JPS5955309A - Composite molding for separating gas - Google Patents

Abstract

PURPOSE:To provide a composite molding for separating gas having high separating power for gas by providing a low temp. plasma polymer film of an org. compd. to the molding having a specific oxygen permeation characteristic. CONSTITUTION:A titled composite molding is produced by providing a low temp. plasma polymer film having 0.01-1mum film thickness consisting of an org. silicon compd. on a molding having >=1X10<-3>cm<2>.cm/cm<2>.sec.cmHg coefft. of oxygen permeation in a gas permeation section and has >=2.5 coefft. of sepn. For example, a silicone rubber sheet having 50mum thickness obtd. by a calendering method is set in a plasma generator, and after the inside of the generator is evacuated down to 10<-4>Torr, the vapor of trimethyl vinyl silane as an org. monomer is introduced into the generator and is adjusted and maintained to and at 0.2Torr while the vapor is kept flowed. High frequency electric powder of 13.56MHz and 150W is applied to the same in this state to generate the low temp. plasma of trimethyl vinyl silane, thereby forming a plasma polymer film on the silicone rubber sheet. The coefft. of permeation oxygen of the film is 3.0X10<-8> without the plasma treatment and 2.4X10<-8> with the treatment and the sepn. rate for nitrogen is increased from 2.0 to 3.1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a composite molded article for gas separation that has good gas permeability and excellent gas selection functions, and is particularly suitable for obtaining oxygen-enriched air from air. The purpose of the present invention is to provide a composite molded article for gas separation.

Recently, there has been remarkable progress and development in separation technology using polymer membranes such as ultrafiltration membranes, reverse osmosis membranes, gas permeation membranes, etc., and some of them have been put into practical use on an industrial scale. However, the methods that are actually put into practical use include desalination of seawater, treatment of factory waste liquid, concentration of foods (liquid substances), liquid-liquid separation or liquid-solid separation, and gas-gas separation, i.e. Enrichment or separation of specific gases from a mixture of more than one species remains at the research stage.

As a seamount for which this gas separation membrane has not been put into practical use, the selective permeability is small, that is, there is no possibility that a specific gas will pass through the selective gate and almost no other gas will pass through.
In order to obtain high-purity gas, it is necessary to adopt a multi-stage method in which membrane separation is repeated several times, which makes the equipment too large and the permeation flow rate is small, making it impossible to produce a large amount of gas.

The problem with gas separation membrane technology is how to increase the permeate flow rate per unit area of the membrane without reducing its separation capacity7)x.

In addition, there is an inversely proportional relationship between the thickness of the separation membrane and the permeation flow rate.
Increasing the permeate flow rate requires decreasing the membrane thickness. However, when the film is made thinner, pinholes, Bragg formations, and thickness unevenness tend to occur, making it difficult to manufacture a thin film with uniform gas permeability, and there is also the problem that gas force releasability gradually decreases. , just by making the separation membrane thinner, the u + r
ll ability cannot be achieved.

On the other hand, from the point of view of selective permeability, there are many fields in which a high-purity gas is not necessarily required as a final use.For example, in the case of oxygen, it is used for blast furnace ventilation, combustion assistance, waste liquid treatment aeration, and single-gas treatment. If the air is so-called oxygen-enriched air for breath 2, etc., this purpose will be achieved.

However, the conventional method for obtaining oxygen-enriched air is to produce high-purity oxygen using an air separation device (air liquefaction method), and then mix it with air to obtain the desired oxygen-enriched air. However, in this case, the high-purity oxygen is contained in a pressure vessel, which poses problems such as handling risks and the complexity of operations to maintain a constant mixed gas concentration. do not have.

On the other hand, by dropping an organopolysilochitin-polycarbonate copolymer solution onto the surface of a liquid casting support, an ultra-thin membrane can be made, and this membrane can be used as a gas separation membrane to release oxygen-enriched air. Method of obtaining (Unexamined Japanese Patent Publication No. 54-4
0868) has also been attempted. This method uses an ultra-thin membrane to increase the amount of gas permeation, but it has a thickness of 0.5 mm without a support. It is extremely difficult to stably produce a film of about I/Im, and there are also problems in that it is troublesome to handle such an ultra-thin film when it is incorporated into a device. has not yet been reached.

The present inventors have conducted extensive research to solve these problems, and as a result 1, for example, the reproducibility of film formation is good.

We have completed a composite molded body for gas separation that is relatively easy to handle69, has a high gas separation ability, and has a large permeation flow rate per unit area.

However, the present invention has an oxygen permeability coefficient of 1 in a gas permeable part made of an organic polymer material or an inorganic porous material.
xlOclI-tTn/M・sec・cm Hg or more This relates to a composite molded product for gas separation with a separation coefficient of 2.5 or more, which is obtained by providing a low-grade plasma composite film of a roofing compound on a molded product with a temperature of 2.5 or more. The object of the present invention is to provide a composite molded body for gas separation, which is particularly suitable for obtaining oxygen-enriched air from air.

According to the present invention, the composite molded product for gas separation, such as a film state, has excellent "performance" with a separation coefficient of 2.5 or more, even if the base film has some bottle holes, Bragg, etc. Since it is covered by the low-temperature plasma polymerized film formed thereon, it is easy to make the separation film thinner, and high gas separation performance is achieved.

The present invention will be explained in detail below.

Formed bodies used in the present invention include film-sheets, hollow bodies or hollow fibers made of general organic polymer materials, sintered bodies of plastics, and non-porous porous materials. The molded bodies of various shapes are colored, and the gas permeable part of these molded bodies is
l.sec.Rust Hg or higher is required. If the oxygen permeability coefficient is smaller than this, the permeation flow V11 per unit surface area will be small rx, resulting in inferior separation performance on the same industrial scale.

Yugo Toki's molecular material is polyethylene.

Hollybrobylene, polycellulose acetate, polycarbonate, polyethylene terephthalate.

Polyvinyl alcohol, polystyrene, polysulfone
Aromatic polyester, polyvinyl chloride, polyethylene resin, fluorine thread resin, silicone resin, etc.
Porous materials include gold, sintered minerals, porcelain, earthenware, unglazed ceramics, new ceramic rugs, and the like. Rub 1. Materials must be selected to be advantageous depending on the target gas content, type of W, and other purposes; for example, for FFJ, which carries more oxygen than air, F) r4g It is advantageous to use a material with excellent cumulative permeability, and this? l+'μ point Karage silicone resin is said to be a good choice.

These silicone resins include methyl thread polyoxyaxane, phenyl thread polysiloxane, σ chitin, methylphenyl polysiloxane, vinyl polysiloxane, and other polysiloxanes having alkyl groups substituted with alkyl, halogen, or cyano groups. , mixtures thereof, or copolymers of these with other organic compounds, such as silicone-carbonate copolymers, 1,7 silicone-urethane copolymers, silicone-acrylic copolymers, and modified polysiloxanes, such as amino and f-based polysiloxanes, and epoxy threads. Modified polysiloxanes, agril-modified polysiloxanes, polyether-modified polysiloxanes, phenol-modified polysiloxanes, and the like are included.

The structure of these silicone resins is tin cane.

It may be branched or net-like, and a curing agent may be added according to the required vtc 7J1. It is also possible to make it more biased than the IVC.

For example, a curing catalyst or barboxide may be used for thermosetting polysiloxane, and oxime-free polysiloxane may be used for thermosetting polysiloxane.

It includes various types such as deacetic acid type, dealcoholized type, and deacetonized type.

The method of obtaining the above-mentioned molded bodies from T-i 1'l Crystal Molecule Tei 4 materials is Nishinomiya's extrusion molding-compression molding,
The molding method is not limited, and may be any method such as calendering, molding, or casting. Furthermore, in the case of inorganic porous materials, as long as the oxygen permeability coefficient satisfies the above-mentioned value, conventionally known molding methods can be used, and molded bodies of various shapes such as plate-like bodies, sheet-like bodies, and tubular bodies can be produced. It will be done.

The complex acid 4-form for gas separation, which is an alternative to the sword 1 of the present invention, is made by providing a low-temperature plasma polymerized film of an organic compound on the surface of a molded body having the above-mentioned predetermined oxygen permeability coefficient, and is used here. As the organic compound, Natsuki silicon compounds, organic fluorine compounds, hydrocarbon compounds, and 7-4tlJ organic compounds are selectively used. A specific example is as follows.

Trimethylglor7zolan- Trimethylmethoxysilane, trimethylethoxysilane, vinyldimethylglorosilane, vinyldimethylmethoxysilane, vinyldimethylethoxysilane, ethynyldimethylmethoxyv+/ran, ethynyldimethylglorovran, methylgloromethylmethoxyglorosilane , triethylmethoxysilane-dimethylchloromethylethoxysilane. dimethylchloride a
o Methylglorosilane, dimethylphenylmethoxysilane.

2-Gloroethynyldimethylgloclsilane, 2-Gloroethynyldimethylmethoxyvran, dimethyldiglorosilane-dimethyldimethoxysilane, dimethyljethoxysilane, dimethyljethoxysilane, vinylmethyldiglorosilane, vinylmethyldimethoxysilane, 2-Chloroethylmethyldimethoxysilane, vinylmethyljethoxysilane, methylmethyldimethoxysilane, dimethoxymethylphenylsilane, methylmethyldimethoxyvlan, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane , phenyltrimethoxysilane, chloromethyltrimethoxysilane, 2-chloroethyltrimethoxysilane, trifluorobiltrigloa silane, tetravinylsilane, trivinylmethylsilane, divinyldimethylsilane, vinyltrimethylsilane, divinyltetramethyldiνloxane-diglomethylsilane Tetramethyldisiloxane, jetynyltetramethyldisiloxane, tetramethyldityldisilazane, ogtamethylsiglotetrasiloxane, hexamethylsilphenylene.

Monochlorotrifluoromethane, jig difluoromethane, monoglo difluoromethane, trifluor a trifluoroethane, jig tetrafluoroethane, monoglo pentafluoroethane.

Tetrafluoroethylene, hexafluoropropylene,
Perfluoro a bread, tetrafluoromethane% 1.
1-difluoroethylene, trifluoromethane, fluoromethane, ogutafluorosyglobutane, difluoroethane, gross difluoroethane, hexafluoroethane, chloropentafluoroethane, dibromotetrafluoroethane.

Methane, ethane, propane, pentane, hexane, ethylene, propylene, butene, heptene.

Butadiene, propadiene-hexatriene, methylpropene, dimethylhexadiene, di-a-hexane, cyglopentene, V-glohexene, V-glohexadiene, benzene, toluene, xylene.

Naphthalene-styrene, methylstyrene, pentamethylbenzene, hexamethylbenzene, divinylbenzene,
Allylbenzene, vinylnaphthalene.

Budanol, methylamine, heptanone, gloromethylpropane, vallonitrile, gloroacetonitrile, methacrylic acid, methyl methacrylate-acrylic acid, maleic acid, allylamine, allylmethylamine, agrilonitrile, tetracyanonitrile, methacrylate nitrile, vinylene Carbonate, acrolein, allyl bromide, glolobropene, vinyl chloride-vinylidene chloride, allyl alcohol, chlorobenzene-trichlorobenzene, benzonitrile, toluidine.

Nitrotoluene + N, N-i)) Thia 1z
) 7L/(i)n.

N-nitrosodiethylamine, aniline, methylaniline, phthalate-phenol, benzaldehyde, V-glohexenol, pyridine, vinylpyridine, vinylmethylpyridine, picoline, ferrocene, vinylferroyan, thiophene, dihydrofuran, N-nitrosopiperidine.

Each persimmon organic compound mentioned above is not limited to one type of persimmon, and two or more types can be used in combination, but organic silicon compounds, especially organic silicon compounds having unsaturated bonds in the molecule, have excellent oxygen permeability. Preference is given to using the compound primarily UF+.

A method for forming a low-temperature plasma polymerized film on the surface of a compact is to place the compact into a low-temperature plasma generator, and to flow the organic compound gas through the device for 10 minutes.
The method is to adjust and maintain the pressure to below Torr, generate low-temperature plasma under this gas pressure, and expose the product to the low-temperature plasma. active gas, air, #, grass,
Inorganic gases such as hydrogen, water vapor, carbon dioxide, -yoshikako, and +e may also coexist.

In the above method, if the pressure of the gas of the compound (1) in the apparatus is too high, it will be difficult to form a plasma polymerized film on the surface of the body (b), so the gas pressure of this low temperature plasma i'[ 10) It is preferable that it is less than 1, and if waiting 5~
0.005) is desirable. This low-temperature plasma in the gas upper blade absorbs a polymeric film having excellent gas separation properties. The desired thickness of the plasma polymerized film formed in this manner (F6) is 0.
01-1 μm.

In addition, the conditions for generating low 7h^ plasma are as follows.

for example? Q411 (6C10KHz ~100MHz-
A power of 1 OW to 100 KW may be applied, and either an internal electrode or an external electrode (electrode) may be used.

The molded body is treated with low 7h^ plasma generated under the above-mentioned conditions, and a plasma polymerized film of an organic compound is formed on the surface of the body. Generally speaking, a few seconds to about No. 100 is sufficient, although this may vary depending on the situation.

Next, specific examples will be given. Each of the oxygen permeability coefficients and nitrogen permeability coefficients in each of the following examples, JIS
The measurement was conducted based on a method similar to Z 1707 (decompression method), in which the membrane was first held in a permeation cell, the space on both sides of the membrane was evacuated using a vacuum pump, and then oxygen or oxygen was added at atmospheric pressure. It was calculated by measuring the pressure change per unit time on the side where nitrogen was introduced and passed through the membrane.

Example 1 Silicone rubber reit (silicone rubber KE manufactured by Shin-Etsu Chemical Co., Ltd.) with a thickness of 50 nol TL obtained by a calender molding method.
-1517 was set in a plasma generator, and the pressure inside the device was reduced to IO"-4 torr. Then, vapor of trimethylvinylsilane as a Tfa monomer was introduced into the device, and the pressure was adjusted and maintained at 0.2 torr under circulation. Nora, 13.56
A low-temperature plasma of trimethylvinylsilane was generated by applying high-frequency power of MHz 150W for 12 minutes.
A plasma polymerized film was formed on the sheet.

Oxygen permeability coefficient, nitrogen permeability coefficient and separation rate (
When the oxygen permeability coefficient/nitrogen permeability coefficient) was measured, the results were as shown in Table 1 below.

In addition, as a comparative example, samples that were not subjected to plasma polymerization treatment are also listed in the same table.

Table 1 (Note) c4-tyn/ctlr・sea・cm
Hg Example 2 A plasma polymerized film was formed on a silicone rubber sheet in the same manner as in Example 1 except that rollosilane of trimethylvinylsilane and dimethyldimethoxysilane were used. When these physical properties were measured, they were as shown in Table 2 below.

Table 2 Example 3 t/l of Q cone KE45RTV (Shin-Etsu Chemical brand name)
When the luene solution (071 fft%) was cast on a polyethylene plate and cured, a 35 μm silicone rubber sheet was obtained.

This sheet was set in the apparatus of Example 1, and the pressure inside the apparatus was reduced to 10 Torr. Then, trivinylmethylsilane vapor was introduced into the apparatus, and the pressure was adjusted and maintained at 0.3 Torr while circulating. Then, high-frequency power of 11 kHz and 500 W was applied for 3 minutes to generate low-temperature plasma of trivinylmethylsilane, and the sheet was processed to form a plasma polymerized film. The physical properties of this product were measured and were as shown in Table 3 below.

Table 3 Example 4 A solution was prepared by dissolving 1 g of polycarport fill in 12,000 g of toluene and SO AA of dimethylformamide, and the solution was dropped onto the water surface to form an extremely thin film. This ultra-thin film was scooped onto a piece of paper and dried at room temperature for one day and then at 80° C. for 3 hours.

The ultrathin polycarbonate film obtained as described above was subjected to the same plasma polymerization treatment as in Example 1 in the apparatus of Example 1 to form a plasma polymerized film.

The physical properties of this product were measured and found to be as shown in the fourth column below. In addition, when the ultra-thin polycarbonate film was measured by a gravimetric method, the film thickness was 0.98 μm.

Table 4 Example 5 A porous glass plate with a pore diameter of 200X was used as an inorganic porous material (
(manufactured by Cornyn Douglas Corporation) was set in the apparatus in [Example], the pressure inside the apparatus was reduced to 10''-' Torr, and trivinylmethylsilane vapor was introduced into the apparatus and the pressure was reduced to 0.3 Torr under circulation. Adjusted and held at 110KH in this state.
A low-temperature plasma of trivinylmethylsilane was generated by applying high frequency power of 500 W for 40 minutes to generate plasma on the porous glass plate to form a plasma polymerized film on the porous glass plate. The physical properties of this product were measured and were as shown in Table 5 below.

Claims (1)

[Claims] 1. The oxygen permeability coefficient in the gas permeable part made of an organic polymer material or an inorganic porous material is 8 1 × 10 crl-cm/-・sec ・mH
A composite molded article for gas separation having a separation coefficient of 2.5 or more, which is obtained by providing a low-temperature plasma polymerized membrane of an organic compound on a molded article having a separation coefficient of 2.5 or more. 2. The composite molded article for gas separation according to claim 1, wherein the low temperature plasma polymerized membrane has a thickness of 0.01 to 1 μm. 3. The composite molded article for gas separation according to claim 1, wherein the organic compound is an organosilicon compound. 4. A composite molded body for gas separation in which an organic compound has an unsaturated bond in its molecule. 5. The composite acid fluoride for gas separation according to claim 1, which is used to obtain oxygen-enriched air from air.