METHOD FOR PRODUCING AROMATIC POLYSULFONE

Abstract

A method for producing an aromatic polysulfone that includes subjecting 4,4′-dichlorodiphenylsulfone and an aromatic dihydroxy compound to a polycondensation reaction, wherein the median diameter (D50) of the 4,4′-dichlorodiphenylsulfone is not more than 1,000 μm.

Claims

1. A method for producing an aromatic polysulfone comprising subjecting 4,4′-dichlorodiphenylsulfone and an aromatic dihydroxy compound to a polycondensation reaction, wherein a median diameter (D50) of the 4,4′-dichlorodiphenylsulfone is not more than 1,000 μm.

2. (canceled)

3. The method for producing an aromatic polysulfone according to claim 1, wherein the polycondensation reaction is conducted at a temperature of not more than 250° C.

4. The method for producing an aromatic polysulfone according to claim 1, wherein the polycondensation reaction is conducted at a temperature of not more than 230° C.

5. The method for producing an aromatic polysulfone according to claim 1, wherein a blend ratio of the 4,4′-dichlorodiphenylsulfone, per 1 mol of the aromatic dihydroxy compound, is at least 0.98 mol but not more than 0.995 mol.

6. The method for producing an aromatic polysulfone according to claim 1, wherein the aromatic dihydroxy compound is 4,4′-dihydroxydiphenylsulfone.

7. The method for producing an aromatic polysulfone according to claim 1, wherein the polycondensation reaction is conducted in presence of an aprotic polar solvent, or in presence of an aprotic polar solvent and an additional solvent that forms an azeotropic mixture with water, and a boiling point of the aprotic polar solvent is not more than 250° C., or a boiling point of the additional solvent that forms an azeotropic mixture with water is not more than 250° C.

8. The method for producing an aromatic polysulfone according to claim 7, wherein the boiling point of the aprotic polar solvent is at least 140° C. but not more than 230° C., or the boiling point of the additional solvent that forms an azeotropic mixture with water is at least 80° C. but not more than 230° C.

9. The method for producing an aromatic polysulfone according to claim 7, wherein the aprotic polar solvent is N-methylpyrrolidone.

10. The method for producing an aromatic polysulfone according to claim 7, wherein a blend amount of the aprotic polar solvent, or the aprotic polar solvent and the additional solvent that forms an azeotropic mixture with water, is within a range from 80% by weight to 1,000% by weight relative to the total weight of the 4,4′-dichlorodiphenylsulfone and the aromatic dihydroxy compound.

Description

EXAMPLES

[0082] The present invention is described below in further detail using a series of specific examples. However, the present invention is in no way limited by the examples presented below.

<Measurement of Mn and Mw of Aromatic Polysulfone, Calculation of Mw/Mn>

[0083] The polystyrene-equivalent weight average molecular weight (Mw), the number average molecular weight (Mn) and the polydispersity (Mw/Mn) of the aromatic polysulfone were determined by GPC under the measurement conditions described below.

[Measurement Conditions]

[0084] Eluent: N,N-dimethylformamide solution containing 10 mM of lithium bromide

[0085] Sample preparation: The reaction liquid was diluted with the diluent in a ratio of 0.025 g of the aromatic polysulfone per 10 mL of the eluent, and the insoluble fraction (potassium chloride) was removed by filtration through a PTFE membrane filter with a pore size of 0.45 μm.

[0086] Sample injection volume: 10 μL

[0087] Columns (stationary phase): Two TSKgel Super HZM-M columns (4.6 mmø×150 mm) manufactured by Tosoh Corporation were connected in series.

[0088] Column temperature: 40° C.

Eluent (mobile phase): N,N-dimethylformamide solution containing 10 mM of lithium bromide

[0089] Eluent flow rate: 0.35 mL/min

[0090] Detector: UV detector (detection wavelength: 300 nm)

[0091] Molecular weight standards: standard polystyrenes

<Calculation of Median Diameter (D50) of 4,4′-dichlorodiphenylsulfone>

[0092] Using a Microtrac particle size analyzer (MT-3300EXII) manufactured by Nikkiso Co., Ltd., the particle size and volume fraction of all particles of the 4,4′-dichlorodiphenylsulfone were measured using the laser diffraction method. The volumes were totaled in sequence from the smallest particle diameter, and the particle diameter of the particle where the cumulative volume reached 50% relative to the total volume of all of the particles was deemed the median diameter (D50).

[0093] When measuring the particle sizes and volumes, the 4,4′-dichlorodiphenylsulfone was dispersed in a surfactant-containing aqueous solution prepared by adding three drops of a surfactant (Tween 20) to 40 mL of water, thus obtaining a dispersion, this dispersion was inserted into the sample injection port of the above Microtrac particle size analyzer, the volume of the sample was increased to about 200 mL inside the circulation tank of the analyzer using the above surfactant-containing aqueous solution, and measurements were then conducted. The sample size of the 4,4′-dichlorodiphenylsulfone was adjusted to conform with the appropriate concentration range displayed on the analyzer.

Comparative Example 1

[0094] In a polymerization tank fitted with a stirrer, a nitrogen inlet tube, a thermometer, and a condenser with a receiver attached to the top end, 58.0 parts by mass of potassium carbonate (1.05 mol per 1 mol of 4,4′-dihydroxydiphenylsulfone), 112 parts by mass of 4,4′-dichlorodiphenylsulfone with a median diameter (D50) of 1,820 μm (0.980 mol per 1 mol of 4,4′-dihydroxydiphenylsulfone) and 100 parts by mass of 4,4′-dihydroxydiphenylsulfone were mixed into 213 parts by mass of N-methyl-2-pyrrolidone (hereinafter sometimes referred to as “NMP”) at 30° C., and the temperature was then raised to 190° C. over a period of 1.5 hours. The temperature was then held at 190° C. to allow the 4,4′-dichlorodiphenylsulfone and the 4,4′-dihydroxydiphenylsulfone to undergo a polycondensation reaction.

[0095] The results of measuring the Mw and Mw/Mn values of the aromatic polysulfone after holding the temperature at 190° C. for 4 hours, 5 hours, and 6 hours are shown in Table 1.

Example 1-1

[0096] First, 4,4′-dichlorodiphenylsulfone with a median diameter (D50) of 1,820 μm was ground for 30 seconds using a small grinder (SM-1) manufactured by AS ONE Corporation to prepare a 4,4′-dichlorodiphenylsulfone with a median diameter (D50) of 184 μm.

[0097] With the exception of using the 4,4′-dichlorodiphenylsulfone with a median diameter (D50) of 184 μm, the 4,4′-dichlorodiphenylsulfone and the 4,4′-dihydroxydiphenylsulfone were subjected to a polycondensation reaction in a similar manner to Comparative Example 1.

[0098] The results of measuring the Mw and Mw/Mn values of the aromatic polysulfone after holding the temperature at 190° C. for 4 hours, 5 hours, and 6 hours are shown in Table 1.

Example 1-2

[0099] With the exception of using a 4,4′-dichlorodiphenylsulfone with a median diameter (D50) of 370 μm, the 4,4′-dichlorodiphenylsulfone and the 4,4′-dihydroxydiphenylsulfone were subjected to a polycondensation reaction in a similar manner to Comparative Example 1.

[0100] The results of measuring the Mw and Mw/Mn values of the aromatic polysulfone after holding the temperature at 190° C. for 4 hours, 5 hours, and 6 hours are shown in Table 1.

TABLE-US-00001 TABLE 1 D50 Reaction holding time: 4h Reaction holding time: 5h Reaction holding time: 6h (μm) Mw Mw/Mn Mw Mw/Mn Mw Mw/Mn Comparative 1820 41,500 4 52,400 4.3 56,600 4.4 Example 1 Example 184 44,100 4.1 54,600 4.4 59,600 4.5 1-1 Example 370 43,800 6.5 57,800 6.9 66,000 6.9 1-2

[0101] In Example 1-1 and Example 1-2 that used 4,4′-dichlorodiphenylsulfone with a median diameter (D50) of not more than 1,000 μm, the reaction rate was able to be increased compared with Comparative Example 1 that used 4,4′-dichlorodiphenylsulfone with a median diameter (D50) greater than 1,000 μm.

Comparative Example 2

[0102] With the exception of altering the amount of the 4,4′-dichlorodiphenylsulfone with a median diameter (D50) of 1,820 μm from 112 parts by mass to 114 parts by mass (0.995 mol per 1 mol of the 4,4′-dihydroxydiphenylsulfone), the 4,4′-dichlorodiphenylsulfone and the 4,4′-dihydroxydiphenylsulfone were subjected to a polycondensation reaction in a similar manner to Comparative Example 1.

[0103] The results of measuring the Mw and Mw/Mn values of the aromatic polysulfone after holding the temperature at 190° C. for 4 hours, 5 hours, and 6 hours are shown in Table 2.

Example 2-1

[0104] With the exception of using a 4,4′-dichlorodiphenylsulfone with a median diameter (D50) of 184 μm, the 4,4′-dichlorodiphenylsulfone and the 4,4′-dihydroxydiphenylsulfone were subjected to a polycondensation reaction in a similar manner to Comparative Example 2.

[0105] The results of measuring the Mw and Mw/Mn values of the aromatic polysulfone after holding the temperature at 190° C. for 4 hours, 5 hours, and 6 hours are shown in Table 2.

Example 2-1

[0106] With the exception of using a 4,4′-dichlorodiphenylsulfone with a median diameter (D50) of 370 μm, the 4,4′-dichlorodiphenylsulfone and the 4,4′-dihydroxydiphenylsulfone were subjected to a polycondensation reaction in a similar manner to Comparative Example 2.

[0107] The results of measuring the Mw and Mw/Mn values of the aromatic polysulfone after holding the temperature at 190° C. for 4 hours, 5 hours, and 6 hours are shown in Table 2.

TABLE-US-00002 TABLE 2 D50 Reaction holding time: 4h Reaction holding time: 5h Reaction holding time: 6h (μm) Mw Mw/Mn Mw Mw/Mn Mw Mw/Mn Comparative 1820 41,500 3.4 49,700 3.5  57,000 3.6 Example 2 Example 184 60,600 3.6 85,900 3.9 107,000 4.2 2-1 Example 370 64,500 6.4 91,500 7 111,100 7.3 2-2

[0108] In Example 2-1 and Example 2-2 that used 4,4′-dichlorodiphenylsulfone with a median diameter (DSO) of not more than 1,000 μm, the reaction rate was able to be significantly increased compared with Comparative Example 2 that used 4,4′-dichlorodiphenylsulfone with a median diameter (D50) greater than 1,000 μm.

INDUSTRIAL APPLICABILITY

[0109] The method for producing an aromatic polysulfone of the present invention enables the polycondensation reaction to proceed rapidly even at comparatively low temperatures, and is therefore very useful. The aromatic polysulfone obtained from the production method of the present invention exhibits excellent heat resistance and chemical resistance, and therefore use as a material for molded bodies in a variety of applications can be anticipated.