JPS62140603A - Liquid separation membrane - Google Patents

Abstract

PURPOSE:To obtain the titled liq. separation membrane having a high separation factor, a high permeation flow rate, and an excellent membrane-forming property in a permeation vaporizing method by using a substituted acetylene polymer having a specified silyl group. CONSTITUTION:For example, a catalyst of tantalim, etc., is added to a soln. of 1-(tridecafluoro-1,1,2,2-tetrahydrooctyl)dimethylsilyl-1-pr-opyne in toluene, polymerization is carried out, and a polymer contg. a repeating unit shown by the formula is obtained. The polymer is dissolved in 1,1,2-trichloro- trifluoroethane, etc., to prepare a casting soln. The soln. is cast over a glass sheet, and the solvent is vaporized to obtain a filmy membrane. The membrane thus obtained has an excellent performance is separating a liq. mixture of water-ethanol, etc., by a permeation vaporizing method.

Description

[Detailed description of the invention] [Technical field] The present invention relates to a novel liquid separation membrane.

More specifically, the present invention relates to a separation membrane for mixed liquids.

[Prior Art and its Problems] Conventionally, distillation has been commonly used to separate mixed liquids. However, distillation requires a large amount of energy and has problems in that it is difficult to separate azeotropic mixtures, substances with similar boiling points, and substances that are unstable to heat. In recent years, separation methods using membranes have been researched and developed, and their future development as an energy-saving separation method is expected.

Separation methods using membranes include permeation vaporization, reverse osmosis, and dialysis, depending on the separation factor and separation operation.Reverse osmosis and dialysis can be used to desalinate seawater, brine, produce ultrapure water, treat waste liquid, etc. Some have already been put into practical use in fields such as water treatment, the food industry, and medicine. Among the separation methods using membranes, the pervaporation method is used to separate the mixed liquid by placing the mixed liquid to be separated on one side of the membrane and applying reduced pressure to the other side or flowing a gas inert to the mixed liquid components. Among them, this is a method of selectively transmitting the negative component. This separation method is not affected by osmotic pressure and can be used in a wide range of applications as it is capable of separating mixed solutions over a wide range of concentrations.

Liquid separation by pervaporation method is disclosed in Japanese Patent Application Laid-Open No. 59-203610.
No. 59-203607, No. 59-203
No. 602 and No. 59-4402 use sulfonated ethylene copolymers, and No. 58-84005 and No. 58-89901 use fluorine-containing polymers having acid type functional groups, respectively. I am doing it.

However, the reason why the pervaporation method has not yet been put into practical use is due to problems with the membrane's separation coefficient, permeation flow rate, and membrane formability.

On the other hand, the separation of liquid mixtures is of great industrial significance, and
Water-ethanol separation is attracting attention from the standpoint of concentrating 1 q of ethanol from biomass as an alternative energy source to petroleum.

As a result of intensive research on ω1 using various materials, the present inventors discovered that a separation membrane made of a substituted acetylene polymer having a specific silyl group has excellent performance in liquid separation. This led to the present invention.

[Means for Solving the Problems] In order to achieve the above object, the present invention consists of the following +M components.

[General formula [In the formula, R1 is a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, or an alkynyl group, R2R3,
R4 is aromatic, substituted aromatic, alkyl group, alkenyl group, aromatic substituted alkyl group, or C++ -[(C)(co)-8i]-C++ -〇HI (m and n are integers of 1 to 6) and these R1-R4
A liquid separation membrane comprising as a main component a polymer containing as a repeating unit at least one of which is substituted with at least one hydrogen or halogen atom. ” In the present invention, in the general formula (I), the alkyl group, alkenyl group or alkynyl group of R1 is a methyl group,
Ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, ocdyl group, nonyl group, decyl group,
Allyl group, butenyl group, pentenyl group, acetylene group, etc. are required.

Aromatic groups of R2, R3, and Ra include phenyl group, naphdyl group, substituted aromatic group include methylphenyl group, dimethylphenyl group, trimethylphenyl group, and alkyl group and alkenyl group include methyl group, ethyl group, propyl group, butyl group. groups, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, allyl group, butenyl group, pentenyl group, and aromatic group-headed alkyl groups such as benzyl group, phenylethyl group, phenylpropyl group, phenylbutyl group. base, phenylpentyl group, phenylhexyl group, etc.

-[(0 day 2> m -3i CC day!>
2 ] n -CH3 (m, n is an integer of 1 to 6) As a substituent, a trimethylsilylmethyl group, a trimethylsilylmethyldimethyldimethylsilylmethyl group,
Examples include trimethylsilylethyl group, trimethylsilylethyldimethylsilylethyl group, and the like. Furthermore, examples of these substituents in which at least one hydrogen is replaced with a halogen atom include a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a chloromethyl group, a dichloromethyl group, a trichloromethyl group, a bromomethyl group,
Dibromomethyl group, tribromomethyl group, fluoroethyl group, difluoroethyl group, trifluoroethyl group, perfluoroethyl group, chloroethyl group, bromoethyl group, fluoropropyl group, difluoropropyl group, trifluoropropyl group, tetrafluoropropyl group , pentafluoropropyl group, hexafluoropropyl group, perfluoropropyl group, chloropropyl group, bromopropyl group, fluorobutyl group, trifluorobutyl group, perfluorobutyl group, thalolobutyl group, bromobutyl group,
Fluorohexyl group, trifluorohexyl group, heptafluorohexyl group, perfluorohexyl group, chlorohexyl group, bromohexyl group, fluorophenyl group,
trifluorobutyl group, heptafluorooctyl group, tridecafluorooctyl group, perfluorooctyl group,
chlorooctyl group, promoocdyl group, fluorophenyl group, difluorophenyl group, trifluorobutyl group,
Examples include perfluorophenyl group, chlorophenyl group, bromophenyl group, 1-lifluoromethylphenyl group, chloromethylphenyl group, and bromomethylphenyl group.

In general, the polymer of the present invention is a homopolymer or copolymer having the above-mentioned substituents, and these polymers can be used alone or in a blend with each other. Alternatively, Haku's seven polymers may be copolymerized with the above-mentioned repeating unit, or Haku's polymer may be blended within a range that does not impair the present invention.

The method for obtaining the polymer according to the present invention is disclosed in Japanese Patent Publication No. 51-37312, Japanese Patent Publication No. 52-20511,
No. 54-43037, No. 55-23565, No. 55-30722, JP-A-57-31911
@ Publication, Publication No. 57-36106, Publication No. 58-3260
Publication No. 8, Publication No. 59-78218, Publication No. 59-197
Examples include the method disclosed in Japanese Patent No. 410. Specifically, each substituted acetylene heptamine is treated using a tungsten-based, molybdenum-based, tantalum-based, or niobium-based catalyst, and if necessary, an organic total bending compound such as tin, silicon, bismuth, or aluminum. It is obtained by polymerizing a hydrocarbon or a halogenated hydrocarbon as a solvent by using it as a cocatalyst.

The molecular weight of these polymers used in the present invention was determined by GPC (
The number average molecular weight of polystyrene (gel permeation chromatography) is 10,000 or more, preferably 10,000 to 5,000,000, particularly 20,000 to 1,000,000. If the number average molecular weight is less than 10,000, film forming properties are poor.

The polymer used in the present invention is generally dissolved in a solvent and cast onto a suitable surface such as a glass plate or a Teflon plate, then the solvent is evaporated to form a film, and the film is peeled off by any means. can be done. or,
In general, according to the method of handling asymmetric membranes such as reverse osmosis membranes,
It is also possible to obtain an asymmetric membrane by stopping the volatilization of the solvent midway and coagulating it in a suitable coagulation medium. Alternatively, the film can also be obtained by hot pressing at a temperature below the decomposition point of the polymer. Furthermore, a dilute solution of these polymers can be used as a composite membrane by forming an ultra-thin membrane on a porous support. It is also possible to directly apply a dilute solution of these polymers onto a porous support and evaporate the solvent to form an ultra-thin film on the porous support, which can be used as a composite membrane. In addition, a solution of these polymers is spread on a suitable solvent that is not compatible with the solvent (for example, water), and the solvent is evaporated.The resulting ultra-thin film is laminated on a porous support to form a composite film. It can also be used as

The thickness of the membrane obtained in this way is 1 mm from 10 people, and as a homogeneous membrane, it is 0.1 μm to 500 μm,
As an asymmetric membrane, a thickness of 0.1 μm to 500 μm can be used, and as an ultra-thin composite membrane, a thickness of 10 μm to 100 μm can be used.

Furthermore, the organic solvent used to obtain the solution of the polymer according to the present invention dissolves these polymers or blends well and evaporates during film formation to form dichloromethane, carbon tetrachloride 1,1,2-trichloro-1 , 2,2 trifluoroethane and other halogenated hydrocarbon solvents are preferably used.

The membrane thus obtained can be incorporated as a flat membrane into a liquid separation membrane device such as a spiral type, plate and frame type, or tubular type. Further, the membrane can also be used in the form of hollow fibers or composite hollow fibers. However, the present invention is not dependent on the shape of these membranes.

The liquid mixture to be separated in the present invention is a mixed liquid of a water-soluble organic substance and water, or a mixed liquid of an organic liquid and an organic liquid. , and ethers such as ethyl ether, tetrahydrofuran, and dioxane; water-soluble ketones such as acetone and methyl ethyl ketone; and water-soluble carboxylic acids such as acetic acid; and mixed liquids of organic liquids include methanol/acetic acid. Filter with methyl, methanol/ethyl acetate, ethanol/ethyl acetate, etc. Among these, it is particularly effective for separating mixed liquids of water-soluble organic substances and water.

[Example] The present invention will be explained in detail below with reference to Examples, in which the separation coefficient α and the permeation flow rate Q can be calculated using the following equations.

α6= (CI /C2>/ (C-1/C-2>C1
: Concentration of component A in the permeate (%) C2: Concentration (%) of component B in the permeate C-1: Concentration of component A in the permeate (%) C-2: Concentration of component A in the permeate (%) a of component B
Degree (%) Q=W/A W: Permeation per hour ff1 (kq/hr) A: Membrane area (Tr12) Reference example 1 1-(tridecafluoro-1,1,2,2,-tetrahydrooctyl ) To 10 ml of a 1M toluene solution of dimethylsilyl-1-propyne were added Q, 2 mm01 of tantalum pentachloride and tetraphenyltin, and the mixture was reacted at 30'C for 24 hours. 1q of the gel-like polymer obtained was dissolved in toluene and reprecipitated with methanol to obtain a polymer.

Example 1 A 3% casting solution was prepared by dissolving 1q of the polymer obtained in Reference Example 1 in 1.1.2-trichloro-1,2,2-trifluoroethane. This solution was cast on a glass plate and the solvent was evaporated to obtain a film with a thickness of 26.9 μm. Using this film, separation was carried out by pervaporation using a 10% aqueous ethanol solution as a feed liquid, a temperature of the feed liquid at 30°C, a pressure on the feed liquid side of 1 atm, and a pressure on the permeate side of 10 mmHg. α''' = 5.35.Q =0.02 (kq/11
2-h) 4-OH.

(Effects of the Invention) Since the present invention has the above configuration, it has the following special effects.

(1) High separation coefficient.

(2) High permeation flow rate.

(3) Good film formability is required.

(4) Easy to cast solvent.

(5) The form of the membrane can be varied. Easy to decompose.

Claims (1)

[Claims] (1) General formula▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) [In the formula, R_1 is a hydrogen atom, a halogen atom, an alkyl group,
It is an alkenyl group or an alkynyl group, R_2,
R_3 and R_4 are aromatic, substituted aromatic, alkyl group, alkenyl group, aromatic substituted alkyl group, or ▲ mathematical formula,
There are chemical formulas, tables, etc.▼ (m and n are integers from 1 to 6), and these R_1 to R
A liquid separation membrane comprising as a main component a polymer containing as a repeating unit, at least one hydrogen atom being replaced with a halogen atom in at least one of _4.