JP2007246660A - Polymer bead and method for producing the same and apparatus for forming droplet for producing polymer bead - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing polymer beads by which the polymer beads having a narrow particle size distribution can stably be produced with high productivity over a long period. <P>SOLUTION: The method for producing the polymer beads comprises the following steps. A step of arranging a dispersion medium 41 on one surface side of a perforated plate 2 in which protruding parts 4 protruding from the inner peripheral surface of through-holes 5 to the outside of the surface 3a of a plate 3 provided with the plurality of fine through-holes 5 are extendedly installed on one surface of the plate 3 and arranging a monomer composition 42 on the other surface side of the perforated plate 2, jetting the monomer composition 42 through the through-holes 5 of the perforated plate 2 into the dispersion medium 41 on the opposite side and thereby forming droplets 40 of the monomer composition in the dispersion medium 41 and a step of applying heat to the dispersion medium 41 containing the droplets 40 or irradiating the dispersion medium with light, thereby polymerizing the monomer composition and affording the polymer beads. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing polymer beads having a narrow particle size distribution used for, for example, chromatography carriers and pharmaceutical purification, and a droplet generator for producing the polymer beads.

  Polymer beads are widely used as, for example, ion exchange resins, chromatography carriers, microcapsules and the like.

  For example, when polymer beads are used as a chromatography carrier, the polymer beads are used by being packed in a column, and the liquid passes through the packed polymer bead layer. At this time, if the particle size of the polymer beads is not uniform, the passage resistance of the passing liquid increases, the liquid flow becomes uneven, and the separation efficiency of the column decreases. Therefore, the polymer beads are required to have a substantially uniform particle size in order to minimize the liquid passage resistance.

  Conventionally, various methods have been proposed for the production of polymer beads. For example, Patent Document 1 proposes a method in which an oil phase (dispersed phase liquid) is discharged into an aqueous phase (continuous phase liquid) through a perforated plate whose through hole has an oval or rectangular shape. Thus, it is described that polymer beads having a narrow particle size distribution can be produced by making the shape of the ejection hole an oval or a rectangle.

  Further, in Patent Document 2, when the oil phase (dispersed phase liquid) is extruded into the aqueous phase (continuous phase liquid) through the perforated plate, the shape of the through holes in the perforated plate is rectangular, L-shaped, T-shaped, H It is described that a polymer bead having a narrow particle size distribution can be obtained by making it non-circular such as a letter shape.

As a method for obtaining droplets by pumping an oil phase through a nozzle into a water phase, for example, an example in which benzene is jetted into water through a nozzle is known (see Non-Patent Document 1). There are known examples in which an oil phase such as benzene is jetted through an injection needle in the phase and analyzed (see Non-Patent Document 2). The oil phase is ejected into the aqueous phase, and the produced droplets are not actively pulled off from the perforated plate by the flow of the aqueous phase as in Patent Documents 1 and 2, so that the droplets are not obtained.
JP 2001-294602 A (Claim 1, paragraph 0007) JP 2002-119841 (Claim 6, paragraphs 0027, 0028, 0041) “Chemical Engineering Handbook (4th revised edition)”, Maruzen Co., Ltd., p. 788 “Chemical Engineering Papers,” Chemical Society of Japan, 1979, Vol. 5, No. 3, p. 288-291

  In the above conventional manufacturing method, when the dispersed phase liquid coming out of the through hole becomes a certain size, it is separated from the through hole and becomes a uniform-sized droplet and moves downstream. , Droplets tend to cling to the surface of the perforated plate near the through-holes, etc., that is, it is difficult for the droplets to detach smoothly from the perforated plate, and this makes polymer beads with a sufficiently narrow particle size distribution It was difficult to do. That is, when the droplets cling to the surface of the perforated plate in the vicinity of the through-hole, a large volume droplet grows and is released into the aqueous phase, or the clinging causes the droplet to extend long. Droplets that do not depend on the hole diameter are formed when the droplets are separated from the through-hole and separated into two droplets, a small droplet on the tail side and a droplet on the front side. For this reason, there is a problem that the particle size distribution of the polymer beads is widened.

  The present invention has been made in view of such a technical background, and is capable of producing polymer beads having a narrow particle size distribution (substantially uniform particle size distribution) over a long period of time with high productivity. And a droplet generating apparatus for producing the polymer beads.

  In order to achieve the above object, the present invention provides the following means.

[1] The one of the perforated plates in which a protruding portion that protrudes outward from the surface of the plate extends from the inner peripheral surface of the through hole on one surface of the plate provided with a number of fine through holes. Disposing a dispersion medium on the other surface side, disposing a monomer composition on the other surface side of the porous plate, and ejecting the monomer composition into the dispersion medium on the opposite side through the through holes of the porous plate. Generating droplets of the monomer composition in the dispersion medium,
And a step of polymerizing the monomer composition by applying heat or irradiating light to the dispersion medium containing the droplets to obtain polymer beads.

  [2] The method for producing polymer beads as recited in the aforementioned Item 1, wherein the protrusion is cylindrical.

  [3] The method for producing polymer beads according to item 1 or 2, wherein the diameter of the through hole is 1 to 300 μm, and the distance from the surface of the porous plate to the tip edge of the protruding portion is 8 to 20 μm.

  [4] The method for producing polymer beads according to item 1 or 2, wherein the diameter of the through hole is 1 to 300 μm, and the distance from the surface of the porous plate to the tip edge of the protruding portion is 10 to 15 μm.

  [5] The diameter of the through hole is 1 to 300 μm, and the thickness of the tip edge of the protrusion is not more than 5 times the diameter of the through hole (the configuration in which the thickness of the tip edge is substantially zero). (5) The method for producing polymer beads according to any one of (1) to (4) above.

  [6] The diameter of the through-hole is 1 to 300 μm, and the thickness of the tip edge of the protrusion is not more than 1 times the diameter of the through-hole (the configuration where the thickness of the tip edge is substantially zero) (5) The method for producing polymer beads according to any one of (1) to (4) above.

  [7] The method for producing polymer beads as described in any one of [1] to [6] above, wherein a metal plate is used as the plate constituting the porous plate.

  [8] The method for producing polymer beads according to any one of items 1 to 6, wherein a stainless plate, a nickel plate, or a molybdenum plate is used as the plate constituting the porous plate.

  [9] The method for producing polymer beads according to any one of items 1 to 6, wherein the porous plate is a porous nickel plate manufactured by an electroforming method.

  [10] A polymer bead produced by the production method according to any one of items 1 to 9.

  [11] Separated by a perforated plate in which a protruding portion that protrudes outward from the surface of the plate is extended from one surface of the plate provided with a number of fine through holes from the inner peripheral surface of the through hole. A droplet generator for producing polymer beads comprising a mixing tank having two tanks.

  [12] The droplet generator for producing polymer beads according to [11], wherein the diameter of the through hole is 1 to 300 μm, and the distance from the surface of the porous plate to the leading edge of the protrusion is 8 to 20 μm.

  [13] The diameter of the through hole is 1 to 300 μm, and the thickness of the tip edge of the protrusion is not more than 5 times the diameter of the through hole (the configuration in which the thickness of the tip edge is substantially zero). The droplet generator for producing polymer beads as described in 11 or 12 above.

  [14] The droplet generator for producing polymer beads according to any one of items 11 to 13, wherein a metal plate is used as a plate constituting the porous plate.

  [15] The droplet generating apparatus for producing polymer beads according to any one of the above items 11 to 13, wherein a stainless plate, a nickel plate, or a molybdenum plate is used as the plate constituting the porous plate.

  [16] The droplet generator for producing polymer beads as described in any one of [11] to [13], wherein the porous plate is a porous nickel plate manufactured by an electroforming method.

  In the invention of [1], since the monomer composition is ejected into the dispersion medium on the opposite side through the through hole of the perforated plate, the monomer composition that has come out of the through hole is separated from the through hole when it reaches a certain size. However, at this time, the leading edge of the inner peripheral surface of the through hole is extended by the extension of the protruding portion on the side where the dispersion medium exists in the perforated plate. Since the liquid protrudes outward from the surface of the perforated plate, the droplets are smoothly separated from the perforated plate without moving to the surface in the vicinity of the through-holes and moved downstream, and thereby the dispersion medium. A droplet having a uniform diameter can be generated therein. Thereafter, polymer beads are narrowed (substantially uniform in particle size distribution) by polymerizing the monomer composition by applying heat or irradiating light to the dispersion medium containing droplets. In addition, even if dirt adheres to the surface of the porous plate near the through hole due to long-term use, in this manufacturing method, the tip edge of the inner peripheral surface of the through hole protrudes outward from the surface of the porous plate. Therefore, the droplets are smoothly separated from the perforated plate without clinging to the surface in the vicinity of the through-holes, and moved to the downstream side, thereby stably producing a polymer bead having a narrow particle size distribution over a long period of time. It can be manufactured with sex.

  In the invention [2], since the protruding portion is formed in a cylindrical shape, droplets having a uniform diameter can be generated in the dispersion medium.

  In the invention of [3], the distance from the surface of the perforated plate to the leading edge of the protruding portion (the protruding height of the protruding portion) is set to 8 μm or more, so that the liquid droplets separated from the through hole can pass through the through hole. Polymer beads with a narrower particle size distribution can be sufficiently prevented from clinging to nearby surfaces, etc., and the protrusion height of the protrusion is set to 20 μm or less, and the flow of the dispersion medium is unlikely to be turbulent. Can be stably produced over a long period of time.

  In the invention of [4], the distance from the surface of the perforated plate to the leading edge of the protruding portion (the protruding height of the protruding portion) is set to 10 μm or more, so that the liquid droplets separated from the through hole can pass through the through hole. It is possible to more sufficiently prevent clinging to a nearby surface and the like, and since the protrusion height of the protrusion is set to 15 μm or less and the flow of the dispersion medium is less likely to be turbulent, the particle size distribution is further improved. Narrow polymer beads can be produced stably over a long period of time.

  In the invention of [5], since the thickness of the tip edge of the protrusion is not more than 5 times the diameter of the through-hole, the monomer composition coming out of the through-hole is detached from the through-hole when it reaches a certain size. It becomes what forms a droplet, ie, the detachability from the through-hole of a monomer composition can be improved. This makes it possible to produce polymer beads with a narrower particle size distribution (having a sharper particle size distribution).

  In the invention of [6], since the thickness of the tip edge of the protrusion is not more than 1 times the diameter of the through-hole, the monomer composition coming out of the through-hole immediately leaves the through-hole when it reaches a certain size. Thus, droplets can be formed, that is, the detachability of the monomer composition from the through holes can be further improved. Thereby, polymer beads having a narrower particle size distribution (having a sharper particle size distribution) can be produced.

  In the invention of [7], since the metal plate is used as the plate constituting the porous plate, the strength is high and the durability is excellent, and a through-hole having a uniform diameter can be easily formed.

  In the invention of [8], since a stainless plate, a nickel plate or a molybdenum plate is used as the plate constituting the porous plate, it is possible to reduce the thickness of the porous plate in order to achieve a more uniform particle size. Thus, the particle size can be further uniformed.

  In the invention of [9], a nickel porous plate manufactured by an electroforming method is used, and the surface of the porous nickel plate formed by such an electroforming method is subjected to a hydrophilic treatment, whereby droplets are obtained. Can be sufficiently prevented from clinging to the surface in the vicinity of the through-holes of the perforated plate, and polymer beads having a more uniform particle size distribution can be produced.

  In the invention of [10], polymer beads having a narrow particle size distribution (almost uniform particle size distribution) are provided.

  In the droplet generating device according to the invention of [11], a protruding portion that protrudes outward from the surface of the plate from the inner peripheral surface of the through hole extends on one surface of the plate provided with a large number of fine through holes. Since a mixing tank having two tanks separated by a perforated plate is provided, a dispersion medium is disposed on the one surface side of the perforated plate (side on which the protruding portion is extended), When the monomer composition is arranged on the other surface side and the monomer composition is ejected into the dispersion medium on the opposite side through the through holes of the perforated plate, the monomer composition coming out of the through holes has a certain size. Then, it is pulled away from the through-hole and becomes a droplet due to the effect of surface tension and moves downstream.At this time, the extension of the protrusion on the side where the dispersion medium exists in the perforated plate, Since the leading edge of the surface protrudes outward from the surface of the perforated plate, the droplet And smoothly disengaged from the porous plate without stick Matowari the surface of the through-holes near it shall be moved to the downstream side, thereby making it possible to produce droplets of uniform size in the dispersion medium. Thereafter, when the monomer composition is polymerized by applying heat or irradiating light to the dispersion medium containing droplets, polymer beads having a narrow particle size distribution (almost uniform particle size distribution) are obtained. Also, in this droplet generator, the tip edge of the inner peripheral surface of the through hole protrudes outward from the surface of the perforated plate, so that dirt adheres to the surface in the vicinity of the through hole in the perforated plate due to long-term use. Even if it occurs, the droplets smoothly leave the perforated plate without clinging to the surface in the vicinity of the through-holes and move to the downstream side. And it can manufacture with high productivity.

  In the invention of [12], the distance from the surface of the perforated plate to the leading edge of the protruding portion (the protruding height of the protruding portion) is set to 8 μm or more, so that the liquid droplets separated from the through hole can pass through the through hole. Polymer beads with a narrower particle size distribution can be sufficiently prevented from clinging to nearby surfaces, etc., and the protrusion height of the protrusion is set to 20 μm or less, and the flow of the dispersion medium is unlikely to be turbulent. Can be stably produced over a long period of time.

  In the invention of [13], since the thickness of the tip edge of the protrusion is not more than 5 times the diameter of the through-hole, the monomer composition coming out of the through-hole is detached from the through-hole when it reaches a certain size. It becomes what forms a droplet, ie, the detachability from the through-hole of a monomer composition can be improved. This makes it possible to produce polymer beads with a narrower particle size distribution (having a sharper particle size distribution).

  In the invention of [14], since a metal plate is used as a plate constituting the porous plate, the strength is high and the durability is excellent, and a through-hole having a uniform diameter is easily formed.

  In the invention of [15], a stainless plate, a nickel plate, or a molybdenum plate is used as a plate constituting the porous plate, so that the porous plate can be sufficiently thinned to achieve a more uniform particle size. This makes it possible to produce polymer beads with a more uniform particle size.

  In the invention of [16], a nickel porous plate manufactured by an electroforming method is used, and the porous nickel plate formed by such an electroforming method has a high hydrophilicity on the surface. It is possible to more sufficiently prevent clinging to the surface in the vicinity of the through-holes of the perforated plate, and polymer beads having a more uniform particle size distribution can be produced.

  A method for producing polymer beads according to the present invention will be described with reference to the drawings. One embodiment of a droplet generator (1) used in this manufacturing method is shown in FIG. The droplet generator (1) includes a mixing tank (10), a dispersion medium storage tank (31), a monomer composition storage tank (32), and a generated emulsion storage tank (33).

  As shown in FIG. 2, the mixing tank (10) is composed of a dispersion medium flow tank (11) and a monomer composition flow tank (12) separated by a perforated plate (penetrating microreactor) (2). Yes. The perforated plate (penetrating microreactor) (2) has an inner peripheral surface of the through hole (5) on one surface (3a) of the metal plate (3) provided with a number of fine through holes (5). A cylindrical projecting portion (4) projecting outward from the surface (3a) of the metal plate (3) from the end edge of the metal plate (3). The cylindrical protrusion (4) constitutes a part of the inner peripheral surface of the through hole (5). The cylindrical protrusion (4) is made of metal. The perforated plate (2) is arranged so that the surface (3a) on which the protrusion (4) is formed is on the dispersion medium flow tank (11) side (see FIG. 2). That is, on the side of the porous plate (2) where the dispersion medium (41) is present, the projecting portion (4) is provided so that the tip edge (upper edge) of the inner peripheral surface of the through hole (5) is It protrudes outward from the surface (3a). The through hole (5) has a circular shape in plan view, and the protrusion (4) is formed in a cylindrical shape. Further, as shown in FIG. 6, the plurality of through holes (5) are arranged at substantially equal intervals in the central region of the perforated plate (2). In addition, the arrangement | positioning aspect of the said through-hole (5) may be substantially equal intervals, and may be an equal interval, and is not specifically limited.

  One end of a supply pipe (35) is connected to the left opening of the monomer composition flow tank (12), and the other end of the supply pipe (35) is connected to a monomer composition storage tank (32). A pump (38) is disposed in the middle of the supply pipe (35). One end of a supply pipe (34) is connected to the left opening of the dispersion medium flow tank (11), and the other end of the supply pipe (34) is connected to the dispersion medium storage tank (31). A pump (37) is also disposed in the middle of the supply pipe (34). Further, one end of the flow pipe (36) is connected to the right opening of the dispersion medium flow tank (11), and the other end of the flow pipe (36) is connected to the generated emulsion storage tank (33). (See FIG. 1).

  In the present embodiment, since the upper wall constituting the dispersion medium flow tank (11) of the mixing tank (10) is composed of a glass plate (13), the liquid in the dispersion medium flow tank (11) It is possible to observe the generation state of the droplet (40), the presence or absence of clinging of the droplet (40) to the porous plate surface (3a), and the like.

  Thus, the dispersion medium (41) is stored in the dispersion medium storage tank (31), the monomer composition (42) is stored in the monomer composition storage tank (32), and the pumps (37) (38) are stored. Is driven, the dispersion medium (41) is supplied from the dispersion medium storage tank (31) through the supply pipe (34) into the dispersion medium flow tank (11), while the monomer composition storage tank The monomer composition (42) is supplied from (32) into the monomer composition flow tank (12) through the supply pipe (35). That is, as shown in FIG. 2, the dispersion medium (41) is arranged on one side of the porous plate (2), and the monomer composition (42) is arranged on the other side of the porous plate (2). The monomer composition (42) is pressed into the through hole (5) of the perforated plate (2) and ejected into the dispersion medium (41) on the opposite side, whereby the dispersion medium (41) Monomer composition droplets (40) are formed. As shown in FIG. 2, when the monomer composition (42) coming out of the through hole (5) reaches a certain size, it is pulled away from the through hole (5) and becomes a droplet (40) due to the influence of surface tension. It moves to the downstream side (the right side of the drawing), and at this time, the inner periphery of the through hole (5) is formed by the extension of the protrusion (4) on the side where the dispersion medium (41) is present in the porous plate (2). Since the front edge of the surface protrudes outward from the surface (3a) of the porous plate, the liquid droplet (40) is not attached to the surface (3a) in the vicinity of the through-hole (5), etc. 2), and smoothly moves to the downstream side, whereby droplets (40) having a uniform diameter can be generated in the dispersion medium (41). The dispersion medium (41) containing the droplets (40) thus obtained is sequentially stored in the generated emulsion storage tank (33).

  Next, by applying heat or irradiating light to the dispersion medium (41) containing the droplets (40) stored in the generated emulsion storage tank (33), the monomer composition (42) Is polymerized in the dispersed droplet (40) state to obtain polymer beads having a narrow particle size distribution (almost uniform particle size distribution).

  In addition, the structure which laminated | stacked the titanium oxide coat layer (titanium oxide coating layer) on the surface (3a) of the side in which the protrusion part (4) in the said porous plate (2) was formed (side in which a dispersion medium exists) was employ | adopted. May be. Thus, when the titanium oxide coat layer is formed on the surface (3a) on the side where the dispersion medium exists in the porous plate (2), excellent hydrophilicity is imparted. It is possible to sufficiently prevent clinging to the nearby surface (3a) and the like, and the droplet (40) is more smoothly detached from the perforated plate (2), so that a more uniform particle size can be obtained. Polymer beads with a distribution can be produced.

  Further, during the operation of ejecting the monomer composition (42) into the dispersion medium (41) on the opposite side through the through holes (5) of the perforated plate (2), the monomer composition (42) enters the dispersion medium flow tank (11). You may make it irradiate with ultraviolet light. That is, the titanium oxide coating layer formed on the porous plate (2) may be irradiated with ultraviolet light. By irradiating the titanium oxide coat layer with ultraviolet light in this way, the surface of the titanium oxide coat layer can be decomposed and removed by the photocatalytic action of titanium oxide, so that the surface on the dispersion medium side of the porous plate (2) The decrease in hydrophilicity of (3a) can be sufficiently prevented, that is, high hydrophilicity can be maintained over a long period of time.

  The thickness of the titanium oxide coat layer is not particularly limited, but is preferably 0.1 to 10 μm. Within such a thickness range, the hydrophilicity of the surface of the porous plate (2) can be sufficiently increased, and the photocatalytic action can be sufficiently exhibited. Especially, it is more preferable that the thickness of the titanium oxide coat layer is 0.3 to 5 μm.

  Further, during the operation of injecting the monomer composition (42) into the dispersion medium (41) on the opposite side through the through hole (5) of the porous plate (2), the porous plate (2 ) May be given vibration. If such vibration is applied, the monomer composition (42) coming out of the through hole (5) is immediately released from the through hole (5) to form a droplet (40) when it reaches a certain size. Therefore, polymer beads with a narrower particle size distribution can be produced.

  The frequency of vibration when applying vibration to the porous plate (2) by the vibrator is preferably set to 5 to 100 Hz, and particularly preferably 20 to 50 Hz. Further, the vibration width is preferably 1 mm or less, and particularly preferably 0.5 mm or less. By setting the vibration width to 1 mm or less, it is possible to prevent the generated droplet (40) from being crushed due to the influence of vibration. In addition, the direction of vibration when applying vibration to the porous plate (2) by the vibrator is not particularly limited. For example, the direction may be parallel to the surface of the porous plate (2). It may be in the normal direction.

  In this invention, it is preferable that the flow of the dispersion medium (41) generated in the dispersion medium flow tank (11) is a laminar flow. Thereby, the particle size of the produced | generated droplet (40) can be made more uniform, and the particle size distribution of the polymer bead obtained by extension can be further narrowed by extension. When the flow of the dispersion medium (41) generated in the dispersion medium flow tank (11) is turbulent, the particle size distribution of the resulting polymer beads becomes wide, which is not preferable.

  The diameter (D) of the through hole (5) is generally set to 1 to 300 μm. When the diameter (D) of the through-hole (5) is 1 to 300 μm, the protrusion height (H) of the protrusion (4) is the protrusion from the surface (3a) of the porous plate (2). The distance (H) to the tip edge (4a) of the part (4) is preferably set to 8 to 20 μm (see FIG. 3). If it is less than 8 μm, it is not preferable because the effect of preventing droplets separated from the through hole (5) from clinging to the surface (3a) in the vicinity of the through hole cannot be obtained. On the other hand, if it exceeds 20 μm, the flow of the dispersion medium (41) tends to be turbulent, which is not preferable. Especially, it is more preferable that the protrusion height (H) of the protrusion (4) is set to 10 to 15 μm.

  When the diameter (D) of the through hole (5) is 1 to 300 μm, the thickness (W) of the tip edge (4a) of the protrusion (4) is the diameter of the through hole (5). It is preferably set to 5 times or less of (D) (see FIG. 3). If it exceeds 5 times, the effect of improving the detachability from the through-hole (5) of the monomer composition cannot be obtained sufficiently, which is not preferable. Especially, it is more preferable that the thickness (W) of the tip edge (4a) of the protrusion (4) is set to be not more than 1 times the diameter (D) of the through hole (5). Thus, the thickness (W) of the tip edge (4a) of the protrusion (4) is preferably set small, for example, the thickness (W) of the tip edge (4a) as shown in FIG. In other words, a configuration of 0 may be adopted.

  When the polymer beads of the present invention are used in, for example, an analytical column, it is desired to shorten the analysis time. Therefore, it is desirable that the pressure at which the liquid sample passes through the column is as small as possible. In order to reduce the pressure of the liquid passing therethrough, it is preferable that the particle size of the polymer beads is monodispersed, that is, the standard deviation of the particle size distribution of the polymer beads is preferably as small as possible. For example, when used in an analytical column, the standard deviation of the particle size distribution of the polymer beads is preferably about 20 μm or less for practical use. In order to achieve this standard deviation of about 20 μm or less, the protrusion height (H) of the protrusion (4) is preferably set to 8 to 20 μm, as is apparent from FIGS. In order to achieve a standard deviation of about 20 μm or less, as is apparent from FIGS. 10 and 11, the thickness (W) of the tip edge (4a) of the protrusion (4) is set to the through hole (5). The diameter (D) is preferably set to 5 times or less. In the case of use in an analytical column, in practice, the standard deviation of the particle size distribution of polymer beads is desirably about 20 μm or less. Conventionally, particles larger than the standard by classification operations such as air classification are used. In the present invention, the protrusion height (H) of the protrusion (4) and / or the tip edge (4a) of the protrusion (4) is dealt with. By setting the thickness (W) within the above-mentioned preferable range, it is possible to cope with it sufficiently (that is, no classification operation is required afterwards). If it deviates from such a suitable range, the time required for the column analysis becomes longer, which is not preferable.

  Further, when the polymer beads of the present invention are used as, for example, a purification gel, in such a case, the liquid is generally not sent by a pump, and the liquid falls between the beads by gravity. In this case, the particle size of the polymer beads is preferably more monodispersed, that is, the standard deviation of the particle size distribution of the polymer beads is preferably about 10 μm or less. In order to achieve this standard deviation of about 10 μm or less, the protrusion height (H) of the protrusion (4) is preferably set to 10 to 15 μm, as is apparent from FIGS. In order to achieve a standard deviation of about 10 μm or less, as is apparent from FIGS. 10 and 11, the thickness (W) of the tip edge (4a) of the protrusion (4) is set to the through hole (5). The diameter (D) is preferably set to be 1 times or less.

  The thickness (W) is a geometric shape dimension set to limit the run-up distance of the droplet (the distance traveled by clinging to the surface of the perforated plate). Therefore, the thickness (W) for realizing narrowing of the particle size distribution is defined by a ratio with the diameter (D) of the through hole (5). On the other hand, the protrusion height (H) of the protrusion (4) defines the limit value at which the droplets cling to the surface of the perforated plate. The value is important.

  The relationship between the diameter (D) of the through-hole (5) and the particle size of the polymer beads to be obtained cannot be uniquely determined because it is affected by physical properties (viscosity), ejection conditions, etc. depending on the composition of the monomer composition. However, in general, the relationship is as follows.

  That is, for example, when the diameter (D) of the through hole (5) is 50 μm, the average particle diameter of the polymer beads is 150 to 180 μm, and the diameter (D) of the through hole (5) is 20 μm. When the average particle diameter of the polymer beads is 50 to 70 μm and the diameter (D) of the through hole (5) is 10 μm, the average particle diameter of the polymer beads is 30 to 40 μm and the diameter of the through hole (5) ( When D) is 3 μm, the average particle diameter of the polymer beads is generally 9 to 12 μm, but is not particularly limited thereto.

  In addition, the cross-sectional shape of the through hole (5) is not particularly limited, and examples thereof include a circular shape, an elliptical shape, a polygonal shape (including a triangular shape and a quadrangular shape), and the like. The cross-sectional shape of the through hole (5) may be the same in the axial direction (thickness direction of the perforated plate) of the hole (5), or may be set to be similar. That is, the vertical cross-sectional shape of the through hole (5) is not particularly limited to the vertical cross-sectional shape as shown in FIG. 3, and for example, the vertical cross-sectional shape as shown in FIG. Can also be adopted. Moreover, when employ | adopting polygonal shape as a cross-sectional shape of the said through-hole (5), in order to suppress disturbing the flow of the jet flow of an oil phase, it is preferable to form the corner | angular part in a smooth curved surface. In the case where the cross-sectional shape of the through hole (5) is not a perfect circle, the diameter (D) of the through hole (5) is a value obtained by (the long diameter of the hole + the short diameter of the hole) / 2. Shall mean.

  Further, the cross-sectional shape of the protrusion (4) is not particularly limited, and examples thereof include a circular shape, an elliptical shape, a polygonal shape (including a triangular shape and a quadrangular shape), and the like. Moreover, the cross-sectional shape may be the same from the base side (base end side) to the front end side of the projecting portion (4), or may be set to be similar. Moreover, when employ | adopting polygonal shape as a cross-sectional shape of the said protrusion part (4), in order to suppress disturbing the flow of a water phase (41), it is preferable to form the corner | angular part in a smooth curved surface.

  The long axis direction of the cylindrical protrusion (4) and / or the long axis direction of the through hole (5) may be substantially perpendicular to the surface (3a) of the perforated plate (2). Alternatively, it may be inclined downstream of the flow of the water phase (41). By setting in this way, the ejection state of the oil phase can be stabilized and droplet formation can also be performed stably.

  The thickness (T) of the porous plate (2) is not particularly limited, but is preferably set to 10 to 500 μm, particularly preferably 30 to 300 μm.

  Moreover, although the space | interval (t) of the through-hole (5) in the said perforated panel (2) is not specifically limited, It is preferable to set to 50-500 micrometers, and a particularly preferable space | interval is 100-400 micrometers. .

  Moreover, the arrangement | positioning form of the through-hole (5) in the said perforated panel (2) is not specifically limited. For example, as shown in FIG. 6, the through holes (5) may be arranged in an aligned state in the vertical and horizontal directions, or may be arranged in a staggered manner.

  Although it does not specifically limit as a board which comprises the said porous plate (2), It is preferable to use a metal plate (3). When the metal plate (3) is used, there is an advantage that the through hole having a uniform diameter can be formed while being easy to process and excellent in durability without being cracked. The metal plate (3) is not particularly limited, but a stainless plate, a nickel plate or a molybdenum plate is preferably used. In this case, a porous plate for realizing a more uniform particle size is used. Thinning is possible. Further, as the porous plate (2), it is particularly preferable to use a porous nickel plate manufactured by an electroforming method (electroforming method). When a hydrophilic treatment is applied to the surface of the porous nickel plate formed by such an electroforming method, the droplets are spread on the surface (3a) in the vicinity of the through hole (5) of the porous plate (2). It is possible to more sufficiently prevent the association.

  As a manufacturing method of the porous plate (2) provided with the through hole (5) having the protruding portion (4) at the opening edge, that is, as the manufacturing method of the porous plate (2) provided with the protruding hole, Although not limited, for example, a method using lithograph and electroforming, a cutting method, a casting method such as die casting, a forging method and the like can be mentioned.

  Examples of the method using lithograph and electroforming include the following methods. First, a mask is placed on the upper surface of the polymer resist (51) laminated on the substrate (50). In this state, exposure is performed by irradiating the mask with X-rays or ultraviolet rays, and then the mask is removed and development processing is performed. -The exposed portion is cleaned and removed by performing a cleaning process, and a mold (52) composed of a base (50) and a resist (51) as shown in FIG. Next, as shown in FIG. 7 (b), a metal is deposited in a plate shape on the upper surface side of the mold (52) by electroforming (or vapor deposition may be used), and then the resist (51) is dissolved using a solution. By dissolving and removing the perforated plate (2) as shown in FIG.

  The ejection speed of the monomer composition (42) into the dispersion medium (41) through the through holes (5) of the porous plate (2) is preferably 0.1 to 50 g / min. By setting to such a range, polymer beads having a narrower particle size distribution can be obtained. Especially, it is more preferable that the ejection speed is set to 1 to 5 g / min. In addition, since the suitable range of the said ejection speed is set in relation to the number of through-holes formed, it is preferable to set the range appropriately according to the number of through-holes formed.

  Further, the flow rate of the dispersion medium (aqueous phase) (41) is not particularly limited, and may be set as appropriate in relation to the ejection speed of the monomer composition (oil phase) (42). For example, the flow rate of the aqueous phase (41) is set to 4 to 12 g / min. Generally, when the flow rate of the aqueous phase (41) is set high, the particle size of the generated droplet (40) becomes small.

  The monomer composition used in the present invention is determined in consideration of the properties of the target polymer beads, and generally includes a composition containing a vinyl monomer, for example, a monofunctional vinyl. Examples of such a compound include a mixture of a polyfunctional vinyl compound (polyvinyl compound), a diluent (precipitating agent), a polymerization initiator and the like as a crosslinking agent, but is not particularly limited to such a composition. .

  Specific examples of the monofunctional vinyl compound include, but are not particularly limited to, styrene, methyl acrylate, acrylonitrile, glycidyl methacrylate, etc. that are insoluble in a dispersion medium. Examples of the diluent include divinylbenzene, ethylene glycol dimethacrylate, and trimethylolpropane triacrylate. Examples of the diluent include toluene, chloroparaffin, dichlorobenzene, trichlorobenzene, alcohols, esters, and the like. As the polymerization initiator, benzoyl peroxide, butyl peroxide, azobisisobutyronitrile and the like, which are generally used for the polymerization reaction of the vinyl compound and are soluble in the polymerization monomer, can be mentioned.

  The dispersion medium used in the present invention is not particularly limited. For example, CMC (carboxymethyl cellulose), PVA (polyvinyl alcohol), polyacrylic acid soda, gelatin, and the like are used as protective colloids in water. What melt | dissolved 0.2-10 mass% etc. are mentioned.

  Next, specific examples of the present invention will be described, but the present invention is not particularly limited to these examples.

<Example 1>
A porous plate (2) made of a nickel plate (3) having a thickness of 50 μm and having 99 through-holes (5) having a diameter (D) of 20 μm was produced by a method using lithograph and electroforming (FIG. 2, 3 and 6). On one side of the perforated plate (2), as shown in FIG. 3, a cylindrical projecting portion projecting outward from the surface (3a) of the nickel plate from the edge of the inner peripheral surface of the through hole (5) ( 4) was extended. The protrusion height (H) of the protrusion (4) was 10 μm, and the thickness (W) of the tip edge (4a) of the protrusion (4) was 50 μm (see FIG. 3). The distance between the through-hole _{(5) (t 1) (} t 2) was 250 [mu] m (see FIG. 6).

  The perforated plate (2) provided with the through hole (5) having the protrusion (4) at the opening edge as described above was produced by the following method. That is, a mask is arranged on the upper surface of the PMMA resist (51) laminated on the substrate (50), and in this state, exposure is performed by irradiating ultraviolet rays from above the mask. Then, the exposed portion was removed by washing to produce a mold (52) composed of a base (50) and a resist (51) as shown in FIG. Next, as shown in FIG. 7 (b), nickel is deposited in a plate shape by electroforming in the recess on the upper surface side of the mold (52), and then the PMMA resist (51) is dissolved and removed using a solution. As a result, a porous plate (2) as shown in FIG. That is, a cylindrical protrusion (4) that protrudes outward from the surface (3a) of the nickel plate (3) extends from the edge of the inner peripheral surface of the circular through hole (5) in plan view. A perforated plate (2) was obtained (see FIG. 3).

  After the perforated plate (2) was ultrasonically cleaned, a droplet generating device (1) as shown in FIG. 1 was constructed using the perforated plate (2). In addition, the space | interval of a perforated plate (2) and a glass plate (13) was 0.3 mm.

  1 L of 5 mass% PVA (polyvinyl alcohol, polymerization degree 500) aqueous solution (water phase) was stored in the dispersion medium storage tank (31). Further, an oil phase obtained by mixing 40 g of divinylbenzene (containing 45% by mass of ethylstyrene), 60 g of toluene, and 1.33 g of AIBN (azobisisobutyronitrile) was stored in the monomer composition storage tank (32). .

  Then, the pumps (37) and (38) of the droplet generating device (1) are driven to allow the monomer composition (42) of the monomer composition flow tank (12) to pass through the through holes (5) of the perforated plate (2). ) And injected into the dispersion medium (41) of the dispersion medium flow tank (11) on the opposite side to form droplets (40) of the monomer composition in the dispersion medium (41). At this time, the flow rate of the dispersion medium (aqueous phase) was set to 7.5 g / min, and the flow rate of the monomer composition (oil phase) was set to 0.055 g / min.

  In addition, when the droplet (40) which emerges from the through hole (5) is observed through the glass plate (13) of the dispersion medium flow tank (11), the droplet (40) which emerges from the through hole (5) is observed. ) Was smoothly separated from the porous plate (2) and moved downstream without clinging to the surface (3a) in the vicinity of the through hole of the porous plate (2).

  Next, the dispersion medium (41) containing the droplets (40) stored in the generated emulsion storage tank (33) is recovered, and this is heated and polymerized while stirring at 70 ° C. for 6 hours, thereby producing a polymer. Beads were obtained.

<Example 2>
Polymer beads were obtained in the same manner as in Example 1 except that the protrusion height (H) of the protrusion (4) in the perforated plate was set to 20 μm.

<Example 3>
Polymer beads were obtained in the same manner as in Example 1 except that the protrusion height (H) of the protrusion (4) in the perforated plate was set to 28 μm.

<Example 4>
Polymer beads were obtained in the same manner as in Example 1 except that the protrusion height (H) of the protrusion (4) in the perforated plate was set to 5 μm.

<Comparative Example 1>
Polymer beads were obtained in the same manner as in Example 1 except that the protrusion height (H) of the protrusion (4) in the perforated plate was set to 0 μm (the structure without the protrusion). In Comparative Example 1, when the liquid droplets coming out of the through holes were observed, the liquid droplets coming out of the through holes ran around the porous plate to some extent and then separated from the porous plate, or these It was observed that several strips of droplets running on the perforated plate gathered together to form one large strip and then detached.

<Example 5>
The diameter (D) of the through hole (5) is set to 130 μm, the flow rate of the monomer composition (oil phase) is set to 0.050 g / min, and the gap between the porous plate (2) and the glass plate (13) is 1 Polymer beads were obtained in the same manner as in Example 1 except that the thickness was set to 0.0 mm. In addition, when the droplet (40) emerging from the through hole (5) was observed through the glass plate (13), the droplet (40) emerging from the through hole (5) It turned out that it smoothly detach | leaves from the porous plate (2), and does not cling to the surface (3a) etc. of the through-hole vicinity of this.

<Example 6>
Polymer beads were obtained in the same manner as in Example 5 except that the protrusion height (H) of the protrusion (4) in the perforated plate was set to 20 μm.

<Example 7>
Polymer beads were obtained in the same manner as in Example 5 except that the protrusion height (H) of the protrusion (4) in the perforated plate was set to 28 μm.

<Example 8>
Polymer beads were obtained in the same manner as in Example 5, except that the protrusion height (H) of the protrusion (4) in the perforated plate was set to 5 μm.

<Comparative example 2>
Polymer beads were obtained in the same manner as in Example 5 except that the protrusion height (H) of the protrusion (4) in the perforated plate was set to 0 μm (the structure without the protrusion). In Comparative Example 2, when the droplets coming out of the through holes were observed, the droplets coming out of the through holes ran around the porous plate to some extent and then separated from the porous plate, or these It was observed that several strips of droplets running on the perforated plate gathered together to form one large strip and then detached.

<Example 9>
Polymer beads were obtained in the same manner as in Example 1, except that the thickness (W) of the tip edge of the protrusion (4) in the perforated plate was set to 0 μm.

<Example 10>
Polymer beads were obtained in the same manner as in Example 1, except that the thickness (W) of the tip edge of the protrusion (4) in the perforated plate was set to 5 μm.

<Example 11>
Polymer beads were obtained in the same manner as in Example 1 except that the thickness (W) of the tip edge of the protrusion (4) in the perforated plate was set to 30 μm.

<Example 12>
Polymer beads were obtained in the same manner as in Example 1 except that the thickness (W) of the tip edge of the protrusion (4) in the perforated plate was set to 55 μm.

<Example 13>
Polymer beads were obtained in the same manner as in Example 1 except that the thickness (W) of the tip edge of the protrusion (4) in the perforated plate was set to 100 μm.

<Example 14>
Polymer beads were obtained in the same manner as in Example 1 except that the thickness (W) of the tip edge of the protrusion (4) in the perforated plate was set to 130 μm.

<Example 15>
Polymer beads were obtained in the same manner as in Example 5 except that the thickness (W) of the tip edge of the protrusion (4) in the perforated plate was set to 5 μm.

<Example 16>
Polymer beads were obtained in the same manner as in Example 5 except that the thickness (W) of the tip edge of the protrusion (4) in the perforated plate was set to 100 μm.

<Example 17>
Polymer beads were obtained in the same manner as in Example 5 except that the thickness (W) of the tip edge of the protrusion (4) in the perforated plate was set to 200 μm.

<Example 18>
Polymer beads were obtained in the same manner as in Example 5, except that the thickness (W) of the tip edge of the protrusion (4) in the perforated plate was set to 400 μm.

<Example 19>
Polymer beads were obtained in the same manner as in Example 5 except that the thickness (W) of the tip edge of the protrusion (4) in the perforated plate was set to 630 μm.

<Example 20>
Polymer beads were obtained in the same manner as in Example 5 except that the thickness (W) of the tip edge of the protrusion (4) in the perforated plate was set to 800 μm.

  The number average particle diameter and the standard deviation of the particle diameter were determined for each polymer bead obtained as described above. These results are shown in Tables 1-4. The number average particle diameter and the standard deviation of the particle diameter of the polymer beads were measured using an image analysis type particle size distribution measuring apparatus (Mac View Ver. 4.0 manufactured by Mountec Co., Ltd.).

In addition, the standard deviation of a particle size is a value calculated | required by following Formula. That is, it is obtained by the square root of the mean value of the square of the difference between the particle size of the polymer beads and the number average particle size.
Standard deviation = {(1 / n) × Σ n i = 1 (x i -X) 2} 1/2
n: number of polymer beads x _i : particle diameter of polymer beads X: number average particle diameter of polymer beads The number (n) of polymer beads in each example and each comparative example was about 70 to 90 .

  FIG. 8 shows the relationship between the protrusion height (H) of the protrusion and the standard deviation of the particle size of the polymer beads obtained based on the results of Examples 1 to 4 and Comparative Example 1 (Table 1). It is a graph. In Comparative Example 1 in which the projecting portion was not provided on the perforated plate, the standard deviation of the particle size was as large as 55 μm and the variation in the particle size was large. On the other hand, in Examples 1 to 4 in which the protrusions were provided on the porous plate, the standard deviation of the particle size was smaller than that of Comparative Example 1, and the variation in the particle size was small. In particular, in Examples 1 and 2 in which the protrusion height (H) of the protrusion is in the range of 8 to 20 μm, the standard deviation of the particle diameter was about 20 μm or less, and the dispersion of the particle diameter was very small.

  FIG. 9 shows the relationship between the protrusion height (H) of the protrusion and the standard deviation of the particle diameter of the polymer beads obtained based on the results of Examples 5 to 8 and Comparative Example 2 (Table 2). It is a graph. In Comparative Example 2 in which the perforated plate was not provided with a protrusion, the standard deviation of the particle size was as large as 54 μm, and the variation in the particle size was large. On the other hand, in Examples 5 to 8 in which the protrusions were provided on the porous plate, the standard deviation of the particle size was smaller than that of Comparative Example 2, and the variation in the particle size was small. In particular, in Examples 5 and 6 in which the protrusion height (H) of the protrusion is in the range of 8 to 20 μm, the standard deviation of the particle diameter was about 20 μm or less, and the dispersion of the particle diameter was very small.

  FIG. 10 is a graph showing the relationship between the thickness (W) of the tip edge of the protrusion and the standard deviation of the particle size of the resulting polymer beads based on the results of Examples 9 to 14 (Table 3). is there. The protrusion height (H) of the protrusions is 10 μm. From Table 3 and FIG. 10, it can be seen that as the thickness (W) of the tip edge of the protrusion is reduced, the standard deviation of the particle size is reduced and the variation in the particle size is reduced. In particular, in Examples 9 to 13 in which the thickness (W) of the tip edge of the protruding portion is not more than 5 times the diameter of the through hole, the variation in particle diameter was very small. Furthermore, in Examples 9 and 10 in which the thickness (W) of the tip edge of the protrusion is not more than 1 times the diameter (D) of the through hole, the standard deviation of the particle size is 10 μm or less, and the variation in the particle size Was even smaller.

  FIG. 11 is a graph showing the relationship between the thickness (W) of the tip edge of the protrusion and the standard deviation of the particle size of the polymer beads obtained based on the results of Examples 15 to 20 (Table 4). is there. The protrusion height (H) of the protrusions is 10 μm. From Table 4 and FIG. 11, it can be seen that the standard deviation of the particle size is reduced and the variation in the particle size is reduced as the thickness (W) of the tip edge of the protrusion is reduced. In particular, in Examples 15 to 19 in which the thickness (W) of the tip edge of the protrusion is not more than 5 times the diameter of the through hole, the variation in the particle size was very small. Furthermore, in Examples 15 and 16, in which the thickness (W) of the tip edge of the protruding portion is 1 time or less than the diameter (D) of the through hole, the standard deviation of the particle size is 10 μm or less, and the variation in the particle size. Was even smaller.

  The polymer beads produced by the production method of the present invention are used, for example, as an ion exchange resin, a chromatography carrier, a microcapsule or the like.

1 is an overall schematic diagram of a droplet generating apparatus for producing polymer beads according to the present invention. It is the schematic which shows the mixing tank of a droplet production | generation apparatus. It is sectional drawing of the perforated plate used with the droplet production | generation apparatus of FIG. It is sectional drawing which shows other embodiment of a perforated plate. It is sectional drawing which shows other embodiment of a perforated plate. It is a top view of the perforated plate used with the droplet production | generation apparatus of FIG. It is sectional drawing explaining the manufacturing method of a perforated plate, (A) is the resist type | mold produced through the mask exposure / development / cleaning process, (B) is a plate-like metal by electroforming method on the resist type. (C) shows perforated plates obtained by dissolving and removing the resist mold. It is a graph which shows the relationship between the protrusion height H of a protrusion part, and the standard deviation of the particle size of the polymer bead obtained (It is plotted based on the result of Examples 1-4 and Comparative Example 1, Table 1). reference). It is a graph which shows the relationship between the protrusion height H of a protrusion part, and the standard deviation of the particle size of the polymer bead obtained (It is plotted based on the result of Examples 5-8 and Comparative Example 2, Table 2) reference). It is a graph which shows the relationship between the thickness W of the front-end | tip edge of a protrusion part, and the standard deviation of the particle size of the polymer bead obtained (refer to Table 3 plotted based on the result of Examples 9-14). . It is a graph which shows the relationship between the thickness W of the front-end | tip edge of a protrusion part, and the standard deviation of the particle size of the polymer bead obtained (plotted based on the result of Examples 15-20, see Table 4) .

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Droplet production | generation apparatus 2 ... Perforated plate 3 ... Metal plate 3a ... Surface 4 ... Projection part 4a ... Tip edge 5 ... Through-hole 10 ... Mixing tank 11 ... Dispersion medium fluidization tank 12 ... Monomer composition fluidization tank 13 ... Glass plate 40 ... droplet 41 ... dispersion medium (aqueous phase)
42. Monomer composition (oil phase)
D: Diameter of the through hole H: Height of the protrusion W: Thickness of the leading edge of the protrusion

Claims (16)

The one surface side of the porous plate in which a protruding portion that protrudes outward from the surface of the plate extends from the inner peripheral surface of the plate on one surface of the plate provided with a large number of fine through holes. Disposing a dispersion medium on the other surface of the porous plate, disposing the monomer composition on the other side of the porous plate, and ejecting the monomer composition into the dispersion medium on the opposite side through the through holes of the porous plate, Generating droplets of the monomer composition in the dispersion medium;
And a step of polymerizing the monomer composition by applying heat or irradiating light to the dispersion medium containing the droplets to obtain polymer beads.   The method for producing polymer beads according to claim 1, wherein the protruding portion is cylindrical.   The method for producing polymer beads according to claim 1 or 2, wherein the diameter of the through hole is 1 to 300 µm, and the distance from the surface of the perforated plate to the tip edge of the protruding portion is 8 to 20 µm.   The method for producing polymer beads according to claim 1 or 2, wherein the diameter of the through hole is 1 to 300 µm, and the distance from the surface of the perforated plate to the tip edge of the protruding portion is 10 to 15 µm.   The diameter of the said through-hole is 1-300 micrometers, and the thickness of the front-end | tip edge of the said protrusion part is 5 times or less of the diameter of the said through-hole, The manufacture of the polymer bead of any one of Claims 1-4 Method.   The diameter of the said through-hole is 1-300 micrometers, and the thickness of the front-end | tip edge of the said protrusion part is 1 time or less of the diameter of the said through-hole, The manufacture of the polymer bead of any one of Claims 1-4 Method.   The method for producing polymer beads according to any one of claims 1 to 6, wherein a metal plate is used as a plate constituting the porous plate.   The method for producing polymer beads according to any one of claims 1 to 6, wherein a stainless plate, a nickel plate, or a molybdenum plate is used as the plate constituting the porous plate.   The method for producing polymer beads according to any one of claims 1 to 6, wherein the porous plate is a porous nickel plate manufactured by an electroforming method.   The polymer bead manufactured with the manufacturing method of any one of Claims 1-9.   Two plates separated by a perforated plate formed by extending a projecting portion projecting outward from the surface of the plate on one surface of a plate provided with a number of fine through holes from the inner peripheral surface of the through hole. A droplet generator for producing polymer beads, comprising a mixing tank having a tank.   The droplet generating apparatus for producing polymer beads according to claim 11, wherein the diameter of the through hole is 1 to 300 µm, and the distance from the surface of the perforated plate to the leading edge of the protruding portion is 8 to 20 µm.   The droplet generating apparatus for producing polymer beads according to claim 11 or 12, wherein the diameter of the through hole is 1 to 300 µm, and the thickness of the tip edge of the protrusion is not more than 5 times the diameter of the through hole.   The droplet generator for producing polymer beads according to any one of claims 11 to 13, wherein a metal plate is used as a plate constituting the porous plate.   The droplet generating apparatus for producing polymer beads according to any one of claims 11 to 13, wherein a stainless plate, a nickel plate, or a molybdenum plate is used as the plate constituting the porous plate.   The droplet generating apparatus for producing polymer beads according to any one of claims 11 to 13, wherein the porous plate is a porous nickel plate manufactured by an electroforming method.

Images