JP2009116326A - Carrier and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a carrier as a constituent raw material of a two-component developer, which makes organic solvent unnecessary, does not require high energy, can freely control film thickness, moreover, can form thick coated film, does not cause aggregation among particles and has homogeneous film composition, with respect to the carrier as a constituent raw material of the two-component developer in color toner used for a dry developing system as a printing method of electrophotography or the like and to provide the manufacturing method of the carrier; and to provide a method of manufacturing the carrier. <P>SOLUTION: The method of manufacturing the carrier comprises: mixing a coating agent for coating carrier core material to a supercritical fluid in a dissolved state; causing the mixed fluid of mixed coating agent and supercritical fluid to contact with the carrier core material; reducing a pressure of a system which includes the mixed fluid and the carrier core material brought into contact with the mixed fluid up to a pressure lower than the pressure for forming the mixed fluid and a pressure exceeding the atmospheric pressure; circulating and reusing the fluid after reducing the pressure as the supercritical fluid which is mixed with the coating agent for coating the carrier core material, thereby applying the coating agent on the surface of the carrier core material. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a carrier which is a constituent material of a two-component developer as a color toner used in a dry development method as a printing method for electrophotography and the like, and a method for manufacturing the carrier.

  The dry development method used in electrophotography forms a visible image by electrostatically adhering toner rubbed with a charging portion to an electrostatic latent image. Such a dry development method comprises a one-component development method using a one-component developer composed only of black toner such as carbon, particles called a carrier such as glass beads and magnetic particles, and a color dye. There is a two-component development system using a two-component developer as a color toner.

  In the two-component developer, the toner is fused to the surface of the carrier due to collision between particles composed of mixed particles of the carrier and the toner, and heat generation of the mixed particles due to mechanical stirring in the developing device. A so-called spent phenomenon occurs, and the charging characteristics of the carrier deteriorate with time. As a result, problems such as background contamination of the printed image and toner scattering occur due to carrier adhesion (scattering) to the electrostatic latent image carrier and generation of carrier streaks.

  In order to prevent such spending, development of a technique for preventing adhesion between the carrier and the toner by coating the carrier surface with a resin having a low surface energy, for example, a polymer resin such as a fluororesin or a silicone resin. Has been done. As such a technique, for example, a carrier coated with a room temperature curable silicone resin and a positively chargeable nitrogen resin (Patent Document 1), a carrier coated with a coating layer containing at least one modified silicone resin (Patent Document 2), A carrier having a coating layer containing a curable silicone resin and a styrene-acrylic resin (Patent Document 3), a carrier in which the core particle surface is coated with two or more layers of silicone resin so that there is no adhesion between the layers (Patent Document) 4) A carrier in which a silicone resin is coated on the surface of a core particle (Patent Document 5), a carrier whose surface is coated with a silicone resin containing silicon carbide (Patent Document 6), and a material exhibiting a critical surface tension of 20 dyn / cm or less A positively chargeable carrier coated with (Patent Document 7), a carrier coated with a coating layer containing a fluorine alkyl acrylate. And A, patent applications, such as in Patent Document 1 to 8, such as a developer comprising a toner containing a containing chromium azo dye (Patent Document 8) have been made.

  In recent years, the toner tends to have a smaller particle size in order to improve the image quality, and as a result, the above-described spent tends to occur. In addition, some of the conventional carriers such as Patent Documents 1 to 8 are spray-coated, and in such spray coating, it is difficult to form a uniform coating layer on the carrier surface. For this reason, it is difficult to maintain the adhesiveness and uniform thickness between the coating layer and the core material. Furthermore, in the case of a full color toner, a resin with a low softening point is used in order to obtain a sufficient color tone. Therefore, the spent amount to the carrier is increased compared to the black toner, the toner charge amount is decreased, the toner Scattering and background contamination occur. Therefore, the two-component developer has a problem that when the toner charge amount is lowered, the image density particularly in the highlight portion is easily changed, and the high image quality cannot be maintained.

  In addition, since the carrier surface has minute irregularities, the coating layer is thick in the recesses, and unevenness occurs such that the coating layer is thin in the projections. May not be coated. As a result, the conventional carrier has a problem that toner charging ability and stability over time are poor, causing various problems such as background stains, abnormal images, toner scattering, and the like, and it tends to cause spent on the carrier.

  Furthermore, since the conventional carriers such as Patent Documents 1 to 8 use an organic solvent when forming a coating layer on the surface of the carrier core material, volatile organic compound (VOC) regulation by the organic solvent, generation of waste liquid, There are also problems in the manufacturing process that require dry energy, which not only results in higher costs, but there are still many issues that need to be improved in terms of reducing the environmental burden and saving resources. Currently.

  Therefore, by using a supercritical fluid as a solvent instead of the conventional organic solvent as described above, the toner charging property, stability with time, etc. are good and low cost, no waste liquid is generated, and the drying process is performed. In order to provide a manufacturing method of a carrier that is unnecessary and has a low environmental load, patent applications such as Patent Document 9 and Patent Document 10 below have been filed.

  The techniques disclosed in Patent Document 9 and Patent Document 10 use a technique called a so-called rapid expansion method among fine particle coating techniques using a supercritical fluid as a process fluid. The rapid expansion method is a method in which a polymer resin dissolved in a supercritical fluid and core particles coexist and rapidly depressurized from supercritical pressure to atmospheric pressure. This is a technique for depositing and coating resin.

  However, in the rapid expansion method, vigorous injection is performed through the nozzle, so it is not easy to control the change in the solubility of the solute dissolved in the supercritical fluid, and it is difficult to adjust the film formation state. The particle composition cannot be made uniform, and the thickness of the film may be non-uniform. In particular, when the pressure is rapidly reduced, the solubility of the solute in the fluid becomes supersaturated, and as a result, the polymer resin itself as a solute is likely to become fine particles, and the polymer resin is formed on the surface of the core material particles. May not be easily coated.

  In general, since polymer resins have low solubility in supercritical carbon dioxide, it is difficult to coat the polymer resin on fine particles. In particular, it is very difficult to form a film having a certain thickness or more. In addition, since the amount of the polymer resin to be coated depends on the amount of the polymer resin dissolved in the treatment tank, depending on the amount required to form a film with the desired thickness on the surface of the core material There is also a problem that the volume of the tank for performing the treatment must be increased.

Japanese Patent Laid-Open No. 55-127469 Japanese Patent Laid-Open No. 55-157751 JP-A-56-140358 JP-A-57-96355 JP-A-57-96356 JP 58-207054 A JP-A-61-1110161 JP-A-62-273576 JP 2007-72444 A JP 2006-106208 A

  The present invention has been made to solve the above-described problems, does not require an organic solvent, does not require high energy, can freely control the film thickness, and can form a thick film. Another object of the present invention is to provide a carrier as a constituent material of a two-component developer having no uniform agglomeration between particles and a uniform film composition, and a method for producing the same.

  The present invention has been made to solve such a problem. In one aspect, the coating agent for coating the carrier core material is mixed with a supercritical fluid in a dissolved state, and the mixed coating agent and the supercritical fluid are mixed. The mixed fluid with the fluid is brought into contact with the carrier core, and then the pressure of the system including the mixed fluid and the carrier core in contact with the mixed fluid is set to a pressure lower than the pressure for forming the mixed fluid. And by reducing the pressure to a pressure exceeding the atmospheric pressure, the surface of the carrier core material is coated with a coating agent, and the reduced pressure fluid is circulated as a supercritical fluid for mixing with the coating agent covering the carrier core material. And a carrier manufacturing method characterized by being reused.

  In another aspect, the present invention is a system in which a coating agent that coats a carrier core material is mixed with a supercritical fluid in a dissolved state, and a mixed fluid of the mixed coating agent and supercritical fluid is brought into contact with the carrier core material. Is reduced to a pressure lower than the pressure for forming the mixed fluid and exceeding the atmospheric pressure, thereby depositing a coating on the surface of the carrier core material, thereby reducing the pressure for forming the mixed fluid. By reusing the fluid decompressed to a lower pressure as a supercritical fluid for mixing with the coating material that coats the carrier core material, and repeatedly depositing the coating material on the surface of the carrier core material, Provided is a method for producing a carrier, which comprises coating a surface of a carrier core material with a coating agent.

  In such a carrier production method, it is also possible to mix fine particles into the carrier core material, and to bring the mixed fluid of the coating agent and the supercritical fluid into contact with the mixture of the carrier core material and the fine particles. Further, the pressure can be reduced to a pressure lower than the pressure for forming the mixed fluid and exceeding the atmospheric pressure, and the temperature can be raised to a temperature higher than the temperature for forming the mixed fluid.

  The present invention also provides a carrier manufactured by the carrier manufacturing method as described above.

  Furthermore, the present invention provides a carrier manufacturing apparatus that implements the carrier manufacturing method as described above. A more specific configuration of such a manufacturing apparatus is a solution that contains a coating material that coats a carrier core material, supplies a supercritical fluid, and mixes and dissolves the supercritical fluid and the coating material in a dissolved state. A tank 4 and a coating film forming tank 5 for containing the carrier core material and bringing the mixed fluid of the coating agent and the supercritical fluid mixed in the dissolution tank 4 into contact with the carrier core material; By setting the internal pressure to a pressure lower than the pressure in the dissolution tank 4 and exceeding the atmospheric pressure, a coating agent is deposited on the surface of the carrier core material in the film formation tank 5, The fluid discharged from the formation tank 5 is supplied to the dissolution tank 4 and reused as a supercritical fluid for dissolving the coating agent that coats the carrier core, and the supercritical fluid is combined with the dissolution tank 4. The carrier core material is circulated through the coating film forming tank 5. By repeating the precipitation of the coating agent to, those made of a coating agent to the surface of the carrier core material so as to be able to coating.

  In such a carrier manufacturing apparatus, the pressure in the dissolution tank 4 is set to the first stage pressure for dissolving the low molecular weight preliminary coating material having a molecular weight smaller than that of the coating material to be finally used. By setting the pressure in the forming tank 5 to be lower than the pressure in the first stage in the dissolution tank 4, the low molecular weight preliminary coating agent is deposited on the surface of the carrier core material in the film forming tank 5. The pressure in the dissolution tank 4 is set to a second stage pressure in which the supercritical fluid and the coating agent are mixed in the dissolved state, and the pressure in the film formation tank 5 is set to the second pressure in the dissolution tank 4. By setting the pressure lower than the step pressure, the coating agent can be deposited on the surface of the carrier core material in the film forming tank 5.

  It is also possible to connect a line 63 in which a mixed fluid of a coating agent and a supercritical fluid is supplied from the dissolution tank 4 to the film forming tank 5 to the bottom of the film forming tank 5. Further, in addition to the carrier core material, fine particles can be accommodated in the film forming tank 5.

  In the present invention, since the supercritical fluid in which the coating agent for carrier coating is dissolved can be continuously brought into contact with the carrier core material or the carrier core material and the fine particles, the surface of the carrier core material is coated with the coating agent or fine particles. Thus, it is possible to uniformly coat the complexed coating agent, and to form a uniform film.

  Furthermore, by changing the temperature and pressure conditions and the number of times for circulating the fluid, the thickness of the film can be easily controlled.

  Furthermore, since the continuous coating process can be performed by circulating and reusing the supercritical fluid as described above, it is not necessary to increase the tank volume of the dissolution tank or the film forming tank, and the conventional rapid expansion method is used. There is an advantage that the volume of the treatment tank can be reduced as compared with the techniques such as Patent Documents 9 and 10.

  Furthermore, since it is a method using a supercritical fluid, it is not necessary to use an organic solvent conventionally used for dissolving a polymer resin or the like, and problems such as environmental problems and solvent residues hardly occur. There is an effect.

  Hereinafter, embodiments of the present invention will be described.

  In one aspect, the present invention is a carrier manufacturing method for manufacturing a carrier as a component of a two-component developer for dry development including a carrier and a toner, wherein the coating for coating the carrier core material is dissolved. Mixed with the supercritical fluid in a state, the mixed fluid of the mixed coating agent and the supercritical fluid is brought into contact with the carrier core, and then the mixed fluid and the system including the carrier core in contact with the mixed fluid The coating material is coated on the surface of the carrier core material by reducing the pressure of the carrier fluid to a pressure lower than the pressure for forming the mixed fluid and exceeding the atmospheric pressure, and the fluid after the pressure reduction is applied to the carrier. The present invention provides a method for producing a carrier, which is circulated and reused as a supercritical fluid for mixing with a coating agent for coating a core material.

  According to another aspect of the present invention, a coating material for coating the carrier core material is mixed with the supercritical fluid in a dissolved state, and the mixed fluid of the mixed coating material and the supercritical fluid is brought into contact with the carrier core material. The pressure of the system is reduced to a pressure lower than the pressure for forming the mixed fluid and exceeding the atmospheric pressure, thereby depositing a coating on the surface of the carrier core material, and the pressure for forming the mixed fluid By reusing the fluid depressurized to a lower pressure as a supercritical fluid for mixing with the coating material that coats the carrier core material, and repeatedly depositing the coating material on the surface of the carrier core material The present invention provides a method for producing a carrier, which comprises coating a surface of a carrier core material with a coating agent.

  Here, “mixing the coating material in a dissolved state with the supercritical fluid” means mixing the coating material with the supercritical fluid so that the coating material is dissolved in the supercritical fluid. The “pressure for forming a mixed fluid” is a pressure at which the supercritical fluid and the coating agent are mixed in the dissolved state after the coating agent is dissolved in the supercritical fluid.

  It is known that when an organic substance such as a polymer resin that can be used as a coating agent is dissolved in a supercritical fluid, the solubility C (saturated solubility) of the polymer resin varies depending on the temperature T and the pressure P. In general, under the condition of a constant temperature T, the solubility C of the polymer resin increases rapidly when the pressure P exceeds the critical pressure Pc of the fluid as a supercritical fluid, and the solubility C increases under higher pressure conditions. Becomes sluggish. Further, under the condition of a constant pressure P, the solubility C of the polymer resin tends to increase as the temperature T decreases.

  This change will be described with reference to the schematic diagram of FIG. In FIG. 1, the horizontal axis indicates pressure P, and the vertical axis indicates solubility C. A single line indicates a change in solubility C at temperature T, and is called a solubility isotherm. For example, when a mixed fluid in which a polymer resin is dissolved at a concentration of C11 is brought into contact with a supercritical fluid under conditions of temperature T1 and pressure P1, the temperature of T1 and pressure of P2 (P1> P2) Under the conditions, the solubility of the polymer resin decreases from C11 to C12. And the effect | action that the polymer resin for the reduced amount precipitates on the surface of a carrier core material arises.

  The operation when the temperature T1 is kept constant and the pressure is reduced from P1 to P2 is as described above, but the same operation occurs when the temperature is changed with the pressure. That is, when the temperature condition is selected so that the solubility under the condition of the pressure P2 is smaller than the solubility C11 of the polymer resin under the condition of the temperature T1 and the pressure P1, the polymer is suitably used as the carrier core material. The resin is coated.

  For example, using FIG. 1, the conditions of temperatures T2, T1, and T0 that are C22, C12, and C02, which are lower in solubility than C11, can be applied, but the condition of temperature T3 because C32 is higher than C11. Is not applicable.

  As described above, a specific unit amount of the polymer resin is deposited and coated on the surface of the carrier core material by a single decompression operation from P2 to P1. Since the fluid after being circulated and reused as a supercritical fluid for mixing the coating agent for coating the carrier core material in a dissolved state, the precipitation step as described above will be repeated, As a result, a unit amount of the coating layer is sequentially deposited on the surface of the carrier core material.

  Furthermore, in the present invention, as described above, the coating agent for coating the carrier core material is mixed with the supercritical fluid in a dissolved state, and the mixed fluid of the mixed coating agent and the supercritical fluid is used only for the carrier core material. Alternatively, it can be brought into contact with a mixture of the carrier core material and fine particles.

  Furthermore, in the present invention, the pressure is reduced to a pressure lower than the pressure for forming the mixed fluid and exceeding the atmospheric pressure, and the temperature is increased to a temperature equal to or higher than the temperature for forming the mixed fluid. It is also possible to do. Here, the “temperature for forming a mixed fluid” is a temperature at which the supercritical fluid and the coating agent are mixed in the dissolved state after the coating agent is dissolved in the supercritical fluid.

  In the case of the above conditions (P1> P2, T1 <T0), the density of the supercritical fluid at the pressure P1 and the temperature T1 is higher than the density at the pressure P2 and the temperature T0. Under such conditions, the effect of reducing the solubility of the polymer resin in the supercritical fluid more effectively occurs.

  Examples of the supercritical fluid include carbon dioxide (critical temperature: 31.1 ° C., critical pressure: 7.38 MPa), nitrous oxide (critical temperature: 36.4 ° C., critical pressure: 7.24 MPa), and trifluoromethane (critical). Temperature (25.9 ° C., critical pressure: 4.84 MPa), nitrogen (critical temperature: −147 ° C., critical pressure: 3.39 MPa), or the like can be used. In particular, it is particularly preferable to use carbon dioxide from the viewpoint of work safety and industrialization potential.

  In addition to the supercritical fluid, an entrainer (cosolvent) can also be added. By adding such an entrainer, the solubility of the coating agent can be improved. The type of entrainer is not particularly limited and can be appropriately selected according to the purpose, but a polar organic solvent is preferable.

  Examples of the polar organic solvent include methanol, ethanol, propanol, butanol, hexane, toluene, ethyl acetate, chloroform, dichloromethane, ammonia, melamine, urea, thioethylene glycol, and the like. Among these, lower alcohol solvents that exhibit poor solvent properties at normal temperature and normal pressure (25 ° C., 0.1 MPa) are preferable.

  Further, as the coating agent, for example, a polymer material such as a synthetic resin is used. Examples of synthetic resins include amino resins, polyvinyl resins, polystyrene resins, halogenated olefin resins, polyester resins, polycarbonate resins, polyethylene resins, polyvinyl fluoride resins, polyvinylidene fluoride resins, polytrifluoroethylene resins. , Polyhexafluoropropylene resin, copolymer of vinylidene fluoride and acrylic monomer, copolymer of vinylidene fluoride and vinyl fluoride, tetrafluoroethylene, vinylidene fluoride and non-fluorinated monomer Fluoroterpolymers such as terpolymers, silicone resins and the like can be used.

  These may be used individually by 1 type and may use 2 or more types together. Among these, a silicone resin is particularly preferable because of its high effect. There is no restriction | limiting in particular as a silicone resin, According to the objective, it can select suitably from the silicone resin generally known. For example, a straight silicone resin represented by the following structural formula is suitable.

  In the structural formula, R represents a hydrogen atom, a hydroxyl group, an alkoxy group, an alkyl group, or an aryl group. Examples of the alkoxy group include a methoxy group and an ethoxy group. Examples of the alkyl group include a methyl group, an ethyl group, and a propyl group. Furthermore, examples of the aryl group include a phenyl group, a tolyl group, and a xylyl group.

  The weight average molecular weight (Mw) of the silicone resin as the coating resin is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 500 to 100,000, more preferably 1000 to 10,000. In addition, the silicone resin as the coating resin is particularly excellent in handling property, film formability, and film thickness control property in the solid state at room temperature and normal pressure (25 ° C., 0.1 MPa) than in the liquid. preferable. The silanol concentration of the silicone resin as the coating resin is preferably 1 to 40% by mass, more preferably 1 to 20% by mass, and still more preferably 1 to 10% by mass for crosslinking after film formation. When the silanol concentration exceeds 40% by mass, the crosslinked film tends to be hard and brittle, and on the contrary, durability is deteriorated, and unreacted silanol groups are likely to remain, resulting in poor environmental stability of the carrier. There is. Here, as a method for measuring the silanol concentration, for example, the Karl-Fischer titration method described in Japanese Industrial Standard (JIS) K0068 “Method for Measuring Moisture of Chemical Products” can be used. . Note that all adjustments of the sample amount and titration solvent are in accordance with this.

  As said silicone resin, what was synthesize | combined suitably may be used and a commercial item may be used. As a commercial product, as a straight silicone resin, KR271, KR255, KR152 manufactured by Shin-Etsu Chemical Co., Ltd .; SR2400, SR2406, SR2410, 217 Flakes Resin, 220 Flakes Resin, 233 Flakes Resin manufactured by Toray Dow Corning Silicone Co., Ltd. 249 Flake Resin, Z-6018 Intermediate, and the like. Examples of the modified silicone resin include KR206 (alkyd modified), KR5208 (acrylic modified), ES1001N (epoxy modified), KR305 (urethane modified) manufactured by Shin-Etsu Chemical Co., Ltd .; manufactured by Toray Dow Corning Silicone Co., Ltd. SR2115 (epoxy modification), SR2110 (alkyd modification), and the like. It is possible to use the silicone resin alone, but it is also possible to simultaneously use a component that undergoes a crosslinking reaction, a charge amount adjusting component, and the like.

  As described above, a synthetic resin is mainly used as the polymer material. However, the present invention can be applied to a polymer material such as a synthetic rubber or a natural resin. Furthermore, it is possible to use not only a polymer material but also a low molecular compound. Furthermore, it is possible to use not only an organic coating agent but also an inorganic coating agent such as a metal material or ceramic, and the kind of the material of the coating agent is not questioned.

  Further, the type of carrier core material is not particularly limited, and can be appropriately selected from known ones as two-component carriers for electrophotography according to the purpose. For example, ferrite, magnetite, iron, nickel, etc. Can be used. In addition, in consideration of the environmental aspects that have advanced remarkably in recent years, if ferrite, for example, Mn ferrite, Mn-Mg ferrite, Mn-Mg-Sr ferrite, etc. should be used instead of conventional copper-zinc ferrite. Is preferred. The carrier core material preferably has a volume average particle size of 20 μm or more from the viewpoint of prevention of carrier adhesion (scattering) to the electrostatic latent image carrier, and prevents image quality deterioration such as prevention of carrier streaks. From the point of view, those having a size of 100 μm or less are preferable, and in particular, the volume average particle size is more preferably 20 to 50 μm for the recent high image quality. Further, as the shape of the carrier, a spherical or irregular particle shape can be mainly used.

  The temperature at which the coating agent is dissolved in the supercritical fluid is preferably equal to or higher than the critical temperature of the supercritical fluid, but is not particularly limited and can be appropriately selected according to the purpose. 100 ° C. is preferred. The pressure at which the coating agent is dissolved with the supercritical fluid is not particularly limited and can be appropriately selected according to the purpose, but is preferably 10 to 80 MPa. Further, the temperature at which the coating layer is formed on the surface of the core material is preferably equal to or higher than the critical temperature, but is not particularly limited and can be appropriately selected according to the purpose. 100 degreeC is preferable and 20-80 degreeC is more preferable. When the said temperature exceeds 100 degreeC, a core material may melt | dissolve. The pressure for forming the coating layer on the surface of the core material is preferably not less than the critical pressure of the supercritical fluid, but is not particularly limited and can be appropriately selected according to the purpose. Is preferred. However, the pressure needs to exceed atmospheric pressure.

  Further, as the fine particles, for example, inorganic fine particles such as metal powder and various metal oxide particles are suitably used. Among these, particles of metal oxides such as silicon oxide, titanium oxide, and alumina can easily obtain particles having a uniform fine particle diameter, and various electrical characteristics and mechanical strength are obtained depending on the particles used. be able to. In addition, a carrier that is thermally stable can be obtained even when the carrier is heated to a high temperature in the process of condensation curing of the silicone resin.

  The fine particles are particularly preferably fine particles having a higher hardness than the silicone resin constituting the coating layer of the carrier. This increases the strength of the carrier coating layer in order to prevent the carrier coating layer from deteriorating due to wear when in contact between the carrier and the carrier, between the carrier and the toner, or between the carrier and the developing device inner surface. It is because it aims at that.

Further, specifically, conductive ZnO, Al or the like metal powders, SnO ₂ doped with SnO ₂ and various elements produced by various methods, TLB _2, ZnB _2, such borides MoB _2, carbonized Silicon and conductive polymers (polyacetylene, polyparaphenylene, poly (para-phenylene sulfide), polypyrrole, parylene), alumina, carbon black, and the like can be used. Among them, alumina or carbon black nanoparticles are preferable because it is important to uniformly disperse them in the coating polymer resin.

  The state of the coating of the polymer resin on the carrier core material cannot be uniquely determined, but for example, a coating of about 500 nm on the carrier core material is preferable. Furthermore, when the fine particles are combined, a content of about 10% is preferable with respect to the coated polymer resin.

  Furthermore, the present invention provides a carrier manufacturing apparatus that implements the carrier manufacturing method as described above. A more specific configuration of such a manufacturing apparatus is a solution that contains a coating material that coats a carrier core material, supplies a supercritical fluid, and mixes and dissolves the supercritical fluid and the coating material in a dissolved state. A tank 4 and a coating film forming tank 5 for containing the carrier core material and bringing the mixed fluid of the coating agent and the supercritical fluid mixed in the dissolution tank 4 into contact with the carrier core material; By setting the internal pressure to a pressure lower than the pressure in the dissolution tank 4 and exceeding the atmospheric pressure, a coating agent is deposited on the surface of the carrier core material in the film formation tank 5, The fluid discharged from the formation tank 5 is supplied to the dissolution tank 4 and reused as a supercritical fluid for dissolving the coating agent that coats the carrier core, and the supercritical fluid is combined with the dissolution tank 4. The carrier core material is circulated through the coating film forming tank 5. By repeating the precipitation of the coating agent to, those made of a coating agent to the surface of the carrier core material so as to be able to coating.

  In such a carrier manufacturing apparatus, the pressure in the dissolution tank 4 is set to the first stage pressure for dissolving the low molecular weight preliminary coating agent having a molecular weight smaller than that of the coating agent, and the pressure in the film forming tank 5 is set. By setting the pressure to a pressure lower than the pressure in the first stage in the dissolution tank 4, the low molecular weight preliminary coating agent is deposited on the surface of the carrier core material in the film forming tank 5, and the dissolution tank 4 is set to a second stage pressure in which the supercritical fluid and the coating agent are mixed in a dissolved state, and the pressure in the film forming tank 5 is set higher than the second stage pressure in the dissolution tank 4. By setting the pressure low, the coating agent can be deposited on the surface of the carrier core material in the film forming tank 5.

  Here, “low molecular weight preliminary coating agent” means a compound having the same chemical composition as the coating agent and having a molecular weight smaller than that of the coating agent. For example, when the coating agent is a polymer resin. A polymer of monomers constituting the polymer resin, which is a compound having a lower degree of polymerization than the polymer resin.

  Since the compound having a lower molecular weight has higher solubility in the fluid, the apparatus is operated by setting the inside of the dissolution tank 4 to a first stage pressure lower than the pressure for forming the mixed fluid of the supercritical fluid and the coating agent. Thus, the low molecular weight preliminary coating agent is first deposited on the carrier core material in the film forming tank 5, and then the second stage pressure, that is, the mixed fluid of the supercritical fluid and the coating material is formed in the dissolution tank 4. When the apparatus is operated with the pressure set for the above, a polymer resin or the like having a high molecular weight is deposited on the carrier core material in the film forming tank 5, and the coating agent made of the polymer resin or the like is the carrier core. The material will be coated.

  As a result, the low molecular weight preliminary coating agent that adheres with a uniform thin film thickness acts on the polymer resin that is subsequently laminated to act as a so-called adhesive, and the overall thickness of the laminated coating layer is reduced. This is a more reliable state.

  Furthermore, it is also possible to connect a line 63 in which a mixed fluid of a coating agent and a supercritical fluid is supplied from the dissolution tank 4 to the film forming tank 5 to the bottom of the film forming tank 5. By connecting the line 63 to the bottom side of the film forming tank 5, the positions of the fluid inlet and outlet in the film forming tank 5 can be separated, and between the inlet and outlet in the film forming tank 5. The possibility of a fluid short circuit can be reduced. As a result, the contact efficiency between the fluid and the carrier core material can be prevented from being deteriorated, and a more uniform film can be formed.

  Hereinafter, more specific embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 2 is a schematic block diagram of a manufacturing apparatus for carrying out the carrier manufacturing method of one embodiment. As shown in FIG. 2, the manufacturing apparatus for carrying out the manufacturing method of this embodiment includes a gas cylinder 1, a cooling tank 2, a pump 3, a dissolution tank 4, and a film forming tank 5.

  The gas cylinder 1 is a cylinder filled with carbon dioxide for forming a supercritical fluid, and carbon dioxide as a fluid is supplied from the gas cylinder 1 into the system. In order to stably transfer carbon dioxide as liquefied carbon dioxide into the system, a siphon tube type is preferable.

  The cooling tank 2 is a tank for temporarily storing liquid carbon dioxide to be supplied to the pump 3, and includes a tank body 2a and a lid body 2b. The cooling tank 2 includes a cooler 21, a thermometer 22, and a pressure gauge 23 for cooling the carbon dioxide supplied via the gas cylinder 1 or the circulation line 6 until it becomes a stable liquid carbon dioxide state. ing. The cooling tank 2 is preferably a pressure vessel that can withstand a high pressure equal to or higher than the pressure inside the gas cylinder 1.

  The pump 3 is for supplying the liquid carbon dioxide cooled in the cooling tank 2 to the dissolution tank 4. In order to stably transfer the liquid, a positive displacement pump such as a plunger type or a diaphragm type is preferable.

  The dissolution tank 4 is a tank for dissolving a polymer resin, which is a film forming resin, in supercritical carbon dioxide, and includes a tank body 4a and a lid body 4b. In the dissolution tank 4, there are a temperature control device 41, a thermometer 42, a stirring device 43 for increasing the contact efficiency between supercritical carbon dioxide and the polymer resin, a pressure gauge 44, and a solid undissolved polymer resin. A filter 45 for preventing the liquid from flowing out of the dissolution tank 4 is provided, and a pressure adjusting valve 46 for adjusting the pressure in the dissolution tank 4 to be constant is provided in the dissolution tank. 4 is provided outside the outlet portion.

  A more specific configuration of the stirring device 43 will be described. The stirring device 43 provided in the dissolution tank 4 includes a stirring shaft 11 and a stirring blade 12 as shown in FIG. Is equipped with a magnetic induction stirrer 20. The magnetic induction stirrer 20 has a configuration in which an external magnet 15 is internally mounted in a holder 14 that is externally fitted to a sleeve 13, and as shown by a two-dot chain line in FIG. A belt 16 is wound around a pulley 18 that is rotated by a driving force.

  An inner magnet 19 is attached to the upper part of the stirring shaft 11, and the inner magnet 16 is housed in the holder 14 so as to face the outer magnet 15, and is rotated by the driving force of the motor 17. The rotational force of the pulley 18 is transmitted to the holder 14 via the belt 16 and the holder 14 rotates, and the inner magnet 19 rotates in synchronization with the outer magnet 15 mounted inside the holder 14, thereby stirring. The stirring blade 12 is configured to rotate via the shaft 11. The stirring blade 12 provided in the stirring device 43 of the dissolution tank 4 is an anchor blade formed in a substantially U shape as shown in FIG. As shown in the figure, the stirring blade 12 is provided so as to be relatively close to the bottom surface and the side surface so as not to cause a dead space between the bottom surface and the side surface of the dissolution tank 4 as much as possible. Is desirable.

  The film forming tank 5 contains a carrier core material for coating the polymer resin, and a mixed fluid of the polymer resin and the supercritical fluid is brought into contact with the carrier core material so that the polymer resin is applied to the surface of the carrier core material. It is a tank for covering, and is composed of a tank body 5a and a lid 5b. The film forming tank 5 is provided with a temperature adjusting device 51, a thermometer 52, a stirring device 53, a pressure gauge 54, and a filter 55 for preventing the carrier from flowing out of the film forming tank 5. Further, a pressure adjusting valve 56 for adjusting the pressure in the coating film forming tank 5 to be kept constant is provided outside the outlet portion of the coating film forming tank 5.

  Similarly to the stirring device 43 of the dissolution tank 4, the stirring device 53 of the film forming tank 5 includes a stirring shaft 31 and a stirring blade 32, and a magnetic induction stirrer is provided above the stirring shaft 31. 40. The configuration of the magnet induction stirrer 40 also includes a sleeve 33, a holder 34, an outer magnet 35, a belt 36, a motor 37, a pulley 38, and an inner magnet 39, similarly to the stirring device 43 of the dissolution tank 4.

  The configuration of the stirring blade 32 of the stirring device 53 of the film forming tank 5 is different from that of the stirring blade 12 of the stirring device 43 of the dissolution tank 4. That is, as shown in FIG. 4, the stirring blade 32 of the stirring device 53 of the coating film forming tank 5 includes substantially circular plates 32a and 32a, and the stirring shaft 31 is inserted into the center of the plates 32a and 32a. In addition, end portions of a plurality of outer spiral frames 32b are attached to peripheral portions of the plates 32a and 32a, and the plurality of outer spiral frames 32b are spirally formed between the upper and lower plates 32a and 32a. It is arranged to draw the orbit.

  A plurality of inner straight frames 32c are attached to the inside of the outer spiral frame 32b, and the plurality of inner straight frames 32c are also arranged between the upper and lower plates 32a and 32a. As shown in FIG. 5, an interposition body 32d is interposed between the central hole of the plate 32a and the stirring shaft 31, and a substantially fan-shaped hole 32e is formed in the periphery of the plate 32a. Yes. Further, a blade 32f is formed on the lower surface side of the plate 32a as shown in FIG. By forming the blade 32f, the stirring effect on the lower side of the plate 32a becomes better.

  When a mixed fluid of a supercritical fluid in which a polymer resin is dissolved in the dissolution tank 4 and the polymer resin is supplied to the film formation tank 5, the pressure adjustment valve 56 forms a film rather than the pressure in the dissolution tank 4. Since the pressure in the layer 5 is set low, the solubility of the polymer resin in the fluid decreases, and the polymer resin that cannot be completely dissolved is deposited on the surface of the carrier core material to form a film. Further, a polymer resin, which is a film forming resin, is accommodated in the dissolution tank 4, the polymer resin is dissolved in the dissolution tank 4 by introducing a supercritical fluid, and the film formation tank 5 is separated from the dissolution tank 4. By accommodating the carrier core material, it is possible to efficiently contact only the polymer resin dissolved in the supercritical fluid with the carrier core material, so that the excess polymer resin adheres to the carrier core material inadvertently. There is no such thing as inadvertent formation of aggregates and lumps.

  Furthermore, a line 61 between the cooling tank 2 and the pump 3, a line 62 between the pump 3 and the dissolution tank 4, a line 63 between the dissolution tank 4 and the film formation tank 5, and a line 64 between the film formation tank 5 and the cooling tank 2. Thus, a circulation flow path 6 is formed in which the fluid supplied from the cooling tank 2 is returned to the cooling tank 2. The line 63 between the dissolution tank 4 and the film formation tank 5 is connected to the upper side of the dissolution tank 4 and the upper side of the film formation tank 5, as shown in FIG.

  Next, an embodiment of a method for manufacturing a carrier using the carrier manufacturing apparatus as described above will be described.

  First, a polymer resin which is a film forming resin is accommodated in the dissolution tank 4, and a carrier core material is accommodated in the film formation tank 5. In addition, it is desirable that the dissolution tank 4 contains an amount more than the minimum amount of the polymer resin necessary for coating the carrier core material.

  Next, carbon dioxide is supplied from the gas cylinder 1 to the cooling tank 2. At this time, the supplied carbon dioxide is cooled and condensed in the cooling tank 2. In order to transport the condensed carbon dioxide stably and quantitatively, it is preferable that the density of carbon dioxide is high. In order to increase the density of carbon dioxide, the operating temperature of the cooling bath 2 is preferably about −10 ° C. Under the temperature condition of −10 ° C., the density of liquefied carbon dioxide is about 1 g / ml. At this time, the pressure inside the cooling tank 2 is substantially equal to the internal pressure of the gas cylinder 1. The internal pressure of the gas cylinder 1 is generally in the range of about 3.5 MPa to about 6.5 MPa.

  Next, the condensed and liquefied carbon dioxide is transferred to the dissolution tank 4 by the pump 3. At this time, the temperature control device 41 is set so as to maintain the temperature inside the dissolution tank 4 at or above the critical temperature of carbon dioxide. Further, the pressure regulating valve 46 is set so that the pressure inside the dissolution tank 4 is maintained at a pressure higher than the critical pressure of carbon dioxide. With these settings, the inside of the dissolution tank 4 is maintained at a temperature higher than the critical temperature of carbon dioxide and a pressure higher than the critical pressure, thereby forming supercritical carbon dioxide.

  The supercritical carbon dioxide formed in the dissolution tank 4 dissolves the polymer resin by coming into contact with the polymer resin previously stored in the dissolution tank 4. The stirring device 43 can further improve the dissolution efficiency of the polymer resin in supercritical carbon dioxide.

  The operation of the stirring device 43 will be described. First, when the pulley 18 is rotated by driving the motor 17, the rotational force of the pulley 18 is transmitted to the holder 14 via the belt 16, and the holder 14 rotates. The rotation of the holder 14 causes the inner magnet 19 to rotate in synchronization with the outer magnet 15 mounted inside the holder 14, thereby rotating the stirring blade 12 via the stirring shaft 11. By rotating the stirring blade 12 in this manner, the polymer resin is suitably stirred in supercritical carbon dioxide, and the polymer resin is suitably dissolved in supercritical carbon dioxide.

  Next, the liquefied carbon dioxide is continuously transferred to the dissolution tank 4 by the pump 3 and the pressure in the dissolution tank 4 is maintained by the pressure adjusting valve 46, and the pressure in the film formation tank 5 is further set to the pressure. The pressure is set to be kept lower than the pressure in the dissolution tank 4 by the adjusting valve 56. Therefore, excessively liquefied carbon dioxide supplied to the dissolution tank 4 is transferred to the film formation tank 5 through the line 63 via the pressure regulating valve 46. At this time, the polymer resin dissolved together with the supercritical carbon dioxide is transferred to the film forming tank 5.

  In addition, it is possible to generate a certain pressure difference between the dissolving tank 4 and the film forming tank 5 by using a back pressure valve, a flow rate adjusting valve or the like instead of the pressure adjusting valves 46 and 56 as described above. It is.

  Thus, when supercritical carbon dioxide in which the polymer resin is dissolved in a state close to saturation in the dissolution tank 4 is supplied to the coating film formation tank 5 in a pressure atmosphere lower than the pressure in the dissolution tank 4, As the density of carbon dioxide decreases, the solubility of the polymer resin in supercritical carbon dioxide decreases, and as a result, a polymer resin that cannot be completely dissolved is deposited. In general, the polymer resin is deposited on the surface of the carrier core material to finally form a film.

  Further, in this case, the dispersion state of the carrier core material in the film forming tank 5 is maintained using the stirring device 53 installed in the film forming tank 5, and the precipitation of the polymer resin and the film on the surface of the carrier core material are performed. Can be promoted. As a result, almost all polymer resins are deposited on the surface of the carrier core material.

  Finally, the carbon dioxide inside the film forming tank 5 is in a state containing almost no polymer resin, and is returned to the cooling tank 2 having a lower pressure via the pressure regulating valve 56 and the line 64. In this case, since the filter 55 is provided at the fluid outlet of the film forming tank 5, the carrier coated with the polymer resin is not inadvertently discharged outside the film forming tank 5.

  The carbon dioxide returned to the cooling tank 2 via the line 64 is condensed in the cooling tank 2 and supplied again to the dissolution tank 4 by the pump 3. Thereafter, the polymer resin is transferred to the surface of the carrier core material by the above-described effects. It will be coated.

  If it carries out as mentioned above, it will become possible to limit the quantity of the polymeric resin coat | covered with a carrier core material in one circulation process to a specific value. As a result, it is possible to laminate a polymer resin on the surface of the carrier core material by repeating this process continuously, and the coating state becomes uniform. Furthermore, the film thickness to be grown can be controlled by selecting the number of repetitions. Furthermore, by increasing the number of repetitions, a thick film can be finally formed.

  In the present embodiment, the pressure in the cooling tank 2 can be circulated and reused in a high pressure state without reducing the pressure to the atmospheric pressure, and an energy saving process can be realized.

  Further, by continuously bringing carbon dioxide in which the polymer resin is dissolved into contact with the carrier core material as described above, even if the polymer resin has low solubility with respect to supercritical carbon dioxide, a thick coating is formed on the carrier core material. Can be formed.

(Embodiment 2)
This embodiment is another embodiment of a method for manufacturing a carrier. In the present embodiment, in addition to the pump 3 for supplying the liquid carbon dioxide cooled in the cooling tank 2 to the dissolution tank 4, as shown in FIG. A pump 7 for supplying directly to the dissolution tank 4 without passing through is separately provided. This embodiment is different from the first embodiment in that a pump 7 for directly supplying the liquid carbon dioxide in the gas cylinder 1 to the dissolution tank 4 is provided.

  Thus, since the liquid carbon dioxide in the gas cylinder 1 is directly supplied to the dissolution tank 4 via the pump 7, the liquid carbon dioxide in the gas cylinder 1 is not supplied to the cooling tank 2 unlike the first embodiment. . Therefore, although not shown in FIG. 6, the pipe connecting the cylinder 1 and the pump 7 is provided with a cooler for cooling the liquid carbon dioxide passing through the pipe.

  In this embodiment, since the line for supplying liquid carbon dioxide from the gas cylinder 1 to the cooling tank 2 is not provided as described above, a line 61 for supplying liquid carbon dioxide cooled to the pump 3 is provided in the cooling tank 2. Only two lines, a line 64 for returning carbon dioxide from the film forming tank 5 to the cooling tank 2, are provided.

  A gas tank 1, a cooling tank 2, a pump 3, a dissolution tank 4, and a coating film forming tank 5 are provided to constitute a carrier manufacturing apparatus, and each of the cooling tank 2, the dissolution tank 4, and the coating film formation tank 5. Since the circuit 61, the line 61, the line 62, the line 63, and the line 64 are the same as those in the first embodiment, the description thereof is omitted.

  In the present embodiment, carbon dioxide is supplied from the gas cylinder 1 to the dissolution tank 4 via the pump 7. At this time, the carbon dioxide is cooled and condensed by a cooler installed in a pipe connecting the gas cylinder 1 and the pump 7. Even when carbon dioxide is directly supplied from the gas cylinder 1 to the dissolution tank 4 via the pump 7 as described above, carbon dioxide is supplied from the gas cylinder 1 to the dissolution tank 4 via the cooling tank 2 as in the first embodiment. Similarly, the higher the density of carbon dioxide, the better. Accordingly, the set temperature of the cooler in this case is preferably about −10 ° C. Under this temperature condition, the density of the liquefied carbon dioxide is about 1 g / ml as in the case of being supplied to the cooling tank 2 of the first embodiment.

  The carbon dioxide supplied to the dissolution tank 4 is maintained at a temperature equal to or higher than the critical temperature and a pressure equal to or higher than the critical pressure to form supercritical carbon dioxide, and the polymer resin accommodated in the dissolution tank 4 is suitably dissolved. The operation and action are set such that the pressure in the dissolution tank 4 is held by the pressure adjustment valve 46 of the dissolution tank 4, and the pressure in the coating film formation tank 5 is set higher than the pressure in the dissolution tank 4 by the pressure adjustment valve 56. By setting to keep a little lower, the operation and action of supplying the polymer resin dissolved together with the liquefied carbon dioxide supplied to the dissolution tank 4 to the film formation tank 5 and the polymer supplied to the film formation tank 5 The operation and action of depositing the resin on the surface of the carrier core material to form a film, and the carbon dioxide in the film forming tank 5 in a state not containing the polymer resin are transferred to the cooling tank 2 via the line 64. Return operations and actions , Is the same as the first embodiment, a detailed description thereof will be omitted.

  The carbon dioxide transferred to the cooling bath 2 via the line 64 is condensed in the cooling bath 2 and supplied to the dissolution bath 4 by the pump 3, not by the pump 7. That is, in the present embodiment, only the carbon dioxide returned to the cooling tank 2 is supplied to the dissolution tank 4 by the pump 3.

  At this time, if the pressure in the dissolution tank 4 does not reach the target value, the carbon dioxide from the gas cylinder 1 is supplied to the dissolution tank 4 together with the pump 3 that supplies the carbon dioxide returned to the cooling tank 2 to the dissolution tank 4. By operating the directly supplied pump 7, it becomes possible to replenish the deficient liquefied carbon dioxide from the gas cylinder 1 via the pump 7.

  By repeating such operations continuously, the coating state of the polymer resin on the surface of the carrier core material becomes uniform as in the first embodiment, and it is possible to grow a film to form a thick film. .

  In this embodiment, the pump 7 connected to the gas cylinder 1 sucks liquefied carbon dioxide from the gas cylinder 1, and the pump 3 connected to the cooling tank 2 sucks liquefied carbon dioxide from the cooling tank 2. Therefore, it is possible to operate the primary side pressure (suction side pressure) of each pump at different pressures.

  In this case, it is preferable to prepare the pressure regulating valve 56 so that the primary pressure (pressure on the suction side) of the pump 3 connected to the cooling tank 2 is set to a pressure exceeding the critical pressure of carbon dioxide. When the pressure regulating valve 56 is prepared in this manner, the carbon dioxide returned to the cooling tank 2 is maintained in a certain high density state, and the cooling device 21 can efficiently further increase the density of carbon dioxide. It becomes possible.

  Further, even if liquefied carbon dioxide is not newly supplied from the gas cylinder 1 to the dissolution tank 4 via the pump 7, carbon dioxide having a predetermined pressure is continuously supplied from the cooling tank 2 to the dissolution tank 4, and the coating film formation tank 5. Thus, the circulation channel 6 is suitably circulated via the.

  The pressure in the cooling tank 2 can be circulated and reused in a high pressure state without reducing the pressure to atmospheric pressure, and an energy saving process can be realized. Carbon dioxide in which a polymer resin is dissolved is continuously used as a carrier core material. Similar to the first embodiment described above, a thick film can be formed on the carrier core material even if it is a polymer resin having low solubility with respect to supercritical carbon dioxide.

(Embodiment 3)
This embodiment is still another embodiment of the carrier manufacturing method. In the present embodiment, as shown in FIG. 7, in addition to the pressure adjustment valve 46 for adjusting the pressure in the dissolution tank 4, the pressure in the dissolution tank 4 is adjusted, and the components in the dissolution tank 4 are adjusted. And a pressure regulating valve 8 for discharging to the outside of the tank. Such a pressure regulating valve 8 is not provided in that it is provided separately from the pressure regulating valve 46 provided at the inlet of the line 63 from the dissolution tank 4 to the coating film forming tank 5. This is different from the first embodiment.

  A gas tank 1, a cooling tank 2, a pump 3, a dissolution tank 4, and a coating film forming tank 5 are provided to constitute a carrier manufacturing apparatus, and each of the cooling tank 2, the dissolution tank 4, and the coating film formation tank 5. Since the circuit 61, the line 61, the line 62, the line 63, and the line 64 are the same as those in the first embodiment, the description thereof is omitted.

  In the present embodiment, after the liquefied carbon dioxide is supplied to the dissolution tank 4, the dissolution tank is not first provided by the pressure adjustment valve 8 on the discharge side to the outside of the tank, rather than the pressure adjustment valve 46 on the supply side to the coating film formation tank 5. 4 is set to hold the pressure. In this case, out of the components contained in the coating agent, components that are not necessary for film formation on the carrier core material, that is, not high molecular weight resin, for example, low molecular weight components and monomers are dissolved in supercritical carbon dioxide. When the temperature and pressure conditions are set, these impurity components are dissolved in supercritical carbon dioxide before the polymer resin, and are released from the pressure regulating valve 8 together with the supercritical carbon dioxide. In this way, impurity components such as the low molecular weight component and monomer are extracted and removed from the polymer resin.

  After the impurity components as described above are extracted and removed from the polymer resin by the pressure regulating valve 8, the pressure regulating valve 8 is closed and the pressure regulating valve 46 is opened. In this case, since the impurity component is extracted and removed from the polymer resin by the pressure regulating valve 8, the polymer resin in a state where the impurity component not necessary for the film formation is removed is supplied to the film forming tank 5. It becomes.

  In that case, while setting so that the pressure in the dissolution tank 4 may be held by the pressure adjustment valve 46, the pressure in the coating film formation tank 5 is held slightly lower than the pressure in the dissolution tank 4 by the pressure adjustment valve 56. By setting, the operation and the action of supplying the polymer resin dissolved together with the liquefied carbon dioxide supplied to the dissolution tank 4 to the film forming tank 5 are the same as in the first and second embodiments.

  Further, the operation and action of supplying carbon dioxide from the gas cylinder 1 to the cooling tank 2 to cool and condense the carbon dioxide, the operation and action of supplying condensed and liquefied carbon dioxide to the dissolution tank 4 by the pump 3, and the dissolution tank 4 An operation and an action for suitably dissolving the polymer resin contained in the dissolution tank 4 by forming the supercritical carbon dioxide by maintaining the supplied carbon dioxide at a temperature higher than the critical temperature and a pressure higher than the critical pressure. The operation and action of supplying to the film forming tank 5, the operation and action of depositing the polymer resin supplied to the film forming tank 5 on the surface of the carrier core material to form a film, and the state containing no polymer resin The operation and action of returning the carbon dioxide in the formed film forming tank 5 to the cooling tank 2 via the line 64 are the same as those in the first embodiment, and thus detailed description thereof is omitted.

  In this embodiment, since a polymer resin having a uniform composition from which impurity components such as low molecular weight components and monomers that are not necessary for film formation are removed in advance can be brought into contact with the carrier core material, more uniform properties can be obtained. A film can be formed.

  The pressure in the cooling tank 2 can be circulated and reused in a high pressure state without reducing the pressure to atmospheric pressure, and an energy saving process can be realized. Carbon dioxide in which a polymer resin is dissolved is continuously used as a carrier core material. Similar to Embodiments 1 and 2 above, a thick film can be formed on the carrier core material even if the polymer resin has low solubility in supercritical carbon dioxide.

(Embodiment 4)
This embodiment is still another embodiment of the carrier manufacturing method. In the carrier manufacturing apparatus of this embodiment, both the pump 7 used in the second embodiment and the pressure regulating valve 8 used in the third embodiment are provided.

  That is, in this embodiment, as shown in FIG. 8, in addition to the pump 3 for supplying the liquid carbon dioxide cooled in the cooling tank 2 to the dissolution tank 4, the liquid carbon dioxide in the gas cylinder 1 is directly supplied to the dissolution tank 4. A pump 7 for supplying is separately provided, and in addition to the pressure adjusting valve 46 on the supply side to the coating film forming tank 5, a pressure adjusting valve 8 for releasing part of the components in the dissolving tank 4 to the outside of the tank. Is provided separately.

  A gas tank 1, a cooling tank 2, a pump 3, a dissolution tank 4, and a coating film forming tank 5 are provided to constitute a carrier manufacturing apparatus, and each of the cooling tank 2, the dissolution tank 4, and the coating film formation tank 5. The point that the circulation channel 6 is configured by the configuration 61, the line 62, the line 62, the line 63, and the line 64 is the same as that of the first to third embodiments, and thus the description thereof is omitted.

  In the present embodiment, as in the second embodiment, carbon dioxide is first supplied from the gas cylinder 1 to the dissolution tank 4 via the pump 7, and at that time, the carbon dioxide is installed in a pipe connecting the gas cylinder 1 and the pump 7. It is cooled and condensed by the cooled cooler.

  Then, after the liquefied carbon dioxide is supplied to the dissolution tank 4 via the pump 7, the pressure in the dissolution tank 4 is maintained by the pressure adjustment valve 8 on the discharge side of the dissolution tank 4 as in the third embodiment. Set. By setting the temperature and pressure conditions in the dissolution tank 4 so that impurity components such as low molecular weight components and monomers are dissolved in the supercritical carbon dioxide by the pressure regulating valve 8 as in the third embodiment. The impurity component is dissolved in supercritical carbon dioxide prior to the polymer resin, is released together with the supercritical carbon dioxide from the pressure regulating valve 8 to the outside of the tank, and the impurity component is extracted and removed from the polymer resin. Become.

  Thereafter, the pressure regulating valve 8 is closed and the pressure regulating valve 46 is opened, so that the polymer resin in a state where impurity components unnecessary for film formation are removed is transferred to the film forming tank 5. The supplied point is the same as in the third embodiment.

  In addition, the pressure adjustment valve 46 is set to hold the pressure in the dissolution tank 4, and the pressure in the coating film formation tank 5 is set to be held slightly lower than the pressure in the dissolution tank 4 by the pressure adjustment valve 56. Thus, the operation and action of supplying the polymer resin dissolved together with the liquefied carbon dioxide supplied to the dissolution tank 4 to the coating tank 5 are the same as those in the first to third embodiments.

  Furthermore, the carbon dioxide returned to the cooling tank 2 via the line 64 is condensed in the cooling tank 2 and supplied to the dissolution tank 4 not by the pump 7 but by the pump 3 and only returned to the cooling tank 2. Is supplied to the dissolution tank 4 by the pump 3 as in the second embodiment.

  Similarly to the second embodiment, when the pressure in the dissolution tank 4 does not reach the target value, the carbon dioxide returned to the cooling tank 2 and the pump 3 for supplying the carbon dioxide to the dissolution tank 4 are combined with the carbon dioxide from the gas cylinder 1. By operating the pump 7 that directly supplies carbon to the dissolution tank 4, it becomes possible to replenish the deficient liquefied carbon dioxide from the gas cylinder 1 via the pump 7.

  Furthermore, the pump 7 connected to the gas cylinder 1 and the primary pressure (suction side pressure) of the pump 3 connected to the cooling tank 2 can be operated at different pressures. By adjusting the pressure regulating valve 56 so that the primary pressure of the pump 3 (pressure on the suction side) is set to a pressure exceeding the critical pressure of carbon dioxide, the carbon dioxide returned to the cooling tank 2 is The second embodiment is also similar to the second embodiment in that it is possible to efficiently increase the density of carbon dioxide while maintaining a high density state to some extent.

  Further, similarly to the second embodiment, carbon dioxide having a predetermined pressure is continuously supplied from the cooling tank 2 to the dissolving tank 4 without supplying liquefied carbon dioxide from the gas cylinder 1 to the dissolving tank 4 via the pump 7. It will be supplied and will circulate suitably through the circulation channel 6 via the film formation tank 5.

  Furthermore, as in the third embodiment, since a polymer resin having a uniform composition from which impurity components such as low molecular weight components and monomers that are not necessary for film formation are removed in advance can be brought into contact with the carrier core material, it is more uniform. It is possible to form a film having a proper property.

  The carbon dioxide supplied to the dissolution tank 4 is maintained at a temperature equal to or higher than the critical temperature and a pressure equal to or higher than the critical pressure to form supercritical carbon dioxide, and the polymer resin accommodated in the dissolution tank 4 is suitably dissolved. The operation and action are set such that the pressure in the dissolution tank 4 is held by the pressure adjustment valve 46 of the dissolution tank 4, and the pressure in the coating film formation tank 5 is set higher than the pressure in the dissolution tank 4 by the pressure adjustment valve 56. By setting to keep a little lower, the operation and action of supplying the polymer resin dissolved together with the liquefied carbon dioxide supplied to the dissolution tank 4 to the film formation tank 5 and the polymer supplied to the film formation tank 5 The operation and action of depositing the resin on the surface of the carrier core material to form a film, and the carbon dioxide in the film forming tank 5 in a state not containing the polymer resin are transferred to the cooling tank 2 via the line 64. Return operations and actions , Is the same as the first embodiment, a detailed description thereof will be omitted.

  The pressure in the cooling tank 2 can be circulated and reused in a high pressure state without reducing the pressure to atmospheric pressure, and an energy saving process can be realized. Carbon dioxide in which a polymer resin is dissolved is continuously used as a carrier core material. It is the same as in the first embodiment in that a thick film can be formed on the carrier core material even if it is a polymer resin having low solubility with respect to supercritical carbon dioxide.

(Embodiment 5)
This embodiment is still another embodiment of the carrier manufacturing method. In the present embodiment, of the lines 61, 62, 63, 64 forming the circulation channel 6, the line 63 between the dissolution tank 4 and the film formation tank 5 is the upper part of the dissolution tank 4, as shown in FIG. It is connected to the bottom side of the film forming tank 5 from the side, and in this respect, it is different from the first embodiment in which the upper side of the dissolution tank 4 is connected to the upper side of the film forming tank 5.

  In the line 64 between the coating film forming tank 5 and the cooling tank 2, the exit part of the line 64 from the coating film forming tank 5 is provided in the upper part of the coating film forming tank 5. And when the inlet part in the film formation tank 5 of the line 63 is provided in the upper part of the film formation tank 5 like the said Embodiment 1, the position between the inlet part and outlet part of the fluid in the film formation tank 5 is Since it becomes close, the possibility that a short circuit of the fluid between the inlet portion and the outlet portion may not be solved.

  When a short circuit of the fluid between the inlet and the outlet occurs, there is a problem that the carrier core material and the fluid cannot be efficiently contacted. Therefore, in this embodiment, since the line 63 is connected to the bottom side of the film forming tank 5 as described above, the positions of the fluid inlet and outlet in the film forming tank 5 can be separated. The possibility that a short circuit of the fluid between the inlet portion and the outlet portion in the forming tank 5 may be reduced. As a result, the contact efficiency between the fluid and the carrier core material can be prevented from being deteriorated, and a more uniform film can be formed.

  A gas tank 1, a cooling tank 2, a pump 3, a dissolution tank 4, and a coating film forming tank 5 are provided to constitute a carrier manufacturing apparatus, and each of the cooling tank 2, the dissolution tank 4, and the coating film formation tank 5. Since the circuit 61, the line 61, the line 62, the line 63, and the line 64 are the same as those in the first embodiment, the description thereof is omitted.

  Also preferred is a polymer resin that is stored in the dissolution tank 4 by forming the supercritical carbon dioxide by maintaining the carbon dioxide supplied to the dissolution tank 4 at a temperature higher than the critical temperature and a pressure higher than the critical pressure. The pressure in the dissolution tank 4 is set to be maintained by the pressure adjustment valve 46 of the dissolution tank 4 and the pressure in the dissolution tank 4 is set to the pressure in the dissolution tank 4 by the pressure adjustment valve 56. By setting so as to be kept slightly lower than that, the operation and action of supplying the polymer resin dissolved together with the liquefied carbon dioxide supplied to the dissolution tank 4 to the film formation tank 5 were supplied to the film formation tank 5. The operation and action of depositing a polymer resin on the surface of the carrier core material to form a film, and the carbon dioxide in the film forming tank 5 in a state not containing the polymer resin are cooled via a line 64 Operation to return to 2 Action is the same as the first embodiment, a detailed description thereof will be omitted.

  Furthermore, the pressure of the cooling tank 2 can be circulated and reused in a high pressure state without reducing the pressure to the atmospheric pressure, and an energy saving process can be realized. The contact with the material is the same as in Embodiment 1 in that a thick film can be formed on the carrier core material even if the polymer resin has low solubility in supercritical carbon dioxide.

(Embodiment 6)
This embodiment is still another embodiment of the carrier manufacturing method. In this embodiment, the line 63 between the dissolution tank 4 and the film formation tank 5 is connected from the upper side of the dissolution tank 4 to the bottom side of the film formation tank 5, as shown in FIG. This is common with the fifth embodiment.

  Therefore, also in this embodiment, the position of the inlet part and the outlet part of the fluid in the film forming tank 5 can be spaced apart from each other in the same manner as in the fifth embodiment, and the inlet part and the outlet part in the film forming tank 5 are separated. There is an effect that it is possible to reduce the possibility of a fluid short circuit.

  In the present embodiment, as in the second embodiment, in addition to the pump 3 for supplying the liquid carbon dioxide cooled in the cooling tank 2 to the dissolving tank 4, as shown in FIG. A separate pump 7 for supplying the liquid carbon dioxide directly to the dissolution tank 4 without passing through the cooling tank 2 is provided.

  Therefore, in this embodiment, the liquid carbon dioxide in the gas cylinder 1 is directly supplied to the dissolution tank 4 via the pump 7 as in the second embodiment, and is not supplied to the cooling tank 2. For this reason, carbon dioxide transferred to the cooling tank 2 via the line 64 is condensed in the cooling tank 2 and supplied to the dissolution tank 4 by the pump 3 instead of the pump 7 as in the second embodiment. Only the carbon dioxide returned to the cooling bath 2 is supplied to the dissolution bath 4 by the pump 3.

  For this reason, as in the second embodiment, when the pressure in the dissolution tank 4 does not reach the target value, together with the pump 3 that supplies the carbon dioxide returned to the cooling tank 2 to the dissolution tank 4, the gas tank 1 By operating the pump 7 that directly supplies the carbon dioxide to the dissolution tank 4, it becomes possible to replenish the deficient liquefied carbon dioxide from the gas cylinder 1 via the pump 7.

  Also, the pump 7 connected to the gas cylinder 1 can suck liquefied carbon dioxide from the gas cylinder 1, and the pump 3 connected to the cooling tank 2 can suck liquefied carbon dioxide from the cooling tank 2. Therefore, it is the same as that of the second embodiment in that the primary pressure (suction side pressure) of each pump can be operated at different pressures.

  A gas tank 1, a cooling tank 2, a pump 3, a dissolution tank 4, and a coating film forming tank 5 are provided to constitute a carrier manufacturing apparatus, and each of the cooling tank 2, the dissolution tank 4, and the coating film formation tank 5. The point that the circulation flow path 6 is configured by the configuration 61, the line 62, the line 62, the line 63, and the line 64 is the same as that of the first to fifth embodiments, and thus the description thereof is omitted.

  Also preferred is a polymer resin that is stored in the dissolution tank 4 by forming the supercritical carbon dioxide by maintaining the carbon dioxide supplied to the dissolution tank 4 at a temperature higher than the critical temperature and a pressure higher than the critical pressure. The pressure in the dissolution tank 4 is set to be maintained by the pressure adjustment valve 46 of the dissolution tank 4 and the pressure in the dissolution tank 4 is set to the pressure in the dissolution tank 4 by the pressure adjustment valve 56. By setting so as to be kept slightly lower than that, the operation and action of supplying the polymer resin dissolved together with the liquefied carbon dioxide supplied to the dissolution tank 4 to the film formation tank 5 were supplied to the film formation tank 5. The operation and action of depositing a polymer resin on the surface of the carrier core material to form a film, and the carbon dioxide in the film forming tank 5 in a state not containing the polymer resin are cooled via a line 64 Operation to return to 2 Act, is the same as in Embodiment 1 to 5, a detailed description thereof will be omitted.

  Furthermore, the pressure of the cooling tank 2 can be circulated and reused in a high pressure state without reducing the pressure to atmospheric pressure, and an energy saving process can be realized. Carbon dioxide in which a polymer resin is dissolved is continuously used as a carrier core material. It is the same as in the first to fifth embodiments that a thick film can be formed on the carrier core material even if it is a polymer resin having low solubility with respect to supercritical carbon dioxide.

(Embodiment 7)
This embodiment is still another embodiment of the carrier manufacturing method. In this embodiment, the line 63 between the dissolution tank 4 and the film formation tank 5 is connected from the upper side of the dissolution tank 4 to the bottom side of the film formation tank 5, as shown in FIG. Common to Embodiments 5 and 6 above.

  Therefore, also in this embodiment, the positions of the inlet and outlet of the fluid in the film forming tank 5 can be separated as in the fifth and sixth embodiments, and the inlet and outlet in the film forming tank 5 can be separated. There is an effect that it is possible to reduce the possibility that a fluid short circuit occurs.

  In the present embodiment, as in the third embodiment, in addition to the pressure adjustment valve 46 for adjusting the pressure in the dissolution tank 4, the pressure in the dissolution tank 4 is adjusted as shown in FIG. In addition, a pressure regulating valve 8 for releasing a part of the components in the dissolution tank 4 to the outside of the tank is provided separately. Similar to the third embodiment, such a pressure regulating valve 8 is provided separately from the pressure regulating valve 46 provided at the inlet portion of the line 63 from the dissolution tank 4 to the film forming tank 5.

  Therefore, in the present embodiment, as in the third embodiment, after the liquefied carbon dioxide is supplied to the dissolution tank 4, the pressure in the dissolution tank 4 is first held by the pressure regulating valve 8 on the discharge side to the outside of the tank. . In that case, among the components contained in the coating agent, by setting the conditions of temperature and pressure at which impurity components such as low molecular weight components and monomers are dissolved in supercritical carbon dioxide, those impurities are formed as in the third embodiment. The components are dissolved in supercritical carbon dioxide prior to the polymer resin, and are released from the pressure regulating valve 8 together with the supercritical carbon dioxide to remove impurities such as low molecular weight components and monomers from the polymer resin. Will be.

  After the impurity components as described above are extracted and removed from the polymer resin by the pressure regulating valve 8, the pressure regulating valve 8 is closed and the pressure regulating valve 46 is opened to form a film. In the same manner as in the third embodiment, the polymer resin in a state where impurity components unnecessary for the above are removed is supplied to the film forming tank 5. Accordingly, even in this embodiment, since a polymer resin having a uniform composition from which impurity components such as low molecular weight components and monomers that are not necessary for film formation are removed can be contacted with the carrier core material more uniformly. A characteristic film can be formed.

  A gas tank 1, a cooling tank 2, a pump 3, a dissolution tank 4, and a coating film forming tank 5 are provided to constitute a carrier manufacturing apparatus, and each of the cooling tank 2, the dissolution tank 4, and the coating film formation tank 5. Since the circulation channel 6 is configured by the configuration 61, the line 61, the line 62, the line 63, and the line 64, the description is omitted.

  Also preferred is a polymer resin that is stored in the dissolution tank 4 by forming the supercritical carbon dioxide by maintaining the carbon dioxide supplied to the dissolution tank 4 at a temperature higher than the critical temperature and a pressure higher than the critical pressure. The pressure in the dissolution tank 4 is set to be maintained by the pressure adjustment valve 46 of the dissolution tank 4 and the pressure in the dissolution tank 4 is set to the pressure in the dissolution tank 4 by the pressure adjustment valve 56. By setting so as to be kept slightly lower than that, the operation and action of supplying the polymer resin dissolved together with the liquefied carbon dioxide supplied to the dissolution tank 4 to the film formation tank 5 were supplied to the film formation tank 5. The operation and action of depositing a polymer resin on the surface of the carrier core material to form a film, and the carbon dioxide in the film forming tank 5 in a state not containing the polymer resin are cooled via a line 64 Operation to return to 2 Act, is the same as in Embodiment 1 to 6, a detailed description thereof will be omitted.

  Furthermore, the pressure of the cooling tank 2 can be circulated and reused in a high pressure state without reducing the pressure to atmospheric pressure, and an energy saving process can be realized. Carbon dioxide in which a polymer resin is dissolved is continuously used as a carrier core material. In the same manner as in the first to sixth embodiments, a thick film can be formed on the carrier core material even if it is a polymer resin having low solubility in supercritical carbon dioxide.

(Embodiment 8)
This embodiment is still another embodiment of the carrier manufacturing method. In this embodiment, the line 63 between the dissolution tank 4 and the film formation tank 5 is connected from the upper side of the dissolution tank 4 to the bottom side of the film formation tank 5, as shown in FIG. Common to Embodiments 5 to 7 above.

  Therefore, also in this embodiment, the positions of the inlet and outlet of the fluid in the film forming tank 5 can be separated as in the fifth to seventh embodiments, and the inlet and outlet in the film forming tank 5 can be separated. There is an effect that it is possible to reduce the possibility that a fluid short circuit occurs.

  In this embodiment, as shown in FIG. 12, in addition to the pump 3 for supplying the liquid carbon dioxide cooled in the cooling tank 2 to the dissolution tank 4, the liquid carbon dioxide in the gas cylinder 1 is directly supplied to the dissolution tank 4. A pump 7 for supplying is separately provided, and in addition to the pressure adjusting valve 46 on the supply side to the coating film forming tank 5, a pressure adjusting valve 8 for releasing part of the components in the dissolving tank 4 to the outside of the tank. Is provided separately. This point is common to the fourth embodiment.

  Therefore, in the present embodiment, the liquid carbon dioxide in the gas cylinder 1 is directly supplied to the dissolution tank 4 via the pump 7 and transferred to the cooling tank 2 via the line 64 as in the second, fourth, and sixth embodiments. Since carbon dioxide is condensed in the cooling tank 2 and supplied to the dissolution tank 4 by the pump 3, only the carbon dioxide returned to the cooling tank 2 is supplied to the dissolution tank 4 by the pump 3. For this reason, when the pressure of the dissolution tank 4 does not reach the target value, the carbon dioxide from the gas cylinder 1 is supplied to the dissolution tank 4 together with the pump 3 that supplies the carbon dioxide returned to the cooling tank 2 to the dissolution tank 4. By operating the directly supplied pump 7, it becomes possible to replenish the deficient liquefied carbon dioxide from the gas cylinder 1 via the pump 7. Also, the pump 7 connected to the gas cylinder 1 can suck liquefied carbon dioxide from the gas cylinder 1, and the pump 3 connected to the cooling tank 2 can suck liquefied carbon dioxide from the cooling tank 2. For this reason, it is possible to operate the primary side pressure (pressure on the suction side) of each pump at different pressures.

  On the other hand, in the present embodiment, as in the third, fourth, seventh, etc., after the liquefied carbon dioxide is supplied to the dissolution tank 4, first, the pressure inside the dissolution tank 4 is adjusted by the pressure adjustment valve 8 on the discharge side to the outside of the tank. Pressure is maintained. In that case, among the components contained in the coating agent, by setting the conditions of temperature and pressure at which impurity components such as low molecular weight components and monomers are dissolved in supercritical carbon dioxide, those impurities are formed as in the third embodiment. The components are dissolved in supercritical carbon dioxide prior to the polymer resin, and are released from the pressure regulating valve 8 together with the supercritical carbon dioxide to remove impurities such as low molecular weight components and monomers from the polymer resin. Will be.

  After the impurity components as described above are extracted and removed from the polymer resin by the pressure regulating valve 8, the pressure regulating valve 8 is closed and the pressure regulating valve 46 is opened to form a film. The polymer resin in a state in which impurity components unnecessary for coating are removed is supplied to the film forming tank 5, and therefore, the low molecular weight components and monomers such as monomers that are not necessary for film formation are removed in advance. Since a polymer resin having a proper composition can be brought into contact with the carrier core material, a film having a more uniform property can be formed as in the third, fourth and seventh embodiments.

  A gas tank 1, a cooling tank 2, a pump 3, a dissolution tank 4, and a coating film forming tank 5 are provided to constitute a carrier manufacturing apparatus, and each of the cooling tank 2, the dissolution tank 4, and the coating film formation tank 5. The point that the circulation channel 6 is configured by the configuration 61, the line 62, the line 62, the line 63, and the line 64 is the same as that of the first to seventh embodiments, and thus the description thereof is omitted.

  Also preferred is a polymer resin that is stored in the dissolution tank 4 by forming the supercritical carbon dioxide by maintaining the carbon dioxide supplied to the dissolution tank 4 at a temperature higher than the critical temperature and a pressure higher than the critical pressure. The pressure in the dissolution tank 4 is set to be maintained by the pressure adjustment valve 46 of the dissolution tank 4 and the pressure in the dissolution tank 4 is set to the pressure in the dissolution tank 4 by the pressure adjustment valve 56. By setting so as to be kept slightly lower than that, the operation and action of supplying the polymer resin dissolved together with the liquefied carbon dioxide supplied to the dissolution tank 4 to the film formation tank 5 were supplied to the film formation tank 5. The operation and action of depositing a polymer resin on the surface of the carrier core material to form a film, and the carbon dioxide in the film forming tank 5 in a state not containing the polymer resin are cooled via a line 64 Operation to return to 2 Act, is the same as in Embodiment 1 to 7, a detailed description thereof will be omitted.

  Furthermore, the pressure of the cooling tank 2 can be circulated and reused in a high pressure state without reducing the pressure to atmospheric pressure, and an energy saving process can be realized. Carbon dioxide in which a polymer resin is dissolved is continuously used as a carrier core material. In the same manner as in the first to seventh embodiments, a thick film can be formed on the carrier core material even if the polymer resin has low solubility in supercritical carbon dioxide.

(Embodiment 9)
This embodiment is still another embodiment of the carrier manufacturing method. In the present embodiment, after the carbon dioxide is in a supercritical state, the apparatus is operated by changing the pressure in the dissolution tank 4, and in this respect, the above-described operation in which the inside of the dissolution tank 4 was operated at the same pressure. This is different from the first to eighth embodiments.

  For example, the pressure in the dissolution tank 4 can be varied in two stages by adjusting the pressure regulating valve 46, such as operating at 12 MPa for 60 minutes and then operating at 18 MPa for 60 minutes.

  Thus, by operating the apparatus by changing the pressure in two stages, when the operation is performed at a low pressure in the first stage, the low molecular weight coating agent is dissolved and supplied to the film forming tank 5, The low molecular weight coating material is laminated on the carrier core material with a uniform thin film thickness, and then the high molecular weight coating material with a higher molecular weight is dissolved by operating at the second higher pressure. The high molecular weight coating agent is supplied to the film forming tank 5 and laminated on the carrier core material.

  Therefore, in this embodiment, by operating the inside of the dissolution tank 4 at the first lower pressure, the coating agent having a low molecular weight first adheres to the carrier core in the film formation tank 5, and then the dissolution tank 4 By operating the inside at a high pressure in the second stage, the polymer resin, which is a coating agent having a high molecular weight, is laminated on the carrier core material and coated with the polymer resin in the film forming tank 5.

  As a result, the low molecular weight coating material that adheres with a uniform thin film thickness acts on the polymer resin that is subsequently laminated so as to be a so-called adhesive, and the film thickness of the entire laminated coating layer is more reliably increased. It becomes a state.

  In addition, as a carrier manufacturing apparatus used in the present embodiment, any one of Embodiments 1 to 8 can be used.

(Other embodiments)
In each of the embodiments described above, the case where the carrier core material is coated with the polymer resin has been described. However, the carrier core material is coated with the polymer resin, and the polymer resin is embedded with fine particles. It is also possible to combine fine particles.

  In that case, although it differs from each said embodiment in the point which accommodates a predetermined amount of carrier core materials with microparticles | fine-particles in the film formation tank 5 in each said embodiment, the other operation method is the same as that of said each embodiment. Therefore, the carrier manufacturing apparatus of each of the above embodiments can also be used when the fine particles are combined.

  In the coating film forming tank 5, the coating of the polymer resin on the surface of the carrier core material and the adhesion of the fine particles to the polymer resin occur at the same time. It will be formed on the surface of the core material.

  In each of the above embodiments, a pressure difference is provided between the dissolution tank 4 and the film forming tank 5, and the carrier core material is coated with a difference in solubility of the polymer resin for film formation with respect to supercritical carbon dioxide. In addition to such a method by pressure adjustment, a difference in solubility of the polymer resin for film formation in supercritical carbon dioxide can also be obtained by providing a temperature difference between the dissolution tank 4 and the film formation tank 5. It is possible to turn on.

  For example, when the pressures of both the dissolution tank 4 and the film formation tank 5 are the same, the temperature of the film formation tank 5 may be set higher than the temperature of the dissolution tank 4. Then, it becomes possible to make the solubility of the polymer resin with respect to carbon dioxide in the coating film forming tank 5 lower than the solubility of the polymer resin with respect to carbon dioxide in the dissolving tank 4. Inside, the polymer resin is deposited on the surface of the carrier core material to form a film.

  Furthermore, when the pressure in the dissolution tank 4 is higher than the pressure in the film formation tank 5 as in the above embodiments, the temperature of the film formation tank 5 is set higher than the temperature of the dissolution tank 4, thereby 4, the solubility of the polymer resin in carbon dioxide in the film forming tank 5 can be further lowered than the solubility of the polymer resin in carbon dioxide in the film 4, and as a result, the carrier in the film forming tank 5 can be reduced. Precipitation and coating of the polymer resin on the surface of the core material are promoted.

  On the other hand, when the pressure in the dissolution tank 4 is higher than the pressure in the film formation tank 5 as in the above embodiments, even if the temperature of the film formation tank 5 is lower than the temperature of the dissolution tank 4, By setting the density of carbon dioxide in the film forming tank 5 lower than that in the dissolving tank 4, the solubility of the polymer resin in carbon dioxide in the dissolving tank 4 is higher than that in the film forming tank 5. The solubility of the polymer resin can be lowered. As a result, the polymer resin can be deposited on the surface of the carrier core material in the coating film forming tank 5 and formed into a film.

  The density of supercritical carbon dioxide is determined by determining the temperature and pressure. The higher the density, the higher the solubility of the polymer resin in supercritical carbon dioxide. Further, under the same density condition, the higher the temperature, the higher the solubility of the polymer resin in supercritical carbon dioxide. In short, it is important to lower the solubility of the polymer resin in supercritical carbon dioxide in the coating film formation tank 5 than in the dissolution tank 4 by adjusting the density conditions inside the dissolution tank 4 and the coating film formation tank 5. That's it.

  The density of supercritical carbon dioxide at a certain temperature and pressure can be estimated using a general gas equation of state.

  Further, in each of the above embodiments, carbon dioxide (critical temperature: 31.1 ° C., critical pressure: 7.38 MPa) is used as the supercritical fluid, but in addition to this, nitrous oxide (critical temperature: 36.4 ° C.). , Critical pressure: 7.24 MPa), trifluoromethane (critical temperature: 25.9 ° C., critical pressure: 4.84 MPa), nitrogen (critical temperature: −147 ° C., critical pressure: 3.39 MPa), etc. it can. Among these, it is particularly preferable to use carbon dioxide from the viewpoint of industrialization such as environmental load and cost.

  Regarding the devices used in each of the above embodiments, general materials such as high-pressure vessel materials, piping materials, equipment types, line filters, check valves, drain valves, bypass piping, safety valves, mounts, etc., not shown Appropriate parts can be selected and used as appropriate.

  In addition, regarding the apparatus used in the above-described embodiment, the stirring apparatus 43 provided in the dissolution tank 4 is preferably one that increases the contact efficiency between the polymer resin and the supercritical fluid, and the shape is not particularly limited. The stirrer 53 provided in the coating film forming tank 5 is intended to laminate a film of a polymer resin or a mixture of polymer resin and inorganic fine particles on the surface of the carrier, and does not damage the once laminated film. A stirring device having characteristics is particularly preferred.

  Examples of the present invention will be described below.

Example 1
In this embodiment, for the purpose of producing a carrier used for a two-component developer, a coating polymer resin in which alumina (Al ₂ O ₃ ) as fine particles is dispersed in ferrite particles as a carrier core material. An example in which the coating material B (silicone resin) as a laminate is coated will be described.

  Before setting the experimental conditions, the solubility of coating material B (KR220L: manufactured by Shin-Etsu Chemical Co., Ltd.), which is a coating polymer resin for supercritical carbon dioxide, was examined. Using a general flow-type supercritical extraction apparatus having a high-pressure cell with an internal volume of 50 ml as an experimental apparatus, the solubility was measured under the conditions where the flow rate of carbon dioxide was 3 ml / min and the extraction time was 6 hours. The solubility was evaluated using the extraction rate (% by weight) calculated as the ratio of the extraction weight to the weight of the coating material B initially charged in the high-pressure cell. The measurement result of the extraction rate is shown in FIG.

  From the results shown in FIG. 13, as conditions for a large change in the extraction rate (solubility) when the pressure is reduced, the temperature is 20 MPa at a pressure of 20 MPa in the dissolution tank (condition 1), and the temperature is 40 ° C. at a pressure of 10 MPa in the film formation tank It was decided to drive in 2). By setting this condition, the density of carbon dioxide inside the dissolution tank is set to 0.78 g / ml, and the density of carbon dioxide inside the film formation tank is set to 0.63 g / ml. We decided to set the density of carbon dioxide inside to a small value (estimated value based on the state equation of gas).

  Further, as apparent from FIG. 13, the extraction rate of the coating material B under the condition 1 is 53%, and the extraction rate of the coating material B under the condition 2 is 25%, and it is possible to provide a sufficient solubility difference. I understood.

  Furthermore, in this example, the fluid was sufficiently circulated in the apparatus by setting the flow rate of liquefied carbon dioxide by the pump to 60 ml / min and the operation time to 60 minutes.

  Therefore, the carrier was coated with the coating material B using the apparatus of Embodiment 3 shown in FIG. First, 60 parts by weight of the coating material B was dissolved in a dissolving tank, 30 parts by weight of a ferrite core material having a volume average particle size of 35 μm (saturated magnetic moment at 1 k gauss = 65 emu / g), and alumina (Sumicorundum AA-03: Sumitomo). 6 parts by weight of Chemical Industry Co., Ltd. was put into the film forming tank.

  First, in order to remove the low molecular weight material that is not suitable for the coating of the carrier core material from the coating material B put in the dissolution tank, continuous supply of carbon dioxide was started by a pump. The flow rate of carbon dioxide was adjusted to a liquefied carbon dioxide flow rate of 3 ml / min, the pressure of the dissolution tank was adjusted to 10 MPa, the temperature was adjusted to 40 ° C., and supercritical carbon dioxide was circulated for 2 hours, via a pressure adjustment valve provided in the dissolution tank. Then, the low molecular weight material was removed from the coating material B.

  As a result of analyzing the weight average molecular weight of the removed substance by the GPC method, Mw = 1000. Further, after extracting and removing the low molecular weight, a part of the sample of the coating material B remaining in the dissolution tank was taken out and analyzed for the weight average molecular weight. As a result, it was found that Mw = 3000. The weight average molecular weight of the coating material B before removing the low molecular weight was Mw = 2500, and it was found that the low molecular weight was suitably removed by the treatment.

Next, continuous supply of carbon dioxide was started by a pump. The flow rate of carbon dioxide was set to a mass flow rate of 35 g / min, a volume flow rate of about 18 L / min (after conversion to standard state CO ₂ ), and a liquefied carbon dioxide flow rate of 60 ml / min. The pressure in the dissolution tank was adjusted to 20 MPa, and the temperature was adjusted to 50 ° C. Moreover, the pressure of the film formation tank was adjusted to 10 MPa, and the temperature was adjusted to 40 ° C. The operation time of the apparatus was 60 minutes.

  As a result of the experiment, a carrier in which the coating material B in which alumina was dispersed was coated could be manufactured. About 25 of the obtained carrier particles, the composition of the coating was analyzed using an energy dispersive X-ray spectrometer (EDS). The results are shown in Table 1.

As is apparent from Table 1, alumina (Al ₂ O ₃ ) composited in the coating of coating material B, coating material B (metal component Si) which is a coating forming resin, and ferrite (Fe, Mn) as a carrier The standard deviations of Si, Al, Mn, and Fe mainly contained in (3) were all small. In addition, in order to evaluate the coating amount of the coating material B or alumina on the ferrite as a carrier per unit amount, the standard values normalized with the Mn value as the reference (1.0) are also shown in Table 1. It turned out that the film | membrane composition of the carrier manufactured by the present Example is uniform.

(Comparative Example 1)
Using the same amount of carrier core material, coating material B, and charge control agent as in Example 1, coated particles were produced by the conventional supercritical carbon dioxide rapid expansion method. That is, it is not a method of growing a film on the surface of the carrier inside the film forming tank, but a method of forming the coating material B on the surface of the carrier by rapidly reducing the mixture of the coating material B and the carrier to atmospheric pressure.

  The pressure of the dissolution tank was adjusted to 20 MPa, the temperature was adjusted to 50 ° C., and the coating material B was sufficiently dissolved in supercritical carbon dioxide by stirring for 60 minutes. Subsequently, the atmosphere was released, and the carrier was coated with the coating material B and the charge control agent inside the coating film forming tank.

  Moreover, as the coating material B, the thing which removed the thing of the low molecular weight performed in Example 1 was used.

  In addition, since it is the conditions of open | release to air | atmosphere, the carbon dioxide with which the inside of a dissolution tank and a film formation tank was open | released by air | atmosphere and only discharge | released outside, it does not circulate fluid.

  As a result of the experiment, the film composition was measured for 70 particles by EDS in the same manner as in Example 1. The results are shown in Table 2.

As is apparent from Table 2, it is contained in alumina (Al ₂ O ₃ ) embedded in the coating of coating material B, coating material B (metal component Si) that is a coating forming resin, and ferrite (Fe, Mn). The standard deviations for Si, Al, Mn, and Fe were larger than those in Example 1. Therefore, it was found that the film composition of the coated composite particles produced in Comparative Example 1 was non-uniform compared to Example 1.

Furthermore, as a result of comparison using standard values, the content of Si in the formed film is
0.3 ÷ 2.2 = about 1/7, and it was found that the result of Comparative Example 1 was lower than that of Example 1 by about 1/7.

  As a result, the thickness of the carrier manufactured in Example 1 was thicker than that of Comparative Example 1, and the effectiveness of the present invention was confirmed.

(Example 2)
In this example, similarly to Example 1, for the purpose of producing a carrier used for a two-component developer, ferrite particles as a carrier core material and alumina (Al ₂ O ₃ ) as fine particles are used. This is an example in which a coating material B (silicone resin) as a dispersed coating polymer resin is laminated and coated.

  In the present example, the coating material B was coated on the carrier using the apparatus of the seventh embodiment shown in FIG. This is different from Example 1 tested using the apparatus of Embodiment 3.

  In this example, 30 parts by weight of the coating material B is used in a dissolution tank, 60 parts by weight of a ferrite core material having a volume average particle size of 35 μm (saturated magnetic moment at 1 k gauss = 65 emu / g), and alumina (Sumicorundum AA- 03: Sumitomo Chemical Co., Ltd.) was added together in a film-forming tank. Then, in the same manner as in Example 1, in order to remove the low molecular weight material that is not suitable for coating the carrier core material from the coating material B introduced into the dissolution tank, continuous supply of carbon dioxide was started by a pump. The flow rate of carbon dioxide was adjusted to a liquefied carbon dioxide flow rate of 3 ml / min, the pressure of the dissolution tank was adjusted to 10 MPa, the temperature was adjusted to 40 ° C., and supercritical carbon dioxide was circulated for 2 hours, via a pressure adjustment valve provided in the dissolution tank. Then, the low molecular weight material was removed from the coating material B.

  Next, continuous supply of carbon dioxide was started by a pump. In this example, the melting tank was operated at a pressure of 18 MPa and a temperature of 50 ° C. (condition 1), and the coating film forming tank was operated at a pressure of 10 MPa and a temperature of 35 ° C. (condition 2). Further, the operation was carried out with the flow rate of liquefied carbon dioxide by the pump being 4 L / min (atmospheric pressure gas standard) and the operation time being 120 minutes.

  As a result of the experiment, a carrier in which the coating material B in which alumina was dispersed was coated could be manufactured. About 5 of the obtained carrier particles, the composition of the coating was analyzed using an energy dispersive X-ray spectrometer (EDS). The results are shown in Table 3. Moreover, about the obtained carrier particle, the result analyzed using the ZSX100e type | mold (made by Rigaku) fluorescent X-ray-measurement apparatus was made into the average value B, and also normalized using the analysis value of Fe of the average value B Table 3 shows the standard value B as a value.

Here, the standard values in Table 3 and the standard values in Table 2 of Comparative Example 1 are compared. As a result, the adhesion amount of the alumina (Al ₂ O ₃ ) compounded in the coating of the coating material B is 1.1, which is almost the same, but there is almost no difference. ) Was found to be about 2.3 times (0.7 ÷ 0.3) more in Example 2 than in Comparative Example 1. That is, although the pressure in the dissolution tank is as low as 18 MPa in this Example 2 compared to 20 MPa in Comparative Example 1, the coating on the carrier core material in the coating tank is performed under the operating conditions of this Example. It was proved that the film thickness of the agent can be increased.

  Further, the obtained carrier was heated at 180 ° C. for 1 hour, and the following evaluation test was performed.

[Evaluation]
<Forced deterioration evaluation of carrier particles>
Place 20g of carrier in a 50ml bottle made of glass, set it on a shaker YS-8D manufactured by Yayoi Co., Ltd., shake for 60 minutes with 90 reciprocal amplitudes per minute, and carrier resistance after shaking The carrier film thickness was evaluated as follows. The results are shown in Table 5.

<Carrier resistance>
Carrier resistance means the volume resistivity of electrical resistance, and was measured by the following method using 4261A manufactured by Yokogawa-HEWLETT-PACKARD. As shown in FIG. 14, a carrier C is filled in a cell C made of a fluororesin container containing an electrode a and an electrode b each having a distance between electrodes of 2 mm and a surface area of 2 × 4 cm, and a tapping machine PTM-1 manufactured by Sankyo Piotech Co., Ltd. Using the mold, a tapping operation was performed for 1 minute at a tapping speed of 30 times / minute. A DC voltage of 1000 V was applied between both electrodes, DC resistance was measured by a high resistance meter 4329A (4329A + LJK 5HLVLVWDQFH 0HWHU, manufactured by Yokogawa Hewlett-Packard Co., Ltd.), electric resistivity RΩ · cm was determined, and LogR was calculated.

<Carrier layer thickness>
The Si / Fe ratio Si / Fe value was calculated from the film composition value and used as a film thickness index indicating the film thickness. Here, the composition ratio of Si and Fe in the carrier can be measured using, for example, a ZSX100e type (manufactured by Rigaku Corporation) fluorescent X-ray measurement apparatus. Specifically, first, as a treatment of a measurement sample, a carrier is uniformly attached to a seal obtained by applying an adhesive on a polyester film. This can be obtained by setting it on a measurement sample stage and measuring the Si and Fe strength in the sample.

-Changes in carrier resistance-
After initial and forced deterioration tests at an applied voltage of 1,000 V, the respective carrier resistances are measured, the change is 0 to 10%, ◎ 11 to 20% is ◯, 21 to 30% is △, Those with 30% or more were rated as x.

-Changes in carrier film thickness-
From the comparison between the initial stage and after the forced deterioration test, the residual ratio was set as ◎, 89-80% as ○, 79-70% as △, and 69-0% as x.

  As is clear from Table 5, in this example, the film thickness change, the resistance change, and the overall evaluation were both evaluated as ◯, that is, the residual ratio was within a range of 89 to 80%.

(Example 3)
In this example, similarly to Examples 1 and 2, for the purpose of producing a carrier used for a two-component developer, ferrite particles as a carrier core material and alumina (Al ₂ O ₃ as fine particles) are used. ) Is coated with a coating material B (silicone resin) as a coating polymer resin dispersed. Also in the present example, the apparatus of the seventh embodiment shown in FIG.

  Also in this example, similarly to Example 2, 30 parts by weight of the coating material B was dissolved in a dissolution tank, and a ferrite core material having a volume average particle size of 35 μm (saturated magnetic moment at 1 k gauss = 65 emu / g) was 60. Part by weight and 3 parts by weight of alumina (Sumicorundum AA-03: manufactured by Sumitomo Chemical Co., Ltd.) were charged together in the film forming tank. Then, in the same manner as in Examples 1 to 3, an operation of removing a low molecular weight material not suitable for coating the carrier core material from the coating material B put into the dissolution tank was performed.

  In this example, after the carbon dioxide was in a supercritical state, the apparatus was operated by changing the pressure in the dissolution tank 4. More specifically, after the operation of the dissolution tank 4 is first performed at 12 MPa and 50 ° C., the condition of the coating film formation tank 5 is 9.5 MPa and 35 ° C. for 60 minutes (step 1), the conditions of the dissolution tank 4 are subsequently changed. The conditions of 18 MPa, 50 ° C. and film forming tank 5 were operated at 8.5 MPa and 35 ° C. for 60 minutes (step 2). The operation was performed at a flow rate of liquefied carbon dioxide by the pump of 4 L / min (atmospheric pressure gas standard).

  As a result of the experiment, a carrier in which the coating material B in which alumina was dispersed was coated could be manufactured. In this example, the composition of the coating was analyzed by the fluorescent X-ray analyzer for the obtained carrier particles in the same manner as in Example 2 above. Table 4 shows the analysis results of the average value B and the standard value B.

  As is clear from Table 4, in particular, the amount of the coating material B (metal component Si), which is a film-forming resin, is found to be substantially equal to the average value B and the standard value B shown in Table 3. It was. Therefore, it was found that the film composition of the carrier manufactured in this example was as thick as that obtained in Example 2.

  Furthermore, the obtained carrier was heated at 180 ° C. for 1 hour, and the same evaluation test as in Example 3 was performed. The test method and evaluation method are the same as in Example 2. The results are shown in Table 5.

  As is clear from Table 5, in this example, the resistance change was evaluated as ◯, that is, the residual ratio was in the range of 89 to 80%, but the film thickness change and the overall evaluation were evaluated as ◎. The residual rate was in the range of 100 to 90%. Furthermore, when the carrier evaluation results of Example 2 and Example 3 are compared, Example 3 in which a plurality of processes are performed has a higher evaluation as a carrier than Example 2 in which a single process is performed. I understood.

  The carrier of the present invention can ensure the stability of the quality because the coating film is made uniform and uniform. As a result, it is suitably used for a high-quality two-component developer, a cartridge using the developer, and other printing resin equipment.

  Further, the carrier production method of the present invention is a functional material coating of general functional fine particles, for example, charge controllable fine particles, reinforcing fine particles, catalyst fine particles, drug fine particles, etc. as additives for the production of functional plastic resins. It is also applicable to.

The schematic diagram of the solubility isotherm of the polymer resin with respect to a supercritical fluid. The schematic block diagram of the carrier manufacturing apparatus as one Embodiment. The expanded sectional view of the dissolution tank in the carrier manufacturing apparatus of the embodiment. The expanded sectional view of the film formation tank in the carrier manufacturing apparatus of the embodiment. The schematic plan view of the stirring blade in the same film formation tank. The schematic block diagram of the carrier manufacturing apparatus of other embodiment. The schematic block diagram of the carrier manufacturing apparatus of other embodiment. The schematic block diagram of the carrier manufacturing apparatus of other embodiment. The schematic block diagram of the carrier manufacturing apparatus of other embodiment. The schematic block diagram of the carrier manufacturing apparatus of other embodiment. The schematic block diagram of the carrier manufacturing apparatus of other embodiment. The schematic block diagram of the carrier manufacturing apparatus of other embodiment. The graph of the solubility (extraction rate) measurement result of the coating material B with respect to supercritical carbon dioxide. The perspective view which shows the state which measures carrier resistance about the obtained carrier.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Gas cylinder 2 ... Cooling tank 3 ... Pump 4 ... Dissolution tank 5 ... Film formation tank

Claims (14)

  A carrier production method for producing a carrier as a component of a two-component developer for dry development containing a carrier and a toner, wherein a coating for coating a carrier core material is mixed with a supercritical fluid in a dissolved state, The mixed fluid of the mixed coating agent and the supercritical fluid is brought into contact with the carrier core, and then the pressure of the system including the mixed fluid and the carrier core in contact with the mixed fluid is changed to the mixed fluid formation. The pressure is reduced to a pressure lower than the pressure for the pressure and the pressure exceeding the atmospheric pressure, and the fluid after the pressure reduction is circulated and reused as a supercritical fluid for mixing with the coating agent that coats the carrier core material. A method for producing a carrier, characterized in that the surface of the carrier core material is coated with a coating agent.   A carrier production method for producing a carrier as a component of a two-component developer for dry development containing a carrier and a toner, wherein a coating for coating a carrier core material is mixed with a supercritical fluid in a dissolved state, By reducing the pressure of the system in which the mixed fluid of the mixed coating agent and the supercritical fluid is brought into contact with the carrier core material to a pressure lower than the pressure for forming the mixed fluid and higher than the atmospheric pressure. A coating agent is deposited on the surface of the carrier core material, and the pressure reduced to a pressure lower than the pressure for forming the mixed fluid is increased as a supercritical fluid for mixing with the coating material covering the carrier core material. A method for producing a carrier comprising: coating a coating on the surface of a carrier core by repeatedly reusing the coating and depositing the coating on the surface of the carrier core.   The method for producing a carrier according to claim 1 or 2, wherein fine particles are mixed in the carrier core material, and a mixed fluid of a coating agent and a supercritical fluid is brought into contact with the mixture of the carrier core material and the fine particles.   The carrier according to any one of claims 1 to 3, wherein the pressure of the carrier is reduced to a pressure lower than the pressure for forming the mixed fluid and exceeding atmospheric pressure, and the temperature is raised to a temperature equal to or higher than the temperature for forming the mixed fluid. Production method.   A carrier manufacturing method for manufacturing a carrier as a component of a two-component developer for dry development including a carrier and a toner, which contains a coating for coating a carrier core and dissolves the coating The supercritical fluid is supplied to (4), the supercritical fluid and the coating agent are mixed in a dissolved state, and the mixed fluid of the mixed coating agent and the supercritical fluid is contained in a carrier core material and the carrier A film forming tank (5) for forming a film on the core material, and the pressure in the film forming tank (5) is lower than the pressure in the dissolving tank (4) for forming the mixed fluid; By setting the pressure to be higher than the atmospheric pressure, the coating agent is deposited on the surface of the carrier core material in the film forming tank (5), and the fluid discharged from the film forming tank (5) is further discharged into the carrier core material. As a supercritical fluid for dissolving the coating agent The supercritical fluid is supplied to the dissolution tank (4) and reused, and the supercritical fluid is circulated through the dissolution tank (4) and the film formation tank (5) to deposit the coating agent on the surface of the carrier core material. By repeating the above, the carrier core material is coated with a coating agent.   The pressure in the dissolving tank (4) is set to the first stage pressure for dissolving the low molecular weight preliminary coating agent having a molecular weight smaller than that of the coating agent, and the pressure in the film forming tank (5) is set to the dissolving tank. By setting the pressure lower than the pressure in the first stage in (4), the low molecular weight preliminary coating agent is deposited on the surface of the carrier core material in the film forming tank (5), and then The pressure in the dissolution tank (4) is set to a second stage pressure in which the supercritical fluid and the coating agent are mixed in the dissolved state, and the pressure in the film formation tank (5) is set in the dissolution tank (4). The carrier manufacturing method according to claim 5, wherein the coating agent is deposited on the surface of the carrier core material in the coating film forming tank (5) by setting the pressure lower than the pressure in the second stage.   The line (63) through which the mixed fluid of the coating agent and the supercritical fluid is supplied from the dissolution tank (4) to the film forming tank (5) is connected to the bottom of the film forming tank (5). The method for producing a carrier according to 5 or 6.   A carrier manufactured by the method for manufacturing a carrier according to claim 1.   A carrier manufacturing apparatus for manufacturing a carrier as a component of a two-component developer for dry development containing a carrier and a toner, wherein a coating for coating a carrier core material is mixed with a supercritical fluid in a dissolved state, The mixed fluid of the mixed coating agent and the supercritical fluid is brought into contact with the carrier core material, and the pressure of the system including the mixed fluid and the carrier core material in contact with the mixed fluid is determined as the pressure for forming the mixed fluid. By reducing the pressure to a pressure lower than the atmospheric pressure and exceeding the atmospheric pressure, and circulating and reusing the reduced fluid as a supercritical fluid for mixing with the coating agent that coats the carrier core material An apparatus for manufacturing a carrier, characterized in that the surface of the core material can be coated with a coating agent.   A carrier manufacturing apparatus for manufacturing a carrier as a component of a two-component developer for dry development containing a carrier and a toner, wherein a coating for coating a carrier core material is mixed with a supercritical fluid in a dissolved state, By reducing the pressure of the system in which the mixed fluid of the mixed coating agent and the supercritical fluid is brought into contact with the carrier core material to a pressure lower than the pressure for forming the mixed fluid and higher than the atmospheric pressure. A coating agent is deposited on the surface of the carrier core material, and the pressure reduced to a pressure lower than the pressure for forming the mixed fluid is increased as a supercritical fluid for mixing with the coating material covering the carrier core material. The carrier core material can be coated on the surface of the carrier core material by repeating the deposition of the coating material on the surface of the carrier core material. A manufacturing equipment.   A carrier manufacturing apparatus for manufacturing a carrier as a component of a two-component developer for dry development including a carrier and a toner, containing a coating for coating a carrier core material, and supplying a supercritical fluid The dissolution tank (4) for mixing and dissolving the supercritical fluid and the coating material in a dissolved state, and the mixing of the coating material and the supercritical fluid containing the carrier core material and mixed in the dissolution tank (4) A film forming tank (5) for bringing fluid into contact with the carrier core material, and the pressure in the film forming tank (5) is lower than the pressure in the dissolving tank (4) and exceeds the atmospheric pressure. By setting the pressure, a coating agent is deposited on the surface of the carrier core material in the film formation tank (5), and the fluid discharged from the film formation tank (5) is coated with the carrier core material. Said dissolution as a supercritical fluid for dissolving the agent Supply to (4) and reuse and circulate the supercritical fluid through the dissolution tank (4) and the film formation tank (5) to repeat the deposition of the coating on the surface of the carrier core material. The carrier manufacturing apparatus is characterized in that the surface of the carrier core material can be coated with a coating agent.   The pressure in the dissolving tank (4) is set to the first stage pressure for dissolving the low molecular weight preliminary coating agent having a molecular weight smaller than that of the coating agent, and the pressure in the film forming tank (5) is set to the dissolving tank. By setting the pressure lower than the pressure in the first stage in (4), the low molecular weight preliminary coating agent is deposited on the surface of the carrier core material in the film forming tank (5), and the dissolution tank ( 4) Set the pressure in the second stage in which the supercritical fluid and the coating agent are mixed in the dissolved state, and set the pressure in the film forming tank (5) to the second pressure in the dissolving tank (4). The carrier manufacturing apparatus according to claim 11, wherein the carrier is deposited on the surface of the carrier core material in the film forming tank (5) by setting the pressure lower than the step pressure.   The line (63) through which the mixed fluid of the coating agent and the supercritical fluid is supplied from the dissolution tank (4) to the film forming tank (5) is connected to the bottom of the film forming tank (5). The manufacturing apparatus of the carrier of 11 or 12.   The carrier manufacturing apparatus according to any one of claims 9 to 13, wherein fine particles are accommodated in the film forming tank (5) in addition to the carrier core material.

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