JP5386805B2 - Method for producing porous crosslinked polymer, porous crosslinked polymer, porous crosslinked polymer particles and adsorbent - Google Patents

Description

  The present invention relates to a method for producing a porous crosslinked polymer, porous crosslinked polymer particles, and an adsorbent. Specifically, the present invention relates to a novel compound excellent in applicability to the reverse phase chromatography separation method, porous crosslinked polymer particles formed using the compound, and an adsorbent formed using the same.

Aromatic crosslinked polymer particles such as crosslinked polystyrene are industrially used as synthetic adsorbents for extraction and purification of useful substances from fermented products, foods, herbs, and the like. In addition, the aromatic crosslinked polymer particles having a small particle diameter are also used as a liquid chromatography filler, and are particularly applied to analysis and fractionation by a reverse phase liquid chromatography separation method.
Aromatic cross-linked polymer particles such as cross-linked polystyrene are excellent in chemical durability even under acidic and alkaline conditions, that high adsorption can be obtained by using porous particles, and adsorption selectivity with silica gel-based adsorbents. It has excellent characteristics as a synthetic adsorbent, such as being different.

As such crosslinked polymer particles, for example, those disclosed in Patent Documents 1 to 6 are disclosed. However, in accordance with the demand for improvement of separation ability in the reverse phase liquid chromatography separation method, hydrophobic substance adsorption ability (hydrophobic property) Further improvement of sex interaction is desired.
On the other hand, as the aromatic crosslinked polymer particles having an alkyl chain, non-porous polymer particles are disclosed for the purpose of separating and analyzing nucleic acids (Patent Documents 7 and 8). However, since these are non-porous in order to avoid the spread of the separation band due to substance diffusion, it cannot be said that the surface area is small and the interaction with the separation target is not sufficient, and low molecular weight compounds having a molecular weight of 2000 or less are separated. It could not be diverted to the reverse phase liquid chromatography separation method. On the other hand, in the conventional reversed-phase liquid chromatography separation method, inorganic porous particles such as silica gel that do not cause the separation band to spread due to the diffusion of the organic compound into the particles are used as the substrate. That is, unlike the above-mentioned fields for the purpose of separating and analyzing a nucleic acid that is a macromolecule having a molecular weight of tens of thousands or more in Patent Documents 7 and 8, reversed-phase liquid chromatography separation for low molecular weight compounds having a molecular weight of 2000 or less. In particular, use of porous aromatic cross-linked polymer particles having an alkyl chain, because the separation band spread due to material diffusion into the pores of the porous aromatic cross-linked polymer particles adversely affects the separation performance. That was not advantageous. Further, it has not been possible for those skilled in the art to predict the effect of making this porous.
Patent Document 9 discloses an alkyl chain-containing porous polymer and a liquid chromatography filler containing the same. However, this is obtained by random copolymerization of a monomer mixture containing an alkylstyrene derivative, and the distribution of the alkyl chain utilizing the interaction with the separation target becomes uniform inside the particle, and the separation target is In order to interact with the alkyl chain, it is necessary to diffuse to the inside of the particle, and there is a problem in terms of spreading of the separation band due to substance diffusion, and further improvement has been demanded.
Japanese Patent No. 3626774 JP 59-87089 A JP 54-163993 A JP 2002-30121 A JP-A-4-292605 Japanese Patent No. 3842288 US Pat. No. 5,585,236 International Publication No. 98/48913 JP 11-193310 A

  The present invention has been made in view of the above circumstances, and the object thereof is a porous crosslinked polymer having a high hydrophobic substance adsorption ability (hydrophobic interaction) and particularly excellent applicability to a reverse phase chromatography separation method. And a porous cross-linked polymer particle and an adsorbent formed using the same.

As a result of intensive studies to solve the above problems, the present inventor is excellent in hydrophobic substance adsorption ability (hydrophobic interaction) of a porous aromatic crosslinked polymer obtained by a specific production method. I found out. That is, the gist of the present invention is as follows.
[1] A method for producing porous crosslinked polymer particles having a structural unit represented by the following general formula (I) and having a most frequent pore radius of 10 to 300 mm , wherein the porous aromatic crosslinking method for producing a porous cross-linked polymer particles characterized by having a the polymer as engineering to introduce an alkyl group having 1 to 20 carbon atoms.

(In general formula (I), R represents an alkyl group having 1 to 20 carbon atoms.)
[2] Porous crosslinked polymer particles produced by the production method of [1].
[3 ] An adsorbent formed using the porous crosslinked polymer particles of [ 2 ].

  According to the present invention, a compound having high hydrophobic substance adsorption ability (hydrophobic interaction), and particularly excellent in applicability to the reverse phase chromatography separation method, porous crosslinked polymer particles formed using the compound, and adsorption An agent can be provided.

Hereinafter, the present invention will be described in detail with reference to examples and the like. However, the present invention is not limited to the following examples and the like, and can be arbitrarily modified and implemented without departing from the gist of the present invention.
[1] Porous cross-linked polymer The porous cross-linked polymer of the present invention (hereinafter sometimes simply referred to as “cross-linked polymer”) mainly satisfies the following (i) and (ii). It is.
(I) having a structural unit represented by the general formula (I) described later (ii) having a step of introducing an alkyl group having 1 to 20 carbon atoms into the porous aromatic crosslinked polymer; The structural unit will be described in detail.
[1-1] Structural unit represented by general formula (I)
The structural unit represented by the following general formula (I) in the present invention will be described.
In general formula (I), A represents a direct bond or a divalent organic group.

In general formula (I), R represents a linear or branched alkyl having usually 1 or more, preferably 4 or more, and usually 20 or less, more preferably 18 or less. When the number of carbon atoms is too large, it is difficult to produce crosslinked copolymer particles carrying an amount usable for reverse phase chromatography separation.
Specific examples of -R in the present invention include an octadecyl group and a t-butyl group.

[1-2] Production Method The porous crosslinked polymer particle of the present invention must have a process of introducing an alkyl group having 1 to 20 carbon atoms. As described above, in the method obtained by polymerizing a monomer mixture containing an alkylstyrene derivative, the distribution of the alkyl chain utilizing the interaction with the separation target is uniform within the particle, and the separation target is the alkyl chain. In order to interact with the particle, it is necessary to diffuse to the inside of the particle, which is problematic in terms of spreading of the separation band due to material diffusion. The present invention has technical significance in solving such problems.
Specifically, the porous crosslinked polymer particles of the present invention can be produced according to the method [2-4] described later.

[2] Porous crosslinked polymer particles
The porous crosslinked polymer particle of the present invention is formed using the above-mentioned compound of the present invention. Hereinafter, the porous crosslinked polymer particles of the present invention will be described.
[2-1] Weight average particle diameter
The porous crosslinked polymer particles of the present invention have a weight average particle size of usually 0.1 μm or more, preferably 1 μm or more, more preferably 2 μm or more, and usually 3000 μm or less, preferably 1000 μm or less, more preferably 800 μm or less. . If the weight average particle diameter is too small, the resistance of the liquid phase will be high when the column is used as a reverse phase packing material for liquid chromatography, and it will be difficult to send the mobile phase. As a result, the desired separation performance cannot be obtained. The weight average particle diameter is measured by a method selected from the following methods according to the particle size distribution range of the target particles.

<Weight average particle diameter measuring method 1 (water sieving method)>
Mainly used for particles having a particle size distribution range of 300 μm to 1000 μm.
According to the range of the particle size distribution of the target particles, sieves with sieve diameters of 1180 μm, 850 μm, 710 μm, 600 μm, 425 μm, and 300 μm are stacked so that the sieve diameter becomes smaller as it goes downward. The stacked sieve is placed on a bat, and about 100 mL of porous crosslinked polymer particles are placed in a 1180 μm sieve stacked on the top.

Gently pour water onto the resin from a rubber tube connected to tap water and screen the small particles downward. The porous cross-linked polymer particles remaining in the 1180 μm sieve are further screened for small particles by the following method. That is, water is filled up to a depth of about 1/2 of another bat, and a 1180 μm sieve is repeatedly shaken by giving up and down and rotational motion in the bat, and small particles are sieved.
The small particles in the vat are returned to the next 850 μm sieve, and the porous crosslinked polymer particles remaining on the 1180 μm sieve are collected in another vat. If the pores are clogged with porous cross-linked polymer particles, place the sieve in the vat reversely, tightly contact the rubber tube connected to tap water, and strongly flow water to clog the porous cross-linked polymer clogged with the screen. Take out the coalesced particles. The taken-out porous crosslinked polymer particles are transferred to a bat where the porous crosslinked polymer particles remaining on the 1180 μm sieve are collected, and the volume is measured with a graduated cylinder. Let this volume be a (mL). The porous crosslinked polymer particles passed through a 1180 μm sieve were subjected to the same operation for 850 μm, 710 μm, 600 μm, 425 μm, and 300 μm sieves, respectively, and volumes b (mL), c (mL), d (mL ), E (mL), and f (mL) are obtained, and the volume of the porous crosslinked polymer particles finally passed through a 300 μm sieve is measured with a graduated cylinder to be g (mL).

V = a + b + c + d + e + f + g, a / V × 100 = a ′ (%), b / V × 100 = b ′ (%), c / V × 100 = c ′ (%), d / V × 100 = d ′ ( %), E / V × 100 = e ′ (%), f / V × 100 = f ′ (%), g / V × 100 = g ′ (%).
From the above a ′ to g ′, the residual amount cumulative (%) of each sieve is taken on one axis, and the diameter (mm) of the sieve mesh is taken on the other axis, and this is plotted on the logarithmic probability paper. Take 3 points in the order of the remaining amount, draw a line that satisfies these 3 points as much as possible, obtain the diameter (mm) of the sieve mesh corresponding to 50% of the accumulated residue from this line, and calculate the weight average The particle size.
In addition, the calculation method of the said weight average particle diameter is described, for example in Mitsubishi Chemical Corporation ion exchange resin division "Diaion I basics edition" 14th edition (September 1, 1999) pp.139-141. This is a known calculation method.

<Weight average particle diameter measurement method 2 (robot shifter method)>
Used mainly for particles having a particle size distribution range of 20 μm to 300 μm.
About 3 g of the sample is weighed, about 0.06 g of white carbon is put in it, and disposable polyethylene gloves are used. This is put in the uppermost part of a JIS standard sieve set in a sonic vibration type automatic sieving particle size distribution measuring instrument (Seishin Enterprise Robot Shifter RPS-85). In addition, the standard sieve used uses the sieve prescribed | regulated to the particle size range of resin.

Hereinafter, a specific measurement example in the case of a porous crosslinked polymer particle sample having a particle size range of 63 μm to 212 μm will be described.
The operating conditions of the robot shifter are sieved under the conditions of LEVEL (strength) 2, TIME (time) 10 minutes, and INTERVAL (interval) 1 second. The weight of resin on each sieved sieve is automatically measured. The white carbon does not remain on the sieve having a particle size of 63 μm or more because the particle size is 63 μm or less.

The volume ratio at each particle size is calculated by the following formula.
V = a + b + c + d + e + f + g, a / V × 100 = a ′ (%), b / V × 100 = b ′ (%), c / V × 100 = c ′ (%), d / V × 100 = d ′ ( %), E / V × 100 = e ′ (%), f / V × 100 = f ′ (%), g / V × 100 = g ′ (%).

Here, a ′ (%) is a volume ratio of particle size of 212 μm or more, b ′ (%) is a volume ratio of 180 μm or more and less than 212 μm, c ′ (%) is a volume ratio of 150 μm or more and less than 180 μm, d ′ ( %) Is a volume ratio of 106 μm or more and less than 150 μm, e ′ (%) is a volume ratio of 75 μm or more and less than 106 μm, f ′ (%) is a volume ratio of 63 μm or more and less than 75 μm, and g ′ (%) is 63 μm. Indicates a volume ratio of less than.

From the above a ′ to g ′, the residual amount cumulative (%) of each sieve is taken on one axis, and the diameter (mm) of the sieve mesh is taken on the other axis, and this is plotted on the logarithmic probability paper. Take 3 points in the order of the remaining amount, draw a line that satisfies these 3 points as much as possible, obtain the diameter (mm) of the sieve mesh corresponding to 50% of the accumulated residue from this line, and calculate the weight average The particle size.
In addition, the calculation method of the said weight average particle diameter is the same as the said measuring method 1, For example, Mitsubishi Chemical Corporation ion exchange resin division "Diaion I basics" 14th edition (September 1, 1999) This is a known calculation method described on pages 139 to 141.

<Weight average particle size measurement method 3 (Coulter counter method)>
Mainly used for particles having a particle size distribution range of 1 μm to 200 μm.
A sample is used as a dispersion of a predetermined aqueous sodium chloride solution, and an aperture whose particle size range to be measured is 2 to 60% of the aperture diameter is used.
Using a Coulter counter (manufactured by Beckman Coulter), measurement is performed using a suspension in which a sample is dispersed in a 7% by weight sodium chloride aqueous solution so that the value of the densitometer is 5 to 10%. The number of measurements is 30,000, and the average diameter of volume statistics obtained by measurement is the weight average particle diameter. In addition, a uniformity coefficient is calculated | required by following Formula (I) from the 40% diameter and 90% diameter of the volume statistic value obtained by a measurement.

Uniformity coefficient = {40% diameter (μm)} / {90% diameter (μm)} (I)
The porous crosslinked polymer particles of the present invention having the above weight average particle diameter can be obtained by, for example, a known classification method. As a classification method, classification using a sieve, water sieve using a water stream, wind sieve using an air stream, sedimentation classification using a sedimentation speed difference, centrifugal classification using a centrifugal force, and the like can be used.

[2-2] Uniformity coefficient
The porous crosslinked polymer particles of the present invention preferably have a sharp particle size distribution, and the uniformity coefficient shown by the following calculation method is usually 1.7 or less, preferably 1.5 or less, more preferably 1.3 or less. is there. If the uniformity coefficient is too large, the number of theoretical plates of the column will not increase when porous crosslinked polymer particles are packed into the column for reverse phase chromatography separation, and sufficient separation will not be obtained.

<Uniformity coefficient calculation method>
Using the a ′ to g ′ calculated in the method of calculating the weight average particle diameter described in [2-1] above, the cumulative residual amount (%) of each sieve on one axis and the diameter of the sieve mesh on the other axis ( mm) and plot this on log-probability paper. Take 3 points in the order of the remaining amount, draw a line that satisfies these 3 points as much as possible, and obtain the diameter (mm) of the sieve mesh corresponding to 90% of the remaining amount from this line, and use this as the effective diameter. .

In the same manner as the effective diameter, the diameter (mm) of the sieve mesh corresponding to the remaining cumulative 40% is obtained, and the uniformity coefficient is obtained by the following equation (I).
Uniformity coefficient = {diameter of mesh (mm)} corresponding to 40% cumulative residue / {effective diameter (mm)} (I)
In addition, the calculation method of the said uniform grain coefficient is described in Mitsubishi Chemical Corporation ion exchange resin division "Diaion I basics edition" 14th edition (September 1, 1999) pp. 139-141, for example. This is a known calculation method.

The porous crosslinked polymer particles of the present invention having the above-mentioned uniformity coefficient can be obtained, for example, by a known classification method. As a classification method, classification using a sieve, water sieve using a water stream, wind sieve using an air stream, sedimentation classification using a sedimentation speed difference, centrifugal classification using a centrifugal force, and the like can be used. Also, Japanese Patent Application No. 6
The porous crosslinked polymer particles of the present invention having the above-mentioned uniformity coefficient can also be obtained by the uniform particle size production technique described in 3-0116916.

[2-3] Other physical properties
Since the porous crosslinked polymer particles of the present invention can enhance the interaction with the separation target by increasing the specific surface area, the porous crosslinked polymer particles need to be porous particles. The specific surface area is usually 10 m ² / g or more, preferably 40 m ² / g or more, more preferably 200 m ² / g or more. If the specific surface area is too small, a high adsorption amount cannot be obtained. On the other hand, when high separation performance is desired as in high performance liquid chromatography, non-porous particles can be used in order to avoid a decrease in the number of theoretical plates of the column due to the diffusion of separation objects in the pores. The particle surface area is measured by a BET (Brunauer Emmet Teller) method using nitrogen gas.

When it is made porous to increase the adsorption capacity, the radius of the pores is such that the object to be separated by reverse phase chromatography diffuses in the pores and can interact with the porous crosslinked polymer particle inner surface. A size is necessary.
Accordingly, a preferable most frequent pore radius is appropriately selected depending on the size of an object to be separated, but is usually 10 mm or more, preferably 20 mm or more, and usually 300 mm or less, preferably 200 mm or less. If the most frequent pore radius is too large, the specific surface area will be reduced, and the interaction between the separation target and the alkyl group will be reduced. If it is too small, it will be difficult for the compound to be separated to diffuse into the pores and the separation band will spread. As a result, the separation performance deteriorates.
The most frequent pore radius can be measured from the relationship between the nitrogen partial pressure and the nitrogen adsorption amount in the BET (Brunauer Emmet Teller) method using nitrogen gas. In addition, the pore volume in each pore diameter can also be measured by this method.

[2-4] Production Method The porous crosslinked polymer particles of the present invention can be produced, for example, by introducing a desired alkyl group on the basis of known porous aromatic crosslinked polymer particles. Examples of the porous aromatic crosslinked polymer particles include porous crosslinked polymer particles having a crosslinked structure skeleton obtained by copolymerization of a monovinyl aromatic monomer and a crosslinkable aromatic monomer. Examples of monovinyl aromatic monomers include alkyl-substituted styrenes such as styrene, methylstyrene, and ethylstyrene; polycyclic aromatic monovinyl monomers such as monovinylbiphenyl, benzylstyrene, monovinylvinylnaphthalene, and monovinylanthracene; and halogen-substituted styrenes such as bromostyrene. Kind. Among these, styrene, ethyl styrene, or a monomer mainly composed of styrene is preferable. Examples of the crosslinkable aromatic monomer include divinylbenzene, trivinylbenzene, divinyltoluene, divinylnaphthalene, divinylxylene, divinylbiphenyl, divinyldiphenylmethane, and the like. Of these, divinylbenzene is preferred. Industrially produced divinylbenzene usually contains a large amount of by-product ethyl vinylbenzene (ethyl styrene), but such divinylbenzene can also be used in the present invention.

Specific examples include porous styrene-divinylbenzene crosslinked polymer particles.
Commercially available porous aromatic crosslinked polymer particles can be used. As the porous aromatic crosslinked polymer particles used as the base for the porous crosslinked polymer particles of the present invention, for example, Diaion HP21 (trade name, manufactured by Mitsubishi Chemical Corporation), Diaion HP20 (trade name, Mitsubishi Chemical), Diaion HP20SS (trade name, manufactured by Mitsubishi Chemical), Diaion HP21SS (trade name, manufactured by Mitsubishi Chemical), MCI GEL CHP20P (trade name, manufactured by Mitsubishi Chemical), MCI GEL CHP20Y (product) Name, manufactured by Mitsubishi Chemical), MCI GEL CHP20A (trade name, manufactured by Mitsubishi Chemical), MCI GEL CHP55Y (trade name, manufactured by Mitsubishi Chemical), MCI GEL CHP55A (trade name, manufactured by Mitsubishi Chemical), MCI
GEL CHP5C (trade name, manufactured by Mitsubishi Chemical Co., Ltd.), MCI GEL CHP10M (trade name, manufactured by Mitsubishi Chemical Co., Ltd.), Sepa Beads SP20SS (trade name, manufactured by Mitsubishi Chemical Co., Ltd.), Sepabies SP70 (trade name, manufactured by Mitsubishi Chemical Co., Ltd.), Sepabies SP700 (trade name, manufactured by Mitsubishi Chemical Corp.), Sepabee SP825 (trade name, manufactured by Mitsubishi Chemical Corp.), Sepabee SP825L (trade name, manufactured by Mitsubishi Chemical Corp.), Sepabies SP850 (trade name, manufactured by Mitsubishi Chemical Corp.), Sepabies SP207 ( Product name, manufactured by Mitsubishi Chemical Co., Ltd., Sepabies SP207SS (trade name, manufactured by Mitsubishi Chemical Corporation), Amberlite XAD-2 (trade name, manufactured by Spellco), Amberlite XAD-4 (trade name, manufactured by Rohm and Haas) Amberlite XAD-16 (trade name, manufactured by Rohm and Haas), Amberlite XAD-18 Trade name, manufactured by Rohm and Haas), Amberlite XAD-1180 (trade name, manufactured by Rohm and Haas), Amberlite XAD-1600 (trade name, manufactured by Rohm and Haas), Amberlite XAD-1800 (trade name) , Rohm and Haas), Amberlite XAD-2000 (trade name, manufactured by Rohm and Haas), Amberlite XAD-2010 (trade name, manufactured by Rohm and Haas), Amber Chrome CG-161m (Product name, Rohm) Andhers), Amberchrome CG-161c (trade name, manufactured by Rohm and Haas), Amberchrome CG-300s (trade name, manufactured by Rohm and Haas), Amberchrome CG-300m (trade name, Rohm and Haas) Amber Chrome CG-1000s (trade name, low Andhers), Amberchrome XT-20 (trade name, manufactured by Rohm and Haas), Amberchrome XT-30 (trade name, manufactured by Rohm and Haas), Dowex L493 (trade name, manufactured by Dow Chemical) , Dowex Optipore V493 (trade name, manufactured by Dow Chemical Company), Dowex Optipore V502 (trade name, manufactured by Dow Chemical Company), Dowex Optipore V503 (trade name, manufactured by Dow Chemical Company), Dowex Optipore SD-2 ( Trade name, manufactured by Dow Chemical Co., Ltd., Muromac SAP-9516 (trade name, manufactured by Muromachi Chemical Co., Ltd.), Muromac SAP-9610 (trade name, manufactured by Muromachi Chemical Co., Ltd.), Muromac SAP-9630 (trade name, manufactured by Muromachi Chemical Co., Ltd.) , Muromac SAP-9520 (trade name, manufactured by Muromachi Chemical Co., Ltd.) Lebatit VPOC 1064 MDPH (trade name, manufactured by LANXESS), Lebatit VPOC 1163 (trade name, manufactured by LANXESS), Lebatit S
7768 (trade name, manufactured by LANXESS), Source 15 RPC (trade name, manufactured by GE Healthcare), and the like.
Next, a method for introducing an alkyl group into the porous aromatic crosslinked polymer particle will be described with an example.
Examples of the method for producing a porous crosslinked polymer having a structural unit represented by the general formula (I) include, for example, an octadecyl group, a t-butyl group, etc. on the phenyl group of a porous aromatic crosslinked polymer serving as a base. Aromatics in which alkyl groups such as octadecyl group and t-butyl group have been substituted beforehand into unreacted double bonds derived from the crosslinkable monomer of the porous aromatic cross-linked polymer as a base Examples thereof include a method of graft polymerization of a monomer.

As a method for substituting an alkyl group such as octadecyl group or t-butyl group for the phenyl group of the porous aromatic crosslinked polymer, for example, when substituting the octadecyl group, a solvent such as dichloroethane, Examples thereof include a method of reacting an alkyl halide such as octadecyl chloride in the presence of a Lewis acid catalyst such as iron. The atmospheric temperature during the reaction is usually 30 ° C. or higher, preferably 50 ° C. or higher, and is usually 120 ° C. or lower, preferably 100 ° C. or lower.

Further, the alkyl halide such as octadecyl chloride to be reacted is usually 5% by weight or more, preferably 10% by weight or more, and more preferably 20% by weight or more with respect to the porous aromatic cross-linked polymer as a base. If the amount of alkyl halide such as octadecyl chloride is too small, the amount substituted for the aromatic crosslinking monomer is small, and a sufficient effect cannot be obtained.
After completion of the reaction, the reaction mixture is filtered and washed with a solvent such as dilute hydrochloric acid, acetone or xylene to obtain a porous crosslinked polymer having an aromatic ring substituted with an octadecyl group.
As a method of graft polymerization of an aromatic monomer in which an alkyl group such as octadecyl group or t-butyl group has been substituted in advance to an unreacted double bond derived from a crosslinkable monomer of a porous aromatic crosslinked polymer as a base For example, when producing a porous aromatic crosslinked polymer having an octadecyl group, a radical polymer such as benzoyl peroxide is started by dissolving a solution in which an aromatic monomer substituted with an octadecyl group is dissolved in a solvent such as toluene. After being absorbed into the porous aromatic cross-linked polymer together with the agent, by heating to a temperature equal to or higher than the Unkai temperature of the radical polymerization initiator, unreacted derived from the cross-linkable monomer of the porous aromatic cross-linked polymer And a method of radical graft copolymerizing an aromatic monomer substituted with a double bond and an octadecyl group. As the atmospheric temperature during the reaction, a temperature at which decomposition occurs within a predetermined reaction time is appropriately selected according to the half-life decomposition temperature of the radical polymerization initiator to be used. When benzoyl peroxide having a 10-hour half-life temperature of 73.6 ° C is used, it is usually 60 ° C or higher, preferably 80 ° C or higher, and usually 120 ° C or lower, preferably 100 ° C or lower. The aromatic monomer substituted with the octadecyl group to be reacted is usually 5% by weight or more, preferably 10% by weight or more, more preferably 20% by weight or more, based on the porous aromatic crosslinked polymer as a base. It is. If the amount of the aromatic monomer is too small, the amount of substitution with the aromatic crosslinking monomer is small and a sufficient effect cannot be obtained. If the amount of aromatic monomer is large, it may be used as a solvent as it is.

  After completion of the reaction, the reaction mixture is separated by filtration and washed with a solvent such as acetone or toluene to obtain a porous crosslinked polymer having an aromatic ring substituted with an alkyl group.

[3] Adsorbent
The porous crosslinked polymer particles of the present invention are suitably used as an adsorbent. The adsorbent of the present invention is suitably used as a separating agent and a liquid chromatography packing, and particularly when used as a liquid chromatography packing, it is preferably used in a reverse phase chromatography separation method.

Hereinafter, the present invention will be specifically described by way of examples. However, the present invention is not limited to the following examples, and can be implemented with arbitrary modifications within the scope not departing from the gist of the present invention.
Hereinafter, the present invention will be specifically described by way of examples. However, the present invention is not limited to the following examples, and can be implemented with arbitrary modifications within the scope not departing from the gist of the present invention.

[1] Production / physical property evaluation of porous crosslinked polymer [1-1] Example 1
100 parts by weight of a small particle product (weight average particle diameter 54 μm, uniformity coefficient 1.29) of Diaion HP21 (manufactured by Mitsubishi Chemical Corporation), which is a commercially available porous aromatic monomer cross-linked polymer, is placed in a four-necked reaction flask. 1,500 parts by weight of 1,2-dichloroethane was added, and the mixture was allowed to stand at room temperature for 1 hour, and then 30 parts by weight of aluminum chloride and 100 parts by weight of 1-bromooctadecane were added and reacted at 80 ° C. for 5 hours. After completion of the reaction, the reaction mixture was separated by filtration and washed with 2 L of 2N hydrochloric acid, 2 L of demineralized water, and 2 L of acetone. The obtained crosslinked polymer of a porous aromatic monomer in which the octadecyl group was substituted with an aromatic ring was dried by heating to 50 ° C. with a vacuum dryer.
The weight average particle size and uniformity coefficient of the obtained crosslinked polymer of porous aromatic monomer were measured by a robot shifter method. The specific surface area was measured by the BET adsorption method. The pore volume was measured by a nitrogen multipoint adsorption method. The most frequent radius was measured by the BET method.
Table 1 shows the weight average particle diameter, uniformity coefficient, weight increase rate after alkylation, specific surface area, pore volume, and most frequent radius.

[1-2] Example 2
In the same manner as in Example 1 except that t-butyl bromide was used instead of 1-bromooctadecane as the alkylating agent, a crosslinked polymer of a porous aromatic monomer in which a t-butyl group was substituted with an aromatic ring was obtained.
Table 1 shows the weight average particle diameter, uniformity coefficient, weight increase rate after alkylation, specific surface area, pore volume, and most frequent radius.

[1-3] Example 3
A porous polymer of a porous aromatic monomer in which an isobutyl group is substituted with an aromatic ring is obtained in the same manner as in Example 1 except that 1-bromo-2-methylpropane is used in place of 1-bromooctadecane as an alkylating agent. It was.
Table 1 shows the weight average particle diameter, uniformity coefficient, weight increase rate after alkylation, specific surface area, pore volume, and most frequent radius.

[1-4] Example 4
A small particle product (weight average particle diameter 14.7 μm, uniformity coefficient 1.32) of Diaion HP21 (manufactured by Mitsubishi Chemical) as a porous aromatic monomer cross-linked polymer 1-bromooctadecane instead of 1-bromooctadecane as an alkylating agent A porous polymer of a porous aromatic monomer in which an octyl group was substituted with an aromatic ring was obtained in the same manner as in Example 1 except that iodooctane was used.
Table 1 shows the weight average particle diameter, uniformity coefficient, weight increase rate after alkylation, specific surface area, pore volume, and most frequent radius.

[1-5] Comparative Example 1
A commercially available small particle product of Diaion HP21 (weight average particle diameter 54 μm, uniformity coefficient 1.29) was used as the porous aromatic monomer crosslinked polymer particle, and the evaluation was made in the same manner.

[2] Hydrophobic evaluation of the obtained crosslinked copolymer by the reverse phase chromatography separation method In order to evaluate the hydrophobicity of the obtained alkyl group-substituted porous crosslinked polymer, a liquid feed pump, an auto sample injector, a column Using a high performance liquid chromatography (HPLC) apparatus equipped with an oven, an ultraviolet absorption detector and a data processing apparatus, the retention capacity ratio of phthalic diesters was measured under reverse phase chromatography conditions.
The alkyl group-substituted porous crosslinked polymer obtained in Examples 1 to 4 and the porous crosslinked copolymer of Comparative Example 1 were packed in a stainless steel column having an inner diameter of 4.6 mm and a length of 150 mm, and water / acetonitrile was used in a volume ratio. Reverse phase high speed of dimethyl phthalate and dipropyl phthalate and sodium nitrate aqueous solution, which is a sample for calculating the void volume, with a mixed solvent mixed at 40/60 as eluent at a flow rate of 0.5 ml / min Liquid chromatographic analysis was performed. Detection was performed with a 254 nm ultraviolet detector. The temperature of the column oven was 40 ° C.
The retention ratio (k ′) and retention volume ratio (α) for phthalic acid dimethyl ester and phthalic acid dipropyl ester were calculated by the following equations. k ′ = [(elution volume of each sample) − (elution volume of sodium nitrate)] / [(elution volume of sodium nitrate)]. α = (k ′ of dimethyl phthalate) / (k ′ of dimethyl phthalate).
Table 2 shows the retention ratio (k ′) and retention volume ratio (α) of dimethyl phthalate and dipropyl phthalate in the packed column in the obtained water / acetonitrile mixed eluent.

  The porous crosslinked polymer, porous crosslinked polymer particles and adsorbent produced by the method for producing a porous crosslinked polymer of the present invention have a high hydrophobic substance adsorption ability (hydrophobic interaction), and in particular, reverse phase chromatography. Excellent applicability to graphic separation methods. Therefore, industrial applicability is extremely high in each field such as food field, pharmaceutical field, other fermentation field, and bio field where the reverse phase chromatography separation method needs to be used.

Claims (3)

Have a structural unit represented by the following formula (I), a method for producing a porous cross-linked polymer particles most frequent pore radius is 10Å or more 300Å or less,
Method for producing a porous cross-linked polymer particles characterized by having a a porous aromatic cross-linked polymer particles as engineering to introduce an alkyl group having 1 to 20 carbon atoms.

(In general formula (I), R represents an alkyl group having 1 to 20 carbon atoms.) A porous crosslinked polymer particle produced by the production method according to claim 1. An adsorbent formed using the porous crosslinked polymer particles according to claim 2 .