摘要:
A partially carbonized asymmetric hollow fiber separation membrane which is a hollow fiber separation membrane having an asymmetric structure obtained by partial carbonization of an aromatic polyimide hollow fiber separation membrane with an asymmetric structure, wherein the thickness of the aromatic polyimide hollow fiber membrane to be partially carbonized is 8-50 &mgr;m, the thickness of the hollow fiber separation membrane obtained by the carbonization is 8-45 &mgr;m, and the carbon content of the hollow fiber membrane obtained by partial carbonization is at least 1.05 times the carbon content of the aromatic polyimide hollow fiber membrane to be partially carbonized, and no greater than 90 wt %; also, a process for its production and a gas separation method employing it.
摘要:
A method of enhancing the gas-separation performance of an aromatic polyimide membrane with high reproducibility, by plasma-treating an asymmetric aromatic polyimide membrane comprising 80 to 100 molar % of at least one type of recurring units selected from those of the formulae (A) and (B) and 0 to 20 molar % of recurring units of the formula (C): ##STR1## in the formulae of which, R.sup.1, R.sup.2, R.sup.3 =an aromatic residue derived from an aromatic diamine compound and R=a tetravalent aromatic residue derived from an aromatic tetracarboxylic acid compound and different from tetravalent the aromatic tetracarboxylic acid residues appearing in the formulae (A) and (B), and has a helium gas-permeation rate [P.sub.He ] of 1.times.10.sup.-4 cm.sup.3 /cm.sup.2.sec.cmHg or more at 80.degree. C. and a ratio [P.sub.He ]/[P.sub.N2 ] of the helium gaspermeation rate [P.sub.He ] to a nitrogen gas-permeation rate [P.sub.N2 ] of 20 or more at 80.degree. C., in an atmosphere comprising ammonia.
摘要翻译:通过等离子体处理包含80-100摩尔%的至少一种选自式(A)的重复单元的重复单元的不对称芳族聚酰亚胺膜,提高了具有高再现性的芳族聚酰亚胺膜的气体分离性能的方法, 和(B)和(B)和(C)中的(B)和0至20摩尔%的式(C)的重复单元:其中R 1,R 2,R 3 = 衍生自芳族二胺化合物的芳族残基,R =衍生自芳族四羧酸化合物的四价芳香族残基,与式(A)和(B)中出现的四价芳香族四羧酸残基不同,具有氦气 - 在80℃下渗透速率[PHe]为1×10 -4 cm 3 / cm 2·sec·cmHg或更高,氦气渗透速率[PHe]与氮气渗透速率[PN2]的比[PHe] / [PN2] ]在80℃下在包含氨的气氛中为20以上。
摘要:
An aromatic polyimide double layered hollow filamentary membrane having an excellent heat resistance, chemical resistance, pressure-resistance, and gas-permeating and separating properties comprises (A) an aromatic imide polymer hollow filamentary microporous inner layer and (B) an aromatic imide polymer tubular filamentary asymmetric outer layer composed of (a) tubular filamentary microporous intermediate layer covering and united with the outside surface of the inner layer (A) and (b) a thin dense outside surface layer covering and united with the intermediate layer (a).
摘要:
A pervaporation separation method of water from an organic material aqueous solution at a high separating efficiency is effected by using a specific asymmetric separating membrane comprising a heat-resistant, solvent-soluble aromatic imide polymer prepared by the polymerization and imidization of an aromatic tetracarboxylic acid component comprising, as a principal ingredient, at least one biphenyl tetracarboxylic acid compound with an aromatic diamine component comprising a principal member selected from: ##STR1## and an additional member selected from another aromatic diamine compounds having 2 to 5 benzene ring structures and different from the diamine compounds (I) and (II).
摘要:
A pervaporation method of separating a liquid organic compound mixture at a high speed and efficiency through an aromatic polyimide asymmetric separating membrane produced from an aromatic tetracarboxylic acid component comprising at least 70 molar % of biphenyl or diphenylether tetracarboxylic dianhydride and an aromatic diamine component comprising 85 molar % or more of an aromatic diamine having 2 to 3 benzene ring structure, or 15 molar % or more of 9,10-di(aminophenyl)anthracene, di(aminophenoxy)diphenylsulfone, di(aminophenoxy)biphenyl or di(aminophenoxy)diphenylalkane compounds, or a mixture of 15 to 50 molar % of an aromatic diamine having alone benzene or pyridine ring structure and 50 to 85 molar % of an aromatic diamine having a 2 to 3 benzene ring structure.
摘要:
A porous membrane of an aromatic polyimide having an enhanced permeability of a gas or liquid is produced by a process comprising the steps of(1) preparing a dope solution of 3 to 30% by weight of an aromatic polyimide in a mixed solvent of (A) 100 parts by weight of a base solvent capable of dissolving 5% by weight or more of the polymeric acid and of evaporating at 30.degree. C. to 400.degree. C. and (B) 5 to 150 parts by weight of an additional liquid not capable of dissolving 3% by weight or more of the polyamic acid and capable of evaporating at a smaller evaporating rate than that of the base solvent at the above-mentioned evaporating temperature;(2) forming a thin layer of the dope solution at 0.degree. C. to 120.degree. C.; and(3) heating the dope solution layer at 30.degree. C. to 400.degree. C. so as to evaporate off the mixed solvent and to convert the polyamic acid to the corresponding polyimide.
摘要:
An asymmetric membrane is formed using a mixture of two or more different polymers including at least one type of polyimide. It is thereby possible to produce a gas separation membrane with low permeation resistance (a high permeation rate) for permeate gases passing through the porous layer of the membrane, which also maintains a practical level of mechanical strength of the membrane and has excellent water resistance and hot water resistance.
摘要:
A gas separating asymmetric membrane such as a gas separating asymmetric hollow fiber comprises an aromatic polyimide comprising recurring units of the formulae (I) and (II): ##STR1## wherein A.sup.1 is a tetravalent unit having a diphenylhexafluoropropane structure, A.sup.2 is a tetravalent unit having a benzene structure, and A.sup.3 is a divalent aromatic unit which is a unit derived from a sulfur atom-containing diamine such as diaminodibenzothiophene, diaminodiphenylenesulfone, diaminothioxanthene-5,5-dioxide or diaminothioxanthone-5,5-dioxide. The aromatic polyimide contains the recurring unit of the formula (I) in an amount of 40 to 90 molar % and the recurring unit of the formula (II) in an amount of 10 to 40 molar %. Further, a process for the preparation of the gas separating asymmetric hollow fiber membrane is also disclosed.
摘要:
A modified polymeric membrane having an excellent separating property is produced by applying, to a porous polymeric membrane, a volatile treating liquid containing a modifying agent which consists of at least one member selected from:(A) volatile dissolving organic liquids each capable of dissolving therein at least 1% by weight of the porous polymeric membrane at a temperature of 25.degree. C.; and(B) volatile shrinking organic liquids each capable of causing the porous polymeric membrane to shrink at a shrinkage of 3% or more.
摘要:
An aromatic polyimide composite membrane having an excellent gas-separating property is produced by a process comprising the steps of: coating at least one surface of a substrate consisting of an aromatic polyimide porous membrane with a solution of 0.05% to 10% by weight of an aromatic polyamic acid in a polar organic solvent, which is not capable of dissolving the polyimide porous membrane, at a temperature not exceeding 140.degree. C.; after a during drying the resultant thin coating layer of the polyamic acid solution, heating the resultant polyamic acid layer at a temperature of 150.degree. C. or more so as to convert the polyamic acid layer to the corresponding polyimide layer.