Ube Industries, Inc.

Harutoshi Hoshino

Toshimune Yoshinaga

Kenji Fukunaga

Tomonori Kanougi

Yoji Kase

Mikito Kashima

Toshikazu Machida

Yumiki Noda

Yoshihiro Kusuki

Fumio Adachi

Yukio Kaneko

Hideki Ichihashi

Ryoichi Takada

Shinji Asanuma

An asymmetric gas separation membrane made of an aromatic polyimide mainly containing repeating units having an ether bond which is heated at a temperature near a softening point (T) of the aromatic polyimide, and a method for separating methanol from a methanol-containing mixed organic vapor by allowing methanol to selectively permeate the asymmetric gas separation membrane using the membrane.

Asymmetric gas separation membrane and method for separating methanol from mixed organic vapor using the same

An asymmetric hollow fiber gas separation membrane obtained by subjecting an asymmetric hollow fiber polyimide membrane to a heat treatment having a maximum temperature of from 350 to 450&#xb0; C., wherein the asymmetric hollow fiber polyimide membrane is formed with a polyimide essentially having a repeating unit represented by a general formula (1); is excellent in a solvent resistance and a thermal stability, and as well has such a mechanical strength that a tensile elongation at break is not less than 10% as a hollow fiber membrane. In the general formula (1), 20 to 80 mol % of A is a tetravalent unit based on a biphenyl structure represented by formula (2), 20 to 80 mol % of A is a tetravalent unit based on a diphenylhexafluoropropane structure represented by formula (3), and 0 to 30 mol % of A is a tetravalent unit based on a phenyl structure represented by formula (4); and in the general formula (1), 30 to 70 mol % of R is a divalent unit represented by formula (5) and/or formula (6), and 30 to 70 mol % of R is a divalent unit having one or two other aromatic rings than formula (5) or (6),  

Solvent-resistant asymmetric hollow fiber gas separation membrane, and method for production thereof

Disclosed are a gas separation membrane and a gas separation method in which at least one species of organic vapor is separated and recovered from an organic vapor mixture using the gas separation membrane. The gas separation membrane is made of an aromatic polyimide composed of a tetracarboxylic acid component consisting of an aromatic ring-containing tetracarboxylic acid and a diamine component comprising 10 to 90 mol % of a combination of (B1) 3,4'-diaminodiphenyl ether and (B2) 4,4&#x2032;-diaminodiphenyl ether at a B1 to B2 molar ratio, B1/B2, ranging from 10/1 to 1/10, and 10 to 90 mol % of other aromatic diamine.

Polyimide gas separation membrane and gas separation method

A polyimide film made of a multicomponent polyimide comprising two or more different polyimide components including (A) a polyimide component A being raw materials of a polyimide A and/or a polyimidation product of the raw materials and (B) a polyimide component B being raw materials of a polyimide B and/or a polyimidation product of the raw materials. The polyimide components A and B are different, for example, such that the absolute difference between solubility parameter SPof the polyimide A and solubility parameter SPof the polyimide B, |SP-SP|, is 0.5 MPaor more. The polyimide film has markedly modified surface properties as compared with a polyimide film in which all the same raw materials as used in the film of the invention are randomly bonded to one another.

Polyimide film made of multicomponent polyimide and process of producing the same

The present invention relates to an asymmetric hollow-fiber gas separation membrane made of a polyimide having a specific repeating unit, an improved tensile elongation at break of 15% or more as a hollow-fiber membrane itself, an oxygen gas permeation rate (P') of 4.0&#xd7;10cm(STP)/cm&#xb7;sec&#xb7;cmHg or more and a gas ratio of permeation rate of oxygen to nitrogen (P&#x2032;/P&#x2032;) of 4 or more that are measured at 50&#xb0; C., a gas separation method and a gas separation membrane module using the asymmetric hollow-fiber gas separation membrane. In addition, the present invention relates to an asymmetric hollow-fiber gas separation membrane obtained by heat-treating the asymmetric hollow-fiber gas separation membrane at a maximum temperature of from 350 to 450&#xb0; C. The asymmetric hollow-fiber gas separation membrane has sufficient mechanical strength even after the heat-treatment at a maximum temperature of from 350 to 450&#xb0; C.

Asymmetric hollow-fiber gas separation membrane, gas separation method and gas separation membrane module

A crystalline polyesterpolyol having a number average molecular weight of 1,500 to 15,000 and obtainable from a polybasic carboxylic acid component and an aliphatic hydrocarbon diol component comprising 1,10-decanediol and/or 1,12-dodecanediol, and a hot-melt adhesive comprising a reaction product of a polyisocyanate and a polyesterpolyol, which contains a crystalline polyesterpolyol having a number average molecular weight of 1,500 to 15,000 and obtainable from a polybasic carboxylic acid component and an aliphatic hydrocarbon diol component comprising 1,10-decanediol and/or 1,12-dodecanediol are provided.

Crystalline polyesterpolyol and hot-melt adhesive

A cyanurate compound having three oxetane ring groups and represented by the general formula (1):

Cyanurate compound having three oxetane ring groups and organic hardening compositions containing same

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.

Growing community of inventors

Chiba, Japan

Harutoshi Hoshino