WO2012133640A1

WO2012133640A1 - Method for producing hydroxyl-terminated polysulfone

Info

Publication number: WO2012133640A1
Application number: PCT/JP2012/058342
Authority: WO
Inventors: 原田　博史
Original assignee: 住友化学株式会社
Priority date: 2011-03-31
Filing date: 2012-03-29
Publication date: 2012-10-04
Also published as: JP2012211289A

Abstract

The problem addressed by the present invention is to produce in a short time from a halogen-terminated polysulfone a polysulfone having a high proportion of hydroxyl termination. The present invention pertains to a method for producing a polysulfone having a hydroxyl group and/or a salt thereof at the termini by heating to a predetermined temperature a mixture containing a halogen-terminated polysulfone, a basic compound, and a solvent, and then admixing a metal compound that generates water at the predetermined temperature. Preferably, an alkali metal salt of carbonic acid is used as the basic compound; preferably, an aprotic solvent is used as the solvent; and preferably, a metal hydroxide is used as the metal compound that generates water.

Description

Process for producing hydroxy-terminated polysulfone

In the present invention, a polysulfone having a hydroxyl group and / or a salt thereof at the terminal (hereinafter referred to as “hydroxy-terminated polysulfone”) is produced from a polysulfone having a halogen atom at the terminal (hereinafter sometimes referred to as “halogen-terminated polysulfone”). On how to do.

Since polysulfone is excellent in heat resistance and chemical resistance, application to various applications including materials for electric and electronic parts is being studied. Of these, hydroxy-terminated polysulfones are preferably studied as paints, epoxy modifiers, and alloying agents by taking advantage of the reactivity of the hydroxy ends.

Polysulfone is usually produced by polycondensation of a dihalogenosulfone compound and a dihydroxy compound using a basic compound in a solvent. At that time, the dihydroxy compound is used in excess of the dihalogenosulfone compound. Hydroxy-terminated polysulfone can be obtained, but there is a problem that it is difficult to obtain a polymer having a high degree of polymerization. In order to solve such a problem, a method for producing a hydroxy-terminated polysulfone by hydrolyzing a halogen-terminated polysulfone that is easily obtained with a high degree of polymerization has been studied. For example, Patent Document 1 discloses a halogen-terminated polysulfone. Heating a mixture comprising polysulfone, water, a basic compound and a solvent is disclosed.

JP 2010-1447 A

In the method disclosed in Patent Document 1, it takes a long time for the reaction to obtain a polysulfone having a high hydroxy end ratio, and when the reaction temperature is raised to shorten the reaction time, water is consumed before the reaction. However, there is a problem that the reaction is difficult to proceed because it is easily distilled out of the system. Therefore, an object of the present invention is to provide a method capable of producing a polysulfone having a high hydroxy terminal ratio from a halogen-terminated polysulfone in a short time.

In order to achieve the above object, the present invention comprises heating a mixture containing a polysulfone having a halogen atom at a terminal, a basic compound, and a solvent to a predetermined temperature and mixing with a metal compound that generates water at the predetermined temperature. A process for producing a polysulfone having a hydroxyl group and / or a salt thereof at the terminal is provided.

According to the present invention, a polysulfone having a high hydroxy terminal ratio can be produced from a halogen-terminated polysulfone in a short time.

Polysulfone typically has a divalent aromatic group (residue obtained by removing two hydrogen atoms bonded to the aromatic ring from an aromatic compound), a sulfonyl group (—SO ₂ —), an oxygen atom, Is a resin having a repeating unit containing From the viewpoint of heat resistance and chemical resistance, the polysulfone preferably has a repeating unit represented by the following formula (1) (hereinafter sometimes referred to as “repeating unit (1)”). The repeating unit represented by (2) (hereinafter sometimes referred to as “repeating unit (2)”) and the repeating unit represented by the following formula (3) (hereinafter referred to as “repeating unit (3)”) And other repeating units may be included.

(1) -Ph ¹ -SO ₂ -Ph ² -O-

(Ph ¹ and Ph ² each independently represent a phenylene group. The hydrogen atoms in the phenylene group may each independently be substituted with an alkyl group, an aryl group, or a halogen atom.)

(2) -Ph ³ -R-Ph ⁴ -O-

(Ph ³ and Ph ⁴ each independently represent a phenylene group. The hydrogen atoms in the phenylene group may each independently be substituted with an alkyl group, an aryl group or a halogen atom. R represents an alkylidene. Represents a group, oxygen atom or sulfur atom.)

(3)-(Ph ⁵ ) _n —O—

(Ph ⁵ represents a phenylene group. The hydrogen atoms in the phenylene group may each independently be substituted with an alkyl group, an aryl group or a halogen atom. N represents an integer of 1 to 3. When n is 2 or more, a plurality of Ph ⁵ may be the same or different from each other.)

The phenylene group represented by any of Ph ¹ to Ph ⁵ may be a p-phenylene group, an m-phenylene group, or an o-phenylene group. From the viewpoints of properties and chemical resistance, a p-phenylene group is preferred. Examples of the alkyl group which may substitute a hydrogen atom in the phenylene group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an s-butyl group, a t- Examples thereof include a butyl group, an n-hexyl group, a 2-ethylhexyl group, an n-octyl group, and an n-decyl group, and the carbon number thereof is usually 1 to 10. Examples of the aryl group which may substitute a hydrogen atom in the phenylene group include a phenyl group, o-tolyl group, m-tolyl group, p-tolyl group, 1-naphthyl group and 2-naphthyl group. The carbon number is usually 6-20. When the hydrogen atom in the phenylene group is substituted with these groups, the number is usually 2 or less and preferably 1 or less for each phenylene group.

Examples of the alkylidene group as R include a methylene group, an ethylidene group, an isopropylidene group, and a 1-butylidene group, and the number of carbon atoms is usually 1 to 5.

The polysulfone preferably has a repeating unit (1) of 50 mol% or more, more preferably 80 mol% or more, more preferably 80 mol% or more based on the total of all repeating units from the viewpoint of heat resistance and chemical resistance. More preferably, it has substantially only the repeating unit (1). The polysulfone may have two or more repeating units (1) to (3) independently of each other.

Polysulfone can be produced by polycondensation of a dihalogenosulfone compound and a dihydroxy compound corresponding to the repeating unit constituting the polysulfone. For example, a resin having a repeating unit (1) uses a compound represented by the following formula (4) as a dihalogenosulfone compound (hereinafter sometimes referred to as “compound (4)”), and a dihydroxy compound represented by the following formula: It can be produced by using the compound represented by (5) (hereinafter sometimes referred to as “compound (5)”). The resin having the repeating unit (1) and the repeating unit (2) uses the compound (4) as the dihalogenosulfone compound and the compound represented by the following formula (6) as the dihydroxy compound (hereinafter referred to as “compound ( 6) ”may be used to produce the product. In addition, the resin having the repeating unit (1) and the repeating unit (3) uses the compound (4) as the dihalogenosulfone compound and the compound represented by the following formula (7) as the dihydroxy compound (hereinafter referred to as “compound ( 7) "may be used.

(4) X ¹ -Ph ¹ -SO ₂ -Ph ² -X ²

(X ¹ and X ² each independently represent a halogen atom. Ph ¹ and Ph ² are as defined above.)

(5) HO—Ph ¹ —SO ₂ —Ph ² —OH

(Ph ¹ and Ph ² are as defined above.)

(6) HO—Ph ³ —R—Ph ⁴ —OH

(Ph ³ , Ph ⁴ and R are as defined above.)

(7) HO— (Ph ⁵ ) _n —OH

(Ph ⁵ and n are as defined above.)

The polycondensation is preferably performed in a solvent using a basic compound. As the basic compound, an alkali metal carbonate is preferably used. The alkali metal salt of carbonic acid may be an alkali carbonate that is a normal salt, an alkali bicarbonate (an alkali hydrogen carbonate) that is an acidic salt, or a mixture of both. Are preferably sodium carbonate and potassium carbonate, and sodium bicarbonate and potassium bicarbonate are preferably used as the alkali bicarbonate. As the solvent, an aprotic solvent is preferably used. Among them, dimethyl sulfoxide, 1-methyl-2-pyrrolidone, sulfolane (1,1-dioxothyrane), 1,3-dimethyl-2-imidazolidinone, 1,3 A polar solvent such as diethyl-2-imidazolidinone, dimethyl sulfone, diethyl sulfone, diisopropyl sulfone, diphenyl sulfone, N, N-dimethylacetamide is preferably used.

In the present invention, halogen-terminated polysulfone is used as a raw material, and this is hydrolyzed to convert the terminal halogen atom into a hydroxyl group and / or a salt thereof (hereinafter sometimes referred to as “hydroxyl group”). To obtain a hydroxy-terminated polysulfone.

The halogen-terminated polysulfone can be obtained by using a dihalogenosulfone compound in excess of the dihydroxy compound in the polycondensation. The proportion of halogen atoms in all terminal groups of the halogen-terminated polysulfone is preferably 60 mol% or more, more preferably 80 mol% or more, and still more preferably 90 mol% or more.

The halogen-terminated polysulfone preferably has a reduced viscosity of 0.2 to 0.9 dl / g, more preferably 0.3 to 0.8 dl / g, still more preferably 0.35 to 0.76 dl / g, and particularly preferably. Is 0.4 to 0.6 dl / g. The reduced viscosity is a measure of the degree of polymerization. The higher the reduced viscosity of the halogen-terminated polysulfone, the higher the reduced viscosity of the resulting hydroxy-terminated polysulfone, that is, the higher the degree of polymerization, and the better the heat resistance, strength, and rigidity. However, if it is too high, the melting temperature and the melt viscosity are likely to be high, the temperature required for the molding is likely to be high, and the solubility in a solvent is likely to be low.

In the polycondensation, if no side reaction occurs, the closer the molar ratio of the dihalogenosulfone compound and the dihydroxy compound is to 1: 1, the greater the amount of alkali metal carbonate used, the higher the polycondensation temperature. In addition, the longer the polycondensation time, the higher the degree of polymerization of the resulting polysulfone and the higher the reduced viscosity. In practice, however, the substitution reaction of a halogeno group to a hydroxyl group or the like by a by-product alkali hydroxide or the like A side reaction such as depolymerization occurs, and the degree of polymerization of the resulting polysulfone tends to decrease and the reduced viscosity tends to decrease due to this side reaction. Therefore, in consideration of the degree of this side reaction, a polysulfone having a desired reduced viscosity can be obtained. The molar ratio of the dihalogenosulfone compound to the dihydroxy compound, the amount of alkali metal carbonate used, the polycondensation temperature and the polycondensation time It is preferable to integer.

In the present invention, the hydrolysis of the halogen-terminated polysulfone is carried out by heating a mixture containing the halogen-terminated polysulfone, the basic compound, and the solvent to a predetermined temperature and mixing the mixture with a compound that generates water at the predetermined temperature. Thereby, rapid hydrolysis at high temperature becomes possible, and polysulfone having a high hydroxy terminal ratio can be produced in a short time.

Examples of the basic compound include lithium carbonate, sodium carbonate, potassium carbonate, cesium carbonate, lithium hydrogen carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate and other alkali metal salts of carbonate, lithium hydroxide, sodium hydroxide, potassium hydroxide. Alkali metal hydroxides such as rubidium hydroxide and cesium hydroxide, alkali metal salts of acetic acid such as sodium acetate and potassium acetate, alkaline earths of carbonic acid such as calcium carbonate, magnesium hydrogen carbonate, calcium hydrogen carbonate and barium hydrogen carbonate Metal salt, hydroxide of alkaline earth metal such as magnesium hydroxide, hydroxide of quaternary ammonium such as tetramethylammonium hydroxide and tetraethylammonium hydroxide, tertiary amine such as trimethylamine and triethylamine, dimethylamine, Diechi Secondary amines, methylamine amine, primary amines ethylamine, and include ammonia, may be used two or more thereof. Among these, sodium carbonate, potassium carbonate, sodium hydroxide, and potassium hydroxide are preferable from the viewpoint of easy handling, and sodium carbonate and potassium carbonate are more preferable.

The amount of the basic compound used is usually 0.001 to 1 mol times, preferably 0.005 to 0.5 mol times, more preferably 0.005 to 0.1 mol times, still more preferably relative to the halogen-terminated polysulfone. Is 0.01 to 0.06 mole times. If the amount of the basic compound used is too large, the basic compound cannot be completely dissolved and the reaction becomes non-uniform, the basic compound remains in the polysulfone, or the polysulfone is easily colored. If the amount of basic compound used is too small, hydrolysis will not proceed easily. Here, the number of moles of halogen-terminated polysulfone is obtained by dividing the weight of halogen-terminated polysulfone by the formula weight (molecular weight per unit) of the repeating unit.

As the solvent, an aprotic solvent is preferably used because the solvation effect during the nucleophilic reaction is small, the reaction temperature can be set high with a high boiling point, and good solubility in halogen-terminated polysulfone is exhibited. Preferably an aprotic polar solvent is used. Among them, dimethyl sulfoxide, 1-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, sulfolane (1,1-dioxothyran), 1,3-dimethyl-2-imidazolidinone, 1, Polar solvents such as 3-diethyl-2-imidazolidinone, N-methyl-2-piperidone, dimethylsulfone, diethylsulfone, diisopropylsulfone, diphenylsulfone and the like are preferably used, and two or more of them may be used. Of these, dimethyl sulfoxide, N, N-dimethylformamide, N, N-dimethylacetamide, 1-methyl-2-pyrrolidone and diphenyl sulfone are preferable.

The amount of the solvent used is usually 1 to 20 times by mass, preferably 1 to 10 times by mass, more preferably 2 to 5 times by mass with respect to the halogen-terminated polysulfone. If the amount of the solvent used is too small, all of the polysulfone will not dissolve, or even if it is dissolved, the viscosity will be too high and operations such as stirring will be difficult. If the amount of the solvent used is too large, the reaction rate tends to be slow, and the yield during recovery tends to decrease.

Examples of metal compounds that generate water include hydroxides (M ^I OH, M ^II (OH) ₂ , M ^III (OH) _3, etc.), and oxide hydrates (M ^I ₂ O · H ₂ O). , M ^II O.H ₂ O, M ^III ₂ O ₃ .3H ₂ O, etc.), hydroxide hydrates, oxyhydroxide hydrates, and various metal salts including crystal water, Two or more of these may be used. Among them, aluminum hydroxide (crystalline alumina hydrate) is preferable, and examples thereof include gibbsite (Al ₂ O ₃ .H ₂ O (shown by Al (OH) ₃ ), bayerite (a), bayerite. (B), norstrandite, diaspore (Al ₂ O ₃ .H ₂ O (indicative formula AlO (OH))), boehmite, todite (5Al ₂ O ₃ .H ₂ O (indicative formula Al ₅ O ₇ ( OH))), pseudoboehmite (Al ₂ O ₃ .nH ₂ O (shown by the formula AlO (OH) .nH ₂ O)), and aluminogel (Al ₂ O _3. (H ₂ O) n).

The metal compound that generates water is preferably one that generates water at a temperature of 350 ° C. or lower. If the temperature at which water is generated is too high, the solvent that can raise the temperature to that temperature is limited, and at such a high temperature, polysulfone tends to decompose and color easily.

The amount of the metal compound used to generate water is preferably 0.01 to 10 mol times, more preferably 0.1 to 10 mol times, more preferably 0.1 to 10 mol times relative to the halogen-terminated polysulfone, expressed as the amount of water generated. The amount is preferably 0.1 to 6 mole times. If the amount of the metal compound that generates water is too large, the molecular weight of the resulting hydroxy-terminated polysulfone will decrease, or the amount of hydroxide residue will increase, making it difficult to recover and wash the polysulfone. When the amount of the metal compound that generates water is too small, the reaction does not proceed easily and the hydroxy terminal is difficult to be introduced.

The reaction temperature, that is, the heating temperature of the mixture, needs to be higher than the temperature at which the metal compound that generates water to be used generates water. Conversely, the metal compound that generates water has a temperature lower than the heating temperature of the mixture. It is necessary to use one that generates water. The heating temperature of the mixture is preferably 100 to 350 ° C, more preferably 150 to 300 ° C, still more preferably 200 to 300 ° C. When the heating temperature of the mixture is too high, the solvent that can be used is limited, and polysulfone is easily decomposed and colored. When the heating temperature of the mixture is too low, the reaction does not proceed easily and the hydroxy terminal is difficult to be introduced.

The reaction time is preferably 1 minute to 1 hour, more preferably 5 minutes to 1 hour, even more preferably 5 to 30 minutes, and particularly preferably 5 to 10 minutes. However, a polysulfone having a high hydroxy terminal ratio can be obtained, and the decomposition reaction and coloring of the polysulfone can be suppressed.

Since the reaction system contains a basic compound and is at a high temperature, the hydroxy-terminated polysulfone is easily oxidized. Therefore, the reaction atmosphere preferably does not contain oxygen, and the reaction is performed in an inert gas atmosphere such as nitrogen. Is preferred.

The hydroxy-terminated polysulfone is recovered from the reaction mixture by separating the basic compound and its residue and the residue of the metal compound that generates water from the reaction mixture by filtration or centrifugation, and the resulting hydroxy-terminated polysulfone solution is obtained. Mixing with a poor solvent for hydroxy-terminated polysulfone and precipitating the hydroxy-terminated polysulfone, or mixing the reaction mixture with a poor solvent for hydroxy-terminated polysulfone and precipitating the hydroxy-terminated polysulfone Also good. Examples of the poor solvent for the hydroxy-terminated polysulfone include alcohols such as methanol, ethanol, isopropanol and butanol, nitriles such as acetonitrile, and water, and two or more of them may be used. The poor solvent may contain a good solvent for hydroxy-terminated polysulfone such as a reaction solvent as long as the hydroxy-terminated polysulfone can be precipitated. An additive such as an agent may be added.

In order to obtain a polysulfone having a hydroxyl group at the terminal as the hydroxy-terminated polysulfone, it is preferable to contact with an acid after the reaction. The contact with the acid may be performed on the reaction mixture after the reaction, or may be performed with a poor solvent. It may be performed when the terminal polysulfone is precipitated or after the precipitation.

Examples of acids include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, perchloric acid, phosphoric acid, sulfurous acid, chromic acid, hypochlorous acid, hydrocyanic acid, hydrobromic acid, boric acid, acetic acid, formic acid, Examples thereof include organic acids such as acid, tartaric acid, stearic acid, naphthenic acid, picric acid, malic acid, and paratoluenesulfonic acid, and two or more thereof may be used.

The amount of acid used is preferably 0.001 to 2 mol times, more preferably 0.01 to 1 mol times, and still more preferably 0.02 to 0.5 mol times with respect to 1 mol of polysulfone. If the amount of the acid used is too small, the conversion of the hydroxyl group salt to the hydroxyl group tends to be insufficient, and if too much, it is not efficient.

It is preferable that the hydroxy-terminated polysulfone after precipitation recovery is washed with the poor solvent and then dried.

In the hydroxy-terminated polysulfone thus obtained, the proportion of hydroxyl groups in all terminal groups is preferably 60 mol% or more, more preferably 80 mol% or more, and still more preferably 90 mol% or more. The reduced viscosity is preferably 0.2 to 0.7 dl / g, more preferably 0.5 to 0.7 dl / g.

According to the present invention, the proportion of hydroxyl groups in all terminal groups is 60 mol% or more, the reduced viscosity is 0.5 to 0.7 dl / g, the proportion of hydroxy ends is high, and the degree of polymerization is high. Polysulfone can be obtained.

(Measurement of reduced viscosity of polysulfone)
About 1 g of polysulfone was dissolved in N, N-dimethylformamide to make its volume 1 dl, and the viscosity (η) of this solution was measured at 25 ° C. using an Ostwald type viscosity tube. Further, the viscosity (η ₀ ) of N, N-dimethylformamide as a solvent was measured at 25 ° C. using an Ostwald type viscosity tube. The specific viscosity ((η−η ₀ ) / η ₀ ) is determined from the viscosity (η) of the solution and the viscosity (η ₀ ) of the solvent, and this specific viscosity is determined by the concentration of the solution (about 1 g / dl). ) To determine the reduced viscosity (dl / g) of polysulfone.

[Measurement of number of terminal hydroxyl groups (mol / g) in polysulfone]
A predetermined amount of polysulfone is dissolved in dimethylformamide, an excess amount of paratoluenesulfonic acid is added, and then titrated with a 0.05 mol / L potassium methoxide / toluene / methanol solution using a potentiometric titrator. After neutralizing p-toluenesulfonic acid, the hydroxyl group is neutralized, and the amount (mol) of potassium methoxide required for neutralization of the hydroxyl group is divided by the predetermined amount (g) of the aromatic polysulfone resin. Determined by

[Measurement of the number of terminal halogen groups in polysulfone (mol / g)]
Here, an example in which the terminal halogen group is a chloro group will be described.
Using a 400 MHz nuclear magnetic resonance apparatus (“AL-400” manufactured by JEOL Ltd.), a proton NMR spectrum was measured for a deuterated DMSO solution of polysulfone having a concentration of 1 mg / ml at an accumulation count of 100 times. Bonded to the carbon adjacent to the carbon of the benzene ring to which the oxygen atom of the ether bond is bonded and the area (H _Cl ) of the proton signal (7.78 ppm) bonded to the carbon adjacent to the carbon of the benzene ring to which the chloro group is bonded The number of moles of chloro group per mole of repeating units (H _Cl / (H _O / 2)) is determined from the area (H _O ) of the proton signal (7.4 ppm), and the formula weight of the repeating unit Obtained by multiplying.

[Calculation of the proportion of halogen groups and the proportion of hydroxyl groups in all terminal groups in polysulfone]
It calculated | required by the following formula from the number of terminal hydroxyl groups in the polysulfone calculated | required previously, and the number of terminal halogen groups.
[Ratio of hydroxyl groups in all terminal groups] = [number of terminal hydroxyl groups] / ([number of terminal hydroxyl groups] + [number of terminal halogen groups])
[Proportion of halogen groups in all terminal groups] = [Number of terminal halogen groups] / ([Number of terminal hydroxyl groups] + [Number of terminal halogen groups])

[Measurement of heat loss of polysulfone]
<Heating loss>
Using a thermogravimetric analyzer (“TGA-50” from Shimadzu Corporation), about 10 mg of polysulfone was heated from room temperature to 600 ° C. under nitrogen flow at a rate of 10 ° C./min, and reduced by 10 mass%. The temperature to be measured was measured.

Reference Example 1 (Preparation of chloro-terminated polysulfone (1))
In a polymerization tank having a capacity of 2000 ml equipped with a stirrer, a nitrogen introduction tube, a thermometer, and a condenser with a receiver at the tip, 614.2 g (2.14 mol) of 4,4′-dichlorodiphenylsulfone, 4,4 After putting 525.0 g (2.10 mol) of '-dihydroxydiphenylsulfone and 784.0 g of diphenylsulfone as a polymerization solvent and raising the temperature to 180 ° C. while flowing nitrogen gas through the system, 300.8 g of anhydrous potassium carbonate The mixture was gradually heated to 290 ° C. and reacted at 290 ° C. for 2 hours. After completion of the reaction, the reaction solution was cooled to room temperature, and the solidified reaction mass was finely pulverized and then washed with warm water to remove potassium chloride. Further, washing with a mixed solvent of acetone and methanol was performed several times to remove diphenylsulfone as a polymerization solvent, and then washing with water, followed by drying at 150 ° C. by heating. The average particle diameter of the obtained powdery polysulfone was 500 μm. The reduced viscosity of this polysulfone was 0.52 dl / g.

Reference Example 2 (Preparation of chloro-terminated polysulfone (2))
In a polymerization tank having a capacity of 2000 ml equipped with a stirrer, a nitrogen introduction tube, a thermometer, and a condenser with a receiver at the tip, 4,9.3 ′ (2.12 mol) of 4,4′-dichlorodiphenylsulfone, 4,4 After putting 525.0 g (2.10 mol) of '-dihydroxydiphenylsulfone and 784.0 g of diphenylsulfone as a polymerization solvent and raising the temperature to 180 ° C. while flowing nitrogen gas through the system, 300.8 g of anhydrous potassium carbonate Add. The temperature was gradually raised to 290 ° C., and the reaction was carried out at 290 ° C. for 2 hours. After completion of the reaction, the reaction solution was cooled to room temperature, and the solidified reaction mass was finely pulverized and then washed with warm water to remove potassium chloride. Further, washing with a mixed solvent of acetone and methanol was performed several times to remove diphenylsulfone as a polymerization solvent, and then washing with water, followed by drying at 150 ° C. by heating. The average particle diameter of the obtained powdery polysulfone was 500 μm. The reduced viscosity of this polysulfone was 0.76 dl / g.

[Aluminum hydroxide]
As aluminum hydroxide, “CW-375HT” manufactured by Sumitomo Chemical Co., Ltd. was used. This aluminum hydroxide has an endothermic onset of 200 ° C. and an endothermic peak of 300 ° C. by DSC measurement at a temperature rising rate of 10 ° C./min, and the theoretically released water content is 34.6% by mass.

Example 1
In a 500 ml SUS separable flask equipped with a stirring blade, a cooling tube (Dimroth (water cooling)), a nitrogen introduction tube, and a thermometer, 166.6 g of chloro-terminated polysulfone (1) and diphenylsulfone (DPS) 230 as a solvent were used. 0.0 g was added, and the mixture was heated to 285 ° C. using an oil bath while stirring under a nitrogen gas flow, and melted and dissolved. The polysulfone concentration is 42% by mass. After dissolution and the internal temperature were stabilized, 1.98 g of finely powdered anhydrous potassium carbonate was added and dispersed, and then 5.0 g of aluminum hydroxide was added and stirred for 15 minutes.

Immediately after the stirring, the reaction solution was filtered hot at 150 ° C. to separate aluminum hydroxide residue and potassium carbonate residue, and the filtrate was added dropwise to 1000 ml of hydrochloric acid methanol having a concentration of 0.1% by mass to precipitate polysulfone. I let you. The filter paper was washed three times with 100 ml each of N-methylpyrrolidone, and the washing solution was dropped into the hydrochloric acid methanol as it was. The precipitated polysulfone was washed twice with 1000 ml of water and once with 1000 ml of methanol, and then recovered and vacuum dried at 150 ° C. The resulting polysulfone was in the form of a white powder. The yield of this polysulfone (recovered polysulfone mass / raw material polysulfone mass), reduced viscosity, ratio of chloro group and hydroxyl group in all terminal groups, and loss on heating are shown in Table 1.

Examples 2 and 3
The same operation as in Example 1 was carried out except that 1.85 g (Example 2) or 200 g (Example 3) of aluminum hydroxide was used. The results are shown in Table 1.

Example 4
The same procedure as in Example 1 was performed except that N-methylpyrrolidone was used as a reaction solvent, the reaction temperature was 200 ° C., and the reaction time was 60 minutes. The results are shown in Table 1.

Example 5
The reaction was conducted in the same manner as in Example 1 except that the reaction temperature was 300 ° C. The results are shown in Table 1.

Examples 6 and 7
The reaction was carried out in the same manner as in Example 1 except that the reaction time was 70 minutes (Example 6) or 40 minutes (Example 7). The results are shown in Table 1.

Example 8
The same procedure as in Example 1 was carried out except that chloro-terminated polysulfone (2) was used as the raw material polysulfone and the amount of diphenylsulfone used as the solvent was 330.0 g. The results are shown in Table 1.

Example 9
The reaction was conducted in the same manner as in Example 1 except that the reaction temperature was 360 ° C. The results are shown in Table 1.

Comparative Example 1
In a 500 ml glass separable flask equipped with a stirring blade, a cooling tube (Dimroth (water-cooled)), a nitrogen introduction tube, and a thermometer, 20.0 g of chloro-terminated polysulfone (1) and N-methylpyrrolidone (NMP) as a solvent 200 ml, 5.4 g of water, and 2.8 g of anhydrous potassium carbonate were added, the temperature was raised to 150 ° C. using an oil bath while stirring under a nitrogen gas flow, and the reaction was continued at that temperature for 15 minutes.

Immediately after completion of the reaction, the reaction solution was filtered while heated at 150 ° C. to remove potassium carbonate residue, and the filtrate was added dropwise to 500 ml of hydrochloric acid methanol having a concentration of 0.1% by mass to precipitate polysulfone. The filter paper was washed three times with 100 ml each of N-methylpyrrolidone, and the washing solution was dropped into the hydrochloric acid methanol as it was. The precipitated polysulfone was washed twice with 500 ml of water and once with 500 ml of methanol, and then recovered and vacuum dried at 150 ° C. The resulting polysulfone was in the form of a white powder. The yield of this polysulfone (recovered polysulfone mass / raw material polysulfone mass), reduced viscosity, ratio of chloro group and hydroxyl group in all terminal groups, and loss on heating are shown in Table 1.

Comparative Examples 2 and 3
The reaction was carried out in the same manner as Comparative Example 1 except that the reaction time was 60 minutes (Comparative Example 2) or 300 minutes (Comparative Example 3). The results are shown in Table 1.

Comparative Example 4
The same procedure as in Comparative Example 1 was performed except that 1.12 g of anhydrous potassium carbonate was used, 1.08 g of water was used, and the reaction time was 300 minutes. The results are shown in Table 1.

Comparative Example 5
The same procedure as in Example 1 was performed except that N-methylpyrrolidone was used as a reaction solvent, the reaction temperature was 80 ° C., and the reaction time was 60 minutes. The results are shown in Table 1.

Claims

A mixture containing a polysulfone having a halogen atom at a terminal, a basic compound, and a solvent is heated to a predetermined temperature and mixed with a metal compound that generates water at the predetermined temperature, and the terminal hydroxyl group and / or A method for producing polysulfone having the salt.
The manufacturing method according to claim 1, wherein the predetermined temperature is 100 to 350 ° C.
The production method according to claim 1, wherein the polysulfone having a halogen atom at the terminal is a polysulfone having a repeating unit represented by the following formula (1).
Formula (1): —Ph 1 —SO 2 —Ph 2 —O—
(Ph 1 and Ph 2 each independently represent a phenylene group. The hydrogen atoms in the phenylene group may each independently be substituted with an alkyl group, an aryl group, or a halogen atom.)
The method according to claim 1, wherein the basic compound is an alkali metal carbonate.
The production method according to claim 1, wherein the solvent is an aprotic solvent.
The method according to claim 1, wherein the metal compound is a metal hydroxide.
The production method according to claim 1, wherein the amount of the metal compound used is expressed in terms of the amount of water generated by the metal compound and is 0.01 to 10 mole times the polysulfone having a halogen atom at the terminal.
2. The production method according to claim 1, wherein the proportion of the halogen atoms in all terminal groups in the polysulfone having a halogen atom at the terminal is 60 mol% or more.
2. The production method according to claim 1, wherein a ratio of the hydroxyl group and a salt thereof to all terminal groups in the polysulfone having a hydroxyl group and / or a salt thereof at a terminal is 60 mol% or more.
The production method according to claim 1, wherein the reduced viscosity of the polysulfone having a halogen atom at a terminal is 0.2 to 0.9 (dl / g).
The production method according to claim 1, wherein the reduced viscosity of the polysulfone having a hydroxyl group and / or a salt thereof at a terminal is 0.2 to 0.7 dl / g.
Polysulfone having a hydroxyl group and / or salt ratio of 60 mol% or more in all terminal groups and a reduced viscosity of 0.5 to 0.7 dl / g.