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US 5,089,135 AGranted
Carbon based porous hollow fiber membrane and method for producing same
AssigneeMitsubishi Rayon Co., Ltd.
InventorsHiroaki Yoneyama, Yoshihiro Nishihara
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AssigneeMitsubishi Rayon Co., Ltd.
InventorsHiroaki Yoneyama, Yoshihiro Nishihara
Estimating the term…
A carbon based porous hollow fiber membrane excellent in heat resistance wherein it has pores which continuously penetrate from inner wall surface to outer wall surface of the membrane, maximum value of pore radius obtained from pore volume differential curve is in 10-1000 nm, total pore volume is 0.1-1 cm.sup.3 /g, curvature radius at flexing is 10 cm or less, and temperature at which 10% by weight of the membrane is decomposed and which is measured by TGA is at least about 300.degree. C. and a method for producing the abovementioned carbon based porous hollow fiber membrane having excellent heat resistance, characterized by comprising mixing an acrylonitrile based polymer (A) containing 90-100 mol % of acrylonitrile unit, a heat decomposable polymer (B) which is heat decomposed at a temperature of 600.degree. C. or lower to become low in molecular weight, and a solvent (C), then spinning and drawing the mixture to obtain an acrylonitrile based hollow fiber, subjecting this hollow fiber to oxidizing treatment and then subjecting the hollow fiber to carbonizing treatment at 400.degree. C. or higher to make it porous.
A carbon based porous hollow fiber membrane excellent in heat resistance, having an internal diameter of 20 .mu.m to 1,000 .mu.m with a wall thickness of 2 .mu.m to 250 .mu.m, pores which continuously penetrate from inner wall surface to outer wall surface of the membrane, a pore size distribution such that the distribution curve of pore radius has a maximum value of 10-1000 nm, a total pore volume of 0.1-1 cm.sup.3 /g, and a curvature radius at flexing of 10 cm or less, and wherein the temperature at which 10% by weight of the membrane is decomposed as measured by TGA is at least about 300.degree. C.
A method for producing a carbon based porous hollow fiber membrane excellent in heat resistance, having pores which continuously penetrate from inner wall surface to outer wall surface of the membrane, a pore size distribution such that the distribution curve of pore radius has a maximum value of 10-1000 nm, a total pore volume of 0.1-1 cm.sup.3 g, and a curvature radius at flexing of 10 cm or less, and wherein the temperature at which 10% by weight of the membrane is decomposed as measured by TGA is at least about 300.degree. C., which comprises mixing an acrylonitrile based polymer (A) containing 90-100 mol% of acrylonitrile units, a heat decomposable polymer (B) which is heat decomposed at a temperature of 600.degree. C. or lower to become low in molecular weight, and a solvent (C), then spinning and drawing the mixture to obtain an acrylonitrile based hollow fiber, subjecting this hollow fiber to oxidizing treatment and then subjecting the hollow fiber to carbonizing treatment at 400.degree. C. or higher to make it porous.
Dependencies are inferred from the claim text.