JP2002194025A - Ethyl styrene-divinyl benzene copolymer and separating material for amino acids comprising the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a separating material excellent in the separating performance which can produce a high purity amino acid from a crude aqueous solution containing the plural amino acids. SOLUTION: The ethyl styrene.divinyl benzene copolymer is characterized in that a divinyl benzene unit of 60-97 wt.% and a styrene unit of 5 wt.% or less are contained with respect to a monomer unit of 100 wt.% which constitutes the copolymer. The separating material for amino acids is characterized by comprising the copolymer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ethylstyrene / divinylbenzene copolymer. More specifically, the present invention relates to an ethylstyrene-divinylbenzene copolymer for a separation material capable of separating amino acids such as leucine, isoleucine, and valine with high purity.

[0002]

2. Description of the Related Art Conventionally, as a method for producing each amino acid with high purity from a crude aqueous solution containing amino acids such as leucine, isoleucine, and valine, for example, a styrene-divinylbenzene copolymer was used as a separating material. A column chromatography method has been proposed in which the aqueous solution is injected into a column and then the developing solvent is passed through the column to fractionate and collect the eluted amino acids (Japanese Patent Publication No. Sho 61-2129).

[0003]

SUMMARY OF THE INVENTION The present inventors have developed a column chromatography using a separation material described in the above-mentioned publication from a crude aqueous solution containing valine and leucine and a crude aqueous solution containing valine and isoleucine. We tried to produce each amino acid with high purity by the method, but in order to obtain each amino acid with high purity, it was necessary to use a large amount of separation material for the amino acid, and the separation performance of the separation material Was found to be low. An object of the present invention is to provide a separation material which has excellent separation performance and can produce high-purity amino acids from a crude aqueous solution containing a plurality of amino acids.

[0004]

Means for Solving the Problems In order to solve the above problems, the present inventors have conducted intensive studies on a separating material composed of a divinylbenzene polymer. Ethylbenzene-divinylbenzene copolymer whose amount is less than or equal to the specified amount,
The present invention has been found to be excellent as a separating material for amino acids that can produce high-purity amino acids on a large scale without using a large amount of separating materials because of its excellent separation performance, and completed the present invention.

That is, the present invention contains 60 to 97% by weight of divinylbenzene units and 5% by weight or less of styrene units based on 100% by weight of monomer units constituting an ethylstyrene / divinylbenzene copolymer. An ethylstyrene-divinylbenzene copolymer characterized by containing, and a separating material for amino acids characterized by comprising the copolymer.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The ethylstyrene / divinylbenzene copolymer of the present invention has a divinylbenzene unit content of 60 to 97% by weight based on 100% by weight of monomer units constituting the ethylstyrene / divinylbenzene copolymer, The content of styrene units is 5% by weight or less. Among them, an ethylstyrene-divinylbenzene copolymer having a divinylbenzene unit content of 70 to 95% by weight and a styrene unit content of 3% by weight or less is preferable. An ethylstyrene-divinylbenzene copolymer having a divinylbenzene unit content of less than 60% by weight tends to decrease the purity of the amino acid obtained and to make it difficult to form a porous structure of the separating material. 97% by weight, not preferred
Is not preferred because the purity of the obtained amino acid tends to decrease.

Here, the divinylbenzene unit is a unit having, for example, o-divinylbenzene, m-divinylbenzene, p-divinylbenzene or the like as a monomer.
Units containing m-divinylbenzene and p-divinylbenzene as monomers are preferred. The ethylstyrene unit is, for example, o-ethylstyrene, m-ethylstyrene, p-
It is a unit containing ethylstyrene or the like as a monomer, and among them, a unit containing m-ethylstyrene or p-ethylstyrene as a monomer is preferable. Further, as a monomer unit of the ethylstyrene-divinylbenzene copolymer, for example,
Alkenyl group-containing hydrocarbons such as styrene and α-olefins; diene-based hydrocarbons such as butadiene and dicyclopentadiene; (meth) acrylic acids such as (meth) acrylate, (meth) acrylonitrile, and (meth) acrylamide; Monomer units such as vinyl esters such as vinyl acetate may be used as long as the purity of the obtained amino acid is not impaired.

The method for producing the ethylstyrene-divinylbenzene copolymer of the present invention includes, for example, monomers such as ethylbenzene and divinylbenzene, a suspension stabilizer, water,
In the presence of a polymerization catalyst or the like, as it is, or after removing oxygen, under a nitrogen atmosphere under normal pressure or pressure, 50
A suspension polymerization method in which stirring is performed at about 150 ° C. is exemplified.

The suspension polymerization method will be described in more detail. As the suspension stabilizer, for example, methyl cellulose,
Alkyl cellulose such as ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxyethylpropylcellulose and hydroxypropylmethylcellulose; higher fatty acid salts such as sodium oleate; higher alcohol sulfates such as sodium lauryl sulfate and ammonium lauryl sulfate; sodium dodecylbenzenesulfonate Anionic interfaces such as alkylbenzene sulfonates, naphthalene sulfonate derivatives such as sodium alkylnaphthalene sulfonates, dialkyl phosphates, polyoxyethylene alkyl ether sulfates, polyoxyethylene alkylphenol ether sulfates, and triethanolamine alkyl sulfates Activator: gelatin, polyvinyl alcohol, starch, polyacrylic Acid, polymethacrylic amide, bentonite, talc, aluminum hydroxide, alkaline earth metal sulfates and carbonates of the like.

In the suspension polymerization method, ethylstyrene-
An organic solvent is used to make the divinylbenzene copolymer porous. Examples of the organic solvent include aliphatic hydrocarbons such as pentane, hexane, heptane, octane and decane; aromatic hydrocarbons such as benzene, toluene, xylene and ethylbenzene; alicyclics such as cyclopentane, cyclohexane and cyclohexene. Hydrocarbons; halogenated hydrocarbons such as carbon tetrachloride, dichloroethane, trichloroethane, trichloropropane, chlorobenzene, dichlorobenzene, and bromobenzene; methyl benzoate, ethyl benzoate, methyl propionate;
And the like; esters such as butanol, amyl alcohol, hexanol and octanol. The amount of the organic solvent used may be, for example, 100
It is usually about 10 to 200 parts by weight with respect to parts by weight. Two or more organic solvents may be used as the organic solvent.

The amount of water used in the suspension polymerization is usually 100 to 100 parts by weight of the monomer used in the ethylstyrene / divinylbenzene copolymer.
It is about 1000 parts by weight. Further, water-insoluble inorganic compounds such as tricalcium phosphate, calcium carbonate, magnesium carbonate and bentonite may be used as a suspension stabilizing aid.

As the polymerization catalyst for the suspension polymerization method, for example,
Azo compounds such as azobisisobutyronitrile and azobisisovaleronitrile, and diisopropyl peroxydicarbonate, lauroyl peroxide, benzoyl peroxide, t-butyl peroxybenzoate,
Organic peroxides such as t-butyl peroxide and the like can be mentioned. The amount of the polymerization catalyst used was ethyl styrene.
It is usually about 0.01 to 3 parts by weight based on 100 parts by weight of the monomer used for the divinylbenzene copolymer.
As a method for producing an ethylstyrene-divinylbenzene copolymer, a suspension polymerization method described in Japanese Patent No. 2964662 is particularly preferable.

The thus obtained ethylstyrene / divinylbenzene copolymer can be used, for example, as a separation material such as column chromatography for amino acid production. Examples of the shape of the separation material of the present invention include crushed products such as spheres, cylinders (pellets), spheres and cylinders, and secondary aggregates thereof. The copolymer obtained by the suspension polymerization method is usually spherical. As the separating material of the present invention, a copolymer having two or more kinds of shapes may be mixed and used.

The average particle size of the separating material is usually 1 μm
３3 mm, preferably 10 μm-100
About 0 μm, particularly preferably 30 μm to 500 μm.
It is about μm. Also, the wider the particle size distribution of the separation material,
It is not preferable because the separation performance tends to decrease.
The average particle size and the particle size distribution can be determined by a laser method. The specific surface area of the pores in the separation material is usually from 100 m ² / (g-separation material) to 2000 m ² /
(G-separation material), preferably 300 m ² / (g
-Separation material) to about 1200 m ² / (g-separation material),
This specific surface area can be determined by a flow BET method. Here, m ² / (g-separation material) indicates a specific surface area (m ² ) per dry weight (g) of the separation material. The repetition pore radius of the separation material is usually 1 nm to 100 n.
m, and the radius can be determined by a mercury intrusion method.

The amino acids that can be produced by the separation material of the present invention include, for example, asparagine, aspartic acid, alanine, arginine, isoleucine, glycine, glutamine, glutamic acid, cystine, cysteine, serine,
Tyrosine, tryptophan, threonine, valine, histidine, hydroxyproline, hydroxylysine, phenylalanine, proline, methionine, lysine, leucine and other amino acids, among others, among others, asparagine, aspartic acid, alanine, arginine, isoleucine, glycine, glutamine, Aliphatic amino acids such as glutamic acid, cystine, cysteine, serine, threonine, valine, histidine, hydroxyproline, hydroxylysine, proline, methionine, lysine and leucine are preferred, with leucine, isoleucine and valine being particularly preferred.

In a crude aqueous solution containing an amino acid, the content of water is usually about 50 to 99% by weight, and the content of the produced amino acid is usually about 0.1% by weight.
It is about 1 to 50% by weight. In addition, the crude aqueous solution contains an amino acid other than the amino acid to be separated; a polypeptide obtained by polymerizing two or more amino acids; hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid,
Acids such as acetic acid; bases such as aqueous ammonia, sodium hydroxide, potassium hydroxide, and sodium carbonate; and inorganic salts such as salt may be contained.

As a method for producing a high-purity amino acid, for example, a crude aqueous solution containing an amino acid is mixed with a separating material,
After adsorbing only strong amino acids to the material,
A batch method in which the material is filtered and then amino acids are desorbed with a developing solvent; a column is filled with a separating material, a crude aqueous solution containing an amino acid is injected in a state filled with the developing solvent, and the solution is passed through the developing solvent. And amino acids are sequentially developed and eluted, and the column effluent is fractionated to obtain high-purity amino acids. US Pat.
No. 85589, a simulated moving bed method and the like, among which a column chromatography method and a simulated moving bed are preferable. Here, the weight ratio between the crude aqueous solution containing amino acids and the separating material is usually 1/100 to 100
/ 1, preferably 1/10 to 10/1.

Examples of a developing solvent used for producing a high-purity amino acid include pure water, diluted hydrochloric acid, diluted sulfuric acid, diluted nitric acid, and the like.
Examples include dilute phosphoric acid, dilute acetic acid, dilute aqueous ammonia, dilute aqueous sodium hydroxide, dilute aqueous sodium carbonate, and the like. Among the developing solvents, an aqueous solution adjusted to be weakly acidic to neutral is preferable.

As a flow rate of the developing solvent in the column chromatography method and the simulated moving bed, an SV value [｛(volume of the developing solvent passed through the separating material [L]) / (volume of the separating material [L]) ｝ / (Flow time [hr])] is usually 0.1 to 1
It is about 00, preferably 0.5 to 20. still,
The SV value is usually set based on the flow capacity per unit time and the capacity of the separating material so that the amino acid peak is completely separated. If the amino acid peak is not separated at a certain SV value, the amino acid can be extracted with high purity by lowering the SV value. That is, amino acids can be extracted with high purity by reducing the flow capacity per unit time or decreasing the amino acids relative to the capacity of the separation material. When the amino acid peak is sufficiently separated at a certain SV value, the SV value may be increased to separate a larger amount of amino acids. That is, the flow capacity per unit time may be increased, or more amino acids per separation material may be separated.

The operating temperature in the method for producing a high-purity amino acid is that it is necessary to prevent decay of the amino acid, maintain the dissolved concentration of the amino acid at a high level, improve the separation speed, and increase the thermal efficiency including the pre-processing and post-processing steps. From, usually
The temperature is about 2 to 90 ° C, preferably about 20 to 90 ° C.

The separating material of the present invention is a separating material having a separation coefficient α between valine and isoleucine of usually about 2.8 to 20, preferably about 3 to 10. Here, the separation coefficient α of the separation material means that the separation material is packed in a column and a 0.1% aqueous solution of phosphoric acid having a concentration of 10 g / L each of a substance having no adsorption action and valine and isoleucine is injected into the column. Then, valine and isoleucine are fractionated and recovered using a 0.1 mol% phosphoric acid aqueous solution as a developing solvent, and can be obtained from the respective holding capacities according to the following formula (1).

Α = (T ₂ −T ₀ ) / (T ₁ −T ₀ ) (1) [wherein T ₀ : holding capacity of a substance having no adsorption action (ml) T ₁ : holding capacity of valine (ml) ) T ₂ : represents the retention capacity (ml) of isoleucine. ]

Here, the reference substance refers to a substance having a small retention capacity, and usually includes amino acids such as glycine and alanine. Among them, glycine is preferred. In addition, the retention volume can be generally determined by multiplying the retention time (minute) of fractionation of each component by the flow rate (ml / min) of the developing solvent.

The separation material of the present invention can be produced by repeatedly using high-purity amino acids. The surface of the separation material is contaminated with impurities such as polypeptide contained in the crude aqueous solution,
When the separation coefficient α decreases, for example, methanol,
Organic solvents such as ethanol, propanol, acetone,
The separation coefficient α can be recovered by washing the separation material with an aqueous alkaline solution such as an aqueous sodium hydroxide solution or an aqueous potassium hydroxide solution, or an aqueous inorganic neutral salt solution such as an aqueous sodium chloride solution. In particular, when the polypeptide is a contaminant, an alkaline aqueous solution is preferable.

The high-purity amino acid thus obtained may be further purified by a method such as column chromatography or recrystallization repeatedly.

[0026]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Parts and percentages in the examples are on a weight basis unless otherwise specified.

(Production Example 1 of Ethylstyrene / Divinylbenzene Copolymer) A container equipped with a reflux condenser, a nitrogen inlet tube, a stirrer, and a thermometer was charged with 103 parts of pure water, and nitrogen gas was blown into the container. After the inside was replaced with nitrogen, 0.068 part of gelatin (Gelatin R manufactured by Nitta Gelatin Co., Ltd.) was dissolved in 2.2 parts of pure water and charged in the container. Next, a solution prepared by dissolving 0.45 part of hydroxypropyl methylcellulose (Metroze manufactured by Shin-Etsu Chemical Co., Ltd.) in 22 parts of pure water was charged into the container, and further, sodium alkylsulfonate (Kao Corporation) Emar) 0.0056
Was dissolved in 1.9 parts of pure water, and the obtained solution was charged into the container. 81% divinylbenzene, 1 ethylstyrene
56.2 parts of a solution composed of 8% and 1% of other monomer containing styrene, 36.7 parts of t-amyl alcohol, 0.56 part of lauroyl peroxide and 0.075 part of benzoyl peroxide are mixed and dissolved. And charged in the container.

Then, the temperature was raised over 1 hour under a nitrogen atmosphere, and after the temperature of the solution in the container reached 70 ° C., the mixture was stirred at about the same temperature for 6 hours. After completion of the polymerization reaction, t-amyl alcohol was distilled off from the vessel by distillation, and further filtered and washed with water to obtain 100 parts of an ethylstyrene-divinylbenzene copolymer. The copolymer has a most frequent pore radius of about 2
It was a porous sphere having a diameter of 0 nm, a specific surface area of about 840 m ² / g-copolymer and an average particle diameter of about 60 nm.

(Production Example 2 of ethylstyrene / divinylbenzene copolymer) Ethylstyrene / divinyl copolymer was prepared in the same manner as in Production Example 1 except that 36.7 parts of heptane was used instead of t-amyl alcohol of Example 1. A benzene copolymer was obtained. The physical properties of the obtained copolymer are shown in Table 1.

(Production Example 3 of Ethylstyrene-Divinylbenzene Copolymer) Instead of t-amyl alcohol of Example 1, 18.4 parts of heptane and t-amyl alcohol 1
An ethylstyrene-divinylbenzene copolymer was obtained in the same manner as in Production Example 1 except that 8.4 parts by weight of the mixed solvent was used. The physical properties of the obtained copolymer are shown in Table 1.

(Production Example 4 of Ethylstyrene-Divinylbenzene Copolymer) 81% of divinylbenzene of Example 1,
Instead of 56.2 parts of a solution composed of 18% of ethylstyrene and 1% of another monomer containing styrene, a solution 56 composed of 62% of divinylbenzene, 37% of ethylstyrene, and 1% of another monomer containing styrene was used. .2 parts and t-
Instead of amyl alcohol, 56.2 parts of heptane and t
-An ethylstyrene-divinylbenzene copolymer was obtained in the same manner as in Production Example 1 except that a mixed solvent of 56.2 parts of amyl alcohol was used. The physical properties of the obtained copolymer are shown in Table 1.

(Example 1) The copolymer obtained in Production Example 1 of ethylstyrene / divinylbenzene copolymer was directly packed as a separating material in a stainless steel column having an inner diameter of 4.6 mm and a length of 25 cm, and separated. Column (filling amount about 4.2
ml) was prepared. Glycine concentration 10 g / L, valine concentration 10 g / L and isoleucine concentration 10 g / L
0.0% of a crude aqueous solution containing 0.1% phosphoric acid
From the top of the column at an operating temperature of 20-25.
After injecting at 0.1 ° C., 18%
hr (SV = about 4.3 [{(volume of phosphoric acid aqueous solution [ml] passed through the separating material [ml])] / (volume of separating material [ml])} / (flow time [hr])] The solution was passed for 70 minutes. As a result, glycine was first eluted at 2.91 ml, followed by valine with a retention volume of 4.8 ml and isoleucine with 9.66.
eluted in ml. That is, the separation coefficient α between valine and isoleucine was about 3.6. At this time, the valine peak and the isoleucine peak were completely separated.

(Examples 2 to 5) Preparation of Ethylstyrene-Divinylbenzene Copolymer In the same manner as in Example 1, except that the copolymers obtained in Production Examples 2 to 4 were used, amino acids were separated. The separation coefficient α was determined. The results are shown in Table 1. In Example 5, the copolymer of Production Example 2 was used, and a mixed solution of valine and leucine was separated as a crude aqueous solution.

(Comparative Examples 1 to 3) Using a styrene-divinylbenzene copolymer containing no ethylstyrene unit as a separating material, amino acids were separated in the same manner as in Example 1 to obtain a separation coefficient α. The results are shown in Table 1. In addition, the following materials were used. Comparative Example 1: Diaion HP20 (manufactured by Mitsubishi Chemical Corporation, most frequent pore radius: about 26 nm, specific surface area: 600 m ² /
g-separating material) Comparative Example 2: Amberlite XAD2000 (manufactured by Rohm and Haas Co., Ltd., most frequent pore radius: about 12 nm, specific surface area: about 500 m ² / g-separating material) Comparative Example 3: Duolite S876 (Rohm and Haas) Manufactured by And Haas Co., Ltd., most frequent pore radius about 22 nm, specific surface area about 85
(0 m ² / g-separating material) The SV value of 4.3 is the minimum flow rate at which the peaks of valine and isoleucine can be completely separated.

[0035]

[Table 1]

[0036]

By using the copolymer of the present invention as a separation material for column chromatography, simulated moving bed, etc., amino acids such as leucine, isoleucine and valine can be used without using a large amount of separation material. It can be mass-produced with high purity. Further, the copolymer can be used as a separation material for analyzing amino acids.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08F 2/18 C08F 2/18 // (C08F 212/36 (C08F 212/36 212: 12) 212: 12 ) F-term (reference) 4D017 AA08 BA04 CA13 CB01 DA02 DA03 EA05 4G066 AB03A AB03B AB03C AC14B AC14C AE19B AE19C BA10 BA20 BA23 BA26 CA20 DA07 EA01 FA08 FA26 4H006 AA02 AD17 BS10 BU32 NB13 JA4 JA044 JA07 AB04Q AB16P CA04 FA21 JA15

Claims (4)

[Claims] (1) Divinylbenzene units are contained in an amount of 60 to 97% by weight and styrene units are contained in an amount of 5% by weight or less based on 100% by weight of monomer units constituting an ethylstyrene / divinylbenzene copolymer. Characterized ethylstyrene / divinylbenzene copolymer. 2. The ethylstyrene / divinylbenzene copolymer according to claim 1, wherein the ethylstyrene / divinylbenzene copolymer is obtained by suspension polymerization of ethylstyrene and divinylbenzene. 3. An amino acid separating material comprising the copolymer according to claim 1 or 2. 4. A method for producing a high-purity amino acid, comprising using the separation material according to claim 3.