JPH0314499B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a hydrophilic weakly basic anion exchange resin. In particular, the present invention relates to a weakly basic anion exchange resin that exhibits small volume changes during use. Examples of weakly basic anion exchange resins include crosslinked copolymers such as vinylbenzylamine, N-aminoalkylacrylamide, vinylpyridine, and (meth)acrylic acid esters of aminoalcohols, polyethyleneimine, aminoalkylcellulose,
Crosslinked products such as aminoalkyl dextran are well known. However, these weakly basic anion exchange resins generally have the disadvantage that they swell significantly in aqueous solutions and have a large volume change between the free base form and the loaded form. The present invention has a structural unit represented by the following general formula (1) and the following general formula (2), and is crosslinked with a crosslinking agent selected from polyacrylic esters and polymethacrylic esters of polyhydric alcohols. A crosslinked copolymer with a crosslinking agent content of 20 (by weight)
% to 80% (by weight) and has an ion exchange capacity of 0.1 to 3 meq/gr. (In the formula, R ₁ represents a hydrogen atom or a methyl group, and R ₂
and R ₃ represents a hydrogen atom or an alkyl group which may have a substituent. ) (In the formula, R ₁ represents a hydrogen atom or a methyl group.) The weakly basic anion exchange resin according to the present invention has appropriate hardness and has little volume change during use, so it can be used as a high-speed liquid. It is particularly suitable as a packing material for chromatography. To explain in detail the weakly basic anion exchange resin according to the present invention, this resin has a structural unit represented by the general formula (1) that provides anion exchange ability,
It has a structural unit represented by the general formula (2) that provides hydrophilicity, and further has a crosslinked structure using a crosslinking agent selected from polyacrylic esters and polymethacrylic esters of polyhydric alcohols. Polyacrylic esters or polymethacrylic esters of polyhydric alcohols usually include ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, propylene glycol dimethacrylate, dipropylene glycol dimethacrylate, Tripropylene glycol dimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol tetramethacrylate, 1,3-butylene glycol dimethacrylate and their corresponding acrylates are used alone or in mixtures. Preferably, diacrylate or dimethacrylate of ethylene glycol is used. These crosslinking agents should account for at least 20% (by weight) and at most 80% (by weight) of the resin. Particularly preferably 30 to 60 (by weight) of the resin
%. If the proportion of the crosslinking agent in the resin is too small, the resin will have a large swelling property, making it unsuitable for use as a filler for high performance liquid chromatography or other uses. On the other hand, if the ratio of the crosslinking agent becomes too large, the exchange capacity will decrease due to a decrease in the structural units represented by the general formula (1), or the hydrophilicity will decrease due to a decrease in the structural units represented by the general formula (2). bring. The structural unit represented by the general formula (1) is as follows:
Examples include those in which both or one of R ₂ and R ₃ is a hydrogen atom, an alkyl group, a hydroxy group-substituted alkyl group, an optionally substituted amino group-substituted alkyl group, and specifically, in the formula

[Formula] Structure: amino group, methylamino group, dimethylamino group, ethylamino group, diethylamino group, propylamino group, dipropylamino group, β-hydroxyethylamino group, bis(β-hydroxyethyl)amino group, β-aminoethylamino group, β-
It is a structural unit having a group such as an ethylaminoethylamino group or a β-(β-ethylaminoethyl)aminoethylamino group. Further, the structural unit of the general formula (1) is present in the resin in an amount such that the ion exchange capacity of the resin is 0.1 to 3 meq/g. If the ion exchange capacity is less than 0.1 meq/g, the resin is not practical as an ion exchange resin.
On the other hand, when the ion exchange capacity is greater than 3 meq/g, the volume change of the resin between the free base form and the loaded form becomes large, causing various practical problems. The preferred ion exchange capacity of the resin according to the present invention is
It is 0.3 to 2meq/g. The structural unit represented by the general formula (2) is expressed by the general formula (2) relative to the total number of moles of (the structural unit represented by the general formula (2) + the structural unit represented by the general formula (1)). Preferably, it is present in the resin in an amount such that the number of moles of the indicated structural unit accounts for 30 to 98%. When the amount of the structural unit represented by the general formula (2) is small, the hydrophilicity of the resin decreases. The resin according to the present invention includes the above-mentioned crosslinking agent part, the structural unit part represented by the above general formula (1), and the above-mentioned general formula (1).
Although it essentially consists of the structural unit moiety shown in (2), it may also contain a structural unit derived from methyl ester or ethyl ester of acrylic acid or methacrylic acid, if desired. The resin according to the present invention is produced by copolymerizing a crosslinking agent and a glycidyl ester of acrylic acid or methacrylic acid to form a crosslinked copolymer, and then reacting this with an amine to convert a portion of the glycidyl ester into 3-amino-2- It can be easily produced by converting the glycidyl ester into a hydroxypropyl ester and then reacting the epoxy ring of the glycidyl ester with water to open the ring. The polymerization reaction can be carried out by any known method, but
Usually, it is preferable to carry out suspension polymerization in an aqueous medium in the presence of a suitable dispersion stabilizer to obtain a granular copolymer. As the dispersion stabilizer, gelatin, sodium polyacrylate, carboxymethyl cellulose, polyvinyl alcohol, etc. are usually used. Further, it is preferable to dissolve salts in the aqueous medium to prevent the polymerization reaction raw material from dissolving in the aqueous medium. As the salt, sodium chloride, calcium chloride, sodium sulfate, sodium carbonate, etc. are used. The polymerization reaction is generally carried out using a suitable polymerization initiator. As a polymerization initiator, generally benzoyl peroxide, t-butyl hydroperoxide, azobisisobutyronitrile, dimethylazobis(methyl barate), azobis(α, α
-dimethylvaleronitrile), organic azobis compounds, etc. are used. These polymerization initiators usually account for 0.01 to 5 (by weight) of the reaction raw materials.
It is used in an amount such that %. The polymerization reaction is usually completed in 6 to 20 hours at 50 to 90°C under stirring. Furthermore, if a porous crosslinked copolymer is produced during this polymerization reaction, a porous, hydrophilic and weakly basic anion exchange resin can be obtained. Methods for producing porous crosslinked copolymers are well known, and usually include (1) the presence of a solvent in the reaction raw material that is homogeneously mixed therein but has little affinity for the crosslinked copolymer to be produced; (2) A method in which a linear polymer such as polystyrene is polymerized in the presence of a reaction raw material, and the linear polymer is extracted and removed from the resulting crosslinked copolymer; (3) A method in which the linear polymer is extracted and removed from the crosslinked copolymer produced. Linear polymers such as polystyrene are polymerized in the presence of a solvent that has an affinity for the resulting cross-linked copolymer, such as toluene, ethyl acetate, or dimethylformamide, and the resulting cross-linked copolymer is then polymerized. Any method of extracting and removing the polymer may be used. The reaction between the crosslinked copolymer and the amine can be carried out by dissolving the primary or secondary amine corresponding to formula (3) in a solvent such as water, methanol, dioxane, or toluene, and suspending the crosslinked copolymer in this. , the reaction may be carried out at 40 to 100°C for 3 to 10 hours. The degree of amination of the epoxy ring can be easily controlled by selecting reaction conditions. The ring-opening reaction of the epoxy ring can be carried out by suspending the aminated crosslinked copolymer in water containing sulfuric acid or phosphoric acid and holding the suspension at 30 to 100°C for 5 to 20 hours. The weakly basic anion exchange resin according to the present invention contains a glycerin monoester structure therein and is therefore highly hydrophilic. Furthermore, since the entire composition including the crosslinking agent is composed of aliphatic components and does not contain aromatic components, there is little physical adsorption of proteins and other various organic substances due to hydrophobic bonds.
Furthermore, the weakly basic anion exchange resin according to the present invention exhibits little volume change between the free base form and the loaded form, and is hard and causes little pressure loss when packed in a column. Therefore, the weakly basic anion exchange resin according to the present invention is useful as a packing material for chromatography, especially high performance liquid chromatography. EXAMPLES The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited to the following Examples unless it exceeds the gist thereof. In addition, the exchange capacity, swelling degree, and C/OH volume ratio of the ion exchange resin in this specification were measured as follows. Exchange capacity and swelling degree: Pour the OH type resin, which has been regenerated with an aqueous sodium hydroxide solution and thoroughly washed with demineralized water, into a 10 ml measuring cylinder, and tap the bottom to accurately collect 10 ml.
Weigh out. This resin was dehydrated using a centrifuge at 350G for 5 minutes, and then its weight (a ₁ g) was accurately weighed. Next, add this resin to 200ml of 0.2N hydrochloric acid aqueous solution.
Shake at room temperature for 24 hours. Titrate 20 ml of this aqueous hydrochloric acid solution with a 0.1N aqueous sodium hydroxide solution. Separately, accurately weigh out 10 ml of resin in the same manner as above, dehydrate it in the same manner as above, and then accurately weigh its weight (a ₂ g). Next, this resin was heated to 60℃,
After drying for 24 hours in a vacuum dryer at 10 mmHg,
Accurately weigh the weight (Cg) again. Swelling degree = 10/C (ml/g) Exchange capacity = (ho-h) x 0.1 x f x 200/20/a ₁
×C/a ₂ (meq/g) where h and ho are the amount of sodium hydroxide required for titration (ml) before and after adding the resin, respectively, and f is the factor of sodium hydroxide. It is. Cl/OH volume ratio After regenerating the resin with an aqueous sodium hydroxide solution and washing it with water, convert it to form C with 1N hydrochloric acid and thoroughly washing it with demineralized water. Pour this resin into a 10ml graduated cylinder and tap the bottom to accurately measure out 10ml. This resin is converted into OH form with a 1N aqueous sodium hydroxide solution, and then thoroughly washed with demineralized water. Ten
Measure the volume (dml) of the resin by tapping the bottom using a ml graduated cylinder. C/OH performance ratio = 10/d Example 1 Glycidyl methacrylate 210g, ethylene glycol dimethacrylate 90g, toluene 300g
and 3 g of 2,2'-azobis-2,4-dimethylvaleronitrile in 2100 ml of ion-exchanged water.
21g of polyvinyl alcohol and sodium chloride
It was added to a solution in which 168 g was dissolved, and suspension polymerization was carried out at 70° C. for 8 hours while stirring at high speed. After cooling the reaction product, the produced copolymer particles were collected and washed with water. Next, add this copolymer to 1125 ml of toluene and water.
The mixture was stirred at room temperature for 3 hours, and then filtered. Furthermore, this copolymer was poured into 1.5 methanol and stirred twice, and then dried at 80° C. for 8 hours. The particles subjected to the above operations were sieved to obtain 258 g of copolymer particles having a particle size of 50 to 100 μm. 50 g of the copolymer particles were placed in 250 ml of methanol, and 25 ml of a methanol solution containing 8% dimethylamine was added thereto with stirring, followed by reaction at 60° C. for 6 hours. The reaction product was taken and washed with ion-exchanged water. Next, put this in 250ml of 10% sulfuric acid aqueous solution,
The temperature was maintained at 90° C. for 5 hours while stirring. After cooling, the reaction product was taken and washed with water. Next, this was packed in a column, and 250 ml of a 2N aqueous sodium hydroxide solution was poured over 2 hours, followed by 1000 ml of demineralized water for washing. The exchange capacity of the anion exchange resin thus obtained was 0.23meq/
g, swelling degree is 3.37ml/g, C/OH volume ratio is
It was 1.01. Example 2 50 g of the copolymer particles obtained in Example 1 were placed in 250 ml of methanol, and 18 g of diethylamine was added thereto with stirring, followed by reaction at 60° C. for 6 hours. Thereafter, an anion exchange resin was obtained in exactly the same manner as in Example 1. The exchange capacity of the anion exchange resin thus obtained was 1.79 meq/g, the degree of swelling was 3.31 ml/g, and the C/
The OH volume ratio was 1.05. Example 3 25 g of the copolymer particles obtained in Example 1 were placed in 250 ml of methanol, and 25 ml of diethanolamine was added thereto with stirring, followed by reaction at 60° C. for 6 hours. Thereafter, an anion exchange resin was obtained in exactly the same manner as in Example 1. The anion exchange resin thus obtained had an exchange capacity of 1.68 meq/g, a swelling degree of 3.30 ml/g, and a C/OH
The volume ratio was 1.04.

Claims (1)

[Claims] 1. It has a structural unit represented by the following general formula (1) and the following general formula (2), and is crosslinked with a crosslinking agent selected from polyacrylic esters and polymethacrylic esters of polyhydric alcohols. is a crosslinked copolymer made of a polyester resin, the content of a crosslinking agent is 20% (by weight) or more and 80% (by weight) or less, and the ion exchange capacity is 0.1 to 0.1%.
Hydrophilic, weakly basic anion exchange resin with 3meq/gr. (In the formula, R ₁ represents a hydrogen atom or a methyl group, and R ₂
and R ₃ represents a hydrogen atom or an alkyl group which may have a substituent. ) (In the formula, R ₁ represents a hydrogen atom or a methyl group.)