Composite hollow fiber-type separation membranes, processes for the preparation thereof and their use

• US 4,664,669 A
• Filed: 02/28/1984
• Issued: 05/12/1987
• Est. Priority Date: 02/28/1983
• Status: Expired due to Term

• Current Assignee: Kuraray Company Limited
• Original Assignee: Kuraray Company Limited
• Inventors: Okamoto, Takehiko, Kawai, Syuji, Migaki, Takao, Ohyabu, Shuzo
• Primary Examiner(s): Apley, Richard J.
• Assistant Examiner(s): Beaucage, Gregg
• Application Number:
  US06/584,321
• Time in Patent Office: 1,169 Days
• Field of Search: 3/1, 427/245, 427/246, 427/244, 521/51, 521/63, 210/653, 210/654, 210/500.2, 604/4, 623/66, 623/11
• US Class Current: 428/304.4
• CPC Class Codes: B01D 69/02 characterised by their properties
• CPC Class Codes: B01D 69/08 Hollow fibre membranes manufacture of hollow fibres D01D5/24, D01F1/08
• CPC Class Codes: B01D 69/1214 Chemically bonded layers, e.g. cross-linking
• CPC Class Codes: B01D 69/1216 Three or more layers
• CPC Class Codes: Y10S 623/92 Method or apparatus for preparing or treating prosthetic
• CPC Class Codes: Y10T 428/249953 Composite having voids in a component [e.g., porous, cellular, etc.]

Abstract

A composite hollow fiber type separation membrane which has three layers comprising a selective separation layer, an ultra-microporous layer and a porous layer, said selective separation layer, said ultra-microporous layer, said porous layer being arranged in said order commencing from the inner surface of said hollow fiber membrane;

wherein said selective separation layer is formed on said ultra-microporous layer without penetrating into said ultra-microporous layer and has a non-porous, dense structure, the average thickness of said layer being 0.01-2μ, and the coefficient of variation in thickness thereof being less than or equal to 25%;

wherein said ultra-microporous layer has a surface in which the presence of pores cannot be confirmed by 24,000 × scanning electron microscopy, but which has a fluid permeability at least 10 times that of said selective separation layer, the thickness of said layer being less than or equal to 0.08μ; and

wherein said porous layer is a sponge structure comprising pores having a pore diameter of 0.1-1μ except for macro-voids and having a porosity of at least 50%, the thickness of said layer being 10-500μ.

Claims

1. A composite hollow fiber type gas separation membrane consisting essentially of a selective separation layer comprising a three dimensionally cross-linked polyorganosiloxane polymer, an ultra-microporous layer and a porous layer, said selective separation layer, said ultra-microporous layer and said porous layer being arranged in said order commencing from the inner surface of said hollow fiber membrane;

wherein said selective separation layer does not penetrate into said ultra-microporous layer, and has a non-porous, dense structure, the average thickness of said layer being 0.01-2μ

, and the coefficient of variation in thickness thereof being less than or equal to 25%;

wherein said ultra-microporous layer has a surface in which the presence of pores cannot be confirmed by 24,000×

scanning electron microscopy, but which has fluid permeability at least 10 times that of said selective separation layer, the thickness of said layer being less than or equal to 0.08μ

; and

wherein said porous layer is a sponge structure comprising pores having a pore diameter of 0.1-1μ

except for micro-voids and having a porosity of at least 50%, the thickness of said layer being 10-500μ

.

2. The composite hollow fiber type separation membrane according to claim 1 in which said ultra-microporous layer and said porous layer are layers comprising an aromatic polysulfone.