JP5358903B2 - Asymmetric hollow fiber gas separation membrane, gas separation method, and gas separation membrane module - Google Patents

Asymmetric hollow fiber gas separation membrane, gas separation method, and gas separation membrane module Download PDF

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JP5358903B2
JP5358903B2 JP2007191475A JP2007191475A JP5358903B2 JP 5358903 B2 JP5358903 B2 JP 5358903B2 JP 2007191475 A JP2007191475 A JP 2007191475A JP 2007191475 A JP2007191475 A JP 2007191475A JP 5358903 B2 JP5358903 B2 JP 5358903B2
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polyimide
hollow fiber
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gas separation
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洋次 加瀬
利宗 吉永
謙二 福永
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Ube Corp
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Abstract

<P>PROBLEM TO BE SOLVED: To provide an asymmetrical hollow fiber membrane for gas separation made of polyimide having a specific repetition unit that has its mechanical strength improved without affecting its separation performance badly, and a gas separation method for separating oxygen gas from a mixed gas containing oxygen gas and nitrogen gas by making the oxygen gas selectively permeate the asymmetrical hollow fiber membrane for gas separation. <P>SOLUTION: The invention relates to an asymmetrical hollow fiber membrane for gas separation made of polyimide having a specific repetition unit, a gas separation method using the asymmetrical hollow fiber membrane for gas separation and a membrane module for gas separation, the asymmetrical hollow fiber membrane for gas separation having an improved tensile break elongation as hollow fiber membrane of 15% or more, a permeation rate (P'<SB>O2</SB>) of oxygen gas at 50&deg;C of 4.0&times;10<SP>-5</SP>cm<SP>3</SP>(STP)/cm<SP>2</SP>*sec*cmHg or more and a ratio (P'<SB>O2</SB>/P'<SB>N2</SB>) of the permeation rate of oxygen gas to that of nitrogen gas of 4 or more. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

本発明は、特定の芳香族テトラカルボン酸成分と芳香族ジアミンとからなるポリイミドによって形成され、優れたガス分離性能と共に改良された機械的強度を併せ持った非対称中空糸ガス分離膜に関する。   The present invention relates to an asymmetric hollow fiber gas separation membrane which is formed of a polyimide composed of a specific aromatic tetracarboxylic acid component and an aromatic diamine and which has improved mechanical strength together with excellent gas separation performance.

特許文献１及び特許文献２には、特定の芳香族テトラカルボン酸成分と芳香族ジアミンとからなるポリイミドによって形成され、窒素ガスの透過速度に対する酸素ガスの透過速度の比が良好な非対称中空糸ガス分離膜が記載されている。   In Patent Document 1 and Patent Document 2, an asymmetric hollow fiber gas formed by a polyimide composed of a specific aromatic tetracarboxylic acid component and an aromatic diamine and having a good ratio of the oxygen gas permeation rate to the nitrogen gas permeation rate. A separation membrane is described.

特開平０３−２６７１３０号JP 03-267130 A 特開平０６−２５４３６７号JP 06-254367 A

前記特許文献１及び特許文献２の非対称中空糸ガス分離膜は、前述のとおり窒素ガスの透過速度に対する酸素ガスの透過速度の比（分離度）が良好であるなど、ガス分離性能は良好であったが中空糸膜としての機械的強度については改善の余地があった。本発明の目的は、特許文献１及び特許文献２に記載の反復単位からなるポリイミドと類似のポリイミドによって形成された非対称中空糸ガス分離膜でありながら、分離性能を大幅に低下させることなく、機械的強度を改善した非対称中空糸ガス分離膜を提供すること、更に前記非対称中空糸ガス分離膜を用いて酸素ガスと窒素ガスを含む混合ガスから選択的に酸素ガスを透過させてガス分離を行うガス分離方法を提供することである。   The asymmetric hollow fiber gas separation membranes of Patent Document 1 and Patent Document 2 have good gas separation performance, such as the ratio of the oxygen gas permeation rate to the nitrogen gas permeation rate (the degree of separation) as described above. However, there was room for improvement in mechanical strength as a hollow fiber membrane. The object of the present invention is an asymmetric hollow fiber gas separation membrane formed of a polyimide similar to the polyimide composed of repeating units described in Patent Document 1 and Patent Document 2, but without significantly reducing the separation performance. An asymmetric hollow fiber gas separation membrane with improved mechanical strength, and gas separation by selectively permeating oxygen gas from a mixed gas containing oxygen gas and nitrogen gas using the asymmetric hollow fiber gas separation membrane It is to provide a gas separation method.

本発明は、実質的に下記一般式（１）   The present invention substantially includes the following general formula (1):

Figure 0005358903
［但し、一般式（１）中のＡは、その２０〜８０モル％が式（２）
Figure 0005358903
 [However, A in the general formula (1) is 20 to 80 mol% of the formula (2)

Figure 0005358903
で示されるビフェニル構造に基く４価のユニットで、２０〜８０モル％が式（３）
Figure 0005358903
 Is a tetravalent unit based on the biphenyl structure represented by the formula (3):

Figure 0005358903
で示されるジフェニルヘキサフルオロプロパン構造に基づく４価のユニットで、０〜３０モル％が式（４）
Figure 0005358903
 Is a tetravalent unit based on the diphenylhexafluoropropane structure represented by the formula (4):

Figure 0005358903
で示されるフェニル構造に基づく４価のユニットで、一般式（１）中のＲは、その３０〜７０モル％が式（５）又は／及び式（６）
Figure 0005358903
 In the general formula (1), 30 to 70 mol% of the R in the general formula (1) is represented by the formula (5) or / and the formula (6).

Figure 0005358903
（式中、Ｒ１及びＲ２は水素原子または有機基であり、ｎは０、１又は２である。）
Figure 0005358903
 (Wherein R1 and R2 are a hydrogen atom or an organic group, and n is 0, 1 or 2)

Figure 0005358903
（式中、Ｒ１及びＲ２は水素原子または有機基であり、Ｘは−ＣＨ２−又は−ＣＯ−である。）
で示される２価のユニットで、３０〜７０モル％が式（７）
Figure 0005358903
 (In the formula, R 1 and R 2 are a hydrogen atom or an organic group, and X is —CH 2 — or —CO—.)
30-70 mol% is a divalent unit represented by the formula (7)

Figure 0005358903
（式中、Ｙは塩素原子又は臭素原子であり、ｎは１〜３である。）
で示されるビフェニル構造に基づく２価のユニットである。］からなる反復単位を有するポリイミドによって形成された非対称中空糸ガス分離膜であって、中空糸膜としての引張り破断伸度が１５％以上に改良された非対称中空糸ガス分離膜に関し、好ましくは、５０℃で測定した酸素ガスの透過速度（Ｐ’Ｏ２）が４．０×１０−５ｃｍ３（ＳＴＰ）／ｃｍ２・ｓｅｃ・ｃｍＨｇ以上且つ窒素ガスの透過速度に対する酸素ガスの透過速度の比（Ｐ’Ｏ２／Ｐ’Ｎ２）が４以上であることを特徴とする前記非対称中空糸ガス分離膜に関する。
Figure 0005358903
 (In the formula, Y is a chlorine atom or a bromine atom, and n is 1 to 3.)
It is a bivalent unit based on the biphenyl structure shown by these. An asymmetric hollow fiber gas separation membrane formed of a polyimide having a repeating unit consisting of: an asymmetric hollow fiber gas separation membrane having a tensile elongation at break of 15% or more as a hollow fiber membrane, The oxygen gas permeation rate ( P′O2 ) measured at 50 ° C. is 4.0 × 10 −5 cm 3 (STP) / cm 2 · sec · cmHg or more, and the ratio of the oxygen gas permeation rate to the nitrogen gas permeation rate ( P'O2 / P'N2 ) is 4 or more, The asymmetric hollow fiber gas separation membrane according to the above.

また、本発明は、前記非対称中空糸ガス分離膜の供給側に、酸素ガスと窒素ガスを含む混合ガスを接触させ、前記非対称中空糸ガス分離膜の透過側へ酸素ガスを選択的に透過させることによって、酸素ガスと窒素ガスを含む混合ガスから、酸素ガスが富化した混合ガスと窒素ガスが富化した混合ガスとを分離回収することを特徴とするガス分離方法に関し、特に、非対称中空糸ガス分離膜の内側を供給側とし、非対称中空糸ガス分離膜の外側を透過側とすることを特徴とする前記ガス分離方法に関する。   In the present invention, a mixed gas containing oxygen gas and nitrogen gas is brought into contact with the supply side of the asymmetric hollow fiber gas separation membrane, and oxygen gas is selectively permeated through the permeation side of the asymmetric hollow fiber gas separation membrane. In particular, the present invention relates to a gas separation method characterized by separating and recovering a mixed gas enriched with oxygen gas and a mixed gas enriched with nitrogen gas from a mixed gas containing oxygen gas and nitrogen gas. The present invention relates to the above gas separation method, characterized in that the inside of the yarn gas separation membrane is the supply side and the outside of the asymmetric hollow fiber gas separation membrane is the permeation side.

また、本発明は、前記非対称中空糸ガス分離膜の多数本を束ねた中空糸束と、前記中空糸束の少なくとも一方の端部において各中空糸膜を開口させた状態で包埋して固着した管板とを必須とした中空糸エレメントを、混合ガス供給口、非透過ガス排出口、及び透過ガス排出口を備えた容器内に、前記非対称中空糸ガス分離膜の内側の空間と外側の空間とが隔絶されるようにして収納したことを特徴とする中空糸ガス分離膜モジュールに関する。   The present invention also provides a hollow fiber bundle in which a large number of the asymmetric hollow fiber gas separation membranes are bundled, and is embedded and fixed in a state where each hollow fiber membrane is opened at at least one end of the hollow fiber bundle. The hollow fiber element, which is essential to the tube plate, is placed in a container having a mixed gas supply port, a non-permeate gas discharge port, and a permeate gas discharge port, and the space inside and outside the asymmetric hollow fiber gas separation membrane. The present invention relates to a hollow fiber gas separation membrane module characterized in that it is housed so as to be isolated from the space.

本発明によって、特許文献１及び特許文献２に記載の反復単位からなるポリイミドと類似のポリイミドによって形成された非対称中空糸ガス分離膜でありながら、分離性能を大幅に低下させることなく、機械的強度を改善した非対称中空糸ガス分離膜を提供すること、更に前記非対称中空糸ガス分離膜を用いて酸素ガスと窒素ガスを含む混合ガスから選択的に酸素ガスを透過させてガス分離を行うガス分離方法を提供することができる。   According to the present invention, the mechanical strength of the asymmetric hollow fiber gas separation membrane formed by a polyimide similar to the polyimide composed of repeating units described in Patent Document 1 and Patent Document 2 is greatly reduced without significantly reducing the separation performance. Asymmetric hollow fiber gas separation membrane with improved gas separation, and gas separation by selectively allowing permeation of oxygen gas from a mixed gas containing oxygen gas and nitrogen gas using the asymmetric hollow fiber gas separation membrane A method can be provided.

本発明の非対称中空糸ガス分離膜は、実質的に下記一般式（１）   The asymmetric hollow fiber gas separation membrane of the present invention has substantially the following general formula (1):

Figure 0005358903
［但し、一般式（１）中のＡは、その２０〜８０モル％が式（２）
Figure 0005358903
 [However, A in the general formula (1) is 20 to 80 mol% of the formula (2)

Figure 0005358903
で示されるビフェニル構造に基く４価のユニットで、２０〜８０モル％が式（３）
Figure 0005358903
 Is a tetravalent unit based on the biphenyl structure represented by the formula (3):

Figure 0005358903
で示されるジフェニルヘキサフルオロプロパン構造に基づく４価のユニットで、０〜３０モル％が式（４）
Figure 0005358903
 Is a tetravalent unit based on the diphenylhexafluoropropane structure represented by the formula (4):

Figure 0005358903
で示されるフェニル構造に基づく４価のユニットで、一般式（１）中のＲは、その３０〜７０モル％が式（５）又は／及び式（６）
Figure 0005358903
 In the general formula (1), 30 to 70 mol% of the R in the general formula (1) is represented by the formula (5) or / and the formula (6).

Figure 0005358903
（式中、Ｒ１及びＲ２は水素原子または有機基、好ましくは低級アルキル基であり、ｎは０、１又は２である。）
Figure 0005358903
 (Wherein R1 and R2 are a hydrogen atom or an organic group, preferably a lower alkyl group, and n is 0, 1, or 2)

Figure 0005358903
（式中、Ｒ１及びＲ２は水素原子または有機基、好ましくは低級アルキル基であり、Ｘは−ＣＨ２−又は−ＣＯ−である。）
で示される２価のユニットで、３０〜７０モル％が式（７）
Figure 0005358903
 (Wherein R1 and R2 are a hydrogen atom or an organic group, preferably a lower alkyl group, and X is —CH 2 — or —CO—).
30-70 mol% is a divalent unit represented by the formula (7)

Figure 0005358903
（式中、Ｙは塩素原子又は臭素原子であり、ｎは１〜３である。）
で示されるビフェニル構造に基づく２価のユニットである。］からなる反復単位を有するポリイミドによって形成される。
Figure 0005358903
 (In the formula, Y is a chlorine atom or a bromine atom, and n is 1 to 3.)
It is a bivalent unit based on the biphenyl structure shown by these. ] Formed of polyimide having a repeating unit consisting of

前記ポリイミドにおいて、テトラカルボン酸成分に由来する式（２）のビフェニル構造に基づく４価のユニットとしては、３，３’，４，４’−ビフェニルテトラカルボン酸やその酸無水物、２，３，３’，４’−ビフェニルテトラカルボン酸やその酸無水物等のビフェニルテトラカルボン酸類の残基を例示することができる。式（２）のビフェニル構造に基づく４価のユニットは、Ａ中の２０〜８０モル％、好ましくは２５〜７５モル％が好適である。この４価のユニットが少な過ぎると製膜が難しくなり、多過ぎるとガス透過速度が低下することがあるので好ましくない。   In the polyimide, as the tetravalent unit based on the biphenyl structure of the formula (2) derived from the tetracarboxylic acid component, 3,3 ′, 4,4′-biphenyltetracarboxylic acid or its acid anhydride, 2,3 Examples include residues of biphenyltetracarboxylic acids such as, 3 ′, 4′-biphenyltetracarboxylic acid and acid anhydrides thereof. The tetravalent unit based on the biphenyl structure of the formula (2) is 20 to 80 mol% in A, preferably 25 to 75 mol%. If the tetravalent unit is too small, film formation becomes difficult, and if it is too large, the gas permeation rate may decrease, which is not preferable.

また、式（３）のジフェニルヘキサフルオロプロパン構造に基づく４価のユニットとしては、２，２−ビス（３，４−ジカルボキシフェニル）ヘキサフルオロプロパンやその酸無水物等のジフェニルヘキサフルオロプロパン類の残基を例示することができる。式（３）のジフェニルヘキサフルオロプロパン構造に基づく４価のユニットは、Ａ中の２０〜８０モル％、好ましくは、２５〜７５モル％が好適である。この４価のユニットが少な過ぎるとガス透過速度が低下することがあり、多過ぎると機械的強度が低下するので好ましくない。   The tetravalent unit based on the diphenylhexafluoropropane structure of the formula (3) includes diphenylhexafluoropropanes such as 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane and acid anhydrides thereof. Can be exemplified. The tetravalent unit based on the diphenylhexafluoropropane structure of the formula (3) is 20 to 80 mol% in A, preferably 25 to 75 mol%. If the number of tetravalent units is too small, the gas permeation rate may decrease, and if too large, the mechanical strength decreases, which is not preferable.

また、式（４）のフェニル構造に基づく４価のユニットとしては、ピロメリット酸やその酸無水物等のピロメリット酸類の残基を例示することができる。式（４）のフェニル構造に基づく４価のユニットは、Ａ中の０〜３０モル％、好ましくは５〜２５モル％が好適である。このピロメリット酸類は、機械的強度を高めるうえで好適であるが、その量が多すぎると製膜時のポリマ−溶液が凝固したり、不安定になったりするので好ましくない。   Moreover, as a tetravalent unit based on the phenyl structure of Formula (4), the residue of pyromellitic acids, such as pyromellitic acid and its acid anhydride, can be illustrated. The tetravalent unit based on the phenyl structure of the formula (4) is suitably 0 to 30 mol%, preferably 5 to 25 mol% in A. These pyromellitic acids are suitable for increasing the mechanical strength, but if the amount is too large, the polymer solution during film formation is solidified or unstable, which is not preferable.

前記一般式（５）又は一般式（６）で示される構造からなる２価のユニットとしては、それぞれ、下記一般式（８）及び一般式（９）で示される芳香族ジアミンの残基を例示することができる。この２価のユニットは、一般式（１）のＲ中の３０〜７０モル％、好ましくは、３０〜６０モル％が好適である。このユニットはガス透過性の向上作用があるが、多過ぎると分離度が低下することがある。   Examples of the divalent unit having the structure represented by the general formula (5) or the general formula (6) include aromatic diamine residues represented by the following general formula (8) and general formula (9), respectively. can do. The divalent unit is preferably 30 to 70 mol%, preferably 30 to 60 mol% in R of the general formula (1). This unit has an effect of improving gas permeability, but if it is too much, the degree of separation may be lowered.

Figure 0005358903
（式中、Ｒ１及びＲ２は水素原子又は有機基であり、ｎは０、１又は２である。）
Figure 0005358903
 (In the formula, R1 and R2 are hydrogen atoms or organic groups, and n is 0, 1 or 2.)

Figure 0005358903
（式中、Ｒ１及びＲ２は水素原子又は有機基であり、Ｘは−ＣＨ2−又は−ＣＯ−である。）
Figure 0005358903
 (In the formula, R 1 and R 2 are a hydrogen atom or an organic group, and X is —CH 2 — or —CO—.)

前記一般式（８）で示される芳香族ジアミンとしては、一般式（８）のｎが０である下記一般式（１０）で示されるジアミノジベンゾチオフェン類、又は一般式（８）のｎが２である下記一般式（１１）で示されるジアミノジベンゾチオフェン＝５，５−ジオキシド類を好適に挙げることができる。   Examples of the aromatic diamine represented by the general formula (8) include diaminodibenzothiophenes represented by the following general formula (10) in which n in the general formula (8) is 0, or n in the general formula (8) is 2. Preferred examples include diaminodibenzothiophene = 5,5-dioxides represented by the following general formula (11).

Figure 0005358903
（式中、Ｒ１及びＲ２は水素原子又は有機基である。）
Figure 0005358903
 (In the formula, R1 and R2 are a hydrogen atom or an organic group.)

Figure 0005358903
（式中、Ｒ１及びＲ２は水素原子又は有機基である。）
Figure 0005358903
 (In the formula, R1 and R2 are a hydrogen atom or an organic group.)

前記のジアミノジベンゾチオフェン類（一般式（１０））としては、例えば３，７−ジアミノ−２，８−ジメチルジベンゾチオフェン、３，７−ジアミノ−２，６−ジメチルジベンゾチオフェン、３，７−ジアミノ−４，６−ジメチルジベンゾチオフェン、２，８−ジアミノ−３，７−ジメチルジベンゾチオフェン、３，７−ジアミノ−２，８−ジエチルベンゾチオフェン、３，７−ジアミノ−２，６−ジエチルベンゾチオフェン、３，７−ジアミノ−４，６−ジエチルベンゾチオフェン、３，７−ジアミノ−２，８−ジプロピルジベンゾチオフェン、３，７−ジアミノ−２，６−ジプロピルジベンゾチオフェン、３，７−ジアミノ−４，６−ジプロピルジベンゾチオフェン、３，７−ジアミノ−２，８−ジメトキシジベンゾチオフェン、３，７−ジアミノ−２，６−ジメトキシジベンゾチオフェン、３，７−ジアミノ−４，６−ジメトキシジベンゾチオフェンなどを挙げることができる。   Examples of the diaminodibenzothiophenes (general formula (10)) include 3,7-diamino-2,8-dimethyldibenzothiophene, 3,7-diamino-2,6-dimethyldibenzothiophene, and 3,7-diamino. -4,6-dimethyldibenzothiophene, 2,8-diamino-3,7-dimethyldibenzothiophene, 3,7-diamino-2,8-diethylbenzothiophene, 3,7-diamino-2,6-diethylbenzothiophene 3,7-diamino-4,6-diethylbenzothiophene, 3,7-diamino-2,8-dipropyldibenzothiophene, 3,7-diamino-2,6-dipropyldibenzothiophene, 3,7-diamino -4,6-dipropyldibenzothiophene, 3,7-diamino-2,8-dimethoxydibenzothiophene, 3 7-diamino-2,6-dimethoxy dibenzothiophene, etc. 3,7-diamino-4,6-dimethoxy-dibenzothiophene and the like.

前記のジアミノジベンゾチオフェン＝５，５−ジオキシド類（一般式（１１））としては、例えば３，７−ジアミノ−２，８−ジメチルジベンゾチオフェン＝５，５−ジオキシド、３，７−ジアミノ−２，６−ジメチルジベンゾチオフェン＝５，５−ジオキシド、３，７−ジアミノ−４，６−ジメチルジベンゾチオフェン＝５，５−ジオキシド、２，８−ジアミノ−３，７−ジメチルジベンゾチオフェン＝５，５−ジオキシド、３，７−ジアミノ−２，８−ジエチルベンゾチオフェン＝５，５−ジオキシド、３，７−ジアミノ−２，６−ジエチルベンゾチオフェン＝５，５−ジオキシド、３，７−ジアミノ−４，６−ジエチルベンゾチオフェン＝５，５−ジオキシド、３，７−ジアミノ−２，８−ジプロピルジベンゾチオフェン＝５，５−ジオキシド、３，７−ジアミノ−２，６−ジプロピルジベンゾチオフェン＝５，５−ジオキシド、３，７−ジアミノ−４，６−ジプロピルジベンゾチオフェン＝５，５−ジオキシド、３，７−ジアミノ−２，８−ジメトキシジベンゾチオフェン＝５，５−ジオキシド、３，７−ジアミノ−２，６−ジメトキシジベンゾチオフェン＝５，５−ジオキシド、３，７−ジアミノ−４，６−ジメトキシジベンゾチオフェン＝５，５−ジオキシドなどを挙げることができる。   Examples of the diaminodibenzothiophene = 5,5-dioxides (general formula (11)) include 3,7-diamino-2,8-dimethyldibenzothiophene = 5,5-dioxide and 3,7-diamino-2. , 6-Dimethyldibenzothiophene = 5,5-dioxide, 3,7-diamino-4,6-dimethyldibenzothiophene = 5,5-dioxide, 2,8-diamino-3,7-dimethyldibenzothiophene = 5,5 Dioxide, 3,7-diamino-2,8-diethylbenzothiophene = 5,5-dioxide, 3,7-diamino-2,6-diethylbenzothiophene = 5,5-dioxide, 3,7-diamino-4 , 6-Diethylbenzothiophene = 5,5-dioxide, 3,7-diamino-2,8-dipropyldibenzothiophene = 5,5-dioxide Xoxide, 3,7-diamino-2,6-dipropyldibenzothiophene = 5,5-dioxide, 3,7-diamino-4,6-dipropyldibenzothiophene = 5,5-dioxide, 3,7-diamino- 2,8-dimethoxydibenzothiophene = 5,5-dioxide, 3,7-diamino-2,6-dimethoxydibenzothiophene = 5,5-dioxide, 3,7-diamino-4,6-dimethoxydibenzothiophene = 5 Examples include 5-dioxide.

前記の一般式（９）において、Ｘが−ＣＨ2−であるジアミノチオキサンテン−１０，１０−ジオン類としては、例えば３，６−ジアミノチオキサンテン−１０，１０−ジオン、２，７−ジアミノチオキサンテン−１０，１０−ジオン、３，６−ジアミノ−２，７−ジメチルチオキサンテン−１０，１０−ジオン、３，６−ジアミノ−２，８−ジエチル−チオキサンテン−１０，１０−ジオン、３，６−ジアミノ−２，８−ジプロピルチオキサンテン−１０，１０−ジオン、３，６−ジアミノ−２，８−ジメトキシチオキサンテン−１０，１０−ジオン、等を挙げることができる。 Examples of the diaminothioxanthene-10,10-diones where X is —CH 2 — in the general formula (9) include 3,6-diaminothioxanthene-10,10-dione and 2,7-diamino. Thioxanthene-10,10-dione, 3,6-diamino-2,7-dimethylthioxanthene-10,10-dione, 3,6-diamino-2,8-diethyl-thioxanthene-10,10-dione, Examples include 3,6-diamino-2,8-dipropylthioxanthene-10,10-dione, 3,6-diamino-2,8-dimethoxythioxanthene-10,10-dione, and the like.

前記の一般式（９）において、Ｘが−ＣＯ−であるジアミノチオキサンテン−９，１０，１０−トリオン類としては、例えば３，６−ジアミノ−チオキサンテン−９，１０，１０−トリオン、２，７−ジアミノ−チオキサンテン−９，１０，１０−トリオンなどを挙げることができる。   Examples of the diaminothioxanthene-9,10,10-triones in which X is —CO— in the general formula (9) include 3,6-diamino-thioxanthene-9,10,10-trione, 2 , 7-diamino-thioxanthene-9,10,10-trione.

また、ジアミン成分に由来する式（７）のビフェニル構造に基づく２価のユニットとしては、２，２’，５，５’−テトラクロロベンジジン、３，３’，５，５’−テトラクロロベンジジン、３，３’−ジクロロベンジジン、２，２’−ジクロロベンジジン、２，２’，３，３’，５，５’−ヘキサクロロベンジジン、２，２’，５，５’−テトラブロモベンジジン、３，３’，５，５’−テトラブロモベンジジン、３，３’−ジブロモベンジジン、２，２’−ジブロモベンジジン、２，２’，３，３’，５，５’−ヘキサクロロベンジジン等のベンジジン類の残基を例示することができる。これらのなかでも式（７）のＹが塩素原子であるベンジジンで、ｎが２のものが透過速度、分離度等からみて特に好適である。式（７）のビフェニル構造に基づく２価のユニットは、一般式（１）のＲ中の３０〜７０モル％、好ましくは、３０〜６０モル％が好適である。このベンジジン類は、分離度の向上に寄与するが、その量が多過ぎるとポリマ−が不溶になって製膜が困難になるので好ましくない。   Examples of the divalent unit based on the biphenyl structure of the formula (7) derived from the diamine component include 2,2 ′, 5,5′-tetrachlorobenzidine and 3,3 ′, 5,5′-tetrachlorobenzidine. 3,3′-dichlorobenzidine, 2,2′-dichlorobenzidine, 2,2 ′, 3,3 ′, 5,5′-hexachlorobenzidine, 2,2 ′, 5,5′-tetrabromobenzidine, 3, , 3 ', 5,5'-tetrabromobenzidine, 3,3'-dibromobenzidine, 2,2'-dibromobenzidine, 2,2', 3,3 ', 5,5'-hexachlorobenzidine Can be exemplified. Of these, benzidine wherein Y in the formula (7) is a chlorine atom and n is 2 is particularly preferable in view of permeation rate, degree of separation, and the like. The divalent unit based on the biphenyl structure of the formula (7) is 30 to 70 mol%, preferably 30 to 60 mol% in R of the general formula (1). These benzidines contribute to the improvement of the degree of separation, but if the amount is too large, the polymer becomes insoluble and film formation becomes difficult.

本発明の非対称中空糸ガス分離膜は、実質的に前記テトラカルボン酸成分と前記ジアミン成分とに由来する一般式（１）の反復単位を有することによって、その作用効果を奏するが、本発明の課題を逸脱しない範囲において他のテトラカルボン酸成分とジアミン成分に由来するユニットが含まれていてもよい。他のテトラカルボン酸成分としては、例えばジフェニルエ−テルテトラカルボン酸類、ベンゾフェノンテトラカルボン酸類、ジフェニルスルホンテトラカルボン酸類、ナフタレンテトラカルボン酸類、ジフェニルメタンテトラカルボン酸類、ジフェニルプロパンテトラカルボン類等を挙げることができる。またその他のジアミン成分としては、例えばジアミノジフェニルメタン類、ジアミノジフェニルエーテル類、ジアミノジベンゾチオフェン類、ジアミノベンゾフェノン類、ビス（アミノフェニル）プロパン類、フェニレンジアミン類、ジアミノ安息香酸類等を挙げることができる。   The asymmetric hollow fiber gas separation membrane of the present invention has its effect by having the repeating unit of the general formula (1) substantially derived from the tetracarboxylic acid component and the diamine component. In the range which does not deviate from a subject, the unit derived from the other tetracarboxylic-acid component and diamine component may be contained. Examples of other tetracarboxylic acid components include diphenyl ether tetracarboxylic acids, benzophenone tetracarboxylic acids, diphenyl sulfone tetracarboxylic acids, naphthalene tetracarboxylic acids, diphenylmethane tetracarboxylic acids, diphenylpropane tetracarboxylic acids, and the like. . Examples of other diamine components include diaminodiphenylmethanes, diaminodiphenyl ethers, diaminodibenzothiophenes, diaminobenzophenones, bis (aminophenyl) propanes, phenylenediamines, and diaminobenzoic acids.

通常、非対称中空糸ガス分離膜は、テトラカルボン酸成分とジアミン成分との略等モルを有機極性溶媒中で重合イミド化して得られたポリイミドの溶液をド−プ液として使用し、これを中空糸形成用ノズルから押し出し中空糸状体を形成した後、凝固液中で凝固させて相転換を行わせる、いわゆる相転換法によって緻密層と多孔質層からなる非対称中空糸膜を形成し、次いで凝固液を除去して乾燥することによって製造する。
しかしながら、本発明の非対称中空糸ガス分離膜は、特許文献１及び特許文献２に記載された、テトラカルボン酸成分とジアミン成分とをランダムに重合イミド化して得られた一般式（１）の反復単位を有するポリイミドの溶液をド−プ液として相転換法に適用しても、得ることができない。 Usually, an asymmetric hollow fiber gas separation membrane uses a polyimide solution obtained by polymerization imidization of an approximately equimolar amount of a tetracarboxylic acid component and a diamine component in an organic polar solvent as a dope liquid. An asymmetric hollow fiber membrane composed of a dense layer and a porous layer is formed by a so-called phase change method in which a hollow fiber-like body is extruded from a yarn forming nozzle and then solidified in a coagulating liquid to cause phase change. Manufacture by removing the liquid and drying.
However, the asymmetric hollow fiber gas separation membrane of the present invention is a repeating of the general formula (1) described in Patent Document 1 and Patent Document 2 obtained by random polymerization imidization of a tetracarboxylic acid component and a diamine component. Even if a polyimide solution having units is applied as a dope solution to the phase conversion method, it cannot be obtained.

本発明の中空糸ガス分離膜は、全体の平均として前記一般式（１）の反復単位を有するポリイミドではあるが、テトラカルボン酸成分とジアミン成分の特定の成分が所定のブロック性を持つように重合イミド化して得られた多成分のポリイミドの溶液をドープ液として相転換法に適用することによって好適に製造することができる。   The hollow fiber gas separation membrane of the present invention is a polyimide having the repeating unit of the general formula (1) as an average of the whole, but the specific component of the tetracarboxylic acid component and the diamine component has a predetermined block property. A multicomponent polyimide solution obtained by polymerization imidization can be suitably produced by applying it as a dope solution to the phase conversion method.

以下、本発明で用いられる前記多成分のポリイミドの調製方法について説明する。
すなわち、本発明で用いられる全体の平均として前記一般式（１）の反復単位を有するポリイミドは、互いにモノマー組成が異なり、それぞれが所定の重合度を持ったポリイミドＡ成分及びポリイミドＢ成分を、混合した後、さらに重合イミド化することによって得られる。 Hereinafter, a method for preparing the multi-component polyimide used in the present invention will be described.
That is, the polyimide having the repeating unit of the general formula (1) as an average of the whole used in the present invention has a different monomer composition, and a polyimide A component and a polyimide B component each having a predetermined degree of polymerization are mixed. Then, it is obtained by further polymerizing imidization.

前記『ポリイミド成分』とは、ポリイミドの原料成分（未反応のテトラカルボン酸成分、未反応のジアミン成分）、及び／又は前記原料成分の重合イミド化反応物からなる。ここで、前記重合イミド化物は重合度が大きなポリマーのみを意味しない。ポリイミドの原料成分を重合イミド化したときに反応初期に生成するモノマーや重合度の低いオリゴマーなどを含む。すなわち、重合イミド化反応物は、モノマー（テトラカルボン酸成分とジアミン成分とが各１分子の計２分子でイミド化反応したもの）、及び／又はポリマー（テトラカルボン酸成分とジアミン成分とが計３分子以上でイミド化反応したもの）からなる。
本発明において、重合イミド化反応物の重合度はそこに含まれるポリイミドの繰返し単位数によるものとした。すなわち、モノマーの重合度は１であり、ポリマーの重合度は＞１である。一方、ポリイミドの原料成分の重合度は、繰返し単位を持たないので０．５と定義した。本発明の重合度は前記のように定義した重合度から算出される。 The “polyimide component” includes a raw material component of polyimide (unreacted tetracarboxylic acid component, unreacted diamine component) and / or a polymerization imidization reaction product of the raw material component. Here, the polymerized imidized product does not mean only a polymer having a high degree of polymerization. It includes a monomer generated at the initial stage of the reaction when the raw material component of polyimide is polymerized imidized, an oligomer having a low polymerization degree, and the like. That is, the polymerization imidization reaction product is composed of a monomer (a tetracarboxylic acid component and a diamine component imidized by a total of two molecules each) and / or a polymer (a tetracarboxylic acid component and a diamine component). And imidization reaction of 3 molecules or more).
In the present invention, the polymerization degree of the polymerization imidization reaction product is determined by the number of repeating units of the polyimide contained therein. That is, the degree of polymerization of the monomer is 1, and the degree of polymerization of the polymer is> 1. On the other hand, the polymerization degree of the raw material component of polyimide is defined as 0.5 because it has no repeating unit. The degree of polymerization of the present invention is calculated from the degree of polymerization defined as described above.

すなわち、ポリイミド成分Ａは、ポリイミドＡの原料成分（未反応のテトラカルボン酸成分、未反応のジアミン成分）及び／又は前記原料成分の重合イミド化反応物からなる。ポリイミド成分Ｂは、ポリイミドＢの原料成分（未反応のテトラカルボン酸成分、未反応のジアミン成分）及び／又は前記原料成分の重合イミド化反応物からなる。   That is, the polyimide component A is composed of a raw material component of polyimide A (unreacted tetracarboxylic acid component, unreacted diamine component) and / or a polymerization imidization reaction product of the raw material component. The polyimide component B is made of a raw material component of polyimide B (unreacted tetracarboxylic acid component, unreacted diamine component) and / or a polymerization imidization reaction product of the raw material component.

本発明において、ポリイミドＡ成分は、フッ素原子含有原料成分を含む。すなわち、前記式（３）のジフェニルヘキサフルオロプロパン構造を構成する２，２−ビス（３，４−ジカルボキシフェニル）ヘキサフルオロプロパン類成分を含む。一方、ポリイミドＢ成分は、基本的にはフッ素原子含有原料成分を含まない。なお、ポリイミドＢ成分が少量のフッ素原子含有原料成分を含む場合でも本発明の非対称中空糸ガス分離膜を得られることがあるが、その場合でも、全フッ素原子含有原料成分の大部分はポリイミドＡ成分に含まれ、ポリイミドＢ成分には全フッ素原子含有原料成分のうちの２０モル％以下特に１０モル％以下が含まれるだけである。そして、前記式（３）のジフェニルヘキサフルオロプロパン構造を構成する、フッ素原子含有原料成分である２，２−ビス（３，４−ジカルボキシフェニル）ヘキサフルオロプロパン類成分以外の原料成分、すなわち前記式（２）、式（４）、式（５）、式（６）、及び式（７）の構造を構成する原料成分であるテトラカルボン酸成分及びジアミン成分に関しては、特に限定はなく、ポリイミドＡ成分とポリイミドＢ成分のどちらに含まれても構わない。   In the present invention, the polyimide A component includes a fluorine atom-containing raw material component. That is, it contains a 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane component constituting the diphenylhexafluoropropane structure of the formula (3). On the other hand, the polyimide B component basically does not include a fluorine atom-containing raw material component. In addition, even when the polyimide B component contains a small amount of a fluorine atom-containing raw material component, the asymmetric hollow fiber gas separation membrane of the present invention may be obtained, but even in that case, most of the total fluorine atom-containing raw material component is polyimide A. It is contained in the component, and the polyimide B component contains only 20 mol% or less, particularly 10 mol% or less of the total fluorine atom-containing raw material component. And raw material components other than the 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane component which is a fluorine atom-containing raw material component constituting the diphenylhexafluoropropane structure of the formula (3), that is, the above-mentioned There are no particular limitations on the tetracarboxylic acid component and the diamine component, which are the raw material components constituting the structures of Formula (2), Formula (4), Formula (5), Formula (6), and Formula (7). It may be contained in either the A component or the polyimide B component.

前記ポリイミド成分Ａの数平均重合度をＮＡとし、前記ポリイミド成分Ｂの数平均重合度をＮＢとすると、本発明の非対称中空糸ガス分離膜は、次の工程１〜工程３によって好適に製造することができる。
（工程１）ポリイミド成分Ａとポリイミド成分Ｂとを、ＮＡとＮＢとが下記数式１を満たす重合度の組合せで混合して多成分ポリイミドの混合溶液を調製する。 The number average degree of polymerization of the polyimide component A and N A, the number average polymerization degree of the polyimide component B and N B, asymmetric hollow fiber gas separation membrane of the present invention, preferably by the following Steps 1 to 3 Can be manufactured.
(Step 1) A polyimide component A and a polyimide component B are mixed with a combination of polymerization degrees in which N A and N B satisfy the following formula 1 to prepare a mixed solution of multi-component polyimide.

Figure 0005358903
（工程２）前記多成分ポリイミドの混合溶液をさらに重合イミド化反応させる。
（工程３）前記多成分ポリイミドの混合溶液を用いて相転換法によって非対称中空糸膜を形成する。
Figure 0005358903
 (Step 2) The mixed solution of the multi-component polyimide is further subjected to a polymerization imidization reaction.
(Step 3) An asymmetric hollow fiber membrane is formed by a phase conversion method using the mixed solution of the multi-component polyimide.

工程１は、多成分ポリイミドの混合溶液が得ることができれば具体的方法は特に限定されない。ポリイミドＡの原料成分とポリイミドＢの原料成分とをそれぞれ独立に必要に応じて重合イミド化反応によって調製した後でそれらを均一になるように混合して多成分ポリイミドの混合溶液を得ることもできる。また、工程１の多成分ポリイミドの混合溶液が、いずれか一方のポリイミド成分が原料成分（未反応のテトラカルボン酸成分、未反応のジアミン成分）の場合には、一方のポリイミド成分の原料成分を所定の数平均重合度になるように重合イミド化反応した溶液を調製し、次いで前記溶液に他方のポリイミド成分である未反応のテトラカルボン酸成分とジアミン成分を加えても構わない。特にポリイミドＢ成分をより高分子量化することが非対称中空糸膜の機械的強度を向上させるうえで好適なので、工程１で先ずポリイミドＢ成分をなす原料成分を極性溶媒中で重合イミド化反応して適当な重合度のポリイミドＢ成分となし、これにポリイミドＡ成分をなす原料成分を添加して多成分ポリイミドの混合溶液を調製する方法が好都合である。   Step 1 is not particularly limited as long as a mixed solution of multi-component polyimide can be obtained. A raw material component of polyimide A and a raw material component of polyimide B can be independently prepared by a polymerization imidization reaction as necessary, and then mixed uniformly to obtain a mixed solution of multi-component polyimide. . In addition, when the mixed solution of the multi-component polyimide in Step 1 is a raw material component (unreacted tetracarboxylic acid component, unreacted diamine component), the raw material component of one polyimide component is A solution obtained by polymerization imidization reaction so as to have a predetermined number average degree of polymerization may be prepared, and then an unreacted tetracarboxylic acid component and a diamine component which are other polyimide components may be added to the solution. In particular, since higher molecular weight of the polyimide B component is suitable for improving the mechanical strength of the asymmetric hollow fiber membrane, first, in Step 1, the raw material component forming the polyimide B component is subjected to a polymerization imidization reaction in a polar solvent. A method of preparing a mixed solution of multi-component polyimide by adding a polyimide B component having an appropriate degree of polymerization and adding a raw material component forming the polyimide A component thereto is convenient.

ここで、ポリイミドを得る重合イミド化反応について説明する。重合イミド化反応は、極性溶媒中テトラカルボン酸成分とジアミン成分とを、所定の組成比で、１４０℃以上好ましくは１６０℃以上且つ使用する溶媒の沸点以下の温度範囲で、ポリアミド酸を生成すると共に脱水閉環反応を行わせてイミド化することによって好適に行われる。テトラカルボン酸成分とジアミン成分の重合イミド化の速度が低温においても大きく所定の重合度を達成できる場合は１４０℃以下の温度でもよい。この反応はポリアミド酸の脱水閉環反応に伴う水の発生が無くなるまで、好適にはポリアミド酸の脱水閉環反応に伴う水の発生が見かけ上なくなるまでの時間の１．２倍好ましくは２倍以上の反応時間をかけて行うことが好適である。水の発生が無くなることは、反応系にトラップを取り付け、前記トラップに新たな水の凝縮が生じなくなることを目視観察して確認できる。この方法によって所定の重合度を持ったポリイミドが得られる。アミド酸結合が残ると交換反応によってポリイミドのブロック性が損なわれることがあるので、重合イミド化反応では少なくともイミド化率は５０％以上であることが好ましく、実質的にイミド化を完了させることがより好ましい。   Here, the polymerization imidation reaction for obtaining polyimide will be described. The polymerization imidation reaction generates a polyamic acid in a polar solvent in a temperature range of 140 ° C. or more, preferably 160 ° C. or more and the boiling point of the solvent to be used, with a predetermined composition ratio of a tetracarboxylic acid component and a diamine component. At the same time, it is preferably carried out by imidizing by carrying out a dehydration ring closure reaction. When the polymerization imidization rate of the tetracarboxylic acid component and the diamine component is large even at a low temperature and a predetermined degree of polymerization can be achieved, the temperature may be 140 ° C. or lower. This reaction is preferably 1.2 times, preferably 2 times or more of the time until water generation associated with the polyamic acid dehydration ring-closing reaction disappears, preferably until the water generation associated with the polyamic acid dehydration ring-closing reaction apparently disappears. It is preferable to carry out the reaction over a long time. The disappearance of water generation can be confirmed by attaching a trap to the reaction system and visually observing that no new water is condensed in the trap. By this method, a polyimide having a predetermined degree of polymerization can be obtained. If the amic acid bond remains, the blocking property of the polyimide may be impaired by the exchange reaction. Therefore, it is preferable that at least the imidization rate is 50% or more in the polymerization imidization reaction, and the imidization can be substantially completed. More preferred.

重合イミド化反応において、テトラカルボン酸成分とジアミン成分との組成比を近づけて反応すると比較的高分子量（数平均重合度が大きい）のポリイミドを合成することができる。最初に比較的高分子量のポリイミドを調製する場合には、テトラカルボン酸成分１モル部に対してジアミン成分が０．９５〜０．９９５モル部又は１．００５〜１．０５モル部、特に０．９８〜０．９９５モル部又は１．００５〜１．０２モル部の範囲の組成比で反応して、比較的高分子量のポリイミド成分を調製するのが好ましい。
一方、テトラカルボン酸成分１モル部に対してジアミン成分が０．９８モル部以下又は１．０２モル部以上の組成比で反応することにより、比較的低分子量（数平均重合度が小さい）のポリイミド成分を調製することもできる。 In the polymerization imidization reaction, a polyimide having a relatively high molecular weight (high number average degree of polymerization) can be synthesized by reacting with the composition ratio of the tetracarboxylic acid component and the diamine component close to each other. When a relatively high molecular weight polyimide is first prepared, the diamine component is 0.95 to 0.995 mol part or 1.005 to 1.05 mol part, particularly 0 to 1 mol part of the tetracarboxylic acid component. It is preferable to react at a composition ratio in the range of .98 to 0.995 mole part or 1.005 to 1.02 mole part to prepare a relatively high molecular weight polyimide component.
On the other hand, the diamine component reacts at a composition ratio of 0.98 mol part or less or 1.02 mol part or more with respect to 1 mol part of the tetracarboxylic acid component, so that a relatively low molecular weight (number average degree of polymerization is small). A polyimide component can also be prepared.

工程１で得られる多成分ポリイミドの混合溶液は、テトラカルボン酸成分の総モル数に対するジアミン成分の総モル数の組成比（（ジアミン成分の総モル数）／（テトラカルボン酸成分の総モル数））が０．９５〜０．９９又は１．０１〜１．０５モル部、より好ましくは０．９６〜０．９９又は１．０１５〜１．０４モル部の範囲内となるようにすることが、工程２の結果得られる多成分ポリイミドの混合溶液の重合度や溶液粘度が好適になるので好ましい。   The mixed solution of the multi-component polyimide obtained in step 1 is a composition ratio of the total number of moles of the diamine component to the total number of moles of the tetracarboxylic acid component ((total number of moles of diamine component) / (total number of moles of tetracarboxylic acid component). )) Within a range of 0.95 to 0.99 or 1.01 to 1.05 mole part, more preferably 0.96 to 0.99 or 1.015 to 1.04 mole part. However, the polymerization degree and the solution viscosity of the mixed solution of the multi-component polyimide obtained as a result of Step 2 are preferable.

前記数式１のＮＡとＮＢの組合せの範囲を図１の斜線領域で示した。なお、前記図１中のＡ領域の組合せでは機械的強度が向上した非対称中空糸ガス分離膜を得るのが難しく、Ｂ領域の組合せでは、ガス分離特性が良好な非対称中空糸ガス分離膜を得ることが難しくなる。 The scope of the combination of N A and N B of Equation 1 shown by the shaded area of FIG. In addition, it is difficult to obtain an asymmetric hollow fiber gas separation membrane with improved mechanical strength with the combination of the A region in FIG. 1, and an asymmetric hollow fiber gas separation membrane with good gas separation characteristics is obtained with the combination of the B region. It becomes difficult.

工程２は、工程１で得られたポリイミドＡ成分とポリイミドＢ成分とからなる多成分ポリイミドの混合溶液をさらに重合イミド化反応させて、少なくともポリイミド成分Ａからなる重合体と、ポリイミド成分Ｂからなる重合体に加えて、ポリイミド成分Ａとポリイミド成分Ｂとが互いの末端で結合したブロックを有するジ又はマルチブロック共重合体を含有し且つ適当な重合度を持った多成分ポリイミドの混合液を得る工程である。ここで、ジブロック共重合体とは、ポリイミド成分Ａからなるブロックとポリイミド成分Ｂからなるブロックの各１個が互いの末端で結合した共重合体のことであり、マルチブロック共重合体は前記ジブロック共重合体の末端に前記２種のブロックが更に１個以上結合した共重合体のことである。ジ又はマルチブロック共重合体には、ポリイミド成分Ａからなるブロックが連続して結合した部分やポリイミド成分Ｂからなるブロックが連続して結合した部分も存在し得る。   Step 2 further comprises a polymerized imidization reaction of the mixed solution of the multicomponent polyimide composed of the polyimide A component and the polyimide B component obtained in step 1 to form a polymer composed of at least the polyimide component A and the polyimide component B. In addition to the polymer, a di- or multi-block copolymer having a block in which polyimide component A and polyimide component B are bonded to each other end is obtained, and a mixed solution of multi-component polyimide having an appropriate degree of polymerization is obtained. It is a process. Here, the diblock copolymer is a copolymer in which each one of the block composed of the polyimide component A and the block composed of the polyimide component B is bonded to each other terminal, and the multiblock copolymer is the above-mentioned It is a copolymer in which one or more of the two types of blocks are further bonded to the end of the diblock copolymer. In the di- or multi-block copolymer, there may be a portion in which blocks composed of the polyimide component A are continuously bonded and a portion in which blocks composed of the polyimide component B are continuously bonded.

本発明の工程２の重合イミド化反応は、ポリイミド成分Ａとポリイミド成分Ｂとが互いの末端で結合したブロックを有するジ又はマルチブロック共重合体を生成させることができれば特に限定されるものではない。通常は多成分ポリイミド混合溶液の数平均分子量が好ましくは２倍以上より好ましくは５倍以上になる程度まで重合イミド化反応を行えば、ジ又はマルチブロック共重合体を好適に生成させることができる。工程２の重合イミド化反応によって得られる多成分ポリイミドの混合溶液の数平均重合度は２０〜１０００好ましくは２０〜５００より好ましくは３０〜２００が好適である。数平均重合度が低過ぎると、混合溶液の溶液粘度が低すぎて工程３の製膜が困難になり、得られる非対称膜の機械的強度が低下するので好ましくない。数平均重合度が高過ぎると、溶液粘度が高くなり過ぎて工程３の製膜が困難になるので好ましくない。工程２で得られる多成分ポリイミドの混合溶液の溶液粘度（回転粘度）は、相転換法において非対称中空糸膜を形成するときに、溶液を中空糸形状にし更にその形状を安定化するために要求される特性である。
本発明においては、多成分ポリイミドの混合溶液の溶液粘度を、１００℃において２０〜１７０００ポイズ、好ましくは１００〜１５０００ポイズ、特に２００〜１００００に調製するのが好適である。このような溶液粘度のポリイミド溶液であれば、非対称中空糸膜を製造するときの紡糸過程においてポリイミド溶液をノズルから吐出する際、吐出後の中空糸形状を安定に得ることができるので好適である。溶液粘度が２０ポイズより低いか、あるいは１７０００ポイズより高いと中空糸形状を安定に得ることが困難になる。
なお、好適な多成分ポリイミドの混合溶液の数平均重合度及び好適な溶液粘度は、工程１で得られる多成分ポリイミドの混合溶液のテトラカルボン酸成分の総モル数に対するジアミン成分の総モル数の組成比（（ジアミン成分の総モル数）／（テトラカルボン酸成分の総モル数））を０．９５〜０．９９又は１．０１〜１．０５モル部、より好ましくは０．９６〜０．９９又は１．０１５〜１．０４モル部の範囲内にして、工程２の重合イミド化反応によって容易に得られる。 The polymerization imidation reaction in step 2 of the present invention is not particularly limited as long as a di- or multi-block copolymer having a block in which polyimide component A and polyimide component B are bonded to each other can be produced. . Usually, a di- or multi-block copolymer can be suitably formed by carrying out the polymerization imidation reaction until the number average molecular weight of the multi-component polyimide mixed solution is preferably 2 times or more, more preferably 5 times or more. . The number average degree of polymerization of the mixed solution of the multicomponent polyimide obtained by the polymerization imidation reaction in step 2 is 20 to 1000, preferably 20 to 500, more preferably 30 to 200. If the number average degree of polymerization is too low, the solution viscosity of the mixed solution is too low, making film formation in Step 3 difficult, and the mechanical strength of the resulting asymmetric film is lowered, which is not preferable. If the number average degree of polymerization is too high, the solution viscosity becomes too high and film formation in Step 3 becomes difficult, which is not preferable. The solution viscosity (rotational viscosity) of the mixed solution of multi-component polyimide obtained in Step 2 is required to make the solution into a hollow fiber shape and to stabilize the shape when forming an asymmetric hollow fiber membrane in the phase change method. Is a characteristic.
In the present invention, the solution viscosity of the mixed solution of the multi-component polyimide is preferably adjusted to 20 to 17000 poise, preferably 100 to 15000 poise, particularly 200 to 10,000 at 100 ° C. A polyimide solution having such a solution viscosity is preferable because a hollow fiber shape after ejection can be stably obtained when the polyimide solution is ejected from a nozzle in the spinning process when producing an asymmetric hollow fiber membrane. . If the solution viscosity is lower than 20 poise or higher than 17000 poise, it is difficult to stably obtain a hollow fiber shape.
The number average polymerization degree and the suitable solution viscosity of the suitable mixed solution of the multicomponent polyimide are the total number of moles of the diamine component relative to the total number of tetracarboxylic acid components of the mixed solution of the multicomponent polyimide obtained in Step 1. The composition ratio ((total number of moles of diamine component) / (total number of moles of tetracarboxylic acid component)) is 0.95 to 0.99 or 1.01 to 1.05 mole part, more preferably 0.96 to 0. It can be easily obtained by the polymerization imidation reaction in Step 2 in the range of .99 or 1.015 to 1.04 mol part.

工程１及び工程２の多成分ポリイミドの混合溶液のポリマー濃度は、５〜４０重量％好ましくは８〜３０重量％特に９〜２５重量％である。また、前記工程１及び工程２の多成分ポリイミドの混合溶液では、多成分ポリイミドを均一に溶解する極性有機溶媒が好適に用いられる。前記有機極性溶媒としては、その融点が２００℃以下、好ましくは１５０℃以下のもの、例えばフェノ−ル、クレゾ−ル、キシレノ−ル、ベンゼン環に２個の水酸基を有するカテコ−ル、レゾルシンの如きカテコ−ル類、３−クロロフェノ−ル、４−クロロフェノ−ル、３−ブロモフェノ−ル、４−ブロモフェノ−ル、２−クロロ−５−ヒドロキシトルエンの如きハロゲン化フェノ−ル類、Ｎ−メチル−２−ピロリドン、Ｎ，Ｎ−ジメチルホルムアミド、Ｎ，Ｎ−ジエチルホルムアミド、Ｎ，Ｎ−ジメチルアセトアミド、Ｎ，Ｎ−ジエチルアセトアミドの如きアミド類や、これらの混合溶媒が好適である。   The polymer concentration of the mixed solution of the multi-component polyimide in step 1 and step 2 is 5 to 40% by weight, preferably 8 to 30% by weight, particularly 9 to 25% by weight. Moreover, in the mixed solution of the multicomponent polyimide of the said process 1 and the process 2, the polar organic solvent which melt | dissolves a multicomponent polyimide uniformly is used suitably. Examples of the organic polar solvent include those having a melting point of 200 ° C. or lower, preferably 150 ° C. or lower, such as phenol, cresol, xylenol, catechol having two hydroxyl groups in the benzene ring, and resorcinol. Catechols such as, 3-chlorophenol, 4-chlorophenol, 3-bromophenol, 4-bromophenol, halogenated phenols such as 2-chloro-5-hydroxytoluene, N-methyl Preferred are amides such as 2-pyrrolidone, N, N-dimethylformamide, N, N-diethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide, and mixed solvents thereof.

工程３は、前記工程２で得られた多成分ポリイミドの混合溶液を用いて相転換法によって非対称中空糸ガス分離膜を形成する。相転換法は、ポリマー溶液を凝固液と接触させて相転換させながら膜を形成する公知の方法であり、本発明ではいわゆる乾湿式法が好適に採用される。乾湿式法は、膜形状にしたポリマー溶液の表面の溶媒を蒸発させて薄い緻密層を形成し、次いで凝固液（ポリマー溶液の溶媒とは相溶し、ポリマーは不溶な溶剤）に浸漬し、その際生じる相分離現象を利用して微細孔を形成して多孔質層を形成させる方法であり、Ｌｏｅｂらが提案（例えば、米国特許３１３３１３２号）したものである。   In step 3, an asymmetric hollow fiber gas separation membrane is formed by a phase conversion method using the mixed solution of the multicomponent polyimide obtained in step 2 above. The phase change method is a known method for forming a film while bringing a polymer solution into contact with a coagulation liquid to cause phase change. In the present invention, a so-called dry and wet method is suitably employed. In the dry-wet method, the solvent on the surface of the polymer solution in the form of a film is evaporated to form a thin dense layer, and then immersed in a coagulation liquid (solvent that is compatible with the solvent of the polymer solution and the polymer is insoluble), This is a method of forming a microporous layer by utilizing the phase separation phenomenon that occurs at that time to form a porous layer, and was proposed by Loeb et al. (For example, US Pat. No. 3,133,132).

乾湿式紡糸法は、紡糸ノズルからポリマー溶液を吐出して中空糸形状とし、吐出直後に空気又は窒素ガス雰囲気中を通した後、ポリマー成分を実質的には溶解せず且つポリマー混合液の溶媒とは相溶性を有する凝固液に浸漬して相転換させて非対称構造を形成し、その後乾燥し、更に必要に応じて加熱処理して分離膜を製造する方法である。
ノズルから吐出させる多成分ポリイミドの混合溶液の溶液粘度は、前述のとおり、吐出温度（例えば１００℃）で２０〜１７０００ポイズ、好ましくは１００〜１５０００ポイズ、特に２００〜１００００ポイズとなるようなポリイミド溶液が中空糸状などの吐出後の形状を安定に得ることができるので好ましい。凝固液への浸漬は、一次凝固液に浸漬して中空糸状などの膜の形状が保持できる程度に凝固した後、案内ロールに巻き取られ、次いで二次凝固液に浸漬して膜全体を十分に凝固させることが好ましい。凝固した膜の乾燥は炭化水素などの溶媒を用いて凝固液と置換した後乾燥する方法が効率的である。加熱処理は用いられている多成分のポリイミドの各成分ポリマーの軟化点又は二次転移点よりも低い温度で実施されることが好ましい。 In the dry-wet spinning method, a polymer solution is discharged from a spinning nozzle to form a hollow fiber, and after passing through an air or nitrogen gas atmosphere immediately after discharge, the polymer component is not substantially dissolved and the solvent of the polymer mixed solution Is a method for producing a separation membrane by immersing in a compatible coagulating liquid to cause phase transformation to form an asymmetric structure, followed by drying and further heat treatment as necessary.
As described above, the solution viscosity of the mixed solution of the multi-component polyimide discharged from the nozzle is 20 to 17000 poise, preferably 100 to 15000 poise, particularly 200 to 10,000 poise at the discharge temperature (for example, 100 ° C.). Is preferable because a shape after discharge such as a hollow fiber shape can be stably obtained. For immersion in the coagulation liquid, the film is immersed in the primary coagulation liquid and solidified to such an extent that the shape of the membrane such as a hollow fiber can be maintained, wound on a guide roll, and then immersed in the secondary coagulation liquid to fully saturate the entire film. It is preferable to solidify. For drying the coagulated film, a method of drying after replacing the coagulating liquid with a solvent such as hydrocarbon is effective. The heat treatment is preferably carried out at a temperature lower than the softening point or secondary transition point of each component polymer of the multicomponent polyimide used.

本願発明の非対称中空糸ガス分離膜は、全体の平均として前記一般式（１）の反復単位を有するポリイミドからなり、前述の製造方法によって得られ、主としてガス分離性能を担う極めて薄い緻密層（好ましくは厚さが０．００１〜５μｍ）とその緻密層を支える比較的厚い多孔質層（好ましくは厚さが１０〜２０００μｍ）とからなる非対称構造を有する中空糸膜であり、その内径は好適には１０〜３０００μｍでその外径は好適には３０〜７０００μｍ程度である。そして、中空糸膜としての引張り破断強度が３ｋｇｆ／ｍｍ２以上好ましくは４ｋｇｆ／ｍｍ２以上であり、特に中空糸膜としての引張り破断伸度が１５％以上好ましくは２０％以上の機械的強度を有する。 The asymmetric hollow fiber gas separation membrane of the present invention is made of polyimide having the repeating unit of the general formula (1) as an average of the whole, and is obtained by the above-described production method, and is an extremely thin dense layer mainly responsible for gas separation performance (preferably Is a hollow fiber membrane having an asymmetric structure composed of 0.001 to 5 μm in thickness) and a relatively thick porous layer (preferably 10 to 2000 μm in thickness) that supports the dense layer. Is 10 to 3000 μm and its outer diameter is preferably about 30 to 7000 μm. The tensile strength at break as a hollow fiber membrane is 3 kgf / mm 2 or more, preferably 4 kgf / mm 2 or more, and the tensile strength at break as a hollow fiber membrane is 15% or more, preferably 20% or more. Have.

さらに、本発明の非対称中空糸ガス分離膜は、５０℃で測定した酸素ガスの透過速度（Ｐ’Ｏ２）が４．０×１０−５ｃｍ３（ＳＴＰ）／ｃｍ２・ｓｅｃ・ｃｍＨｇ以上好ましくは５．０×１０−５ｃｍ３（ＳＴＰ）／ｃｍ２・ｓｅｃ・ｃｍＨｇ以上、且つ窒素ガスの透過速度に対する酸素ガスの透過速度の比（Ｐ’Ｏ２／Ｐ’Ｎ２）が４以上好ましくは４．５以上である。 Further, the asymmetric hollow fiber gas separation membrane of the present invention preferably has an oxygen gas permeation rate ( P′O2 ) measured at 50 ° C. of 4.0 × 10 −5 cm 3 (STP) / cm 2 · sec · cmHg or more. is 5.0 × 10 -5 cm 3 (STP ) / cm 2 · sec · cmHg or more and the ratio of permeation rates of oxygen gas to permeation rate of nitrogen gas (P 'O2 / P' N2 ) is 4 or more, preferably 4.5 or more.

以上のとおり、本発明の非対称中空糸ガス分離膜は、優れたガス分離性能と共に改良された機械的強度を有する。このような機械的強度を持った中空糸膜、特に引張り破断伸度が１５％以上の中空糸膜は、容易に破損や破断することなく取扱うことができるので、工業的にモジュール化（ガス分離膜モジュールへの組立て及び加工）をすることができる。更に、このような機械的強度を持った中空糸膜を用いたガス分離膜モジュールは、優れた耐圧性や耐久性を持つので特に有用である。一方、引張り破断伸度が１５％以下では、ガス分離膜モジュールへの組立て及び加工時に中空糸膜が破損や破断を起こし易いので工業的に分離膜モジュールへ組立て及び加工することが困難である。更に、分離膜モジュールとしても、使用時の耐圧性が低くなり用途や使用条件が限定される。特に、分離膜モジュール内の中空糸膜は、供給されて中空糸膜の内側や外側を流れて排出されるガスの流量、流速、圧力、温度、及び、それらの変動によって、連続的又は断続的に変形応力を受けるので、引張り破断伸度が１５％以下では、破損や破断が発生し易くなり実用上の問題を生じ易い。
本発明の非対称中空糸ガス分離膜は、ガス分離性能特に酸素ガスと窒素ガスとの分離性能に優れるが、酸素ガスと窒素ガスとを分離する場合（例えば空気から富化窒素ガスを分離する場合）には、高圧の混合ガス（空気）をガス分離膜モジュールへ供給するから、実用上中空糸膜の機械的強度は極めて重要な特性である。 As described above, the asymmetric hollow fiber gas separation membrane of the present invention has improved mechanical strength along with excellent gas separation performance. Hollow fiber membranes with such mechanical strength, especially those with a tensile elongation at break of 15% or more, can be handled easily without breakage or breakage. Assembly into a membrane module and processing). Furthermore, a gas separation membrane module using such a hollow fiber membrane having mechanical strength is particularly useful because it has excellent pressure resistance and durability. On the other hand, when the tensile elongation at break is 15% or less, the hollow fiber membrane tends to be damaged or broken during assembly and processing into the gas separation membrane module, so that it is difficult to assemble and process the separation membrane module industrially. Furthermore, as a separation membrane module, the pressure resistance at the time of use becomes low, and the use and use conditions are limited. In particular, the hollow fiber membrane in the separation membrane module is continuously or intermittently depending on the flow rate, flow velocity, pressure, temperature, and fluctuations of the gas supplied and flowing inside and outside the hollow fiber membrane. Therefore, if the tensile elongation at break is 15% or less, breakage or breakage is likely to occur, and practical problems are likely to occur.
The asymmetric hollow fiber gas separation membrane of the present invention is excellent in gas separation performance, particularly separation performance of oxygen gas and nitrogen gas, but when separating oxygen gas and nitrogen gas (for example, separating enriched nitrogen gas from air) ), A high-pressure mixed gas (air) is supplied to the gas separation membrane module, so that the mechanical strength of the hollow fiber membrane is an extremely important characteristic for practical use.

従って、本発明の非対称中空糸ガス分離膜は、酸素ガスと窒素ガスとを分離する際に極めて好適に用いることができる。すなわち、本発明の非対称中空糸ガス分離膜の供給側に、酸素ガスと窒素ガスを含む混合ガスを接触させ、前記非対称中空糸ガス分離膜の透過側へ酸素ガスを選択的に透過させることによって、酸素ガスと窒素ガスとを含む混合ガスから、酸素ガスが富化した混合ガスと窒素ガスが富化した混合ガスとを、極めて好適に分離回収することができる。さらに、本発明の非対称中空糸ガス分離膜は、機械的強度が優れるので、非対称中空糸ガス分離膜の内側（孔側）を供給側とし、非対称中空糸ガス分離膜の外側を透過側として、前記の酸素ガスと窒素ガスとを含む混合ガスから、酸素ガスが富化した混合ガスと窒素ガスが富化した混合ガスとを、極めて好適に分離回収することができる。この方法は、非対称中空糸ガス分離膜の外側を供給側とし、非対称中空糸ガス分離膜の内側を透過側とした時と比較して、効率的な分離回収を行える場合が多い。
なお、この酸素ガスと窒素ガスとを分離する時の、温度や圧力などの分離条件には特に限定はなく、通常のガス分離膜で採用されている分離条件が採用されるが、好ましくは温度が−２０℃〜８０℃で圧力を０．１ＭＰａＧ〜１．６ＭＰａＧに加圧した混合ガスをガス分離膜モジュールの混合ガス供給口から供給して好適に行うことができる。 Therefore, the asymmetric hollow fiber gas separation membrane of the present invention can be used very suitably when separating oxygen gas and nitrogen gas. That is, by bringing a mixed gas containing oxygen gas and nitrogen gas into contact with the supply side of the asymmetric hollow fiber gas separation membrane of the present invention and selectively allowing oxygen gas to permeate through the permeation side of the asymmetric hollow fiber gas separation membrane. From the mixed gas containing oxygen gas and nitrogen gas, the mixed gas enriched with oxygen gas and the mixed gas enriched with nitrogen gas can be separated and recovered very suitably. Furthermore, since the asymmetric hollow fiber gas separation membrane of the present invention is excellent in mechanical strength, the inside (hole side) of the asymmetric hollow fiber gas separation membrane is the supply side, and the outside of the asymmetric hollow fiber gas separation membrane is the permeation side, From the mixed gas containing oxygen gas and nitrogen gas, the mixed gas enriched with oxygen gas and the mixed gas enriched with nitrogen gas can be separated and recovered very suitably. In many cases, this method can perform efficient separation and recovery as compared with the case where the outside of the asymmetric hollow fiber gas separation membrane is the supply side and the inside of the asymmetric hollow fiber gas separation membrane is the permeation side.
There are no particular limitations on the separation conditions such as temperature and pressure when separating the oxygen gas and nitrogen gas, and the separation conditions employed in ordinary gas separation membranes are employed. However, it can be suitably performed by supplying a mixed gas whose pressure is increased from −20 ° C. to 80 ° C. to a pressure of 0.1 MPaG to 1.6 MPaG from the mixed gas supply port of the gas separation membrane module.

本発明の非対称中空糸ガス分離膜は、機械的強度が優れるので、モジュール化して好適に用いることができる。中空糸ガス分離膜は、中空糸膜であるためにモジュール当たりの膜面積を広くできるし、高圧の混合ガスを供給してガスを分離できるので、高効率のガス分離が可能になる。通常のガス分離膜モジュールは、例えば、適当な長さの中空糸膜１００〜１０００００本程度を束ね、その中空糸束の少なくとも一方の端部を、各中空糸膜が開口状態を保持した状態になるようにして、熱硬化性樹脂などからなる管板で包埋して固着し、得られた少なくとも中空糸束と管板などからなる中空糸膜エレメントを、少なくとも混合ガス供給口と透過ガス排出口と非透過ガス排出口とを備える容器内に、中空糸膜の内側に通じる空間と中空糸膜の外側へ通じる空間とが隔絶するように収納し取り付けることによって得られる。このようなガス分離膜モジュールでは、混合ガスが混合ガス供給口から中空糸膜の内側（孔側）あるいは外側に接する空間へ供給され、中空糸膜に接して流れる間に混合ガス中の特定成分が選択的に膜を透過し、透過ガスが透過ガス排出口から、膜を透過しなかった非透過ガスが非透過ガス排出口からそれぞれ排出されることによって、好適にガス分離が行われる。   Since the asymmetric hollow fiber gas separation membrane of the present invention is excellent in mechanical strength, it can be suitably used in a modular form. Since the hollow fiber gas separation membrane is a hollow fiber membrane, the membrane area per module can be widened, and the gas can be separated by supplying a high-pressure mixed gas, thereby enabling highly efficient gas separation. A normal gas separation membrane module, for example, bundles about 100 to 100,000 hollow fiber membranes of appropriate length, and at least one end of the hollow fiber bundle is in a state in which each hollow fiber membrane maintains an open state. In this way, the hollow fiber membrane element consisting of at least a hollow fiber bundle and the tube sheet is embedded and fixed with a tube sheet made of a thermosetting resin or the like, and at least the mixed gas supply port and the permeated gas exhaust. It is obtained by storing and mounting in a container having an outlet and a non-permeate gas outlet so that the space leading to the inside of the hollow fiber membrane and the space leading to the outside of the hollow fiber membrane are isolated. In such a gas separation membrane module, a mixed gas is supplied from a mixed gas supply port to a space in contact with the inside (hole side) or outside of the hollow fiber membrane, and a specific component in the mixed gas while flowing in contact with the hollow fiber membrane. Selectively permeate the membrane, and the permeate gas is discharged from the permeate gas discharge port, and the non-permeate gas that has not permeated the membrane is discharged from the non-permeate gas discharge port, whereby gas separation is suitably performed.

図２に、本発明の非対称中空糸ガス分離膜を用いたガス分離膜モジュール、及びその使用方法の一例について、概略図で示した。   FIG. 2 is a schematic diagram showing an example of a gas separation membrane module using the asymmetric hollow fiber gas separation membrane of the present invention and a method for using the same.

本発明での各種測定方法について説明する。
（回転粘度の測定法）
ポリイミド溶液の溶液粘度は、回転粘度計（ローターのずり速度１．７５ｓｅｃ−１）を用い温度１００℃で測定した。 Various measurement methods in the present invention will be described.
(Method for measuring rotational viscosity)
The solution viscosity of the polyimide solution was measured at a temperature of 100 ° C. using a rotational viscometer (shear rate of rotor: 1.75 sec −1 ).

（重合度の測定）
本発明において、重合度は、例えばゲルパーミエーションクロマトグラフィ（ＧＰＣ）測定または赤外分光法などによるイミド化率の測定によってあらかじめ数平均重合度と溶液粘度との対応を調べておき、反応溶液の溶液粘度の測定によって数平均重合度を知ることができる。なお、イミド化率が９０％以上のものが対象の場合には、ＧＰＣ測定法によって求め、イミド化率が９０％未満の場合には、赤外分光法によるイミド化率測定法から求めた。
本発明においてＧＰＣ測定は以下のようにして行った。日本分光工業株式会社製８００シリーズＨＰＬＣシステムを用い、カラムはＳｈｏｄｅｘ ＫＤ−８０６Ｍを1本、カラム部温度は４０℃、検出器は未知試料用としてインテリジェント紫外可視分光検出器（吸収波長３５０ｎｍ）、標準物質用として示差屈折計（標準物質はポリエチレングリコール）を使用した。溶媒は塩化リチウム及びリン酸を各々０．０５モル／Ｌ含むＮ−メチル−２−ピロリドン溶液を使用し、溶媒の流速は０．５ｍＬ／分、サンプルの濃度は約０．１％とした。データの取り込み及びデータ処理はＪＡＳＣＯ−ＪＭＢＳ／ＢＯＲＷＩＮを用い行なった。データの取り込みは２回／秒行ない、試料のクロマトグラムを得た。一方、標準物質として分子量８２，２５０、２８，７００、６，４５０、１，９００のポリエチレングリコールを使用し、これらのクロマトグラムからピークを検出し、保持時間と分子量の関係を示す校正曲線を得た。未知試料の分子量解析は、校正曲線から各保持時間における分子量Ｍｉを各々求め、また、各保持時間におけるクロマトグラムの高さｈｉの合計に対する分率Ｗｉ＝ｈｉ／Σｈｉを求め、それらをもとに数平均分子量Ｍｎは１／｛Σ（Ｗｉ／Ｍｉ）｝から、重量平均分子量ＭｗはΣ（Ｗｉ・Ｍｉ）から求めた。
数平均重合度Ｎは、重合時の仕込み割合に応じて平均化したモノマー単位分子量＜ｍ＞で数平均分子量Ｍｎを除して求めた。 (Measurement of degree of polymerization)
In the present invention, the degree of polymerization is determined by checking the correspondence between the number average degree of polymerization and the solution viscosity in advance by, for example, gel permeation chromatography (GPC) measurement or measurement of imidization rate by infrared spectroscopy. The number average degree of polymerization can be known by measuring the viscosity. In addition, when the thing of 90% or more of imidation rate is object, it calculated | required by the GPC measuring method, and when the imidation rate was less than 90%, it calculated | required from the imidation rate measuring method by infrared spectroscopy.
In the present invention, GPC measurement was performed as follows. Using 800 series HPLC system manufactured by JASCO Corporation, the column is one Shodex KD-806M, the column temperature is 40 ° C, the detector is an intelligent UV-visible spectroscopic detector (absorption wavelength 350nm) for unknown samples, standard A differential refractometer (standard material is polyethylene glycol) was used for the substance. The solvent used was an N-methyl-2-pyrrolidone solution containing 0.05 mol / L of lithium chloride and phosphoric acid, the solvent flow rate was 0.5 mL / min, and the sample concentration was about 0.1%. Data acquisition and data processing were performed using JASCO-JMBS / BORWIN. Data acquisition was performed twice / second to obtain a chromatogram of the sample. On the other hand, polyethylene glycols having molecular weights of 82, 250, 28, 700, 6, 450, and 1,900 are used as standard substances, and peaks are detected from these chromatograms to obtain a calibration curve indicating the relationship between retention time and molecular weight. It was. Molecular weight analysis of an unknown sample, each calculated molecular weight M i in the retention time from the calibration curve, also determine the fraction W i = h i / Σh i to the sum of the height h i of the chromatogram at each holding time, Based on these, the number average molecular weight Mn was obtained from 1 / {Σ (W i / M i )} and the weight average molecular weight Mw was obtained from Σ (W i · M i ).
The number average degree of polymerization N was determined by dividing the number average molecular weight Mn by the monomer unit molecular weight <m> averaged according to the charge ratio at the time of polymerization.

Figure 0005358903
なお、モノマー単位分子量＜ｍ＞は下記のとおり求めた。すなわち、複数種のテトラカルボン酸成分（分子量ｍ１，ｉ、仕込みモル比Ｒ１，ｉ、但し、ΣＲ１，ｉ＝１、ｉ＝１，２，３，・・・，ｎ１）、複数種のジアミン成分（分子量ｍ２，ｊ、仕込みモル比Ｒ２，ｊ、但し、ΣＲ２，ｊ＝１、ｊ＝１，２，３，・・・，ｎ２）を仕込んだ場合のモノマー単位分子量＜ｍ＞は下記の式に従って求めた。
Figure 0005358903
 The monomer unit molecular weight <m> was determined as follows. That is, plural types of tetracarboxylic acid components (molecular weight m 1, i , charged molar ratio R 1, i , where ΣR 1, i = 1, i = 1, 2, 3,..., N 1 ), plural Monomer unit in the case where seed diamine components (molecular weight m 2, j , charged molar ratio R 2, j , ΣR 2, j = 1, j = 1, 2, 3,..., N 2 ) are charged. The molecular weight <m> was determined according to the following formula.

Figure 0005358903
Figure 0005358903

（イミド化率の測定）
赤外分光法によるイミド化率の測定はパーキンエルマー社製スペクトラムワンを用い、全反射吸収測定法−フーリエ変換赤外分光法（ＡＴＲ−ＦＴＩＲ）によって行った。イミド化率ｐＩの算出は、イミド結合のＣ−Ｎ伸縮振動（波数約１３６０cm-1）の吸光度Ａを芳香核Ｃ＝Ｃ面内振動（波数約１５００cm-1）の吸光度ＡＩを内部標準として規格化した値（Ａ／ＡＩ）を、１９０℃にて５時間熱処理した後の試料について先と同様にして求めたＣ−Ｎ伸縮振動の吸光度ＡＳを芳香核Ｃ＝Ｃ面内振動の吸光度ＡＳＩを内部標準として規格化した値（ＡＳ／ＡＳＩ）で除して求めた。 (Measurement of imidization rate)
The imidation ratio was measured by infrared spectroscopy using Spectrum One manufactured by PerkinElmer Co., Ltd., by total reflection absorption measurement-Fourier transform infrared spectroscopy (ATR-FTIR). Calculation of imidization rate p I is the absorbance A I the internal standard C-N stretching vibration of an imide bond, an aromatic nucleus C = C-plane vibrations of the absorbance A of (wave number approximately 1360 cm -1) (a wave number of about 1500 cm -1) normalized value (a / a I) and 5 hours heat-treated samples for the previous and Similarly C-N stretching absorbance a S arom C = C-plane vibration of the vibration obtained after at 190 ° C. as The absorbance ASI was divided by a value normalized as an internal standard (A S / A SI ).

Figure 0005358903
なお、吸収バンドの吸光度は、吸収バンドの両側の谷を結んだ線をベースラインとしたピーク強度とした。
ここで得られたイミド化率の値から、さらに下記式により数平均重合度Ｎを求めた。
Figure 0005358903
 The absorbance of the absorption band was defined as the peak intensity with the line connecting the valleys on both sides of the absorption band as the baseline.
From the value of the imidization ratio obtained here, the number average degree of polymerization N was further determined by the following formula.

Figure 0005358903
ここでｒはポリイミドのテトラカルボン酸成分の総モル数に対するジアミン成分の総モル数の組成比であり、ジアミン成分がテトラカルボン酸成分より多い場合その逆数を取るものとし（即ちどの場合においてもｒは１以下）、ｐＩはイミド化率である。
Figure 0005358903
 Here, r is a composition ratio of the total number of moles of the diamine component to the total number of moles of the tetracarboxylic acid component of the polyimide, and when the diamine component is larger than the tetracarboxylic acid component, the reciprocal is taken (that is, in any case, r Is 1 or less), and p I is an imidization ratio.

（中空糸膜の酸素ガス、窒素ガス透過性能の測定方法）
６本の中空糸膜と、ステンレスパイプと、エポキシ樹脂系接着剤とを使用して有効長が８ｃｍの透過性能評価用のエレメントを作成し、これをステンレス容器に装着してペンシルモジュールとした。それに一定圧力のヘリウム、酸素、窒素標準混合ガス（容積比３０：３０：４０）を供給して透過流量および透過ガス組成を測定した。ガス組成はガスクロマトグラフ分析により求めた。測定した透過流量、透過ガス組成、供給圧、および有効膜面積から酸素ガス、および窒素ガスの透過速度を算出した。尚、これらの測定は５０℃で行った。 (Measurement of oxygen gas and nitrogen gas permeation performance of hollow fiber membranes)
An element for evaluating permeation performance having an effective length of 8 cm was prepared using six hollow fiber membranes, a stainless steel pipe, and an epoxy resin adhesive, and this was attached to a stainless steel container to form a pencil module. A constant pressure helium, oxygen, and nitrogen standard mixed gas (volume ratio 30:30:40) was supplied thereto, and a permeation flow rate and a permeated gas composition were measured. The gas composition was determined by gas chromatographic analysis. The permeation rate of oxygen gas and nitrogen gas was calculated from the measured permeation flow rate, permeated gas composition, supply pressure, and effective membrane area. These measurements were performed at 50 ° C.

（中空糸膜の引張強度と破断伸度の測定）
引張試験機を用いて有効長２０ｍｍ、引張速度１０ｍｍ／分で測定した。測定は２３℃で行った。中空糸断面積は中空糸の断面を光学顕微鏡で観察し、光学顕微鏡像から寸法を測定して算出した。 (Measurement of tensile strength and breaking elongation of hollow fiber membrane)
Using a tensile tester, measurement was performed at an effective length of 20 mm and a tensile speed of 10 mm / min. The measurement was performed at 23 ° C. The cross-sectional area of the hollow fiber was calculated by observing the cross-section of the hollow fiber with an optical microscope and measuring the dimensions from the optical microscope image.

本実施例における非対称中空糸膜の製造方法を説明する。
（非対称中空糸膜を製造する方法）
以下の例で用いた非対称中空糸膜の製造方法は、乾湿式紡糸法によって行った。具体的には、ポリイミド溶液を、４００メッシュの金網で濾過したあと、温度６５℃で中空糸紡糸ノズル（円形開口部外径１０００μｍ、円形開口部スリット幅２００μｍ、芯部開口部外径４００μｍ）から吐出させ、吐出した中空糸状態を窒素雰囲気中に通した後、０℃の７５重量％エタノール水溶液からなる凝固液に浸漬し湿潤糸とした。これを５０℃のエタノール中に２時間浸漬し脱溶媒処理を完了し、更に、７０℃のイソオクタン中に３時間浸漬洗浄して溶媒を置換後、１００℃絶乾状態で３０分間乾燥し、その後２５０〜３２０℃の温度で１時間の熱処理を行った。更に、中空糸膜の表面の滑りを整えるためにシリコンオイルでオイリング処理を施し中空糸膜を製造した。得られた中空糸膜はいずれも、大略、外径寸法４００μｍ、内径寸法２００μｍ、膜厚１００μｍのものであった。 The manufacturing method of the asymmetric hollow fiber membrane in a present Example is demonstrated.
(Method for producing an asymmetric hollow fiber membrane)
The method for producing the asymmetric hollow fiber membrane used in the following examples was performed by a dry and wet spinning method. Specifically, after the polyimide solution is filtered through a 400-mesh wire mesh, the hollow fiber spinning nozzle (circular opening outer diameter 1000 μm, circular opening slit width 200 μm, core opening outer diameter 400 μm) at a temperature of 65 ° C. After discharging and passing the discharged hollow fiber state through a nitrogen atmosphere, it was immersed in a coagulation liquid composed of a 75 wt% ethanol aqueous solution at 0 ° C. to obtain a wet thread. This was immersed in ethanol at 50 ° C. for 2 hours to complete the solvent removal treatment, and further washed by immersion in isooctane at 70 ° C. for 3 hours to replace the solvent, followed by drying at 100 ° C. in an absolutely dry state for 30 minutes. Heat treatment was performed at a temperature of 250 to 320 ° C. for 1 hour. Further, an oiling treatment was performed with silicone oil to prepare a hollow fiber membrane in order to adjust the slip of the surface of the hollow fiber membrane. All of the obtained hollow fiber membranes had an outer diameter of 400 μm, an inner diameter of 200 μm, and a film thickness of 100 μm.

〔実施例１〕
３，３’，４，４’−ビフェニルテトラカルボン酸二無水物（以下、ｓ−ＢＰＤＡと略記することもある）８．２１ｇと２，２’−ビス（３，４−ジカルボキシフェニル）ヘキサフルオロプロパン二無水物（以下、６ＦＤＡと略記することもある）１１．０２ｇとジメチル−３，７−ジアミノ−ジベンゾチオフェン−５，５−ジオキシド（以下、ＴＳＮと略記することもある）７．３７ｇと３，３’−５，５’−テトラクロロ−４，４’−ジアミノジフェニル（以下、ＴＣＢと略記することもある）８．６５ｇ（酸二無水物１モル部に対してジアミンが１．０２０モル部）を、溶媒のＰＣＰ１６３ｇと共にセパラブルフラスコ中にて反応温度１９０℃で２０時間重合してポリイミド溶液を得た。この溶液のポリイミドの重合度は４４であった。このポリイミド溶液へピロメリット酸二無水物（以下、ＰＭＤＡと略記することもある）２．０３ｇ、ＴＳＮ１．３０ｇ、ＴＣＢ１．５３ｇを溶媒のＰＣＰ２２ｇと共に添加した。この多成分ポリイミドの混合溶液をさらに反応温度１９０℃で１８時間重合イミド化し、ポリイミドの重合度が６５で、回転粘度が２５１１ポイズ、ポリマー濃度が１７重量％のポリイミド溶液を得た。（全原料組成として、酸二無水物１モル部に対してジアミンが１．０２０モル部）
この多成分ポリイミドの混合溶液を用いて、前記の非対称中空糸膜を製造する方法に基づいて、中空糸膜を製造した。この中空糸膜のガス透過性能と機械的特性を前記の方法によって測定した。
この中空糸膜の酸素ガス透過速度は６．８２×１０−５ｃｍ３（ＳＴＰ）／ｃｍ２・ｓｅｃ・ｃｍＨｇ、窒素ガス透過速度は１．３７×１０−５ｃｍ３（ＳＴＰ）／ｃｍ２・ｓｅｃ・ｃｍＨｇ、酸素ガスと窒素ガスの透過速度比は５．０であった。また、引張り強度は６ｋｇｆ／ｍｍ２、引張り破断伸度は３０％であった。 [Example 1]
8,21 g of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (hereinafter sometimes abbreviated as s-BPDA) and 2,2′-bis (3,4-dicarboxyphenyl) hexa 11.02 g of fluoropropane dianhydride (hereinafter sometimes abbreviated as 6FDA) and 7.37 g of dimethyl-3,7-diamino-dibenzothiophene-5,5-dioxide (hereinafter also abbreviated as TSN) And 3,3′-5,5′-tetrachloro-4,4′-diaminodiphenyl (hereinafter sometimes abbreviated as TCB) 8.65 g (1 part by mole of acid dianhydride is 1. 020 mol part) was polymerized in a separable flask together with 163 g of PCP as a solvent at a reaction temperature of 190 ° C. for 20 hours to obtain a polyimide solution. The degree of polymerization of the polyimide in this solution was 44. To this polyimide solution, 2.03 g of pyromellitic dianhydride (hereinafter sometimes abbreviated as PMDA), 1.30 g of TSN, and 1.53 g of TCB were added together with 22 g of PCP as a solvent. The mixed solution of the multi-component polyimide was further polymerized and imidized at a reaction temperature of 190 ° C. for 18 hours to obtain a polyimide solution having a polyimide polymerization degree of 65, a rotational viscosity of 2511 poise, and a polymer concentration of 17% by weight. (As a total raw material composition, 1.020 mol part of diamine with respect to 1 mol part of acid dianhydride)
Using this mixed solution of multi-component polyimide, a hollow fiber membrane was produced based on the above-described method for producing an asymmetric hollow fiber membrane. The gas permeation performance and mechanical properties of this hollow fiber membrane were measured by the above methods.
The hollow fiber membrane has an oxygen gas permeation rate of 6.82 × 10 −5 cm 3 (STP) / cm 2 · sec · cmHg, and a nitrogen gas permeation rate of 1.37 × 10 −5 cm 3 (STP) / cm 2. -Sec.cmHg, The permeation | transmission rate ratio of oxygen gas and nitrogen gas was 5.0. Further, the tensile strength was 6 kgf / mm 2 , and the tensile elongation at break was 30%.

〔比較例１〕
ｓ−ＢＰＤＡ８．２１ｇと６ＦＤＡ１１．０２ｇとＰＭＤＡ２．０３ｇとＴＳＮ８．６２ｇとＴＣＢ１０．１２ｇを、溶媒のＰＣＰ１８４ｇと共にセパラブルフラスコ中にて重合温度１９０℃で１８時間重合し、ポリイミドの重合度が９３で、回転粘度が２２５１ポイズ、ポリマー濃度が１７重量％のポリイミド溶液を得た。（酸二無水物１モル部に対してジアミンが１．０１３５モル部）
このポリイミド溶液は酸二無水物とジアミンとのモル比が弱冠ことなることを除けば、実施例１と基本的に同じ割合の原料組成をランダムに重合したものである。
このポリイミド溶液を用いて、前記の非対称中空糸膜を製造する方法に基づいて、中空糸膜を製造した。この中空糸膜のガス透過性能はと機械的特性を前記の方法によって測定した。
この中空糸膜の酸素ガス透過速度は４．８６×１０−５ｃｍ３（ＳＴＰ）／ｃｍ２・ｓｅｃ・ｃｍＨｇ、窒素ガス透過速度は０．９２×１０−５ｃｍ３（ＳＴＰ）／ｃｍ２・ｓｅｃ・ｃｍＨｇ、酸素ガスと窒素ガスの透過速度比は５．３であった。また、引張り強度は６ｋｇｆ／ｍｍ２、引張り破断伸度は８％であった。 [Comparative Example 1]
s-BPDA (8.21 g), 6FDA (11.02 g), PMDA (2.03 g), TSN (8.62 g) and TCB (10.12 g) were polymerized together with a solvent (PCP) of 184 g in a separable flask at a polymerization temperature of 190 ° C. for 18 hours. A polyimide solution having a rotational viscosity of 2251 poise and a polymer concentration of 17% by weight was obtained. (1.0135 mol parts of diamine with respect to 1 mol of acid dianhydride)
This polyimide solution is obtained by randomly polymerizing the raw material composition at basically the same ratio as in Example 1 except that the molar ratio of acid dianhydride and diamine is weak.
Using this polyimide solution, a hollow fiber membrane was produced based on the method for producing the asymmetric hollow fiber membrane. The gas permeation performance and mechanical properties of this hollow fiber membrane were measured by the method described above.
The hollow fiber membrane has an oxygen gas permeation rate of 4.86 × 10 −5 cm 3 (STP) / cm 2 · sec · cmHg, and a nitrogen gas permeation rate of 0.92 × 10 −5 cm 3 (STP) / cm 2. -Sec * cmHg and the permeation | transmission rate ratio of oxygen gas and nitrogen gas were 5.3. The tensile strength was 6 kgf / mm 2 and the tensile elongation at break was 8%.

〔実施例２〕
ｓ−ＢＰＤＡ９．１２ｇと６ＦＤＡ１１．０２ｇとＴＳＮ７．８１ｇとＴＣＢ９．１６ｇを、溶媒のＰＣＰ１７２ｇと共にセパラブルフラスコ中にて反応温度１９０℃で２０時間重合してポリイミド溶液を得た。この溶液のポリイミドの重合度は５７であった。このポリイミド溶液へＰＭＤＡ１．３５ｇ、ＴＳＮ０．８７ｇ、ＴＣＢ１．０２ｇを溶媒のＰＣＰ１４ｇと共に添加した。この多成分ポリイミドの混合溶液をさらに反応温度１９０℃で１８時間重合イミド化し、ポリイミドの重合度が６３で、回転粘度が１９５３ポイズ、ポリマー濃度が１７重量％のポリイミド溶液を得た。（全原料組成として、酸二無水物１モル部に対してジアミンが１．０２０モル部）
この多成分ポリイミドの混合溶液を用いて、前記の非対称中空糸膜を製造する方法に基づいて、中空糸膜を製造した。この中空糸膜のガス透過性能と機械的特性を前記の方法によって測定した。
この中空糸膜の酸素ガス透過速度は５．５５×１０−５ｃｍ３（ＳＴＰ）／ｃｍ２・ｓｅｃ・ｃｍＨｇ、窒素ガス透過速度は１．１２×１０−５ｃｍ３（ＳＴＰ）／ｃｍ２・ｓｅｃ・ｃｍＨｇ、酸素ガスと窒素ガスの透過速度比は５．０であった。また、引張り強度は６ｋｇｆ／ｍｍ２、引張り破断伸度は１７％であった。 [Example 2]
9.12 g of s-BPDA, 11.02 g of 6FDA, 7.81 g of TSN, and 9.16 g of TCB were polymerized in a separable flask together with 172 g of a solvent at a reaction temperature of 190 ° C. for 20 hours to obtain a polyimide solution. The degree of polymerization of polyimide in this solution was 57. To this polyimide solution, 1.35 g of PMDA, 0.87 g of TSN, and 1.02 g of TCB were added together with 14 g of PCP as a solvent. This mixed solution of multi-component polyimide was further polymerized and imidized at a reaction temperature of 190 ° C. for 18 hours to obtain a polyimide solution having a polyimide polymerization degree of 63, a rotational viscosity of 1953 poise, and a polymer concentration of 17% by weight. (As a total raw material composition, 1.020 mol part of diamine with respect to 1 mol part of acid dianhydride)
Using this mixed solution of multi-component polyimide, a hollow fiber membrane was produced based on the above-described method for producing an asymmetric hollow fiber membrane. The gas permeation performance and mechanical properties of this hollow fiber membrane were measured by the above methods.
The hollow fiber membrane has an oxygen gas permeation rate of 5.55 × 10 −5 cm 3 (STP) / cm 2 · sec · cmHg, and a nitrogen gas permeation rate of 1.12 × 10 −5 cm 3 (STP) / cm 2. -Sec.cmHg, The permeation | transmission rate ratio of oxygen gas and nitrogen gas was 5.0. The tensile strength was 6 kgf / mm 2 and the tensile elongation at break was 17%.

〔実施例３〕
ｓ−ＢＰＤＡ８．２１ｇとＰＭＤＡ２．０３ｇとＴＳＮ５．２０ｇとＴＣＢ６．１１ｇを、溶媒のＰＣＰ９９ｇと共にセパラブルフラスコ中にて反応温度１９０℃で１７時間重合してポリイミド溶液を得た。この溶液のポリイミドの重合度は８８であった。このポリイミド溶液へ６ＦＤＡ１１．０２ｇ、ＴＳＮ３．４７ｇ、ＴＣＢ４．０７ｇを溶媒のＰＣＰ８６ｇと共に添加した。この多成分ポリイミドの混合溶液をさらに反応温度１９０℃で１２時間重合イミド化し、ポリイミドの重合度が６９で、回転粘度が１６００ポイズ、ポリマー濃度が１７重量％のポリイミド溶液を得た。（全原料組成として、酸二無水物１モル部に対してジアミンが１．０２０モル部）
この多成分ポリイミドの混合溶液を用いて、前記の非対称中空糸膜を製造する方法に基づいて、中空糸膜を製造した。この中空糸膜のガス透過性能と機械的特性を前記の方法によって測定した。
この中空糸膜の酸素ガス透過速度は６．５９×１０−５ｃｍ３（ＳＴＰ）／ｃｍ２・ｓｅｃ・ｃｍＨｇ、窒素ガス透過速度は１．２７×１０−５ｃｍ３（ＳＴＰ）／ｃｍ２・ｓｅｃ・ｃｍＨｇ、酸素ガスと窒素ガスの透過速度比は５．２であった。また、引張り強度は６ｋｇｆ／ｍｍ２、引張り破断伸度は２４％であった。 Example 3
A polyimide solution was obtained by polymerizing 8.21 g of s-BPDA, 2.03 g of PMDA, 5.20 g of TSN, and 6.11 g of TCB together with 99 g of PCP as a solvent in a separable flask at a reaction temperature of 190 ° C. for 17 hours. The degree of polymerization of polyimide in this solution was 88. To this polyimide solution were added 11.02 g of 6FDA, 3.47 g of TSN, and 4.07 g of TCB together with 86 g of PCP as a solvent. This mixed solution of the multi-component polyimide was further polymerized and imidized at a reaction temperature of 190 ° C. for 12 hours to obtain a polyimide solution having a polyimide polymerization degree of 69, a rotational viscosity of 1600 poise, and a polymer concentration of 17% by weight. (As a total raw material composition, 1.020 mol part of diamine with respect to 1 mol part of acid dianhydride)
Using this mixed solution of multi-component polyimide, a hollow fiber membrane was produced based on the above-described method for producing an asymmetric hollow fiber membrane. The gas permeation performance and mechanical properties of this hollow fiber membrane were measured by the above methods.
The hollow fiber membrane has an oxygen gas permeation rate of 6.59 × 10 −5 cm 3 (STP) / cm 2 · sec · cmHg, and a nitrogen gas permeation rate of 1.27 × 10 −5 cm 3 (STP) / cm 2. -Sec * cmHg, The permeation | transmission rate ratio of oxygen gas and nitrogen gas was 5.2. The tensile strength was 6 kgf / mm 2 and the tensile elongation at break was 24%.

〔実施例４〕
ｓ−ＢＰＤＡ１０．９４ｇとＴＳＮ５．２０ｇとＴＣＢ６．１１ｇを、溶媒のＰＣＰ１０２ｇと共にセパラブルフラスコ中にて反応温度１９０℃で２０時間重合してポリイミド溶液を得た。この溶液のポリイミドの重合度は７７であった。このポリイミド溶液へ６ＦＤＡ１１．０２ｇ、ＴＳＮ３．４７ｇ、ＴＣＢ４．０７ｇを溶媒のＰＣＰ８６ｇと共に添加した。この多成分ポリイミドの混合溶液をさらに反応温度１９０℃で２０時間重合イミド化し、ポリイミドの重合度が７６で、回転粘度が２００９ポイズ、ポリマー濃度が１７重量％のポリイミド溶液を得た。（全原料組成として、酸二無水物１モル部に対してジアミンが１．０２０モル部）
この多成分ポリイミドの混合溶液を用いて、前記の非対称中空糸膜を製造する方法に基づいて、中空糸膜を製造した。この中空糸膜のガス透過性能と機械的特性を前記の方法によって測定した。
この中空糸膜の酸素ガス透過速度は７．６３×１０−５ｃｍ３（ＳＴＰ）／ｃｍ２・ｓｅｃ・ｃｍＨｇ、窒素ガス透過速度は１．５５×１０−５ｃｍ３（ＳＴＰ）／ｃｍ２・ｓｅｃ・ｃｍＨｇ、酸素ガスと窒素ガスの透過速度比は４．９であった。また、引張り強度は５ｋｇｆ／ｍｍ２、引張り破断伸度は１６％であった。 Example 4
s-BPDA (10.94 g), TSN (5.20 g), and TCB (6.11 g) were polymerized in a separable flask with a solvent of PCP (102 g) at a reaction temperature of 190 ° C. for 20 hours to obtain a polyimide solution. The degree of polymerization of polyimide in this solution was 77. To this polyimide solution were added 11.02 g of 6FDA, 3.47 g of TSN, and 4.07 g of TCB together with 86 g of PCP as a solvent. This mixed solution of multi-component polyimide was further polymerized and imidized at a reaction temperature of 190 ° C. for 20 hours to obtain a polyimide solution having a degree of polymerization of 76, a rotational viscosity of 2009 poise, and a polymer concentration of 17% by weight. (As a total raw material composition, 1.020 mol part of diamine with respect to 1 mol part of acid dianhydride)
Using this mixed solution of multi-component polyimide, a hollow fiber membrane was produced based on the above-described method for producing an asymmetric hollow fiber membrane. The gas permeation performance and mechanical properties of this hollow fiber membrane were measured by the above methods.
The hollow fiber membrane has an oxygen gas permeation rate of 7.63 × 10 −5 cm 3 (STP) / cm 2 · sec · cmHg, and a nitrogen gas permeation rate of 1.55 × 10 −5 cm 3 (STP) / cm 2. -Sec * cmHg and the permeation | transmission rate ratio of oxygen gas and nitrogen gas were 4.9. The tensile strength was 5 kgf / mm 2 and the tensile elongation at break was 16%.

〔比較例２〕
ｓ−ＢＰＤＡ１０．９４ｇと６ＦＤＡ１１．０２ｇとＴＳＮ８．６７ｇとＴＣＢ１０．１８ｇを、溶媒のＰＣＰ１８８ｇと共にセパラブルフラスコ中にて重合温度１９０℃で２９時間重合し、ポリイミドの重合度が５５で、回転粘度が１２０９ポイズ、ポリマー濃度が１７重量％のポリイミド溶液を得た。（酸二無水物１モル部に対してジアミンが１．０２０モル部）
このポリイミド溶液は実施例４と基本的に同じ割合の原料組成をランダムに重合したものである。
このポリイミド溶液を用いて、前記の非対称中空糸膜を製造する方法に基づいて、中空糸膜を製造した。この中空糸膜のガス透過性能はと機械的特性を前記の方法によって測定した。
この中空糸膜の酸素ガス透過速度は４．１８×１０−５ｃｍ３（ＳＴＰ）／ｃｍ２・ｓｅｃ・ｃｍＨｇ、窒素ガス透過速度は０．８８×１０−５ｃｍ３（ＳＴＰ）／ｃｍ２・ｓｅｃ・ｃｍＨｇ、酸素ガスと窒素ガスの透過速度比は４．８であった。また、引張り強度は５ｋｇｆ／ｍｍ２、引張り破断伸度は６％であった。 [Comparative Example 2]
s-BPDA (10.94 g), 6FDA (11.02 g), TSN (8.67 g) and TCB (10.18 g) were polymerized together with a solvent (PCP) of 188 g in a separable flask at a polymerization temperature of 190 ° C. for 29 hours. A polyimide solution having 1209 poise and a polymer concentration of 17% by weight was obtained. (1.020 mol part of diamine with respect to 1 mol part of acid dianhydride)
This polyimide solution is obtained by randomly polymerizing a raw material composition at basically the same ratio as in Example 4.
Using this polyimide solution, a hollow fiber membrane was produced based on the method for producing the asymmetric hollow fiber membrane. The gas permeation performance and mechanical properties of this hollow fiber membrane were measured by the method described above.
The hollow fiber membrane has an oxygen gas permeation rate of 4.18 × 10 −5 cm 3 (STP) / cm 2 · sec · cmHg, and a nitrogen gas permeation rate of 0.88 × 10 −5 cm 3 (STP) / cm 2. -Sec * cmHg and the permeation | transmission rate ratio of oxygen gas and nitrogen gas were 4.8. The tensile strength was 5 kgf / mm 2 and the tensile elongation at break was 6%.

〔実施例５〕
６ＦＤＡ１１．０２ｇとＴＳＮ３．４７ｇとＴＣＢ４．０７ｇを、溶媒のＰＣＰ８６ｇと共にセパラブルフラスコ中にて反応温度１９０℃で３５時間重合してポリイミド溶液を得た。この溶液のポリイミドの重合度は４２であった。このポリイミド溶液へｓ−ＢＰＤＡ８．２１ｇ、ＰＭＤＡ２．０３ｇ、ＴＳＮ５．２０ｇ、ＴＣＢ６．１１ｇを溶媒のＰＣＰ９９ｇと共に添加した。この多成分ポリイミドの混合溶液をさらに反応温度１９０℃で２５時間重合イミド化し、ポリイミドの重合度が５９で、回転粘度が２１２０ポイズ、ポリマー濃度が１７重量％のポリイミド溶液を得た。（全原料組成として、酸二無水物１モル部に対してジアミンが１．０２０モル部）
この多成分ポリイミドの混合溶液を用いて、前記の非対称中空糸膜を製造する方法に基づいて、中空糸膜を製造した。この中空糸膜のガス透過性能と機械的特性を前記の方法によって測定した。
この中空糸膜の酸素ガス透過速度は５．４８×１０−５ｃｍ３（ＳＴＰ）／ｃｍ２・ｓｅｃ・ｃｍＨｇ、窒素ガス透過速度は１．０９×１０−５ｃｍ３（ＳＴＰ）／ｃｍ２・ｓｅｃ・ｃｍＨｇ、酸素ガスと窒素ガスの透過速度比は５．０であった。また、引張り強度は７ｋｇｆ／ｍｍ２、引張り破断伸度は４０％であった。 Example 5
6FDA (11.02 g), TSN (3.47 g) and TCB (4.07 g) were polymerized in a separable flask together with a solvent (PCP) (86 g) at a reaction temperature of 190 ° C. for 35 hours to obtain a polyimide solution. The degree of polymerization of polyimide in this solution was 42. To this polyimide solution, 8.21 g of s-BPDA, 2.03 g of PMDA, 5.20 g of TSN, and 6.11 g of TCB were added together with 99 g of PCP as a solvent. This mixed solution of multi-component polyimide was further polymerized and imidized at a reaction temperature of 190 ° C. for 25 hours to obtain a polyimide solution having a polyimide polymerization degree of 59, a rotational viscosity of 2120 poise, and a polymer concentration of 17% by weight. (As a total raw material composition, 1.020 mol part of diamine with respect to 1 mol part of acid dianhydride)
Using this mixed solution of multi-component polyimide, a hollow fiber membrane was produced based on the above-described method for producing an asymmetric hollow fiber membrane. The gas permeation performance and mechanical properties of this hollow fiber membrane were measured by the above methods.
The hollow fiber membrane has an oxygen gas permeation rate of 5.48 × 10 −5 cm 3 (STP) / cm 2 · sec · cmHg, and a nitrogen gas permeation rate of 1.09 × 10 −5 cm 3 (STP) / cm 2. -Sec.cmHg, The permeation | transmission rate ratio of oxygen gas and nitrogen gas was 5.0. The tensile strength was 7 kgf / mm 2 and the tensile elongation at break was 40%.

〔比較例３〕
ｓ−ＢＰＤＡ８．２１ｇと６ＦＤＡ６．８９ｇとＴＳＮ６．０７ｇとＴＣＢ７．１３ｇを、溶媒のＰＣＰ１２９ｇと共にセパラブルフラスコ中にて反応温度１９０℃で２０時間重合してポリイミド溶液を得た。この溶液のポリイミドの重合度は５３であった。このポリイミド溶液へ６ＦＤＡ４．１３ｇ、ＰＭＤＡ２．０３ｇ、ＴＳＮ２．６０ｇ、ＴＣＢ３．０５ｇを溶媒のＰＣＰ５６ｇと共に添加した。この多成分ポリイミドの混合溶液をさらに反応温度１９０℃で２０時間重合イミド化し、ポリイミドの重合度が６１で、回転粘度が１１１６ポイズ、ポリマー濃度が１７重量％のポリイミド溶液を得た。（全原料組成として、酸二無水物１モル部に対してジアミンが１．０２０モル部）
この多成分ポリイミドの混合溶液を用いて、前記の非対称中空糸膜を製造する方法に基づいて、中空糸膜を製造した。この中空糸膜のガス透過性能と機械的特性を前記の方法によって測定した。
この中空糸膜の酸素ガス透過速度は５．１３×１０−５ｃｍ３（ＳＴＰ）／ｃｍ２・ｓｅｃ・ｃｍＨｇ、窒素ガス透過速度は１．００×１０−５ｃｍ３（ＳＴＰ）／ｃｍ２・ｓｅｃ・ｃｍＨｇ、酸素ガスと窒素ガスの透過速度比は５．１であった。また、引張り強度は６ｋｇｆ／ｍｍ２、引張り破断伸度は８％であった。 [Comparative Example 3]
A polyimide solution was obtained by polymerizing 8.21 g of s-BPDA, 6.89 g of 6FDA, 6.07 g of TSN, and 7.13 g of TCB together with 129 g of the solvent in a separable flask at a reaction temperature of 190 ° C. for 20 hours. The degree of polymerization of polyimide in this solution was 53. To this polyimide solution, 4.13 g of 6FDA, 2.03 g of PMDA, 2.60 g of TSN, and 3.05 g of TCB were added together with 56 g of PCP as a solvent. The mixed solution of the multi-component polyimide was further polymerized and imidized at a reaction temperature of 190 ° C. for 20 hours to obtain a polyimide solution having a polyimide polymerization degree of 61, a rotational viscosity of 1116 poise, and a polymer concentration of 17% by weight. (As a total raw material composition, 1.020 mol part of diamine with respect to 1 mol part of acid dianhydride)
Using this mixed solution of multi-component polyimide, a hollow fiber membrane was produced based on the above-described method for producing an asymmetric hollow fiber membrane. The gas permeation performance and mechanical properties of this hollow fiber membrane were measured by the above methods.
The hollow fiber membrane has an oxygen gas permeation rate of 5.13 × 10 −5 cm 3 (STP) / cm 2 · sec · cmHg, and a nitrogen gas permeation rate of 1.00 × 10 −5 cm 3 (STP) / cm 2. -Sec * cmHg, The permeation | transmission rate ratio of oxygen gas and nitrogen gas was 5.1. The tensile strength was 6 kgf / mm 2 and the tensile elongation at break was 8%.

〔実施例６〕
６ＦＤＡ１１．０２ｇ、ＴＳＮ３．４７ｇとＴＣＢ４．０７ｇを、溶媒のＰＣＰ８６ｇと共にセパラブルフラスコ中にて反応温度１９０℃で３５時間重合してポリイミド溶液を得た。この溶液のポリイミドの重合度は１３であった。このポリイミド溶液へｓ−ＢＰＤＡ１０．９４ｇ、ＴＳＮ５．２０ｇ、ＴＣＢ６．１１ｇを溶媒のＰＣＰ１０２ｇと共に添加した。この多成分ポリイミドの混合溶液をさらに反応温度１９０℃で３８時間重合イミド化し、ポリイミドの重合度が３１で、回転粘度が１３９５ポイズ、ポリマー濃度が１７重量％のポリイミド溶液を得た。（全原料組成として、酸二無水物１モル部に対してジアミンが１．０２０モル部）
この多成分ポリイミドの混合溶液を用いて、前記の非対称中空糸膜を製造する方法に基づいて、中空糸膜を製造した。この中空糸膜のガス透過性能と機械的特性を前記の方法によって測定した。
この中空糸膜の酸素ガス透過速度は５．５３×１０−５ｃｍ３（ＳＴＰ）／ｃｍ２・ｓｅｃ・ｃｍＨｇ、窒素ガス透過速度は１．０２×１０−５ｃｍ３（ＳＴＰ）／ｃｍ２・ｓｅｃ・ｃｍＨｇ、酸素ガスと窒素ガスの透過速度比は５．４であった。また、引張り強度は６ｋｇｆ／ｍｍ２、引張り破断伸度は２５％であった。 Example 6
6FDA 11.02g, TSN 3.47g and TCB 4.07g were polymerized together with solvent PCP86g in a separable flask at a reaction temperature of 190 ° C for 35 hours to obtain a polyimide solution. The degree of polymerization of polyimide in this solution was 13. To this polyimide solution, 10.94 g of s-BPDA, 5.20 g of TSN, and 6.11 g of TCB were added together with 102 g of PCP as a solvent. This mixed solution of multi-component polyimide was further polymerized and imidized at a reaction temperature of 190 ° C. for 38 hours to obtain a polyimide solution having a polyimide polymerization degree of 31, a rotational viscosity of 1395 poise, and a polymer concentration of 17% by weight. (As a total raw material composition, 1.020 mol part of diamine with respect to 1 mol part of acid dianhydride)
Using this mixed solution of multi-component polyimide, a hollow fiber membrane was produced based on the above-described method for producing an asymmetric hollow fiber membrane. The gas permeation performance and mechanical properties of this hollow fiber membrane were measured by the above methods.
The hollow fiber membrane has an oxygen gas permeation rate of 5.53 × 10 −5 cm 3 (STP) / cm 2 · sec · cmHg, and a nitrogen gas permeation rate of 1.02 × 10 −5 cm 3 (STP) / cm 2. -Sec * cmHg and the permeation | transmission rate ratio of oxygen gas and nitrogen gas were 5.4. The tensile strength was 6 kgf / mm 2 and the tensile elongation at break was 25%.

〔実施例７〕
ｓ−ＢＰＤＡ２．７４ｇ、ＰＭＤＡ２．０３ｇ、ＴＳＮ２．６０ｇとＴＣＢ３．０５ｇを、溶媒のＰＣＰ４８ｇと共にセパラブルフラスコ中にて反応温度１９０℃で２０時間重合してポリイミド溶液を得た。この溶液のポリイミドの重合度は３５であった。このポリイミド溶液へ６ＦＤＡ１１．０２ｇ、ｓ−ＢＰＤＡ５．４７ｇ、ＴＳＮ６．０７ｇ、ＴＣＢ７．１３ｇを溶媒のＰＣＰ１３７ｇと共に添加した。この多成分ポリイミドの混合溶液をさらに反応温度１９０℃で２４時間重合イミド化し、ポリイミドの重合度が４２で、回転粘度が１８９７ポイズ、ポリマー濃度が１７重量％のポリイミド溶液を得た。（全原料組成として、酸二無水物１モル部に対してジアミンが１．０２０モル部）
この多成分ポリイミドの混合溶液を用いて、前記の非対称中空糸膜を製造する方法に基づいて、中空糸膜を製造した。この中空糸膜のガス透過性能と機械的特性を前記の方法によって測定した。
この中空糸膜の酸素ガス透過速度は７．１９×１０−５ｃｍ３（ＳＴＰ）／ｃｍ２・ｓｅｃ・ｃｍＨｇ、窒素ガス透過速度は１．４７×１０−５ｃｍ３（ＳＴＰ）／ｃｍ２・ｓｅｃ・ｃｍＨｇ、酸素ガスと窒素ガスの透過速度比は４．９であった。また、引張り強度は７ｋｇｆ／ｍｍ２、引張り破断伸度は３９％であった。 Example 7
2.74 g of s-BPDA, 2.03 g of PMDA, 2.60 g of TSN and 3.05 g of TCB were polymerized together with 48 g of the solvent PCP in a separable flask at a reaction temperature of 190 ° C. for 20 hours to obtain a polyimide solution. The degree of polymerization of polyimide in this solution was 35. To this polyimide solution, 11.02 g of 6FDA, 5.47 g of s-BPDA, 6.07 g of TSN, and 7.13 g of TCB were added together with 137 g of the solvent PCP. This mixed solution of multi-component polyimide was further polymerized and imidized at a reaction temperature of 190 ° C. for 24 hours to obtain a polyimide solution having a polyimide polymerization degree of 42, a rotational viscosity of 1897 poise and a polymer concentration of 17% by weight. (As a total raw material composition, 1.020 mol part of diamine with respect to 1 mol part of acid dianhydride)
Using this mixed solution of multi-component polyimide, a hollow fiber membrane was produced based on the above-described method for producing an asymmetric hollow fiber membrane. The gas permeation performance and mechanical properties of this hollow fiber membrane were measured by the above methods.
This hollow fiber membrane has an oxygen gas transmission rate of 7.19 × 10 −5 cm 3 (STP) / cm 2 · sec · cmHg, and a nitrogen gas transmission rate of 1.47 × 10 −5 cm 3 (STP) / cm 2. -Sec * cmHg and the permeation | transmission rate ratio of oxygen gas and nitrogen gas were 4.9. The tensile strength was 7 kgf / mm 2 and the tensile elongation at break was 39%.

〔実施例８〕
６ＦＤＡ１１．０２ｇ、ｓ−ＢＰＤＡ５．４７ｇ、ＴＳＮ６．０７ｇとＴＣＢ７．１３ｇを、溶媒のＰＣＰ１３７ｇと共にセパラブルフラスコ中にて反応温度１９０℃で２０時間重合してポリイミド溶液を得た。この溶液のポリイミドの重合度は２１であった。このポリイミド溶液へｓ−ＢＰＤＡ２．７４ｇ、ＰＭＤＡ２．０３ｇ、ＴＳＮ２．６０ｇ、ＴＣＢ３．０５ｇを溶媒のＰＣＰ４８ｇと共に添加した。この多成分ポリイミドの混合溶液をさらに反応温度１９０℃で３２時間重合イミド化し、ポリイミドの重合度が２７で、回転粘度が１４６９ポイズ、ポリマー濃度が１７重量％のポリイミド溶液を得た。（全原料組成として、酸二無水物１モル部に対してジアミンが１．０２０モル部）
この多成分ポリイミドの混合溶液を用いて、前記の非対称中空糸膜を製造する方法に基づいて、中空糸膜を製造した。この中空糸膜のガス透過性能と機械的特性を前記の方法によって測定した。
この中空糸膜の酸素ガス透過速度は８．３８×１０−５ｃｍ３（ＳＴＰ）／ｃｍ２・ｓｅｃ・ｃｍＨｇ、窒素ガス透過速度は１．７３×１０−５ｃｍ３（ＳＴＰ）／ｃｍ２・ｓｅｃ・ｃｍＨｇ、酸素ガスと窒素ガスの透過速度比は４．８であった。また、引張り強度は６ｋｇｆ／ｍｍ２、引張り破断伸度は２７％であった。 Example 8
6FDA 11.02 g, s-BPDA 5.47 g, TSN 6.07 g and TCB 7.13 g were polymerized together with solvent PCP 137 g in a separable flask at a reaction temperature of 190 ° C. for 20 hours to obtain a polyimide solution. The degree of polymerization of polyimide in this solution was 21. To this polyimide solution, 2.74 g of s-BPDA, 2.03 g of PMDA, 2.60 g of TSN, and 3.05 g of TCB were added together with 48 g of PCP as a solvent. This mixed solution of the multi-component polyimide was further polymerized and imidized at a reaction temperature of 190 ° C. for 32 hours to obtain a polyimide solution having a polyimide polymerization degree of 27, a rotational viscosity of 1469 poise, and a polymer concentration of 17% by weight. (As a total raw material composition, 1.020 mol part of diamine with respect to 1 mol part of acid dianhydride)
Using this mixed solution of multi-component polyimide, a hollow fiber membrane was produced based on the above-described method for producing an asymmetric hollow fiber membrane. The gas permeation performance and mechanical properties of this hollow fiber membrane were measured by the above methods.
This hollow fiber membrane has an oxygen gas permeation rate of 8.38 × 10 −5 cm 3 (STP) / cm 2 · sec · cmHg, and a nitrogen gas permeation rate of 1.73 × 10 −5 cm 3 (STP) / cm 2. -Sec * cmHg and the permeation | transmission rate ratio of oxygen gas and nitrogen gas were 4.8. The tensile strength was 6 kgf / mm 2 and the tensile elongation at break was 27%.

本発明によって、特定のポリイミドによって形成された非対称中空糸ガス分離膜において、分離性能を大幅に低下させることなく、機械的強度を改善した非対称中空糸ガス分離膜を提供すること、更に前記非対称中空糸ガス分離膜を用いて酸素ガスと窒素ガスを含む混合ガスから選択的に酸素ガスを透過させてガス分離を行うガス分離方法を提供することができる。   According to the present invention, an asymmetric hollow fiber gas separation membrane formed of a specific polyimide is used to provide an asymmetric hollow fiber gas separation membrane with improved mechanical strength without significantly reducing the separation performance. It is possible to provide a gas separation method in which gas separation is performed by selectively permeating oxygen gas from a mixed gas containing oxygen gas and nitrogen gas using a yarn gas separation membrane.

：ＮＡとＮＢとの組合せ範囲を説明するためのグラフである。: Is a graph illustrating the combined range of N A and N B. ：本発明の非対称中空糸ガス分離膜を用いたガス分離膜モジュール: Gas separation membrane module using the asymmetric hollow fiber gas separation membrane of the present invention

符号の説明Explanation of symbols

１：混合ガス供給口
２：非透過ガス排出口
３：透過ガス排出口
４：管板
５：中空糸膜
６：容器 1: Mixed gas supply port 2: Non-permeate gas discharge port 3: Permeate gas discharge port 4: Tube plate 5: Hollow fiber membrane 6: Container

Claims (6)

実質的に下記一般式（１）
Figure 0005358903
 ［但し、一般式（１）中のＡは、その２０〜８０モル％が式（２）
Figure 0005358903
 で示されるビフェニル構造に基く４価のユニットで、２０〜８０モル％が式（３）
Figure 0005358903
 で示されるジフェニルヘキサフルオロプロパン構造に基づく４価のユニットで、０〜３０モル％が式（４）
Figure 0005358903
 で示されるフェニル構造に基づく４価のユニットで、一般式（１）中のＲは、その３０〜７０モル％が式（５）又は／及び式（６）
Figure 0005358903
 （式中、Ｒ１及びＲ２は水素原子または有機基であり、ｎは０、１又は２である。）
Figure 0005358903
 （式中、Ｒ１及びＲ２は水素原子または有機基であり、Ｘは−ＣＨ２−又は−ＣＯ−である。）
で示される２価のユニットで、３０〜７０モル％が式（７）
Figure 0005358903
 （式中、Ｙは塩素原子又は臭素原子であり、ｎは１〜３である。）
で示されるビフェニル構造に基づく２価のユニットである。］からなる反復単位を有するポリイミドによって形成された非対称中空糸ガス分離膜であって、
式（３）で示されるジフェニルヘキサフルオロプロパン構造を含むポリイミドＡの原料成分及び／又は前記原料成分の重合イミド化反応物をポリイミド成分Ａとし、前記ポリイミド成分Ａの数平均重合度をＮ Ａ とし、式（３）で示されるジフェニルヘキサフルオロプロパン構造を含まないポリイミドＢの原料成分及び／又は前記原料成分の重合イミド化反応物をポリイミド成分Ｂとし、前記ポリイミド成分Ｂの数平均重合度をＮ Ｂ としたときに、
（１）ポリイミド成分Ａとポリイミド成分Ｂとを、Ｎ Ａ とＮ Ｂ とが下記数式１を満たす組合せで混合して多成分ポリイミドの混合溶液を調製し、
Figure 0005358903
 （２）前記多成分ポリイミドの混合溶液をさらに重合イミド化反応させ、次いで、
（３）前記多成分ポリイミドの混合溶液を用いて相転換法によって非対称膜を得る、
ことを特徴とする、非対称中空糸ガス分離膜であって、
中空糸膜としての引張り破断伸度が１５％以上である非対称中空糸ガス分離膜。
ここで、Ｎ Ａ 及びＮ Ｂ は、ポリイミド原料である未反応のテトラカルボン酸成分とジアミン成分の重合度をそれぞれ０．５として算出する。 The following general formula (1)
Figure 0005358903
 [However, A in the general formula (1) is 20 to 80 mol% of the formula (2)
Figure 0005358903
 Is a tetravalent unit based on the biphenyl structure represented by the formula (3):
Figure 0005358903
 Is a tetravalent unit based on the diphenylhexafluoropropane structure represented by the formula (4):
Figure 0005358903
 In the general formula (1), 30 to 70 mol% of the R in the general formula (1) is represented by the formula (5) or / and the formula (6).
Figure 0005358903
 (Wherein R1 and R2 are a hydrogen atom or an organic group, and n is 0, 1 or 2)
Figure 0005358903
 (In the formula, R 1 and R 2 are a hydrogen atom or an organic group, and X is —CH 2 — or —CO—.)
30-70 mol% is a divalent unit represented by the formula (7)
Figure 0005358903
 (In the formula, Y is a chlorine atom or a bromine atom, and n is 1 to 3.)
It is a bivalent unit based on the biphenyl structure shown by these. An asymmetric hollow fiber gas separation membrane formed of a polyimide having a repeating unit consisting of
The polymerization and imidation reaction product of raw material components and / or the ingredients of the polyimide A including a diphenylhexafluoropropane structure represented by the formula (3) a polyimide component A, a number average degree of polymerization of the polyimide component A and N A the polymerization and imidation reaction product of raw material components and / or the ingredients of polyimide B without a diphenylhexafluoropropane structure represented by the formula (3) a polyimide component B, the number average polymerization degree of the polyimide component B N when a B,
(1) a polyimide components A and B, and the N A and N B to prepare a mixed solution of mixed and polyimide components in combination which satisfies the following formula 1,
Figure 0005358903
 (2) The mixed solution of the multi-component polyimide is further polymerized imidized,
(3) An asymmetric membrane is obtained by a phase conversion method using the mixed solution of the multi-component polyimide.
An asymmetric hollow fiber gas separation membrane characterized in that
An asymmetric hollow fiber gas separation membrane having a tensile elongation at break of 15% or more as a hollow fiber membrane.
Here, N A and N B calculates a degree of polymerization of the tetracarboxylic acid component and diamine component of the unreacted with polyimide material as 0.5, respectively. ５０℃で測定した酸素ガスの透過速度（Ｐ’Ｏ２）が４．０×１０−５ｃｍ３（ＳＴＰ）／ｃｍ２・ｓｅｃ・ｃｍＨｇ以上且つ窒素ガスの透過速度に対する酸素ガスの透過速度の比（Ｐ’Ｏ２／Ｐ’Ｎ２）が４以上であることを特徴とする請求項１に記載の非対称中空糸ガス分離膜。 The oxygen gas permeation rate ( P′O2 ) measured at 50 ° C. is 4.0 × 10 −5 cm 3 (STP) / cm 2 · sec · cmHg or more, and the ratio of the oxygen gas permeation rate to the nitrogen gas permeation rate The asymmetric hollow fiber gas separation membrane according to claim 1, wherein ( P'O2 / P'N2 ) is 4 or more. 請求項１〜２のいずれかに記載の非対称中空糸ガス分離膜の供給側に、酸素ガスと窒素ガスを含む混合ガスを接触させ、前記非対称中空糸ガス分離膜の透過側へ酸素ガスを選択的に透過させることによって、酸素ガスと窒素ガスを含む混合ガスから、酸素ガスが富化した混合ガスと窒素ガスが富化した混合ガスとを分離回収することを特徴とするガス分離方法。   A mixed gas containing oxygen gas and nitrogen gas is brought into contact with the supply side of the asymmetric hollow fiber gas separation membrane according to claim 1 and oxygen gas is selected on the permeation side of the asymmetric hollow fiber gas separation membrane. The gas separation method is characterized by separating and recovering the mixed gas enriched with oxygen gas and the mixed gas enriched with nitrogen gas from the mixed gas containing oxygen gas and nitrogen gas by permeation. 非対称中空糸ガス分離膜の内側を供給側とし、非対称中空糸ガス分離膜の外側を透過側とすることを特徴とする前記請求項３に記載のガス分離方法。   The gas separation method according to claim 3, wherein the inside of the asymmetric hollow fiber gas separation membrane is the supply side and the outside of the asymmetric hollow fiber gas separation membrane is the permeation side. 請求項１〜２のいずれかに記載の非対称中空糸ガス分離膜の多数本を束ねた中空糸束と、前記中空糸束の少なくとも一方の端部において各中空糸膜を開口させた状態で包埋して固着した管板とを必須とした中空糸エレメントを、混合ガス供給口、非透過ガス排出口、及び透過ガス排出口を備えた容器内に、前記非対称中空糸ガス分離膜の内側の空間と外側の空間とが隔絶されるようにして収納したことを特徴とする中空糸ガス分離膜モジュール。   A hollow fiber bundle in which a large number of asymmetric hollow fiber gas separation membranes according to any one of claims 1 to 2 are bundled, and each hollow fiber membrane is wrapped in at least one end of the hollow fiber bundle. A hollow fiber element essentially including a tube plate that is buried and fixed is placed inside a container having a mixed gas supply port, a non-permeate gas discharge port, and a permeate gas discharge port, inside the asymmetric hollow fiber gas separation membrane. A hollow fiber gas separation membrane module characterized in that the space and the outer space are isolated from each other. 実質的に前記一般式（１）からなる反復単位を有するポリイミドによって形成された非対称中空糸ガス分離膜であって、
式（３）で示されるジフェニルヘキサフルオロプロパン構造を含むポリイミドＡの原料成分及び／又は前記原料成分の重合イミド化反応物をポリイミド成分Ａとし、前記ポリイミド成分Ａの数平均重合度をＮＡとし、さらに、式（３）で示されるジフェニルヘキサフルオロプロパン構造を含まないポリイミドＢの原料成分及び／又は前記原料成分の重合イミド化反応物をポリイミド成分Ｂとし、前記ポリイミド成分Ｂの数平均重合度をＮＢとしたときに、
（１）ポリイミド成分Ａとポリイミド成分Ｂとを、ＮＡとＮＢとが下記数式１を満たす組合せで混合して多成分ポリイミドの混合溶液を調製し、
Figure 0005358903
 （２）前記多成分ポリイミドの混合溶液をさらに重合イミド化反応させ、次いで、
（３）前記多成分ポリイミドの混合溶液を用いて相転換法によって非対称膜を得る、
ことを特徴とする請求項１に記載の非対称中空糸ガス分離膜の製造方法。
ここで、ＮＡ及びＮＢは、ポリイミド原料である未反応のテトラカルボン酸成分とジアミン成分の重合度をそれぞれ０．５として算出する。 An asymmetric hollow fiber gas separation membrane formed of polyimide having a repeating unit substantially consisting of the general formula (1),
The polymerization and imidation reaction product of raw material components and / or the ingredients of the polyimide A including a diphenylhexafluoropropane structure represented by the formula (3) a polyimide component A, a number average degree of polymerization of the polyimide component A and N A Furthermore, the raw material component of polyimide B not containing the diphenylhexafluoropropane structure represented by formula (3) and / or the polymerization imidization reaction product of the raw material component is polyimide component B, and the number average degree of polymerization of the polyimide component B is the when and N B,
(1) a polyimide components A and B, and the N A and N B to prepare a mixed solution of mixed and polyimide components in combination which satisfies the following formula 1,
Figure 0005358903
 (2) The mixed solution of the multi-component polyimide is further polymerized imidized,
(3) An asymmetric membrane is obtained by a phase conversion method using the mixed solution of the multi-component polyimide.
The method for producing an asymmetric hollow fiber gas separation membrane according to claim 1.
Here, N A and N B calculates a degree of polymerization of the tetracarboxylic acid component and diamine component of the unreacted with polyimide material as 0.5, respectively.
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