JP3309926B2 - Method for producing porous beads - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to the food industry, pharmaceutical industry, electronics industry, wastewater treatment, artificial organs, medical treatment, etc.
Removal and recovery of proteins, colloids, bacteria, etc., adsorption and removal of harmful gases, decolorization, recovery and removal of harmful substances in water, collection of heavy metals, porous materials used as carriers for immobilization of enzymes and bacteria The present invention relates to a method for producing beads.

[0002]

2. Description of the Related Art JP-A-50-12176 and JP-A-50-12176 disclose methods for producing porous fine particles having an average particle size of several μm.
own of Polymer Science:
Part A-1, Vol. 6, 2689 (1968) proposes an oil-in-water emulsion polymerization method. That is, a homogeneous mixed solution of an oil-based polymerizable monomer and benzene is stirred in water containing a dispersant at a high speed for a long time to form an oil-in-water emulsion, which is polymerized by ionizing radiation or heat to form a porous film. This is a method for making fine particles.

[0003]

However, in this method,
There is a restriction that the solvent of the polymerizable monomer must be less than a certain solubility in water, and that a stable emulsion cannot be obtained unless oil droplets in the water have a certain size or less. Therefore, it is very difficult to produce porous particles having a size of several hundred microns to several millimeters by this method. Also, in this method, the particle size of the particles,
It is also very difficult to freely adjust the pore size of the porous part.

[0004] Further, the necessity of wastewater treatment,
The solvent of the monomer used in this method is benzene, carbon tetrachloride, chloroform or the like, which has a drawback that it is a harmful substance which may cause a health hazard specified in Article 57 of the Industrial Safety and Health Law. In addition, benzene is an occupational carcinogen specified by the International Agency for Research on Cancer (IARC). Therefore, when the porous particles are mass-produced by the conventional method, there is a possibility of causing environmental and human contamination.

[0005]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have completed the present invention. That is, the present invention relates to a monomer and / or oligomer (A) polymerizable by irradiation with energy rays.
And dissolves or dissolves in the monomer and / or oligomer (A) or dissolves in a homogeneous solution of the monomer and / or oligomer (A) and a solvent, and dissolves in the monomer and / or oligomer (A) A uniform polymerizable solution mixed with a phase separation agent (B) that is incompatible with the polymer generated by irradiating the energy ray and is inactive with respect to the energy ray is discharged in the form of droplets. An object of the present invention is to provide a method for producing a porous body, which comprises irradiating this with an energy ray and then removing a polymerizable solution that has not reacted with the phase separation agent (B).

The monomer and / or oligomer used in the present invention may be any substance, whether organic or inorganic, which can be polymerized by irradiation with energy rays to become a polymer, such as radical polymerizable, anionic polymerizable, and cationic polymerizable polymer. It may be arbitrary. For example, vinyl group, vinylidene group, acrylic group, methacryl group, acrylate,
Monomers containing methacrylic acid esters and / or
Alternatively, an oligomer may be used, but an oligomer having a high polymerization rate by irradiation with energy rays is preferable.

Specific examples of the monomer used in the present invention include ethyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, n-butyl (meth) acrylate, hexyl (meth) acrylate, -Ethylhexyl (meth)
Acrylate, phenyl (meth) acrylate, phenyl cellosolve (meth) acrylate, n-vinylpyrrolidone, isobonyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, lauryl (meth) acrylate ,

Monofunctional monomers such as 2-methoxyethyl (meth) acrylate, 2-acryloyloxyethyl hydrogen phthalate, dimethylaminoethyl (meth) acrylate, trifluoroethyl (meth) acrylate and trimethylsiloxyethyl methacrylate; diethylene glycol di (meth) ) Acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, polyethylene glycol di (meth) acrylate,

2,2'-bis (4- (meth) acryloyloxypolyethyleneoxyphenyl) propane,
Bifunctional monomers such as 2′-bis (4- (meth) acryloyloxypolypropyleneoxyphenyl) propane,
Trifunctional monomers such as trimethylolpropane tri (meth) acrylate and trimethylolethane tri (meth) acrylate, tetrafunctional monomers such as pentaerythritol tetra (meth) acrylate, and hexafunctional monomers such as dipentaerythritol hexaacrylate Is mentioned. Of course, it is also possible to use a mixture of these monomers.

[0010] The oligomer used in the present invention includes:
For example, it is polymerizable by energy ray irradiation and has a weight average molecular weight of 500 to 50,000, and specifically, for example, an acrylate or methacrylate of an epoxy resin, such as bisphenol A-diepoxy-acrylic acid adduct, Examples include acrylate or methacrylate of polyether resin, acrylate or methacrylate of polybutadiene resin, and polyurethane resin having an acryl or methacryl group at a molecular terminal. These oligomers can be used as a mixture, or can be used as a mixture with a monomer.

In the porous beads according to the present invention, the polymer produced therefrom can be any of non-crosslinked type and crosslinked type, and the crosslink density can be arbitrarily controlled by selecting the monomer and / or oligomer. Further, by using a monomer and / or an oligomer having a functional group, a hydroxyl group, a carboxylic acid group, silicon, a halogen,
Amino groups and the like can be easily introduced into the polymer.

The porous beads of the present invention are preferably of a crosslinked type in terms of pressure resistance, heat resistance, solvent resistance, chemical resistance and the like, but in particular, the residual amount of unreacted monomers and oligomers is reduced. When it is necessary to reduce the number of residual double bonds in the polymer, it is necessary to wash the resulting crosslinked porous beads with a solvent compatible with unreacted monomers and oligomers, such as ethanol. Thus, it is also possible to remove unreacted components.

[0013] Alternatively, non-crosslinked beads can be formed using a monofunctional monomer and / or oligomer. Whether the beads are cross-linked or non-cross-linked can be determined by the presence or absence of a solvent capable of dissolving the beads. In the case of a cross-linked type, it may swell in a gel state but does not dissolve.

The phase separating agent (B) used in the present invention includes:
It is compatible with or dissolved in the monomer and / or oligomer (A) used in the present invention, or is dissolved in a homogeneous solution of the monomer and / or oligomer (A) and a solvent, and the monomer and / or oligomer (A) is used. Any material may be used as long as it is incompatible with the polymer produced by irradiating the energy ray with the polymer and is substantially inert to the energy ray.

Therefore, the phase separating agent (B) used in the present invention can be changed depending on the type of monomer and / or oligomer. For example, when a polyurethane resin having an acryl group at a molecular terminal is used as a polymerizable oligomer. Include alkyl esters such as methyl caprate, dialkyl ketones such as diisobutyl ketone, liquid polyethylene glycol, monoesters of polyethylene glycol, polyethylene glycol monoether, mono-, di- and triesters of glycerin,

Alkyl esters having a hydroxyl group, alkylamines, polyethylene glycolamine, cellulose acetate, ethyl cellulose, nitrocellulose, chitosan, polystyrene, polyvinyl chloride, polycarbonate, polysulfone, polyethersulfone, polyurethane, polyacrylonitrile, polyacryl Acid esters,
Polyacrylic acid, polymethyl methacrylate, polyacrylamide, polyethylene glycol, polyvinylpyrrolidone, polyvinyl alcohol, and the like can be suitably used.

The phase separating agent (B) may be a single composition or a mixture. In the case of a mixture, the properties of the components alone are not particularly limited. For example, the individual components may be incompatible with the monomer and / or oligomer and the polymer may not swell or dissolve, or may be compatible with the polymer generated from the monomer and / or oligomer. It may be.

The swelling herein is a concept defined for a crosslinked polymer, and refers to a phenomenon that occurs when the crosslinked polymer is immersed in a solvent that dissolves a non-crosslinked polymer having the same chemical structure. In such swelling, the polymer can generally contain a solvent in an amount of 50% or more by weight of the polymer. The phase-separating agent (B) may be prepared by the following method: the method of producing beads; the type of monomer and / or oligomer; the required viscosity of a polymerizable solution; the solubility of a polymer or other additives; It can be appropriately selected depending on the shape of the pores and the like.

When ultraviolet light is used as the energy ray, the phase separation agent (B) preferably has a low ultraviolet absorption. Regarding the ratio of the phase separating agent (B) to the monomer and / or the oligomer, the ratio of the monomer and / or
Alternatively, the range is preferably 1 to 5 parts by weight, and more preferably 2 to 3 parts by weight per 1 part by weight of the oligomer. If it is less than 1, the porosity of the film will be low, and if it is more than 5, the strength of the beads will be insufficient.

The selection of monomers and / or oligomers is based on the viscosity of the polymerizable solution, the combination of the type of the phase separator (B) and the solvent, and the strength and flexibility of the resulting beads.
It is determined by heat resistance, swelling resistance, pore diameter, degree of hydrophilicity, presence or absence of a functional group, and the like. For example, in order to obtain porous beads having excellent heat resistance, a system containing only polyfunctional monomers and / or oligomers or a system containing many polyfunctional monomers and / or oligomers is selected. Conversely, when heat resistance is not required, a system containing only monofunctional monomers and / or oligomers or a system containing a large amount of monofunctional monomers and / or oligomers may be selected.

When the content of the phase separating agent (B) is increased in order to increase the porosity of the beads, it is desirable to select a high molecular weight oligomer in order to maintain the strength of the beads.
When increasing the pore size, it is preferable to reduce the viscosity of the polymerizable solution by selecting a monomer and / or oligomer (A) or a phase separator (B) having a relatively low molecular weight. In addition, depending on the purpose of use, to obtain hydrophilic or water-repellent beads, it is possible to select a monomer or oligomer containing a hydroxyl group, a carboxyl group, a sulfonic acid group, an ammonium salt, or fluorine or a silyl group,
Further, these monomers and oligomers can be mixed.

If necessary, a polymerization initiator, a sensitizer and the like can be added to the polymerizable solution, that is, a mixture of the monomer and / or the oligomer and the phase separation agent (B). The viscosity of the polymerizable solution does not need to be particularly limited,
It can be adjusted arbitrarily. The viscosity of the polymerizable solution affects the shape of the pores, and generally speaking, when the polymerizable solution has a low viscosity, the shape of the pores may be given as gaps between finely divided polymers adhered to each other. On the other hand, when the viscosity is high, on the contrary, it is often provided as a gap of a polymer deposited in a network. Also, the higher the viscosity, the smaller the pore size tends to be.

The viscosity of the polymerizable solution can be adjusted by the type of the monomer and / or the oligomer, the type of the phase separating agent (B), the additives, and the mixing ratio thereof. The pore size also affects the mixing ratio between the monomer and / or oligomer and the phase-separating agent (B). When the ratio of the monomer and / or oligomer becomes higher than a certain level, the pore size tends to decrease. Of course, these behaviors depend on the monomer and / or oligomer (A) and the phase separation agent (B).
Can be determined depending on the combination of these materials and the intended performance of the porous beads.

In the method for producing a porous bead of the present invention, the polymerizable solution is extruded from a nozzle under the condition that the polymerizable solution is formed into a droplet or a droplet during free fall, and the droplet is irradiated with an energy ray. It is a manufacturing method characterized by the above-mentioned. It is also possible that the extrusion from the nozzle is a spray. As the polymerizable solution, for example, the polymerizable solution may be naturally dropped from a glass pipette, or may be sent using a liquid sending pump. In the latter case, it is possible to easily prepare porous beads by adjusting the distance between the nozzle and the energy beam irradiation zone so that the polymerizable solution enters the energy beam irradiation zone after forming a droplet. Can be.

The particle size of the porous beads can be controlled by adjusting the size of the cross-sectional area of the discharge port of the nozzle and the discharge linear velocity of the polymerizable solution. The pore diameter of the porous beads is affected not only by the composition of the polymerizable solution but also by the linear velocity at which the polymerizable solution is discharged and the shear rate between the polymerizable solution and the nozzle when the polymerizable solution is extruded from the nozzle. The shear rate as referred to in the present invention means the linear velocity at which the polymerizable solution is discharged (cm / sec).
c) divided by the slit width of the nozzle discharge port.

For example, the shear rate is 10 to 350,000 s
Under the condition of ec ^-1 , the pore diameters of the obtained beads are almost uniformly distributed, but the shear rate is 360000 to 10000.
Under the condition of 00 sec ⁻¹ , the pore size of the outer surface of the obtained beads is smaller than that of the inside of the beads. The discharge linear velocity can be controlled by adjusting the discharge amount of the polymerizable solution or the cross-sectional area of the nozzle discharge port.

The energy beam used in the porous beads and the production method of the present invention includes an electron beam, γ-ray, X-ray,
Examples include ultraviolet light and visible light. Among them, ultraviolet rays are most preferable because of simplicity of equipment and handling. The intensity of the irradiated ultraviolet light is preferably from 10 to 5000 mw / cm ² , and the irradiation time is from about 0.01 to 10 seconds.
In the process of continuously producing beads by irradiating energy rays to the droplet-shaped polymerizable solution extruded from the nozzle,
The irradiation time is the residence time of the droplet in the irradiation range.

It is also preferable to increase the polymerization rate by irradiating ultraviolet rays in an inert gas atmosphere. When ultraviolet rays are used as energy rays, it is also preferable to include an ultraviolet polymerization initiator in the polymerizable solution for the purpose of increasing the polymerization rate. The UV polymerization initiator used in the present invention does not need to be particularly restricted, but is preferably a substance which can be dissolved in a polymerizable solution, for example, p-tert-
Butyltrichloroacetophenone, 2,2'-diethoxyacetophenone, 2-hydroxy-2-methyl-1-
Acetophenones such as phenylpropan-1-one;

Benzophenone, 4,4'-bisdimethylaminobenzophenone, 2-chlorothioxanthone,
-Methylthioxanthone, 2-ethylthioxanthone,
Ketones such as 2-isopropylthioxanthone; benzoin ethers such as benzoin, benzoin methyl ether, benzoin isopropyl ether and benzoin isobutyl ether; benzyl ketals such as benzyl dimethyl ketal and hydroxycyclohexyl phenyl ketone;

An electron beam is also a preferable energy beam that can be used in the present invention. The use of an electron beam is not affected by the presence or absence of absorption of extraneous radiation such as the phase separation agent (B) and other additives, so that the range of choice is widened and the production speed of beads is also increased. Further, since a polymerization initiator is not required, it is easy to apply to an application in which the residual is a problem.

The atmosphere in the energy ray irradiation zone preferably has an oxygen concentration of 5% or less, but may be any fluid such as air, water, degassed water, petroleum ether or the like as long as it is not compatible with the polymerizable solution. . The atmosphere for extruding the polymerizable solution in the form of droplets, or the atmosphere for the energy beam irradiation zone,
A gas is preferred because it is simple and does not require a subsequent drying operation, but any fluid may be used as long as it is not compatible with the polymerizable solution, for example, air, water, degassed water, petroleum ether and the like.

When the monomer and / or oligomer (A) undergoes a reaction inhibition by oxygen during polymerization by energy ray irradiation, the oxygen concentration of the atmospheric gas is preferably 10% or less, and preferably 5% or less. More preferably, it is most preferably 1% or less.
The distance between the nozzle and the energy beam irradiation position is 10 to 100
0 mm is preferred, and 50 to 300 mm is more preferred. If the distance is too large, the time required for the droplet to pass through the energy beam irradiation zone, that is, the energy beam irradiation time is shortened, and the polymerization may be insufficient. If the distance is too small, clogging and contamination of the nozzle due to polymerization on the nozzle surface due to leakage of energy rays are likely to occur.

The length of the energy beam irradiation zone is not particularly limited, and may be appropriately determined depending on the size and intensity of the light source, the linear velocity of the polymerizable solution, and the like. After solidification of the polymerizable droplet, irradiation can be performed in a longer section or in a separate step for the purpose of increasing the crosslink density or reducing unreacted monomer. The solidified beads may be dropped on a table or a container, or may be dropped and accumulated in ethanol or water.

The obtained beads may be washed, if necessary, with a phase separator (B), unreacted monomers and / or oligomers (A) filled in the pores by washing, an ultraviolet polymerization initiator, and other additives. And so on. The detergent may be any as long as it can dissolve the phase separation agent (B), the polymerization initiator, unreacted components and other additives. Further, it is preferable to use a solvent such as ethanol in order to avoid effects on the environment and the human body. When water or a water-soluble substance is used as the phase separation agent, it can be used without washing.
The obtained beads may be subjected to a heat treatment as necessary to adjust the pore size and increase the dimensional stability or heat resistance.

The porous beads produced according to the present invention are:
It has a large number of communication holes of 0.01 μm or more and 10 μm or less. A porous bead having a communication hole is one in which individual minute voids in the bead are connected to each other, and a liquid can freely move in the bead and pass through the bead. The pore size may be uniform within the beads,
There may be a pore size distribution. For example, the pore diameter may change continuously or discontinuously from the outside of the bead toward the spherical core, or may be evenly distributed.

The pore size of the porous beads can be measured by a mercury intrusion method. The particle size of the porous beads produced according to the present invention is 0.01 to 7 mm. Porous beads having a small particle size can be obtained by spraying a polymerizable solution from a nozzle and curing with an energy beam. The shape of the porous beads produced according to the present invention is not limited to a sphere, and may be particles of any shape such as a spheroid, a raindrop, a disk, a dish, a hemisphere, and the like.

[0037]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the scope of the present invention.

Example 1 (Preparation of Polymerizable Solution) A urethane acrylate oligomer having a molecular weight of 800 and having an average of three acrylic groups per molecule (trade name: Unidick V-4263, Dainippon Ink and Chemicals, Inc.) 80 parts), 20 parts of 2,2-bis [4- (acryloxydiethoxy) phenyl] propane, 2 parts of Irgacure-184 (ultraviolet polymerization initiator, manufactured by Ciba Geigy), and 160 parts of methyl decanoate. A polymerizable solution 1 having a viscosity of 30 cps at 23 ° C. was obtained.

(Preparation of Porous Beads) Diameter 0.53 mm
20 ml of polymerizable solution 1
/ Min (discharge linear velocity 151 cm / sec, shear rate 284
When the polymerizable solution was extruded into the air at 9 sec ^-1 ), the polymerizable solution had a cylindrical shape immediately below the nozzle, and formed a droplet at a position of about 10 cm or less below the nozzle. A range of 30 to 60 cm below the nozzle is irradiated with a 36 KW metal halide lamp at a wavelength of 36.
Irradiation with ultraviolet light of 0 nm was performed using a focusing mirror.

The cured beads were dropped into a container 100 cm below the nozzle. The obtained wet beads were milky white. The beads were washed with ethanol and water, and sufficiently dried under reduced pressure to obtain white beads having no gloss on the surface. (Characteristics of Beads) The beads have a diameter of 0.9 mm. According to an electron microscope, a mesh-like structure having a pore diameter of about 1 μm is observed on the outer surface, and polymer particles adhered to each other are cut inside. And pores provided as the gaps were observed. When 0.3 g of the beads were measured with a mercury porosimeter (manufactured by Carlo Elba), the peak of the pore size distribution was 0.8 μm, and the volume porosity was 51.5%.

When 1.0 g of the beads were placed in 100 ml of a 0.3% aqueous solution of albumin and stirred at room temperature for 2 hours, it was found from the decrease in albumin concentration that 23.8 mg of albumin had been fixed to the beads. . Albumin immobilized on the beads was not desorbed even after washing with a large amount of water. On the other hand, dimethylformamide, dimethylacetamide, which is a solvent for the acrylic polymer,
When immersed in dimethyl sulfoxide or the like, it swelled and became transparent, but did not dissolve. The contact angle of the beads with water was measured with a Kyowa CA-4D contact angle meter. Table 1 shows the obtained values and other characteristics.

Example 2 (Preparation of Polymerizable Solution) The same polymerizable solution as in Example 1 was used. (Preparation of beads) Using a needle-shaped nozzle having a diameter of 0.16 mm, polymerizable solution 1 was discharged at 80 ml / min (discharge linear velocity 6
631 cm / sec, shear rate 414438 sec ^-1 )
And extrude it into the air with a 6KW metal halide lamp at a wavelength of 360 nm
Was irradiated using a condenser mirror.

The cured beads were dropped into a container 100 cm below the nozzle. The obtained wet beads were milky white. The beads were washed with ethanol and water, and sufficiently dried under reduced pressure to obtain white beads having a glossy surface. (Characteristics of beads) These beads have a diameter of 0.3 mm, and according to an electron microscope, a dense layer in which no holes are observed on the outer surface, polymer particles adhered to each other inside, and fine particles provided as gaps. Holes were observed. 0.3 g of these beads is used as a mercury porosimeter (Carlo Elba)
As a result, the peak of the pore size distribution was 0.2 μm,
The volume porosity was 50.1%.

When 1.0 g of the beads was placed in 100 ml of a 0.3% aqueous albumin solution and stirred at room temperature for 2 hours, it was found from the decrease in albumin concentration that 10.2 mg of albumin had been fixed to the beads. . Albumin immobilized on the beads was not desorbed even after washing with a large amount of water. On the other hand, when the beads were immersed in a solvent of an acrylic polymer such as dimethylformamide, dimethylacetamide, dimethylsulfoxide and the like, they swelled and became transparent but did not dissolve. The contact angle of the beads with water was measured with a Kyowa CA-4D contact angle meter. The obtained values are shown in Table 1 with other characteristics.

Example 3 (Preparation of Polymerizable Solution) Epoxy acrylate oligomer having a weight average molecular weight of 1000 and having two acrylic groups on average in one molecule (trade name: NK Oligo EA-6310, Shin-Nakamura Chemical Co., Ltd.) 95 parts, trimethylsiloxyethyl methacrylate (trade name: SI-HEMA, manufactured by Osaka Organic Chemical Industry), 5 parts, Irgacure-184 (ultraviolet polymerization initiator, manufactured by Ciba Geigy), 2 parts, polyethylene glycol monolaurate 200 The polymerizable solution 1 having a viscosity of 80 cps at 23 ° C. was obtained.

(Preparation of Beads) Beads were prepared in the same manner as in Example 1 except that a nozzle having a discharge port diameter of 3 mm was used. The polymerizable solution left the nozzle as droplets.
The obtained wet beads were milky white. The beads were washed with ethanol and water, and sufficiently dried under reduced pressure to obtain white beads having no gloss on the surface.

(Characteristics of Beads) The beads have a diameter of 5.
According to an electron microscope, a network structure having a pore diameter of about 0.7 μm was observed on the outer surface, and polymer particles adhered to each other and pores provided as gaps were observed inside. When 0.3 g of the beads were measured with a mercury porosimeter (manufactured by Carlo Elba), the peak of the pore size distribution was 0.7 μm, and the volume porosity was 54.1%.

When 1.0 g of the beads was placed in 100 ml of a 0.3% aqueous albumin solution and stirred at room temperature for 2 hours, it was found from the decrease in albumin concentration that 1.7 mg of albumin had been fixed to the beads. . Albumin immobilized on the beads was not desorbed even after washing with a large amount of water. On the other hand, when the beads were immersed in a solvent of an acrylic polymer such as dimethylformamide, dimethylacetamide, dimethylsulfoxide and the like, they swelled and became transparent but did not dissolve. The contact angle of the beads with water was measured with a Kyowa CA-4D contact angle meter. Table 1 shows the obtained values and other characteristics.

Example 4 (Preparation of Polymerizable Solution) A urethane acrylate oligomer having a molecular weight of 800 and having an average of three acrylic groups per molecule (trade name: Unidick V-4263, Dainippon Ink and Chemicals, Inc.) 50 parts, polyethylene glycol 40
0 diacrylate (trade name: NK Ester A-400, manufactured by Shin-Nakamura Chemical Co., Ltd.) 25 parts, 2-acryloyloxyethyl hydrogen phthalate (trade name: M-5400, manufactured by Toa Gosei Chemical Co., Ltd.), 25 parts, Irgacure-184
2 parts of (ultraviolet polymerization initiator, manufactured by Ciba Geigy) and 160 parts of methyl decanoate were mixed to obtain a polymerizable solution 1.

(Preparation of Beads) Beads were prepared in the same manner as in Example 1. The obtained wet beads were milky white. The beads were washed with ethanol and water, and sufficiently dried under reduced pressure to obtain white beads having no gloss on the surface.

(Characteristics of Beads) The beads have a diameter of 0.
According to an electron microscope, a network having a pore diameter of about 1 μm was observed on the outer surface, polymer particles adhered to each other, and pores provided as gaps were observed inside.
When 0.3 g of these beads were measured with a mercury porosimeter (manufactured by Carlo Elba), the peak of the pore size distribution was 0.4%.
7 μm, and the volume porosity was 52.1%. When 1.0 g of the beads was placed in 100 ml of a 0.3% aqueous albumin solution and stirred at room temperature for 2 hours, 6.1 mg of albumin was found to be fixed to the beads based on the decrease in albumin concentration. Albumin immobilized on the beads was not desorbed even after washing with a large amount of water.

On the other hand, when the beads were immersed in a solvent of an acrylic polymer such as dimethylformamide, dimethylacetamide, dimethylsulfoxide, etc., they swelled and became transparent but did not dissolve. The contact angle of the beads with water was measured with a Kyowa CA-4D contact angle meter. Table 1 shows the obtained values and other characteristics.

Example 5 (Preparation of Polymerizable Solution) The same polymerizable solution as in Example 1 was used. (Preparation of beads) 0.16, 0.20,
Using a 0.26, 0.36 and 0.53 mm needle-shaped nozzle, the polymerizable solution 1 is extruded into the air at 32 ml / min, and a range of 30 to 60 cm below the nozzle is irradiated with ultraviolet light having a wavelength of 360 nm by a 6 KW metal halide lamp. Was irradiated using a condenser mirror. The cured beads were dropped into a container 100 cm below the nozzle. The obtained wet beads were milky white. The beads were washed with ethanol and water, and sufficiently dried under reduced pressure to obtain white beads.

(Characteristics of Beads) When the diameters of these beads were plotted with respect to the diameter of the discharge port of the nozzle, the linear relationship shown in FIG. 1 was obtained.

[0055]

[0056]

According to the present invention, a porous bead having a wide range of particle size and pore size design range, a large specific surface area, and excellent strength, creep resistance, heat resistance and chemical resistance is obtained. It is possible to provide a method for producing porous beads produced at a production rate by a simple particle size control method.

[Brief description of the drawings]

FIG. 1 is a diagram showing the relationship between the diameter (mm) of a discharge port (needle) of a nozzle and the diameter (mm) of a bead.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C08F 2/46 C08J 9/28

Claims (6)

(57) [Claims] 1. A monomer and / or oligomer (A) which can be polymerized by irradiation with an energy ray and compatible with or dissolved in the monomer and / or oligomer (A), or the monomer and / or oligomer (A) A phase separating agent which is dissolved in a homogeneous solution of a solvent and a solvent and which is not compatible with a polymer formed by irradiating the monomer and / or oligomer (A) with energy rays, and which is inert to energy rays ( B) and a uniform polymerizable solution is discharged in the form of droplets, irradiated with energy rays, and then the phase-separating agent (B) and unreacted polymerizable solution are removed. Method for producing porous beads. 2. The method according to claim 1, wherein the polymerizable solution is extruded from the nozzle under conditions that form a droplet during free fall. 3. A method for extruding a polymerizable solution from a nozzle, comprising:
The shear rate between the polymerizable solution and the nozzle is 10 to 350,000
3. The method according to claim 1, wherein the production method is sec-1. 4. A method for extruding a polymerizable solution from a nozzle, comprising:
The shear rate between the polymerizable solution and the nozzle is 360,000 to 10
3. The method according to claim 1, wherein the production time is 00000 sec-1. 5. The process according to claim 3, wherein 1 to 5 parts by weight of the phase separation agent (B) is used per 1 part by weight of the monomer and / or oligomer (A). 6. energy ray method according to any one of claims 1 to 5 which is ultraviolet or electron beam.