Method for producing aromatic polysulfone particles

Abstract

To provide a method for producing aromatic polysulfone particles that has high filterability and can prevent scaling of the resin particle deposition tank wall. [Solution] A method for producing aromatic polysulfone particles using an aromatic polysulfone solution containing an aromatic polysulfone and a non-protic solvent, comprising step (A) of discharging the aromatic polysulfone solution from a nozzle 10 into a solvent 50 containing a protic solvent, wherein in step (A), the discharge port 12 of the nozzle 10 is immersed in the solvent 50 containing a protic solvent.

Description

Technical Field

[0001] The present disclosure relates to a method for producing aromatic polysulfone particles.

Background Art

[0002] Aromatic polysulfone is used in various applications such as the electric and electronic fields, mechanical fields, automotive fields, aircraft fields, and medical and food industrial fields.

[0003] As a method for isolating resin particles of an aromatic polymer from a polymerization solution, a precipitation method using a poor solvent is known. For example, Patent Document 1 discloses a method in which a polar solvent solution of a polymer having a benzene ring is sprayed from above through a spray nozzle toward the liquid surface of a poor solvent of the polymer in a cylindrical container to obtain resin particles precipitated in the poor solvent of the polymer.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the resin particles obtained from the resin particle precipitation method disclosed in Patent Document 1 have low filterability. The low filterability has a problem that solid-liquid separation takes a long time and leads to a decrease in productivity. In addition, adhesion of the resin solution to the wall surface of the cylindrical container and deposition of the resin (hereinafter also referred to as scaling) occur, which also causes problems such as fouling of the equipment and a decrease in the yield.

[0006] The present disclosure has been made in view of such circumstances, and an object thereof is to provide a method for producing aromatic polysulfone particles that has high filterability and can prevent scaling on the wall surface of the resin particle precipitation tank.

Means for Solving the Problems

[0007] To address the above issues, this disclosure includes the following configuration.

[0008] [1] A method for producing aromatic polysulfone particles using an aromatic polysulfone solution comprising an aromatic polysulfone and a non-protic solvent, comprising step (A) of discharging the aromatic polysulfone solution from a nozzle into a solvent containing the protic solvent, wherein in step (A), the discharge port of the nozzle is immersed in the solvent containing the protic solvent.

[0009] [2] A method for producing aromatic polysulfone particles according to [1], wherein the gas and the aromatic polysulfone solution are mixed inside the nozzle.

[0010] [3] A method for producing aromatic polysulfone particles according to [1] or [2], wherein the nozzle is a multifluid nozzle, and the method includes a step (B) of dropletizing the aromatic polysulfone solution with the multifluid nozzle.

[0011] [4] The method for producing aromatic polysulfone particles according to [3], wherein the multifluid nozzle is a two-fluid nozzle.

[0012] [5] A method for producing aromatic polysulfone particles according to any one of [1] to [4], wherein the discharge diameter of the nozzle is greater than 0.5 mm and 15 mm or less.

[0013] [6] A method for producing aromatic polysulfone particles according to any one of [1] to [5], wherein the concentration of aromatic polysulfone in the aromatic polysulfone solution is 15 to 50% by mass.

[0014] [7] A method for producing aromatic polysulfone particles according to any one of [1] to [6], wherein the aprotic solvent is at least one solvent selected from the group consisting of dimethyl sulfoxide, N,N-dimethylformamide, sulfolane, N-ethyl-2-pyrrolidone, N-methyl-2-pyrrolidone, N,N-dimethylacetamide, and 1,3-dimethyl-2-imidazolidinone.

[0015] [8] A method for producing aromatic polysulfone particles according to any one of [1] to [7], wherein the protic solvent is at least one solvent selected from the group consisting of water, methanol, ethanol, 1-propanol, 2-propanol, n-butanol, butanol isomers, n-pentanol, pentanol isomers, n-hexanol, and hexanol isomers. [Effects of the Invention]

[0016] According to this disclosure, it is possible to provide a method for producing aromatic polysulfone particles that has high filterability and can prevent scaling of the resin particle deposition tank wall. [Brief explanation of the drawing]

[0017] [Figure 1] This is a schematic diagram of one embodiment of an apparatus for producing aromatic polysulfone particles. [Modes for carrying out the invention]

[0018] Hereinafter, one embodiment of this disclosure will be described with reference to the drawings. The dimensional ratios in Figure 1 do not necessarily correspond to the actual dimensional ratios.

[0019] Embodiments of the present disclosure are methods for producing aromatic polysulfone particles from an aromatic polysulfone solution comprising an aromatic polysulfone and an aprotic solvent, The process includes step (A) of discharging the aromatic polysulfone solution from a nozzle into a solvent containing a protic solvent.

[0020] In this disclosure, "aprotic solvent" means a solvent that does not have a functional group capable of removing protons. In this disclosure, "protic solvent" means a solvent that contains detachable protons.

[0021] <Equipment for manufacturing aromatic polysulfone particles> Figure 1 is a schematic diagram of one embodiment of an apparatus for producing aromatic polysulfone particles.

[0022] The apparatus for producing aromatic polysulfone particles comprises a resin particle deposition tank 1, a nozzle 10, and a stirrer 20. A filter cloth 40 is installed near the bottom of the resin particle deposition tank 1, and the bottom of the resin particle deposition tank 1 is connected to a drainage passage 30 which is opened and closed by a drainage valve 31.

[0023] The resin particle precipitation tank 1 is a tank into which a solvent 50 containing a protic solvent is introduced. The precipitation of aromatic polysulfone particles, described later, occurs in the solvent 50 containing the protic solvent introduced into the resin particle precipitation tank 1. The gas phase 60 of the resin particle deposition tank 1, in which the solvent 50 containing a protic solvent has not been introduced, may be filled with air or with an inert gas. Examples of such inert gases include nitrogen, argon, helium, and carbon dioxide.

[0024] Nozzle 10 is a two-fluid nozzle. The supply port 11a of nozzle 10 is for supplying aromatic polysulfone solution. The supply port 11b is for supplying gas. The gas may be air or an inert gas. Examples of inert gases include nitrogen, argon, and helium. The gas is preferably an inert gas, and nitrogen is more preferably one.

[0025] In step (A) above, the discharge mode of the nozzle 10 may be any of the following: a fan-shaped nozzle in which the discharged fluid spreads in a fan shape, a cone-shaped nozzle in which the discharged fluid spreads in a cone shape, a pyramidal nozzle in which the discharged fluid spreads in a square pyramidal shape, a straight-traveling nozzle in which the discharged fluid travels in a straight line, a mist-generating nozzle in which the discharged fluid spreads in a mist-like manner, or a porous slit nozzle in which the discharged fluid forms a film.

[0026] The discharge port 12 of the nozzle 10 is immersed in a solvent 50 containing a protic solvent. That is, the discharge port 12 of the nozzle 10 is located in the solvent 50 containing a protic solvent that has been introduced into the resin particle deposition tank 1. The discharge port 12 is located at a depth d relative to the solvent level 51 containing the protic solvent.

[0027] The material, size, and shape of the resin particle deposition tank 1, agitator 20, drainage channel 30, drainage valve 31, and filter cloth 40 are not particularly limited, and conventionally known materials can be used. Examples of materials for the filter cloth 40 include polyethylene, polyester, polypropylene, aromatic polyamide, polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene chloride, cellulose acetate, cellulose mixed ester, and nylon. The air permeability of filter cloth 40 is, for example, 10 to 20,000 cm². 3 / cm 2 min, 100-15000cm 3 / cm 2 • min, 1000~10000cm 3 / cm 2 It is acceptable to be a rookie.

[0028] <Method for producing aromatic polysulfone particles> One embodiment of a method for producing aromatic polysulfone particles using the aromatic polysulfone particle production apparatus shown in Figure 1 is described below.

[0029] The aromatic polysulfone described later is dissolved in the aprotic solvent to obtain an aromatic polysulfone solution.

[0030] The aprotic solvent may consist solely of polar solvents. Examples of the aprotic solvent include ethers; esters; ketones; halogenated hydrocarbons; anisoles; sulfoxides such as dimethyl sulfoxide; amides such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, or N-ethyl-2-pyrrolidone; sulfones such as sulfolane, dimethyl sulfone, diethyl sulfone, diisopropyl sulfone, and diphenyl sulfone; and 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, etc.

[0031] The aprotic solvent is preferably at least one solvent selected from the group consisting of dimethyl sulfoxide, N,N-dimethylformamide, sulfolane, N-ethyl-2-pyrrolidone, N-methyl-2-pyrrolidone, N,N-dimethylacetamide, and 1,3-dimethyl-2-imidazolidinone.

[0032] The content of the aprotic solvent in the aromatic polysulfone solution may be 45 to 85% by mass, 45 to 80% by mass, 50 to 75% by mass, or 50 to 70% by mass, based on the total mass of the aromatic polysulfone solution.

[0033] The concentration of aromatic polysulfone in the aromatic polysulfone solution may be 15 to 55% by mass, 20 to 55% by mass, 25 to 50% by mass, or 30 to 50% by mass. If the concentration of the aromatic polysulfone solution is above the lower limit, the filterability can be improved. If the concentration of the aromatic polysulfone solution is below the upper limit, the preparation of the aromatic polysulfone solution is easy, and poor dispensing of the aromatic polysulfone solution in step (A) can be prevented, and the amount of residual aprotic solvent in the resulting aromatic polysulfone particles can be reduced.

[0034] The temperature of the aromatic polysulfone solution may be arbitrarily changed within a range below the boiling point of the aprotic solvent in order to adjust the liquid delivery rate to the nozzle described later. For example, if N-methyl-2-pyrrolidone is selected as the aprotic solvent, the temperature may be 20 to 190°C or 20 to 100°C.

[0035] A solvent 50 containing a protic solvent is introduced into the resin particle deposition tank 1.

[0036] Examples of the protic solvent include water, alcohol, acids such as acetic acid, or mixtures thereof. Preferably, the protic solvent is water, a monovalent or divalent alcohol, or a mixture thereof. More preferably, the protic solvent is at least one solvent selected from the group consisting of water, methanol, ethanol, 1-propanol, 2-propanol, n-butanol, butanol isomers, n-pentanol, pentanol isomers, n-hexanol, and hexanol isomers, and even more preferably, at least one solvent selected from the group consisting of water, methanol, ethanol, 1-propanol, and 2-propanol.

[0037] The amount of the protic solvent in the solvent containing the protic solvent may be 100 to 50% by mass, 100 to 65% by mass, or 100 to 75% by mass, based on the total mass of the solvent containing the protic solvent.

[0038] The solvent 50 containing a protic solvent may also contain solvents other than the protic solvent. For example, it may contain the aprotic polar solvent.

[0039] The volume of solvent 50 containing a protic solvent is adjusted as appropriate, taking into consideration the depth d, the size of the resin particle deposition tank 1, and the volume of aromatic polysulfone solution to be discharged.

[0040] ≪Process (A)≫ The aromatic polysulfone solution is discharged from the nozzle 10's outlet 12 into a solvent 50 containing a protic solvent.

[0041] In step (A), the discharge port 12 of the nozzle 10 is located at a depth d in the solvent 50 containing a protic solvent that has been introduced into the resin particle deposition tank 1, and the aromatic polysulfone solution is discharged into the solvent 50 containing the protic solvent.

[0042] The depth d is adjusted so that the aromatic polysulfone solution discharged from the discharge port 12 is discharged into the solvent 50 containing a protic solvent. For example, the depth d is 1 cm or more.

[0043] The depth d may be adjusted by changing the fixed position of the nozzle 10, or by changing the volume of the solvent 50 containing the protic solvent.

[0044] In process (A), the discharge diameter of the nozzle 10 may be 0.5 mm or more and 15 mm or less, 0.5 mm or more and 11 mm or less, 0.7 mm or more and 11 mm or less, or 1 mm or more and 5 mm or less. If the discharge diameter of nozzle 10 is above the lower limit, the filtration efficiency can be improved. In addition, the precipitation rate of aromatic polysulfone particles can be improved, increasing the efficiency of the process. If the discharge diameter of nozzle 10 is below the upper limit, the aromatic polysulfone is less likely to clump together, and the amount of residual aprotic solvent in the resulting aromatic polysulfone particles can be reduced.

[0045] The aromatic polysulfone solution and the gas are supplied from the supply ports 11a and 11b of the nozzle 10, respectively.

[0046] The aromatic polysulfone solution and the gas supplied to the nozzle 10 are mixed inside the nozzle 10.

[0047] <Process (B)> The aromatic polysulfone solution is droplet-formed by the nozzle 10.

[0048] Step (A) and step (B) may be performed simultaneously. In other words, the aromatic polysulfone solution may be discharged into the solvent 50 containing the protic solvent from a discharge port 12 located at a depth d in the solvent 50 containing the protic solvent, while being formed into droplets. By discharging an aromatic polysulfone solution into a protic solvent while forming it into droplets, the filtration efficiency can be improved. Furthermore, scaling on the wall surface of the resin particle deposition tank can be prevented.

[0049] In step (A) described above, the method for delivering the aromatic polysulfone solution is not particularly limited, and conventionally known methods can be used. For example, it may be delivered by pump pressurization, or by a suction method that utilizes the flow of gas to draw it up.

[0050] In step (A) described above, the pressure at which the aromatic polysulfone solution is delivered is not particularly limited and can be appropriately adjusted depending on the concentration of aromatic polysulfone in the aromatic polysulfone solution and the temperature of the aromatic polysulfone solution. For example, when delivering the solution by pump pressurization, a conventionally known pump can be used.

[0051] In step (A) described above, the flow rate of the aromatic polysulfone solution and the flow rate of the gas can be adjusted by the flow rate ratio F. The flow rate ratio F is expressed by the following formula. Flow rate ratio F (g / L) = Flow rate of aromatic polysulfone solution (g / min) / Flow rate of gas (L / min)

[0052] The flow rate ratio F may be, for example, 0.05-30 g / L, 0.07-20 g / L, 0.07-15 g / L, 0.1-10 g / L, or 0.1-7.5 g / L.

[0053] In step (A) above, the solvent 50 containing the protic solvent may or may not be stirred by the stirrer 20. From the viewpoint of easily obtaining uniform aromatic polysulfone particles, it is preferable that the solvent 50 containing the protic solvent be stirred by the stirrer 20.

[0054] The aromatic polysulfone solution discharged into the solvent 50 containing a protic solvent precipitates as aromatic polysulfone particles in the solvent 50 containing the protic solvent. The aprotic solvent in the aromatic polysulfone solution is separated from the aromatic polysulfone particles precipitated in the solvent 50 containing the protic solvent into the solvent 50 containing the protic solvent.

[0055] Embodiments of the present disclosure include a filtration step for solid-liquid separation of the aromatic polysulfone particles precipitated in a solvent 50 containing a protic solvent and the aprotic solvent separated from the solvent 50 containing the protic solvent and the aromatic polysulfone particles. The aromatic polysulfone particles, the solvent 50 containing a protic solvent, and the aprotic solvent separated from the aromatic polysulfone particles are separated by solid-liquid separation using a filter cloth 40. The solvent 50 containing the protic solvent and the aprotic solvent separated from the aromatic polysulfone particles are discharged from the drainage channel 30 by opening the drainage valve 31.

[0056] <Effects and Effects> As described above, the method for producing aromatic polysulfone particles according to the above embodiment includes step (A) of discharging an aromatic polysulfone solution containing aromatic polysulfone and an aprotic solvent from a nozzle into a solvent containing a protic solvent, wherein the discharge port of the nozzle is immersed in the solvent containing the protic solvent. In this embodiment, the aprotic solvent is a good solvent for the aromatic polysulfone. The solvent containing the protic solvent is a poor solvent for the aromatic polysulfone, causing the aromatic polysulfone particles discharged from the discharge port of the nozzle to precipitate. This provides a method for producing aromatic polysulfone particles that has high filterability and can prevent scaling of the resin particle deposition tank wall. In step (A), the positioning of the nozzle 10's discharge port 12 in the solvent 50 containing a protic solvent is thought to increase the particle size of the resulting aromatic polysulfone particles, thereby improving filterability. Furthermore, in step (A), the positioning of the nozzle 10's discharge port 12 in the solvent 50 containing a protic solvent is thought to suppress the generation of fine aromatic polysulfone particles, thereby improving filterability.

[0057] According to the method for producing aromatic polysulfone particles according to the embodiments of this disclosure, aromatic polysulfone particles with a high proportion of large particle size are easily produced. The proportion of large particle size may be, for example, 65% by mass or more, 70% by mass or more, or 80-95% by mass.

[0058] [Method for evaluating the proportion of large particle sizes of aromatic polysulfone particles] The proportion of large particle sizes can be evaluated by the following method.

[0059] Aromatic polysulfone particles are sieved, and the weight of the aromatic polysulfone particles remaining on the sieve is measured. This weight is then divided by the total weight of the aromatic polysulfone particles sieved through the sieve to determine the percentage of large particles.

[0060] Sieve: Electric sieve ANF-30 manufactured by Nittokagaku Co., Ltd. Sieve opening: 710 μm Sieving time: 30 minutes

[0061] (Washing) Embodiments of this disclosure may include a step of washing the aromatic polysulfone particles obtained by the filtration step. The washing can be carried out by adding a solvent containing a protic solvent to the resin particle deposition tank and performing solid-liquid separation again using the filter cloth 40.

[0062] In the washing process described above, the temperature of the solvent containing the protic solvent may be below the boiling point of the solvent containing the protic solvent, for example, it may be 5 to 60°C or 10 to 40°C. In the washing process described above, the solvent containing the newly added protic solvent may or may not be stirred by the stirrer 20. It is preferable that the solvent containing the protic solvent be stirred by the stirrer 20.

[0063] (Drying) Embodiments of the present disclosure may include a step of drying the aromatic polysulfone particles obtained by the filtration step. The drying can be carried out by heating or reducing the pressure inside the resin particle precipitation tank 1, or by combining heating and reducing the pressure, or by transferring the solid-liquid separated aromatic polysulfone particles to another drying facility. In the drying process described above, the heating temperature can be arbitrarily set to a temperature below the heat resistance temperature of the aromatic polysulfone, and the degree of reduced pressure and drying time are not particularly limited and can be adjusted as appropriate.

[0064] <Other Embodiments>

[0065] In the above embodiment, an example was given in which the aromatic polysulfone solution is discharged into the solvent 50 containing a protic solvent from a discharge port 12 located at a depth d in the solvent 50 containing a protic solvent, while being droplet-formed. However, the embodiment is not limited to this. The aromatic polysulfone solution may be discharged into the solvent 50 containing a protic solvent without being droplet-formed. From the viewpoint of preventing the formation of aggregates and reducing the amount of residual aprotic solvent in the resulting aromatic polysulfone particles, it is preferable that the aromatic polysulfone solution is discharged into the solvent 50 containing a protic solvent while being droplet-formed.

[0066] The nozzle 10 may be a single-fluid nozzle or a multi-fluid nozzle with three or more fluids. Preferably, the nozzle 10 is a two-fluid nozzle or a multi-fluid nozzle with three or more fluids. If the nozzle 10 is a two-fluid nozzle or a multi-fluid nozzle with three or more fluids, the aromatic polysulfone solution and the gas can be mixed and discharged, or the aromatic polysulfone solution and the gas can be discharged and then mixed, making it less likely for the aromatic polysulfone to clump together and reducing the amount of residual aprotic solvent in the aromatic polysulfone particles. The aromatic polysulfone solution and the gas may be mixed with other components by a multi-fluid nozzle for three or more fluids.

[0067] The aromatic polysulfone solution supplied from the supply port 11a and the gas supplied from the supply port 11b may be mixed inside the nozzle 10 or outside the nozzle 10. Mixing outside the nozzle 10 means that the path of the supply port 11a and the path of the supply port 11b are each independent and lead to the discharge port 12, and the aromatic polysulfone solution and the gas are mixed after being discharged from their respective paths in the discharge port 12. From the viewpoint that resin clogging at the nozzle discharge port is unlikely to occur by gas-liquid mixing before the solvent containing a protic solvent comes into contact with the aromatic polysulfone solution, it is preferable that the aromatic polysulfone solution and the gas are mixed inside the nozzle 10.

[0068] [Evaluation of filtration performance] The filtration performance can be evaluated by the following method.

[0069] 15 g of aromatic polysulfone particles and 200 g of water are put into a filter, and pressure filtration is performed. Taking the start of pressurization as the start of filtration, the time (filtration time T) until the filtrate weight reaches 150 g is measured. The shorter the filtration time T, the higher the filtration performance.

[0070] The measurement conditions of the above filtration time T are shown below. Filter: ADVANTECH KST-47 Effective filtration area: 12 cm 2 ​​​​​​​​​​​​​​​The aromatic polysulfone used in the embodiments of this disclosure may have repeating units including a structure represented by the following formula (S-1). -ph 1 -SO2-ph 2 -O- …(S-1) [In formula (S-1), ph 1 and ph 2 These are, independently, phenylene groups that may have substituents.

[0072] In the above formula (S-1), ph 1 and ph 2 The phenylene group in this product may be a p-phenylene group, an m-phenylene group, or an o-phenylene group, but it is preferably a p-phenylene group.

[0073] The substituents that the phenylene group may have include alkyl groups, aryl groups, hydroxyl groups, acidic groups, and functional groups containing nitrogen atoms. The number of substituents on the phenylene group is independently 0 to 4, preferably 0 to 2, more preferably 0 to 1, and even more preferably 0. When the phenylene group has multiple substituents, the substituents may be the same or different.

[0074] Preferably, the alkyl group has 1 to 10 carbon atoms. Specifically, examples include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, t-butyl group, n-hexyl group, 2-ethylhexyl group, n-octyl group, and n-decyl group. Preferred aryl groups are those having 6 to 20 carbon atoms. Specifically, examples include phenyl, o-tolyl, m-tolyl, p-tolyl, 1-naphthyl, and 2-naphthyl groups. Examples of acidic groups include carboxyl groups (-COOH), sulfonic acid groups (-SO2OH), sulfinic acid groups (-SO2H), and phosphate groups (H2PO4-). Examples of functional groups containing a nitrogen atom include the amino group (-NH2) and the amide group (-CONH-).

[0075] Aromatic polysulfones may have repeating units containing a structure represented by the following formula (S-1-1). [ka] [In the formula, R 1 and R 2 Each is independently an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms. n1 and n2 are independently integers from 0 to 4, and if n1 or n2 is 2 or more, multiple R 1 and R 2 The groups may be identical or different. X is a single bond or a group derived from bisphenol or biphenol. n is an integer greater than or equal to 1.

[0076] In the above formula (S-1-1), R 1 and R 2 Examples include groups similar to the substituents that the phenylene group may have in formula (S-1) above.

[0077] The group derived from bisphenol among X is a divalent group obtained by removing a hydrogen atom from the two hydroxyl groups of bisphenol. Specifically, examples include groups derived from bisphenol A: (2,2-bis(4-hydroxyphenyl)propane), bisphenol AF: 2,2-bis(4-hydroxyphenyl)hexafluoropropane, bis(4-hydroxyphenyl)sulfide, bis(4-hydroxy-3-methylphenyl)sulfide, and bis(4-hydroxyphenyl) ethers, respectively. Among these, the group derived from bisphenol A is preferred.

[0078] The group derived from biphenol among X is a divalent group obtained by removing a hydrogen atom from the two hydroxyl groups of biphenol. Specifically, these include groups derived from 4,4'-biphenol (4,4'-dihydroxybiphenyl), 2,2'-dihydroxybiphenyl, 3,5,3',5'-tetramethyl-4,4'-dihydroxybiphenyl, 2,2'-diphenyl-4,4'-dihydroxybiphenyl, and 4,4'-dihydroxy-p-quaterphenyl, respectively. Among these, the group derived from 4,4'-biphenol is preferred.

[0079] X is preferably a single bond.

[0080] In formula (1) above, n is preferably between 5 and 600.

[0081] Aromatic polysulfones may have repeating units in their main chain that include a structure represented by the following formula (S-2) or a structure represented by the following formula (S-3). -ph 3 -R-ph 4 -O- …(S-2) -(ph 5 ) n -O- …(S-3) [In formula (S-2), ph 3 and ph 4 Each of these is independently a phenylene group which may have substituents. R is an alkylidene group, an oxygen atom, or a sulfur atom. In formula (S-3), ph 5 is a phenylene group which may have substituents. n is an integer from 1 to 3. If n is 2 or greater, there are multiple Ph groups. 5 They may be the same or different from each other.

[0082] ph 3 ph 4 and ph 5 For each of these, the ph in equation (S-1) 1 and ph 2 Examples of groups similar to the phenylene group in which substituents may be present include those similar to the phenylene group in the above example.

[0083] The alkylidene group mentioned above is preferably an alkylidene group having 1 to 5 carbon atoms, and examples include a methylene group, an ethylidene group, an isopropylidene group, and a 1-butylidene group.

[0084] In formula (S-3), n is preferably 1 or 2.

[0085] The aromatic polysulfone may be a single resin or a mixture of two or more resins.

[0086] (molecular weight) The weight-average molecular weight (Mw) of the aromatic polysulfone is preferably 1,000 to 150,000, more preferably 5,000 to 130,000, even more preferably 8,000 to 50,000, and still more preferably 10,000 to 35,000. If the weight-average molecular weight of the aromatic polysulfone is within the above range, the filterability will be improved. If the weight-average molecular weight of the aromatic polysulfone is below the upper limit of the above range, the formation of aggregates of aromatic polysulfone can be prevented.

[0087] The weight-average molecular weight (Mw) of aromatic polysulfone particles can be determined by gel permeation chromatography (GPC) measurement, as described below.

[0088] [Method for measuring the weight-average molecular weight of aromatic polysulfones] (Measurement sample) Eluent: 10 mmol / L lithium bromide-containing N,N-dimethylformamide solution. Sample preparation: Dissolve 0.050 g of aromatic polysulfone in 10 mL of eluent, and filter out the insoluble matter using a PTFE membrane filter with a pore size of 0.45 μm.

[0089] (Measurement conditions) Sample injection volume: 10 μL. Column (stationary phase): Two "TSKgel GMHHR-H" columns (7.8mm I.D. x 300mm) manufactured by Tosoh Corporation are connected in series. Column temperature: 40°C. Eluent (mobile phase): 10 mmol / L lithium bromide-containing N,N-dimethylformamide solution. Eluent flow rate: 0.8mL / min. Detectors: RI (differential refractometer) and LS (light scattering detector). Molecular weight calculation method: The molecular weight is calculated from the measurement results of a light scattering photometer (LS) (calculating the molecular weight assuming a dn / dc ratio of 0.187 for the sample).

[0090] Aromatic polysulfones may be manufactured by the method described later, or they may be commercially available products. Examples of commercially available products include (registered trademark) Sumika Excel PES 3600P, 4800P, and 5900P (all made from polyethersulfone, all manufactured by Sumitomo Chemical Co., Ltd.).

[0091] (Method for producing aromatic polysulfone) Aromatic polysulfones can be produced by polycondensing halogeno-aromatic sulfone compounds, which have two or three halogen atoms bonded to them, and dihydroxy aromatic compounds, etc., as monomers in an organic solvent in the presence of a base.

[0092] The aforementioned halogeno-aromatic sulfone compound is a compound having an aromatic ring, a sulfonyl group, and two or three halogen atoms bonded to the aromatic ring in one molecule. The aforementioned dihydroxy aromatic compound is a compound having an aromatic ring and two hydroxyl groups bonded to the aromatic ring in one molecule. Halogeno-aromatic sulfone compounds and dihydroxy-aromatic compounds correspond to the repeating units that make up aromatic polysulfones.

[0093] Aromatic polysulfones can be produced by using a compound represented by the following formula (mx-1) as a halogeno-aromatic sulfone compound and a compound represented by the following formula (my-1) as a dihydroxy aromatic compound. X 1 -ph1 -SO2-ph 2 -(X 2 ) m …(mx-1) HO-ph 1 -SO2-ph 2 -OH …(my-1) [In formula (mx-1), ph 1 and ph 2 Each of these is independently a phenylene group which may have substituents. 1 and X 2 These are, independently, halogen atoms. m is either 1 or 2. In formula (my-1), ph 1 and ph 2 These are, independently, phenylene groups that may have substituents.

[0094] The ph in equations (mx-1) and (my-1) 1 and ph 2 This is the ph in the above formula (S-1). 1 and ph 2 It is the same as this.

[0095] In formula (mx-1), X 1 and X 2 Each of these is independently a halogen atom. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms, with chlorine being preferred.

[0096] Compounds represented by formula (mx-1) include 4,4'-dichlorodiphenylsulfone, 4,4'-difluorodiphenylsulfone, and 4-chlorophenyl-3',4'-dichlorophenylsulfone.

[0097] Compounds represented by formula (my-1) include bis(4-hydroxyphenyl)sulfone, bis(4-hydroxy-3,5-dimethylphenyl)sulfone, and bis(4-hydroxy-3-phenylphenyl)sulfone.

[0098] If the aromatic polysulfone further has repeating units including the structure represented by formula (S-2) described above, the compound represented by formula (my-2) below is used as the dihydroxy aromatic compound. HO-ph 3 -R-ph 4 -OH …(my-2) [In formula (my-2), ph 3 and ph 4 Each of these is independently a phenylene group which may have substituents. R is an alkylidene group, an oxygen atom, or a sulfur atom.

[0099] In formula (my-2), ph 3 ph 4 And R is the ph in formula (S-2) described above. 3 ph 4 And are identical to R, respectively.

[0100] Compounds represented by formula (my-2) include bisphenol A: (2,2-bis(4-hydroxyphenyl)propane), bisphenol AF: 2,2-bis(4-hydroxyphenyl)hexafluoropropane, bis(4-hydroxyphenyl) sulfide, bis(4-hydroxy-3-methylphenyl) sulfide, and bis(4-hydroxyphenyl) ether.

[0101] If the aromatic polysulfone further has repeating units including the structure represented by formula (S-3) described above, the compound represented by formula (my-3) below is used as the dihydroxy aromatic compound. HO-(ph 5 ) n -OH …(my-3) [In formula (my-3), ph 5 is a phenylene group which may have substituents. n is an integer from 1 to 3. If n is 2 or greater, there are multiple ph 5 They may be the same or different from each other.

[0102] In formula (my-3), ph 5and n are the ph in formula (S-3) described above. 5 These are identical to and n, respectively.

[0103] Compounds represented by formula (my-3) include hydroquinone, resorcinol, catechol, phenylhydroquinone, 4,4'-dihydroxybiphenyl, 2,2'-dihydroxybiphenyl, 3,5,3',5'-tetramethyl-4,4'-dihydroxybiphenyl, 2,2'-diphenyl-4,4'-dihydroxybiphenyl, and 4,4'''-dihydroxy-p-quaterphenyl.

[0104] In the production of aromatic polysulfones, depending on the type of aromatic polysulfone to be produced, one halogeno-aromatic sulfone compound and one dihydroxy aromatic compound may be used alone, or two or more may be used in combination.

[0105] (Bases, organic solvents) The polycondensation of a halogeno-aromatic sulfone compound and a dihydroxy-aromatic compound is preferably carried out using an alkali metal salt of carbonate or an alkali metal hydroxide as the base. Furthermore, the polycondensation is preferably carried out in an organic solvent. More preferably, the polycondensation is carried out using an alkali metal salt of carbonate or an alkali metal hydroxide as the base and in an organic solvent.

[0106] Examples of alkali metal hydroxides include potassium hydroxide, sodium hydroxide, and cesium hydroxide. The hydroxide may be anhydrous, hydrated, or a mixture thereof.

[0107] The alkali metal salt of carbonic acid may be alkali carbonate (alkali metal carbonate), alkali bicarbonate (alkali hydrogen carbonate, alkali metal bicarbonate), or a mixture thereof.

[0108] Examples of alkaline carbonates include sodium carbonate, potassium carbonate, and cesium carbonate. Examples of alkaline bicarbonates include sodium bicarbonate, potassium bicarbonate, and cesium bicarbonate.

[0109] The boiling point of the organic solvent is preferably between 100°C and 400°C, and more preferably between 100°C and 350°C.

[0110] Examples of such organic solvents include ethers, esters, ketones, halogenated hydrocarbons, anisoles, sulfoxides such as dimethyl sulfoxide, amides such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, or N-ethyl-2-pyrrolidone, sulfones such as sulfolane, dimethyl sulfone, diethyl sulfone, diisopropyl sulfone, and diphenyl sulfone, and 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, etc.

[0111] The organic solvent is preferably at least one solvent selected from the group consisting of dimethyl sulfoxide, N,N-dimethylformamide, sulfolane, N-ethyl-2-pyrrolidone, N-methyl-2-pyrrolidone, N,N-dimethylacetamide, and 1,3-dimethyl-2-imidazolidinone.

[0112] Organic solvents may be used individually or in combination of two or more.

[0113] The reaction temperature for polycondensation is preferably between 180°C and 400°C, and the reaction time is preferably between 4 and 10 hours.

[0114] In another aspect, this disclosure further encompasses the following aspects:

[0115] [9] A method for producing aromatic polysulfone particles according to any one of the above [1] to [8], wherein the aprotic solvent is N-methyl-2-pyrrolidone, and the solvent containing the protic solvent of the aromatic polysulfone is water.

[0116]

[10] The method for producing aromatic polysulfone particles according to any one of the above [1] to [9], wherein the aromatic polysulfone is an aromatic polysulfone having repeating units including a structure represented by formula (S-1). -ph 1 -SO2-ph 2 -O- …(S-1) [In formula (S-1), ph 1 and ph 2 These are, independently, phenylene groups that may have substituents.

[0117]

[11] A method for producing aromatic polysulfone particles according to any one of the above [1] to

[10] , further comprising a filtration step of solid-liquid separation of aromatic polysulfone particles precipitated in a solvent containing a protic solvent and a non-protic solvent and a solvent containing a protic solvent separated from the aromatic polysulfone particles. [Examples]

[0118] The present disclosure will be explained below with reference to examples, but the present disclosure is not limited to the following examples.

[0119] In this embodiment, the process was carried out using an apparatus similar in nature to the aromatic polysulfone particle manufacturing apparatus shown in Figure 1, under the following conditions.

[0120] The nozzle outlet was positioned in a solvent solution containing a protic solvent. The outlet position was adjusted so that the depth d was 1 cm or more, relative to the surface level of the solvent solution containing the protic solvent. A two-fluid nozzle was used. Nitrogen was used as the gas supplied to the nozzle. Water at 20°C was used as the solvent containing a protic solvent. N-methyl-2-pyrrolidone (NMP) was used as the aprotic solvent.

[0121] • Aromatic polysulfone An aromatic polysulfone having repeating units containing the structure represented by the following formula (1) and having a weight-average molecular weight of 16,000 was used.

[0122] [ka]

[0123] The weight-average molecular weight (Mw) of the above aromatic polysulfones was determined by gel permeation chromatography (GPC) measurement, as described below.

[0124] [Method for measuring the weight-average molecular weight of aromatic polysulfones] (Measurement sample) Eluent: 10 mmol / L lithium bromide-containing N,N-dimethylformamide solution. Sample preparation: Aromatic polysulfone was dissolved in 10 mL of eluent to a concentration of 0.050 g, and insoluble matter was filtered off using a PTFE membrane filter with a pore size of 0.45 μm.

[0125] (Measurement conditions) Sample injection volume: 10 μL. Column (stationary phase): Two "TSKgel GMHHR-H" columns (7.8mm I.D. × 300mm) manufactured by Tosoh Corporation were connected in series. Column temperature: 40°C. Eluent (mobile phase): 10 mmol / L lithium bromide-containing N,N-dimethylformamide solution. Eluent flow rate: 0.8mL / min. Detectors: RI (differential refractometer) and LS (light scattering detector). Molecular weight calculation method: The molecular weight was calculated from the measurement results of a light scattering photometer (LS) (the dn / dc of the sample was set to 0.187 for molecular weight calculation).

[0126] The flow rates of the aromatic polysulfone solution and nitrogen were adjusted by the flow rate ratio F between the flow rates of the aromatic polysulfone solution and nitrogen. The flow rate ratio F between the aromatic polysulfone solution and nitrogen is expressed by the following formula: Flow rate ratio F (g / L) = Flow rate of aromatic polysulfone solution (g / min) / Flow rate of nitrogen (L / min)

[0127] [Example 1] The above aromatic polysulfone was dissolved in NMP to a concentration of 25% by mass to obtain an aromatic polysulfone solution. The resulting aromatic polysulfone solution was droplet-formed using a two-fluid nozzle and discharged into water. Specifically, the obtained aromatic polysulfone solution and nitrogen were supplied to two fluid nozzles, respectively. The flow rate ratio F of the aromatic polysulfone solution to nitrogen was adjusted to 0.1 g / L. Aromatic polysulfone particles were obtained by discharging an aromatic polysulfone solution, mixed with nitrogen inside a two-fluid nozzle, into agitated water using a nozzle with a discharge port diameter of 0.7 mm, and allowing the particles to precipitate in the water.

[0128] [Example 2] Aromatic polysulfone particles were obtained in the same manner as in Example 1, except that the concentration of aromatic polysulfone in the aromatic polysulfone solution was changed to 23% by mass, the nozzle diameter was changed to 1.8 mm, and the flow rate ratio F between the aromatic polysulfone solution and nitrogen was adjusted to 1.6 g / L.

[0129] [Example 3] Aromatic polysulfone particles were obtained in the same manner as in Example 2, except that the concentration of aromatic polysulfone in the aromatic polysulfone solution was changed to 37% by mass, and the flow rate ratio F between the aromatic polysulfone solution and nitrogen was adjusted to 0.57 g / L.

[0130] [Example 4] Aromatic polysulfone particles were obtained in the same manner as in Example 1, except that the concentration of aromatic polysulfone in the aromatic polysulfone solution was changed to 40% by mass, the discharge port diameter was changed to 4.5 mm, and the flow rate ratio F between the aromatic polysulfone solution and nitrogen was adjusted to 4.8 g / L.

[0131] [Example 5] Aromatic polysulfone particles were obtained in the same manner as in Example 1, except that the concentration of aromatic polysulfone in the aromatic polysulfone solution was changed to 15% by mass and the flow rate ratio F between the aromatic polysulfone solution and nitrogen was adjusted to 0.2 g / L.

[0132] [Example 6] Aromatic polysulfone particles were obtained in the same manner as in Example 1, except that the concentration of aromatic polysulfone in the aromatic polysulfone solution was changed to 30% by mass and the flow rate ratio F between the aromatic polysulfone solution and nitrogen was adjusted to 0.1 g / L.

[0133] [Comparative Example 1] Aromatic polysulfone particles were obtained in the same manner as in Example 1, except that the nozzle outlet position was adjusted to the gas phase, which is at least 1 cm away from the liquid surface. Scaling had occurred on the walls of the resin particle deposition tank.

[0134] [Comparative Example 2] Aromatic polysulfone particles were obtained in the same manner as in Example 2, except that the nozzle outlet position was adjusted to the gas phase at a distance of 1 cm or more from the liquid surface, the aromatic polysulfone was changed to an aromatic polysulfone with a weight-average molecular weight of 26,000, and the concentration of aromatic polysulfone in the aromatic polysulfone solution was changed to 15% by mass. Scaling had occurred on the walls of the resin particle deposition tank.

[0135] [Evaluation of filtration performance] The filterability of aromatic polysulfone particles was measured using the following method. 15 g of aromatic polysulfone particles obtained by the manufacturing methods of Examples 1-6 and Comparative Examples 1-2, along with 200 g of water, were placed in a filter and pressure filtration was performed. The time until the filtrate weight reached 150 g (filtration time T) was measured, with the start of pressurization defined as the start of filtration. A shorter filtration time T indicates higher filterability.

[0136] The measurement conditions for the filtration time T are shown below. Filter: ADVANTECH KST-47 Effective filtration area: 12 cm² 2 Filter cloth air permeability: 7,500 cm 3 / cm 2 ·min Filter cloth material: Polypropylene Applied pressure: 0.05 MPa

[0137] [Method for evaluating the proportion of large particle sizes of aromatic polysulfone particles] The particle size was measured using the following method.

[0138] Aromatic polysulfone particles were passed through a 710 μm sieve, and the mass of the aromatic polysulfone particles remaining on the sieve was measured. The ratio of large particle size was defined as the mass of aromatic polysulfone particles remaining on the sieve divided by the total mass of aromatic polysulfone particles passed through the sieve.

[0139] Sieve: Electric sieve ANF-30 manufactured by Nittokagaku Co., Ltd. Sieve opening: 710 μm Sieving time: 30 minutes

[0140] The measurement results are shown in Table 1.

[0141] [Table 1]

[0142] The manufacturing methods in Examples 1 to 6 were found to have significantly shorter filtration times and higher filterability compared to the manufacturing methods in Comparative Examples 1 to 2. In the manufacturing methods of Examples 1 to 6, it was confirmed that aromatic polysulfone particles with a higher proportion of large particle size were produced compared to the manufacturing methods of Comparative Examples 1 to 2. According to the manufacturing methods in Examples 1 to 6, it was confirmed that scaling did not occur on the walls of the resin particle deposition tank. [Explanation of symbols]

[0143] 1…Resin particle deposition tank, 10…Nozzle, 11a, 11b…Supply port, 12…Discharge port, 20…Agitator, 30…Drainage channel, 31…Drainage valve, 40…Filter cloth, 50…Solvent containing protic solvent, 51…Solvent liquid level containing protic solvent, 60…Gas phase, d…Depth

Claims

1. A method for producing aromatic polysulfone particles using an aromatic polysulfone solution containing an aromatic polysulfone and an aprotic solvent, The process includes step (A) of discharging the aromatic polysulfone solution from a nozzle into a solvent containing a protic solvent. A method for producing aromatic polysulfone particles, wherein in step (A), the discharge port of the nozzle is immersed in a solvent containing the protic solvent.

2. A method for producing aromatic polysulfone particles according to claim 1, wherein the gas and the aromatic polysulfone solution are mixed inside the nozzle.

3. A method for producing aromatic polysulfone particles according to claim 1 or 2, wherein the nozzle is a multifluid nozzle, and the method includes a step (B) of dropletizing the aromatic polysulfone solution using the multifluid nozzle.

4. The method for producing aromatic polysulfone particles according to claim 3, wherein the multi-fluid nozzle is a two-fluid nozzle.

5. A method for producing aromatic polysulfone particles according to claim 1 or 2, wherein the discharge port diameter of the nozzle is greater than 0.5 mm and 15 mm or less.

6. A method for producing aromatic polysulfone particles according to claim 1 or 2, wherein the concentration of aromatic polysulfone in the aromatic polysulfone solution is 15 to 50% by mass.

7. The method for producing aromatic polysulfone particles according to claim 1 or 2, wherein the aprotic solvent is at least one solvent selected from the group consisting of dimethyl sulfoxide, N,N-dimethylformamide, sulfolane, N-ethyl-2-pyrrolidone, N-methyl-2-pyrrolidone, N,N-dimethylacetamide, and 1,3-dimethyl-2-imidazolidinone.

8. The method for producing aromatic polysulfone particles according to claim 1 or 2, wherein the protic solvent is at least one solvent selected from the group consisting of water, methanol, ethanol, 1-propanol, 2-propanol, n-butanol, butanol isomers, n-pentanol, pentanol isomers, n-hexanol, and hexanol isomers.

Images