem of uneven particle size distribution caused by decreased flow control stability due to excessively high flow rates. In other words, adding water for precipitation within the flow rate range given in this invention effectively disperses sulfone resins, causing them to precipitate in water as micro-powders with small D50 particle size and uniform particle size distribution, while maintaining low oligomer content and high purity. In particular, when the flow rate is further selected to be 150-200 L / min, the overall performance of the obtained product is even better.

[0019] In a preferred embodiment of the preparation method of the present invention, the good solvent includes N-methylpyrrolidone and N,N-dimethylformamide, and the mass ratio of N-methylpyrrolidone to N,N-dimethylformamide is 1:(5-15).

[0020] For example, the mass ratio of N-methylpyrrolidone to N,N-dimethylformamide can be any point value or any two points between 1:(5-15), such as 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, etc.

[0021] Preferably, the good solvent comprises N-methylpyrrolidone and N,N-dimethylformamide, wherein the mass ratio of N-methylpyrrolidone to N,N-dimethylformamide is 1:(8-10).

[0022] This invention has found that the addition of specific types of good solvents can effectively improve the solubility of sulfone resins, thereby facilitating subsequent swelling with supercritical carbon dioxide and dispersion in the precipitant water. This helps reduce the D50 particle size of the resulting sulfone resins, improves particle size distribution uniformity, reduces oligomer content, and increases product purity. In particular, when the good solvent is further selected as a mixture of N-methylpyrrolidone and N,N-dimethylformamide in a mass ratio of 1:(8-10), the overall effect of the obtained sulfone resins is even better.

[0023] In a preferred embodiment of the preparation method of the present invention, the dispersant comprises dichloroethane and butyl acetate, wherein the mass ratio of dichloroethane to butyl acetate is 1:(1-8).

[0024] For example, the mass ratio of dichloroethane to butyl acetate can be any point value or any two points between 1:(1-8), such as 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, etc.

[0025] Preferably, the dispersant comprises dichloroethane and butyl acetate, wherein the mass ratio of dichloroethane to butyl acetate is 1:(3-5).

[0026] This invention has found that the type of dispersant affects the dispersion effect of the sulfone resin generated after the polymerization reaction in the solvent. After adding a suitable type of good solvent, the dispersant selected in this invention can effectively disperse the sulfone resin, thereby helping to improve the micronization and purity of the sulfone resin. In particular, when the dispersant is further selected as dichloroethane and butyl acetate in a mass ratio of 1:(3-5), the overall effect of the product is even better.

[0027] In a preferred embodiment of the preparation method described in this invention, the mass percentage of the good solvent is 5-60% based on the mass of the reaction solvent.

[0028] For example, the mass percentage of the good solvent, based on the mass of the reaction solvent, can be any point value or any two-point range between 5% and 60%, such as 6%-58%, or it can be 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, etc.

[0029] Preferably, the mass percentage of the good solvent is 30-40% based on the mass of the reaction solvent. For example, it can be 30%, 32%, 34%, 36%, 38%, 40%, etc.

[0030] The present invention has found that when the mass percentage of a good solvent is 5-60%, especially 30-40%, it can not only effectively dissolve sulfone resins but also have a good interaction with the dispersant. At the same time, it can avoid the impact of adding too much good solvent on purity, resulting in a product with better overall performance.

[0031] In a preferred embodiment of the preparation method of the present invention, the dispersant has a mass percentage of 0.1-30% based on the mass of the reaction solvent.

[0032] For example, the mass percentage of the dispersant, based on the mass of the reaction solvent, can be any point value or any two-point range between 0.1% and 30%, such as 0.5%-28%, or 0.1%, 0.5%, 1%, 3%, 5%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, etc.

[0033] Preferably, the dispersant comprises 10-15% by mass of the reaction solvent.

[0034] The present invention has found that when the mass percentage of the dispersant is selected as 0.1-30%, especially 10-15%, it can not only improve the dispersion effect of sulfone resin after dissolution in a good solvent, but also effectively control the oligomer content in the subsequently obtained sulfone resin micro powder, thereby improving the overall performance of the product.

[0035] In a preferred embodiment of the preparation method of the present invention, in step (2), the temperature of the reaction system after cooling is 40-80℃.

[0036] This invention has found that further cooling the reaction system to 40-80°C before adding a good solvent and dispersant can help the good solvent and dispersant exert their respective effects more effectively, thereby improving the overall performance of the product.

[0037] In a preferred embodiment of the preparation method described in this invention, the temperature of the supercritical carbon dioxide is 40-80°C.

[0038] For example, the temperature of the supercritical carbon dioxide can be any point value or any two-point range value between 40-80℃, such as 40℃, 50℃, 60℃, 70℃, 80℃, etc.

[0039] In a preferred embodiment of the preparation method of the present invention, the holding time in step (3) is 0.5-6h.

[0040] For example, the holding time can be any point value or any two-point range value between 0.5 and 6 hours, such as 0.5 hours, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, etc.

[0041] Preferably, the holding time is 2-3 hours.

[0042] This invention has found that maintaining the carbon dioxide flow for an appropriate time can reduce the introduction of impurities while fully swelling the sulfone resin, thereby improving the overall performance of the product.

[0043] In a preferred embodiment of the preparation method of the present invention, in step (2), the stirring time after adding the good solvent and dispersant in sequence is 0.5-2h, the stirring speed is 200-400r / min, and the temperature of the material during stirring is 180-200℃.

[0044] In a preferred embodiment of the preparation method of the present invention, in step (3), the mass percentage of water is 400-600% based on the mass of the reaction solvent.

[0045] This invention has found that a suitable percentage of water by mass can effectively precipitate sulfone resins, helping to achieve the excellent overall performance of sulfone resins.

[0046] In a preferred embodiment of the preparation method of the present invention, the boiling time in step (3) is 0.5-2h.

[0047] As a preferred embodiment of the preparation method of the present invention, in step (3), the solid-liquid separation further includes a washing process of the filter residue, the washing is performed 8-10 times, and the washing liquid does not become turbid when tested with silver nitrate.

[0048] The method for preparing sulfone resin micropowder provided by this invention is suitable for the preparation of all sulfone resins, such as bisphenol A polysulfone, polyethersulfone, polyphenylsulfone, etc. In the salt-forming and polymerization stages of the preparation process, the sulfone resin reactants, azeotropic agents, salt-forming agents, and reaction solvents used in this invention are all substances conventionally used in the art.

[0049] For example, when the sulfone resin is bisphenol A type polysulfone, the reactant monomers are 4,4'-dichlorodiphenyl sulfone and 2,2-di(4-hydroxyphenyl)propane, the azeotropic agent is xylene, the salt-forming agent is potassium hydroxide, and the reaction solvent is sulfolane, N,N-dimethylacetamide, and / or dimethyl sulfoxide; when the sulfone resin is polyethersulfone, the reactant monomers are 4,4'-dichlorodiphenyl sulfone and 4,4'-dihydroxydiphenyl sulfone, the azeotropic agent is xylene, the salt-forming agent is sodium carbonate, and the reaction solvent is sulfolane, N,N-dimethylformamide, and / or diphenyl sulfone; when the sulfone resin is polyphenylsulfone, the reactant monomers are 4,4'-dichlorodiphenyl sulfone and 4,4'-biphenylhydrazine, the azeotropic agent is xylene, the salt-forming agent is sodium carbonate, and the reaction solvent is sulfolane and / or N,N-dimethylformamide.

[0050] Preferably, during the salt formation reaction stage, the temperature of the salt formation reaction is 180-220℃, and the time of the salt formation reaction is 4-6 hours.

[0051] Preferably, during the polymerization reaction stage, the polymerization temperature is 230-240℃ and the polymerization time is 2-3 hours.

[0052] Preferably, the inert gas environment includes a nitrogen environment and a rare gas environment.

[0053] In a second aspect, the present invention provides a sulfone resin micro powder, which is prepared by the preparation method described in the present invention.

[0054] As a preferred embodiment of the sulfone resin micro powder of the present invention, the sulfone resin micro powder has a D50 particle size ≤15μm, a particle size distribution uniformity P of 1.03-1.54, and an oligomer content ≤1.47wt%.

[0055] In a third aspect, the present invention provides a coating comprising the sulfone resin micron powder described herein.

[0056] For example, the coating may be a powder coating.

[0057] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0058] The present invention provides a method for preparing sulfone resin micropowder. After the polymerization reaction is completed, the temperature is lowered, and a good solvent is added to the cooled reaction system. This effectively improves the solubility of the polymerized sulfone resin. Simultaneously, adding a dispersant after the good solvent further enhances the dispersion of the polymerized sulfone resin. This allows the polymerized sulfone resin to be dispersed into finer, more uniform droplets when supercritical carbon dioxide is introduced within a certain pressure range and added to water at a specific flow rate for precipitation. This shortens the solidification time of the sulfone resin in water, reduces the introduction of impurities, and improves the purity of the sulfone resin. Furthermore, the method for preparing sulfone resin micropowder provided by the present invention is simple to operate, does not generate other byproducts, and requires less washing water, which is beneficial for practical production applications. Detailed Implementation

[0059] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0060] Unless otherwise specified, the reagents, methods and equipment used in this invention are all conventional reagents, methods and equipment in the field.

[0061] Example 1

[0062] This invention provides a sulfone-based resin micropowder (polyether sulfone PES), the preparation method of which includes the following steps:

[0063] (1) Quantitatively add 1285g of reaction solvent (sulfolane), sulfone resin monomers (293g of 4,4'-dichlorodiphenyl sulfone and 257g of 4,4'-dihydroxydiphenyl sulfone), 111g of salt-forming agent (sodium carbonate), and 105g of azeotropic agent (xylene) to a 5L reactor. Evacuate the reactor and purge with nitrogen three times. Under nitrogen protection, raise the temperature to 205℃ for a salt-forming reaction for 5 hours. During the salt-forming reaction, the azeotropic agent continuously removes water produced by the reaction through azeotropic action until no more water is discharged, at which point the salt-forming reaction ends. Subsequently, raise the temperature to 235℃ for a polymerization reaction for 3 hours.

[0064] (2) After the polymerization reaction is completed, the temperature is lowered to 60°C. Then, a good solvent (30% by mass of the good solvent, which is N-methylpyrrolidone) is added to the cooled reaction system and stirred at 300 r / min for 1 h while maintaining the material temperature at 60°C. Next, a dispersant (10% by mass of the dispersant, which is a mixture of 1,3-propanediol and ethyl acetate in a mass ratio of 1:4) is added and stirred at 300 r / min for 1 h while maintaining the material temperature at 60°C to obtain a mixed solution.

[0065] (3) Supercritical carbon dioxide (pressure 18 MPa, temperature 60 °C) was introduced into the mixed solution. After the introduction was completed, it was kept for 1 h. After 1 h, the mixed solution was added to a dispersion vessel containing water (400% by mass of the reaction solvent) at a flow rate of 200 L / min to precipitate. Then it was boiled for 1 h. Then the solid and liquid were separated, the filter residue was collected and washed 9 times. The washing liquid was washed until it did not become turbid when tested with silver nitrate. Then the filter residue was dried under vacuum to obtain sulfone resin (polyether sulfone PES) micro powder.

[0066] Examples 2-23 and Comparative Examples 1-5

[0067] The embodiments and comparative examples of this invention investigate the effects of the type and amount of good solvent, the type and amount of dispersant, the parameters of supercritical carbon dioxide, the mass percentage of water as precipitant, and the flow rate. Except for the parameters in Table 1, all other parameters are consistent with those of Example 1. The mass percentages of good solvent, dispersant, and water as precipitant are all based on the mass of the reaction solvent. The parameters of Example 1 are listed in Table 1.

[0068] In Comparative Example 1 and Comparative Example 2, " / " indicates that a certain substance is not added. That is, the difference between Comparative Example 1 and Example 1 is that no good solvent is added, and the difference between Comparative Example 2 and Example 1 is that no dispersant is added.

[0069] Table 1

[0070]

[0071]

[0072]

[0073] Example 24

[0074] This invention provides a sulfone resin micro powder (polyphenylsulfone PPSU), the preparation method of which includes the following steps:

[0075] (1) Quantitatively add 1285g of reaction solvent (sulfolane), 316g of 4,4'-dichlorodiphenyl sulfone, 197g of 4,4'-biphenylhydrazine, 111g of salt-forming agent (sodium carbonate), and 124g of azeotropic agent (toluene) to a 5L reactor. Evacuate the reactor and purge with nitrogen three times. Under nitrogen protection, raise the temperature to 200℃ for a salt-forming reaction for 5 hours. During the salt-forming reaction, the azeotropic agent continuously removes water produced by the reaction through azeotropic action until no more water is discharged, at which point the salt-forming reaction ends. Subsequently, raise the temperature to 235℃ for a polymerization reaction for 3 hours.

[0076] (2) After the polymerization reaction is completed, the temperature is lowered to 50°C. Then, a good solvent (30% by mass of the good solvent, which is N-methylpyrrolidone) is added to the cooled reaction system and stirred at 300 r / min for 1 h while maintaining the material temperature at 50°C. Next, a dispersant (10% by mass of the dispersant, which is a mixture of 1,3-propanediol and ethyl acetate in a mass ratio of 1:4) is added and stirred at 300 r / min for 1 h while maintaining the material temperature at 50°C to obtain a mixed solution.

[0077] (3) After maintaining the mixed solution with supercritical carbon dioxide (pressure 18MPa, temperature 60℃) for 1h, it is added to a dispersion vessel containing water (water mass percentage of 510% based on the mass of the reaction solvent) at a flow rate of 200L / min to precipitate. Then, it is boiled for 1h, followed by solid-liquid separation. The filter residue is collected and washed 9 times until the washing liquid does not become turbid when tested with silver nitrate. Then, the filter residue is vacuum dried to obtain sulfone resin (polyphenylsulfone PPSU) micro powder.

[0078] Example of effect

[0079] The effects of this invention are investigated by examining the D50 particle size, particle size distribution uniformity, and purity of the sulfone resin micropowders prepared in Examples 1-24 and Comparative Examples 1-5.

[0080] 1. The test method for D50 particle size and particle size distribution uniformity is as follows: The sample is placed in a dispersion medium (ethanol) and the particles are dispersed in an ultrasonic environment to form a uniform suspension. Then, the suspension is placed in the sample cell of a Mastersizer 3000+Lab laser particle size analyzer for testing. The D50 particle size is recorded and the particle size distribution uniformity is calculated. The particle size distribution uniformity P = (D90 - D10) / D50. The closer the P value is to 1, the better the particle size distribution uniformity, i.e., the more uniform the distribution.

[0081] 2. The test method for oligomer content is as follows: The oligomer content (S) in the resin is tested by gel permeation chromatography (GPC), with polystyrene or polymethyl methacrylate as the standard and THF or DMF as the mobile phase.

[0082] The results are shown in Table 2;

[0083] Table 2

[0084]

[0085]

[0086] As can be seen from Table 2, when the preparation method provided by the present invention is used, the obtained sulfone resin micro powder has a small D50 particle size and a relatively uniform particle size distribution, and the obtained sulfone resin micro powder has a low oligomer content; specifically, the obtained sulfone resin micro powder has a D50 particle size between 4.43 and 14.77 μm, a particle size distribution uniformity between 1.03 and 1.54, and an oligomer content of less than 1.47 wt%.

[0087] As can be seen from Examples 1-8 and Comparative Example 1, the type of good solvent and the amount added relative to the reaction solvent will affect the overall performance of sulfone resin micro powder to a certain extent. When no good solvent is added after the polymerization reaction in Comparative Example 1, the particle size of the obtained sulfone resin D50 increases significantly, the uniformity of particle size distribution deteriorates significantly, and the oligomer content also shows a certain upward trend.

[0088] As can be seen from Examples 1, 9-15 and Comparative Example 2, the type of dispersant and the amount added relative to the reaction solvent will affect the overall performance of sulfone resin micro powder to a certain extent. When no dispersant is added in Comparative Example 2, the particle size of the obtained sulfone resin D50 increases significantly and the uniformity of particle size distribution also deteriorates significantly. At the same time, the oligomer content also shows a certain upward trend.

[0089] As can be seen from Examples 1, 16-17 and Comparative Example 3, the pressure of supercritical carbon dioxide affects the overall performance of sulfone resins. When the pressure of supercritical carbon dioxide in Comparative Example 3 is too low, the particle size of the obtained sulfone resin D50 increases significantly, the uniformity of particle size distribution deteriorates significantly, and the oligomer content also shows a certain upward trend.

[0090] As can be seen from Examples 1, 21-23 and Comparative Examples 4-5, the flow rate of the mixed solution into the precipitant water also affects the performance of sulfone resins. When the flow rate is too low in Comparative Example 4 or too high in Comparative Example 5, the particle size of the obtained sulfone resin D50 increases sharply and the uniformity of particle size distribution decreases significantly. At the same time, the oligomer content also shows a significant upward trend.

[0091] Finally, it should be noted that the above embodiments are used to illustrate the technical solutions of the present invention and not to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for producing a sulfone resin fine powder, characterized by comprising the steps of: The preparation method includes the following steps: ​ (1) Sulfone resin monomers, azeotropic agents, and salt-forming agents are added to the reaction solvent in an inert gas environment to carry out salt-forming and polymerization reactions; (2) After the polymerization reaction is completed, the temperature is lowered, and a good solvent and a dispersant are added to the cooled reaction system in sequence and stirred evenly to obtain a mixed solution; (3) After introducing supercritical carbon dioxide with a pressure ≥8MPa into the mixed solution and maintaining it, after the maintenance is completed, add the mixed solution into water at a flow rate of 12-290L / min, then boil, separate the solid and liquid, collect the filter residue and dry it to obtain sulfone resin. The good solvent includes at least one of N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, and dimethyl sulfoxide; The dispersant includes at least one of chloroform, dichloroethane, ethanol, 1,3-propanediol, ethyl acetate, and butyl acetate.

2. The production method according to claim 1, characterized by, The good solvent includes N-methylpyrrolidone and N,N-dimethylformamide, with a mass ratio of N-methylpyrrolidone to N,N-dimethylformamide of 1:(5-15). And / or, the dispersant comprises dichloroethane and butyl acetate, wherein the mass ratio of dichloroethane to butyl acetate is 1:(1-8).

3. The preparation method according to claim 1, characterized in that, The good solvent comprises 5-60% by mass of the reaction solvent; And / or, the dispersant is 0.1-30% by mass, based on the mass of the reaction solvent.

4. The method of claim 1, wherein, In step (2), the temperature of the reaction system after cooling is 40-80℃.

5. The preparation method according to claim 1, characterized in that, The temperature of the supercritical carbon dioxide is 40-80℃.

6. The preparation method according to claim 1, characterized in that, In step (3), the holding time is 0.5-6 hours.

7. The preparation method according to claim 1, characterized in that, In step (3), the water mass percentage is 400-600% based on the mass of the reaction solvent.

8. A sulfone-based resin micro powder, characterized in that, The sulfone resin micro powder is prepared by the preparation method described in any one of claims 1-7.

9. The sulfone resin micro powder according to claim 8, characterized in that, The sulfone resin micro powder has a D50 particle size ≤15μm, a particle size distribution uniformity P of 1.03-1.54, and an oligomer content ≤1.47wt%.

10. A coating, characterized in that, It includes the sulfone resin micro powder according to any one of claims 8-9.

Images