Method for manufacturing molded body, and molding device

Abstract

A method for manufacturing a molded body according to the present invention employs a molding tool having a cavity for storing a molding material, a feature formation part provided in an inner part of the cavity, and an injection port and a discharge port for the molding material. The method is characterized by comprising: a pressure reduction step for reducing the pressure in the cavity; a first injection step for injecting the molding material into a part of the cavity through the injection port while applying pressure to the molding material at the same time as or after the start of the pressure reduction in the cavity; a second injection step for injecting the molding material into the cavity while applying pressure to the molding material at least until the cavity is filled with the molding material after the pressure reduction in the cavity has been stopped; and a curing step for curing the molding material injected into the cavity after the second injection step.

Description

Method for producing molded body, and molding apparatus

[0001] The present invention relates to a method for producing a molded body, and a molding apparatus.

[0002] Conventionally, articles having a fine structure on their surface, such as microchannel devices, have been used for applications such as DNA analysis and cell analysis. Such articles are manufactured, for example, by molding a resin using a molded body (mold) having fine features formed on its surface.

[0003] As such a mold, for example, Patent Document 1 discloses a thermoplastic molding tool and assembly for molding thermoplastic components that have precise micro-scale features and reproducible macro-scale dimensions.

[0004] Japanese Patent Publication No. 2022-511768 (Translation of PCT Application)

[0005] In recent years, with the mass production of microchannel devices and the like, there has been an increasing demand for shortening the production time and improving the quality of molded bodies having a fine structure on their surface, which can be used as molds for microchannel devices and the like. However, air may be entrained in the molding material when the molding material is stirred and mixed, or when the molding material is supplied into the cavity of the mold, and air bubbles may remain in the produced molded body, leading to quality degradation. To address such a problem, the present inventors have studied performing a defoaming treatment to remove air bubbles from the molding material. However, a long-time defoaming treatment is required to satisfactorily remove air bubbles, which may extend the production time of the molded body.

[0006] Accordingly, an object of the present invention is to provide a method for producing a molded body, which is capable of shortening the production time of the molded body while suppressing the incorporation of air bubbles into the molded body. Another object of the present invention is to provide a molding apparatus used in the above method for producing a molded body.

[0007] The inventors of the present invention conducted diligent research with the aim of solving the above problems. As a result, the inventors of the present invention discovered that when manufacturing a molded body using a molding tool, if the molding material is injected under pressure into a portion of the cavity of the molding tool while the cavity is under reduced pressure, and then, after the pressure reduction in the cavity is stopped, the molding material is injected into the cavity under pressure, it is possible to suppress the retention of air bubbles in the molded body obtained by curing the molding material and shorten the manufacturing time of the molded body, thus completing the present invention.

[0008] In other words, the present invention aims to advantageously solve the above problems, and the present invention is a method for manufacturing a molded body using a molding tool having a cavity for containing a molding material, a feature forming section provided in a part of the cavity, and an injection port and an outlet for the molding material, comprising: a depressurization step of reducing the pressure inside the cavity; a first injection step of injecting the molding material under pressure into a part of the cavity through the injection port at the same time as or after the start of depressurization inside the cavity; a second injection step of injecting the molding material under pressure into the cavity until at least the cavity is filled with the molding material, after stopping the depressurization of the cavity; and a curing step of curing the molding material injected into the cavity after the second injection step. In this way, by creating a reduced pressure inside the cavity of the molding tool, injecting molding material under pressure into a portion of the cavity, and then stopping the pressure reduction inside the cavity, and then further injecting molding material under pressure to fill the cavity, it is possible to suppress the incorporation of air bubbles into the molded body formed by the curing of the molding material, while also shortening the manufacturing time of the molded body.

[0009] [2] In the method for manufacturing the molded article described in [1] above, it is preferable that the injection port is located vertically below the discharge port. By positioning the injection port vertically below the discharge port in the molding tool, the incorporation of air bubbles into the resulting molded article can be further suppressed.

[0010] [3] The method for manufacturing a molded article according to [1] or [2] above preferably further includes a pressure degassing step of pressurizing and degassing the molding material before the first injection step. If the molding material to be injected in the first injection step is pre-pressurized and degassed, the incorporation of air bubbles into the resulting molded article can be further suppressed.

[0011] [4] In the method for manufacturing the molded article described in [3] above, it is preferable that at least one of the first injection step, the second injection step, the curing step, and the pressurized degassing step be carried out using an autoclave. If at least one of the above steps is carried out using an autoclave, the manufacturing time of the molded article can be further shortened.

[0012] [5] In any of the methods for manufacturing a molded article described in [1] to [4] above, it is preferable that the molding material is mixed in a static mixer while being injected into the cavity in the first injection step and the second injection step. By injecting the molding material into the cavity while mixing it in a static mixer, the incorporation of air bubbles into the resulting molded article can be further suppressed without performing a degassing step.

[0013] [6] In any of the methods for manufacturing a molded body described in [1] to [5] above, the molded body is preferably a mold. If the molded body is a mold, various articles having features corresponding to the features of the feature-forming portion can be easily manufactured using the mold.

[0014] [7] In any of the methods for manufacturing a molded body described in [1] to [6] above, the molding tool preferably comprises a support mold and a transfer mold having the feature forming portion, and the injection port and the discharge port are provided on the support mold. By using a molding tool consisting of a support mold and a transfer mold, a molded body integrated with the support mold can be obtained. Furthermore, if the injection port and discharge port are provided on the support mold, it is possible to suppress the residue of excess cured molding material remaining on the molded body.

[0015] Furthermore, the present invention aims to advantageously solve the above problems, and the present invention is a molding apparatus comprising: [8] a cavity for housing a molding material, a feature forming section provided in a part of the cavity, and a molding tool having an inlet and an outlet for the molding material; a material container for storing the molding material; a pressurizing section for pressurizing the molding material in the material container; and a depressurizing section for depressurizing the cavity, wherein the material container is connected to the inlet of the molding tool, and the depressurizing section is connected to the outlet of the molding tool. The above molding apparatus can be suitably used in the above-described method for manufacturing a molded body.

[0016] According to the present invention, it is possible to provide a method for manufacturing a molded article that can shorten the manufacturing time of the molded article while suppressing the incorporation of air bubbles into the molded article. Furthermore, according to the present invention, it is possible to provide a molding apparatus used in the above-mentioned method for manufacturing a molded article.

[0017] This is a schematic diagram showing an example of the molding apparatus of the present invention. This is a schematic diagram showing another example of the molding apparatus of the present invention. This is a diagram for explaining the method of manufacturing a molded article according to the first embodiment of the present invention. This is a diagram for explaining the method of manufacturing a molded article according to the first embodiment of the present invention. This is a diagram for explaining the method of manufacturing a molded article according to the first embodiment of the present invention. This is a diagram for explaining the method of manufacturing a molded article according to the first embodiment of the present invention. This is a diagram for explaining the method of manufacturing a molded article according to the second embodiment of the present invention. This is a diagram for explaining the method of manufacturing a molded article according to the second embodiment of the present invention. This is a diagram for explaining the method of manufacturing a molded article according to the second embodiment of the present invention. This is a diagram for explaining the method of manufacturing a molded article according to the second embodiment of the present invention.

[0018] Embodiments of the present invention will be described in detail below. The method for manufacturing a molded article of the present invention is used for manufacturing molded articles, and the molded article manufactured by the method for manufacturing a molded article of the present invention can be suitably used as a mold for manufacturing articles having a microstructure on their surface, such as a microfluidic device. The molding apparatus of the present invention can be suitably used, for example, in the method for manufacturing a molded article of the present invention.

[0019] (Method for Manufacturing a Molded Article) The method for manufacturing a molded article of the present invention (hereinafter also simply referred to as the "manufacturing method") is characterized by using a molding tool having a cavity for containing a molding material, a feature forming section provided in a part of the cavity, and an injection port and an outlet for the molding material. The manufacturing method of the present invention is characterized by including a depressurization step of creating a depressurized state inside the cavity, a first injection step of injecting the molding material into a part of the cavity through the injection port while pressurizing it, simultaneously with or after the start of depressurization inside the cavity, a second injection step of injecting the molding material into the cavity while pressurizing it until at least the cavity is filled with the molding material, after stopping the depressurization inside the cavity, and a curing step of curing the molding material injected into the cavity after the second injection step. The manufacturing method of the present invention may optionally further include other steps other than the first injection step, the second injection step and the curing step described above.

[0020] According to the manufacturing method of the present invention, it is possible to shorten the manufacturing time of the molded article while suppressing the incorporation of air bubbles into the molded article.

[0021] <Molding Tool> As described above, the molding tool used in the manufacturing method of the present invention has a cavity for housing the molding material, a feature forming section provided in a part of the cavity, and an injection port and an outlet for the molding material.

[0022] <<Cavity>> The cavity is a space for containing the molding material, which is the raw material, and for molding it to form a molded body of a desired shape. It is the region into which the molding material is injected in the first injection step and the second injection step of the manufacturing method of the present invention.

[0023] <<Feature Forming Section>> The feature forming section is a region located within the cavity that contains features for transferring fine structures such as fine patterns to the surface or interior of the molded product being manufactured.

[0024] The feature formation area is not particularly limited and can have various dimensions and shapes depending on the application of the molded article being manufactured. The dimensions of the feature may be, for example, on a microscale, ranging from a few micrometers to several hundred micrometers. The shape of the feature is also not particularly limited and may include, for example, recesses, protrusions, grooves, projections, ribs, textures, and combinations of two or more of these. Specifically, examples of microscale features include microchannels, micropillars, microposts, microwells, and combinations of two or more of these.

[0025] The feature formation area is not limited, but may be suitable for forming various microstructures such as channel patterns in microfluidic devices, diffraction gratings in optical elements, microwell structures in biochips, and conductive patterns in electronic components.

[0026] The feature formation portion is not particularly limited and can be formed by any method. For example, the feature formation portion can be provided by processing the part that constitutes the cavity of the molding tool by machining, electrical discharge machining, photolithography, laser processing, etching, nanoimprint, etc.

[0027] <<Injection Port>> The injection port is a hole provided in the molding tool for injecting the molding material into the cavity. Specifically, the injection port is a through-hole connecting the inside and outside of the cavity. The dimensions and shape of the injection port are not particularly limited.

[0028] The placement of the injection port is not particularly limited, but from the viewpoint of further suppressing the incorporation of air bubbles into the molded product, it is preferable to place the injection port vertically lower than the discharge port (i.e., towards the ground).

[0029] <<Discharge Port>> The discharge port is a hole provided to discharge molding material, air, or other gases from the cavity to the outside of the molding tool. Specifically, the discharge port is a through-hole connecting the inside and outside of the cavity. The dimensions, shape, and position of the discharge port are not particularly limited.

[0030] <<Materials>> The molding tool is not limited to any specific material and can be constructed using any material. Examples of materials for the molding tool include resin materials and metal materials. Examples of resin materials include acrylic resin, cycloolefin polymer, polycarbonate resin, polyacetal resin, polypropylene resin, polyphenyl sulfide resin, polyimide resin, polyetherketone resin, and polytetrafluoroethylene resin. Examples of metal materials include aluminum, stainless steel, pre-hardened steel, azurolted steel, titanium, zinc, and copper. If the molding material includes a photocurable resin, at least a portion of the molding tool should be made of a transparent material such as a transparent resin to allow light to pass through for curing the photocurable resin.

[0031] <<Composition>> The molding tool is not particularly limited as long as it has the components described above, but it is preferably composed of a support mold and a transfer mold. In this case, the cavity is formed by the combination of the support mold and the transfer mold.

[0032] [Support Type] The support type is a component that forms part of the cavity and supports the transfer mold to ensure the rigidity and stability of the entire molding tool. The support type is also usually a component that is integrated with the molded body to be manufactured (i.e., a residual mold). The support type is not particularly limited and can be made from any material, for example, the resin material and metal material mentioned above. From the viewpoint of increasing the durability of the composite formed by the integration of the support type with the molded body to be manufactured, it is preferable to use a metal material such as aluminum or stainless steel.

[0033] Here, the injection port may be formed on either the support type or the transfer type, but it is preferable that it be formed on the support type. Similarly, the discharge port may be formed on either the support type or the transfer type, but it is preferable that it be formed on the support type. Furthermore, the injection port or discharge port may be provided at the boundary between the support type and the transfer type. Specifically, a part of the injection port or discharge port may be formed on the support type, the other part of the injection port or discharge port may be formed on the transfer type, and the injection port or discharge port may be formed when the support type and the transfer type are combined. If the injection port and discharge port are provided on the support type, it is possible to suppress the residue of excess cured molding material remaining in the molded body.

[0034] [Transfer mold] The transfer mold is a component that constitutes part of the cavity and has the feature-forming portion described above on the surface constituting the cavity. The transfer mold is usually positioned so that the feature-forming portion faces the support mold. When the molding material injected into the cavity hardens, the features of the feature-forming portion of the transfer mold are transferred, thereby producing a molded body with desired features (such as a fine pattern). The transfer mold is not particularly limited and can be made using any material, for example, the resin material and metal material described above. If the support mold is made of an opaque material such as a metal material and the molding material includes a photocurable resin, the transfer mold is made of a transparent material such as a transparent resin in part to allow light to pass through for curing the photocurable resin.

[0035] <Molding Material> The molding material is a liquid material used to manufacture a molded body. The molding material is not particularly limited as long as it can be injected into the cavity through an injection port and contains a material that can be cured by heat, light, pressure, etc., and various materials can be used depending on the desired application. Examples of materials used in molding materials include curable resins such as thermosetting resins and photocuring resins.

[0036] Examples of thermosetting resins include thermosetting acrylic resins, epoxy resins, phenolic resins, urethane resins, unsaturated polyester resins, and thermosetting silicone resins. Examples of photocurable resins include photocurable acrylic resins and photocurable silicone resins.

[0037] Furthermore, the molding material may optionally contain a curing agent or solvent. Examples of curing agents for thermosetting acrylic resins include organic peroxides. Examples of curing agents for epoxy resins include amine-based curing agents and acid anhydride-based curing agents. Examples of curing agents for urethane resins include isocyanate compounds. Examples of curing agents for unsaturated polyester resins include organic peroxides. Examples of curing agents for thermosetting silicone resins include organic peroxides and platinum catalysts. In addition, examples of curing agents (photoinitiators) for photocurable resins include benzoin methyl ether, acetophenone compounds, thioxanthone compounds, benzophenone compounds, and sulfonium salts.

[0038] The solvent is not particularly limited, and various organic solvents can be used.

[0039] The molding material can be prepared, for example, by mixing the curable resin described above with any curing agent and / or solvent described above in any manner. Furthermore, if the mixing is performed using a static mixer as described later (i.e., if the molding material is pre-mixed using a static mixer), the incorporation of air bubbles into the molded article can be further suppressed.

[0040] <Depressurization Process> In the depressurization process, the pressure inside the cavity of the molding tool is reduced. The depressurization process is not particularly limited, but from the viewpoint of further suppressing the incorporation of air bubbles into the molded product, it is preferable to reduce the pressure (gauge pressure) inside the cavity to -0.01 MPa or less, more preferably to -0.05 MPa or less, and even more preferably to -0.1 MPa or less. The depressurization is not particularly limited and can be performed using known vacuum devices such as vacuum pumps.

[0041] <First Injection Process> In the first injection process, the molding material is injected into a portion of the cavity through the injection port while under pressure. Pressurization may begin at the same time as the molding material begins to move toward the cavity (hereinafter referred to as the "casting start time"), or it may begin after the casting start time (for example, when the molding material has entered the cavity).

[0042] The pressure (gauge pressure) for pressurizing the molding material is not particularly limited, but is preferably 0.001 MPa or more, more preferably 0.01 MPa or more, further preferably 0.05 MPa or more, particularly preferably 0.4 MPa or more, preferably 10 MPa or less, more preferably 5 MPa or less, and further preferably 1.0 MPa or less. When the pressure for pressurizing the molding material is equal to or higher than the above lower limit, it is possible to further shorten the production time of the molded article while further suppressing the incorporation of bubbles into the molded article. In addition, when the pressure for pressurizing the molding material is equal to or lower than the above upper limit, excessive compression of the molding material can be suppressed, and the appearance of the produced molded article can be improved. During the first injection step, the pressure applied to the molding material may be constant or may vary.

[0043] The pressurization is not particularly limited, and for example, can be performed by pressurizing the molding material with compressed air supplied from an air compressor or the like connected to the container in a state where the container containing the molding material and the injection port are connected via a flow path such as a tube. Alternatively, the molding tool may be housed in an autoclave, and the molding material may be pressurized using the pressurization mechanism of the autoclave. The pressurization may be stopped after injecting a predetermined amount of the molding material into the cavity in a reduced pressure state, or may be continued for the second injection step performed after the first injection step.

[0044] Further, from the viewpoint of further suppressing the incorporation of gas into the molded article without performing a defoaming step, the molding material is preferably injected while being mixed with a static mixer. As described above, by using a static mixer, the molded article can be efficiently produced while further suppressing the incorporation of gas into the molded article.

[0045] In the first injection step, it is sufficient that a part of the cavity is filled with the molding material (that is, less than 100% of the volume of the cavity is filled with the molding material), preferably 97% or more of the volume of the cavity is filled with the molding material, more preferably 98% or more of the volume of the cavity is filled with the molding material, and even more preferably 99% or more of the volume of the cavity is filled with the molding material. If the proportion of the cavity filled with the molding material in the first injection step is equal to or higher than the above lower limit value, the incorporation of bubbles into the molded article can be further suppressed

[0046] The first injection step may be performed simultaneously with the pressure reduction step, or may be performed after the pressure reduction step. Specifically, for example, the injection of the molding material and the pressure reduction in the cavity may be started at the same time, or the molding material may be injected after the inside of the cavity is brought into a reduced pressure state. From the viewpoint of further suppressing the incorporation of bubbles into the obtained molded article, it is preferable to start the injection of the molding material after the inside of the cavity is brought into a reduced pressure state.

[0047] <Second Injection Step> In the second injection step, after stopping the pressure reduction in the cavity, the molding material is injected into the cavity while being pressurized until at least the entire cavity (that is, 100% of the volume of the cavity) is filled with the molding material. Thereby, the bubbles mixed in the molding material can be satisfactorily discharged from the discharge port.

[0048] Specifically, in the second injection step, first, the pressure reduction of the cavity is stopped, and the pressure in the cavity is increased to the atmospheric pressure. Then, the molding material is injected into the cavity while being pressurized. Here, when the pressurization in the first injection step is temporarily stopped as described above, after the pressure reduction in the cavity is stopped, the pressurization may be started after the pressure in the cavity is returned to the atmospheric pressure, but from the viewpoint of further shortening the production time, it is preferable to stop the pressure reduction of the cavity while the pressurization of the molding material in the first injection step is continued as it is. Even if the pressurization of the molding material is continued without returning the pressure in the cavity to the atmospheric pressure, as a result of the molding material continuing to be discharged from the discharge port, an unfilled portion remains in the vicinity of the discharge port, and the entire cavity is not completely filled with the molding material.

[0049] The pressure (gauge pressure) applied to the molding material is not particularly limited and can be the same as the preferred pressure in the first injection step. The pressure applied to the molding material in the second injection step may be the same as or different from the pressure in the first injection step. Furthermore, the pressure applied to the molding material during the second injection step may be constant or varied.

[0050] Pressurization is not particularly limited and can be performed in the same manner as in the first injection process. Note that if different pressurizing units (devices) are used for the first and second injection processes, there is a risk of air bubbles being introduced into the molding material when switching devices. However, by using the same pressurizing device as in the first injection process, the possibility of air bubbles being introduced into the molding material can be reduced.

[0051] Injection and pressurization may be continued even after 100% of the cavity volume has been filled with the molding material. For example, injection and pressurization may be continued until the molding material is trapped in the molding material trap described later. However, from the viewpoint of reducing the loss of molding material, it is preferable to stop when 100% of the cavity volume has been filled with the molding material. Furthermore, as with the first injection step, from the viewpoint of further suppressing the mixing of gas into the molded body, it is preferable to inject the molding material while mixing it with a static mixer.

[0052] <Curing Process> The curing process is the process of curing the molding material injected into the cavity. For example, if the molding material contains a thermosetting resin, curing can be performed by heating the molding material injected into the cavity to a predetermined temperature. The heating temperature and heating time can be set appropriately depending on the type of thermosetting resin, etc. Furthermore, heating is not particularly limited and can be performed using heating equipment such as heaters, electric ovens, and autoclaves.

[0053] Furthermore, if the molding material includes a photocurable resin, curing can be performed by irradiating the molding material injected into the cavity with ultraviolet light or visible light. The light irradiation is not particularly limited and can be performed using ultraviolet lamps, LED light sources, laser light sources, etc.

[0054] <Other steps> Other steps that may be included in the manufacturing method of the present invention are not particularly limited, but include a degassing step for degassing the molding material, a demolding step for demolding the molded body, and an additional curing step for further curing the molded body.

[0055] <<Degassing Process>> The degassing process is the process of removing bubbles from the molding material that is injected into the cavity, and is usually performed before the first injection process. By performing the degassing process, the incorporation of air bubbles into the molded body can be further suppressed.

[0056] Degassing of the molding material can be done by either pressurized degassing or reduced-pressure degassing, but pressurized degassing is preferred from the viewpoint of further suppressing the incorporation of air bubbles into the molded article.

[0057] [Pressurized Degassing] The pressure (gauge pressure) applied to the molding material when performing pressurized degassing is not particularly limited, but is preferably 0.05 MPa or higher, more preferably 0.1 MPa or higher, even more preferably 0.6 MPa or higher, preferably 10 MPa or lower, more preferably 1.5 MPa or lower, and even more preferably 1.0 MPa or lower. If the pressure of pressurized degassing is above the lower limit, the degassing time can be shortened while further suppressing the mixing of air bubbles into the molded body. If the pressure of pressurized degassing is below the upper limit, it is possible to change to a suitable pressure that can be used in the first injection step in a short time.

[0058] The pressure degassing time is not particularly limited, but is preferably 1 minute or more, more preferably 3 minutes or more, even more preferably 5 minutes or more, preferably 3 hours or less, and most preferably 30 minutes or less. If the pressure degassing time is above the lower limit, the incorporation of air bubbles into the molded article can be further suppressed. If the pressure degassing time is below the upper limit, the manufacturing time can be kept from becoming longer.

[0059] Furthermore, pressurized degassing is not particularly limited, but can be performed, for example, by pressurizing the molding material with compressed air supplied from an air compressor, or by placing a molding tool inside an autoclave and pressurizing the molding material using the autoclave's pressurizing mechanism.

[0060] [Degassing under reduced pressure] The pressure (gauge pressure) applied to the molding material when performing degassing under reduced pressure is not particularly limited, but it is preferably -0.1 MPa or less. If the pressure of degassing under reduced pressure is below the above upper limit, the degassing time can be shortened while further suppressing the incorporation of air bubbles into the molded body.

[0061] The vacuum degassing time is not particularly limited, but is preferably 5 minutes or more, more preferably 15 minutes or more, even more preferably 20 minutes or more, preferably 3 hours or less, and most preferably 60 minutes or less. If the vacuum degassing time is above the lower limit, the incorporation of air bubbles into the molded article can be further suppressed. If the vacuum degassing time is below the upper limit, the manufacturing time can be kept from becoming longer.

[0062] Furthermore, vacuum degassing is not particularly limited and can be performed by reducing the pressure of the molding material in a vacuum chamber or other vacuum device.

[0063] <<Demolding Process>> In the demolding process, the molded body obtained after the curing process is demolded by any known method. As mentioned above, when the molding tool consists of a transfer mold and a support mold, the molded body is usually integrated with the support mold, so demolding is performed by peeling the composite (integrated structure) consisting of the molded body and the support mold from the transfer mold.

[0064] <<Additional Hardening Process>> The additional hardening process is a process (post-hardening process) that further hardens the molded body obtained in the above hardening process. By performing the additional hardening process, the parts that were not hardened in the above hardening process are hardened, which can further improve the physical properties of the molded body and enhance the dimensional stability of the molded body.

[0065] The additional curing step may be performed immediately after the curing step or after the demolding step, but it is preferable to perform it after the demolding step. The additional curing step can be performed in the same manner as the curing step. The type and conditions of curing in the additional curing step may be the same as or different from those of the curing step.

[0066] <Apparatus for performing injection, pressure degassing, and curing processes> It is preferable that at least one of the above-mentioned first injection process, second injection process, pressure degassing process, and curing process be performed using an autoclave. Specifically, for example, the molding apparatus (excluding the vacuum section) described later can be housed inside the autoclave, and the above processes can be performed by operating the pressurizing mechanism and heating mechanism of the autoclave. Since these processes can be easily performed using an autoclave, the manufacturing time can be further shortened. From the viewpoint of further shortening the manufacturing time, it is more preferable to perform the pressure degassing process, the first injection process, and the second injection process using an autoclave, and it is even more preferable to perform all of the first injection process, the second injection process, the pressure degassing process, and the curing process using an autoclave. In this way, since these processes can be performed automatically and continuously by using an autoclave, molded articles can be manufactured efficiently.

[0067] <Molded Article> In a molded article manufactured by the manufacturing method of the present invention, features corresponding to the features of the feature-forming part of the molding tool are transferred to its surface or interior. For example, when the molding tool consists of a support mold and a transfer mold, a cured product (molded article) of the molding material having predetermined features is usually formed on the support mold. The molded article is not particularly limited, but it is preferably a mold. If the molded article is used as a mold, articles having microstructures such as housings and micro-components of electrical products, optical lenses, and microfluidic devices can be easily obtained. Furthermore, the mold is not particularly limited and can be used, for example, for thermal embossing, injection molding, compression molding, and combinations thereof or deformation.

[0068] (Molding apparatus) The molding apparatus of the present invention comprises a molding tool having a cavity for containing a molding material, a feature forming section provided in a part of the cavity, and an injection port and an outlet for the molding material, a material container for storing the molding material, a pressurizing section for pressurizing the molding material in the material container, and a depressurizing section for depressurizing the cavity, and optionally includes other components other than the molding tool, the material container, the pressurizing section and the depressurizing section. The molding apparatus of the present invention can be suitably used in the method for manufacturing a molded article of the present invention described above.

[0069] <Molding Tools> The molding tools described above in the section "Method for Manufacturing Molded Articles" can be used.

[0070] <Material Container> The material container is a container for storing the molding material supplied to the cavity of the molding tool, and is connected to the inlet of the molding tool. The material container may also be connected to a pressurizing unit. The material container usually has an opening for filling the container with molding material and an outlet for discharging the molding material out of the container. The material container is not particularly limited, but examples include syringes. In the case of using the static mixer described above, the cartridge attached to the static mixer functions as the material container.

[0071] <Pressurization Section> The pressurization section is a component for pressurizing the molding material contained in the material container. The pressurization section can also function as a component for pressurizing the molding material into the cavity of the molding tool. The pressurization section is not particularly limited, but an air compressor, autoclave, etc., can be used. The pressurization section can be connected to the material container. When an autoclave is used as the pressurization section, the pressurization section can also function as a device for pressurizing and degassing the molding material, or as a device for curing the molding material. The material container, molding tool, and molding material trap, which will be described later, can be housed inside the autoclave.

[0072] <Depressurization Section> The depressurization section is a component for creating a depressurized state inside the cavity of the molding tool and is connected to the discharge port of the molding tool. The depressurization section is not particularly limited, but known depressurization devices such as vacuum pumps can be used.

[0073] <Other Components> Other components that the molding apparatus of the present invention may have include: flow paths between components (such as tubes and hoses); a molding material trap; connecting fittings for sealing the inlet and outlet with the flow paths; a cock for controlling the fluid flow; and a gauge for measuring pressure. Here, the molding material trap has the function of storing the molding material that flows out from the outlet in the first and second injection steps, and preventing the molding material from reaching the depressurized section while enabling depressurization in the cavity. The molding material trap is usually provided between the molding tool and the depressurized section and may be connected to the outlet and depressurized section of the molding tool.

[0074] <Example of a Molding Apparatus> An example of a molding apparatus of the present invention will be described below with reference to the drawings. Figure 1 is a schematic diagram showing an example of a molding apparatus of the present invention. Referring to Figure 1, the molding apparatus 1 comprises, as its main components, a molding tool 10, a material container 20, a pressurizing section 30, a depressurizing section 40, and a molding material trap 50. In Figure 1, the molding tool 10 is shown in a cross-sectional view so that its interior is visible.

[0075] The molding tool 10 consists of a transfer mold 10a and a support mold 10b. The transfer mold 10a is combined with the support mold 10b such that the feature forming section 11 faces the support mold 10b. The transfer mold 10a and the support mold 10b form a cavity 14. Connecting fittings 60 are attached to the inlet 12 and outlet 13 of the support mold 10b, and the inlet 12 is located vertically lower (towards the ground) than the outlet 13. The molding material 21 is contained in the material container 20, and the lower part of the material container 20 is connected to the inlet 12 of the support mold 10b via the connecting fittings 60 and the flow path 70. The pressurizing section 30 is connected to the upper part of the material container 20 via the flow path 70. The depressurizing section 40 is connected to the molding material trap 50 via the flow path 70. The molding material trap 50 is connected to the discharge port 13 of the support type 10b via a flow path 70 and a connecting joint 60. A cock 80 is provided in the flow path 70 between the pressurizing section 30 and the material container 20, and cocks 81 to 83 are provided in the flow path 70 between the depressurizing section 40 and the molding material trap 50, respectively. The ends of the flow path 70 to which cocks 80, 81, and 83 are provided, that are not connected to the respective devices, are connected to the outside of the device (atmospheric pressure).

[0076] Figure 2 is a schematic diagram showing another example of the molding apparatus of the present invention. The same components and configurations as in Figure 1 will not be described. The molding apparatus 1 shown in Figure 2 is an example in which the pressurizing section 30 is configured as an autoclave. As shown in Figure 2, all components except the depressurizing section 40, the cocks 81-83, and the flow path 70 between the depressurizing section 40 and the molding material trap 50 are housed within the autoclave, which serves as the pressurizing section 30. Furthermore, instead of the cock 80 in Figure 1, a cock 84 is provided in the flow path 70 between the material container 20 and the molding tool 10.

[0077] <First Embodiment> The manufacturing method according to the first embodiment of the present invention will be described below with reference to Figures 3A to 3D. In the first embodiment, a molded body is manufactured using the molding apparatus 1 shown in Figure 1. First, with the valves 80, 81, and 83 closed and valve 82 open, the depressurization unit 40 and the pressurization unit 30 are activated. This creates a depressurized state inside the cavity 14 while pressurizing the molding material 21 in the material container 20, and as shown in Figure 3A, the injection of the molding material 21 contained in the material container 20 into the cavity 14 is started. Then, as shown in Figure 3B, a portion of the cavity 14 is filled with the molding material 21 containing air bubbles 21a, leaving an unfilled portion 14a. Next, with valve 82 closed, valves 81 and 83 are opened, and the operation of the depressurization unit 40 is stopped, thereby stopping the depressurization inside the cavity 14. This allows the air bubbles 21a in the molding material 21 to be discharged from the outlet 13, while the unfilled portion 14a is filled with the molding material 21, as shown in Figure 3C. Then, once the entire cavity 14 is filled with the molding material 21, the operation of the pressurizing unit 30 is stopped and the cock 80 is opened. As shown in Figure 3C, the molding material trap 50 stores the excess molding material 21 discharged from the discharge port 13. Next, as shown in Figure 3D, the molding tool 10 is removed from the molding apparatus 1. Then, the curing process of the molding material 21 is performed, and the composite of the cured molding material 21 (molded body) and the support mold 10b is demolded from the transfer mold 10a. An article is then manufactured using this composite. For example, an article can be manufactured by manufacturing two composites having two different characteristics (such as fine patterns) and molding them with resin sandwiched between the two composites. Alternatively, an article can be manufactured by molding them with resin sandwiched between a composite having a fine pattern and a composite without a fine pattern.

[0078] <Second Embodiment> The manufacturing method according to the second embodiment of the present invention will be described below with reference to Figures 4A to 4E. In the second embodiment, a molded body is manufactured using the molding apparatus 1 shown in Figure 2. In the second embodiment, the molding material 21 is degassed under pressure prior to the first injection step. Figure 4A shows the state in which the molding material 21 contained in the material container 20 is being pressurized in an autoclave as the pressurizing unit 30. First, all the cocks 81 to 84 are closed and the depressurizing unit 40 is stopped, and the pressurizing mechanism of the autoclave is activated to pressurize the molding material 21 in the material container 20 and degas the molding material 21. Next, cock 82 is opened and the depressurizing unit 40 is activated to create a depressurized state inside the cavity 14. Then, cock 84 is opened and, as shown in Figure 4B, the injection of the pressurized molding material 21 into the cavity 14 is started. Then, as shown in Figure 4C, a part of the cavity 14 is filled with molding material 21 containing air bubbles 21a, leaving an unfilled portion 14a. Next, the valve 82 is closed to stop the operation of the depressurization unit 40, and the valves 81 and 83 are opened to stop the depressurization in the cavity 14. As a result, as shown in Figure 4D, air bubbles 21a in the molding material 21 are discharged from the outlet 13, while the unfilled portion 14a is filled with the molding material 21. Once the entire cavity 14 is filled with the molding material 21, the operation of the pressurization unit 30 is stopped. By stopping the pressurization of the pressurization unit 30, the inside of the autoclave becomes atmospheric pressure. As shown in Figure 4D, the molding material trap 50 stores the excess molding material 21 discharged from the outlet 13 of the molding tool 10. Next, the heating mechanism of the autoclave is activated to heat under predetermined conditions and perform the curing process of the molding material 21. Then, as shown in Figure 4E, the molding tool 10 is removed from the molding apparatus 1, and the composite of the cured molding material 21 (molded body) and the support mold 10b is demolded from the transfer mold 10a. Articles are then manufactured using these composites. For example, articles can be manufactured by separately producing composites with two different characteristics (such as fine patterns) and then molding them with resin sandwiched between them. Alternatively, articles can be manufactured by, for example, sandwiching resin between a composite with a fine pattern and a composite without a fine pattern and then molding them.

[0079] The present invention will be described in detail below based on examples, but the present invention is not limited to these examples. Various measurements and evaluations in the examples and comparative examples were performed by the following methods.

[0080] <Inclusion of air bubbles in the molded body> The molded bodies produced in the examples and comparative examples were observed, and the number of air bubbles that could be visually confirmed was measured and evaluated based on the following criteria. The fewer the number of air bubbles, the more effectively the inclusion of air bubbles in the molded body is suppressed. A: 0 bubbles B: 1 to 5 bubbles C: 6 to 9 bubbles D: 10 or more bubbles <Coverage rate of molding tool> The areas of the support mold used in the examples and comparative examples that were covered with the molding material were photographed with a camera, and the coverage rate of the molding tool was calculated using the following formula. It was then evaluated based on the following criteria. Coverage rate of molding tool (%) = [Area covered by the molding material of the support mold / Area of ​​the area of ​​the support mold that should be covered by the resin] × 100 A: Coverage rate of 100% B: Coverage rate of 99% or more and less than 100% C: Coverage rate of less than 99% <Appearance of molded body> The appearance of the molded bodies produced in the examples and comparative examples was evaluated based on the following criteria. A: No strain (variation in in-plane thickness of molded body is within Δ100um) B: Slight strain (variation in in-plane thickness of molded body is greater than Δ100um but within Δ200um) C: Strain is too great to use (variation in in-plane thickness of molded body is greater than Δ200um) Here, the in-plane thickness of the molded body was measured using a contact-type film thickness gauge (product surface "VL-50S-B", manufactured by Mitutoyo Corporation). The variation in in-plane thickness of the molded body is the difference between the minimum and maximum values ​​of the measured in-plane thickness of the molded body. <Manufacturing time of molded body> A: Manufacturing time is 10 minutes or more faster than Example 1 B: Manufacturing time is less than ±10 minutes of the manufacturing time of Example 1 C: Manufacturing time is 10 minutes or more but less than 60 minutes longer than the manufacturing time of Example 1 D: Manufacturing time is 60 minutes or more longer than the manufacturing time of Example 1

[0081] (Example 1) <Preparation of molding material> The main component and hardener of the molding material were weighed into a cup in a mass ratio of 10:1 and mixed with a spatula.

[0082] <Degassing under reduced pressure> After mixing, the molding material in the cup was degassed under reduced pressure in a vacuum chamber at a gauge pressure of -0.1 MPa for 15 minutes. After 15 minutes of degassing, the molding material in the cup was transferred to a syringe to be used as a material container. The syringe was then degassed under reduced pressure in a vacuum chamber at a gauge pressure of -0.1 MPa for 15 minutes.

[0083] <Assembly of the molding apparatus> A molding apparatus similar to molding apparatus 1 shown in Figure 1 was assembled. Specifically, an adapter tube connected to an air line connected to a compressed air supply source was connected to the flange of the syringe. A tube fitting as a connecting joint was attached to the inlet of the molding tool (size: 20 cm x 20 cm), and the tip of the syringe and the inlet were connected with a hose. In addition, a tube fitting as a connecting joint was attached to the outlet of the molding tool, and the molding material trap and the outlet were connected with a hose. Furthermore, a vacuum pump as a depressurization unit and the molding material trap were connected with a hose.

[0084] <Manufacturing of Molded Body> The vacuum pump was turned ON to reduce the pressure inside the cavity of the molding tool to -0.1 MPaG. Compressed air was supplied from an air line connected to a compressed air supply source to start pressurizing the molding material at 0.4 MPaG, and a portion of the cavity (99% to less than 100% of the cavity volume) was filled with the molding material (first injection step). Next, while continuing to pressurize, the vacuum pump was turned OFF to stop the pressure reduction inside the cavity, and when the entire cavity (100% of the cavity volume) was filled with the molding material, pressurization was stopped (second injection step). Next, the molding tool into which the molding material had been injected was cured using an electric oven at a curing temperature and time that allowed for demolding (80°C, 1 hour) (curing step). Next, the composite of the cured product and the support mold was demolded from the transfer mold (demolition step). Finally, this composite was further cured using an electric oven at a curing temperature of 200°C for 2 hours (additional curing step). Through the above process, a molded body with the characteristics of the transfer type was manufactured. The manufacturing time for the molded body (from mixing the main agent and hardener to immediately before the curing process) was 1 hour. Various measurements and evaluations were then performed on the molded body. The results are shown in Table 1.

[0085] (Example 2) A molded body was manufactured in the same manner as in Example 1, except that the molding tool was changed to a molding tool with a size of 5 cm x 5 cm and having a different feature-forming part than that of Example 1. Various measurements and evaluations were then performed on the molded body. The results are shown in Table 1.

[0086] (Examples 3-6) Molded bodies were manufactured in the same manner as in Example 1, except that the pressure inside the cavity under reduced pressure was changed as shown in Table 1 during the first injection process. Various measurements and evaluations were then performed on the molded bodies. The results are shown in Table 1.

[0087] (Examples 7-16) Molded bodies were manufactured in the same manner as in Example 1, except that the pressure applied to the molding material in the first and second injection steps was changed as shown in Table 1. Various measurements and evaluations were then performed on the molded bodies. The results are shown in Tables 1 and 2.

[0088] (Examples 17-18) Molded bodies were manufactured in the same manner as in Example 1, except that the proportion of the cavity volume filled with molding material in the first injection step was changed as shown in Table 1. Various measurements and evaluations were then performed on the molded bodies. The results are shown in Table 2.

[0089] (Example 19) A molded body was manufactured in the same manner as in Example 1, except that the molding tool 10 was inverted and its configuration was changed so that the discharge port was located vertically lower (towards the ground) than the injection port. Various measurements and evaluations were then performed on the molded body. The results are shown in Table 2.

[0090] (Example 20) <Preparation of molding material> The main component and hardener of the molding material were weighed into a cup in a mass ratio of 10:1 and mixed with a spatula. After mixing, the molding material was transferred from the cup to a syringe.

[0091] <Assembly of the Molding Apparatus> A molding apparatus similar to molding apparatus 1 shown in Figure 2 was assembled. Specifically, a tube fitting as a connecting joint was attached to the injection port of the molding tool, and the tip of the syringe and the injection port were connected by a hose. In addition, a tube fitting as a connecting joint was attached to the discharge port of the molding tool, and the molding material trap and the discharge port were connected by a hose. Furthermore, a vacuum pump as a depressurization unit and the molding material trap were connected by a hose. The entire assembly from the syringe to the molding material trap was placed inside the autoclave, and the molding material trap and vacuum pump were connected to dedicated piping inside the autoclave. The autoclave was started, and the molding material in the syringe was pressurized and degassed under conditions of 0.8 MPaG for 5 minutes (degassing process). Next, the vacuum pump was turned ON to reduce the pressure inside the cavity (-0.1 MPaG), and then the cock between the syringe and the molding tool (cock 84 in Figure 2) was opened to maintain pressurization at 0.8 MPaG. This initiated the injection of the molding material into the cavity from the injection port, filling a portion of the cavity (99% to less than 100% of the cavity's volume) with the molding material (first injection step). Next, while maintaining pressurization, the vacuum pump was turned off to stop the depressurization inside the cavity, filling the entire cavity (100% of the cavity's volume) with the molding material, and pressurization was terminated (second injection step). The molding material, into which the molding material had been injected, was cured in the autoclave at a curing temperature and time (80°C, 1 hour) that allowed for demolding (curing step). Next, the above assembly was removed from the autoclave, and the composite of the cured product and the support mold was demolded from the transfer mold (demolition step). Then, this composite was further cured in an electric oven at a curing temperature of 200°C for 2 hours (additional curing step). Through the above steps, a molded body with the characteristics of the transfer mold transferred was manufactured. Various measurements and evaluations were then performed on the molded body. The results are shown in Table 2.

[0092] (Examples 21-34) Molded articles were manufactured in the same manner as in Example 20, except that the time and / or pressure for degassing the molding material under pressure was changed as shown in Tables 3 and 4. Various measurements and evaluations were then performed on the molded articles. The results are shown in Tables 3 and 4.

[0093] (Example 35) <Preparation of molding material> The main component and hardener of the molding material were weighed into a cup in a mass ratio of 10:1 and mixed with a spatula. After mixing, the molding material was transferred from the cup to a syringe.

[0094] <Degassing Process> The tip of the syringe was capped, and pressure degassing was performed in an autoclave at 0.8 MPaG for 5 minutes.

[0095] <Manufacturing of Molded Articles> Molded articles were manufactured in the same manner as in Example 1, except that the molding material subjected to the degassing process described above was used. Various measurements and evaluations were then performed on the molded articles. The results are shown in Table 4.

[0096] (Example 36) <Preparation of molding material> The main component and hardener of the molding material were weighed into a cup in a mass ratio of 10:1 and mixed with a spatula. After mixing, the molding material was transferred from the cup to a syringe.

[0097] <Assembly of the molding apparatus> A molding apparatus similar to molding apparatus 1 shown in Figure 2 was assembled. Specifically, a tube fitting was attached as a connecting joint to the injection port of the molding tool, and the tip of the syringe and the injection port were connected with a hose. In addition, a tube fitting was attached as a connecting joint to the discharge port of the molding tool, and the molding material trap and the discharge port were connected with a hose. Furthermore, a vacuum pump, which serves as a pressure reduction unit, and the molding material trap were connected with a hose. The entire assembly from the syringe to the molding material trap was placed inside the autoclave, and the molding material trap and vacuum pump were connected to dedicated piping inside the autoclave.

[0098] <Manufacturing of Molded Body> The autoclave was started and the molding material in the syringe was degassed under pressure at 0.8 MPaG for 5 minutes (degassing step). Next, the vacuum pump was turned ON to reduce the pressure inside the cavity (-0.1 MPaG), and then the stopcock between the syringe and the molding tool (stopcock 84 in Figure 2) was opened to maintain pressure at 0.8 MPaG. This initiated the injection of the molding material into the cavity from the inlet, filling a portion of the cavity (99% to less than 100% of the cavity volume) with the molding material (first injection step). Next, while continuing to apply pressure, the vacuum pump was turned OFF to stop the pressure reduction inside the cavity, filling the entire cavity (100% of the cavity volume) with the molding material, and the pressurization was terminated (second injection step). Next, the molding tool into which the molding material had been injected was removed from the autoclave, and the molding material was cured using an electric oven at a demoldable curing temperature and time (80°C, 1 hour) (curing step). Next, the composite of the cured material and the support mold was demolded from the transfer mold (demolition step). Then, this composite was further cured in an electric oven at a curing temperature of 200°C for 2 hours (additional curing step). Through these steps, a molded body with the characteristics of the transfer mold transferred onto it was produced. Various measurements and evaluations were then performed on the molded body. The results are shown in Table 4.

[0099] (Example 37) <Assembly of the molding apparatus> One end of the air line was connected to the rear side of the air gun type static mixer, and the other end of the air line was connected to a compressed air supply source. A cartridge filled with the main component and hardener of the molding material was set in the air gun type static mixer, and the mixer was attached to it. A tube fitting as a connecting joint was attached to the inlet of the molding tool (size: 20 cm x 20 cm), and the tip of the mixer and the inlet were connected with a hose. In addition, a tube fitting as a connecting joint was attached to the outlet of the molding tool, and the molding material trap and the outlet were connected with a hose. Furthermore, a vacuum pump as a depressurization unit and the molding material trap were connected with a hose.

[0100] <Manufacturing of Molded Body> The vacuum pump was turned ON to reduce the pressure inside the cavity of the molding tool to -0.1 MPaG. Then, the static mixer was operated to mix the molding material, and compressed air was supplied from the air line to start pressurizing the molding material at 0.4 MPaG. The molding material was injected from the injection port, and a portion of the cavity (more than 99% but less than 100% of the cavity volume) was filled with the molding material (first injection step). Then, while continuing to pressurize, the vacuum pump was turned OFF to stop the pressure reduction inside the cavity, and when the entire cavity (100% of the cavity volume) was filled with the molding material, pressurization was stopped (second injection step). Next, the molding tool into which the molding material had been injected was cured using an electric oven at a curing temperature and time that allowed for demolding (80°C, 1 hour) (curing step). Next, the composite of the cured product and the support mold was demolded from the transfer mold (demolition step). Then, this composite was further cured in an electric oven at a curing temperature of 200°C for 2 hours (additional curing step). Through the above process, a molded body with the characteristics of the transfer mold was produced. Various measurements and evaluations were then performed on the molded body. The results are shown in Table 4.

[0101] (Comparative Example 1) A molded body was manufactured in the same manner as in Example 1, except that the molding material was not injected under pressure during the second injection step. Various measurements and evaluations were then performed on the molded body. The results are shown in Table 4.

[0102] (Comparative Example 2) A molded body was manufactured in the same manner as in Example 1, except that no pressurization was performed in the first injection step and the molding material was not injected under pressure in the second injection step. Various measurements and evaluations were then performed on the molded body. The results are shown in Table 4.

[0103] (Comparative Example 3) A molded body was manufactured in the same manner as in Example 1, except that the pressure inside the cavity was not reduced in the first injection step. Various measurements and evaluations were then performed on the molded body. The results are shown in Table 4.

[0104] As shown in Tables 1 to 4, in Examples 1 to 37, when manufacturing a molded body using a predetermined molding tool, the molding material is injected under pressure into a portion of the cavity while the cavity is under reduced pressure, and then, with the pressure reduction of the cavity stopped, the molding material is injected under pressure into the cavity until the cavity is filled with the molding material. This shows that the manufacturing time of the molded body can be shortened while suppressing the incorporation of air bubbles into the molded body.

[0105] According to the present invention, it is possible to provide a method for manufacturing a molded article that can shorten the manufacturing time of the molded article while suppressing the incorporation of air bubbles into the molded article. Furthermore, according to the present invention, it is possible to provide a molding apparatus used in the above-mentioned method for manufacturing a molded article.

[0106] 1. Molding apparatus 10. Molding tool 10a. Transfer mold 10b. Support mold 11. Feature forming section 12. Inlet 13. Outlet 14. Cavity 14a. Unfilled section 20. Material container 21. Molding material 21a. Air bubbles 30. Pressurized section 40. Reduced pressure section 50. Molding material trap 60. Connecting fitting 70. Flow path 80-84. Cock

Claims

1. A method for manufacturing a molded article using a molding tool having a cavity for containing a molding material, a feature forming section provided in a part of the cavity, and an injection port and an outlet for the molding material, comprising: a depressurization step of reducing the pressure inside the cavity; a first injection step of injecting the molding material under pressure into a part of the cavity through the injection port, simultaneously with or after the start of depressurization inside the cavity; a second injection step of injecting the molding material under pressure into the cavity until at least the cavity is filled with the molding material, after stopping the depressurization inside the cavity; and a curing step of curing the molding material injected into the cavity after the second injection step.

2. The method for manufacturing a molded article according to claim 1, wherein the injection port is located vertically below the discharge port.

3. The method for manufacturing a molded article according to claim 1, further comprising a pressure degassing step of pressurizing and degassing the molding material before the first injection step.

4. The method for manufacturing a molded article according to claim 3, wherein at least one of the first injection step, the second injection step, the curing step, and the pressurized degassing step is performed using an autoclave.

5. The method for manufacturing a molded article according to claim 1, wherein in the first injection step and the second injection step, the molding material is injected into the cavity while being mixed with a static mixer.

6. The method for manufacturing a molded article according to claim 1, wherein the molded article is a mold.

7. The method for manufacturing a molded article according to any one of claims 1 to 6, wherein the molding tool comprises a support mold and a transfer mold having the feature forming portion, and the injection port and the discharge port are provided on the support mold.

8. A molding apparatus comprising: a cavity for containing a molding material; a feature forming section provided in a part of the cavity; and a molding tool having an inlet and an outlet for the molding material; a material container for storing the molding material; a pressurizing section for pressurizing the molding material in the material container; and a depressurizing section for depressurizing the cavity, wherein the material container is connected to the inlet of the molding tool, and the depressurizing section is connected to the outlet of the molding tool.

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