JP2015174238A - Manufacturing method for molded body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for a molded body that is a molding method using fluid which promotes dispersion of a functional material to thermoplastic resin, which enhances dispersibility of and suppresses aggregation of the functional material in the thermoplastic resin even when using, as the fluid, inactive gas such as pressurized carbon dioxide, water and organic solvent.SOLUTION: The manufacturing method for a molded body includes the steps of: plasticizing thermoplastic resin into molten resin; adjusting pressure of the molten resin to first pressure of 2 MPa-20 MPa; adjusting fluid having second pressure of 4 MPA-30 MPA higher than the first pressure; obtaining a kneaded substance by kneading the molten resin of the first pressure with the fluid with of second pressure; separating the fluid from the molten resin by decreasing gradually the pressure of the kneaded substance two times or more; and molding the molten resin having the fluid separated therefrom into a desired shape. When kneading the fluid with the molten resin, a temperature or pressure of the fluid is set to be less than a critical point.

Description

  The present invention relates to a method for producing a molded body using a fluid.

  Since monodisperse nanoparticles have specific properties such as the development of fluorescence with a narrow half-value width due to the quantum size effect, their synthesis methods and applications have been studied in recent years. Methods for synthesizing monodisperse nanoparticles are roughly divided into vapor phase methods such as CVD (Chemical Vapor Deposition) and liquid phase methods such as sol-gel method and hydrothermal synthesis method. The vapor phase method has the disadvantages of high production costs and difficulty in obtaining monodispersed fine particles. As a liquid phase method, for example, a method disclosed in Patent Document 1 has been reported.

  In Patent Document 1, a metal particle source A, polymer particles B, a substance C that inhibits contact thereof, and a solvent are mixed, and the mixture is subjected to heat treatment and chemical reaction to generate nanoparticle nuclei from the particle source A. Then, a method for producing nanoparticles is disclosed in which heat treatment is performed in a temperature range of 600 ° C. to 1000 ° C. in a region surrounded by polymer particles B.

  Patent Documents 2 to 4 disclose that functional materials such as nanoparticles are mixed with a resin to improve the characteristics of the resin product. For example, in Patent Document 2, in order to disperse highly hydrophilic clay in a thermoplastic resin, the thermoplastic resin is made into a molten resin, and the molten resin, clay, and a solvent containing water or a proton donor are kneaded. Extruding is disclosed. Patent Document 3 discloses that a solid fibrous mesh is obtained by adding a polymer base material, a guest material, high-temperature and high-pressure carbon dioxide to a high-pressure autoclave, and discharging the contents of the high-pressure autoclave through a nozzle to an atmospheric pressure atmosphere. Obtaining a product is disclosed. In a high pressure autoclave, the polymer substrate is plasticized with high temperature, high pressure carbon dioxide and the guest material is incorporated into the polymer substrate, resulting in the guest material being incorporated into the solid fibrous mesh product.

  In Patent Document 4, as a method for obtaining a molded article containing a functional material, the inventors dissolved the functional material in a supercritical fluid such as carbon dioxide, kneaded the carbon dioxide with a molten resin, and then extruded. A molding method for molding is disclosed.

  On the other hand, Patent Document 5 discloses a molding machine that performs injection molding using supercritical carbon dioxide containing a functional material. A sealing mechanism is provided in the plasticizing cylinder of the molding machine to block the flow of molten resin and supercritical carbon dioxide. The sealing mechanism proposed in Patent Document 5 is a sealing mechanism in which a through hole is formed in a screw and a poppet valve that is opened and closed by a spring is disposed in the through hole. Therefore, the molten resin flows through the through holes formed in the screw.

Japanese Patent No. 4767562 JP-A-11-310443 Special Table 2007-509220 Japanese Patent No. 4746708 JP 2011-207160 A

  However, Patent Documents 2 and 3 disclose nothing about a technique for increasing the dispersibility of the functional material in the thermoplastic resin and suppressing aggregation, and a technique for increasing the concentration of the functional material in the thermoplastic resin. Not.

  In Patent Documents 4 and 5, carbon dioxide in a pressurized state is used as a fluid for promoting dispersion of the functional material into the thermoplastic resin, and a method using water, an organic solvent, or the like is disclosed. It has not been. When the methods disclosed in Patent Documents 4 and 5 are carried out using water or an organic solvent in place of carbon dioxide in a pressurized state, the dispersibility of the functional material may be reduced and aggregation may occur.

  Furthermore, the sealing mechanism disclosed in Patent Document 5 has a problem that the structure is complicated and maintenance is difficult. For example, the spring is consumed because it is in contact with the heated molten resin, but is difficult to replace because it is disposed inside the screw. Therefore, when a sealing mechanism is used in a molding machine, a sealing mechanism that is easy to maintain has been demanded.

  The present invention solves these problems, and in a molding method using a fluid that promotes dispersion of a functional material into a thermoplastic resin, an inert gas such as pressurized carbon dioxide is used as the fluid. Not only when water or organic solvents are used, the dispersibility of the functional material in the thermoplastic resin is increased, aggregation is suppressed, and the concentration of the functional material in the thermoplastic resin is increased. Objective.

  According to the present invention, there is provided a method for producing a molded body, wherein a thermoplastic resin is plasticized to be a molten resin, the pressure of the molten resin is adjusted to a first pressure of 2 MPa to 20 MPa, Preparing a fluid having a second pressure higher than 1 and 4 MPa to 30 MPa, and kneading the molten resin at the first pressure and the fluid at the second pressure to obtain a kneaded product. And reducing the pressure of the kneaded material stepwise twice or more to separate the fluid from the molten resin, and forming the molten resin from which the fluid has been separated into a desired shape. A method for producing a shaped article is provided.

  In the present invention, the fluid may contain a functional material.

  In the present invention, the fluid may be at least one selected from the group consisting of an inert gas, water and an organic solvent, and the inert gas may contain nitrogen or carbon dioxide. The fluid may be water, and the organic solvent may be at least one selected from the group consisting of ethanol, isopropyl alcohol, N-methyl-2-pyrrolidone, and hexane. The temperature or pressure of the water or organic solvent may be less than the critical point when the molten resin and the water or organic solvent are kneaded.

  Further, the present invention may include cooling the molten resin and the fluid separated from the molten resin, and collecting the fluid liquefied by being cooled.

  The present invention includes using a molding machine having a plasticizing cylinder, a screw rotatably disposed in the plasticizing cylinder, and a seal mechanism provided in the plasticizing cylinder, In the control cylinder, the kneaded material may be caused to flow downstream of the sealing mechanism in a state where the pressure of the kneaded material upstream of the sealing mechanism is adjusted to the first pressure. Further, in the plasticizing cylinder, with the pressure of the kneaded material upstream of the sealing mechanism adjusted to a third pressure lower than the first pressure, the kneaded material is placed downstream of the sealing mechanism. You may make it flow.

  Further, the kneaded material having a pressure less than a predetermined pressure may not be circulated to the downstream side of the sealing mechanism in the plasticizing cylinder by the sealing mechanism, and the sealing mechanism may be arranged on the outer peripheral surface of the screw via a spring. A seal ring may be included. The flow rate of the kneaded material may be reduced in the plasticizing cylinder by the seal mechanism, and the seal mechanism may be a labyrinth seal. Further, the sealing mechanism may communicate and block the upstream side and the downstream side of the sealing mechanism in the plasticizing cylinder according to the rotational state of the screw, and the sealing mechanism is configured by reverse rotation of the screw. The upstream side and the downstream side of the sealing mechanism are blocked, and the upstream side and the downstream side of the sealing mechanism are separated by either forward rotation of the screw, stoppage of screw rotation, or reduction in the number of reverse rotations of the screw. Further, the plasticizing screw may be repeatedly rotated forward and backward while kneading the molten resin and the fluid.

  The present invention is not limited to the case where an inert gas such as pressurized carbon dioxide is used as a fluid in a molding method using a fluid that promotes dispersion of a functional material into a thermoplastic resin, and water or an organic solvent is used. Even in the case where it is, the dispersibility of the functional material in the thermoplastic resin is increased, aggregation is suppressed, and the concentration of the functional material in the thermoplastic resin is further increased.

It is a flowchart which shows the manufacturing method of the molded object of 1st Embodiment. It is a schematic sectional drawing which shows the molding machine used for 1st Embodiment. FIGS. 3A and 3B are enlarged views of the first downstream seal mechanism of the molding machine used in the first embodiment. It is a schematic sectional drawing which shows the molding machine used for 2nd Embodiment. Fig.5 (a) is an enlarged view of the 1st downstream seal mechanism of the molding machine used for 2nd Embodiment, FIG.5 (b) is the 1st downstream seal mechanism shown to Fig.5 (a). FIG. 5C is a cross-sectional view taken along the line BB ′ of the first downstream seal mechanism shown in FIG. 5A. It is a schematic sectional drawing which shows the molding machine used for 3rd Embodiment. 1 is a schematic view showing a nanoparticle production apparatus used in Example 1. FIG.

[First Embodiment]
The manufacturing method of the molded object of this embodiment is extrusion molding, and can be implemented using the molding machine 1000 shown in FIG. First, the molding machine 1000 will be described.

<Molding machine>
As shown in FIG. 2, the molding machine 1000 is a single-screw extruder. The molding machine 1000 includes a kneading device 200 having a plasticizing cylinder 210, a fluid supply device 100 that supplies a fluid containing a functional material to the plasticizing cylinder 210, and a control device (not shown). The control device controls the operation of the fluid supply device 100 and the kneading device 200. A die 29 is provided at the tip of the kneading apparatus 200, and the molten resin is extruded from the die 29.

  A kneading apparatus 200 shown in FIG. 2 is disposed in the plasticizing cylinder 210, the screw 20 rotatably disposed in the plasticizing cylinder 210, the screw driving mechanism 37 that drives the screw 20, and the plasticizing cylinder 210. And a fluid recovery device 300 connected to the plasticizing cylinder 210. The upstream side sealing mechanism S1 and the first downstream side sealing mechanism S21, the second downstream side sealing mechanism S22, and the plasticizing cylinder 210 are provided. In the present embodiment, in the plasticizing cylinder 210, the plasticized and melted molten resin flows from the right hand to the left hand in FIGS. Therefore, in the plasticizing cylinder 210 of this embodiment, the right hand in FIGS. 2 and 3 is defined as “upstream” or “rear”, and the left hand is defined as “downstream” or “front”. The kneading apparatus 200 of the present embodiment, like the configuration of a conventionally known kneading apparatus, causes the molten resin to move forward (when the screw 20 is rotated counterclockwise when viewed from the rear side of the plasticizing cylinder 210 ( It is configured to perform forward rotation sent to the nozzle part side) and reverse rotation when rotated clockwise.

  A plastic supply port 201 for supplying thermoplastic resin to the plasticizing cylinder 210 and an introduction port 202 for introducing fluid into the plasticizing cylinder 210 are provided on the upper side surface of the plasticizing cylinder 210 in order from the upstream side. Yes. A plurality of discharge ports 203 for discharging fluid from the plasticizing cylinder 210 are formed on the lower side surface of the plasticizing cylinder 210 downstream of the introduction port 202. The resin supply port 201, the introduction port 202, and the discharge port 203 are provided with a resin supply hopper 211, an introduction valve 212, and an extraction pipe 213, respectively. The introduction valve 212 and the extraction pipe 213 are connected to the fluid supply device 100 and the fluid recovery device 300, respectively. A band heater 220 is disposed on the outer wall surface of the plasticizing cylinder 210, whereby the plasticizing cylinder 210 is heated and plasticization of the thermoplastic resin is promoted.

  In the kneading apparatus 200, the thermoplastic resin is supplied from the resin supply port 201 into the plasticizing cylinder 210, and the thermoplastic resin is plasticized by the band heater 220 to become a molten resin. It is done. The molten resin sent to the vicinity of the inlet 202 is contact-kneaded with the introduced fluid under high pressure. Next, by reducing the internal pressure of the molten resin kneaded with the fluid, a part of the gasified fluid is separated from the molten resin and discharged from the discharge port 203. As a result, in the plasticizing cylinder 210, in order from the upstream side, the plasticizing zone 21 that plasticizes the thermoplastic resin into the molten resin, and the molten resin and the fluid introduced from the introduction port 202 are contact-kneaded under high pressure. High-pressure kneading zone 22, decompression zone 23 for reducing the pressure of the molten resin that has been contact-kneaded with the fluid, separation zone 24 for gasifying and separating a part of the fluid from the molten resin, and discharging the separated fluid from the discharge port 203 A discharge zone 25 is formed. A cooling jacket 230 is provided on the outer surface of the plasticizing cylinder 210 where the discharge zone 25 is formed, whereby the molten resin and the fluid separated by gasification are cooled, and the cooled fluid is discharged. It is discharged from the outlet 203. A remelt zone 26 including a band heater 220 is provided downstream of the discharge zone 25. The molten resin cooled in the discharge zone 25 is heated and melted again in the remelt zone 26 and extruded from the die 29.

  The upstream sealing mechanism S1 described above is disposed between the plasticizing zone 21 and the high pressure kneading zone 22, and the first downstream sealing mechanism S21 is disposed between the high pressure kneading zone 22 and the decompression zone 23, The second downstream seal mechanism S22 is disposed between the decompression zone 23 and the separation zone 24. Thus, the decompression zone 23 is defined in the plasticizing cylinder 210 by being sandwiched between the first and second downstream seal mechanisms S21 and S22.

  In this embodiment, the decompression zone 23 is formed from one zone, but the decompression zone 23 may have a plurality of zones. For example, one or more sealing mechanisms can be provided in the decompression zone 23, and the decompression zone 23 can be partitioned into a plurality of zones by the sealing mechanism. In this case, the molten resin flows from the high-pressure kneading zone 22 through the plurality of zones of the decompression zone 23 to the separation zone 24.

  In the kneading apparatus 200 of the present embodiment, the screw 20 has a starvation screw part 20A with a small screw diameter, and the starvation screw part 20A is located in the separation zone 24 of the plasticizing cylinder. The starvation screw unit 20A promotes the decompression of the molten resin and the separation of the fluid from the molten resin in the separation zone 24.

  The fluid supply apparatus 100 according to the present embodiment includes a container 101 in which a fluid (solution or dispersion) C in which a functional material is dissolved or dispersed is contained, pressurization of the fluid C, and liquid feeding to the plasticizing cylinder 210. It consists mainly of two syringe pumps 102 to be performed, an automatic air operated valve 103 for switching between the two syringe pumps 102, and a back pressure valve 104 for controlling the pressure of the fluid C introduced into the plasticizing cylinder 210.

  The fluid recovery device 300 mainly includes a vacuum pump P connected to the extraction pipe 213 and a recovery container 301 connected to the vacuum pump P and recovering the extracted fluid. In the present embodiment, the fluid recovery apparatus 300 also serves as a pressure adjustment mechanism that controls the pressure in the separation zone 24 and the discharge zone 25 to be equal to or lower than atmospheric pressure.

<Seal mechanism>
Next, the upstream side seal mechanism S1, the first downstream side seal mechanism S21, and the second downstream side seal mechanism S22 provided in the molding machine 1000 will be described. As the upstream seal mechanism S1, any seal mechanism can be used as long as the backflow of the resin to the upstream side can be suppressed. For example, a seal ring used for conventional foam molding or the like can be used.

  In the first downstream seal mechanism S21 of the present embodiment, the pressure of the molten resin is adjusted to a first pressure of 2 MPa to 20 MPa in the high-pressure kneading zone 22 on the upstream side of the first downstream seal mechanism S21. A sealing mechanism that can flow the molten resin to the decompression zone 23 on the downstream side of the first downstream sealing mechanism S21 is used. Further, the second downstream seal mechanism S22 of the present embodiment is configured so that the pressure of the molten resin is lower than the first pressure in the decompression zone 23 upstream of the second downstream seal mechanism S22 and A seal mechanism that can flow the molten resin to the separation zone 24 on the downstream side of the second downstream seal mechanism S22 in a state adjusted to a third pressure higher than the fourth pressure is used.

  In the present embodiment, as the first and second downstream side seal mechanisms S21 and S22, seal mechanisms having the same structure including the seal ring 60 provided on the outer peripheral surface of the screw 20 via a spring described below are used. . Since the first and second downstream seal mechanisms S21 and S22 have the same structure, the first downstream seal mechanism S21 will be mainly described below. The first downstream seal mechanism S21 used in the present embodiment is a seal mechanism that prevents the molten resin from flowing from the high-pressure kneading zone 22 to the decompression zone 23 when the pressure in the high-pressure kneading zone 22 is less than a predetermined pressure.

  As shown in FIG. 3, the screw 20 of the present embodiment has a reduced diameter portion 50 that is reduced in diameter in the boundary region between the high-pressure kneading zone 22 and the decompression zone 23 as compared with a region adjacent to the boundary region. ing. The downstream seal ring 60 is externally fitted to the reduced diameter portion 50 so as to be movable in the axial direction (front-rear direction) within the range of the reduced diameter portion 50. The reduced diameter portion 50 and the downstream seal ring 60 constitute a first downstream seal mechanism S21.

  In the screw 20, a downstream screw portion 51 located in the decompression zone 23 is provided adjacent to the downstream side of the reduced diameter portion 50, and the downstream screw portion 51 has a diameter larger than that of the reduced diameter portion 50, and thus the reduced diameter. It has an end surface 51 a continuous with the portion 50. Four holes 51b are formed in the end surface 51a, and a spring piston 61 is disposed in each hole 51b. The spring piston 61 includes a plurality of disc springs 63 disposed in the hole 51b, a ring 64 disposed in contact with the disc spring 63 in the hole 51b, and a part protruding from the hole 51b, A disc spring 63 and a shaft 62 penetrating the ring 64 are formed. As shown in FIG. 3A, the ring 64 of the spring piston 61 is in contact with the downstream seal ring 60, and the downstream seal ring 60 is in the upstream direction (the direction indicated by the arrow in FIG. 3A). Energized. As a result, the inner wall 60a of the seal ring 60 and the outer peripheral surface 50a of the reduced diameter portion 50 come into contact with each other, and communication between the high pressure kneading zone 22 and the decompression zone 23 is blocked.

  Next, the operation of the first downstream seal mechanism S21 will be described. As the screw 20 rotates forward, the molten resin flows from upstream to downstream. As a result, the molten resin staying in the high-pressure kneading zone 22 pushes the downstream seal ring 60 in the downstream direction. However, as shown in FIG. 3 (a), the downstream seal ring 60 is urged in the upstream direction by the spring piston 61, and the communication between the high-pressure kneading zone 22 and the decompression zone 23 is cut off. It cannot flow from the kneading zone 22 to the decompression zone 23.

  Further, when the screw 20 rotates in the forward direction, the molten resin continues to flow from the plasticizing zone 21 to the high pressure kneading zone 22 while the communication between the high pressure kneading zone 22 and the decompression zone 23 is blocked. Pressure increases. When the pressure in the high-pressure kneading zone 22 becomes equal to or higher than a predetermined pressure, the downstream seal ring 60 is pushed by the molten resin in the downstream direction and starts to move. 3B, the inner wall 60a of the downstream seal ring 60 and the outer peripheral surface 50a of the reduced diameter portion 50 are separated from each other, the gap G is opened, and the molten resin is pressurized through the gap G. It becomes possible to move from the kneading zone 22 to the decompression zone 23.

  As shown in FIGS. 2 and 3, the downstream seal ring 60 and the spring piston 61 constituting the first and second downstream seal mechanisms S21 and S22 of this embodiment are circumscribed on the screw 20, and are compared. A simple structure, for example, a complex structure disclosed in Patent Document 5, such as forming a through-hole through which molten resin flows in a screw, and providing a spring piston or a molten resin sealing structure inside the through-hole Is different. As described above, the first and second downstream-side seal mechanisms S21 and S22 of the present embodiment have a simple structure, so that maintenance is easy. In the first and second downstream seal mechanisms S21 and S22, the predetermined pressure at which the gap G starts to open can be adjusted by designing the spring constant of the spring to be used, the number and arrangement of the springs to be used, and the like. . In the present embodiment, the disc spring 63 is used because the stroke is short as the spring, but a coil spring or the like may be used.

<Molding method>
Next, according to the flowchart shown in FIG. 1, the manufacturing method of the molded object of this embodiment is demonstrated. In this embodiment, the molding machine 1000 shown in FIG. 2 described above is used. In the molding machine 1000, the temperatures of the plasticizing zone 21, the high pressure kneading zone 22, the decompression zone 23, the separation zone 24, the discharge zone 25, and the remelting zone 26 of the plasticizing cylinder depend on the type of thermoplastic resin and fluid used. Can be selected as appropriate. In the present embodiment, the screw 20 is rotated in the same direction during the plasticization of the thermoplastic resin and the measurement of the molten resin (during the plasticization measurement) described below.

  First, a thermoplastic resin is supplied to the plasticizing cylinder 210, and the screw 20 is rotated forward to plasticize the thermoplastic resin in the plasticizing zone 21 to obtain a molten resin (step S1).

  As the thermoplastic resin, various resins can be used depending on the type of the target molded article. Specifically, for example, heat of polypropylene, polymethyl methacrylate, polyamide, polycarbonate, amorphous polyolefin, polyether imide, polyethylene terephthalate, polyether ether ketone, ABS resin, polyphenylene sulfide, polyamide imide, polylactic acid, polycaprolactone, etc. Plastic resins and composite materials thereof can be used. In addition, as the thermoplastic resin, those obtained by kneading various inorganic fillers such as glass fiber, talc and carbon fiber may be used, and those obtained by kneading nanofibers such as highly cohesive nanocellulose fiber and carbon nanotube are used. May be. Furthermore, the fibers and fillers kneaded with the thermoplastic resin may be surface-modified with a functional group having a high affinity for fluid. As the thermoplastic resin of this embodiment, one type of resin may be used alone, or two or more types of resins may be mixed and used.

  Next, by rotating the screw 20 forward, the plasticized molten resin is sent from the plasticizing zone 21 to the high-pressure kneading zone 22, and the pressure of the molten resin is set to a first pressure of 2 MPa to 20 MPa in the high-pressure kneading zone 22. (Step S2). When the pressure of the molten resin is increased to 2 MPa to 20 MPa, the kneadability and dispersibility of the molten resin, the fluid, and the functional material are improved. Further, if the first pressure is less than 2 MPa, it is difficult to suppress the pressure loss of the fluid, and if it exceeds 20 MPa, the density of the molten resin becomes too high and the dispersibility of the functional material is lowered. The first pressure is preferably 4 MPa to 15 MPa. Further, the first pressure of the molten resin may vary as long as it is within the above range, but from the viewpoint of the dispersion stability of the functional material, it is preferable to control the variation range within a range of ± 2 MPa, It is more preferable to control within the range of ± 1 MPa.

  In the present embodiment, as described above, the first downstream seal mechanism S21 is provided between the high-pressure kneading zone 22 and the decompression zone 23, and the screw is rotated in the same direction, whereby the pressure of the molten resin is changed to the first pressure. Adjust to pressure. Below, the adjustment method of the pressure of molten resin is demonstrated. First, the screw 20 is rotated forward in a state where the communication between the high-pressure kneading zone 22 and the decompression zone 23 is blocked by the first downstream-side seal mechanism S21. Since the upstream side seal mechanism S1 suppresses the back flow from the high pressure kneading zone 22 to the plasticizing zone 21, the molten resin continues to flow from the plasticizing zone 21 to the high pressure kneading zone 22, and the pressure in the high pressure kneading zone 22 increases. To do. When the pressure of the molten resin in the high-pressure kneading zone 22 further rises to a predetermined pressure or higher by rotating the screw in the forward direction, the high-pressure kneading zone 22 and the pressure-reducing zone 23 communicate with each other by the first downstream seal mechanism S21. The molten resin then flows to the downstream decompression zone 23. When the molten resin flows to the downstream decompression zone 23, the pressure in the high-pressure kneading zone 22 begins to drop, and when the pressure in the high-pressure kneading zone 22 falls below a predetermined pressure, the first downstream seal mechanism S21 again Communication between the high-pressure kneading zone 22 and the decompression zone 23 is blocked. Since the screw rotates in the forward direction, the pressure in the high-pressure kneading zone 22 increases again, and when the pressure exceeds a predetermined pressure, the high-pressure kneading zone 22 and the pressure-reducing zone 23 communicate with each other again by the first downstream seal mechanism S21. The molten resin flows to the downstream decompression zone 23. As described above, in this embodiment, the first downstream seal mechanism S21 is rotated in the same direction (forward rotation) by the screw in the same direction, so that the first downstream seal mechanism S21 has the high-pressure kneading zone 22 and the pressure-reducing zone 23. Repeat communication and disconnection. As a result, the pressure of the molten resin in the high-pressure kneading zone 22 can be maintained at a high pressure (first pressure) with little pressure fluctuation. For example, in Example 1 described later, when the pressure in the high-pressure kneading zone 22 is 6 MPa, the gap G of the first downstream-side seal mechanism S21 begins to open, and the pressure is 10 MPa, as shown in FIG. The first downstream seal mechanism S21 is used in which the seal ring 60 is most advanced in the downstream direction and the gap G is maximized. As a result, in the high-pressure kneading zone 22, the pressure of the molten resin could be adjusted to 10 ± 0.5 MPa.

  Next, a fluid having a second pressure higher than the first pressure and 4 MPa to 30 MPa is prepared (step S3). When the second pressure is less than 4 MPa, the solubility of the fluid in the molten resin decreases, and when the second pressure exceeds 30 MPa, the burden on the device increases and the device cost also increases. The second pressure is preferably 6 MPa to 15 MPa. Further, in order to facilitate the introduction of the fluid into the plasticizing cylinder 210, the second pressure is adjusted to be higher than the first pressure, but the difference between the first pressure and the second pressure is the continuity of the fluid. From the viewpoint of supply stability, 0.1 MPa to 10 MPa is preferable, and 1 MPa to 5 MPa is more preferable.

  In the present invention, the fluid may include a functional material. In this embodiment, the fluid includes a functional material. Hereinafter, the fluid containing the functional material is referred to as “mixed pressurized fluid” as necessary.

  The fluid used in the present embodiment is arbitrary as long as it can serve as a solvent that dissolves the functional material or a dispersion medium that disperses the functional material. For example, an inert gas such as carbon dioxide or nitrogen can be used. These fluids are harmless to the human body, have excellent diffusibility to the molten resin, can be easily removed from the molten resin, and further function as a plasticizer for the molten resin. Moreover, water or an organic solvent can also be used as a fluid. Examples of organic solvents include alcohols such as methanol, ethanol, isopropyl alcohol (IPA), N-methyl-2-pyrrolidone (NMP), hexane, tetrahydrofuran, toluene, N, N-dimethylformamide, acetic acid, ethyl acetate, dimethyl sulfoxide, Various polar and nonpolar organic solvents such as dimethyl ether can be used. As the fluid, ethanol, isopropyl alcohol, N-methyl-2-pyrrolidone and hexane are preferably used. These organic solvent fluids are compatible with carbon dioxide in a supercritical state or a liquid state, and can be mixed with carbon dioxide to increase the permeability to the molten resin. It should be noted that strong acid or strong alkali is preferably not used as a fluid because it may corrode the plasticizing cylinder of the molding machine. As the fluid of this embodiment, one type of fluid may be used alone, or two or more types of fluids may be mixed and used.

  The functional material is not particularly limited as long as it can be dissolved or dispersed in the above-described fluid and can give a predetermined function to the obtained molded body. Examples of such functional materials include inorganic particles such as organometallic complexes, metal alkoxides, and metal particles or precursors thereof; inorganic fillers such as natural minerals, carbon fibers, and glass fibers or modified compounds thereof; carbon nanotubes, nanodiamonds , Nanocarbons such as fullerenes; organic fillers such as cellulose nanofibers, dyes, plasticizers, UV absorbers, heat stabilizers, nucleating agents, antioxidants, catalysts, surfactants, antistatic agents, flame retardant materials, Examples thereof include a compatibilizing agent for promoting alloying of various resins.

  In the present embodiment, all of the functional material is dissolved or dispersed in the fluid and introduced into the molten resin. However, the functional material may be mixed with the thermoplastic resin before contact with the fluid separately from the fluid. When the thermoplastic resin mixed with the functional material is plasticized and melted, for example, the fiber-shaped functional material may be entangled or aggregated. However, when a fluid under pressure is introduced into the molten resin in this state, the fluid under pressure infiltrates into the entangled functional material agglomerates, and the entangled functional material is defibrated to loosen the agglomeration. Can do. According to the method in which the functional material is mixed with the thermoplastic resin before contact with the fluid, the dispersibility of the functional material in the thermoplastic resin can be improved with low shear. For this reason, the cutting | disconnection of the functional material of a filler shape can be suppressed, for example, and the improvement of the rigidity of a molded object can also be anticipated. Examples of the functional material used in the method of mixing the functional material with the thermoplastic resin before contact with the fluid include nanofibers whose surface is chemically modified so as to increase the affinity for the fluid.

  Furthermore, in the present embodiment, nanoparticles having an average particle diameter of 10 nm or less, which are made of metal particles whose surfaces are coated with a water-soluble polymer, can also be used as the functional material. For example, palladium can be used as the metal particles, and examples of the water-soluble polymer include poly (2-vinylpyridine), poly (4-vinylpyridine), polyvinylpyrrolidone, poly (N-vinylacetamide), and poly (vinylamine). Poly (3-vinylpyridine), poly (N-vinylcarbazole), poly (vinylthiazolium salt), polyvinyl alcohol, and the like can be used. Nanoparticles coated with a water-soluble polymer are excellent in dispersibility in a fluid when water is used as the fluid. Further, since the particle size is as small as nano order, for example, when used as a catalyst for electroless plating, high catalytic activity can be exhibited. The metal particles whose surface is coated with a water-soluble polymer can be produced, for example, by the method described in Example 1 described later.

  The concentration of the functional material in the fluid can be appropriately selected in consideration of the type of the functional material to be used and the function of the target molded body, and is not particularly limited. In consideration of the aggregation of the functional material, it is preferably not more than the saturation solubility, and preferably about 1 to 50% of the saturation solubility. In the present embodiment, as described above, the fluid is not limited to the inert gas, and the range of selection is wide. Therefore, the density | concentration of the functional material in a fluid can be raised by employ | adopting the good solvent of a functional material as a fluid.

  It does not specifically limit as a method of preparing a fluid, A conventionally well-known method can be used. In the present embodiment, in the container 101 of the fluid supply apparatus 100 shown in FIG. 2, after the functional material and the fluid are mixed to prepare the fluid C containing the functional material, the pressure is increased by the syringe pump 102, and the back pressure valve 104 is used. A mixed pressurized fluid at a second pressure was prepared.

  The temperature of the mixed pressurized fluid is arbitrary depending on the type of fluid, and can be set to, for example, 10 ° C to 100 ° C. If the temperature is in the range of 10 ° C to 100 ° C, the fluid in the system can be easily controlled. In addition, the fluid pressurized to the second pressure in the present embodiment is preferably in a liquid state, a subcritical state, or a supercritical state because of its high density and stability.

  Next, a fluid containing a functional material adjusted to the second pressure (mixed pressurized fluid) is introduced into the high-pressure kneading zone 22, and the screw 20 is rotated so that the first pressure is increased in the high-pressure kneading zone 22. The molten resin and the fluid having the second pressure are kneaded to obtain a kneaded product (step S4). Dispersibility of the mixed pressurized fluid into the molten resin is improved by mixing the molten resin with the mixed pressurized fluid in a state where the molten resin is pressurized to the first pressure. Any method can be used for supplying the fluid to the high-pressure kneading zone 22. For example, the fluid may be intermittently introduced into the high-pressure kneading zone 22 or may be continuously introduced. In addition, the fluid may be introduced while controlling the introduction amount by using a high-pressure device such as a syringe pump or a double plunger pump capable of stable liquid feeding. In the present embodiment, the mixed pressurized fluid is introduced into the plasticizing cylinder 210 while the introduction amount is controlled by the syringe pump 102 of the fluid supply apparatus 100 shown in FIG.

  Next, the pressure of the molten resin kneaded with the fluid (pressure of the kneaded product) is lowered stepwise twice or more to separate the fluid from the molten resin (steps S5 and S6 in FIG. 1). Thereby, rapid decompression of the molten resin is avoided and aggregation of the functional material can be suppressed. In the present specification, “the pressure of the molten resin kneaded with the fluid” and “the pressure of the molten resin” in the subsequent process of the process of kneading the molten resin and the fluid (the subsequent process of step S4 in FIG. 1) are: It means the “pressure of the kneaded product” of the molten resin and the fluid obtained by the step of kneading the molten resin and the fluid (step S4 in FIG. 1).

  In the present embodiment, the pressure of the molten resin kneaded with the fluid (pressure of the kneaded product) is lowered twice in steps to separate the fluid. First, the pressure of the molten resin (kneaded product pressure) is lowered to a third pressure lower than the first pressure (step S5), and further, a fourth pressure lower than the third pressure and equal to or lower than the atmospheric pressure. The gasified fluid is separated from the molten resin (step S6). In the present embodiment, the fluid can be efficiently separated from the molten resin by reducing the pressure of the molten resin (kneaded product pressure) to the atmospheric pressure or lower (fourth pressure). Also, before the molten resin pressure (kneaded product pressure) is lowered to the fourth pressure, the pressure is once lowered to a third pressure higher than the fourth pressure, thereby avoiding a sudden decompression of the molten resin. , Aggregation of the functional material can be suppressed.

  When the molten resin containing the mixed pressurized fluid is rapidly decompressed, the fluid may be rapidly vaporized and the functional material may be aggregated. In the present embodiment, first, the pressure of the molten resin is lowered to the third pressure, and then lowered to the fourth pressure, so that the pressure of the molten resin is lowered stepwise, thereby the functional material. While maintaining a good dispersion state with the fluid, the decompression of the molten resin proceeds gently. Finally, by reducing the pressure of the molten resin below atmospheric pressure (fourth pressure), the fluid can be separated from the molten resin while maintaining a good dispersion state of the functional material. In particular, when a substance having a low critical point such as water (Tc = 374 ° C.), ethanol (Tc = 240 ° C.), hexane (Tc = 234 ° C.) is used as a fluid, the aggregation of functional materials due to rapid decompression of the molten resin The problem becomes noticeable. Since these substances have a high supercritical temperature, they are not in a supercritical state when kneaded with a molten resin in a plasticizing cylinder. A supercritical fluid has a small change in density due to a change in pressure, whereas a fluid that has not reached the supercritical state has a large change in density due to a change in pressure. For this reason, the density is suddenly lowered and vaporized by a slight pressure change, and the functional material is aggregated. According to the molding method of the present embodiment, a fluid that is not in a supercritical state when kneaded with a thermoplastic resin, i.e., the temperature or pressure of the fluid is less than the critical point, and the density change accompanying the pressure change is large at a high temperature state, Even when a fluid that is difficult to maintain the solvent performance is used, the fluid can be separated from the molten resin while maintaining a good dispersion state of the functional material.

  Further, in this embodiment, before the pressure of the molten resin is lowered to the fourth pressure, a large amount of functional material is made into the molten resin by once lowering it to a third pressure higher than the fourth pressure. Can be mixed. When a large amount of mixed pressurized fluid is introduced into the high-pressure kneading zone 22, the pressure of the high-pressure kneading zone 22 rises before the molten resin and mixed pressurized fluid are sufficiently mixed, and the molten resin reaches the first downstream side. There is a risk of flowing downstream through the side seal mechanism S21. If the molten resin that has passed through the first downstream seal mechanism S21 is suddenly depressurized, the molten resin and the mixed pressurized fluid are not sufficiently mixed, and the functional material together with the fluid or the fluid is also from the molten resin. There is a risk of separation. In the present embodiment, a decompression zone 23 is provided adjacent to the high-pressure kneading sone 22, and before the pressure of the molten resin is lowered to the fourth pressure, the pressure is once lowered to a third pressure higher than the fourth pressure. Thus, rapid decompression of the molten resin can be suppressed. In addition, since the second downstream seal mechanism S22 is provided between the decompression zone 23 and the separation zone 24, the molten resin remains in the decompression zone 23, and the fluid is separated from the molten resin in the separation zone 24. In the decompression zone 23, the molten resin and the mixed pressurized fluid can be sufficiently kneaded before the operation. As a result, in this embodiment, a large amount of mixed pressurized fluid can be mixed with the molten resin, and only the solvent can be separated while maintaining a good dispersion state. Therefore, in order to mix a large amount of the mixed pressurized fluid with the molten resin, it is not necessary to apply a large shearing force to the molten resin, and damage to the resin and the functional material can be reduced. Furthermore, the molding machine used for molding can be an inexpensive single-screw extruder, not a twin-screw extruder or the like.

  The third pressure is arbitrary as long as it is lower than the first pressure and higher than the fourth pressure, but it is preferably 0.1 MPa to 10 MPa, more preferably 1 MPa to 5 MPa. The fourth pressure is arbitrary as long as it is equal to or lower than the atmospheric pressure, but is preferably -0.1 MPa to 0.1 MPa, more preferably -0.05 MPa to 0.1 MPa.

  Next, in this embodiment, a method for adjusting the temperature of the molten resin containing the mixed pressurized fluid to the third pressure and the fourth pressure will be described.

  As described above, in this embodiment, by providing the first downstream-side seal mechanism S21 between the high-pressure kneading zone 22 and the decompression zone 23, the high-pressure kneading zone 22 is maintained at the first pressure, The molten resin flows from the kneading zone 22 to the decompression zone 23 downstream. A second downstream seal mechanism S22 having a structure similar to that of the first downstream seal mechanism S21 is provided between the decompression zone 23 and the separation zone 24, and the pressure is reduced by rotating the screw in the same direction. In the zone 23, the pressure of the molten resin is adjusted to the third pressure. In the present embodiment, by rotating the screw in the same direction (forward rotation), the second downstream seal mechanism S22 communicates and blocks the decompression zone 23 and the separation zone 24 in accordance with the pressure in the decompression zone 23. repeat. As a result, the pressure of the molten resin in the decompression zone 23 can be maintained at a pressure (third pressure) with little pressure fluctuation. For example, in Example 1 to be described later, when the pressure in the decompression zone 23 is 4 MPa, the gap G of the second downstream seal mechanism S22 begins to open, and the pressure is 6 MPa, as shown in FIG. A second downstream side seal mechanism S22 is used in which the ring 60 is most advanced in the downstream direction and the gap G is maximized. As a result, the pressure of the molten resin could be adjusted to 5 ± 0.5 MPa in the high-pressure kneading zone 22.

  The separation zone 24 is adjusted to a fourth pressure below atmospheric pressure. Although the preparation method is arbitrary, for example, the separation zone 24 may be brought to atmospheric pressure by communicating the separation zone 24 with the outside of the plasticizing screw 210, or may be sucked with a vacuum pump or the like to be less than atmospheric pressure. In the present embodiment, a vacuum pump P is connected to the discharge zone 25 adjacent to the downstream side of the separation zone 24, and the separation zone 24 and the discharge zone 25 are depressurized to an atmospheric pressure or lower.

  By rotating the screw 20, the molten resin flows from the decompression zone 23 to the downstream separation zone 24 while maintaining the decompression zone 23 at the third pressure. The molten resin flowing to the separation zone 24 is depressurized to the fourth pressure, and the fluid is gasified and separated from the molten resin. In the present embodiment, the starvation screw portion 20A located in the separation zone 24 promotes the decompression of the molten resin and the separation of the fluid from the molten resin.

  The fluid gasified from the molten resin may be recovered. The fluid separated from the molten resin does not have to be discharged to the outside of the plasticizing cylinder 210 and recovered, but when the fluid is a flammable gas, it is preferable to recover from the safety and environmental aspects. When recovering the fluid, it is preferable that the gasified fluid is cooled and recovered as a liquid from the viewpoint of recovery efficiency.

  In the present embodiment, by rotating the screw 20 forward, the molten resin flows to the discharge zone 25 adjacent to the downstream side of the separation zone 24, and the discharge zone 25 is cooled by the cooling jacket 230, The fluid separated from the molten resin is cooled. Thereby, the molten resin is semi-solidified or solidified, and the fluid separated from the molten resin is liquefied. The liquefied fluid is sucked by the vacuum pump P, passes through the extraction pipe 213, and is collected in the collection container 12. Thus, in this embodiment, since the molten resin is cooled and the molten resin is semi-solidified or solidified, vent-up of the molten resin can be suppressed.

  Next, the molten resin from which the gasified fluid has been separated is formed into a desired shape (step S7). In this embodiment, by rotating the screw 20 forward, the semi-solidified or solidified molten resin flows to the remelting zone 26 adjacent to the downstream side of the discharge zone 25, and the remelting zone 26 is heated by the band heater 220. Thus, the semi-solidified or solidified molten resin was melted. Then, it extrudes from the die | dye 29 and a molded object is obtained.

  In this embodiment, after adjusting the molten resin to the third pressure, the pressure is adjusted to the fourth pressure, but before adjusting to the fourth pressure, the pressure of the molten resin adjusted to the third pressure is adjusted. The pressure may be adjusted once or more to a pressure lower than the third pressure and higher than the fourth pressure. For example, one or more sealing mechanisms are provided in the decompression zone 23, the decompression zone 23 is divided into a plurality of zones by the sealing mechanism, and the molten resin passes through the plurality of zones of the decompression zone 23 from the high-pressure kneading zone 22. And flow to the separation zone 24. And in each zone which decompression zone 23 has, the pressure of molten resin is reduced in steps. Thus, before adjusting to the fourth pressure, the pressure of the molten resin is lowered step by step a plurality of times, thereby allowing a more gentle pressure reduction of the molten resin and further suppressing the aggregation of the functional material. .

[Second Embodiment]
The manufacturing method of the molded object of this embodiment is extrusion molding, and is implemented using the molding machine 2000 shown in FIG. The molding machine 2000 includes first and second downstream seals shown in FIGS. 5A to 5C instead of the first and second downstream seal mechanisms S21 and S22 of the molding machine 1000 shown in FIG. Except for using the mechanisms S31 and S32, the configuration is the same as that of the molding machine 1000 shown in FIG. 2 used in the first embodiment. The first and second downstream seal mechanisms S31 and S32 described below for the first and second downstream seal mechanisms S31 and S32 have the same structure. S31 will be described.

<Seal mechanism>
The first downstream seal mechanism S31 is a high-pressure kneading zone on the upstream side of the first downstream seal mechanism S31, similarly to the first and second downstream seal mechanisms S21 and S22 used in the first embodiment. 22, a sealing mechanism capable of causing the thermoplastic resin to flow into the decompression zone 23 on the downstream side of the first downstream sealing mechanism S31 in a state where the pressure of the molten resin is adjusted to the first pressure of 2 MPa to 20 MPa. is there. In the present embodiment, a labyrinth seal is used as the first downstream seal mechanism S31. The labyrinth seal inhibits the flow of the molten resin due to the shape of the screw flight and reduces the flow rate of the molten resin.

  In the first downstream seal mechanism S31 of the present embodiment, a plurality of screw flights 30, 40 having irregularities along the circumferential direction of the screw 20 are arranged so that the irregularities are alternately arranged in the axial direction of the screw 20. It is constituted by. As shown in FIGS. 5A to 5C, screw flights 30 and 40 are provided on the outer peripheral surface of the screw 20. The screw flights 30 and 40 have a top surface that faces the inner wall of the plasticizing cylinder 210. On the top surface, convex portions 30a and 40a and concave portions 30b and 40b are alternately arranged along the circumferential direction of the screw 20. Is arranged. In the axial direction of the screw 20, the adjacent screw flight 30 and screw flight 40 are arranged so that the unevenness is alternately arranged. That is, the convex portions 30 a and 40 a on the top surface of the screw flights 30 and 40 and the concave portions 30 b and 40 b are alternately arranged along the axial direction of the screw 20. By these screw flights 30 and 40, a labyrinth structure is formed between the inner wall (stationary portion) of the plasticizing cylinder 210 and the screw 20 (rotating shaft) by combining a plurality of uneven gaps. The labyrinth structure that the screw 20 has constitutes the first downstream seal mechanism S31.

  Next, the operation of the first downstream seal mechanism S31 will be described. As the screw 20 rotates forward, the molten resin staying in the high-pressure kneading zone 22 passes through the labyrinth structure of the first downstream-side seal mechanism S31 and tends to flow to the decompression zone 23. The flow of molten resin is hindered by the labyrinth structure, and the flow rate decreases. Since the screw 20 rotates in the forward direction, the pressure in the high-pressure kneading zone 22 increases. Then, the molten resin whose pressure has increased starts to pass through the concave and convex gaps of the labyrinth structure of the first downstream seal mechanism S31. At this time, the molten resin flows to the decompression zone 23 while gradually reducing the pressure while passing through the gaps between the irregularities of the labyrinth structure.

  In this way, the low-pressure molten resin is prevented from flowing from the high-pressure zone 22 to the decompression zone 23 by the first downstream-side seal mechanism S31, and the high-pressure molten resin can pass through the first downstream-side seal mechanism S31. In the present embodiment, the pressure of the molten resin in the high-pressure kneading sone 22 is adjusted to the first pressure of 2 MPa to 20 MPa using this characteristic of the first downstream side seal mechanism S31. In the first downstream seal mechanism S31 of the present embodiment, the pressure value of the high-pressure kneading zone that can be held varies depending on the type of thermoplastic resin and its viscosity, but the pressure of the molten resin in the high-pressure kneading zone 22 is 2 MPa to The labyrinth structure can be designed by a known method so as to be 20 MPa.

  The second downstream seal mechanism S32 is a labyrinth seal having a structure similar to that of the first downstream seal mechanism S31, and the pressure of the molten resin is reduced in the decompression zone 23 upstream of the second downstream seal mechanism S32. The thermoplastic resin can be flowed to the separation zone 24 on the downstream side of the second downstream-side seal mechanism S32 in a state adjusted to a third pressure lower than the first pressure and higher than the fourth pressure. It is a sealing mechanism. Since the first and second downstream seal mechanisms S31 and S32 of the present embodiment are non-contact seal mechanisms that do not have a movable part, maintenance is easy.

<Molding method>
The manufacturing method (extrusion molding) of the molded body of the present embodiment uses a molding machine 2000 having first and second downstream seal mechanisms S31 and S32 shown in FIG. 4 instead of the molding machine 1000 shown in FIG. This can be carried out in the same manner as in the first embodiment, and the same effects can be obtained.

[Third Embodiment]
The manufacturing method of the molded object of this embodiment is extrusion molding, and is implemented using the molding machine 3000 shown in FIG. The molding machine 3000 is the same as that shown in FIG. 2 used in the first embodiment except that the first downstream seal mechanism S41 is used instead of the first downstream seal mechanism S21 of the molding machine 1000 shown in FIG. It is the structure similar to the molding machine 1000 shown. Below, 1st downstream seal mechanism S41 is demonstrated.

<Seal mechanism>
In the present embodiment, a downstream seal mechanism disclosed in International Publication No. 2012/120637 is used as the first downstream seal mechanism S41. The first downstream-side seal mechanism S41 is a seal mechanism that connects and blocks the high-pressure kneading zone 22 and the decompression zone 23 according to the rotational state of the screw 20, and the high-pressure kneading zone 22 by reverse rotation of the screw 20. And the decompression zone 23 are disconnected, and the high pressure kneading zone 22 and the decompression zone 23 are communicated by either forward rotation of the screw 20, stoppage of the rotation of the screw 20, or reduction of the reverse rotation speed of the screw 20. .
<Molding method>
In the injection molding method (extrusion molding) of the present embodiment, a molding machine 3000 shown in FIG. 6 is used instead of the molding machine 1000 shown in FIG. First, by the same method as in the first embodiment, the thermoplastic resin is plasticized in the plasticizing zone 21 to obtain a molten resin (step S1). The plasticized molten resin is sent from the plasticizing zone 21 to the high-pressure kneading zone 22 by rotating the screw 20 forward. At the same time, in the fluid supply device 100, a mixed pressurized fluid having a second pressure higher than the first pressure and 4 MPa to 30 MPa is prepared by the same method as in the first embodiment (step S3). .

  Next, the screw 20 is reversely rotated, and the high pressure kneading zone 22 and the decompression zone 23 are shut off by the first downstream seal mechanism S41. Then, the pressure of the molten resin in the high pressure kneading zone 22 is increased to the first pressure of 2 MPa to 20 MPa by introducing the mixed pressurized fluid at the second pressure into the high pressure kneading zone 22 (step S2).

  Another method for increasing the pressure of the molten resin in the high-pressure kneading zone 22 to the first pressure is to set the clearance through which the resin flows by opening and closing with the driving of the first downstream seal mechanism S41. It is done. Thereby, the flow resistance when the molten resin passes through the first downstream-side seal mechanism S41 during forward rotation can be increased, and the pressure of the molten resin in the high-pressure kneading zone 22 can be increased. Alternatively, the pressure in the high-pressure kneading zone 22 can also be increased by lowering the resin temperature in the high-pressure kneading zone 22 to increase the resin viscosity. These methods are preferable because the pressure of the molten resin in the high-pressure kneading zone 22 can be increased to the first pressure before the pressurized fluid is introduced into the high-pressure kneading zone 22.

  A mixed pressurized fluid at a second pressure is further introduced into the molten resin adjusted to the first pressure and kneaded with the molten resin at the first pressure to obtain a kneaded product (step S4). In the present embodiment, the mixed high pressure fluid and the thermoplastic resin are kneaded by repeating forward and reverse rotations of the screw 20 while introducing the mixed high pressure fluid into the high pressure kneading zone 22 at a constant flow rate. Then, by repeating forward and reverse rotations of the screw 20, the first downstream seal mechanism S 41 repeats communication and blocking between the high-pressure kneading zone 22 and the decompression zone 23. As a result, it is possible to cause the molten resin to flow to the downstream decompression zone 23 while maintaining the pressure of the molten resin (kneaded product pressure) in the high-pressure kneading zone 22 at a high pressure (first pressure) with little pressure fluctuation. . For example, in Example 2 to be described later, the pressure of the molten resin (pressure of the kneaded material) in the high-pressure kneading zone 22 could be adjusted to 9 ± 1 MPa by the first downstream seal mechanism S41.

  Next, the pressure of the molten resin (kneaded product pressure) is lowered to a third pressure lower than the first pressure (step S5). In the present embodiment, as in the first embodiment, the pressure of the molten resin is reduced to the third pressure by providing the second downstream seal mechanism S22 between the decompression zone 23 and the separation zone 24. Can be made. Then, by rotating the screw 20 forward, the molten resin flows from the decompression zone 23 to the downstream separation zone 24 while maintaining the decompression zone 23 at the third pressure.

  Thereafter, by the same method as in the first embodiment, the pressure of the molten resin is lowered to a fourth pressure lower than the third pressure and lower than the atmospheric pressure in the separation zone 24, and gasified from the molten resin. The fluid is separated (step S6), the molten resin is extruded from the die 29, and the molten resin is formed into a desired shape (step S7). The manufacturing method (extrusion molding) of the molded body of this embodiment can produce the same effects as those of the first embodiment.

  The first downstream seal mechanism S41 used in the present embodiment can reliably block the communication between the high-pressure kneading zone 22 and the decompression zone 23 when the screw 20 rotates in reverse, but when the screw 20 rotates forward, Sudden decompression of the upstream zone (high pressure kneading zone 22) is likely to occur due to the influence of the pressure of the downstream zone (decompression zone 23). In the present embodiment, a second downstream seal mechanism S22 that controls the flow of the molten resin is provided downstream of the first downstream seal mechanism S41 regardless of the screw rotation direction, and the pressure in the decompression zone 23 is increased. The third pressure is maintained. For this reason, even when the screw 20 is rotating forward, sudden pressure reduction in the high-pressure kneading zone 22 can be suppressed.

  As described above, in the first to third embodiments, the seal mechanism including the seal ring provided on the outer peripheral surface of the screw 20 via the spring (the first and second downstream seal mechanisms S21 and S22 of the first embodiment). ), A labyrinth seal mechanism (first and second downstream seal mechanisms S31 and S32 of the second embodiment), and a seal mechanism that communicates and blocks the zones according to the rotational state of the screw 20 (third embodiment). Although the first downstream seal mechanism S41) of the present invention has been described, the seal mechanism used for carrying out the present invention is not limited to these, and these seal mechanisms are optional in one plasticizing cylinder. These may be used in combination. However, the seal mechanism installed between the separation zone 24 and the decompression zone 23 is a seal mechanism (for example, the first downstream seal of the third embodiment) that communicates and blocks between the zones according to the rotational state of the screw 20. Seal mechanism (for example, first and second downstream seal mechanisms S21, S22, and second implementation of the first embodiment) that flows and blocks between zones not by the mechanism S41) but by the pressure of the molten resin upstream. It is preferable to use the first and second downstream seal mechanisms S31, S32) of the form. The seal mechanism that communicates and blocks between the zones according to the rotational state of the screw 20 may cause the upstream zone (decompression zone) to suddenly depressurize when the separation zone 24 and the decompression zone 23 communicate with each other. This is because a large pressure fluctuation may occur.

  EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not limited to these Examples.

[Example 1]
In this example, using a molding machine 1000 shown in FIG. 2, a string-like molded body was extruded and cut to produce resin pellets. Furthermore, a molded body was injection molded using the obtained resin pellets.

  Nylon 6 (manufactured by Toyobo, Gramide T777-02) was used as the thermoplastic resin, and water was used as the fluid. As the functional material, palladium (Pd) nanoparticles coated with a water-soluble polymer that function as a catalyst for electroless plating were used. In this embodiment, the extrusion discharge amount of the molten resin is 10 kg / h, the fluid (water) is introduced into the molten resin by 100% by weight, and the functional material (nanoparticles) is contained in the molten resin by 3% by weight. I let you.

    First, the apparatus and manufacturing method used for the production of nanoparticles, which are functional materials used in this example, will be described.

<Nanoparticle production equipment>
Nanoparticles were produced using the device 4000 shown in FIG. In this example, polyvinyl pyrrolidone (ISP, PVP K-120, molecular weight 640,000) was used as the water-soluble polymer, and the first solution was prepared using ethanol as the alcohol (first solvent). A second solution was prepared using hexafluoroacetylacetonato palladium (II) which is a palladium complex as a precursor, and n-hexane as a poor solvent (second solvent) of the water-soluble polymer.

  The nanoparticle production apparatus 4000 used in this example will be described. As shown in FIG. 7, the nanoparticle manufacturing apparatus 4000 includes a first solution supply mechanism 700, a second solution supply mechanism 800, a nanoparticle synthesis unit 900, and a nanoparticle recovery unit 950.

  The first and second solution supply mechanisms 700 and 800 are connected to the nanoparticle synthesis unit 900 via check valves 77 and 87, and supply the first solution and the second solution to the nanoparticle synthesis unit 900, respectively. To do. The first solution supply mechanism 700 includes a first solution supply container 70 in which a first solution is prepared, and the first solution is sucked from the first solution supply container 70, then the pressure is increased to a predetermined pressure, and the liquid is supplied at a constant flow rate. It consists of two possible syringe pumps 71 and 72, two suction air automatic valves 73 and 74 arranged in the pipe, and two liquid feed air automatic valves 75 and 76. The second solution supply mechanism 800 has the same configuration as that of the first solution supply mechanism 700, and the second solution supply container 80 in which the second solution is prepared, and after the second solution is sucked from the second solution supply container 80, It consists of two syringe pumps 81 and 82 that increase the pressure to a predetermined pressure, two suction air automatic valves 83 and 84 arranged in the pipe, and two liquid feed air automatic valves 85 and 86. Since the first and second solution supply mechanisms 700 and 800 have syringe pumps 71, 72, 81, and 82 capable of flow rate control and pressure control, the first and second solutions with the flow rate and pressure controlled to a predetermined amount are supplied. It can be sent to the nanoparticle synthesis unit 900. The syringe pumps 71, 72, 81, 82 open the suction air automatic valves 73, 74, 83, 84 to suck the solution into the syringe pump, then close the valves and pressurize them to maintain a predetermined pressure. . When liquid is fed, the liquid automatic air valves 75, 76, 85, and 86 are opened, and liquid can be fed at a constant flow rate by pushing the syringe of the syringe pump at a constant speed. The pressure at the time of flowing the pressurized fluid by the flow rate control is adjusted by the back pressure valve 99 at the end of the path. In each of the first and second solution supply mechanisms 700 and 800, when one pump (for example, syringe pumps 71 and 81) is feeding liquid, the other pump (syringe pumps 72 and 82) sucks and adds the solution. Press and wait. At the timing when the pressurized solution in one pump (syringe pumps 71, 81) that is feeding liquid becomes empty, the pump is switched, and this time, the other pump (syringe pumps 72, 82) feeds the liquid. Start. Accordingly, the first and second solutions can be supplied (supplied) from the first and second solution supply mechanisms 700 and 800 to the nanoparticle synthesis unit 900 with the pressure and the flow rate kept constant. The particle manufacturing apparatus 4000 can continuously manufacture nanoparticles. The second solution supply container 80 is a high-pressure sealed container so as to accommodate a high-pressure fluid such as pressurized carbon dioxide.

The nanoparticle synthesis unit 900 is connected to the first and second solution supply mechanisms 700 and 800 as described above, and is also connected to the nanoparticle recovery unit 950 via the pressure gauge 98 and the back pressure valve 99. The nanoparticle synthesis unit 900 prepares a mixed solution by mixing the first solution and the second solution supplied from the first and second solution supply mechanisms 700 and 800, and then synthesizes nanoparticles in the mixed solution. Then, the mixed solution containing the synthesized nanoparticles is sent to the nanoparticle recovery unit 950. The nanoparticle synthesis unit 900 includes a cylindrical electric furnace 90 having a pipe 91 spirally formed on the inner wall, and the inlet 90a side of the cylindrical electric furnace 90, that is, the first and second solution supply mechanisms 700 and 800. The cooling double pipe 92 arranged on the side, and the cooling double pipe 93 arranged on the outlet 90b side of the cylindrical electric furnace 90, that is, on the nanoparticle recovery unit 950 side. The first and second solutions supplied from the first and second solution supply mechanisms 700 and 800 are joined and mixed at the joining point 94 to form a mixed solution, and then the cooling double pipe 92 and the electric furnace 90 are provided. It flows through the spiral pipe 91 and the cooling double pipe 93 and is sent to the nanoparticle recovery unit 950. In the nanoparticle production apparatus 4000, a thickness of 0.5 mm (0.02) is provided in all pipes (tubes) through which the mixed solution including the pipe 91 in the electric furnace 90 and the double pipes 92 and 93 for cooling flow. Inch) and an outer diameter of 1.58 mm (1/16 inch) SUS316 piping. The length of the pipe 91 in the electric furnace 90 was about 2 m, and the internal volume of the pipe 91, that is, the volume of the nanoparticle synthesis reaction field was about 0.51 cm ³ .

  The nanoparticle recovery unit 950 includes a cyclone 95 that separates gas and liquid by centrifugation, and a recovery container 96 that recovers the solution from which the gas has been separated. When a high pressure vessel such as pressurized carbon dioxide is used as the second solvent (poor solvent for the water-soluble polymer), the second solvent is removed from the mixed solution by the cyclone 95. In this example, since pressurized carbon dioxide was not used as the second solvent, the cyclone 95 was not used, and the mixed solution containing the synthesized nanoparticles was directly recovered in the recovery container 96.

<Manufacture of nanoparticles>
In the 1st solution supply container 70, polyvinylpyrrolidone which is water-soluble polymer was melt | dissolved in ethanol which is a 1st solvent, and the 1st solution was prepared. The polyvinyl pyrrolidone concentration in the first solution was 3 g / L. In the 2nd solution supply container 80, the palladium complex was melt | dissolved as a precursor of a metal particle in n-hexane which is a 2nd solvent, and the 2nd solution was prepared. The palladium complex concentration in the second solution was 800 mg / L. At this time, the color of the second solution was yellow resulting from the palladium complex.

  Next, in the first solution supply mechanism 700, the suction air automatic valve 73 was opened, the first solution was sucked into the syringe pump 71, and the pressure was increased to 20 MPa. Similarly, in the second solution supply mechanism 800, the suction air automatic valve 83 was opened, the second solution was sucked into the syringe pump 81, and the pressure was increased to 20 MPa. At this time, the temperature in the syringe pumps 71 and 81 was normal temperature (25 ° C.).

  Next, the liquid automatic air valves 75 and 85 were opened, and both the first and second solutions were fed to the nanoparticle synthesis unit 900. The first and second solutions passed through check valves 77 and 87, merged at a junction 94, and mixed to form a mixed solution having a pressure of 10 MPa. The syringe pumps 71 and 81 are controlled so that the first solution and the second solution are mixed at a volume ratio of 1: 1, and further, the cooling double pipe 92, the pipe 91 in the electric furnace 90, and the cooling double pipe Through 93, the back pressure valve 99 was filled with a mixed solution having a pressure of 10 MPa. At this time, the temperature of the electric furnace 90 is controlled to 200 ° C., 20 ° C. cooling water is passed through the cooling double pipes 92 and 93, and the back pressure valve 99 displays the pressure gauge 98 as 10 MPa in advance. Controlled to be.

  Next, the syringe pumps 71 and 81 were switched to flow control, and the mixed solution was circulated in the pipe at a flow rate of 1 ml / min. One minute after starting the flow control of the syringe pumps 71 and 81, the mixed solution was dropped into the collection container 96 as a black liquid from the lower part of the cyclone 95. From the color of the collected mixed solution, it is presumed that the palladium complex of the raw material was decomposed and reduced to become palladium.

  Ethanol (first solvent) and n-hexane (second solvent) were removed from the mixed solution (black solution) collected in this example by an evaporator to obtain a black powder.

  The obtained nanoparticles were put into water and the dispersibility in water was evaluated. The nanoparticles showed good dispersibility in water without settling. From this result, it is surmised that the obtained nanoparticles have a core-shell structure coated with a water-soluble polymer.

  On the other hand, as a result of TEM observation, the average particle diameter of the nanoparticles obtained in this example was 10 nm. The average particle diameter of the nanoparticles is a value obtained by observing the nanoparticles with a TEM and measuring the particle diameters of 50 to 100 particles and averaging them.

<Production method of resin pellet>
In this embodiment, a water tank and a strand cutting device (not shown) are arranged in this order at the tip of the die 29 of the molding machine 1000 shown in FIG. A general purpose thing was used for the water tank and the strand cut device. Thereby, the molded product extruded from the die 29 in a string shape was cooled in a water tank, and cut with a strand cutting device to continuously produce resin pellets.

  First, in the container 101 of the fluid supply apparatus 100, the produced nanoparticles were dispersed in water to prepare a dispersion C. The concentration of nanoparticles in the dispersion was 3% by weight. Dispersion C was suctioned and pressurized by syringe pump 102 (ISCO, 500D), and then syringe pump 102 was switched to flow control and fed to plasticizing cylinder 210. In the dispersion C, the pressure was controlled to 13 MPa by the back pressure valve 104 (hereinafter, the pressurized dispersion C is referred to as “mixed pressurized fluid” as necessary). As a result, the system up to the introduction valve 212 for introducing the fluid into the plasticizing cylinder 210 was pressurized with the mixed pressurized fluid. The two syringe pumps 102 were switched by opening and closing the automatic air operated valve 103 by a control device (not shown).

  Next, in the kneading apparatus 200, the thermoplastic resin is supplied from the resin supply hopper 211, the plasticizing zone 21 is heated by the band heater 220 provided on the outer wall surface of the plasticizing zone 21, and the screw 20 is rotated forward. It was. Thus, the thermoplastic resin was heated and kneaded to obtain a molten resin. In this example, the plasticizing zone 21 of the plasticizing cylinder 210 was heated so that the temperature of the molten resin was 210 to 240 ° C. In this embodiment, in order to facilitate separation of the molten resin and the fluid in the subsequent process, a general-purpose feeder screw (not shown) is used to limit the amount of thermoplastic resin supplied to the plasticizing cylinder 200. I put it in. Further, in this example, the screw 20 was rotated in the same direction (forward rotation) until the measurement of the molten resin was completed thereafter.

  By rotating the screw 20 forward, the molten resin was caused to flow from the plasticizing zone 21 to the high-pressure kneading zone 22. As described above, when the pressure in the high pressure kneading zone 22 is 6 MPa, the first downstream seal mechanism S21 starts to open the gap G of the first downstream seal mechanism S21, and the pressure is 10 MPa. As shown in b), the seal ring 60 is most advanced in the downstream direction, and the gap G is maximized. In this example, the pressure of the resin in the high-pressure kneading zone 11 was controlled to be stable at 10 ± 0.5 MPa (first pressure) by using the first downstream-side seal mechanism S21.

  Next, the introduction valve 212 was opened, and the mixed pressurized fluid was introduced into the high-pressure kneading zone 22 at a constant flow rate by the syringe pump 102. Then, the screw 20 is rotated forward, and in the high-pressure kneading zone 22, the mixed pressurized fluid of 13 MPa (second pressure) is kneaded into the molten resin adjusted to 10 ± 0.5 MPa (first pressure), A kneaded product was obtained. The pressure inside the plasticizing cylinder 210 monitored by a pressure sensor (not shown) provided immediately below the main introduction valve 212 was stable at 10 ± 0.5 MPa MPa even after the introduction of the fluid.

  By using the first downstream seal mechanism S21 and rotating the screw 20 forward, the molten resin flows into the decompression zone 23 while the high-pressure kneading zone 22 is maintained at 10 ± 0.5 MPa (first pressure). I let you. Then, the pressure of the molten resin in the decompression zone 23 was adjusted to 5 ± 0.5 MPa (third pressure) by rotating the screw in the same direction using the second downstream seal mechanism S22. As described above, when the pressure in the decompression kneading zone 23 is 4 MPa, the second downstream seal mechanism S22 starts to open the gap G of the second downstream seal mechanism S22, and the pressure is 6 MPa. As shown in b), the seal ring 60 is most advanced in the downstream direction, and the gap G is maximized.

  In the separation zone 24, the vacuum pump P provided in the discharge zone 25 was driven, and the pressure in the separation zone 24 was adjusted to -0.01 MPa (fourth pressure) together with the pressure in the discharge zone 25. Then, by rotating the screw 20, the molten resin was caused to flow from the decompression zone 23 to the downstream separation zone 24 while maintaining the decompression zone 23 at 5 ± 0.5 MPa (third pressure). The molten resin that flowed to the separation zone 24 was decompressed to −0.01 MPa (fourth pressure), and water (fluid) was gasified and separated from the molten resin. In the present embodiment, the starvation screw portion 20A located in the separation zone 24 promotes the decompression of the molten resin and the separation of the fluid from the molten resin.

  The molten resin was caused to flow from the separation zone 24 to the discharge zone 25 by rotating the screw 20. In the discharge zone 25, the discharge zone 25 was cooled by the cooling jacket 230. Thereby, the molten resin was semi-solidified or solidified, and the water (fluid) separated from the molten resin was liquefied. The liquefied water (fluid) was sucked by the vacuum pump P, passed through the extraction pipe 213, and collected in the collection container 12.

  By rotating the screw 20, the molten resin from which the gasified water (fluid) was separated was further flowed to the downstream remelting zone 26. In the remelting zone 26, the semi-solidified or solidified molten resin was again heated and melted by the band heater 220. Thereafter, the screw 20 was rotated to extrude the molten resin from the die 29 in a string shape.

  The obtained string-like extrudate was passed through a water tank (not shown), and then continuously cut with a strand cutting device (not shown) to produce resin pellets. The obtained resin pellet was visually observed. The resin pellets were not observed to have any adverse effects of cloudiness or hydrolysis. From this, it was speculated that the moisture used as a fluid did not remain in the obtained resin pellets so as to adversely affect the function of the resin pellets.

<Molding of molded body>
A general-purpose injection molding machine (manufactured by Nippon Steel Works, J180AD-2M) was used, and a flat molded body was molded using the produced resin pellets. The obtained molded body was visually observed. As a result, an aggregate of palladium nanoparticles (functional material) could not be confirmed. The cross section of the obtained molded body was observed with a TEM (transmission electron microscope). As a result, it was confirmed that the palladium particles were uniformly dispersed in the molded body while maintaining an average particle diameter of about 10 nm. As described above, in this example, the palladium nanoparticles (functional material) could be contained in a large amount of 3% by weight without agglomeration.

[Example 2]
In this example, resin pellets were produced from the same material as in Example 1 using the molding machine 3000 shown in FIG. 6, and further molded by the same method as in Example 1 using the obtained resin pellets. The body was injection molded.

<Pellet manufacturing method>
First, in the same manner as in Example 1, the thermoplastic resin was plasticized in the plasticizing zone 21 to obtain a molten resin, and the plasticized molten resin was flowed from the plasticizing zone 21 to the high-pressure kneading zone 22. In parallel with this, in the fluid supply apparatus 100, a mixed pressurized fluid of 13 MPa (second pressure) was prepared by the same method as in Example 1.

  Next, the screw 20 was reversely rotated, the high pressure kneading zone 22 and the decompression zone 23 were shut off by the first downstream side seal mechanism S41, and the mixed pressurized fluid was introduced into the high pressure kneading zone 22. The pressure in the high-pressure kneading zone 22 reached a maximum of 9 ± 1 MPa after the introduction of the fluid. Subsequently, while the mixed high-pressure fluid was introduced into the high-pressure kneading zone 22 at a constant flow rate, the forward rotation and the reverse rotation of the screw 20 were repeated. As a result, the first downstream seal mechanism S41 repeatedly communicated and blocked the high-pressure kneading zone 22 and the decompression zone 23. As a result, in the high-pressure kneading zone 22, the molten resin can be flowed to the decompression zone 23 while kneading with the mixed high-pressure fluid in a state where the pressure of the molten resin is adjusted to 9 ± 1 MPa (first pressure). It was. As in the first embodiment, the second downstream seal mechanism S22 is used and the screw is rotated in the same direction, whereby the pressure of the molten resin in the decompression zone 23 is 5 ± 0.5 MPa (third pressure). Adjusted.

  In the same manner as in Example 1, the pressure in the separation zone 24 was adjusted to −0.01 MPa (fourth pressure), and the pressure was reduced while the pressure reduction zone 23 was maintained at 5 ± 0.5 MPa (third pressure). The molten resin was caused to flow from the zone 23 to the downstream separation zone 24. The molten resin that flowed to the separation zone 24 was decompressed to -0.01 MPa (fourth pressure), and water (fluid) was gasified and separated from the molten resin.

  In the same manner as in Example 1, the molten resin is flowed from the separation zone 24 to the discharge zone 25, and the water (fluid) separated from the molten resin is recovered in the recovery container 12, and further flows to the downstream remelt zone 26. Then, it was extruded from the die 29 in a string shape. The obtained string-like extrudate was cooled by the same method as in Example 1 and then cut to obtain resin pellets. The obtained resin pellet was visually observed. The resin pellets were not observed to have any adverse effects of cloudiness or hydrolysis. From this, it was speculated that the moisture used as a fluid did not remain in the obtained resin pellets so as to adversely affect the function of the resin pellets.

<Molding of molded body>
As in Example 1, a general-purpose injection molding machine was used, and a flat molded body was molded using the produced resin pellets. The obtained molded body was visually observed. As a result, an aggregate of palladium nanoparticles (functional material) could not be confirmed. The cross section of the obtained molded body was observed with a TEM (transmission electron microscope). As a result, it was confirmed that the palladium particles were uniformly dispersed in the molded body while maintaining an average particle diameter of about 10 nm. As described above, in this example, the palladium nanoparticles (functional material) could be contained in a large amount of 3% by weight without agglomeration.

[Comparative Example 1]
In this comparative example, a molding machine having the same structure as the molding machine 3000 shown in FIG. 6 used in Example 2 is used, except that the second downstream seal mechanism S22 is not provided. Resin pellets were prepared from the above materials, and a molded body was injection molded by the same method as in Example 1 using the obtained resin pellets. Since the molding machine used in this comparative example is not provided with the second downstream seal mechanism S22, the decompression zone 23 does not exist, and the high-pressure kneading zone 22 and the separation zone 24 are adjacent to each other.

<Pellet manufacturing method>
In this comparative example, as in Example 2, while the mixed high-pressure fluid was introduced into the high-pressure kneading zone 22 at a constant flow rate, the forward rotation and the reverse rotation of the screw 20 were repeated. When the zone 22 and the separation zone 24 were communicated, the pressure in the high-pressure kneading zone 22 fluctuated greatly from 0 to 6 MPa. That is, in this comparative example, the mixed pressurized fluid could not be kneaded with the molten resin adjusted to the first pressure of 2 MPa to 20 MPa. Further, in this comparative example, since a molding machine that does not have the decompression zone 23 adjusted to the third pressure is used, before the pressure of the molten resin is lowered to the fourth pressure (separation zone 24), the first It was not possible to adjust to a third pressure lower than the pressure and higher than the fourth pressure. Except for the matters described above, resin pellets were produced in the same manner as in Example 2.

<Molding of molded body>
As in Example 1, a general-purpose injection molding machine was used, and a flat molded body was molded using the produced resin pellets. The obtained molded body was visually observed. As a result, an aggregate of palladium nanoparticles (functional material) having a size that can be visually confirmed was confirmed. This is presumably due to the following reasons. In this comparative example, the pressure fluctuation in the high-pressure kneading zone 22 is large, the density of the fluid functioning as a solvent is lowered, and a good dispersion state of the functional material cannot be maintained. Therefore, the mixed pressurized fluid cannot be kneaded with the molten resin adjusted to the first pressure, and it is considered that the kneadability and dispersibility of the palladium nanoparticles (functional material) in the molten resin are reduced. In addition, it was considered that the aggregation of the palladium nanoparticles (functional material) was promoted because the stepped reduction to the third pressure was not performed before the molten resin was reduced to the fourth pressure.

[Comparative Example 2]
In this comparative example, resin pellets were produced from the same materials as in Example 1 using the molding machine 1000 shown in FIG. 2 used in Example 1, and further, the resin pellets obtained were used in Example 1. The molded body was injection molded by the same method as described above. However, in this comparative example, the vacuum pump P was not driven and the separation zone 24 was not cooled by the cooling jacket 230 in the production of the resin pellets.

<Pellet manufacturing method>
In this comparative example, since the vacuum pump P was not driven, the separation zone 24 was not adjusted to the fourth pressure below atmospheric pressure, and the molten resin that flowed to the separation zone 24 was not adjusted to the fourth pressure. Also, water (fluid) was not recovered in the recovery container 12. Except for the matters described above, resin pellets were produced in the same manner as in Example 1. The obtained resin pellet was visually observed. White turbidity was confirmed in the resin pellet. From this, it is estimated that the obtained resin pellets are not completely separated from moisture (functional material). This is presumably because the molten resin was not depressurized to the fourth pressure, so that the water (fluid) was not sufficiently separated from the molten resin.

<Molding of molded body>
For the purpose of removing moisture, the obtained resin pellets were dried at 80 ° C. for 8 hours. Thereafter, in the same manner as in Example 1, a general-purpose injection molding machine was used to mold a flat molded body using the produced resin pellets. The obtained molded body was visually observed. As a result, silver streaks (silver marks) were generated in the obtained molded body. From this, it was found that moisture remained in the obtained molded body.

  According to the present invention, in a molding method using a fluid that promotes dispersion of a functional material into a thermoplastic resin, the range of fluid selection is widened. Thereby, it becomes possible to manufacture efficiently the molded object containing various functional materials.

20 Screw S1 Upstream side sealing mechanism 100 Fluid supply device 200 Kneading device 210 Plasticizing cylinder 1000, 2000, 3000 Molding machines S21, S31, S41 First downstream side sealing mechanism S22, S32 Second downstream side sealing mechanism

Claims (17)

A method for producing a molded body, comprising:
Plasticizing the thermoplastic resin into a molten resin;
Adjusting the pressure of the molten resin to a first pressure of 2 MPa to 20 MPa;
Preparing a fluid at a second pressure higher than the first pressure and between 4 MPa and 30 MPa;
Kneading the molten resin at a first pressure and the fluid at a second pressure to obtain a kneaded product;
Separating the fluid from the molten resin by stepwise reducing the pressure of the kneaded product two or more times;
A method for producing a molded body comprising molding the molten resin from which the fluid has been separated into a desired shape.   The method for producing a molded body according to claim 1, wherein the fluid contains a functional material.   The method for producing a molded body according to claim 1 or 2, wherein the fluid is at least one selected from the group consisting of an inert gas, water, and an organic solvent.   The said fluid is the said inert gas, The said inert gas contains nitrogen or a carbon dioxide, The manufacturing method of the molded object of Claim 3 characterized by the above-mentioned.   The said fluid is water, The manufacturing method of the molded object of Claim 3 characterized by the above-mentioned.   4. The fluid is the organic solvent, and the organic solvent is at least one selected from the group consisting of ethanol, isopropyl alcohol, N-methyl-2-pyrrolidone, and hexane. The manufacturing method of the molded object of description.   The method for producing a molded body according to claim 5 or 6, wherein when the molten resin and the fluid are kneaded, the temperature or pressure of the fluid is less than a critical point. Furthermore,
Cooling the molten resin and the fluid separated from the molten resin;
The method for producing a molded body according to claim 1, further comprising recovering the fluid liquefied by being cooled. Using a molding machine having a plasticizing cylinder, a screw rotatably disposed in the plasticizing cylinder, and a seal mechanism provided in the plasticizing cylinder,
The kneaded material is caused to flow downstream of the sealing mechanism in a state where the pressure of the kneaded material upstream of the sealing mechanism is adjusted to a first pressure in the plasticizing cylinder. The manufacturing method of the molded object as described in any one of 1-8. Using a molding machine having a plasticizing cylinder, a screw rotatably disposed in the plasticizing cylinder, and a seal mechanism provided in the plasticizing cylinder,
In the plasticizing cylinder, with the pressure of the kneaded material upstream of the sealing mechanism adjusted to a third pressure lower than the first pressure, the kneaded material is caused to flow downstream of the sealing mechanism. The manufacturing method of the molded object as described in any one of Claims 1-8 characterized by the above-mentioned.   The method for manufacturing a molded body according to claim 9 or 10, wherein the sealing mechanism prevents a kneaded material having a pressure less than a predetermined pressure from flowing downstream of the sealing mechanism in the plasticizing cylinder.   The said sealing mechanism contains the seal ring provided in the outer peripheral surface of the said screw via a spring, The manufacturing method of the molded object of Claim 11 characterized by the above-mentioned.   The method for producing a molded body according to claim 9 or 10, wherein the flow rate of the kneaded material is reduced in the plasticizing cylinder by the sealing mechanism.   The method for manufacturing a molded body according to claim 13, wherein the seal mechanism is a labyrinth seal.   The said sealing mechanism communicates and interrupts | blocks the upstream and downstream of the said sealing mechanism in the said plasticization cylinder according to the rotation state of a screw, The manufacturing of the molded object of Claim 9 or 10 characterized by the above-mentioned. Method.   The seal mechanism shuts off the upstream side and the downstream side of the seal mechanism by reverse rotation of the screw, and either by forward rotation of the screw, stop of rotation of the screw, or reduction of the rotational speed of reverse rotation of the screw, The method for producing a molded body according to claim 15, wherein the upstream side and the downstream side of the sealing mechanism are communicated with each other. The method for producing a molded body according to claim 16, wherein the plasticizing screw is repeatedly rotated forward and reverse while kneading the molten resin and the fluid.

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