JPH03284333A - Liquid separating material and separation of liquid - Google Patents

Abstract

PURPOSE:To selectively separate water, alcohol, chlorohydrocarbon, etc., by using a polyamide grafted with an alkylene oxide as a liq. separating material. CONSTITUTION:Polyamide such as 6-nylon is allowed to react with 1,2-alkylene oxide such as ethylene oxide to obtain a polyamide grafted with an alkylene oxide as a polyamide-based new liq. separating material. This grafted polyamide is formed into a membrane and used as a separating membrane or packed into a vessel in the form of powder, granules, sheets, fibers, etc., and used as an absorption separating material. The separating membrane is selectively permeable to water, alcohol, chlorohydrocarbon and amines. The absorption separating material selectively absorbs the same substances.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to a liquid separation material using alkylene oxide grafted polyamide, and also relates to a liquid separation material using alkylene oxide grafted polyamide, and also relates to a liquid separation material containing water, alcohol, chlorinated hydrocarbons, and amines. Concerning methods of separating objects.

[Conventional technology]

Various polymer membranes have been proposed as functional membranes in the past, and they have been used in the conventional chemical industry for distillation, which requires a large amount of energy.
The application of polymer membranes to liquid mixture separation technology is becoming more and more popular, such as applying membrane separation instead of rectification, liquid-liquid separation in the biotechnology field, and application in the medical field. is also expanding.

[Problem to be solved by the invention]

However, the permselectivity of polymer membranes is specific;
Various membranes are used depending on the field of application, and various polymer membrane technologies are still in the development stage.

The inventors have studied the functionality of alkylene oxide graft polyamides, which have conventionally been made for the purpose of modifying nylon, and have found that they have liquid-liquid separation ability, leading to the present invention.

Alkylene oxide graft polyamide is a combination of polyamide and C2-1 1, such as ethylene oxide, 1,2-propylene oxide, 1,2-butylene oxide, etc.
It can be obtained by grafting reaction with 2-alkylene oxide, and is already known, for example, in JP-A No. 47-897.

These alkylene oxide graft polyamides are made for the purpose of modifying nylon as mentioned above, and are mainly used to improve the hydrophilicity, antistatic properties, etc. of polyamides, and refer to the functional aspect of liquid separation of liquid mixtures. There is nothing I did.

The present invention focuses on the liquid-liquid separation functionality of the alkylene oxide grafted polyamide, and aims to provide a new polyamide-based liquid separation material.
An object of the present invention is to provide a liquid separation method using a liquid separation material that selectively separates alcohol, chlorinated hydrocarbons, and amines from a liquid mixture containing these substances.

[Means to solve the problem]

According to the present invention, there is provided a liquid separation material characterized by being made of alkylene oxide graft polyamide.

Furthermore, the method is characterized in that a liquid separation material made of alkylene oxide grafted polyamide is used to separate the compound contained in the liquid mixture containing at least one of water, alcohol, chlorinated hydrocarbon, and amines. A liquid separation method is provided.

The present invention will be explained in more detail below.

The alkylene oxide graft polyamide (hereinafter referred to simply as graft polyamide) used in the present invention is a combination of polyamide and 02-4 1,2-alkylene such as ethylene oxide, 1,2-propylene oxide, 1,2-butylene oxide, etc. It can be obtained by reacting with oxide. Polyamides include nylon 6, nylon 6B, nylon 610, nylon 11, and nylon 612.
Typical nylons such as nylon can be used.

The graft polyamide of the present invention has 1.2-
It may be obtained using any known method of grafting alkylene oxides. Usually, the above-mentioned nylon powder or pellets or film-like nylon and the above-mentioned alkylene oxide are used in a molar ratio of about 1:0.5 to 10, and in an autoclave without a catalyst and under an inert gas atmosphere such as nitrogen, about It can be obtained by maintaining the temperature at 100°C or lower for a predetermined time to remove unreacted substances and alkylene oxide homopolymer.

In this case, the graft polyamide obtained by the method described in JP-A-47-897 is water-soluble and is therefore undesirable for use as a separation material due to limitations.

The 1,2-alkylene oxide grafting rate of the graft polyamide used in the present invention is not particularly limited, but the liquid permeability usually increases as the grafting rate increases, so it is selected as appropriate depending on the desired separation rate and separation conditions. It can be used as

- For boat fishing, it is preferable to use a grafted polyamide with a graft ratio of about 30% or more, preferably about 50% or more.

The graft polyamide obtained as described above is mainly obtained by reacting and polymerizing 1,2-alkylene oxide with the amide group of polyamide, and grafting a polymer of alkylene oxide.

The liquid separation material of the present invention can be used as an absorption separation material by being filled into a container in the form of a membrane-like separation membrane or in the form of a powder, granules, sheet, fiber, or the like.

When used as a separation membrane, the liquid separation membrane is a thin film made of the above-mentioned grafted polyamide, and the grafted polyamide obtained by grafting it onto a normal powdered or pelleted polyamide is mixed with a suitable solvent such as formic acid, sulfuric acid, or trifluoroethanol. , tetrafluoropropanol, hexafluoroisopropanol, or the like, forming a thin film from the solution, removing the solvent, and solidifying to form a homogeneous film. In this case, the film is formed using a substrate with a smooth surface, such as a glass plate, a copper plate, a metal roll, or a heald, as the base material used for manufacturing the homogeneous film, and after the film is formed, the film is peeled off from the base material. By doing so, an extremely thin film can be obtained. Further, the graft polyamide may be melted and made into a film using an inflation molding method or a T-die molding method, or a film obtained by further stretching the molded film may be used.

This thin film-like homogeneous membrane can be used as it is as a liquid separation membrane, or can be used by laminating or bonding with other porous membranes. Furthermore, by using a porous membrane as a base material for forming a homogeneous membrane, it is also possible to obtain a composite liquid separation membrane integrally formed on the surface of the porous membrane.

Furthermore, in the present invention, a polyamide film is formed in advance by a known method, and the polyamide film is directly coated with a polyamide film.
, 2-alkylene oxide can also be grafted. When using a polyamide film formed in advance by grafting, the grafted polyamide film obtained by grafting 1,2-alkylene oxide onto an unstretched film is free from water, alcohol such as methanol, and chlorinated hydrocarbons than the grafted film of the stretched film. and amines, making it more suitable for separating liquid mixtures containing them.

The liquid separation material of the present invention can be formed into various structures by forming the graft polyamide into a flat membrane shape or a hollow fiber shape,
It can be used as a liquid filtration membrane, ie, a liquid separation membrane, for ordinary filtration, precision filtration, ultrafiltration, reverse osmosis, etc., which separates by ordinary pressure difference.

In the present invention, the thickness of the homogeneous graft polyamide layer forming the liquid separation membrane is not particularly limited, but is usually 0.
．． It is used in a thickness of 1 to 500 μm.

The graft polyamide liquid separation membrane of the present invention selectively permeates water, alcohol, chlorinated hydrocarbons, and amines,
Especially water, methanol, methylene chloride, chloroform,
Dichloroethane, trichloroethane, tetrachloroethane, pentachloroethane, hexamethylenediamine, aniline, N-methylaniline, N-ethylaniline, 0
- It has particularly high permeability for methylaniline, m-methylaniline, 0-chloroaniline, m-chloroaniline, and pyridine, and can be suitably used for separation, purification, concentration, etc. of liquids containing these. For example, when chlorinated hydrocarbons such as methylene chloride are used as a solvent in extraction or reaction, they can be effectively used for separation and removal.

The liquid separation of the present invention can be applied to any of the filtration separations using pressure differences as described above, but it can be particularly preferably used for ultrafiltration, pervaporation, etc. In these liquid separations, preferably 0 to 150°C1, particularly preferably 10~
Preferably, the reaction is carried out at 100 DEG C. and under a pressure of about 0.1 to 100 kg/cm@2, particularly preferably about 0.5 to 80 kg/cm".

The graft polyamide of the present invention can be effectively used for liquid separation using a membrane as described above, and also has excellent absorption ability for water, alcohol, chlorinated hydrocarbons, and amines such as aniline, and can be used for absorption and separation of water, alcohol, chlorinated hydrocarbons, and amines such as aniline. It can also be used as a material.

In this case, as described above, it is preferable to use the graft polyamide of the present invention in the form of a powder, granules, sheet, fiber, etc. as an absorption/separation material, and the shape, size, etc. thereof are not particularly limited. Generally, particles having an average particle diameter of 0.01 to 5 m are used. In order to absorb and separate a liquid-containing substance from a liquid mixture, as described above, a container such as a column is filled with the above-mentioned material, and while the liquid mixture is flowing, a predetermined liquid-containing substance such as water is absorbed. It may also be separated. Alternatively, the above-mentioned shaped article can be immersed in a liquid mixture or the like, and predetermined liquid-containing substances can be absorbed and separated and removed.

The graft polyamide of the present invention has a unique phenomenon particularly in the absorption of water. For example, when a graft polyamide with a graft ratio of 81.8% is used to absorb water, the equilibrium water absorption water absorption rate) is 5
Approximately 200% at °C, approximately 145% at 20°C, 100°C
The equilibrium water absorption rate is approximately 112% at low temperatures, and G1 decreases as the temperature increases. In addition, this phenomenon does not change even if the temperature is repeatedly changed from 5°C to 100°C and from 100°C to 5°C. Release can be repeated with good reproducibility, and it can be used as a water absorbing material to repeatedly absorb and regenerate.

〔Example〕

Examples of the present invention will be described in detail below. However, the present invention is not limited to the following examples.

In addition, in the present invention, the total polymerization rate (%), graft polymerization rate (%), homopolymerization rate (%), weight increase rate (%), grafting rate (%), and grafting efficiency (%) are expressed by the following formulas. This is the value calculated by

However, in each formula below, the amount of polyamide charged in the reaction is W
i, the amount of alkylene oxide is Q, the solid weight after removing unreacted alkylene oxide after reaction is W2
The solid material was washed with hot water to remove the homopolymer of alkylene oxide, and the weight of the hot water insoluble matter was defined as Wf.

Example 1 (Manufacture of liquid separation material) 20 g of unstretched film AO made of nylon 6 with a thickness of 50 μm (manufactured by Ube Industries ■, trade name: UBE1022B) and ethylene oxide (manufactured by Nippon Shokubai Chemical Industry ■) 4 (ld) were combined. The mixture was placed in a stainless steel autoclave and reacted without a catalyst at 80°C under a nitrogen gas atmosphere for a predetermined time. After the reaction, unreacted ethylene oxide was removed by evaporation, and the mixture was placed in boiling water for 1 hour while replacing the boiling water. It was washed for a total of 4 hours.

Thereafter, it was vacuum dried at 50°C for 72 hours to obtain a grafted polyamide film.

As a result, a grafted polyamide film AIAs having a graft ratio as shown in Table 1 was obtained.

In addition, in place of the above-mentioned unstretched film A0, a two-wheeled stretched film B0 made of nylon 6 and having a thickness of 25 μm (manufactured by Kojin ■, trade name: Bonyl) was used, and the graft reaction was carried out in exactly the same manner. As a result, grafted polyamide films B and -B with graft ratios shown in Table 1 were obtained.

(Hereinafter, blank space) Example 2 Grafting rate obtained in Example 1: 116.7%, thickness: approximately 6
A graft polyamide film A4 of 2 to 67 μm and a graft polyamide film B4 of 98.6% grafting rate and a thickness of about 29 to 34 μm were attached to an RO-3 type reverse osmosis/ultrafiltration tester (manufactured by Bio Engineering ■). Add 150 ml of each solvent, permeation area 31.2 cat, pressure 20 kg/cii! The amount of permeation after treatment at room temperature for 3 hours was measured.

The results are shown in Table 2.

(Hereinafter, blank space) Table Comparative Example The amount of permeation was measured in the same manner as in Example 2 using an unstretched polyamide film A0 that was not grafted.

As a result, the permeation amount was Od in all cases.

Example 3 Using nylon 6 powder (manufactured by Ube Industries, trade name: UBE1022B) with an average particle size of 0.2 am, a reaction was carried out for 6 hours in the same manner as in Example 1, resulting in a grafting rate of 81.8%. A powder graft polyamide was obtained. The obtained powder graft polyamide was filled into a 2-inch-thick slider, sandwiched between aluminum plates, and hot press-molded. The aluminum plate and spacer were coated with silicone KS700 (manufactured by Shin-Etsu Chemical Co., Ltd.), and the temperature was 230°C and the pressure was 100 kg/ci.
It was hot pressed for 3 minutes (including 1 minute of preheating time).

After hot pressing, it was cooled by sandwiching it between 20 mm thick stainless steel plates at room temperature, and then vacuum dried at 50° C. for 1 day. A test piece of 25 x 25 x 2 mm was cut from the obtained molded piece and subjected to a water absorption test.

Two test pieces each were immersed in water in an electronic thermostatic water bath ECW-6WEN model (manufactured by Tajiri Kikai Kogyo ■) or an oil bath at 5°C12O°C1100°C. Ion-exchanged water was used as water. The water absorption rate was calculated by tracking the weight change. As a result, the equilibrium water absorption rate was 200% at 5°C, 2
0°C? 145%, and 112% at 100°C.

In addition, a water absorption cycle test was conducted in which the specimen was repeatedly immersed in water at 5°C and hot water at lOO"C, and the relationship between water absorption rate and time is shown in Figure 1. It can be seen from the change in water absorption that the graft polyamide apparently absorbs and releases water.

[Effects of the Invention] The liquid separation material of the present invention has 12-
This product uses grafted polyamide grafted with alkylene oxide, and has excellent absorption and permeability for water, alcohol, chlorinated hydrocarbons, and amines, and can permeate or absorb these substances or other components from liquid mixtures containing them. In particular, chlorinated hydrocarbons are extremely useful industrially because they are used in large quantities as various solvents.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the relationship between water absorption rate and time in a water absorption cycle test in which the temperature of the grafted polyamide liquid separation material of the present invention was varied.

Claims (2)

[Claims] (1) A liquid separation material characterized by being made of alkylene oxide grafted polyamide. (2) A liquid separation material made of alkylene oxide grafted polyamide is used to separate the compound contained in the liquid mixture containing at least one of water, alcohol, chlorinated hydrocarbon, and amines. Liquid separation method.