Aromatic polysulfone resin and membrane thereof

Abstract

An aromatic polysulfone resin having a repeating unit represented by Formula (I) and a repeating unit represented by Formula (II), in which a ratio (m:n) of a molar content (m) of the repeating unit represented by Formula (I) to a molar content (n) of the repeating unit represented by Formula (II) is 1:2,000 to 1:200. ##STR00001## wherein hydrogen atoms of phenylene groups of Formulae (I) and (II) may be each independently substituted with an alkyl group, an aryl group, or a halogen atom.

Claims

1. An aromatic polysulfone resin comprising: a repeating unit represented by Formula (I); and a repeating unit represented by Formula (II), wherein a ratio (m:n) of a molar content (m) of the repeating unit represented by Formula (I) to a molar content (n) of the repeating unit represented by Formula (II) is 1:1000 to 1:300 ##STR00006## wherein hydrogen atoms of phenylene groups of Formulae (I) and (II) may be each independently substituted with an alkyl group, an aryl group, or a halogen atom.

2. A membrane comprising: the aromatic polysulfone resin according to claim 1.

3. The membrane according to claim 2, which is a porous membrane.

4. The aromatic polysulfone resin according to claim 1, wherein a reduced viscosity of the aromatic polysulfone resin is 0.3 dL/g to 0.9 dL/g.

5. The aromatic polysulfone resin according to claim 1, wherein a reduced viscosity of the aromatic polysulfone resin is 0.45 dL/g to 0.80 dL/g.

Description

EXAMPLES

(1) Examples of the present invention will be shown below, but the present invention is not limited thereto.

(2) In the examples, a porous membrane was used as an example of a membrane containing an aromatic polysulfone resin.

(3) [Measurement of Reduced Viscosity]

(4) 1 g of an aromatic polysulfone resin obtained in Manufacturing Examples 1 to 5 was dissolved in N,N-dimethylformamide such that a volume of the resulting solution was 1 dL, and a viscosity (η) of the solution was measured at 25° C. using an Ostwald viscosity tube. In addition, a viscosity (η.sub.0) of N,N-dimethylformamide as a solvent was measured at 25° C. using an Ostwald viscosity tube. Since the concentration of the solution is 1 g/dL, the value of the specific viscosity ((η−η.sub.0)/η.sub.0) is the value of the reduced viscosity in units of dL/g.

(5) [Measurement of Tensile Strength]

(6) 40 g of the resin obtained in Manufacturing Examples 1 to 5 and 160 g of N-methyl-2-pyrrolidone were stirred for 2 hours at 60° C. to obtain an aromatic polysulfone resin solution. Next, the solution was cast on a glass plate (thickness: 3 mm) using a film applicator such that a membrane thickness after a heat treatment was 30 μm. The obtained resin layer was heated at 80° C. by a high temperature hot air dryer to remove the solvent such that the residual solvent amount in the resin layer was 10 mass % or less. Then, a heat treatment was performed at 250° C. under a nitrogen atmosphere, and thus an aromatic polysulfone resin film was obtained.

(7) Using the obtained film, a tensile strength was measured based on ASTM D882 by Autograph manufactured by Shimadzu Corporation. The test was performed 5 times, and an average of the test results was used.

(8) [Measurement of Heat Shrinkage Rate]

(9) First, a porous membrane (sample) stored at 25° C. was cut into a length of 200 mm in a longitudinal direction, and a marked line was drawn at a position 150 mm away from an end portion of the sample in a longitudinal direction. Next, the sample was left in an autoclave and heat-treated for 30 minutes at a temperature of 121° C. without tension, and then the heated sample was transferred to a desiccator and cooled until the sample temperature reached 25° C. The distance from the end portion of the cooled sample to the marked line was measured, and a heat shrinkage rate was calculated by Formula (S1). The test was performed 3 times by changing the sample for each test, and an average of the test results was used.
Heat Shrinkage Rate (%)=[1−Distance (mm) from End Portion After Heating Treatment to Marked Line/Distance (mm) from End Portion Before Heating Treatment to Marked Line]×100  (S1)
<Manufacturing of Aromatic Polysulfone Resin>

(10) In the following manufacturing examples, a dichlorodiphenyl sulfone mixture obtained by mixing 4,4′-dichlorodiphenyl sulfone and 3,4′-dichlorodiphenyl sulfone was used as a dihalogenosulfone compound.

(11) As a dihydroxysulfone compound, a dihydroxydiphenyl sulfone mixture obtained by mixing 4,4′-dihydroxydiphenyl sulfone and 3,4′-dihydroxydiphenyl sulfone was used.

(12) A ratio (m:n) of a molar content (m) of a repeating unit (I) to a molar content (n) of a repeating unit (II) in the aromatic polysulfone resin was obtained from the amount (mol) of the raw material monomers charged. It was confirmed that all the raw material monomers used were consumed in the polymerization (polycondensation) reaction.

(13) The content of 3,4′-dichlorodiphenyl sulfone with respect to the total mass of the dichlorodiphenyl sulfone mixture was obtained by gas chromatography (may be abbreviated as GC) analysis under the following conditions. In addition, the content of 3,4′-dihydroxydiphenyl sulfone with respect to the total mass of the dihydroxydiphenyl sulfone mixture was obtained by GC analysis under the following conditions.

(14) (Conditions)

(15) Sample: Injection of 1 μL of a solution obtained by dissolving 0.1 g of the sample in 5 ml of acetone.

(16) Device: Gas chromatograph 6850 manufactured by Agilent Technologies, Inc.

(17) Column: GC column DB-5 manufactured by Agilent Technologies, Inc. (inner diameter: 0.25 mm, length: 30 m, membrane thickness: 1 μm)

(18) Column Temperature: 290° C.

(19) Detector: Hydrogen flame ionization type

(20) [Measurement of Content of 3,4′-Dichlorodiphenyl Sulfone]

(21) In an obtained spectrum, the total peak area detected after a holding time of 15 minutes was set to 100, and the peak area detected at the holding times of 15.4 minutes to 15.7 minutes was obtained by an area percentage method to calculate the content of 3,4′-dichlorodiphenyl sulfone with respect to the total mass of the dichlorodiphenyl sulfone mixture.

(22) [Measurement of Content of 3,4′-Dihydroxydiphenyl Sulfone]

(23) In the obtained spectrum, the sum of peak areas detected after a holding time of 14 minutes was set to 100, and the peak area detected at the holding times of 14.5 minutes to 14.8 minutes was obtained by an area percentage method to calculate the content of 3,4′-dihydroxydiphenyl sulfone with respect to the total mass of the dihydroxydiphenyl sulfone mixture.

Manufacturing Example 1

(24) A polymerization tank with a capacity of 500 mL provided with a stirrer, a nitrogen introduction pipe, a thermometer, and a condenser having a receiver at a tip thereof was charged with 100.1 g of 4,4′-dihydroxydiphenyl sulfone (content of 3,4′-dihydroxydiphenyl sulfone: 0 mass %), 117.7 g of 4,4′-dichlorodiphenyl sulfone (content of 3,4′-dichlorodiphenyl sulfone: 0.1 mass %), and 193.6 g of diphenyl sulfone as a polymerization solvent, and the temperature was raised to 180° C. during circulation of a nitrogen gas in the system. 56.5 g of potassium carbonate was added to the obtained solution. Then, the temperature was gradually raised to 290° C., and the reaction was carried out at 290° C. for 4 hours.

(25) Next, the obtained reaction liquid was cooled to room temperature (25° C.) to solidify the reaction product. The solid material was taken out and finely pulverized, and then the pulverized solid material was subjected to washing with warm water and washing with a mixed solvent of acetone and methanol several times. The washed solid material was heated and dried at 150° C. to obtain a white powder of an aromatic polysulfone resin.

(26) The reduced viscosity of the aromatic polysulfone resin was 0.60 (dL/g). The ratio (m:n) in the aromatic polysulfone resin was 1:1,000.

Manufacturing Example 2

(27) An aromatic polysulfone resin was obtained in the same manner as in Manufacturing Example 1, except that the content of 3,4′-dichlorodiphenyl sulfone with respect to the total amount of the dichlorodiphenyl sulfone mixture was changed to 0.3 mass %.

(28) The reduced viscosity of the aromatic polysulfone resin was 0.60 (dL/g). The ratio (m:n) in the aromatic polysulfone resin was 1:333.

Manufacturing Example 3

(29) An aromatic polysulfone resin was obtained in the same manner as in Manufacturing Example 1, except that the content of 3,4′-dichlorodiphenyl sulfone with respect to the total amount of the dichlorodiphenyl sulfone mixture was changed to 0 mass %.

(30) The reduced viscosity of the aromatic polysulfone resin was 0.60 (dL/g). The ratio (m:n) in the aromatic polysulfone resin was 0:100.

Manufacturing Example 4

(31) An aromatic polysulfone resin was obtained in the same manner as in Manufacturing Example 1, except that the content of 3,4′-dichlorodiphenyl sulfone with respect to the total amount of the dichlorodiphenyl sulfone mixture was changed to 0.7 mass %.

(32) The reduced viscosity of the aromatic polysulfone resin was 0.60 (dL/g). The ratio (m:n) in the aromatic polysulfone resin was 1:143.

Manufacturing Example 5

(33) An aromatic polysulfone resin was obtained in the same manner as in Manufacturing Example 1, except that the content of 3,4′-dichlorodiphenyl sulfone with respect to the total amount of the dichlorodiphenyl sulfone mixture was changed to 1.0 mass %.

(34) The reduced viscosity of the aromatic polysulfone resin was 0.60 (dL/g). The ratio (m:n) in the aromatic polysulfone resin was 1:100.

(35) <Manufacturing of Porous Membrane Containing Aromatic Polysulfone Resin>

Example 1

(36) 40 g of the aromatic polysulfone resin obtained in Manufacturing Example 1, 120 g of polyethylene glycol 400, and 140 g of N-methyl-2-pyrrolidone were put into a 500 mL separable flask, and stirred for 2 hours at 60° C. to obtain a slightly yellow aromatic polysulfone resin solution. The solution was applied to a glass plate having a thickness of 3 mm using a film applicator such that a resin layer thickness before drying was 300 μm, and immediately after the application, the glass plate was immersed in water. Then, the coating peeled from the glass plate was left in water for 30 minutes. Next, the coating was dried all night at 50° C. using a high temperature hot air dryer, and a porous membrane containing an aromatic polysulfone resin was obtained.

Example 2

(37) A porous membrane containing an aromatic polysulfone resin was obtained in the same manner as in Example 1, except that the aromatic polysulfone resin obtained in Manufacturing Example 2 was used.

Comparative Example 1

(38) A porous membrane containing an aromatic polysulfone resin was obtained in the same manner as in Example 1, except that the aromatic polysulfone resin obtained in Manufacturing Example 3 was used.

Comparative Example 2

(39) A porous membrane containing an aromatic polysulfone resin was obtained in the same manner as in Example 1, except that the aromatic polysulfone resin obtained in Manufacturing Example 4 was used.

Comparative Example 3

(40) A porous membrane containing an aromatic polysulfone resin was obtained in the same manner as in Example 1, except that the aromatic polysulfone resin obtained in Manufacturing Example 5 was used.

(41) Table 1 shows the reduced viscosities, ratios (m:n) and tensile strengths of the aromatic polysulfone resins of Examples 1 and 2 and Comparative Examples 1 to 3, and the heat shrinkage rates of the porous membranes.

(42) TABLE-US-00001 TABLE 1 Comparative Comparative Comparative Example 1 Example 2 Example 3 Example 1 Example 2 Aromatic Reduced 0.60 0.60 0.60 0.60 0.60 Polysulfone Viscosity (dL/g) Resin m:n 1:1,000 1:333 0:100 1:143 1:100 Evaluation Tensile Strength 85 86 87 88 85 Results (MPa) Heat Shrinkage 1.3 1.7 3.3 5.0 5.3 Rate (%)

INDUSTRIAL APPLICABILITY

(43) According to the present invention, it is possible to provide an aromatic polysulfone resin which is used to obtain a membrane having a low heat shrinkage rate and a membrane thereof, and thus the present invention is industrially extremely useful.