JPH0374337B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is based on the general formula (wherein m is 3 or 4 and n is 0 or an integer from 1 to 10) The present invention relates to a novel electrode membrane comprising a Schiff base type biscrown ether and a thermoplastic resin. Conventionally, organic compounds that selectively coordinate to potassium ions include benzo-15-crown-5, benzo-18-crown-6, dibenzo-18-crown-6, cyclohexyl-18-crown-6, and dibenzo-18-crown-6. Macrocyclic polyethers such as 30-crown-10 and macrocyclic polypeptides such as valinomycin and nonactin are known. Many applications of film-like materials containing these compounds, particularly as potassium electrodes, have been investigated. Potassium electrodes are used to measure potassium ion concentration, particularly to quantify potassium ion concentration in serum quickly and easily. However, most of the potassium electrodes constructed using membrane materials containing macrocyclic polyethers reported so far do not have sufficient selectivity for alkali metal ions other than potassium ions, especially sodium ions. Nakatsuta. It has only been reported that a potassium electrode constructed using a membrane material containing only a few compounds represented by the following general formulas A, B, and C exhibits excellent potassium ion selectivity. (However, n is an integer greater than or equal to 1) (However, n is an integer greater than or equal to 1) (However, n is an integer of 1 or more.) However, the synthesis of any of the above compounds A, B, and C requires multi-step reaction operations, and each reaction requires complicated purification operations. There was a drawback. Furthermore, it has been reported that the synthesis reaction of compound C needs to be carried out under extremely dilute conditions in order to avoid side reactions. In addition, macrocyclic polypeptides such as valinomycin are antibiotics and are extremely expensive, and potassium electrodes constructed using membrane-like materials containing these compounds have the disadvantage of short lifespans. have. The present inventors have made extensive studies to overcome these drawbacks, and have found that a film-like material containing a compound represented by the general formula () selectively interacts with potassium ions, It was discovered that the material can be suitably used as a film-like material constituting an electrode, and the present invention was completed. That is, the present invention provides the following general formula () (However, m is 3 or 4, n is 0 or an integer of 1 to 10) and a thermoplastic resin. This is an electrode film containing 0.1 to 20 parts by weight of crown ether. In the above formula, n is not particularly limited, but in general, n from 0 to 11 is preferably used because of the ease of obtaining the diamine represented by the general formula (), which is a raw material. The Schiff base type biscrown ether represented by the general formula (), which is a component of the film-like material of the present invention, is a new compound, and the identity of the compound can usually be confirmed by the following measurements. (1) Infrared absorption spectrum (1R) Absorption based on cyclic polyether structure is 1270 cm ^-1
It appears strongly near and around 1130cm ^-1 . Further, an absorption peak originating from the aromatic ring appears at 1500 cm ^-1 and an absorption peak originating from the -CH=N- bond appears at around 1620 cm ^-1 to 1640 cm ^-1 . (2) ^1H -Nuclear Magnetic Resonance Spectrum When measured in deuterated chloroform solvent using tetramethylsilane as a standard, the absorption peak derived from H of the -CH=N- group is 7.9 to 8.5 ppm, and is contained in the aromatic ring. The absorption due to H is 6.7 to 7.4 ppm, the absorption due to H of the methylene group contained in the cyclic ether and the peak derived from the H of methylene adjacent to the -CH=N- group is 3.0 to 4.3 ppm, -CH=N (-CH ₂ ) - _o Absorption by H of methylene not adjacent to -CH=N- of N=CH- is 1.2 to 2.2 ppm
The relative intensity ratio of these peaks agrees with the ratio of the number of hydrogens bonded to each group calculated from the above general formula (). (3) Mass spectrometry By using the field desorption method (abbreviated as FD) as a means of mass spectrometry, the molecular ion peak of the compound represented by the general formula () of the present invention can be observed. (4) Elemental analysis This is confirmed by comparing the analysis results of carbon, hydrogen, and nitrogen with the theoretical values calculated from the above general formula (). The properties of the compound represented by the general formula () are:
As is clear from the explanation of the manufacturing method, use, etc., or the results of manufacturing examples, which will be described later, typical properties are as follows. () Schiff base-type biscrown ethers generally cannot be distilled and it is difficult to obtain a clear boiling point. () By normal manufacturing methods, it is obtained as a powdery solid, and is solid at room temperature (25°C). Highly pure substances are white in color, but as their purity decreases, they often turn yellow. () Those in which m in the general formula () is 3 have a unique melting point depending on the number of n,
Generally, temperatures range from 99 to 125°C. However, when n is 0, the temperature is 189 to 191°C. In addition, in the general formula () where m is 4,
Compared to the above m=3, it tends to be more hygroscopic and difficult to measure the melting point, but generally 50 ~
Many have temperatures in the 110℃ range. However, when n is 0, the temperature is 175 to 177°C. () The Schiff base type biscrown ether represented by the general formula () is soluble in various organic solvents. For example, methylene chloride, chloroform,
Benzene, toluene, acetone, tetrahydrofuran, dioxane, dimethylformamide,
It dissolves in methanol etc. at room temperature. In addition, it is dissolved in ethanol, isopropyl alcohol, etc. under heating, and further heated hexane, heptane, etc.
It dissolves in trace amounts in water, etc. Since the above-mentioned properties can be confirmed very easily, it is sufficient to confirm them in advance before use. The method for producing the Schiff base type biscrown ether represented by the general formula () is not particularly limited, and any method may be employed. A specific example of an industrially suitable method is as follows. In other words, the following general formula () (However, m is 3 or 4) and the following general formula () H ₂ N (-CH ₂ )- _o NH ₂ () (However, n is an integer of 0 or 1 or more) A method of obtaining the compound by reacting it with a diamine shown in (a) is preferably used. The raw material compound represented by the general formula () is obtained by reacting 3,4 dihydroxybenzaldehyde with tetraethylene glycol dichloride or pentaethylene glycol dichloride, or by reacting catechol with tetraethylene glycol dichloride or pentaethylene glycol dichloride. A compound represented by the following general formula () (However, m is 3 or 4) It can be obtained by any known method of obtaining the following and then introducing an aldehyde group. The reaction mode for obtaining the compound represented by the general formula () of the present invention from the reaction of the formylbenzo crown ether represented by the general formula () with the diamine represented by the general formula () is not particularly limited, but in general, individual reactions A method in which the aldehyde group and amino group of the raw material are reacted in a solution or suspension state in an inert solvent is preferably employed. Examples of solvents suitably used in the above reaction include aliphatic hydrocarbons such as hexane, heptane, and octane; aromatic hydrocarbons such as benzene, toluene, and xylene; methylene chloride, chloroform,
Aliphatic halogenated hydrocarbons such as trichlorotrifluoroethane; halogenated aromatic hydrocarbons such as chlorobenzene and brombenzene; methanol,
Aliphatic alcohols such as ethanol, isopropanol, butanol, ethylene glycol, diethylene glycol; Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone; Nitriles such as acetonitrile, benzonitrile; Ethers such as diethylene ether, diisopropyl ether, tetrahydrofuran, dioxane, etc. Class;
Examples include esters such as ethyl acetate and methyl acetate; amides such as formamide, dimethylformamide, and dimethylacetamide. The diamine compound represented by the above general formula (), which is a component of the raw material, may be obtained as a salt such as hydrochloride, but in that case, a tertiary amine such as triethylamine or another base is added to the reaction system. By adding , the reaction proceeds smoothly. The reaction temperature for the above general formulas () and () is not particularly limited, but it is generally sufficient to carry out the reaction between 0°C and 150°C. Although the reaction time varies depending on the reaction temperature, reaction solvent, raw material concentration, etc., it is generally within the range of 10 minutes to 50 hours and may be appropriately determined and employed. The compound represented by the general formula () obtained by the above reaction has a high molecular weight and a high boiling point, so it is difficult to distill it. Therefore, it is usually purified by extraction, recrystallization, etc., but depending on the reaction solvent, the desired product can be selectively precipitated as the reaction progresses, and no special post-treatment is required. In some cases, sufficient purity can be obtained by simple filtration. Another component of the film-like material of the present invention is a thermoplastic resin. As the thermoplastic resin used in the present invention, known thermoplastic resins can be used without any restriction.
Since the film-like material of the present invention is usually used in an aqueous solution, the thermoplastic resin is preferably one that does not dissolve in water. Examples of thermoplastic resins suitable for use in the present invention include homopolymers or copolymers of vinyl halides such as vinyl chloride, vinyl bromide, vinylidene chloride, and tetrafluoroethylene; styrene, chlorostyrene; , homopolymers or copolymers of styrene and its substituted products such as bromostyrene; homopolymers or copolymers of acrylic esters or methacrylic esters such as methyl acrylate, ethyl acrylate, ethyl methacrylate, butyl methacrylate, etc. Polymer; homopolymer or copolymer of vinyl ester such as vinyl acetate;
Examples include diene polymers such as butadiene and isoprene, or copolymers of these dienes with styrene, acrylonitrile, etc.; polyurethanes; siloxane polymers or copolymers; cellulose derivatives such as cellulose acetate and cellulose nitrate. The film-like material of the present invention is a film-like material containing a Schiff base type biscrown ether represented by the general formula () and a thermoplastic resin. The compounding ratio of the compound represented by the general formula () is not particularly limited as long as it exhibits the desired properties, but it is generally 0.1 to 20 parts by weight, preferably 1 to 20 parts by weight, based on 100 parts by weight of the thermoplastic resin. It is preferable to use it in a range of 10 parts by weight. When the amount of the compound represented by the above general formula () is less than the above range, the selectivity for potassium ions tends to decrease, and this may be undesirable as a membrane material constituting a potassium electrode. Also,
If the amount exceeds the above range, the compound represented by the general formula () tends to precipitate, and in severe cases, layer separation occurs between the above compound layer and the thermoplastic resin layer, resulting in a non-uniform film-like substance. This is generally not desirable. The thickness of the film-like material of the present invention is not particularly limited, but when used as a film-like material constituting a potassium electrode, it is sufficient to select it within the range of 1 to 1000 μm. In addition, when using the film-like material of the present invention as a film-like material constituting a potassium electrode, it is better to have flexibility, and in general, the tensile modulus of the film-like material (25
℃) is preferably 5000Kg/ ^cm2 or less, especially 10
^{A range of 50 to 2000 Kg/cm 2 is} preferably used. Therefore, when using polyurethanes and polysiloxanes as thermoplastic resins, which generally produce flexible film-like materials, these resins can be used as they are, but thermoplastics, which provide film-like materials that are relatively inflexible, can be used as they are. When using resins such as polyvinyl chloride, polystyrene, etc., it is preferable to use a plasticizer. The plasticizer is not particularly limited and any known plasticizer may be used, but in general the following may be used. For example, phthalic acid esters such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, and dioctyl phthalate; fatty acid esters such as dioctyl adipate and dioctyl sebacate; and orthonitrophenyl alkyl ethers such as orthonitrophenyl octyl ether. The amount of these plasticizers added may be selected appropriately depending on the purpose of use of the film-like material, but in general, 100% of the thermoplastic resin is added.
It is preferable to select the plasticizer in a range of 30 to 300 parts by weight. The method for producing the film-like material of the present invention is not particularly limited. Typical manufacturing methods that are generally suitably employed are as follows. () The compound represented by the general formula () is dissolved in an organic solvent together with a thermoplastic resin or a plasticizer is further added thereto, and the solution is applied or poured onto the top surface of the board, and then the organic solvent is removed. A method of evaporating to form a film. As the organic solvent, any known organic solvent can be used without any restriction as long as it dissolves the thermoplastic resin and the compound represented by the general formula (). Specific examples of generally suitably used organic solvents include tetrahydrofuran, dioxane, chloroform, methylene chloride, dimethylformamide, dimethylacetamide, benzene, and toluene. () There is a method in which a thermoplastic resin and further a plasticizer are added to the compound represented by the general formula (), and the mixture is heated and molded as a raw material to form a film-like material. The heat molding method is not particularly limited, and any known method can be employed. For example, a compound represented by the general formula (), a thermoplastic resin, or a mixture to which a plasticizer is added if necessary is melt-extruded at a temperature equal to or higher than the softening temperature or melting temperature of the thermoplastic resin, and formed into a film-like product. Alternatively, a method may be adopted in which the mixture is formed into a film-like material by hot pressing. The film-like material obtained by the method described above is particularly suitable for use as a film-like material for a potassium electrode.
Any known method can be used without particular limitation as to the manner in which the membrane-like material is formed into a potassium electrode. For example, a solution containing a compound represented by the general formula () shown in () above is poured onto a glass plate, the solvent is removed to form a film-like material, and the film-like material is obtained. A method is to cut out a film-like material to a specified size and attach the film-like material to a membrane holder to make a potassium electrode, or to form a film-like material directly on the surface of a silver wire, platinum wire, etc. and use it as a potassium electrode. Examples include methods. As described above, the membrane material of the present invention has extremely good selectivity to potassium ions, and is ideal as a membrane material constituting a potassium electrode. In addition, the membrane-like material containing the Schiff base-type biscrown ether of the present invention has the ability to selectively transport or selectively absorb potassium salts, and can be applied to the removal and even concentration of potassium salts. It is. Production examples and examples are given below to further specifically explain the present invention, but the present invention is not limited to these production examples and examples. In Examples, the performance of electrodes using the film-like material of the present invention was evaluated using the following apparatus and method. For Examples 1 to 3, the membrane material was attached to the membrane holder shown in FIG. 4, and the electrode performance was evaluated using the apparatus shown in FIG. In Example 4, an electrode having a film-like material formed on the surface of a platinum wire as shown in FIG. 5 was used, and the electrode performance was evaluated by directly attaching it to the electrode part 1 in FIG. 3. The selection ratio of potassium ions to sodium ions can be determined using the "ion selective electrode" (Kyoritsu Shuppan)
(1977) was determined by the mixed solution method described in Chapter 2, Section 3. Specifically, in an aqueous solution containing potassium chloride and sodium chloride, the electromotive force was measured while keeping potassium chloride at a constant concentration (10 ^-4 M) and varying the concentration of sodium chloride. Then, the relationship between electromotive force and sodium chloride concentration was plotted, and the value obtained by dividing the sodium chloride concentration at the inflection point by the potassium chloride concentration was defined as the selection magnification. The higher this value is, the better the potassium electrode is. In addition, we measured the electromotive force of an aqueous solution containing only potassium chloride in a concentration range of 10 ^-1 to ^{10 -5} M, and from the relationship between the electromotive force and the potassium chloride concentration, we calculated the slope as the potassium chloride concentration changes by a factor of 10. The amount of change in electromotive force was determined in units of mV/decade. Moreover, all measurements were performed at 25°C. Production example 1 Add 40 ml of methanol to a 100 ml Erlenmeyer flask containing a magnetic rotor.

2.0 g (6.76 mmol) of the compound represented by the formula (hereinafter simply referred to as 4 ¹ -formylbenzo15 crown 5), 1.02 g (11.4 mmol) of triethylamine, and 0.402 g (3.38 mmol) of diaminomethane hydrochloride. 8 mmol) at 40°C using a water bath with a cooling tube and stirring.
A time reaction was performed. After the reaction, methanol is distilled off,
Add 50ml of chloroform and add water using a separating funnel.
Washed 5 times with 50 ml. After dehydrating the chloroform phase with anhydrous sodium sulfate, chloroform was distilled off. The obtained reaction product was recrystallized from isopropanol to obtain 1.53 g of white crystals. The following analysis was performed on the product obtained with a yield of 75%. (1) Melting point 99-101℃ (2) Infrared absorption spectrum (results are attached as Figure 1) -CH=N- 1640cm ^-1 Aromatic ring 1600cm ^-1 , 1500cm ^-1 Cyclic ether 1270cm ^-1 , 1130cm ^{- 1} (3) ¹ H-nuclear magnetic resonance spectrum (results are attached as Figure 2) Measurement solvent: Deuterated chloroform Standard: Tetramethylsilane (a) 8.0 δ(ppm) (b) 6.7~7.4 δ(ppm) (c)+(d) 3.5~4.3 δ(ppm) (4) Mass spectrometry spectrum FD method m/e=602 (M ⁺ ) ( 5) Elemental analysis

[Table] From the above measurement results, it was confirmed that the product was the desired product. Production example 2 Add 0.203 g of ethylenediamine (3.28
mmol) 4'-formylbenzo 15 crown 5
Prepare 2.0g (6.78 mmol) and 50ml of benzene,
While stirring with a magnetic rotor and heating with an oil bath, azeotropic dehydration was performed for 4 hours. During this time, 0.12 ml of water was azeotropically dehydrated. After the reaction, benzene was distilled off and the product was recrystallized from isopropanol to give white crystals (melting point
1.71 g (104-105°C) was obtained. Yield 82%. Manufacturing example 1
The product was confirmed to be the desired product using the same analytical method as described above. Production example 3-13 5.0 g (16.9 mmol) of 4 ¹ -formylbenzo 15 crown 5 in an Erlenmeyer flask with an internal volume of 200 ml, general formula
8.45 mmol of diamine represented by H ₂ N(-CH ₂ ) _-o NH ₂ and 100 ml of ethanol were added, and the mixture was reacted at 30° C. with stirring using a magnetic rotor. A white precipitate began to precipitate about 1 hour after the start of the reaction. After reacting for 8 hours, the white precipitate was filtered off and dried under reduced pressure. The yields and melting points of the reactants are summarized in Table 1.

[Table] Note that n shown in Table 1 corresponds to n in the structural formula shown in general formula (). The products obtained in Production Examples 3 to 13 were confirmed to be the desired products by the analytical method described in Production Example 1. In addition, in addition to the absorption of the products obtained in Production Examples 1 and 2, the nuclear magnetic resonance spectra of the target products obtained in Production Examples 4 to 13 include -CH=N- CH ₂ (-CH ₂ )- _{o -2} CH _2- N=CH
- Absorption due to (-CH ₂ )-o _-2 in the structure is 1.4 to 2.2 ppm
was seen in Production example 14 50 ml of methanol in an Erlenmeyer flask with an internal volume of 100 ml and a stopper containing a magnetic rotor, general formula

2.0g of [Formula] (hereinafter simply abbreviated as 4 ¹ formylbenzo 18 crown 6)
(5.88 mmol), triethylamine 1.0 g (9.9 mmol), diaminomethane hydrochloride 0.345 g (2.9
mmol) and reacted at 50° C. for 8 hours with a cooling tube attached and stirring. After the reaction, ethanol was distilled off, and 1.2 g of white crystals were obtained in the same manner as described in Production Example 1. The obtained product was analyzed in the same manner as in Production Example 1, and it was confirmed that the product was the desired product. Production example 15-23 General formula: 3.0 g (8.82 mmol) of 4 ¹ formylbenzo 18 crown 6 in an Erlenmeyer flask with an internal volume of 200 ml.
4.4 mmol of an alkyldiamine represented by H ₂ N(-CH ₂ ) _-o NH ₂ and 100 ml of ethanol were added, and the mixture was reacted at 30° C. for 8 hours while stirring with a magnetic rotor.
After the reaction, ethanol was distilled off, and the product was recrystallized from isopropanol, filtered, and dried under reduced pressure.
The reaction product was analyzed by the same method as described in Production Example 1, and it was confirmed that the product was the desired product. The results are shown in Table 2. Note that n in Table 2 corresponds to n of the compound represented by the general formula ().

[Table] Example 1 10 mg of the compound represented by the general formula (), a thermoplastic resin, and a plasticizer having the composition shown in Table 3 were dissolved in 10 ml of tetrahydrofuran. After this solution was cast on a smooth glass plate, the tetrahydrofuran was evaporated to obtain a film about 100 microns thick.
The performance of electrodes constructed using these membrane materials was evaluated in the third
The electrode performance is shown in the table.

【table】

[Table] Example 2 20 mg of the compound represented by the general formula () and 600 mg of poly(bisphenol A carbonate)-poly(dimethylsiloxane) block copolymer (composition 49:51 weight ratio) were mixed with 20 c.c. of methylene chloride. dissolved in. After this solution was cast on a smooth glass plate, the methylene chloride was evaporated to obtain a film about 100 microns thick. Table 4 shows the performance of electrodes constructed using these membrane materials.

【table】

[Table] Corresponds.
Example 3 20 mg of the compound represented by the general formula (), a thermoplastic resin, and a plasticizer having the composition shown in Table 5 were dissolved in 3 ml of tetrahydrofuran. This solution has an outer diameter of 0.5
After immersing a mm platinum wire for 10 seconds, it was taken out of the solution and left to stand for 10 minutes to evaporate the solvent, tetrahydrofuran. This operation was repeated 10 times to form a film on the surface of the platinum wire. In order to avoid contact between the measurement solution and the platinum wire, the exposed platinum part was covered with a tape made of tetrafluoroethylene. FIG. 5 shows an outline of this platinum wire coated with a film-like substance. The electrode performance of these film-covered platinum wires was evaluated. The results are shown in Table 5 as electrode performance.

【table】 [Brief explanation of drawings]

FIG. 1 and FIG. 2 are an infrared absorption spectrum and a ¹ H-nuclear magnetic resonance spectrum of the compound obtained in Example 1, respectively. FIG. 3 is an explanatory diagram of an apparatus for measuring electromotive force, and FIG. 4 is an explanatory diagram showing various constituent elements built into the electrode 1 of FIG. 3. FIG. 5 is a schematic diagram of a platinum wire coated with the film-like material of the present invention. In FIG. 3, FIG. 4, and FIG. 5, each number indicates the following content. DESCRIPTION OF SYMBOLS 1... Electrode, 2... Measurement solution, 3... Magnetic rotor, 4... Magnetic stirrer, 5... IM lithium acetate salt bridge, 6... Potassium chloride saturated aqueous solution, 7... Saturated electrode, 8... ... Electrometer (Hokuto HE-103 type), 11 ... Acrylic membrane holder, 12 ... Silver wire, 13 ... Covered glass tube, 14
...Silver-silver chloride circle standard electrode, 15...10 ^-3 M potassium chloride internal standard solution, 16... Membrane, 17...
...O-ring, 21...Platinum wire, 22...Membrane-like material, 23...Teflon tape.

Claims (1)

[Claims] 1. General formula {where m is 3 or 4 and n is 0 or an integer of 1 to 10} It is composed of a Schiff base type biscrown ether and a thermoplastic resin, and the Schiff base type biscrown ether is added to 100 parts by weight of the thermoplastic resin. An electrode membrane containing 0.1 to 20 parts by weight of ether.