JPH041239A - Production of ion-sensitive film - Google Patents

Abstract

PURPOSE:To improve the sensitivity to Cl ion and resistance to org. staining by forming a specific linear polymer into a film and crosslinking the film. CONSTITUTION:A compsn. obtd. by compounding a linear polymer comprising 10-90mol% units of formula I and 90-10mol% units of formula VI (wherein R<4> is H or 5C or lower alkyl) with 10-200wt.% 10C or higher liner alcohol is formed into a 0.1mum to 5mm thick film, which is thermally crosslinked at 30 deg.C or higher. In formula I, Y is H, alkyl, or cyano; X<-> is a halogen ion or a group of atom forming an anion; Z is a group of formula II to V; n is 1-10; R<1> and R<2> are each 5C or lower alkyl, halogenated alkyl, hydroxyakyl, or benzyl; A is a monovalent nonionic group having two or three long-chain hydrophobic groups or one long-chain hydrophobic group contg. a rigid segment in the chain; B<1> and B<2> are each a monovalent nonionic long-chain hydrophobic group; R<3> is -(CH2)m-, -CH2(CH2OCH2)mCH2-, etc.; and m is n.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing a novel ion-sensitive membrane for use in an ion-selective electrode for measuring the activity of ions in a solution. Specifically, it is a method for producing an ion-sensitive membrane that has excellent sensitivity to chloride ions when used as a boundary membrane of an ion-selective electrode.

[Problems to be solved by conventional techniques and inventions] In recent years,
Ion-selective electrodes are applied for medical purposes to detect ions dissolved in biological fluids such as blood and urine, such as sodium ions,
Many attempts are being made to quantify potassium ions, chloride ions, etc.

This is based on the fact that the concentration of specific ions in biological fluids is closely related to the metabolic reactions of the body, and by measuring the concentration of these ions, various symptoms such as hypertension, heart disease, kidney disease, neurological disorders, etc. can be detected. It is used for diagnosis.

Generally, an ion-selective electrode is placed in a cylindrical container 11, which has an ion-sensitive membrane 1112 as a boundary membrane in the part (generally the bottom) that is immersed in the sample liquid, as shown in FIG.
It is basically configured by providing an internal electrolyte 13 and an internal reference electrode 14.

FIG. 2 shows a typical structure of an ion measuring device for measuring the activity of ions in a solution using such an ion-selective electrode. That is, the ion-selective electrode 21 and the salt bridge 22 are immersed in the sample solution 23, and the other end of the salt bridge is immersed together with the reference electrode 24 in the saturated potassium chloride solution 26. The potential difference between both electrodes is read by an electrometer 25,
The ionic activity of a specific ion species in the sample solution can be determined from the potential difference. The performance of the ion-selective electrode used in such an ion measuring device is determined by the performance of the ion-sensitive membrane used therein.

Conventionally, various membranes have been proposed as ion-sensitive membranes for selectively detecting anions, particularly chloride ions. For example, a) a solid formed film mainly composed of silver chloride b) a film formed by mixing a polymer such as polyvinyl chloride, an ion-sensitive substance such as a quaternary ammonium salt, and a plasticizer c) a film formed by mixing a plasticizer with a trimethylammonium group, pyridinium Membranes such as anion exchange membranes made of polymers having ion exchange groups such as groups are known. However, in an ion-selective electrode using the ion-sensitive membrane of type (a), if bromide ions, cyanide ions, thiocyanate ions, etc. are present in the solution, the membrane surface will undergo chemical changes due to the influence of these ions. Therefore, it is difficult to stabilize the potential, and in extreme cases, potential measurement may become impossible. In addition, when measuring various biological fluids, etc., they are easily affected by proteins, etc.
The drawback is that the potential is not stable. An ion-selective electrode using an ion-sensitive membrane of the type (b) has the drawback of slow response and short electrode life because the ion-sensitive substance in the membrane gradually dissolves into the solution. (C
) type of ion-selective electrode using an ion-sensitive membrane has the advantage of a long life because the ionic group is covalently introduced into the polymer constituting the membrane. Anion exchange membranes having groups are generally ion exchange layers used for electrolysis, and when used as ion-sensitive membranes, they are greatly affected by interfering ions other than chlorine ions, such as phosphate ions and hydrogen carbonate ions. It also has the disadvantage that the potential obtained is unstable. The present inventor proposed an ion-sensitive membrane made of a linear polymer into which a specific hydrophobic group such as a long-chain alkyl group is introduced in order to improve the selectivity of the ion-sensitive membrane to chloride ions.

(Unexamined Japanese Patent Publication No. 01-232250). However, although the above-mentioned ion-sensitive membrane shows good ion selectivity,
This method has the problem of being easily contaminated by organic matter in the sample solution. Therefore, it has been desired to develop an ion-sensitive membrane that can measure chloride ions in biological fluids with high sensitivity and provides an ion-selective electrode with excellent resistance to organic contamination.

[Means for Solving the Problems] The present inventors have conducted extensive research in order to develop an ion-sensitive membrane that can solve these problems. As a result, by combining and crosslinking specific units with the units that make up the linear polymer into which specific hydrophobic groups are introduced, which makes up the ion-sensitive membrane, it has excellent ion sensitivity to chloride ions. The present inventors have now completed the present invention by discovering that an ion-sensitive membrane can be obtained which also has good resistance to organic contamination.

That is, the present invention relates to the following general formula [I] or [II] [I]
[II] (However, Y is a group selected from hydrogen, an alkyl group, and a cyano group, X- is a halogen ion or an atomic group forming an anion, Z is -〇COR'--CONHR'-1 and - NHCOR'
-(However, R' is +CH2+-1-CHx+CH20C
H2+-CH2-1 or -CHz+CH (OIs) 0
CH2+CH(Cats) -1 (however, m is 1 to 10
), n is an integer of 1 to 10), Rl and R2 are the same group selected from alkyl groups having 5 or less carbon atoms, halogenated alkyl groups, hydroxyalkyl groups, and benzyl groups; The heterogeneous group A is a nonionic monovalent group having either two or three long-chain hydrophobic groups or one straight-chain hydrophobic group containing a rigid part in the chain, and B1 ．． B2 represents the same or different nonionic monovalent long chain hydrophobic group. ) contains 10-01% or more of units represented by the following general formula [111] % formula % [111] (However, Y is a group selected from hydrogen, an alkyl group, and a cyano group, and R4 is hydrogen or Indicates a group selected from alkyl groups having 5 or less carbon atoms.) 10% 01%
This is a method for producing an ion-sensitive membrane, which comprises forming a linear polymer containing the above into a membrane shape, and then crosslinking the linear polymer.

The linear polymer used in the method of the present invention contains a unit having a specific quaternary ammonium group shown in the above-mentioned [I] and [I[] in its molecule and is ion-sensitive. This is necessary to dramatically improve the selectivity of the membrane for chloride ions.

In the present invention, in the above-shipped warehouse [I] and [I[], Y
The alkyl group represented by is not limited in terms of the number of carbon atoms, but those having 1 to 4 carbon atoms are preferably used because of their easy availability. The halogen ions represented by
The atomic groups that form the stable anion shown are:
Known atomic groups may be used without particular limitation, but generally NO
3-.

ClO4-, OH-, 5CN-, CH, COO-, etc. are preferably used. Furthermore, as the alkyl group having 5 or less carbon atoms, or its halogen-substituted product, or hydroxyl-substituted product represented by Rl and R2 in the above-mentioned -Senzo [I] and [nl, generally known ones can be used without particular restriction. However,
Examples of those preferably used include methyl group, ethyl group, propyl group, butyl group, pentyl group, chloromethyl group, 2,2-dichloroethyl group, 2-chloroethyl group,
These include 3-chloropropyl group, 2-bromoethyl group, hydroxymethyl group, 2-hydroxyethyl group, 3-hydroxypropyl group, and the like. When the number of carbon atoms in the alkyl group is 6 or more, the selectivity of the resulting ion-sensitive membrane may decrease. In the above-shipped [I] and [nl, Z is -0COR'--CONHR'-1 and -NHCOR'
- (However, R' is +CHZ) -1-CH2+CH20C
Hz+-CH2-1 or bar CH2+CH([)1ri0C
H2+CH(OI,)-2 (where m is an integer of 1 to 10, preferably 1 to 4), n is 1 to 10, preferably 1
-4 integers). By using these groups, raw materials can be easily obtained and polymers can be manufactured easily.

In the present invention, in the above-mentioned - Shipura [I], A is a nonionic having either two or three long-chain hydrophobic groups, or one straight-chain hydrophobic group containing a rigid part in the chain. It is a monovalent group (hereinafter abbreviated as a hydrophobic group). The presence of the hydrophobic group in the polymer constituting the ion-sensitive membrane of the present invention improves the selective sensitivity of the resulting ion-sensitive membrane and increases its stability when used in water. I can do it.

In the present invention, the long-chain hydrophobic group among the hydrophobic groups is a straight-chain alkyl group having 10 to 30 carbon atoms or a halogen-substituted product thereof, in view of the ion selectivity of the resulting ion-sensitive membrane and the ease of obtaining raw materials. It is preferable. In addition, the long-chain hydrophobic group referred to in the present invention refers to a completely linear hydrophobic group, as well as a group with a carbon number of 2.
It also includes branch schools with up to 1 branch schools.

One embodiment of the hydrophobic group of the present invention has two or three long-chain hydrophobic groups. If there is only one long-chain hydrophobic group, the resulting ion-sensitive membrane will not have sufficient water resistance, and if there are four or more long-chain hydrophobic groups, it will be difficult to obtain raw materials for polymer production.

In addition, in a nonionic monovalent group having one straight-chain hydrophobic group containing a rigid part in the chain, the rigid part is one of the following and the groups shown in (1).

■ A divalent group consisting of at least two aromatic rings connected directly or via a carbon-carbon multiple bond, a carbon-nitrogen multiple bond, an ester bond, an amide bond, etc. For example, CH3 CH.

Examples include divalent groups such as.

■ A divalent group in which the bonds between the aromatic rings are multiple or a single bond with or without an atomic group, and the rotation of which is energetically constrained. To give an example, ① Aromatic rings form a condensation, and when this condensed ring is stacked between multiple molecules, the rotation of the condensed rings is sterically constrained to each other. Specific examples of the group include divalent groups such as the following.

The number of carbon atoms in the linear hydrophobic group of the hydrophobic group having one linear hydrophobic group containing a rigid part in the chain is 4 to 30 in view of the water resistance of the resulting ion-sensitive layer and the ease of obtaining raw materials. It is preferable. The number of carbon atoms referred to herein means the number of carbon atoms in the portion excluding the rigid portion and the bonding portion between the rigid portion and the linear hydrophobic group. The bond between the rigid portion and the linear hydrophobic group is generally preferably a carbon-carbon bond, an ester bond, or an ether bond. It is necessary that the number of straight hydrophobic groups containing a rigid portion in the chain is one. That is, if the number of Il[Ia hydrophobic groups is two or more, it will be extremely difficult to mix with the polymer and to form the grooves, and the stability of the ion-sensitive layer will often be affected, which is undesirable.

In the present invention, the hydrophobic group is not particularly limited as long as it satisfies the above conditions, and known hydrophobic groups can be used. Representative ones that are generally suitably used are specifically shown below.

■ R'-C-0+CH22 However, R5 and R6 are the same or different straight-chain alkyl groups having 12 to 30 carbon atoms or their halogen-substituted products, and D is + E + J + CH2+ k (however, E is k
is a positive integer.

and h.

j is a positive integer It is a number.

■ O layer R5-OC-CH+N HCOD +r[B] R'-OC+ CH2) however, R', R', D.

and j are the same as above. ri is 1 or 2.

■ R'-0CR.

HCO+CHe- to R'-0CH2 [C] is an alkyloxy group, an alkyloxycarbonyl group, or a halogen-substituted product thereof, (wherein, W is -N=CH-, -N=N-, -C,H=CH-,-
NO=N-.

However, R5 and R6 are the same as above and are integers.

■ R'-V-G- [D] k is positive. )G is +CH2+ or -O+ CH2
+, is. (However, p is a positive integer, and is an alkyl group having 4 to 22 carbon atoms.) Above - Shipping [A, [B], [C], [D
], k and p may be positive integers, but are generally preferably 1 to 16 from the viewpoint of easy availability of raw materials. Further, in the above-mentioned - Shipping [A], h and j may take any positive integer without any restriction, but it is generally preferable that they be from 1 to 4 from the viewpoint of easy availability of raw materials. Furthermore, the above-shipped [
A], [B, [C] and [D], R5 and R
Examples of the halogen atom in the halogen-substituted alkyl group represented by 6 include fluorine, chlorine, bromine, and iodine atoms.

B1 and B2 in [n] are the same or different nonionic monovalent long-chain hydrophobic groups. The presence of the long-chain hydrophobic group in the polymer used in the present invention improves the selectivity of the resulting ion-sensitive membrane and increases its stability when used in water.

The above-mentioned long-chain hydrophobic group has a carbon number of 1 due to the ease of obtaining raw materials.
2 to 30 straight chain alkyl groups or halogen substituted products thereof,
It is preferably a group selected from a straight-chain alkylcarboxyalkyl group or a straight-chain alkyloxycarbonylalkyl group. Further, specific examples of more suitable groups are as follows.

R'+T-U+J [E] (However, R8
is a straight-chain alkyl group having 12 to 30 carbon atoms or a halogen-substituted product thereof, T is -COO- or -0CO-, and U is +CH2-)-.

And 1. j is the same as above. ) In the above - Shipping [E], q can be used without any restriction as long as it is a positive integer, but it is preferably from 1 to 5 from the viewpoint of easy availability of raw materials. Further, the halogen atom of the halogen-substituted alkyl group represented by R8 includes fluorine, chlorine, bromine, and iodine atoms.

The linear polymer used in the method of the present invention contains a unit having a specific methylol group in its molecule as shown in [■] above, which dramatically improves the organic contamination resistance of the ion-sensitive membrane. It is necessary to improve.

In the polymer constituting the ion-sensitive membrane of the present invention, the above-
Although the number of carbon atoms of the alkyl group represented by Y in [II] is not limited, those having 1 to 4 carbon atoms are preferably used because of easy availability of raw materials. The group represented by R4 is not particularly limited as long as it is hydrogen or an alkyl group having 5 or less carbon atoms, but hydrogen is particularly preferably used because it facilitates the crosslinking reaction described below.

In the present invention, general formula [I] constituting the linear polymer
Or the molar fraction of the unit represented by [II] based on the total polymer is 10so1% or more, preferably 30so1%
It is preferable that it is above. The fraction of the above unit is 10
If the mo amount is less than 1%, the chloride ion selectivity of the resulting ion-sensitive membrane may be insufficient, and the stability when used in water may deteriorate. Furthermore, in the polymer constituting the ion-sensitive membrane of the present invention, - marine [1
The molar fraction of the unit represented by [ ] with respect to the total polymer is preferably 10mol% or more, preferably 30mol% or more. The proportion of the above units is 10 schools o1%
If it is less than that, the crosslinking of the resulting ion-sensitive membrane may be insufficient and the organic contamination resistance may not be improved.

The linear polymer used in the present invention has the general formula [I
] or [] I] and at least one unit shown as [I[[], but other units forming a linear polymer may be It may contain units. As such a unit, a unit represented by the following formula [■] is preferably used.

CH2C[[V] (However, P is hydrogen, a halogen atom, a cyano group, an alkyl group, or a carboxyl group, and Q is an alkyl group, a carboxyl group, a phenyl group, a naphthyl group, an alkylcarboxyl group, an alkyloxycarbonyl group, (Aminocarbonyl group, alkyloxy group, amino group, alkylamino group, trimethylammonioalkyl group, and their halogen-substituted or hydroxyl-substituted products.) The number of carbon atoms in the unit shown in [IV] above is based on the raw material. It is preferable that the number is 10 or less, taking into consideration the ease of obtaining the polymer and the film-forming property of the resulting polymer. Further, the molar fraction relative to the polymer is preferably 40.01% or less.

The molecular weight of the linear polymer used in the present invention is not particularly limited, but preferably has a number average molecular weight of 5,000 or more, more preferably 10,000 or more. When the number average molecular weight is 5000 or less, the resulting ion-sensitive membrane becomes fragile. Moreover, when the number average molecular weight is 10,000 or less, the resulting ion-sensitive membrane may have insufficient stability in water.

As explained above, the linear polymer used in the present invention is a polymer having a specific amount or more of units represented by the general formula [1 or [IN and I] (hereinafter abbreviated as an ion-exchangeable polymer). ) is the constituent component. The method for producing the ion-exchangeable polymer is not particularly limited and any known method may be employed, but generally preferred methods include the following methods.

■ A method of copolymerizing a monomer having the structure shown by [V] or [VI] below with a monomer having the structure shown by [■] below.

C: CH2 C=O N-R' H20H [■] (However, y, z, x-1R1, R2, R4,
The definitions and preferred examples of A, B', and B2 are as described above. ) An ion-exchangeable polymer containing a third component can also be obtained by adding a monomer copolymerizable with these monomers during the above polymerization. - As the monomer copolymerizable with the monomer represented by [V] or [VI] and [■], known monomers can be used without particular limitation. Typical examples that are generally suitably used include, for example, solenoid compounds such as ethylene, propylene, and butene; halogen derivatives of solenoid compounds such as vinyl chloride and hexafluoropropylene; styrene, vinylnaphthalene, etc. Aromatic vinyl compounds; vinyl ester compounds such as vinyl acetate; acrylic acid derivatives and methacrylic acid derivatives without methylol groups such as methyl acrylate, methyl methacrylate, 2-hydroxyethyl methacrylate, acrylamide, methacrylamide; acrylonitrile, etc. unsaturated nitrile compounds; vinyl ether compounds such as methyl vinyl ether; and quaternary ammonium compounds such as methyl vinyl pyridinium iodide and trimethylammonioethyl chloride methacrylate. In addition to the above, vinyl carboxylic acid compounds such as acrylic acid and methacrylic acid; sulfonic acid compounds such as styrene sulfonic acid and vinyl sulfonic acid may also be suitably used;
If such anionic monomers are used, an ion-sensitive membrane that does not respond to anions may result, so the anionic groups/l! ! Ratio of ionic groups (equivalence ratio)
must be less than 1.

The polymerization method used to produce the ion-exchangeable polymer is not limited to ionic polymerization, radical polymerization, etc., but it is preferable to carry out the polymerization in the presence of a radical initiator. As for the polymerization operation, generally known operations can be used without particular restriction, but solution polymerization is preferably used from the viewpoint of the homogeneity of the obtained polymer and the ease of controlling the composition ratio of the copolymer. The solvent for solution polymerization is not particularly limited as long as it dissolves the monomers used. Generally preferred ones include water, methanol, ethane, acetone, benzene, dimethylformamide, dichloromethane,
Examples include tetrachloromethane, chloroform, tetrahydrofuran, dichloroethane, and chlorobenzene.

Two or more of the above solvents may be used in combination. The polymerization temperature is preferably 0°C to 150°C, and 40°C to 1
00°C is more preferred. In addition, various methods known in the art can be used to isolate the ion exchange polymer, but in the case of solution polymerization, the reaction mixture is poured into a solvent that does not dissolve the produced polymer. A reprecipitation method is preferred.

(2) A method of copolymerizing a monomer with a structure represented by [V] or [V] below with a monomer having a structure represented by [■] below, and then converting the polymer into methylol.

C=CH2 C=O N-R' [■] (However, y, z, x-1R1, R2, R4,
Regarding the definitions and preferred examples of A, Bl, and B2,
As mentioned above. ) By adding a vinyl monomer copolymerizable with these monomers during the above polymerization,
It is also possible to obtain an ion exchange polymer containing a third component. As the vinyl monomer that can be copolymerized with the vinyl monomer represented by [V] or [VI] and [■], known monomers can be used without particular limitation. Typical examples that are generally suitable for use include, for example:
Olefin compounds such as ethylene, propylene, butene;
Halogen derivatives of olefin compounds such as vinyl chloride and hexafluoropropylene; Aromatic vinyl compounds such as styrene and vinylnaphthalene; Vinyl ester compounds such as vinyl acetate; Methyl acrylate, methyl methacrylate, 2
-Hydroxyethyl methacrylate, acrylic ester derivatives and methacrylic acid ester derivatives; unsaturated nitrile compounds such as acrylonitrile; vinyl ether compounds such as methyl vinyl ether; quaternary ammonium compounds such as methylvinylpyridinium iodide and trimethylammonioethyl methacrylate chloride etc. In addition to the above, vinyl carboxylic acid compounds such as acrylic acid and methacrylic acid; sulfonic acid compounds such as styrene sulfonic acid and vinyl sulfonic acid can also be suitably used; however, when using the anionic monomer, This may result in an ion-sensitive layer that does not respond to anions.
Ratio of anionic groups/cationic groups in the polymer (equivalence ratio)
must be less than 1.

The polymerization method for producing the above polymer is not particularly limited, such as ionic polymerization or radical polymerization, but it is desirable to carry out the polymerization in the presence of a radical initiator.

Regarding the polymerization operation, any known operation in -a can be used without particular limitation, but solution polymerization is preferably used in terms of the homogeneity of the obtained polymer and the ease of adjusting the composition ratio of the copolymer. . The solvent for solution polymerization is not particularly limited as long as it dissolves the monomers used. Those generally preferably used include water, methanol, ethanol, acetone, benzene, dimethylformamide, dichloromethane, tetrachloromethane, chloroform, tetrahydrofuran, dichloroethane, and chlorobenzene. Two or more of the above solvents may be used in combination. The polymerization temperature is preferably 0°C to 150°C, more preferably 40°C to 100°C. In addition, various methods known in the art can be used to isolate the ion exchange polymer, but in the case of solution polymerization, the reaction mixture is poured into a solvent that does not dissolve the produced polymer. A reprecipitation method is preferred.

As a method for methylolizing the above-mentioned polymer, generally known methods can be used without particular restriction. Examples of generally preferred methods are as follows. That is, a method in which a polymer is placed in an aqueous formaldehyde solution and reacted at a temperature of 5°C or more for 30 minutes or more. At this time, a water-miscible solvent may be present in the formaldehyde aqueous solution. reaction temperature is 0°
If the reaction time is less than C or the reaction time is less than 30 minutes, the methylolization of the resulting ion-exchangeable polymer may be insufficient and the organic contamination resistance of the ion-sensitive membrane may be poor.

The ion exchange polymer produced as described above is -
It is a colorless, white or pale yellow solid. Although it is sparingly soluble in water, it dissolves in organic solvents such as dimethylformamide, chloroform, tetrachloromethane, dichloromethane, tetrachloroethane, and tetrahydrofuran at room temperature to 100°C. Generally, the general formulas [I] or [n] and [I[
The content of the unit represented by I] is determined by elemental analysis.

In the present invention, the ion-sensitive membrane is obtained by forming an ion-exchangeable polymer into a membrane shape and then subjecting it to a crosslinking reaction.

The method for forming the ion-exchangeable polymer obtained by the above production method into a film-like material is not particularly limited, and any method may be used. Examples of generally preferred methods are as follows.

(2) A method of obtaining a film-like material by dissolving an ion-exchangeable polymer in a soluble solvent, casting the solution onto a suitable substrate, and then removing the solvent. The solvent used here is not particularly limited as long as it dissolves the ion exchange polymer, but
The soluble solvents described in the above-mentioned method for producing an ion-exchangeable polymer are preferably used. To remove the above-mentioned solvent, air drying, vacuum drying, etc. are generally used without particular limitation.

■ A method of forming a film-like material by thermoforming and stretching an ion-exchangeable polymer. The temperature during heat molding is around the softening point of the ion exchange polymer, and varies depending on the type of ion exchange polymer, but is generally between 50 and 200℃.
Selected in the range of °C.

The thickness of the film-like material obtained by the above molding is not particularly limited, but is generally 0.1 μm to 5 mm, preferably 5 to 10 μm.
A range of 0 μm is preferable because it can provide the obtained ion-sensitive membrane with a film strength sufficient for practical use.

In the present invention, the ion-sensitive membrane is obtained by subjecting the above-mentioned ion-exchangeable polymer to a crosslinking reaction.

As the crosslinking method, a generally known crosslinking method for N-methylol groups can be used as is. Examples of generally preferred methods are as follows.

■ A method of crosslinking by heating an ion exchange polymer. Heating is preferably carried out in water for ease of temperature control. At this time, it is effective to carry out the reaction at a temperature of 30°C or higher, more preferably 40°C or higher, in order to cause a sufficient crosslinking reaction.

■ A method of immersing an ion exchange polymer in an acid aqueous solution and crosslinking it. As the acid aqueous solution to be used, known acid aqueous solutions can be used for -a, but examples of acid solutions that are preferably used include hydrochloric acid, hydrobromic acid, sulfuric acid, perchloric acid, para-toluenesulfonic acid, and nitric acid. , acetic acid, phosphoric acid, etc. An organic solvent miscible with water may be present in the acid aqueous solution used. Soaking is generally carried out at temperatures above 5° C. for 5 minutes or more, which is necessary to improve the organic contamination resistance of the resulting ion-sensitive membrane. More preferably, immersion in an acid aqueous solution at 50'C or higher for 10 minutes or more is effective for significantly improving the organic contamination resistance of the resulting ion-sensitive membrane.

Generally, the formation of the above-mentioned crosslinking reaction occurs because the obtained ion-sensitive membrane becomes insoluble in the solvent that dissolves the above-mentioned ion-exchangeable polymer. I can recognize it.

The ion-sensitive membrane obtained as described above generally often exhibits liquid crystallinity as its basic property. The temperature range that exhibits liquid crystallinity is in the range of 0 to 200"C. Liquid crystallinity is generally confirmed by measurement using a differential scanning calorimeter. If it is a liquid crystal, it undergoes a transition from solid to liquid crystal at a certain temperature. The amount of heat associated with this is observed, and that temperature is called the solid-liquid crystal transition temperature.Therefore, the ion-sensitive film obtained by the method of the present invention has a temperature below the solid-liquid crystal transition temperature, more preferably below the solid-liquid crystal transition temperature. It is desirable to use it at a temperature lower than 10° C. If it is used at a temperature higher than the solid-liquid crystal transition temperature, the selectivity for various anions, especially divalent anions, may decrease.

In order to improve the selectivity of the ion-sensitive membrane of the present invention to chloride ions, it is preferable to immerse the ion-exchangeable polymer used in water at a temperature equal to or higher than its solid-liquid crystal transition temperature for 1 minute or more before crosslinking. This operation improves the selectivity and sensitivity of the resulting ion-sensitive membrane to chlorine ions, and by using this as a sensitive membrane of an ion-selective electrode, chloride ions can be measured with high sensitivity.
Furthermore, the potential to be measured is often stable.

In the method of the present invention, by allowing a linear alcohol having 10 or more carbon atoms to exist in the ion exchange polymer,
The selective sensitivity of the resulting ion-sensitive membrane to chlorine ions can be further improved.

That is, the ion-sensitive membrane of the present invention has good selective sensitivity of chloride ions to divalent anions and is suitable for measuring chloride ions in biological fluids. The presence of a linear alcohol with a carbon number of 10 or more in the molecule allows fat-soluble monovalent anions such as thiocyanate ion, perchlorate ion, and nitrate ion to be used without reducing the selective sensitivity to divalent anions. We have found that the selective sensitivity to ions can be further improved.

If the number of carbon atoms in the linear alcohol is less than 10, the resulting ion-sensitive membrane will have insufficient water resistance. Further, the need for the alcohol to be linear is to improve compatibility with other constituent components.

The linear alcohol used in the present invention is not particularly limited as long as it satisfies the above conditions, and any known one can be used. Generally, in consideration of the water resistance of the resulting ion-sensitive membrane and the ease of obtaining raw materials, linear alcohols having 16 to 18 carbon atoms are preferably employed.

In the present invention, the linear alcohol is contained in an amount of 10 to 15% ON based on the amount of the ion-exchangeable polymer. If the linear alcohol content is 10% by weight or less, the ion selectivity of the resulting ion-sensitive membrane may not be sufficiently improved.

Furthermore, if the content is 150% by weight or more, the resulting ion-sensitive membrane may have insufficient water resistance and strength.

The method of adding and mixing linear alcohol to the ion-exchangeable polymer and forming it into a film-like material is not particularly limited, and any method may be used. Examples of generally preferred methods are as follows.

(2) A method of obtaining a film-like material by dissolving an ion exchange polymer and a linear alcohol in a soluble solvent, casting the solution on a suitable substrate, and then removing the solvent.

The solvent used here is not particularly limited as long as it dissolves the ion exchange polymer and the linear alcohol, but the soluble solvents described in the above-mentioned method for producing an ion exchange polymer are preferably used. To remove the above-mentioned solvent, air drying, heat drying, reduced pressure drying, etc. are generally used without particular limitation.

(2) A method in which an ion-exchange polymer and a linear alcohol are dissolved in a soluble solvent, the solvent is removed, and the resulting film is formed by heating and stretching.

The soluble solvent used here varies depending on the solubility of each component, but generally dimethylformamide, dichloromethane, chloroform, tetrahydrofuran, dichloroethane, chlorobenzene, 1. 1. 2
．． Preferably, 2-tetrachloroethane is used.

To remove the above-mentioned solvent, air drying, heat drying, reduced pressure drying, etc. are generally used without particular limitation. The temperature during the above-mentioned thermoforming is around the softening point of the ion exchange polymer, and varies depending on the type of ion exchange polymer, but is generally 50°C.
~200'C.

[Effects] The ion-sensitive membrane obtained by the present invention has a quaternary ammonium group having a specific structure, which is an ion-sensitive moiety, fixed in a polymer by covalent bonds. Therefore, there is almost no elution of constituent components and the product has a long life. In addition, the ion-sensitive membrane of the present invention has extremely high responsiveness of chloride ions to interfering ions such as bicarbonate ions and phosphate ions that exist in biological fluids such as blood and urine, and therefore has a high ion-selectivity. By using it as an ion-sensitive membrane of an electrode, it is possible to quantify chloride ions in biological fluids such as blood and urine with extremely high accuracy. Furthermore, since the ion-sensitive membrane has a crosslinked structure, it has excellent resistance to organic contamination, and it is possible to stably quantify chlorine ions in biological fluids over a long period of time. Generally, the organic contamination resistance of an ion-sensitive membrane can be confirmed by the stability of the potential of an aqueous solution containing a specific concentration of chloride ions after immersion in an aqueous solution containing an anionic surfactant. In addition, the selectivity of chlorine ions to fat-soluble anions such as nitrate ions, perchlorate ions, and thiocyanate ions can be improved by allowing a linear alcohol having a carbon number of 10 or more to exist in the ion-sensitive membrane. This allows for more accurate placement of chloride ions in biological fluids. From the above points, the industrial value of the ion-sensitive membrane of the present invention is extremely large.

The ion-selective electrode to which the ion-sensitive membrane obtained by the method of the present invention can be applied may have any known structure without particular limitation. Generally, it is preferable to have a structure in which an internal standard electrode and an internal electrolyte are housed in a container in which at least a portion of the part to be immersed in the sample solution is constituted by the ion-sensitive membrane. For example, a typical embodiment is the structure shown in FIG. 1 above. That is, the ion-selective electrode shown in FIG. 1 has an ion-sensitive membrane 12 attached to the lower surface of an electrode cylinder 11, and an internal electrolyte 13 is filled in the container, and an internal reference electrode 14 is provided. That's what happens. In addition, 15
is an O-ring for liquid sealing.

In the electrode, materials other than the ion-sensitive membrane are not particularly limited, and conventional materials may be used without limitation. For example, the electrode cylinder material may be polyvinyl chloride, polymethyl methacrylate, etc., the internal electrolyte may be a sodium chloride aqueous solution, potassium chloride aqueous solution, etc., and the internal reference electrode may be a conductive material such as platinum, gold, carbon graphite, etc. Slightly soluble metal chlorides such as silver-silver chloride and mercury-mercury chloride are used.

The ion-selective electrode to which the ion-sensitive membrane obtained by the method of the present invention can be applied is not limited to the structure shown in FIG. 1, but may have any structure as long as it has the ion-sensitive membrane. Examples of other suitable ion-selective electrodes include ion-selective electrodes formed by pasting the ion-sensitive membrane on a conductor such as gold, platinum, or graphite, or an ion conductor such as silver chloride or mercury chloride. sexual electrodes, etc.

Further, an ion-selective electrode using such an ion-sensitive membrane can be used in a known manner.

For example, the basic usage mode is as shown in FIG. 2 described above. That is, the ion-selective electrode 21 is immersed together with the salt bridge 22 in the sample solution 23, and the other end of the salt bridge is immersed together with the comparison electrode 24 in the saturated potassium chloride solution 26.

Generally known reference electrodes are employed as the reference electrode, and examples of publicly used reference electrodes include calomel electrode,
These include silver-silver chloride electrodes, platinum plates, carbon graphite, etc.

Examples are given below to further specifically explain the present invention, but the present invention is not limited to these Examples.

In the examples of the present invention, the molar fraction of the unit represented by [II or [I]] in the ion exchange polymer is the hydrophobic unit fraction, and the molar fraction of the unit represented by [II[] The mole fraction is abbreviated as methytoluniy).

Production Example 1 5 mmol of the monomer shown in Table 1. 7.5 mmol of N-methylolacrylamide and 5 mg of azobisiso7thyronitrile were placed in a test tube along with 10 ml of benzene and 10 ml of ethanol. After placing the inside of the test tube under a nitrogen atmosphere, the test tube was sealed tightly and polymerized at 50°C for 48 hours. The contents were poured into 500 ml of methanol and the resulting precipitate was collected by filtration.

The solid material is first dried as an ion exchange polymer by drying under reduced pressure.
The amounts shown in the table were obtained. The unit fraction of each unit in the ion exchange polymer was determined by elemental analysis. The results are summarized in Table 1.

Production Example 2 Monomers shown in Table 2 in amounts shown in Table 2, N-methylolacrylamide 10 mmol, benzoyl peroxide 7
mg was placed in a test tube along with 30 ml of chloroform and 5 ml of methanol. After placing the inside of the test tube under a nitrogen atmosphere, the test tube was sealed tightly and polymerized at 60°C for 30 hours. The contents were poured into 500 ml of methanol and the resulting precipitate was collected by filtration. By drying under reduced pressure, a solid substance as an ion exchange polymer was obtained in the amount shown in Table 2. The unit fraction of each unit in the ion exchange polymer was determined by elemental analysis. The results are summarized in Table 2.

Manufacturing example 3 unit The fraction was calculated.

Table 3 summarizes the results. 10 mmol of the monomer shown below, Shown below.

10 mmol of N-methylolacrylamide, 10 mmol of the salt shown in Table 3, and 2 mg of azobisisobutyronitrile were dissolved in a benzene-ethanol mixed solvent (1:1).
．． (weight ratio) was placed in a test tube together with 30 ml. After placing the inside of the test tube under a nitrogen atmosphere, the test tube was sealed tightly and polymerized at 65°C for 30 hours. The contents were poured into 800 ml of methanol and the resulting precipitate was collected by filtration. By drying under reduced pressure,
A solid substance as an ion-exchangeable polymer was obtained in the amount shown in Table 3. Each unit in the ion-exchangeable polymer was determined by elemental analysis Table 3 Production Example 4 10 mmol of the monomer shown in Table 4 and 1 acrylamide
0 mmol and 2 mg of azobisisobutyronitrile in a benzene-ethanol mixed solvent (1:1. weight ratio) 4
0ml into a test tube. After placing the inside of the test tube under a nitrogen atmosphere, the test tube was sealed tightly and polymerized at 45° C. for 60 hours. The contents were poured into 10,100 O acetonitrile and the resulting precipitate was collected by filtration. By drying under reduced pressure, a solid polymer was obtained in the amount shown in Table 4. The unit fraction of each unit in the polymer was determined by elemental analysis. The results are summarized in Table 4.

Film Formation Example 1 500 mg of the ion exchange polymers Nos. 011 to 41 produced in Production Examples 1 to 3 were dissolved in 10 ml of chloroform and cast into a petri dish made of polytetrafluoroethylene (hereinafter abbreviated as PTFE).

Chloroform was evaporated at 60° C. and atmospheric pressure to obtain a uniform, transparent film. Each of the obtained film-like substances was
After being attached to an electrode as shown in the figure, it was heat-treated under the conditions shown in Table 5. After cooling, a crosslinking reaction was carried out under the conditions shown in Table 5. The numbers and solubility of the obtained membranes in chloroform are summarized in Table 5.

As can be seen from Table 5, the ion-sensitive membrane obtained was insoluble in chloroform, indicating that a crosslinking reaction had occurred.

Film Formation Example 2 Production No. 42-63 Polymer 50 produced in Production Example 4
0 g was dissolved in 10 ml of dichloroform and cast in a PTFE Petri dish. Chloroform was evaporated at 60° C. and atmospheric pressure to obtain a uniform, transparent film. After each of the obtained membranes was attached to an electrode as shown in Fig. 1,
Heat treatment was performed at 90°C for 5 minutes in LM-NaCl solution. After cooling, methylolization was performed under the conditions shown in Table 6. Table 6 shows the methylol unit fraction obtained by elemental analysis. Subsequently, a crosslinking reaction was carried out under the conditions shown in Table 6. The numbers and solubility of the obtained membranes in chloroform are summarized in Table 6.

Table 6 As can be seen from Table 6, methylol groups were introduced into the obtained ion-sensitive 2 film by formaldehyde treatment, and a crosslinking reaction occurred.

Example 1 Using the ion-sensitive membranes No. 011 to 64 obtained in Film Formation Example 1.2 and the apparatus shown in FIG. 2, the relationship between the concentration and potential difference at room temperature of various anions was measured. . From the results obtained, a known method [G, J, Moody, J,
Written by D. Thomas.

Shin Munemori 9th, translated by Kazuo Shiro, “Ion Selective Electrode”, Kyoritsu Shuppan,
The chloride ion selectivity coefficient for each anion was determined by the method described on page 18 (1977). The results are summarized in Table 7. Incidentally, as the Hikyo membrane 1, an ion-sensitive membrane [Analytic
al Chemistry, 56゜535-538 (1
The selectivity coefficient for chlorine ions was determined in a similar manner for the membrane described in 984), and the selectivity coefficient for chlorine ions was determined in the same manner for a commercially available ion exchange membrane (trade name: Neocepta AC3, manufactured by Tokuyama Soda Co., Ltd.) as Comparative Membrane 2. Table 7 also shows the selectivity coefficients for chlorine ions.

The ion selectivity coefficient in this example indicates that the smaller the value, the better the selectivity of the ion-sensitive membrane for chlorine ions. As can be seen from Table 7, the ion-selective electrode using the ion-sensitive membrane of the present invention is effective in reducing chloride ions to Wii acid ions, phosphate ions, acetate ions, bicarbonate ions, and iodine ions present in biological fluids. It has excellent selectivity and is suitable for measuring chloride ion concentration in biological fluids.

Furthermore, in order to examine the organic contamination resistance of the obtained ion-sensitive membrane, a contamination test with sodium dodecyl sulfate (hereinafter abbreviated as SDS) was conducted. That is, using the apparatus shown in FIG. 2, the potential difference is measured when the following solutions are used as samples in order.

1.100mM sodium chloride aqueous solution2,0. 1
Weight% SDS aqueous solution 3.100mM sodium chloride aqueous solution At this time, the potential difference value of 3 is ±1 compared to the potential difference value of 1.
The time required for the voltage to fall within mV was measured and used as an index of contamination resistance. Generally, when an ion-sensitive membrane adsorbs SDS, the value of the potential difference becomes smaller. Subsequently, by immersion in a sodium chloride solution, the adsorbed SDS is gradually redissolved in the solution, so that the potential difference returns to its original value. It can be said that the shorter the redissolution time, the better the organic contamination resistance of the ion-sensitive membrane.

Table 8 shows the results of the SDS contamination test of the obtained ion-sensitive membrane. For comparison, a similar test was conducted on an ion-sensitive membrane of the same composition without crosslinking reaction, and the results are also shown in Table 8.

As can be seen from Table 8, the ion-sensitive membrane of the present invention has significantly improved resistance to organic contamination by cross-linking, and is an ion-selective electrode that can accurately measure samples such as biological fluids over a long period of time. It is suitable as an ion-sensitive membrane.

Film Formation Example 3 500 layers of ion exchange polymers of Production Nos. 1 to 41 produced in Production Examples 1 to 3 and the linear alcohols shown in Table 9 in the amounts shown in Table 9 were dissolved in 10 ml of chloroform. P.T.
The mixture was cast into an FE Petri dish.

Chloroform was evaporated at 60° C. and atmospheric pressure to obtain a uniform, transparent film. The obtained ion-sensitive membranes were each heat-treated in a trench attached to an electrode as shown in FIG. 1 under the conditions shown in Table 10. After cooling, a crosslinking reaction was carried out under the conditions shown in Table 10. Table 10 summarizes the numbers and solubility of the obtained membranes in chloroform.

Table 9 Table 9 (Continued) Table 10 (Continued) Table 10 As can be seen from Table 10, the obtained ion-sensitive membrane was insoluble in chloroform, indicating that a crosslinking reaction was occurring. .

Film Formation Example 4 Production No. 42-63 Polymer 50 produced in Production Example 4
0 mg and 300 mg of stearyl alcohol were dissolved in 10 ml of chloroform and cast in a PTFE petri dish. Chloroform was evaporated at 60'C and atmospheric pressure to obtain a uniform and transparent film. Each of the obtained membranes was attached to an electrode as shown in FIG. 1, and then heated at 90''C in a 1M NaCl solution.

Heat treatment was performed for 5 minutes. After cooling, methylolization was performed under the conditions shown in Table 11. Table 11 shows the methylol unit fraction obtained by elemental analysis.

Subsequently, a crosslinking reaction was carried out under the conditions shown in Table 11.

Table 11 shows the numbers and solubility of the obtained membranes in chloroform.

As can be seen from Table 11, methylol groups were introduced into the obtained ion-sensitive membrane by formaldehyde treatment, and a crosslinking reaction occurred.

Example 2 Using the ion-sensitive membranes with membrane numbers 65 to 128 obtained in Film Formation Example 3.4, the relationship between the concentration and potential difference at room temperature was determined for various anions using the apparatus shown in FIG. It was measured. From the obtained results, the chloride ion selectivity coefficient for each anion was determined in the same manner as in Example 1. The results are shown in Table 12.

As can be seen from Table 12, by incorporating a linear alcohol into the ion-sensitive membrane of the present invention, the selectivity of chloride ions to fat-soluble anions such as thiocyanate ions, perchlorate ions, and nitrate ions is significantly improved. It is suitable for measuring chloride ion concentration in biological fluids.

Table 13 shows the results of the SDS contamination test of the obtained ion-sensitive membrane obtained in the same manner as in Example 1.

For comparison, a similar test was conducted on an ion-sensitive membrane of the same composition without crosslinking reaction, and the results are also shown in Table 13.

As can be seen from Table 13 in the back of Table 13, the ion-sensitive membrane of the present invention has significantly improved resistance to organic contamination through cross-linking reaction, and can be used to accurately measure samples such as biological fluids over long periods of time. It is suitable as an ion-sensitive membrane for selective electrodes.

Example 3 Using the apparatus shown in FIG. 2 using membrane No. 64, 10
Reference electrode (calomel electrode) at 20°C using a sodium chloride aqueous solution as a sample solution in the range of -4M to 10-IM.
and the potential difference between the ion-selective electrode and the ion-selective electrode were measured. The relationship between the obtained potential difference and the chloride ion concentration of the sample solution is shown in Table 14 and FIG. As can be seen from FIG. 3, the ion-selective electrode using the ion-sensitive membrane of the present invention ranges from 10-'M to 10-'M.
-'M shows a linear response. Further, at this time, the potential gradient was 58 V/decade. This value is Ne!
Calculated value 59 mV/decade from the Renst equation
It is in good agreement with From this result, it is clear that the ion-sensitive membrane of the present invention has sufficient sensitivity to chlorine ions.

Table 14 Example 6 Using membrane No. 64 and the apparatus shown in FIG. 2, the concentration of sodium chloride in the sample solution was adjusted to 1. 2mM to 3.3m
Table 15 shows the difference in output potential when suddenly changed to M. Further, FIG. 4 shows the relationship between the concentration of sodium chloride and the output potential difference. As can be seen from Figure 4, the ion-selective electrode using the ion-sensitive membrane of the present invention has a 98% response of 4.
Within seconds, rapid measurement is possible. Further, even after repeating the above measurement 500 times, almost no change in the output potential difference was observed.

Table 15 Application examples Membrane No. 115-1 obtained in Example 4 described above
The ion-sensitive membrane No. 52 was immersed in water at 90° C. for 10 minutes and then attached to the electrode as shown in FIG.

Using this and the apparatus shown in FIG. 2, the output potential was measured when 1 mM and 4 mM sodium chloride aqueous solutions were used as sample solutions. A calibration curve of chloride ion concentration and output potential was created from the measured values. On the other hand, the output potential was measured using an aqueous solution containing 3mM of sodium chloride, 1mM of sodium hydrogen carbonate, 1mM of sodium hydrogen phosphate, 0.005mM of sodium nitrate, and 10mM of sodium sulfate as a test solution.

The obtained values were substituted into the calibration curve to determine the chloride ion concentration. The results are shown in Table 16. The chloride ion concentration was determined in the same manner for Comparative Film 1.2. The results are also shown in Table 16.

As can be seen from Table 16, the measured values obtained using the ion-sensitive membrane of the present invention are in good agreement with the actual chloride ion concentration of 3mM in the test solution, and It is clear that the selective electrode can accurately measure chloride ion concentration in solutions containing various anions.

Table 17

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the structure of an example of an ion-selective electrode using the ion-sensitive membrane of the present invention. FIG. 2 is an explanatory diagram of an apparatus for measuring a potential difference using the ion-selective electrode of FIG. FIG. 3 is a diagram showing the relationship between chloride ion concentration and potential difference measured in Example 1. FIG. 4 is a diagram showing the response speed of the ion-selective electrode of the present invention measured in Example 3. Each number in FIG. 1 and FIG. 2 indicates the following content. DESCRIPTION OF SYMBOLS 11... Electrode cylinder body, 12... Ion-sensitive membrane, 13.
・・Internal electrolyte, 14・Internal reference electrode, 15・0 ring, 21・
...Ion selective electrode, 22...Salt bridge, 23...Sample solution, 24...Reference electrode, 25...Electrometer 26...Saturated potassium chloride aqueous solution, 27...Recorder patent Applicant: Tokuyama Soda Co., Ltd. Figure 3

Claims (2)

[Claims] (1) (i) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (However, Y is a group selected from hydrogen, an alkyl group, a cyano group, is a halogen ion or an atomic group that forms an anion, Z is ▲ there are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ mathematical formulas, chemical formulas,
There are tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ Mathematical formulas, chemical formulas,
There are tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲Mathematical formulas, chemical formulas,
There are tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, -COOR^3-
, -OCOR^3-, -CONHR^3-, and -NHC
OR^3- (However, R^3 has ▲ mathematical formulas, chemical formulas, tables, etc. ▼, ▲ has mathematical formulas, chemical formulas, tables, etc. ▼, or ▲ has mathematical formulas, chemical formulas, tables, etc. ▼, (However, m is (an integer of 1 to 10), n is an integer of 1 to 10), R^1 and R^2 are an alkyl group having 5 or less carbon atoms, a halogenated alkyl group, a hydroxyalkyl group, and a benzyl group. A is a nonionic group having either two or three long-chain hydrophobic groups, or one straight-chain hydrophobic group containing a rigid part in the chain; It is a valent group, and B^1 and B^2 represent the same or different types of nonionic monovalent long-chain hydrophobic groups. ) contains 10 mol% or more of a unit represented by (ii) general formula ▲ mathematical formula, chemical formula, table, etc. ▼ (However, Y is a group selected from hydrogen, an alkyl group, a cyano group, and R^4 is 10 mol of the unit represented by hydrogen or a group selected from alkyl groups having 5 or less carbon atoms.
A method for producing an ion-sensitive membrane, which comprises forming a linear polymer containing % of the linear polymer into a membrane, and then crosslinking the linear polymer. (2) (i) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (However, Y is a group selected from hydrogen, an alkyl group, a cyano group, is a halogen ion or an atomic group that forms an anion, Z is ▲ there are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ mathematical formulas, chemical formulas,
There are tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ Mathematical formulas, chemical formulas,
There are tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲Mathematical formulas, chemical formulas,
There are tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, -COOR^3-
, -OCOR^3-, -CONHR^3-, and -NHC
OR^3- (However, R^3 has ▲ mathematical formulas, chemical formulas, tables, etc. ▼, ▲ has mathematical formulas, chemical formulas, tables, etc. ▼, or ▲ has mathematical formulas, chemical formulas, tables, etc. ▼, (However, m is (an integer of 1 to 10), n is an integer of 1 to 10), R^1 and R^2 are an alkyl group having 5 or less carbon atoms, a halogenated alkyl group, a hydroxyalkyl group, and a benzyl group. A is a nonionic group having either two or three long-chain hydrophobic groups, or one straight-chain hydrophobic group containing a rigid part in the chain; It is a valent group, and B^1 and B^2 represent the same or different types of nonionic monovalent long-chain hydrophobic groups. ) contains 10 to 90 mol% or more of a unit represented by (ii) general formula ▲ mathematical formula, chemical formula, table, etc. ▼ (However, Y is a group selected from hydrogen, an alkyl group, a cyano group, R^ 4 represents a group selected from hydrogen or an alkyl group having 5 or less carbon atoms.
10 to 200 wt% based on the linear polymer containing mol%
1. A method for producing an ion-sensitive membrane, which comprises forming a composition containing a linear alcohol having 10 or more carbon atoms into a film shape, and then crosslinking the linear polymer.