JPS60197207A - Preparation of organic high-molecular membrane - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for preparing an organic polymer film that can control substance selection function.

In recent years, membrane technologies that utilize permeability or selective permeability have been developed in a wide range of fields such as engineering, medicine, and agriculture.
Desalination membranes, dialysis membranes for artificial kidneys, ion exchange membranes, etc. are being put into practice. Furthermore, recently, as an energy-saving technology, the development of specific and highly functional membranes such as oxygen enrichment membranes, resource separation membranes, and charge separation membranes has become increasingly important.

For example, regarding oxygen enrichment membranes, their materials include porous polymer membranes (Japanese Patent Laid-Open No. 55-8803), fluorine-containing silicone rubber-porous polytetrafluoroethylene (Japanese Patent Laid-Open No. 56-5121), Cross-linked polyorganosiloxane-linear polyorganosiloxane copolymer (JP-A-5
6-26508), cellulose monocarboxylic acid ester (% JP-A-56-26526), styrene siloxane polymer α, ω-2 functional polysiloxane cross-linked polymer (JP-A-56-28604, etc.), etc. is being done. However, each material has an insufficient balance in gas permeability coefficient, separation coefficient, or film thickness that can be manufactured.

On the other hand, many methods for preparing organic polymer films have also been proposed. For example, there may be mentioned a method of forming a film by casting onto a water surface or a method of forming a film on a porous support by plasma gas phase polymerization (Japanese Patent Application Laid-open No. 41958/1984, etc.). However, there is still a strong need in the industry today for a reliable and reproducible method for producing thin organic polymer films with a practical area.

The present inventors have conducted extensive research to solve the conventional problems with organic polymer film materials and methods for forming the same, and have completed the present invention.

That is, the method for preparing an organic polymer membrane capable of controlling the substance selection function of the present invention is a method of preparing a halogenated vinyl polymer and/or a copolymer of a monomer copolymerizable with vinyl halide and vinyl halide; A composition containing a nematic liquid crystal substance is dissolved in a mixed solvent of a good solvent and a poor solvent for the (co)polymer to obtain a polymer solution, and the polymer solution is spread on a water surface to form a film. It is characterized by this.

Examples of copolymers of halogenated vinyl polymers and/or monomers copolymerizable with vinyl halides and vinyl halides used in the present invention include polyvinyl chloride, polyvinyl bromide, and polyvinyl chloride. , vinyl chloride
Vinyl acetate copolymer, vinyl chloride-ethylene copolymer,
Vinyl chloride-propylene copolymer, vinyl chloride-styrene copolymer, vinyl chloride-isobutylene copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-styrene-maleic anhydride terpolymer, vinyl chloride- Styrene-acrylonitrile copolymer, vinyl chloride-butadiene copolymer, vinyl chloride-impre/copolymer, vinyl chloride-chlorinated propylene copolymer, vinyl chloride-chlorinated vinylidene-vinyl acetate terpolymer, chloride Examples include vinyl-acrylic acid ester copolymer, vinyl chloride-maleic acid ester copolymer, vinyl chloride-acrylonitrile copolymer, and the like. The halogenated vinyl polymer referred to in the present invention also includes polytetraph 471% ethylene, polytetrafluorochloroethylene, polyvinylidene fluoride, polyvinylidene chloride, and the like. These polymers can be selected from a wide range depending on the purpose and usage of the film, as long as they are compatible with the nematic liquid crystal material. For example, for use as an oxygen enrichment membrane, polymers with suitable solvents are advantageous.

Examples of the nematic liquid crystal material used in the present invention include methoxybenzylidene-pn-butylaniline, ethoxybenzylidene-pn-butylaniline,
n-probyloxybenzyliden-pn-butylaniline, n-2) xybenzylidene-pn-butylaniline, methoxybenzylidene-pn-amylaniline, ethoxypensylidene-p
-n-amylaniline, n-probyloxybenzylidene-p-n-7-mylaniline, n-γtoxybenzylidene-p-n-amylaniline, n-amyloxybenzylidene-p-n-amylaniline, methoxybenzylidene-p -n-hexylaniline%' p-anicylidene-p-aminophenyl acetate, p-anicylidene-
p-aminobenzonitrile, p-azoxyanisole,
p-ethoxy-p/ nihexanonyloxyazobenzene, p-n-hexylbenzoic acid-p'-n
-hexyloxyphenyl ester, butyl-(4'-
ethoxyphenoxycarbonyl)-7x dicarbonate (BEPCPC), N-4-bentroxycarbonyloxybenzylidene-4'-anisidine (PCBA),
4-n-heptyloxybenzoic acid (HBA)
, N, N'-bis-p-methoxybenzylidene-3,
Examples include 3'-dichlorobendiazine (MBDB).

The amount of nematic liquid crystal material used depends on the purpose of use.
For 95 to 5 parts by weight of vinyl halide (co)polymer,
It can be appropriately selected from the range of 5 to 95 parts by weight.

In the present invention, a material selectivity improver can also be used in combination with the mixture of vinyl halide (C) MU and nematic liquid crystal material. The substance selectivity enhancer is selected from a wide range of substances depending on the intended use of the membrane. For example, when the organic polymer membrane according to the present invention is used as an oxygen-enriching membrane, a substance with a high oxygen uptake capacity is advantageously selected as the substance selectivity improver. For example, perfluorotributylamine, non-fluorodecalin, perfluoromethyldecalin, perfluorotetrahydrofuran, bar-7-fluorobutyltetrahydrofuran, etc. Also, when a crown ether is used as a substance selectivity improver,
An organic polymer membrane that selectively transmits metal ions can be obtained. Furthermore, when azo crown ether is used, it is possible to obtain, for example, an organic polymer film in which the transport of K ions can be accelerated by light. The amount of the material selectivity improver to be added is determined as appropriate, taking into consideration the type of organic polymer compound used in the organic polymer film, the type and amount of the nematic liquid crystal substance used, and the like. Furthermore, a surfactant or the like may be added to improve the dispersion of the substance selectivity improver.

Examples of good solvents for the halogenated vinyl (co)polymer used in the present invention include cyclohexanone, tetrahydrofuran, and butanone. As the poor solvent, a solvent such as benzene, toluene, and tetrachloroethylene is selected that is a poor solvent and is easily developed on the water surface. The ratio of good and poor solvents should be determined so that the polymer solution spreads easily on the water surface and controls the material selection function when forming a film on the water surface. This is determined as appropriate depending on the type of polymer and the type of good/poor solvent in order to obtain a porous membrane that can be used as a porous membrane. , a larger amount of toluene gives better results.

A polymer solution prepared by dissolving a composition containing a halogenated (co)polymer and a nematic liquid crystal substance in a mixed solvent of good and poor solvents is spread on the water surface by a conventional method, the film is taken out from the water surface, and the By drying and removing it, it is possible to obtain an organic polymer thin film that can control the multi-substance selection function. According to the method of the present invention, by changing the quantitative ratio of good and poor solvents, it is possible to freely produce membranes with different ability to control substance selection functions, so they can be adjusted according to the purpose. By laminating them together, they can be used for a variety of purposes.

Therefore, the organic polymer membrane produced according to the present invention can specifically control the selection function of various substances, and can be widely used as an oxygen enrichment membrane, resource separation membrane, charge separation membrane, etc. It has a range. Furthermore, since it contains a nematic liquid crystal material, the alignment of the liquid crystal can be controlled by applying an electric field, thereby making it possible to specifically control the membrane permeability of gases and other various substances.

The present invention will be specifically explained below using Examples 8. Example 8 Polyvinyl chloride (degree of polymerization 1050) (PVC) powder, N
-(4-Ethoxybenzylidene) 4/++ n-butylaniline (EBBA) and azocrown were mixed in a weight ratio of 40:60:5.2,
Mixed solvent of tetrahydrofuran (THF) and toluene (
Prepare two types with a weight ratio of 1/1 and 1/2),
A 10% by weight polymer solution was obtained.

A drop of this polymer solution was gently dropped on the wall of the water surface in a water tank maintained at 283K to form a thin film on the water surface.
It was immediately scooped up and dried under vacuum at room temperature to obtain a film (water surface spread film) (about 400 cm thick) with a thickness of about 70 nm.

After laminating 20 sheets of this water-surface-deployable membrane on a Teflon plate, the membrane was fixed to a ring-shaped frame, peeled off from the frame, and heat-treated for several minutes at 333 °C in a nitrogen atmosphere to form a wrinkle-free and sagging-free membrane (cast membrane). ) was prepared.

In addition, the film developed on the water surface was scooped onto a specimen stage for electron microscope observation (copper mesh coated with carbon), and the copper mesh was immersed in 100 mA of methanol at about 333° C. for about 12 hours. After extracting the azocrown, it was observed using a transmission electron microscope.

Figure 1 is an electron micrograph of a water surface developed film when a mixed solvent of tetrahydrofuran/toluene = 171 (weight ratio) is used, and Figure 2 is an electron micrograph of a film developed on a water surface using a mixed solvent of tetrahydrofuran/toluene = 1/1/toluene.
There is an electron micrograph taken when a mixed solvent of 2 (weight ratio) was used.

The polymer film produced according to the present invention is as shown in the figure.
The liquid crystal has a network structure), and the liquid crystal is a continuous phase in the laminated film.

PVC/EBBA=40/60 (weight ratio) to THF/
) The oxygen permeation rate of the thin film developed using a mixed solvent of toluene = 1/2 (weight ratio) was measured. FIG. 3 is an Arrhenius plot of oxygen permeation rate RO2.

For comparison, FIG. 3 also shows an Arrhenius φ plot for a film with a thickness of about 400 μm obtained by casting a mixture of PVC/EBBA=40/60 (weight ratio) on a glass surface.

[Brief explanation of the drawing]

FIG. 1 is an electron micrograph after liquid crystal and azo crown were extracted and removed from a thin film obtained by developing on water using a mixed solvent of THF/)luene=1/1 (weight ratio). FIG. 2 is an electron micrograph after liquid crystal and azo crown were extracted and removed from a thin film obtained by developing on water using a mixed solvent of THF/)luene=1/2 (weight ratio). Figure 3 shows PVC/EBBA=40/60 (weight ratio)
This is an Arrhenius plot of the oxygen permeation rate of a cast film obtained by developing the above on the water surface using a mixed solvent of THF/toluene = 1/2 (weight ratio). In the figure, 1 shows the product developed on the water surface, and 2 shows the product cast on the glass surface. jp 3 Indentation 10'/T Procedural amendment (method) Manabu Shiga, Commissioner of the Japan Patent Office, dated 25th April 1982, 1, Indication of case, Patent Application No. 52265, 1982, 2,
Title of the invention: Method for preparing organic polymer membranes 3, relationship with the amended case Patent applicant address: 3-2-5-4 Kasumigaseki, Chiyoda-ku, Tokyo 100
, date of amendment order June 26, 1980 (shipment date),
Ru. ``Figure 1 shows the surface structure of a thin film developed on a water surface after liquid crystals and azo crowns were extracted and removed from the thin film obtained by developing it on a water surface using a mixed solvent of THF/)luene = 1/1 (weight ratio). This is a micrograph. Figure 2 shows the surface of a thin film developed on a water surface after liquid crystal and azo crown were extracted and removed from the thin film obtained by developing it on a water surface using a mixed solvent of THF/)luene = 1/2 (weight ratio). This is an electron micrograph showing the structure. Figure 3 is obtained by developing PVC/EBBA = 40/60 (weight ratio) on the water surface using a mixed solvent of THF/) luene = 1/2 (weight ratio). This is an Arrhenius plot of the oxygen permeation rate of a cast film. In the figure, 1 shows the film developed on the water surface, and 2 shows the film cast on the glass surface.

Claims (1)

[Claims] A composition containing a halogenated vinyl polymer and/or a monomer copolymerizable with vinyl halide, a copolymer of vinyl halide, and a nematic liquid crystal material;
An organic material capable of controlling a substance selection function, characterized in that a polymer solution is obtained by dissolving the polymer in a mixed solvent of a good solvent and a poor solvent, and the polymer solution is spread on a water surface to form a film. Method for preparing polymer membranes.