JPH02122828A - Manufacture of adsorbent - Google Patents

Abstract

PURPOSE:To provide a good adsorbent by mixing and sticking together the spherical particles having a specific diameter and the ultrafine particles consisting of carbonaceous materials by mechanochemical method to coat the surfaces of the former uniformly with the latter, fixing them firmly and heat treating and baking. CONSTITUTION:The spherical particles consisting of phenol resin, naphthalene resin, furan resin, etc., and varying in size from 5mu to 120mu in diameter and the ultrafine particles consisting of carbonaceous materials (e.g., carbon black, colloidal graphite and graphite powder) and varying in size from 15nm to 100nm in diameter are mixed together by mechanochemical method, whereby the surfaces of the former are coated uniformly and firmly with the latter to form a porous spherical body, which, after its temperature is raised at a rate of 10-40 deg.C per hour for heat treatment at a temperature of 100-400 deg.C, is baked at a temperature of 800-3000 deg.C to obtain a carbonaceous and graphitized porous spherical adsorbent.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing an adsorbent, and more specifically, an adsorbent used in high performance liquid chromatography (HPLC), gel permeation chromatography (GPC), etc. The present invention relates to a method for producing a surface-porous spherical carbon or graphite adsorbent useful as a column packing material, etc.

[Prior Art and Problems to be Solved by the Invention] Conventionally, 0DS-silica-based packing materials have been mainly used as column packing materials because they allow good separation of samples; It has insufficient properties, especially alkali resistance, and it also has insufficient heat resistance because the side chains are separated and it loses its function as a filler under conditions exceeding about 120°C. I got angry.

In addition, highly porous crosslinked spherical polymer fillers are often used as column fillers for HPLC, GPC, etc., but as they swell with solvents, their volume changes, and the rate of volume change varies depending on the type of solvent. Furthermore, in terms of heat resistance, the use limit of currently commercially available products is 140 to 150°C (for high-temperature GPC), which is still not sufficient.

Therefore, carbon-based adsorbents such as activated carbon, which have been conventionally used for gas adsorption, solvent recovery, etc., have been considered as adsorbents to solve the above-mentioned problems. However, most commercially available activated carbon is in crushed or pellet form, and even if it is spherical, the majority have micropores with a pore size of less than 20 pores, so generally the pore size is between 20 and 1000 pores. HPL where transitional bore spherical adsorbent is preferably used
Activated carbon is generally unsuitable as a column packing material for C, GPC, etc. On the other hand, among conventional carbon-based adsorbents, HPLC
Even if it is possible to use it as a column packing material for SGPC, etc., it is difficult to arbitrarily and accurately control the pore size and particle size, and it is insufficient in terms of sample separation ability, etc. Met.

In view of the current situation, the present invention provides that the pore size and particle size can be adjusted arbitrarily.
It is precisely controlled, provides good sample separation, and has sufficient strength as a column packing material, excellent chemical resistance, and heat resistance, and does not cause volume changes due to solvent.
It is an object of the present invention to provide a method for producing an adsorbent useful as a column packing material for HPLCSGPC, etc.

[Means for Solving the Problems] The above object of the present invention is to provide a spherical material made of at least one of phenol resin, naphthalene resin, furan resin, xylene resin, divinylbenzene polymer, styrene-divinylbenzene copolymer, and mencarbon. A surface porous sphere obtained by mixing particles and fine particles made of carbonaceous material using a mechanochemical method to uniformly adhere and fix the fine particles on the surface of the spherical particles is heat-treated under certain conditions and then fired. achieved by.

That is, the present invention provides phenolic resin, naphthalene resin,
Furan resin, xylene resin, divinylbenzene polymer,
Spherical particles made of at least one of styrene-divinylbenzene copolymer and mesocarbon with a particle size of 5 to 120μ and fine particles made of a carbonaceous material with a particle size of 15 to 1100n are mixed by a mechanochemical method to obtain the spherical particles. Surface porous spheres obtained by uniformly adhering and fixing the fine particles to the surface are heated at a heating rate of 10 to 40 in an oxidizing atmosphere.
The temperature is raised at a rate of 100-400°C and then heated at a rate of 50-600°C/hr in an inert atmosphere or under vacuum.
The method of producing an adsorbent is characterized in that the temperature is raised for 1 hour and the final treatment temperature is 800 to 3000°C.

The spherical particles used as a starting material in the production method of the present invention are made of at least one of phenol resin, naphthalene resin, furan resin, xylene resin, divinylbenzene polymer, styrene resin, vinylbenzene copolymer, and mesocarbon, and include the following: It is carbonized and/or graphitized with good yield by calcination as detailed in .
Particles having a diameter of 5 to 120 microns are effectively used.

Further, in the production method of the present invention, the fine particles used as a starting material together with the above spherical particles include carbon black,
It is made of at least one type of carbonaceous material such as colloidal graphite, graphite powder, coke powder, and powder obtained by firing and carbonizing the compound that is a component of the above spherical particles, and the particle size is 15 to 100. rv is effectively used.

Note that the mixing ratio of each is preferably 1 to 4 parts by weight of fine particles to 100 parts by weight of spherical particles. By using the above-mentioned starting material, the fine particles can be well attached and immobilized on the surface of the spherical particles during mixing by the mechanochemical method described in detail below, and the desired adsorbent can be obtained well.

In the production method of the present invention, first, the above-mentioned spherical particles and fine particles are mixed by a mechanochemical method, and the fine particles are uniformly adhered and immobilized on the surface of the spherical particles to obtain a surface-porous sphere.

The mechanochemical method used in the production method of the present invention is generally also called a powder/powder mixing method. That is, by dry mixing different types of powders with different particle sizes (for example, spherical particles and fine particles in the present invention) under pressure, the fine particles are first attached to the surface of the spherical particles, and when further mixing is performed, the particles are attached to the spherical particles. Due to a mechanochemical reaction caused by mechanical impact, pressure, frictional force, etc. applied to the microparticles, the surface portion of the spherical particles in contact with the microparticles is softened, melted, etc., and the microparticles are immobilized on the surface of the spherical particles. In the present invention, this mixing can be carried out at room temperature or in air, and the mixing time is preferably 10 to 100 minutes. In addition, other conditions such as pressurization conditions are not particularly limited in the present invention, and are appropriately selected depending on the starting materials used, the processing amount, etc., so that each particle is not crushed during mixing and fine particles are formed on the surface of the spherical particles. It is sufficient that the adsorbent can be uniformly adhered and immobilized, resulting in a good adsorbent.

In addition, as the device used for mixing by the mechanochemical method mentioned above, a general mixing device such as a V-type mixer can be used as long as the process of adhering fine particles to the surface of spherical particles is possible, but it is possible to use a general mixing device such as a V-type mixer. The process involves mechanical shock, pressure,
A device that can continuously apply frictional force is required, and automatic mortar, centrifugal mixer, etc. are preferable. In the present invention, both the adhesion and immobilization steps can be performed successively using the same mixing device, or can be performed using separate devices.

Next, the surface porous spheres obtained as described above were heated at a heating rate of 10 to 40°C/h in an oxidizing atmosphere such as air or oxygen.
r to 100-400°C, preferably 0.1-
Heat treatment is performed by holding for 1 hour.

Furthermore, in the manufacturing method of the present invention, the surface-porous spheres heat-treated in this way are heated at a heating rate of 50 to 60% under an inert atmosphere such as nitrogen gas or argon gas or under vacuum.
Raise temperature at 0℃/hr, final treatment temperature 800-3000℃
Carbonization and/or graphitization treatment is performed by firing with
A carbon or graphitic superficially porous spherical adsorbent is obtained. In addition, during the above-mentioned firing, it is desirable to raise the temperature at a rate of 50 to 300°C/hr until the processing temperature reaches 1200°C, and it is preferable to hold the temperature at 1200°C or lower for 0.1 to 1 hour.

As described above, the carbon or graphite surface porous spherical adsorbent obtained by the production method of the present invention can be easily and precisely produced by selecting the particle diameters of the spherical particles and fine particles used. ~100μ, pore size 50
It is possible to arbitrarily obtain adsorbents in the range of ~350 people, and the specific surface area of the resulting adsorbents is between 2 and 10 m/g (
(based on the BET method). Moreover, the yield in the production method of the present invention is 10 to 70%.

[Examples] Hereinafter, the present invention will be described in more detail based on Examples.

Example 1 10.0 g of a commercially available spherical phenol resin sized to 18 to 22 μm by wet classification and 0.30 g of carbon black with an average particle size of 30 n days were used as starting materials.

After uniformly mixing these, a mixing treatment was carried out for 10 minutes in an automatic mortar to uniformly coat the surface of the spherical phenolic resin particles with carbon black particles, which were then fixed by a mechanochemical reaction to obtain surface-porous spheres. .

The surface particles and porous spheres were heated to 280° C. at a heating rate of 30° C./hr in air and held for 1 hour for heat treatment.

Next, the heat-treated surface porous spheres were placed in a nitrogen atmosphere for 2 hours.
The temperature was raised to 1000°C at a heating rate of 00°C/hr, held for 1 hour to carbonize, and then heated to 600°C in a graphitization furnace.
The temperature was finally raised to 2000°C at a heating rate of °C/hr to graphitize the mixture to obtain a graphitic surface porous spherical adsorbent.

The particle size of the obtained adsorbent was about 10±2μ, and the pore size was
Approximately 170±50 people, specific surface area by BET method is 5JT
It/g, and the yield was 44%.

This graphite surface porous spherical adsorbent was
It was wet-packed into a mj HPLC column and attached to an HPLC apparatus. After stabilizing the column by using an 80/20 wt% mixture of methanol/water as the eluent, a mixture of phthalate esters (1: dimethyl phthalate, 2: diallyl phthalate, 3: phthalate) was added under the following conditions. di-n-butyl). The resulting HPLC chart is shown in FIG.

(Measurement conditions) Flow rate 1.0aIi! /mln detector
UV (254 ns) Temperature: 26°C Pressure: 55 KW/ai As is clear from FIG. 1, the graphitic superficially porous spherical adsorbent obtained in Example 1 can It is possible to separate each of the above phthalate esters well.

Example 2 A graphite surface-porous spherical adsorbent was obtained in the same manner as in Example 1, except that the carbon black used had an average particle diameter of 47 rv and the amount used was 0.36 g.

The particle size of the obtained adsorbent was approximately 10±2μ, and the pore size was 2
00±50 people, specific surface area by BET method is 3.3T
The yield was 45%.

Using this graphite surface porous spherical adsorbent, a mixture of phthalate esters was separated in the same manner as in Example 1 under the following conditions. The resulting HPLC chart is shown in FIG.

(Measurement conditions) Flow rate 1.0d/+gln detector U
V (254 nm) Temperature: 25° C. Pressure: 95 Kg/ci As is clear from FIG. It is possible to separate each of the above phthalate esters well.

Example 3 First, polyvinyl alcohol 2 with an average molecular weight of 2000
0 g and 400 g of water are stirred in a flask to completely dissolve. Here, 50g of divinylbenzene and 50g of styrene.
mixed solution loOg, 1.0 g of benzene peroxide as a polymerization catalyst, and nonionic (nonionic surfactant; polycarboxylic acid type polymeric surfactant) as an emulsifier.
1. Add og and suspend, stirring for 75~
The polymerization reaction was initiated by heating to 85° C. and continued for 1 hour. During this time, the temperature of the reaction solution was raised to 95 to 98°C due to heat generated by the polymerization reaction. Thereafter, the obtained reaction solution was cooled to 50° C. or below while stirring, and further cooled to room temperature to obtain a dispersion. A spherical product was filtered from the resulting dispersion, washed twice with water and three times with methanol, and then dried at around 100°C while being careful not to catch fire from volatile components to obtain a spherical divinylbenzene polymer. I got it.

The procedure of Example 1 was repeated except that the obtained spherical divinylbenzene polymer was sized to 15 to 25μ by wet classification, and 10.0g of this and 0.30g of carbon black with an average particle size of 47ni were used as starting materials. A graphite surface-porous spherical adsorbent was obtained in the same manner.

The particle size of the obtained adsorbent is 8 to 15μ, and the pore size is 175.
±30 people, specific surface area by BET method is 3. OTIt
/g, and the yield was 14%.

When a mixture of phthalate esters was separated in the same manner as in Example 1 using this graphitic surface porous spherical adsorbent, results similar to those shown in FIG. 1 were obtained, and each of the phthalate esters were able to be separated well.

Example 4 Mesophase amount (optically anisotropic region) under polarized light microscopy field observation was 100%, softening point was 311°C, quinoline soluble content (Ql) was 17% by weight, and toluene insoluble content (TI) was 80% by weight. After finely pulverizing the coal-based bulk mesophase, it was classified to obtain pitch powder with a particle size of 25 to 50 μm.

80 g of the obtained pitch powder was mixed with 14 g of diisobutyl phthalate.
4 and the entire amount was put into a 204 autoclave.

After charging, the inside of the autoclave system was evacuated and purged with nitrogen gas. Then, to prevent the pitch powder from settling, immediately rotate the stirrer at 50 rpm, and while stirring,
The temperature was started to increase at 120°C/hr. Thereafter, as soon as the temperature inside the system reached 330° C., the system was allowed to cool to obtain a dispersion liquid. Note that stirring was continued until the temperature dropped to 150°C.

At this time, the maximum autogenous pressure was 6 kg/ci.

Next, the obtained dispersion was taken out from the autoclave and filtered by suction, and the filtered spherical product was washed with acetone and dried to prepare spherical mesocarbon microbeads.

The obtained spherical mesocarbon microbeads were sized to a size of 18 to 25μ by wet classification.

On the other hand, the furan resin was carbonized by heating to 1000° C. in a nitrogen atmosphere at a heating rate of 50° C./hr, then dry-pulverized, and further wet-pulverized using a ball mill. Next, the obtained powder was sized by wet classification to obtain carbonaceous fine particles with an average particle diameter of 100 rv.

064 g of the above carbonaceous fine particles and 15 g of mesocarbon microbeads were used as starting materials.

After uniformly mixing these, a mixing treatment is performed for 40 minutes in an automatic mortar to uniformly coat the surface of mesocarbon microbeads with carbonaceous particles, which are then immobilized by a mechanochemical reaction to obtain surface porous spheres. Ta.

This surface-porous sphere was heated to 300° C. at a heating rate of 30° C./hr in air and held for 1 hour for heat treatment.

Next, the heat-treated surface porous spheres were placed in a nitrogen atmosphere for 1
The temperature was raised to 1000°C at a heating rate of 00"c/hr for carbonization, and then the temperature was finally raised to 2300°C at a heating rate of 350°C/hr in a graphitization furnace for graphitization. A graphite surface-porous spherical adsorbent was obtained.

The particle size of the obtained adsorbent was approximately 15±3μ, and the pore size was 1
000±500 people, specific surface area by BET method is 2r
rt/g, and the yield was 70%.

This graphite surface porous spherical adsorbent is 411φX250
It was wet packed into an avJ HPLC column and attached to an HPLC apparatus. After stabilizing the column by using an 80/20 wt% mixture of methanol/water as the eluent, a mixture of dinitrobenzenes (11: o-dinitrobenzene, 12: m-dinitrobenzene, 13: p-dinitrobenzene) was added under the following conditions.
- dinitrobenzene) was separated. The resulting H
A PLC chart is shown in FIG.

(Measurement conditions) Flow rate 1. OId/sin detector U
V (254rv) Temperature: 25°C Pressure: 40 Kg/cM As is clear from Fig. 3, the graphitic superficially porous spherical adsorbent obtained in Example 4 can be , it is possible to separate each of the above dinitrobenzenes well.

[Effects of the Invention] As explained above, the carbonaceous or graphite superficially porous spherical adsorbent obtained by the production method of the present invention has particle size and pore size that can be adjusted arbitrarily and accurately depending on the purpose. Furthermore, since the surface area of the spherical adsorbent is porous, it can be used as a column packing material for HPLC, GPC, etc. to effectively separate samples.

In addition, since the adsorbent obtained by the present invention is carbonaceous or graphite obtained by calcination, it has sufficient strength as a column filler, has excellent chemical resistance and heat resistance, and does not cause volume change due to solvent. .

Therefore, the adsorbent obtained by the present invention can be used for HPLC, GP
Suitable for use as a column packing material for C, etc., for example, for the separation of various esters, various nitrogen-containing compounds containing tro groups, etc.), and the separation of substituents at the ortho, meta, and para positions. It is possible.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 respectively show mixtures of phthalate esters (
1 to 3), and FIG. 3 is an HPLC chart of a mixture of dinitrobenzenes (11-13) according to an example (Example 4) of the present invention. 1:2:3=ll:12:13: dimethyl phthalate, diallyl phthalate, di-n-butyl phthalate, 0-dinitrobenzene, m-dinitrobenzene, p-dinitrobenzene. Patent Applicant Nippon Carbon Co., Ltd. Agent Patent Attorney Tatsuo Ito Agent Patent Attorney Tetsuya Ito↑ Injection Elution time (min) o11 Figure

Claims (1)

[Claims] 1. Spherical particles with a particle size of 5 to 120 μ and a particle size of 15 to 100 nm made of at least one of phenol resin, naphthalene resin, furan resin, xylene resin, divinylbenzene polymer, styrene-divinylbenzene copolymer, and mesocarbon. A surface porous sphere obtained by mixing fine particles made of a carbonaceous material by a mechanochemical method and uniformly adhering and immobilizing the fine particles on the surface of the spherical particle is heated under an oxidizing atmosphere at a heating rate of 10 to 10. Raise the temperature at a rate of 40°C/hr and maintain it at 100-400°C, then raise the temperature at a rate of 50-600°C/hr in an inert atmosphere or vacuum, and bake at a final processing temperature of 800-3000°C. A method for producing an adsorbent characterized by: