JP2007191512A - Manufacturing process of porous bead - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing process of porous beads which does not necessitate the irradiation of energy radiations and improves manufacturing efficiency. <P>SOLUTION: The polymer solution storage 2 contains at least two kinds of polymers having a number-average molecular weight of ≥10,000 and different coagulation values and dissolved in a solvent compatible with both of the polymers. The coagulation liquid tank 4 contains a coagulation liquid containing a non-solvent. The polymer solution is dripped from the polymer solution storage 2 into the coagulation liquid tank 4 through the nozzle 3. The polymer solution coagulates in the form of a drop in the coagulation liquid to produce the porous beads. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing porous beads that can be used for body fluid treatment, water treatment and the like.

  A porous bead is a granular porous body having pores formed on the surface and inside thereof. In the fields of food industry, pharmaceutical industry, wastewater treatment, artificial organs, medicine, etc., removal of proteins, colloids, bacteria, etc. Used for purposes such as recovery, adsorption removal of harmful gases, decolorization, recovery and removal of harmful substances in water or blood (endotoxins, blood cells, etc.), collection of heavy metals, and carriers for immobilizing enzymes and bacterial cells ing.

As a method for producing porous beads, an oil-in-water emulsion polymerization method is proposed in Japanese Patent Application Laid-Open No. 50-12176. Specifically, an oil-in-water emulsion is formed by stirring a high-speed, long-time stirring solution of a homogeneous mixed solution of oil-based polysynthetic monomer and benzene and water containing a dispersant, such as ionizing radiation or actinic rays. It has been proposed to produce porous beads by polymerizing an oil-in-water emulsion by irradiating energy rays. Further, JP-A-6-248107 discloses that a monomer and / or oligomer is dissolved in a solvent together with a phase separation agent, and this solution is discharged in the form of droplets, and the solution is polymerized by irradiating energy rays. It has been proposed to produce quality beads.
Japanese Patent Laid-Open No. 50-12176 JP-A-6-248107

  However, the porous bead manufacturing methods described in the above patent documents all require that an energy beam be irradiated to the porous bead manufacturing stock solution. For this reason, it is difficult to produce porous beads with simple equipment, leaving room for improvement in the production efficiency of porous beads.

  This invention is made | formed in view of such a situation, and it aims at providing the manufacturing method of the porous bead which can aim at the improvement of manufacturing efficiency, without requiring irradiation of an energy ray.

  The present invention has been proposed in order to achieve the above object, and in the present invention, at least two kinds of polymers having a number average molecular weight of 10,000 or more and different coagulation values are added to each polymer. A method for producing a porous bead, which is produced by dissolving in a compatible solvent and coagulating the polymer solution in a coagulating liquid containing a non-solvent in a droplet state.

  In the present invention, the coagulation value is used in the method for producing porous beads while keeping a solution obtained by dissolving 1 g of polymer in 50 g of the solvent used in the method for producing porous beads at 50 ° C. and stirring the solution. The coagulating liquid is added to the solution little by little, and the amount of coagulating liquid added (mL) at the time when the polymer starts to precipitate in the solution (when the solution becomes cloudy by visual observation).

  In the second aspect, the coagulation value of one of the two polymers is 1 to 15 mL, the coagulation value of the other polymer is 3 mL or more, and the difference in coagulation value of each polymer The method for producing porous beads according to claim 1, wherein is 2 mL or more.

  According to a third aspect of the present invention, there is provided the porous bead manufacturing method according to the first or second aspect, wherein the total polymer content of the polymer solution is set to 10 to 30% by mass.

  The solvent according to claim 4, wherein the solvent compatible with the polymer is N-methyl-2-pyrrolidone, and the non-solvent is water. It is a manufacturing method of the porous bead in any one.

  The method according to any one of claims 1 to 4, wherein the two kinds of polymers described above are a polyarylate resin and a polysulfone resin. It is.

  The method according to any one of claims 1 to 4, wherein both of the two kinds of polymers described above are polysulfone resins. .

  The method according to any one of claims 1 to 4, wherein the two kinds of polymers described above are a polysulfone resin and polyvinylpyrrolidone. is there.

  In the method according to claim 8, the mixing ratio of the two kinds of polymers described above is set to 0.1 to 10, and the porous beads according to any one of claims 5 to 7 are manufactured. Is the method.

According to the present invention, the following excellent effects can be obtained.
That is, at least two types of polymers having a number average molecular weight of 10,000 or more and different coagulation values are dissolved in a solvent compatible with each polymer, and the polymer solution is coagulated with a non-solvent in a droplet state. Since the porous beads are produced by solidification in the liquid, the porous beads can be produced by a simple operation. Therefore, the production efficiency of porous beads can be improved. Moreover, it is not necessary to irradiate the energy beam with an energy beam irradiation device or the like in the porous bead manufacturing process, and as a result, the porous bead can be manufactured with simple equipment. Furthermore, there is no possibility that the performance of the polymer will be impaired by irradiation with energy rays. Therefore, when a polymer excellent in heat resistance and chemical resistance is used as a raw material, porous beads excellent in heat resistance and chemical resistance can be easily produced.

Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings. FIG. 1 is a schematic view of a production apparatus for producing porous beads.
As shown in FIG. 1, a porous bead manufacturing apparatus 1 (hereinafter simply referred to as a manufacturing apparatus 1) includes a polymer solution reservoir 2, a nozzle 3 connected to the polymer solution reservoir 2, and the nozzle 3 And a coagulating liquid tank 4 disposed below the main body.

  The polymer solution storage unit 2 is for storing a polymer solution that is a raw material for porous beads. The polymer solution is prepared by dissolving a plurality of (two types in this embodiment) polymers having different coagulation values in a solvent having compatibility with each polymer. Here, the mixing ratio (weight ratio A / B) of the polyester resin (A) and the polysulfone resin (B) is set in the range of 0.1 to 10, and the content (A + B) of both polymers is 10. A polymer solution is prepared by dissolving in an organic solvent (solvent) so as to be set to ˜30 mass%.

  In addition, the polyester-type resin in this embodiment is a polyarylate resin which has a repeating unit represented by following formula (1).

  The polysulfone-based resin is a polysulfone resin having at least one of the repeating unit represented by the formula (2) and the repeating unit represented by the formula (3).

  Moreover, it is preferable that the polymer melt | dissolved in a polymer solution is 10000 or more in molecular weight (for example, number average molecular weight), and sets a coagulation number in the range of 1-15 mL. The coagulation value in the present invention is determined by maintaining the solution of 1 g of polymer dissolved in 50 g of the solvent used in the method for producing porous beads of the present invention at 50 ° C. and stirring the solution while stirring the solution. It is defined by the amount (mL) of the coagulation liquid added at the time when the coagulation liquid (described later) used in the production method is added to the solution little by little and the polymer starts to precipitate in this solution (when the solution becomes cloudy by visual observation). The The polyarylate resin has a coagulation value of 3.7 mL, and the polysulfone resin has a coagulation value of 4.7 mL. Therefore, the difference in coagulation number of each polymer is set to 1.0 mL. The molecular weight (number average molecular weight) of the polyarylate resin is 25,000, and the molecular weight (number average molecular weight) of the polysulfone resin is 27,000.

  Furthermore, the organic solvent is not particularly limited as long as it is a solvent compatible with the polyester-based resin and the polysulfone-based resin. For example, N-methyl-2-pyrrolidone, tetrahydrofuran, dioxane, dimethylformamide, dimethylacetamide, etc. Can be used. Among these, N-methyl-2-pyrrolidone can be most preferably used.

  The nozzle 3 is for discharging the polymer solution in the polymer solution reservoir 2 in the form of droplets, and the base end (upper end in FIG. 1) of the nozzle 3 is connected to the polymer solution reservoir 2 with the pipe 5 and Connection is made via a liquid feed valve 6. In the present embodiment, the nozzle 3 is disposed at a position lower than the polymer solution storage unit 2, and the nozzle 3 is changed based on the head difference between the polymer solution in the nozzle 3 and the polymer solution in the polymer solution storage unit 2. Although the polymer solution is discharged, the present invention is not limited to this. For example, the nozzle 3 may be disposed above the polymer solution storage unit 2, a liquid feed pump may be provided in the middle of the pipe 5, and the polymer solution may be discharged from the nozzle 3 by the lift of the liquid feed pump.

  The coagulating liquid tank 4 is for storing a coagulating liquid for coagulating the polymer solution. As the coagulation liquid, a mixed solvent obtained by mixing an organic solvent used for resin dissolution with water as a non-solvent is preferable to water alone. This is because it is easier to form a uniform fibril structure when a mixed solvent is used. As the organic solvent to be mixed, a good solvent for the resin, for example, N-methyl-2-pyrrolidone, tetrahydrofuran, dioxane, dimethylformamide, dimethylacetamide and the like can be used. Among these, N-methyl-2-pyrrolidone can be most preferably used.

  In order to manufacture porous beads in such a manufacturing apparatus 1, first, the polymer solution prepared in the polymer solution storage unit 2 is stored and the coagulating liquid is stored in the coagulating liquid tank 4. When the polymer solution or the coagulating liquid is stored in the manufacturing apparatus 1, the liquid feeding valve 6 is slightly opened and the polymer solution is discharged from the nozzle 3 in the form of droplets. When the polymer solution discharged from the nozzle 3 is dropped into the coagulation liquid tank 4, the polymer in the polymer solution coagulates in the coagulation liquid. At this time, the solidification rate of each polymer differs due to the different solidification values. That is, there is a time difference until each polymer is precipitated in the coagulation liquid. Then, the polymer with a low coagulation value first aggregated and started to precipitate. However, if the polymer with a high coagulation value is still in a dissolved state, the polymer with a low coagulation value is prevented from moving by the polymer with a high coagulation value. Rarely, the agglomeration rate is lower than the agglomeration rate when a polymer having a low coagulation value is used alone. This makes the entire polymer system unstable and causes non-uniform aggregation. As a result, a large number of pores are formed in the solidified polymer, and porous beads are produced (manufactured). If the porous beads are generated in the coagulation liquid tank 4, the porous beads are scooped up from the coagulation liquid tank 4, and the porous beads are washed with purified water and dried.

  Porous beads (polymer beads) produced in this way are provided with a dense layer in a state of covering the surface, and pores having an average pore diameter of less than 100 nm (specifically, pores of 3 to 50 nm) in the dense layer. Form. Further, the pores gradually increase from the dense layer toward the center of the porous bead, and an internal cavity having a large hole is formed at the center of the porous bead.

  Thus, in this invention, since a polymer solution is dripped at a coagulating liquid and a porous bead is manufactured, a porous bead can be manufactured by a simple operation | work. Therefore, the production efficiency of porous beads can be improved. In the above-described method for producing porous beads, it is not necessary to polymerize the polymer by irradiating energy rays with an energy ray irradiating apparatus or the like, and as a result, the porous beads can be produced with simple equipment. Furthermore, there is no possibility that the performance of the polymer will be impaired by irradiation with energy rays. Therefore, by preparing a polymer solution using a polymer with excellent heat resistance and chemical resistance, and dropping this polymer solution into the coagulation liquid, it is possible to easily produce porous beads with excellent heat resistance and chemical resistance. Can do. Then, if the size of the droplet of the polymer solution is simply adjusted by changing the setting of the diameter of the nozzle 3, porous beads having a desired size can be easily manufactured.

  In the above embodiment, the polymer solution is prepared using the polyarylate resin and the polysulfone resin, but the present invention is not limited to this. For example, two types of polysulfone resins having different coagulation values may be used. For example, polyether sulfone resin and polysulfone resin may be used.

  Moreover, in the said embodiment, it originates in the coagulation | solidification value of a polymer being different, a nonuniform aggregation of a polymer is produced, As a result, a porous bead can be produced | generated (manufactured). For this reason, the larger the difference between the coagulation values of the polymers, the better. Specifically, it is preferable that the difference in coagulation value of each polymer is set to 2 mL or more.

  Furthermore, as the polymer having a different coagulation value, one having a coagulation value of one polymer of 1 to 15 mL and a coagulation value of the other polymer of 3 mL or more may be used. For example, polysulfone resin (coagulation value 4.7 mL) which is a polysulfone resin and polyvinylpyrrolidone (coagulation value is infinite) which is a hydrophilic polymer may be used. If a polymer bead is mixed with polyvinylpyrrolidone to produce a porous bead, hydrophilicity can be imparted to the porous bead. Therefore, the biocompatibility of the porous beads can be improved by hydrophilization.

  And in the said embodiment, although the polymer solution was prepared using two types of polymers from which a coagulation value differs, this invention is not limited to this. That is, if a polymer solution is prepared using a plurality of polymers having different coagulation values, three or more types of polymers may be dissolved in the polymer solution. A small amount of non-solvent (such as water) may be added to the polymer solution. If the amount of the non-solvent added to the polymer solution is adjusted and this polymer solution is dropped into the coagulation liquid, the pore diameter formed in the porous beads can be adjusted, which is preferable.

  Furthermore, in the said embodiment, although the polymer solution was dripped from the nozzle 3 to the coagulation liquid tank 4, this invention is not limited to this. For example, a spray nozzle is connected to the polymer solution storage unit 2 and a plurality of jet nozzles with extremely small diameters are provided in the spray nozzle so that the polymer solution can be sprayed into fine particles, and the polymer solution sprayed from the spray nozzle is solidified. You may spray on the liquid level of a liquid. Thus, if the polymer solution discharged from the spray nozzle is solidified by the coagulation liquid, a large amount of fine porous beads can be produced. Further, the tip of the nozzle 3 is disposed in the coagulating liquid stored in the coagulating liquid tank 4, and in this state, the polymer solution is discharged from the nozzle 3 to make the polymer solution into droplets and coagulate in the coagulating liquid. Also good.

  The fine structure of the porous beads (specifically, the dense layer) can be changed by selectively adjusting the type of polymer dissolved in the polymer solution, the temperature or concentration of the coagulation liquid, and the like. Thereby, the size of the pores in the porous beads and the density at which the pores are formed can be adjusted, and porous beads having a desired specific surface area can be easily produced.

Next, the present invention will be further described with reference to examples of the present invention.
In Example 1, polyethersulfone resin (grade 4800P, coagulation value 8.4 mL, number average molecular weight 21,000) and polyarylate resin (coagulation value 3.7 mL, number average molecular weight 25,000) were mixed with N-methyl. A polymer solution was prepared by dissolving in -2-pyrrolidone. The mass mixing ratio of the polyethersulfone resin, polyarylate resin, and N-methyl-2-pyrrolidone was set to 7.5: 7.5: 85.0. Further, a mixture of 55% N-methyl-2-pyrrolidone in water was used as a coagulation liquid.

  Furthermore, the nozzle 3 of the manufacturing apparatus 1 was set to a cylindrical shape having an inner diameter of 0.19 mm and an outer diameter of 0.36 mm, and was arranged so as to be separated from the coagulating liquid surface of the coagulating liquid tank 4 by about 20 cm.

Such a polymer solution, a coagulation liquid, and the manufacturing apparatus 1 were prepared, the polymer solution was stored in the polymer solution storage unit 2, and the coagulation liquid was stored in the coagulation liquid tank 4. Then, at room temperature, the liquid supply valve 6 was converted to an open state in this storage state, and the polymer solution in the polymer solution storage unit 2 was dropped into the coagulation liquid from the nozzle 3. As a result, as shown in FIG. 2A, porous beads having a spherical shape with an outer diameter of about 2 mm were obtained. In addition, a large number of pores were confirmed on the surface of the porous beads as shown in FIG. And as a result of measuring the specific surface area of the porous bead obtained in the present Example, the value was 4.92 m < ² > / g.

  In Example 2, polyethersulfone resins (grade 4800P, coagulation value 8.4 mL, number average molecular weight 21,000) and polysulfone resins (coagulation value 4.7 mL, number average molecular weight 27,000) having different coagulation values were used. Were dissolved in N-methyl-2-pyrrolidone to prepare a polymer solution, and the polymer solution was dropped into the coagulation liquid in the same procedure as in Example 1. Furthermore, in Example 3, polysulfone resins having different coagulation values (coagulation value 4.7 mL) and polyvinylpyrrolidone (coagulation value infinite, number average molecular weight 14,000 or 350,000) were mixed with N-methyl-2-pyrrolidone. A polymer solution was prepared by dissolving in the solution, and the polymer solution was dropped into the coagulation liquid in the same procedure as in Example 1. As a result, in any of the examples, it was confirmed that pores were formed in the coagulated beads and that porous beads could be produced.

  In the comparative example, a polyethersulfone resin (grade 4800P, coagulation value 8.4 mL, number average molecular weight 21,000) and polymethyl methacrylate sheet resin (coagulation value 8.4 mL, number average) having the same coagulation value are used. (Molecular weight 200,000) was dissolved in N-methyl-2-pyrrolidone to prepare a polymer solution, and the polymer solution was dropped into the coagulation liquid in the same procedure as in Example 1. As a result, in the comparative example in which the coagulation values of the two kinds of polymers are equal, it was confirmed that no pores were formed in the coagulated beads, and porous beads could not be produced. Table 1 shows the difference in coagulation value and the production results in each Example and Comparative Example.

It is the schematic of a porous bead manufacturing apparatus. It is an electron micrograph of the porous bead in an Example, (a) is a whole photograph, (b) is an enlarged photograph of the surface.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Porous bead manufacturing apparatus 2 Polymer solution storage part 3 Nozzle 4 Coagulating liquid tank 5 Piping 6 Liquid feeding valve

Claims (8)

  In a coagulation solution in which at least two polymers having a number average molecular weight of 10,000 or more and different coagulation values are dissolved in a solvent compatible with each polymer, and the polymer solution is in a droplet state and contains a non-solvent A method for producing a porous bead, which is produced by coagulation with an aqueous solution.   Among the two kinds of polymers, the coagulation value of one polymer is 1 to 15 mL, the coagulation value of the other polymer is 3 mL or more, and the difference in coagulation value of each polymer is 2 mL or more, The method for producing a porous bead according to claim 1.   The method for producing a porous bead according to claim 1 or 2, wherein the total polymer content of the polymer solution is set to 10 to 30% by mass.   The porous bead according to any one of claims 1 to 3, wherein the solvent having compatibility with the polymer is N-methyl-2-pyrrolidone, and the non-solvent is water. Production method.   The method for producing porous beads according to any one of claims 1 to 4, wherein the two kinds of polymers are a polyarylate resin and a polysulfone resin.   The method for producing porous beads according to any one of claims 1 to 4, wherein both of the two kinds of polymers are polysulfone resins.   The method for producing a porous bead according to any one of claims 1 to 4, wherein the two kinds of polymers are a polysulfone resin and polyvinylpyrrolidone. The method for producing a porous bead according to any one of claims 5 to 7, wherein a mixing ratio of the two kinds of polymers described above is set to 0.1 to 10.

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