JPS5953539A - Manufacture of ultrathin film - Google Patents

Abstract

PURPOSE:To obtain an uniform ultrathin film of high gas permeability with highly selective separability, by casting on water surface a solution prepared by dissolving a polymer in a nonaqueous organic solvent incorporated with a sulfactant consisting mainly of organosiloxane. CONSTITUTION:A polymer such as condensed-type one (e.g., polyphenylene ether), polyurethane, polyolefin, is dissolved in a nonaqueous organic solvent (e.g., benzene, methyl acetate, chloroform) incorporated with 1-10wt% of a surfactant consisting mainly of organosiloxane, e.g., a copolymer from polyhydroxystyrene or phenolic resin and a terminal-reactive polydimethyl siloxane. The resulting solution is cast on water surface to form the objective ultrathin film on it.

Description

[Detailed description of the invention] Industrial applications The present invention t'2. Mixed fluid, ribs against mixed gas.

The present invention relates to a method for producing an ultra-thin polymer membrane having permselectivity.

Structures of conventional examples and their problems In recent years, there has been remarkable progress in separation technology using membranes, and some of them have actually been put into practical use on an industrial scale. However, things that have not been put into practical use include desalination of seawater, treatment of factory wastewater, and concentration of food products.
Liquid-liquid separation or liquid-membrane separation, gas-temperature,
That is, the separation of two or more types of mixed gases has hardly been put into practical use.

The reason why membrane separation of gases cannot be easily put into practical use is that the selective permselectivity is relatively low.In other words, there is no membrane that selectively passes certain gases and almost no other gases. In order to obtain gas, it is necessary to adopt a multi-stage method in which membrane separation is repeated several times, which results in the equipment being too large, and because the amount of permeation is small, it is impossible to produce a large amount of gas. etc. 0
From the point of view of selective permselectivity, there are many fields in which gases of high purity are not necessarily required for their final use. For example, in the case of oxygen, it is used for blast furnace ventilation.

High-purity oxygen is not necessarily required for combustion auxiliary use 1 for petroleum protein processes, for waste liquid sewage treatment, and for medical purposes such as exhalation. Not only that, but high-purity oxygen has many disadvantages, such as damage to the furnace, danger of fire, and blindness in premature infants. Conventionally, as a method for obtaining oxygen-enriched air for use in the above-mentioned applications, high-purity oxygen is produced using an air separation device (air liquefaction method) 7 and then mixed with air to achieve the desired oxygen concentration.

However, (2. In such methods, high-purity oxygen is generally contained in a pressure vessel, so the dangers of handling the pressure vessel,
Or is it impossible to keep the mixed gas concentration constant? J!
There are many problems such as the indispensability of the 1flii reactor and the top layer nature of its operation.Therefore, as a method of obtaining oxygen-enriched air of low purity or intermediate level J9, air separation by membrane separation is a better way to obtain oxygen-enriched air directly from the atmosphere. Oxygen-enriched air can be obtained from air, and it is operationally simple and economically advantageous.

Conventionally, two methods are known for producing oxygen-enriched air using membrane thickening [1]. One is a method using hollow fibers such as polyethylene, polystyrene, or polyethylene terephthalate.

(Japanese Unexamined Patent Publication No. 49-10192, Japanese Patent Publication No. 49-812
(Refer to Publication No. 98) The other is organoborisiloxa 7
- A method using an ultra-thin film such as a polycarbo-inert copolymer,
(U.S. W. No. 3980456, No. 3874986
Please refer to the details of the issue).

The method using hollow fibers increases the permeation amount by increasing the membrane area per unit area, but it is still too large and simple to obtain a practical permeation amount of 1-. On the other hand, ultra-thin membranes increase the amount of permeation by taking advantage of the fact that the amount of permeation is inversely proportional to the membrane thickness. The thing is.

This is based on the fact that when gold gas passes through a uniform membrane, the amount is generally expressed as:

F: permeation flow rate (owl/sec) β; gas permeability coefficient (cljI-tyn/(ka5ec-o+Hg)△P1
Pressure difference (αHg) A: Membrane area (cl) L: Membrane thickness (n〃) In the above formula, A and ΔP depend on external equipment necessary for gas separation and have certain limits. In addition, since the furnace is constant depending on the usage, in order to increase the permeation flow rate F, it is necessary to ultimately make i as large as possible and the film thickness as thin as possible. One example of a thin film is a film made of an organoborisiloxane-polycarbonate copolymer.The film thickness of this copolymer is 0.
．． The material itself has an oxygen permeability coefficient of -1o (cc -ctn/l: A asec
-onHg), oxygen separation coefficient (PO27pN, )
It has a good rating of 2.0-2.4, but it has poor chemical resistance and there is a risk of deterioration due to contaminated air or oil from oil-filled pumps or comb sothers used for depressurization and pressurization, and deterioration due to hydrolysis. This is conceivable and has problems in practice. An even bigger problem is that in order to produce an ultra-thin film of this organoboridimethylsiloxane-polycarbonate-1 copolymer, it is necessary to use the solvent for this polymer and I~, which has a high specific gravity (1,2.3-) It is necessary to use liquid propane, trichlorethylene, chloroporm, etc., and drop this polymer solution onto the water surface to form an ultra-thin film! I
When a polymer solution is used, a portion of the polymer solution settles below the water surface and cannot spread sufficiently spontaneously, making it difficult to easily produce a uniform thin film for practical use. Other ultra-thin film manufacturing methods include Japanese Patent Application Laid-Open No. 56-166232.
There is one shown in Japanese Patent Application Laid-Open No. 66-92925. These methods involve adding a compound such as an alcohol having a hydrophilic group to a cyclohexene solution of a hydrophobic polymer such as a polyolefin or diene polymer, or adding a mixture mainly composed of partially oxidized cyclohexene to a solution of hydrophobic polymers such as polyolefins or diene polymers in cyclohexene. By using it as a solvent for the polymer, it was devised so that it would spread spontaneously and uniformly on the water surface. however.

Although these methods are effective for polyolefins and diene polymers, the disadvantage is that they cannot be applied to other polymers.

Purpose of the Invention The present invention has been made to solve the following problems in the conventional art. 1] The purpose is to provide a method for producing a uniform ultra-thin film that can be used for.

Structure of the Invention In order to achieve the -4 objective, the present invention uses a silicone-based hydrophobic solution of a polymer for thin film production, which is difficult to spread on the water surface and is non-uniform, making it difficult to form a thin film. By adding a surfactant (C-1 to C-10 by weight, it is possible to achieve polymer spreading, uniformity, and ultra-thin film formation.) /
, toluene, xylene, chlorobenzene, ethyl acetate,
Methyl acetate, chloroform, methylene chloride, li [IC1
0 year old with eta/l chloropropane, etc. IJ: IF
-7 series surfactant: % opening/closing 66-26606
A copolymer of polyhydroxystyrene and terminal-reactive polydimethylsiloxane shown in JP-A No. 66-24019
By adding the copolymer of phenol resin and terminal-reactive polydimethylsiloxane shown in No. 1, as well as other surfactants mainly composed of silicone, an extremely good ultra-thin film can be produced. : It's a good deal.

DESCRIPTION OF EXAMPLES The present invention will be described in more detail below with examples mainly based on the experiments conducted so far, but the examples are only for explaining the present invention and are not limited thereto. isn't it.

Comparative Example 1 Polyphenylene oxide (PPO) with a weight average molecular weight of approximately 100,000 was dissolved in toluene and adjusted to a solution of 2 parts by weight (
/child. Using this solution, we investigated the creation of an ultra-thin film on the water surface using the Langmuir method, but with this solution composition,
PPO did not diffuse uniformly on the water surface, and it was not possible to form a thin film.

<Example 1> When 1 CC of the IQwt% benzene solution of the copolymer of polyhydroxystyrene and polydimethylsiloxane shown in JP-A-66-26606 was added to the solution shown in Comparative Example 1, the ppo was uniformly increased. Diffused on the water surface, s o
A uniform ultra-thin film was deposited over an area of arr x s ocm. The volume of the droplet at this time is 0.06 CC, and the weight of PPO contained in the droplet is 2.09 x 101. From this, calculate the film thickness by setting the specific gravity of PPO to 1, ○. Then it becomes about 0.1μ.

A copolymer of polyhydroxystyrene and polydimethylsiloxane was found to be a very effective additive in the production of ultra-thin films. As in Comparative Example 1, attempts were made to form an ultra-thin film on the water surface, but the results were not good. Therefore, when a benzene solution of a copolymer of polyhydroxystyrene and polydimethylsiloxane was added in the same manner as in Example 1, this time it immediately spread on the water surface, resulting in a uniform ultra-thin film. The membrane thus obtained was coated with porous polypropylene (Duragart 2).
As a result of measuring the properties of the film, the film thickness was approximately 0.1 μm and the 5-separation coefficient (PO2/PN2) was 4.0.

<Example 3> A silicone-based H3 copolymer containing polyhuman[1-xystyrene was made into a 2% by weight solution of benzene, and then this was
It was attempted to diffuse onto the water surface -1-, but it took a considerable amount of time to diffuse, and the spread was small and non-uniform. Therefore, in the same way as in Example 1, a 4-weight benzene solution of PH8-P DMS copolymer was added at a concentration of about 1°, and the O droplets were diffused on the water surface under the same conditions. The O droplets quickly spread and formed a uniform ultra-thin film. The thickness of the O film obtained was approximately 0.1 μ, and the separation coefficient (PO2/PN2) was 2.1, which was 0. Example 4 As in Example 3, this time novolak was included as the polymer. A study was conducted on silicone-based H3 copolymers.

Again, by adding a 4 weight ratio benzene solution of PH3-PDMS, it was possible to produce a uniform ultra-thin film.The zero film thickness was approximately 0.2μ, and the separation coefficient (PO2/PN2) was 2.2.
Tea Tsuta.

<Example 6> As in Example 1, PP0i was used as the polymer for thin film production, and Toray Silicone SH3748 (trade name)'! I-, and add about 1% of this to 100ml of the above polymer solution.
When ml was added, the spread on the water surface at this time was as shown in Example 2.
As in the case of , it was very good. 0.05CC, it spread in about 60 (7) square directions, and the equivalent film thickness was 0.08μ □ <Example 6> Similarly to Example 1, polyurethane (as shown in MW-・60,000), and double 1
i (% be/zene solution 0 without adding surfactant 1
As in the case of PPO, a uniform thin film was not formed on the water surface, but Toray Silicone 5 was used as a surfactant.
Using H3530 (trade name), add it to a polymer solution of 100%
Approximately 2 ml was added to πt (as a result, its spreading on the water surface was significantly improved, forming a uniform ultra-thin film over an area of approximately s o +:I. The equivalent film thickness was approximately 0
．． In Examples 1 to 6, typical polymers for producing ultra-thin films were mainly used, and appropriate ricone-based surfactants were used accordingly. Therefore, in the present explanation, we will cover all of them. 1) Surfactants used in the present invention It can be easily assumed that the same effect can be obtained even if λ"1 is used for polymers other than the ξ-condensed, vinyl-based, and silicone-based polymers shown here.

DETAILED DESCRIPTION OF THE INVENTION Thus, the present invention creates an ultra-thin polymer film by adding 1 to 20 units of a surfactant containing organosiloxane as a main component to a hydrophobic polymer solution. J+J ability is to manufacture easily and uniformly. Q'4j: Unlike conventional methods, this method can be applied to all hydrophobic polymers, and in this case, there is no need to change the solvent for each polymer, and it is possible to create ultra-thin polymer films. It is a very effective means for manufacturing.

Name of agent: Patent attorney Toshio Nakao and 1 other person33
7-

Claims (10)

[Claims] (1) Using a mixture of a surfactant containing organosiloxane as a main component and a non-aqueous organic solvent as a solvent, a solution in which a polymer is dissolved in this is diffused onto the water surface, and the polymer is superimposed on the water surface. A method for producing an ultra-thin film, characterized by forming a thin film. (2) The method for producing an ultra-thin film according to claim 1, wherein the surfactant contains silicone as a main component. (3) The method for producing an ultra-thin film according to claim 1, wherein the surfactant is a silicone copolymer synthesized from polyhydroxystyrene-terminated reactive polydimethylsiloxane. (4) The method for producing an ultra-thin film according to claim 1, wherein the surfactant is a silicone copolymer synthesized from a phenol resin and a terminally reactive polydimethylsiloxane. (5) Non-aqueous organic solvents include benzene, toluene, xylene, chlorobenzene, ethyl acetate, lXI+acid, etc.
Method 0 for producing an ultra-thin film according to claim 1, which is at least one selected from the group consisting of chloroform, methylene chloride, chloroethane, chloropropane, and carbon tetrachloride. (6) The ultra-thin film described in item 1 of the scope of claims of the patent 'RWI, wherein the polymer is at least one selected from the group consisting of a mesh type polymer, polyurethane, polyolefin, diene polymer, and silicone copolymer. Manufacturing method〇 (7) The general formula of the mesh type polymer is: (However, m is an integer of 1 or 2, and X is a hydrogen atom. It is selected from the group consisting of a methyl group, an ethyl group, a halogen atom, a sulfonic acid group, and a nitro group.) The method for producing an ultra-thin film according to item 6. (8) Polyurethane has a general formula. +GH2-)-, selected from the group consisting of. ) The method for producing an ultra-thin film according to claim 6, which is a polyurethane represented by (9) The polyolefin and diene polymer is at least one selected from the group consisting of polybutene, polybentene, polymethylpentene, polyhexene, polymethylhexene, polybutadiene, and polyisoprene. Method for manufacturing ultra-thin films. (10) The silicone copolymer is a block copolymer or a graft copolymer with polyorganosiloxane. A method for producing an ultra-thin film according to claim 6.