JPH06126140A - Multilayer gas separation film - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] The separation performance and permeation performance of oxygen can be improved,
Provided is a gas separation composite membrane capable of suppressing deterioration due to the influence of a use environment and improving initial performance and durability. [Structure] The gas separation composite membrane is composed of a support membrane layer made of a porous material, a separation layer provided on the support membrane layer by water surface development, and a protection layer provided on the separation layer by water surface development. . In the separation layer, mono- or di-substituted polydiphenylacetylene represented by the following formula,
A material in which a polymer having a higher tensile strength than that of the mono- or di-substituted polydiphenylacetylene is mixed is used, and a siloxane compound is used for the protective layer. (In the formula, R ₁ represents an alkyl group or a trialkylsilyl group, R ₂ represents an alkyl group which may be substituted with a halogen atom, a trialkylsilyl group or a halogen atom;
Represents an integer of 40 to 40,000. )

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a gas separation composite membrane for separating and concentrating oxygen and nitrogen in the air.

[0002]

2. Description of the Related Art In recent years, gas separation membranes are capable of separating oxygen and nitrogen with a simple structure, and therefore, research has been conducted for use in combustion equipment, air conditioning equipment, medical equipment and the like, and some of them have been put to practical use.

Conventionally, a gas separation membrane of this type has been disclosed in JP-A-56-26.
There was one as shown in Japanese Patent No. 504. That is, it is mainly composed of a copolymer of a polyorganosiloxane having active hydrogen in the side chain and a polyorganosiloxane having a vinyl group in the side chain. The separation coefficient of oxygen and nitrogen of this membrane is about 2.2 for PO ₂ / PN ₂ , and the permeability coefficient of oxygen is 2.8.
× 10 to ⁸ cm ³ (STP) · cm / cm ² · sec · cmHg. Further, as a film having a high separation coefficient, there is a film as disclosed in JP-A-56-146277. This is a composite film mainly composed of poly (4-methylpentene-1) as a gas separating film and formed from an ultrathin film having a film thickness of 1 micron or less and a porous material supporting the ultrathin film. The separation coefficient of oxygen and nitrogen of this composite membrane is P
O ₂ / PN ₂ is about 4.5, and oxygen transmission coefficient is 3.4 × 10 ~ ⁹
It is about cm ³ (STP) / cm / cm ² · sec · cmHg.

[0004]

However, in the above-mentioned conventional gas separation membrane, since the separation coefficient and the permeability coefficient of oxygen are contradictory to each other, in order to obtain high concentration and high flow rate of oxygen, There is a drawback that a large film area is required and the cost is high, and it is not satisfactory for practical use.

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a gas separation composite membrane capable of improving oxygen separation performance and oxygen permeation performance.

[0006]

In order to achieve the above object, the present invention provides a support membrane layer made of a porous material, a separation layer provided on the support membrane layer, and a protection provided on the separation layer. A material obtained by mixing the monosubstituted or disubstituted polydiphenylacetylene represented by the chemical formula 2 with a polymer having a higher tensile strength than the monosubstituted or disubstituted polydiphenylacetylene. A siloxane compound is used for the protective layer.

[0007]

[Chemical 2]

[0008]

According to the present invention, by interposing a polymer having a higher tensile strength than the mono- or di-substituted polydiphenylacetylene represented by the chemical formula (2), the mechanical strength of the membrane is improved and an ultrathin film is formed. It becomes possible, the permeation coefficient can be improved, and by combining the separation layer formed by mixing the polymer with the support membrane layer, a high gas separation property can be obtained by the interaction at the interface between the separation layer and the support membrane layer. Further, the siloxane-based compound provided as the protective film layer acts to activate gas permeation of the film and can improve the permeation coefficient.

[0009]

EXAMPLES Examples of the present invention will be described below with reference to the cross-sectional view of the gas separation composite membrane shown in FIG. As shown in FIG. 1, the gas separation composite membrane 1 includes a support membrane layer 2 made of a polyethersulfone porous material, a separation layer 3 provided on the upper surface of the support membrane layer 2, and a protection provided on the separation layer 3. It is constituted by the layer 4. As the separation layer 3,
It is a mixture of a mono- or di-substituted polydiphenylacetylene represented by the chemical formula 2 and a polymer having a higher tensile strength than the polydiphenylacetylene.

Example 1 A poly (1- (p-trimethylsilylphenyl) -2-phenylacetylene) in which R ₁ of the mono- or di-substituted polydiphenylacetylene represented by the formula (2) is substituted with a trimethylsilyl group is used. 0.5% by weight, 0.3% by weight of polytrimethylsilylpropyne (hereinafter abbreviated as PTMSP) as a polymer having higher tensile strength than this polydiphenylacetylene, and 0.2% by weight of polyfumarate as a water surface developing agent, chlorobutane and toluene. , And an organic solvent of tetrahydrofuran (the weight ratio of each of chlorobutane, toluene, and tetrahydrofuran is 150: 8: 5) to prepare a preparation liquid for the separation layer 3.

The protective layer 4 contains 3.4% by weight of a copolymer of siloxane compound and styrene and 0.1% by weight of polyfumarate ester as a water surface developing agent, and an organic solvent of chlorobutane and tetrahydrofuran (weight of chlorobutane and tetrahydrofuran). The ratio is 20: 1) to prepare a preparation liquid.

Then, a fixed amount of the preparation liquid for the separation layer 3 is spread on the water surface, and the solvent is evaporated to obtain an average film thickness of 0.1.
A separation layer 3 having a thickness of 03 μm is formed, and two layers of the separation layer 3 are laminated on the support membrane layer 2 by contacting the support membrane layer 2, and a fixed amount of the protective layer 4 is spread on the water surface to evaporate the solvent As a result, a thin film having an average film thickness of 0.02 μm is produced, and two protective layers 4 are further laminated on the surface thereof. The initial performance of the gas separation composite membrane produced in this way is shown in Example 1 (Table 1).
Shown in.

Example 2 Instead of poly (1- (p-trimethylsilylphenyl) -2-phenylacetylene), R ₁ of the mono- or di-substituted polydiphenylacetylene represented by the formula (2) is t-butyl. A poly (1-substituted by a group
(pt-butylphenyl) -2-phenylacetylene)
A gas separation composite membrane was produced in the same manner as in Example 1 except that was used. The performance of the obtained gas separation composite membrane is shown in Example 2 of (Table 1).

Example 3 Instead of poly (1- (p-trimethylsilylphenyl) -2-phenylacetylene), R ₁ of the mono- or di-substituted polydiphenylacetylene represented by the formula (2) is a trimethylsilyl group, A gas separation composite membrane was produced in the same manner as in Example 1 except that poly (1- (p-trimethylsilylphenyl) -2- (p-fluorophenyl) acetylene) in which R ₂ was substituted with a fluorine atom was used. . The performance of the obtained gas separation composite membrane is shown in Example 3 of (Table 1).
Shown in.

As described above, in each of the examples, the mono- or di-substituted polydiphenylacetylene represented by the chemical formula (2) and the PTMSP having a higher tensile strength than the mono- or di-substituted polydiphenylacetylene are mixed as the separation layer 3. By doing so, and by providing the protective layer 4 made of a siloxane-based compound on the surface of the separation layer 3, film formation is easy, and deterioration due to the influence of the surrounding environment such as dust, dust, humidity, and heat can be prevented.

[0016]

[Table 1]

In each of the above examples, PTMSP was used as the polymer having a higher tensile strength than the mono- or di-substituted polydiphenylacetylene represented by the formula (2).
It may be poly (4-methylpentene-1), polyphenylene oxide, a cellulosic polymer, or the like. Further, although the support membrane layer uses polyether sulfone, a material formed of a polymer such as polysulfone, polystyrene, polyethylene terephthalate may be used, and the shape of the support membrane layer may be a flat membrane, a tubular membrane, a hollow fiber membrane. Etc., or a film formed on a support such as a woven fabric or a non-woven fabric.

Further, in order to obtain a good thin film on the surface of the separation layer, a surface development aid may be added if necessary, and the protective layer uses a copolymer of a siloxane compound and styrene. , A quick-drying dealcohol type adhesive sealant, a solvent type silicone for peeling, or a blend thereof may be used.

[0019]

As described above, the gas separation composite membrane of the present invention comprises a support membrane layer made of a porous material, a separation layer provided on the support membrane layer, and a protective layer provided on the separation layer. And a material obtained by mixing the mono-substituted or di-substituted polydiphenylacetylene represented by the chemical formula 2 with a polymer having a higher tensile strength than the mono-substituted or di-substituted polydiphenyl acetylene. The protective layer uses a siloxane-based compound, and with this structure, oxygen separation performance, permeation performance, and durability can be improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a gas separation composite membrane in an example of the present invention.

[Explanation of symbols]

1 ... Gas separation composite membrane, 2 ... Support membrane layer, 3 ... Separation layer,
4 ... Protective layer.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masanori Kimura 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Masato Otsubo 1-2-1, Yokou, Kawasaki-ku, Kanagawa Prefecture Zeon Japan R & D Center Co., Ltd. (72) Inventor Sumi Watanabe 1-2-1, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Zeon Corporation R & D Center (72) Inventor Takeshi Tahara 1-chome, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture 2-1 Japan Zeon Co., Ltd. Research and Development Center

Claims (1)

[Claims] 1. A support membrane layer made of a porous material, a separation layer provided on the support membrane layer, and a protective layer provided on the separation layer, wherein the separation layer has the formula (1) A material obtained by mixing a mono- or di-substituted polydiphenylacetylene shown with a polymer having a higher tensile strength than the mono- or di-substituted polydiphenylacetylene is used, and a siloxane compound is used for the protective layer. Gas separation composite membrane. [Chemical 1]