JP2007191581A - Method for forming polymer coating film and ion exchanger prepared thereby - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for forming a polymer coating film which, when applied to a particulate carrier, can form a carrier/polymer coating film composite with no or markedly suppressed agglomeration of the particulate carrier. <P>SOLUTION: The method for forming the polymer coating film comprises the step of allowing a mixture comprising (a) a water-soluble polymer having unsaturated groups in the molecule or an aqueous solution thereof, (b) an organic solvent capable of forming an azeotrope with water, and desirably (c) an organic solvent miscible with water to be present on the surface of a carrier and distillatively removing the solvent to coat the surface of the carrier with a polymer of a reduced water content. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for forming a polymer film, in particular, a method for forming a polymer film having a structure having characteristic functional groups at a high density, a method for producing a carrier-polymer film composite, and these methods. The present invention relates to a polymer coating and a carrier-polymer coating composite. The carrier-polymer coating complex according to the present invention is a weakly acidic cation exchanger used for cation chromatography capable of simultaneously measuring monovalent and divalent cations, particularly a column packing material packed in a separation column. As particularly useful.

  As a filler for cation chromatography capable of simultaneously measuring monovalent and divalent cations, a film of poly (butadiene-maleic acid) (hereinafter sometimes referred to as PBDMA) was formed on porous silica gel. Thereafter, there is a weak acid cation exchanger using a weak acid cation exchanger produced by heating at 180 ° C. for 4 hours (see Non-Patent Document 1).

  However, the weakly acidic cation exchanger produced by this method has a problem that the adhesion between the silica gel carrier and the resin produced from the PBDMA coating is not sufficient, and the reproducibility of the analysis results is poor.

  As a method for solving this problem, a weakly acidic cation exchange composition comprising a crosslinked copolymer of an unsaturated carboxylic acid and unsaturated carboxylic acid anhydride diene monomer copolymer and a vinyl compound is coated. A characteristically weakly acidic cation exchanger has been proposed (see Patent Document 1). In this method, when a film is formed on the surface of the spherical fine particle carrier, a compound having a vinyl group as a functional group is allowed to coexist to produce a PBDMA copolymer crosslinked product at a high temperature, thereby improving durability.

  In the production method of the filler according to these two reports, it is necessary to heat the fine particles containing an organic substance to a high temperature at the time of polymerization, which is not an industrially suitable production method.

  Patent Document 2 proposes a filler for cation chromatography in which the surface of a porous carrier is coated with a cured product of a polyfunctional carboxylic acid compound and a polyfunctional epoxy compound. In this report, it is reported that a column with improved durability can be obtained, but the structure containing the functional group contains an ester bond, and there may be inconveniences such as degradation due to hydrolysis.

  Moreover, all of these proposals are not aimed at improving the separation of monovalent cations, particularly the separation of sodium ions and ammonium ions, and the separation of these cations has not been sufficient.

  Apart from this, there have been reported examples aimed at improving the separation of sodium ions and ammonium ions (see Patent Documents 3 and 4). Here, the introduction of a functional group having a crown ether or a similar structure into the porous organic polymer particles has been shown to improve the separation of sodium ions and ammonium ions, particularly by delaying the elution of potassium and ammonium. ing. Although this column fulfills its purpose sufficiently, it has the disadvantage that the peak shape of potassium is deteriorated and a solution containing an organic solvent must be used as an eluent.

  Furthermore, these reports show examples in which a copolymer made of maleic anhydride and ethyl vinyl ether is grafted onto a polystyrene base material in the examples. In general, the method using graft polymerization may certainly introduce a large amount of functional groups. However, most of the copolymer polymer chains introduced by this method spread in a direction perpendicular to the substrate surface. This increases the film thickness of the site containing the functional group on the carrier. For this reason, when the amount of functional groups introduced is increased, the column packing pressure is increased or the separation efficiency of the column is decreased.

  As a column used in the suppressor system, the trade name Ionpac CS16 is commercially available from Dionex. This is packed with a packing for cation chromatography having a carboxyl group / phosphonic acid group, and the separation of monovalent cations is improved, and in particular, the separation of sodium ions and ammonium ions is improved. However, this column was a suppressor system column using an eluent with a high concentration of 30 mmol methanesulfonic acid.

  In such a background, there is a demand for a weakly acidic cation exchanger that can be used for simultaneous analysis of monovalent and divalent cations, which can highly separate monovalent cations under an eluent condition of an appropriate concentration.

  In general, a filler having a carboxyl group is used as a filler for cation chromatography for simultaneous monovalent and divalent analysis. The appropriate carboxyl group is 500 μeq / g to 3000 μeq / g. This is because if 500 μeq / g or less, sufficient separation is not given, and if it is 3000 μeq / g or more, elution of ions becomes too slow. In order to improve ion separation, the amount of substituents to be introduced should be increased as much as possible. However, the conventional substituent introduction methods often result in an influence on the shape of the carrier, and as a result, the separation is deteriorated.

  As an example of a reaction between a polymer compound having a double bond and maleic anhydride, a report is made that a compound obtained by further reacting a butadiene copolymer with maleic anhydride is used for electrophoretic coating. There are reports on aqueous dispersions for photographic coating solutions obtained by further reacting a compound obtained by reacting maleic acid (see, for example, Patent Documents 5 and 6). However, the production example as a weakly acidic cation exchanger is only the example described in Patent Document 2.

  Patent Document 7 describes a method for producing a weakly acidic cation exchanger. A column packed with a weakly acidic cation exchanger by this method can highly separate monovalent cations. However, when produced using fine carrier particles, the carrier particles may aggregate. is there. For this reason, in order to further improve the number of theoretical plates, there is a method for obtaining a higher-performance ion exchanger that can have a functional group at a high concentration on a fine carrier and that does not cause aggregation or is remarkably suppressed. It was sought after.

Chromatographia, 1987, Vol. 23, No. 7, p. 465-472 JP-A-5-96184 JP-A-8-257419 US Pat. No. 5,968,363 US Pat. No. 5,875,994 Japanese Patent Publication No.49-4059 Japanese Patent Publication No. 60-21372 Patent Publication 2004-97985

  An object of the present invention is to provide a method for forming a polymer film that can form a carrier-polymer film complex in which aggregation does not occur or is remarkably suppressed when applied to a particulate carrier. In particular, providing a method for producing a high-performance column packing material (especially an ion exchanger) that can have a high concentration of functional groups on a fine carrier and can realize a high number of theoretical plates when packed in a chromatography column. Is one of the issues. Furthermore, a weakly acidic cation exchanger is produced under mild conditions, a stronger weakly acidic cation exchange membrane is produced, monovalent cations can be highly separated, and monovalent and divalent cations can be separated. One of the problems is to produce a weakly acidic cation exchanger that can be analyzed at the same time, and to provide a chromatography column using the ion exchanger.

  As a result of studies to solve the above problems, the present inventors have obtained a mixture containing (a) a water-soluble polymer having an unsaturated group in the molecule or an aqueous solution thereof and (b) an organic solvent azeotropic with water. There is no agglomeration even when a fine particle carrier is used by adopting a method for forming a polymer film including a step of coating a carrier surface with a polymer having a reduced water content by removing the solvent by removing the solvent. In particular, in a solvent in which the polymer is not dissolved, crosslinking is performed in the presence of a functional group (for example, a carboxylic acid group) and a molecule containing unsaturation, so that the functional group can be concentrated at a high concentration. It has been found that it can be introduced under mild conditions and various column fillers (eg, weakly acidic cation exchangers) can be produced. Further, when ethylene-α, β-unsaturated dibasic acid is used as a molecule containing the functional group and unsaturation in the solvent, ethylene-α, β-unsaturated dibasic acid reacts and becomes stronger. It has been found that a film can be formed. Further, the weakly acidic cation exchanger obtained by this method was found to highly separate monovalent cations when packed in a column, and the present invention was completed.

  That is, the present invention comprises the following method for forming a polymer coating, a polymer coating produced by this method, a carrier-polymer coating complex having a polymer coating on its surface, and the carrier-polymer coating complex. Column packing material, in particular ion exchanger (especially weakly acidic cation exchanger), and separation column characterized by using this column packing material, in particular ion chromatography using ion exchanger Column (especially a column for weak acid cation chromatography).

1. (a) A mixture containing a water-soluble polymer having an unsaturated group in the molecule or an aqueous solution thereof and (b) an organic solvent azeotropic with water is present on the surface of the carrier, and the solvent is distilled off to reduce the water content. A method for forming a polymer film, comprising the step of coating a carrier surface with a reduced polymer.
2. 2. The method for forming a polymer film according to 1 above, further comprising a step of performing a crosslinking reaction of the polymer.
3. 3. The method for forming a polymer film as described in 2 above, wherein the crosslinking reaction is carried out in a solvent in which the polymer is not dissolved.
4). 4. The method for forming a polymer film according to 2 or 3 above, wherein at the time of performing a crosslinking reaction, at least one functional group and a molecule having one unsaturated bond coexist, and the functional group is introduced into the polymer film.
5). 5. The method for forming a polymer film according to 4, wherein the functional group is at least one functional group selected from the group consisting of a carboxylic acid group, a sulfonic acid group, and an amino group.
6). 6. The method for forming a polymer film as described in 5 above, wherein the molecule for introducing a functional group is ethylene-α, β-unsaturated dibasic acid.
7). 7. The method for forming a polymer film as described in 6 above, wherein the ethylene-α, β-unsaturated dibasic acid is maleic anhydride.
8). 8. The method for forming a polymer film according to any one of 1 to 7, wherein the water-soluble polymer having an unsaturated group in the molecule is an unsaturated carboxylic acid-diene monomer copolymer.
9. 9. The method for forming a polymer film according to any one of 1 to 8, wherein the unsaturated carboxylic acid-diene monomer copolymer is poly (butadiene-maleic acid).
10. The polymer according to any one of 1 to 9 above, wherein the organic solvent azeotropic with water is at least one selected from the group consisting of aromatic hydrocarbons, alcohols, ketones, esters, and ethers. Method for forming a film.
11. 11. The method for forming a polymer film as described in 10 above, wherein the organic solvent azeotropic with water is at least one selected from the group consisting of benzene, toluene, xylene, methyl ethyl ketone, ethyl acetate and dioxane.
12 12. The method for forming a polymer film as described in 11 above, wherein the organic solvent azeotropic with water is toluene.
13. (A) a mixture comprising a water-soluble polymer having an unsaturated group in the molecule or an aqueous solution thereof and (b) an organic solvent azeotroped with water, further comprising (c) an organic solvent miscible with water The formation method of the polymer film in any one of 1-12.
14 14. The method for forming a polymer film as described in 13 above, wherein the organic solvent miscible with water is at least one selected from alcohols, ketones, esters, ethers and nitriles.
15. 15. The method for forming a polymer film according to 14, wherein the organic solvent miscible with water is at least one selected from the group consisting of methanol, ethanol, acetone, ethyl acetate, dioxane, and acetonitrile.
16. 16. The method for forming a polymer film as described in 15 above, wherein the organic solvent miscible with water is acetone.
17. 17. The method for forming a polymer film according to any one of 1 to 16, wherein the carrier is an inorganic porous carrier or a polymer gel.
18. 18. The method for forming a polymer film as described in 17 above, wherein the inorganic porous carrier is silica gel.
19. 18. The method for forming a polymer film as described in 17 above, wherein the polymer gel is polyvinyl alcohol gel.
20. 20. The method for forming a polymer film according to any one of 17 to 19, wherein the carrier is spherical porous particles having a weight average particle diameter of 1 to 100 μm.
21. The polymer film manufactured by the method in any one of said 1-20.
22. 21. A carrier-polymer film composite having a polymer film produced by any one of the methods 1 to 20 on its surface.
23. 23. The carrier-polymer film composite as described in 22 above, which is a column filler.
24. A polymer film having at least one functional group selected from the group consisting of a carboxylic acid group, a sulfonic acid group, and an amino group introduced on its surface, a weakly acidic cation exchanger, a strongly acidic cation exchanger, or 24. The carrier-polymer film composite as described in 22 or 23 above, which is an anion exchanger.
25. 25. The weakly acidic cation exchanger as described in 24 above, wherein the introduced functional group is a carboxylic acid group.
26. 25. An ion chromatography column using the ion exchanger as described in 24 above.
27. 26. A column for weak acid cation chromatography using the weak acid cation exchanger as described in 25 above.

  According to the method of the present invention, a polymer film can be formed while there is no aggregation even when a fine particle carrier is used or the aggregation is remarkably suppressed. Further, it is possible to produce a high-performance column filler, particularly an ion exchanger (particularly a weakly acidic cation exchanger) under relatively mild conditions below the boiling point of the solvent. Furthermore, when ethylene-α, β-unsaturated dibasic acid is dissolved, ethylene-α, β-unsaturated dibasic acid reacts to form a stronger film. The weak ion exchanger obtained by this method can highly separate monovalent cations when packed in a column.

Hereinafter, the present invention will be described in more detail.
In the method for forming a polymer film of the present invention, a mixture containing (a) a water-soluble polymer having an unsaturated group in the molecule or an aqueous solution thereof and (b) an organic solvent azeotropic with water is present on the surface of the carrier. And a step of coating the carrier surface with a polymer having a reduced water content by distilling off the solvent.

In the conventionally proposed method, the use of such a process for the formation of the polymer film has not been disclosed. The present inventors have found that the use of this step improves the coating state with the polymer, and can prevent the condensation of the carrier, which frequently occurs in conventional methods not including this step.
Aggregation of the carrier leads to an increase in the particle size distribution of the carrier. It is generally known that when a carrier having a wide particle size distribution is packed in an analytical column, the number of theoretical plates is lower than when a carrier having a narrow particle size distribution is packed in an analytical column. For this reason, by using this step, when used in the final analytical column, the number of theoretical plates is improved, and a high performance column can be obtained.
Furthermore, when maleic anhydride is used in the subsequent cross-linking step, the reaction in the subsequent step may be hindered by the reaction and change of maleic anhydride due to residual moisture. It can also be prevented.

The water-soluble polymer having an unsaturated group in the molecule used in the present invention is one in which the unsaturated group can react with a radical or the like and can form a film on a carrier. Not limited. The water-soluble polymer may be synthesized or used as a commercial product. In general, commercial products are sold as aqueous solutions. Even when it is synthesized and used, its viscosity may be adjusted as an aqueous solution as required. In any case, since the water-soluble polymer easily absorbs moisture in the atmosphere, it contains a certain amount of water during use. The concentration in the case of an aqueous solution may be adjusted to such an extent that the surface of the carrier can be sufficiently covered with the water-soluble polymer. Usually, however, the water-soluble polymer has a relatively high viscosity. An aqueous solution of a degree is preferred.
The unsaturated group is typically an ethylenic carbon-carbon double bond. As will be described later, in the present invention, it is preferable to produce a uniform film by a crosslinking reaction, and therefore it is preferable to have a large number of double bonds. In that respect, a polymer or copolymer of a divinyl compound or a diene, or a polymer in which a double bond is introduced by reaction is preferable.

  For example, an unsaturated carboxylic acid diene monomer copolymer is used. Poly (butadiene-maleic acid) (hereinafter sometimes referred to as PBDMA) is preferable. These can be used alone or as a mixture of a plurality. PBDMA is generally commercially available (for example, from Polyscience).

The organic solvent azeotroped with water (hereinafter also simply referred to as “azeotropic solvent”) used in the present invention is used to remove water from the water-soluble polymer or an aqueous solution thereof. In some cases, it functions as a solvent.
As the azeotropic solvent, when performing the crosslinking reaction described later, it is sufficient to select a solvent according to the desired purpose without adversely affecting the crosslinking reaction. For example, Chemistry Handbook Basic Edition II (The Chemical Society of Japan (Revised) Examples include aromatic hydrocarbons, alcohols, ketones, esters, ethers, and the like, which include azeotropic organic solvents with water described in 5th edition (2004), Maruzen). Examples of aromatic hydrocarbons include benzene, toluene, xylene, ethylbenzene, cumene and the like. Examples of alcohols include ethanol, 1-propanol, isopropyl alcohol, 1-butanol, 2-butanol, 1-pentanol, 1-octanol, benzyl alcohol and the like. Examples of ketones include methyl ethyl ketone and cyclohexanone. Examples of esters include methyl acetate, ethyl acetate, propyl acetate, butyl acetate, butyl formate, ethyl benzoate, and ethyl propionate. Examples of ethers include 1,4-dioxane, 1,2-diethoxyethane, diisopropyl ether, and the like, but any type of compound is not limited to those exemplified here. Of these, toluene and xylene are preferable in consideration of economy.

As described above, the water-soluble polymer has a certain water content at the beginning of use, but in the method for forming a polymer film of the present invention, the water-soluble polymer or an aqueous solution thereof and an organic solvent azeotropic with water are used. A mixture containing is present on the surface of the carrier, and the solvent is distilled off to coat the surface of the carrier with a polymer having a reduced water content.
The degree of water content reduction may vary depending on the purpose, but is typically 3% by mass or less, preferably 1000 ppm (wt) or less. When the water content exceeds 3% by mass, it is difficult to avoid aggregation when particles are used as a carrier. The lower limit value of the water content finally becomes the saturated solubility of water in the solvent used for azeotropy. For example, in the case of toluene, it is about 300 ppm. However, in practice, the amount of water does not have to be reduced so far, and may be between the value determined by the saturation solubility and the upper limit.

  In addition, a support | carrier is not specifically limited, A material and a shape will not be ask | required if it can coat | cover with a water-soluble polymer. However, when the present invention is applied to a particulate carrier, the surface thereof can be coated with a water-soluble polymer while preventing the aggregation of the particulates, and can be suitably applied to such a carrier. Preferred examples of the particulate carrier and specific applications thereof will be described later.

  The amount ratio between the water-soluble polymer and the azeotropic solvent (as described above, the term “organic solvent azeotropic with water” is used hereinafter) is the same as the water content to be adjusted and the azeotropic solvent used. It may vary depending on the azeotropic composition of the boiling solvent. The azeotropic composition of the above solvents with water is generally known (see, for example, “Chemical Handbook Fundamental II” above), and the amount of azeotropic solvent required for water-soluble polymers can be determined by those skilled in the art. If so, it can be easily obtained. For example, when the azeotropic solvent is toluene, the azeotropic composition is water: toluene = 19.91: 80.09 (85 ° C., wt%). When calculated from this, when toluene is used as an azeotropic solvent with respect to 100 g of a 40% by mass water-soluble polymer aqueous solution (that is, a water content of 60 g), it becomes 242 g (theoretical value) or more of toluene. In general, when the azeotropic composition is water: azeotropic solvent = 1: p (mass ratio), {(100−x) / 100} a × p mass with respect to a mass part of the x mass% water-soluble polymer aqueous solution. The part becomes a theoretical value, and an azeotropic solvent higher than the theoretical value is used. The actual amount used is determined so that the water content considering the saturation solubility is within the above range. For example, in toluene, about 242 g (theoretical value) to about 483 g (double amount) may be used with respect to an aqueous solution of a water-soluble polymer (when 40%, 100 g is used). It is possible to use more than twice the amount of toluene, but even if an excessive amount of toluene is used, the effect is not changed and it is not economically advantageous.

  When the azeotropic solvent used is immiscible with water, the mixture containing the water-soluble polymer or an aqueous solution thereof and the azeotropic solvent preferably further contains an organic solvent miscible with water. Examples of the organic solvent miscible with water include alcohols, ketones, esters, ethers, nitriles and the like. Examples of alcohols include methanol, ethanol, isopropyl alcohol and the like. Examples of ketones include acetone and methyl ethyl ketone. Examples of the esters include methyl acetate and ethyl acetate. Examples of ethers include 1,4-dioxane, tetrahydrofuran, dioxolane and the like. In addition to the above, examples of nitriles include acetonitrile and the like, but are not limited thereto. The amount of the organic solvent miscible with water may be equal to or higher than the solubility of water in the organic solvent to be used, but even if an excessive amount is used, the effect is not changed, and this is not economically preferable.

  (a) The operation of allowing a mixture containing a water-soluble polymer having an unsaturated group in the molecule or an aqueous solution thereof and (b) an organic solvent azeotropic with water to exist on the surface of the carrier is, for example, that the carrier is plate-like In some cases, a conventional coating operation may be used, but when the carrier is in the form of particles, it is preferable to carry out by dispersing the particulate carrier in a mixture of (a) and (b). In this case, when the mixture of (a) and (b) further contains (c) an organic solvent miscible with water, (a), (b), (c) and the carrier can be mixed in any order. However, when the organic solvent azeotropic with water is immiscible with water, it is preferable that (a), (c) and the carrier are mixed, and then (b) is added and mixed. In any case, after mixing, it is preferable to disperse the carrier particles in the liquid by ultrasonic vibration or the like.

  Next, the solvent is removed. The removal of the solvent can be performed under normal pressure or under reduced pressure. The specific conditions depend on the type of carrier and azeotropic solvent, and also when an organic solvent miscible with water is used, depending on the type and amount, but usually, distillation at 60 ° C. or lower is preferable. If it is a simple solvent, distillation at 60 ° C. or less is possible at a reduced pressure of about 10 to 500 mmHg.

  By distilling off the azeotropic solvent, water is removed from the water-soluble polymer or its aqueous solution together with the azeotropic solvent, and the carrier surface is coated with the water-soluble polymer having a reduced water content. At this time, the amount of the water-soluble polymer for coating the carrier is not particularly limited. Specifically, depending on the use of the membrane, for example, in the production of the column filler, the amount of the water-soluble polymer is 0.1 to 3 times by weight with respect to the porous spherical fine particles as the carrier. The amount is preferably 0.2 to 1.0 times. If the amount of the water-soluble polymer having an unsaturated bond in the molecule is too small, a coating film is not formed well on the carrier, and if it is too large, aggregation of the coated carrier tends to occur.

  Preferably, the polymer is then subjected to a crosslinking reaction. The crosslinking reaction of the water-soluble polymer having an unsaturated bond in the molecule of the present invention is usually carried out in a solvent, but the polymerization method is not particularly limited. A radical polymerization initiator is preferably used in order to perform the reaction under mild reaction conditions, but either a thermal polymerization initiator or a photopolymerization initiator can be used. In particular, thermal polymerization initiators such as azobis compounds and peroxides are preferred.

  The solvent used in the cross-linking reaction varies depending on the polymerization degree and cross-linking degree of the polymer, but it is preferable to select a solvent that does not dissolve the water-soluble polymer to be used. Here, the “non-dissolving” solvent means a solvent that stays in place without being uniformly dispersed in the short term when the polymer is introduced into a certain solvent.

  In order to confirm this, a water-soluble polymer having an unsaturated bond in the molecule was applied to a suitable carrier such as a slide glass, immersed in the solvent to be verified, heated to the temperature to be used, and 30 minutes passed. What is necessary is just to observe the weight change later. At this time, if the weight loss from before coating is 99% or less of the total coating amount, this polymer can be used. Desirably, the weight loss is 50% or less, particularly 10% or less. In the case of a polymer containing a low molecular weight oligomer, it is also possible to use a method in which only components that do not dissolve are used in the next reaction after the components that are soluble in the solvent are removed in advance.

  Such an organic solvent is not particularly limited as long as it does not dissolve the water-soluble polymer having an unsaturated bond and does not cause a disadvantage in the crosslinking reaction. These solvents may be used alone or in combination. Illustrative examples include, but are not limited to, benzene, toluene, xylene, propylene carbonate, tetrahydrofuran and the like. Moreover, when using further the molecule | numerator which has at least 1 functional group mentioned later and 1 unsaturated bond, it selects from the solvent which melt | dissolves this. In some cases, a molecule having at least one functional group and one unsaturated bond can also serve as a solvent for crosslinking.

  In the cross-linking reaction step of the present invention, a stable film having a new performance in which the functional group is introduced into the molecule by allowing the molecule having at least one functional group and one unsaturated bond to coexist in the solvent. Can be manufactured. The functional group is not particularly limited. For example, for the purpose of imparting ion exchange properties to the polymer film, at least one functional group selected from the group consisting of a carboxylic acid group, a sulfonic acid group, and an amino group is used. it can.

For example, ethylene-α, β-unsaturated dibasic acid can coexist for the purpose of imparting cation exchange properties.
Examples of ethylene-α, β-unsaturated dibasic acids that can be used in the present invention include compounds having carboxy groups at both ends of an ethylenically polymerizable double bond as a substance that imparts weakly acidic cation exchange properties. And derivatives thereof. For example, maleic anhydride, maleic anhydride derivatives (eg, chloromaleic anhydride, citraconic anhydride, 1,2-diethylmaleic anhydride), maleic acid, maleic acid monoester, maleic acid diester, fumaric acid, fumaric acid mono Examples thereof include, but are not limited to, esters and fumaric acid diesters. In particular, maleic anhydride is preferable from the viewpoint of reactivity and industrially.

  Therefore, the solvent used at the time of crosslinking is preferably a solvent that dissolves a molecule having at least one functional group and one unsaturated bond (for example, ethylene-α, β-unsaturated dibasic acid). The solubility of a molecule having at least one functional group and one unsaturated bond in the solvent in the solvent can be determined by the solubility. When represented by the maximum mass of a solute that can be dissolved in 100 g of a solvent, the solubility is desirably 0.01 g / 100 g or more. Usually, it is desirable to select a solvent of 1 g / 100 g or more. The same applies when the molecule having at least one functional group and one unsaturated bond (for example, ethylene-α, β-unsaturated dibasic acid) is a liquid, but in the case of a liquid, the two are not mixed. In some cases, it can be used in a suspended state by stirring.

  In the case of PBDMA (obtained by drying an aqueous solution), examples of a combination of a water-soluble polymer having an unsaturated bond in the molecule and a solvent for crosslinking include toluene and propylene carbonate.

  As a combination including ethylene-α, β-unsaturated dibasic acid which is a molecule having at least one functional group and one unsaturated bond, for example, as an industrially advantageous combination, PBDMA and maleic anhydride And propylene carbonate or PBDMA, maleic anhydride and toluene.

  The amount of the molecule having at least one functional group and one unsaturated bond (eg, ethylene-α, β-unsaturated dibasic acid) is usually added in excess of the amount actually reacted. Taking the column filler as an example, it is used 0.1 to 10 times, more preferably 0.5 to 3.0 times by weight with respect to the porous spherical fine particles.

  The reaction in the case where a molecule having at least one functional group and one unsaturated bond (for example, ethylene-α, β-unsaturated dibasic acid) is added is a condition for reacting with a polymer having an unsaturated bond. There is no particular limitation. The simplest method is to form a copolymer by coexisting a radical initiator. As the radical initiator, any of the commonly used thermal polymerization initiator and photopolymerization initiator can be used. Particularly preferred are azobis compounds and peroxides. Specifically, 2,2′-azobisisobutyronitrile (hereinafter sometimes referred to as AIBN), 2,2-azobis- (2,4-dimethylvaleronitrile), benzoyl peroxide, lauroyl per Examples thereof include, but are not limited to, oxide and dicumyl peroxide.

  In the production according to the present invention, other vinyl compounds may be present in a solvent. The amount is not particularly limited. However, as a vinyl compound, which is easily polymerized alone, when used in a large amount, there is a problem that the formation of the graft polymer is mainly caused and the cross-linking reaction of the polymer having a double bond is difficult to proceed. Furthermore, when manufacturing an ion exchanger, the film thickness of the obtained ion-exchangeable film will become large, or the isolation | separation at the time of filling the column with the obtained ion exchanger will worsen. Considering such a case, the vinyl compound is added in an amount experimentally determined so that the performance according to the purpose can be exhibited.

  In the case of using a molecule having at least one functional group and one unsaturated bond (for example, ethylene-α, β-unsaturated dibasic acid), it is difficult for single polymerization of vinyl compounds to occur and mainly at least 1 A compound known to alternate copolymerize with a molecule having a functional group of 1 and an unsaturated bond (eg, ethylene-α, β-unsaturated dibasic acid, such as maleic anhydride) is at least one The addition is preferably performed in the sense of promoting the crosslinking reaction of the molecule having a functional group and one unsaturated bond. The amount of the vinyl compound at this time is also added in an amount experimentally determined so that the performance according to the purpose can be exhibited.

  The production according to the present invention can include different steps before, after or in between, as long as it includes a step of applying a water-soluble polymer to a carrier and preferably a step of a crosslinking reaction step. For example, after applying a polymer having an unsaturated bond to the carrier in the applying step, for example, a heat treatment may be performed and then a crosslinking reaction step may be performed as a step for improving the properties of the film. Further, after the crosslinking reaction step, a step of converting the obtained film-like substituent into a target form may be performed. For example, when the substituent is in the form of an acid anhydride, it is hydrolyzed under appropriate conditions.

  Since the production according to the present invention can be carried out in an organic solvent without requiring a high temperature, it is possible to use a commonly used apparatus and technique. Furthermore, since the risk is low, industrial adaptation is also possible for porous organic polymer particles and the like. In the case of porous organic polymer particles, a double bond or the like remaining without reacting on the surface of the porous organic polymer particles, a polymer having a double bond, or at least one functional group and one Since the reaction with a molecule having an unsaturated bond (for example, ethylene-α, β-unsaturated dibasic acid) occurs, the membrane also has an advantage of strongly binding to the carrier.

Therefore, according to the present invention, a carrier-polymer film composite is also provided.
As described above, the material and shape of the carrier are not particularly limited, but the carrier-polymer film composite according to the present invention can easily introduce functional groups, and even fine particles are remarkably suppressed or not aggregated. It is particularly useful as a stationary phase (column filler) for chromatography and the like.
Accordingly, as the carrier, polymers such as silica gel, alumina, porous glass, carbon particles, etc., which are inorganic porous carriers, or polystyrene gel, poly (meth) acrylic acid gel, polyvinyl alcohol gel, etc., which are organic porous carriers, are used. A gel is particularly preferably used. The particle diameter is usually 1 to 100 μm, preferably 1 to 50 μm, more preferably 3 to 30 μm in terms of weight average particle diameter, and the pore diameter measured by BET value is desirably in the range of 3 nm to 50 nm.

  The use of the column packing material for chromatography according to the present invention is not particularly limited, but it is particularly useful as an ion exchange column packing material. By selecting a functional group to be introduced into the polymer film, a weak acid cation exchanger, a strong acid It can be a cation exchanger or an anion exchanger.

  Although the principle of the present invention is not clear, it is conceivable that a radical that reacts in a solvent at the time of crosslinking freely moves to facilitate the reaction of a double bond at a position where it easily reacts. In addition, since a decomposition reaction of a radical initiator or the like is performed in a solution by using a solvent, it is a great advantage of the present invention that dangers and complicated handling are eliminated.

In particular, as described above, by reacting ethylene-α, β-unsaturated dibasic acid, monovalent cations can be separated to a high degree, and weakly acidic cation exchange that can be used for simultaneous analysis of monovalent and divalent cations. You can get a body.
Further, in general, ethylene-α, β-unsaturated dibasic acid is difficult to give a high molecular weight polymer by itself, but when used together with a polymer having a double bond, the double bond of the polymer and ethylene-α , β-unsaturated dibasic acid reaction is the main reaction, and weakly acidic functional groups can be introduced into the resulting membrane at high density. For this reason, the weakly acidic cation exchanger which gives a high degree of separation can be obtained.

  Further, polymer particles having the performance as an ion exchanger produced by the method of the present invention, a filler using the same, particularly a filler that is an ion exchanger using a porous polyvinyl alcohol carrier or a porous silica gel carrier is used. A column for cation chromatography can be obtained by packing the column by a usual method.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated further in detail, this invention does not receive any limitation by these description. The analytical instruments and analysis conditions used in the examples are as follows.

-Functional group (carboxyl group) amount Automatic titrator: AT-400 manufactured by Kyoto Electronics Industry Co., Ltd.
<Measurement method>
The weighed sample was dispersed in a 0.1 mmol potassium chloride aqueous solution, and titrated with 0.01N sodium hydroxide using an automatic titrator with pH 8 as the end point.

・ Liquid chromatography (HPLC)
CD detector: ICA-5220 manufactured by Toa Denpa Inc.
Pump: DS-4 manufactured by Shodex ^TM
Column oven: AO-30 manufactured by Shodex ^™
Data processing: 480IIXP made by System Instruments
Eluent: 6mM methanesulfonic acid aqueous solution Column temperature: 40 ° C
Flow rate: 0.8ml / min
Injection volume: 20 μl
Standard measurement samples: Li ⁺ : 0.2 mg / L, Na ⁺ : 1 mg / L, NH ₄ ⁺ : 1 mg / L, K ⁺ : 2 mg / L, Mg ²⁺ : 1 mg / L, Ca ²⁺ : 2 mg / L

-Weight average particle diameter Coulter counter: Beckman Coulter Multisizer 3 (dispersion medium: water)

<Example 1> Example using organic polymer carrier (polyvinyl alcohol gel) (Production of polyvinyl alcohol gel)
A homogeneous mixed liquid consisting of 100 g of vinyl acetate, 180 g of triallyl isocyanurate, 150 g of butyl acetate and 10 g of AIBN and 1400 ml of water in which a small amount of polyvinyl alcohol and sodium phosphate are dissolved are put into a 5 L three-necked flask equipped with a reflux cooling group. Stir for 10 minutes. Next, polymerization was performed at 60 ° C. for 16 hours while stirring under a nitrogen stream to obtain a granular polymer. The polymer was filtered, washed, extracted with acetone, and dried. The obtained polymer was placed in a 5 L three-necked flask equipped with a reflux condenser, a nitrogen inlet tube and a stirrer together with 3 L of a 1N aqueous sodium hydroxide solution, and stirred at 15 ° C. for 20 hours in a nitrogen stream to Then, filtration, washing with water and further drying were carried out. The density of the hydroxyl group of the polyvinyl alcohol polymer obtained by saponification was 2.1 meq / g. Thus, a polyvinyl alcohol polymer (also referred to as polyvinyl alcohol gel) having an average particle diameter of 5 μm was obtained.

(Coating process for carrier)
6.3 g of 40% PBDMA aqueous solution (manufactured by Polyscience) in a 500 ml eggplant flask, 10.0 g of synthesized polyvinyl alcohol gel, 55 g of acetone as an organic solvent miscible with water, and azeotropic with water 120 g of toluene was added as an organic solvent, and ultrasonic waves were applied for 10 minutes to uniformly disperse. After standing for 10 minutes, it was concentrated while rotating at 40 ° C. and 50 mmHg using a rotary evaporator to form a film on the gel surface. The gel on which the film was formed was transferred to a petri dish and air-dried overnight. The weight of the gel at this point was 11.0 g. As a result of visual observation, this gel was uniform and no condensed portion was observed.

(Crosslinking reaction process)
In a 100 ml separate flask, 11.3 g of maleic anhydride and 0.8 g of AIBN were taken and dissolved in 50 g of toluene. The gel on which the film was formed was put here, and it was uniformly dispersed by ultrasonic irradiation. After purging with nitrogen for about 30 seconds, the mixture was heated to 85 ° C. and stirred for 15 hours. The reaction product was filtered, and the filtrate was washed with toluene and pure water. The gel obtained as a filtrate was further hydrolyzed by stirring in a 6 mM methanesulfonic acid aqueous solution at 45 ° C. for 16 hours. The contents were filtered, and the filtrate was thoroughly washed in the order of pure water and acetone and air-dried. In this way, 12.0 g of weakly acidic cation exchanger was obtained.
The amount of the weakly acidic functional group was 2022 μeq / g by an automatic titrator.
The weakly acidic cation exchanger thus obtained was packed in a separation column for liquid chromatography (inner diameter 6.0 mm, length 150 mm), and the standard measurement sample was separated.
The obtained chromatogram is shown in FIG. In FIG. 1, peak 1 is Li ⁺ , peak 2 is Na ⁺ , peak 3 is NH ₄ ⁺ , peak 4 is NH ₄ ⁺ , peak 5 is Mg ²⁺ , and peak 6 is Ca ²⁺ . It can be seen that the peak interval of monovalent cations is widened, and in particular, sodium and ammonium peaks are separated at the baseline. The number of theoretical plates is K ⁺ , which is 11000, indicating excellent separation performance.

<Comparative Example 1> Example using an organic polymer carrier (polyvinyl alcohol gel) (coating step on the carrier)
The same operation as in Example 1 was performed except that toluene was not used. The gel on which the film was formed was transferred to a petri dish and air-dried overnight. The weight of the gel at this point was 13.4 g. As a result of visual observation, the gel was partially condensed.
(Crosslinking reaction process)
A cross-linking reaction was performed in the same manner as in Example 1 using a gel in which a water-soluble polymer was applied to the carrier. In this way, 12.5 g of weakly acidic cation exchanger was obtained.
The amount of the weakly acidic functional group was 2022 μeq / g by an automatic titrator.
The weakly acidic cation exchanger thus obtained was packed in a separation column for liquid chromatography (inner diameter 6.0 mm, length 150 mm), and the standard measurement sample was separated.

The obtained chromatogram is shown in FIG. In FIG. 2, peak 1 is Li ⁺ , peak 2 is Na ⁺ , peak 3 is NH ₄ ⁺ , peak 4 is NH ₄ ⁺ , peak 5 is Mg ²⁺ , and peak 6 is Ca ²⁺ . The peak interval of monovalent cations is widened, and especially the peaks of sodium and ammonium are separated at the baseline, but the number of theoretical plates is K ⁺ , which is 6800, which is slightly inferior to that of Example 1. Yes.
The filler for cationic chromatography produced by the method according to the present invention was able to produce a polymer film containing a double bond without requiring special conditions such as high temperature. Furthermore, the weakly acidic cation exchanger produced by this method showed a high separation of monovalent cations that could not be realized by other methods when packed in a column.

  According to the method of the present invention, a column packing material that realizes a chromatography column having a high theoretical plate number can be produced. In particular, a high performance weakly acidic cation exchanger can be produced under relatively mild conditions below the boiling point of the solvent.

The chromatogram obtained as a result of Example 1. The chromatogram obtained as a result of Comparative Example 1.

Claims (27)

  (a) A mixture containing a water-soluble polymer having an unsaturated group in the molecule or an aqueous solution thereof and (b) an organic solvent azeotropic with water is present on the surface of the carrier, and the solvent is distilled off to reduce the water content. A method for forming a polymer film, comprising the step of coating a carrier surface with a reduced polymer.   The method for forming a polymer film according to claim 1, further comprising a step of performing a crosslinking reaction of the polymer.   The method for forming a polymer film according to claim 2, wherein the crosslinking reaction is performed in a solvent in which the polymer is not dissolved.   The method for forming a polymer film according to claim 2 or 3, wherein, when the crosslinking reaction is performed, at least one functional group and a molecule having one unsaturated bond coexist, and the functional group is introduced into the polymer film.   The method for forming a polymer film according to claim 4, wherein the functional group is at least one functional group selected from the group consisting of a carboxylic acid group, a sulfonic acid group, and an amino group.   The method for forming a polymer film according to claim 5, wherein the molecule for introducing a functional group is ethylene-α, β-unsaturated dibasic acid.   The method for forming a polymer film according to claim 6, wherein the ethylene-α, β-unsaturated dibasic acid is maleic anhydride.   The method for forming a polymer film according to any one of claims 1 to 7, wherein the water-soluble polymer having an unsaturated group in the molecule is an unsaturated carboxylic acid-diene monomer copolymer.   The method for forming a polymer film according to any one of claims 1 to 8, wherein the unsaturated carboxylic acid-diene monomer copolymer is poly (butadiene-maleic acid).   The organic solvent azeotropic with water is at least one selected from the group consisting of aromatic hydrocarbons, alcohols, ketones, esters and ethers. Method for forming a molecular coating.   The method for forming a polymer film according to claim 10, wherein the organic solvent azeotropic with water is at least one selected from the group consisting of benzene, toluene, xylene, methyl ethyl ketone, ethyl acetate, and dioxane.   The method for forming a polymer film according to claim 11, wherein the organic solvent azeotropic with water is toluene.   (A) a mixture comprising a water-soluble polymer having an unsaturated group in the molecule or an aqueous solution thereof and (b) an organic solvent azeotropic with water, further comprising (c) an organic solvent miscible with water. Item 13. A method for forming a polymer film according to any one of Items 1 to 12.   14. The method for forming a polymer film according to claim 13, wherein the organic solvent miscible with water is at least one selected from alcohols, ketones, esters, ethers, and nitriles.   The method for forming a polymer film according to claim 14, wherein the organic solvent miscible with water is at least one selected from the group consisting of methanol, ethanol, acetone, ethyl acetate, dioxane, and acetonitrile.   The method for forming a polymer film according to claim 15, wherein the organic solvent miscible with water is acetone.   The method for forming a polymer film according to any one of claims 1 to 16, wherein the carrier is an inorganic porous carrier or a polymer gel.   The method for forming a polymer film according to claim 17, wherein the inorganic porous carrier is silica gel.   The method for forming a polymer film according to claim 17, wherein the polymer gel is a polyvinyl alcohol gel.   The method for forming a polymer film according to any one of claims 17 to 19, wherein the carrier is a spherical porous particle having a weight average particle diameter of 1 to 100 µm.   The polymer film manufactured by the method in any one of Claims 1-20.   21. A carrier-polymer film composite having a polymer film produced by the method according to claim 1 on its surface.   The carrier-polymer film composite according to claim 22, which is a column filler.   A polymer film having at least one functional group selected from the group consisting of a carboxylic acid group, a sulfonic acid group, and an amino group introduced on its surface, a weakly acidic cation exchanger, a strongly acidic cation exchanger, or The carrier-polymer film composite according to claim 22 or 23, which is an anion exchanger.   The weakly acidic cation exchanger according to claim 24, wherein the introduced functional group is a carboxylic acid group.   An ion chromatography column, wherein the ion exchanger according to claim 24 is used. A weakly acidic cation chromatography column, wherein the weakly acidic cation exchanger according to claim 25 is used.

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