Method of producing a shaped article and manufacturing system

Abstract

A method for producing a molded article and a manufacturing system are provided. The method for producing a molded article is characterized by having: a first step of shaping a material including a cellulose derivative into a shaped body; and a second step of producing a molded article by subjecting the shaped body produced in the first step to temperature control for a predetermined time t in a predetermined temperature range, the temperature range in the second step being A-10°C or higher and A+50°C or lower when a phase transition point of the shaped body is set to A°C.

Description

Technical Field

[0001] This invention relates to a method and manufacturing system for producing molded articles. Background Technology

[0002] Cellulose derivatives are renewable resources and are biocompatible, biodegradable, and environmentally friendly materials, thus attracting considerable attention in recent years. Furthermore, the technique of injection molding raw materials containing cellulose derivatives to obtain molded articles has garnered particular interest (see, for example, Patent Document 1).

[0003] However, while injection molding of raw materials containing cellulose derivatives is environmentally friendly, it suffers from problems such as insufficient heat resistance and strength.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2018-059125 Summary of the Invention

[0005] The method for producing a molded article according to an application example of the present invention includes: a first step of molding a material comprising a cellulose derivative into a molded body; and a second step of processing the molded body generated in the first step to maintain it in a predetermined temperature range for a predetermined time t to produce a molded article, wherein when the phase transition point of the molded body is set to A℃, the temperature range in the second step is above A-10℃ and below A+50℃.

[0006] The manufacturing system involved in the application example of the present invention includes: a molding machine that shapes a material including a cellulose derivative into a molded body; a heat preservation chamber that processes the molded body formed by the molding machine to maintain it in a predetermined temperature range for a predetermined time t; and a conveyor that conveys the molded body from the molding machine to the heat preservation chamber, wherein when the phase transition point of the molded body is set to A℃, the temperature range is A-10℃ or higher and A+50℃ or lower. Attached Figure Description

[0007] Figure 1 A diagram illustrating a manufacturing system for performing a method of producing a molded article according to an embodiment of the present invention.

[0008] Figure 2 A graph showing the change in heat absorption of the molded body over time in the second step.

[0009] Figure 3 This is a flowchart illustrating an example of a method for producing molded articles according to the present invention.

[0010] Figure 4 A table summarizing the manufacturing conditions and evaluation results for each embodiment and comparative example. Detailed Implementation

[0011] The method and manufacturing system for producing molded articles according to the present invention will be described in detail below based on the preferred embodiments shown in the accompanying drawings.

[0012] Implementation Figure 1 A diagram illustrating a manufacturing system for performing a method of producing a molded article according to an embodiment of the present invention. Figure 2 A graph showing the change in heat absorption of the molded body over time in the second step. Figure 3 This is a flowchart illustrating an example of a method for producing molded articles according to the present invention. Figure 4 A table summarizing the manufacturing conditions and evaluation results for each embodiment and comparative example.

[0013] Manufacturing systems and methods for producing shaped products like Figure 1 As shown, manufacturing system 1 is an example apparatus for performing the method of producing molded articles according to the present invention, and includes a forming unit 2 (forming machine), a conveying unit 3 (conveyor), a heat preservation chamber 4, and a control unit (not shown). The forming unit 2, the conveying unit 3, and the heat preservation chamber 4 are controlled by the control unit (not shown). Furthermore, manufacturing system 1 sequentially performs a forming process (first step), a conveying process, and a processing process (second step).

[0014] Alternatively, the present invention can be applied to a manufacturing system in which the forming section 2, the conveying section 3, the heat preservation chamber 4, and the control section (not shown) are all separate devices, and these devices are connected to form a single system. Furthermore, the present invention can also be applied to a molded body manufacturing system that does not have the conveying section 3 and the heat preservation chamber 4, but consists of the forming section 2 and the control section.

[0015] The following is a detailed description of each part and process.

[0016] (1) Forming section and forming process like Figure 1 As shown, molding section 2 is the part that injection molds a material M1 containing a cellulose derivative to produce a molded body M2 (molded article M3). Molding section 2 can also be a known injection molding machine. Molding section 2 has an injection unit 21 and a mold closing unit 22. The material M1 will be described in detail later.

[0017] (1-1) Structure of the forming part The injection unit 21 has a hopper 211 and a cylinder 212. The hopper 211 is the part that supplies material M1 to the cylinder 212. The form of the material M1 supplied to the cylinder 212 is not particularly limited, and examples include powder, cotton, etc.

[0018] The cylinder body 212 has an outer cylinder 213 connected to a hopper 211, a screw 214 rotating inside the outer cylinder 213, a motor 215 that rotates the screw 214, and a heater 216 that heats the inside of the outer cylinder 213. The motor 215 and the heater 216 are electrically connected to a control unit (not shown) to control their operation.

[0019] Material M1, supplied to cylinder 212 via hopper 211, is plasticized by heating with heater 216. The plasticized material M1 is then extruded from opening 217 of outer cylinder 213 by the rotation of screw 214.

[0020] The mold-closing unit 22 has a fixed mold 221 and a movable mold 222. With the fixed mold 221 and the movable mold 222 assembled, a cavity 223 is formed between them. Plasticized material M1 flows into the cavity 223. Then, the flowing material M1 is pressurized and cooled between the fixed mold 221 and the movable mold 222. As a result, the material M1 within the cavity 223 solidifies to produce a molded body M2 (a one-piece molded body).

[0021] The fixed mold 221 and the movable mold 222 can also be structures with internal flow channels. In this case, cooling can be achieved by allowing the refrigerant to flow down in the flow channels.

[0022] When removing the molded body M2 from the cavity 223, the movable mold 222 is separated from the fixed mold 221. The method of separating the movable mold 222 from the fixed mold 221 is not particularly limited, and methods such as manual operation by an operator and connecting a moving mechanism (not shown) to the movable mold 222 and controlling its operation through a control unit are also included.

[0023] The temperature of the plasticized material M1, i.e., the temperature of the material M1 supplied from the injection unit 21 to the mold closing unit 22, is not particularly limited, but is set to a temperature higher than the phase transition point (the temperature at which the morphology changes). For example, it is preferably 180°C or higher and 350°C or lower, and more preferably 200°C or higher and 340°C or lower. As a result, the material M1 can be plasticized more effectively, thereby enabling better and smoother supply of the material M1 into the cavity 223.

[0024] The cooling temperature of the molded body M2, i.e., the temperature at which the molded body M2 is removed from the mold closing unit 22, is not particularly limited, but is set to a temperature lower than the phase transition point. For example, it is preferably 50°C or higher and 250°C or lower, and more preferably 70°C or higher and 200°C or lower. As a result, the heat resistance and strength of the molded body M2 can be improved more effectively.

[0025] Cooling of the molded body M2 can also be omitted. That is, it can also be a structure in which the molded body M2 is placed in the mold closing unit 22 after molding, and the mold closing unit 22 is immediately transported to the heat preservation chamber 4 for processing.

[0026] (1-2) Material M1 Material M1 contains cellulose derivatives.

[0027] Cellulose derivatives are compounds that can be derived from cellulose through chemical reactions. Cellulose derivatives are lightweight and have excellent strength, as well as excellent biocompatibility, biodegradability, and environmental friendliness.

[0028] Examples of cellulose derivatives include cellulose ethers, cellulose esters, and their sodium, potassium, and other alkali metal salts and ammonium salts. Among these, cellulose esters are preferred.

[0029] Cellulose ethers include, for example, one or more selected from carboxymethyl cellulose, carboxyethyl cellulose, carboxymethyl ethyl cellulose, and their sodium and potassium salts, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, ethyl cellulose, methoxymethyl cellulose, benzyl cellulose, mixtures and copolymers thereof.

[0030] Examples of cellulose esters include organic esters such as cellulose acetate, cellulose propionate, and cellulose butyrate; mixed esters such as cellulose acetate propionate and cellulose acetate butyrate; grafts such as polycaprolactone-grafted cellulose acetate; and inorganic esters such as cellulose nitrate, cellulose sulfate, and cellulose phosphate.

[0031] Cellulose esters with an acyl substitution degree of 2.7 or less are also called incompletely substituted cellulose esters. Moreover, compared with cellulose esters with an acyl substitution degree of more than 2.7, incompletely substituted cellulose esters are preferred as material M1. As a result, the heat resistance and strength of the molded body M2 can be improved more effectively during the processing steps described later.

[0032] The degree of polymerization (viscosity-uniform polymerization degree) of the cellulose ester is not particularly limited, but is preferably 200 or more and 400 or less, more preferably 210 or more and 390 or less. Therefore, the heat resistance and strength of the molded article M2 can be improved more effectively during the processing steps described later.

[0033] Furthermore, the average molecular weight of the cellulose derivative is preferably 1,000 to 1,000,000, more preferably 5,000 to 100,000. Therefore, the heat resistance and strength of the molded article M3 can be improved more effectively during the processing steps described later.

[0034] The average molecular weight can be determined by the GPC method (gel permeation chromatography) using polyethylene oxide as a standard.

[0035] The content of cellulose derivatives in material M1 is not particularly limited, but is preferably 80% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 99% by mass or less. This ensures that the content of cellulose derivatives is adequately guaranteed.

[0036] In addition to cellulose derivatives, material M1 may also contain other components such as cellulose that has not been substituted as described above (unreacted cellulose), plasticizers, flame retardants, etc.

[0037] The content of other components in material M1 is not particularly limited; for example, it is preferably 0% by mass or more and 20% by mass or less, more preferably 1% by mass or more and 10% by mass or less. This ensures that the content of cellulose derivatives is adequately guaranteed.

[0038] (1-3) Molded body M2 The shape of the molded body M2 is not particularly limited. The article obtained by melting and molding material M1 is the molded body M2 mentioned in this application.

[0039] (2) Conveying section and conveying process like Figure 1 As shown, the conveying unit 3 has the function of conveying the molded body M2 taken from the mold clamping unit 22 to the heat preservation chamber 4. Examples of conveying units 3 include robots with hands, structures with conveyor belts, and combinations thereof. Furthermore, the mold clamping unit 22 can be detached from the injection unit 21 along with the mold clamping unit 22, and the mold clamping unit 22 containing the molded body M2 can be conveyed. The conveying unit 3 is electrically connected to a control unit (not shown) to control its operation. During this conveying process, the molded body M2 can be cooled to room temperature or conveyed while maintaining a temperature above that maintained by the heat preservation chamber 4.

[0040] Alternatively, the conveying unit 3 can be omitted. For example, the operator can manually remove the molded body M2 from the mold clamping unit 22 and convey it to the heat preservation chamber 4, and then move the molded body M2 into the chamber 41 described later. Alternatively, the processing steps described later can be performed in the mold clamping unit 22 mounted on the injection unit 21.

[0041] (3) Insulated storage and processing procedures like Figure 1As shown, the heat preservation chamber 4 is the part that performs the processing step (second step) of maintaining the molded body M2 formed by the molding section 2 at a temperature T (°C) for a time t (seconds). In other words, the heat preservation chamber 4 controls the temperature of the molded body M2 formed by the molding section 2 to maintain the molded body M2 at a temperature T (°C) for a time t (seconds). As a result, the molded product M3 (second-stage molded body) can be obtained.

[0042] Alternatively, the temperature can be kept constant during the processing steps, or it can be changed during the processing steps as described later.

[0043] The heat preservation chamber 4 includes a chamber 41 and a heater 42. The chamber 41 has a door 411, which is opened for the loading and unloading of the molded body M2. The heater 42 is installed inside the chamber 41 and functions to heat the interior of the chamber 41. Thus, the heater 42 can heat the molded body M2 within the chamber 41. The heater 42 has a thermometer for measuring the temperature inside the heat preservation chamber 4 and is electrically connected to a control unit (not shown) for controlling its operation.

[0044] When the phase transition point Tg of the molded body M2 is set to A (°C), the temperature T (°C) (first temperature T1 (°C)) during the treatment performed in the heat-insulating chamber 4 is set to be above A-10°C and below A+50°C. This improves the heat resistance and strength (impact resistance) of the molded product M3. In other words, through the treatment performed in the heat-insulating chamber 4, a molded product M3 of a cellulose derivative that is environmentally friendly and possesses high heat resistance and strength can be obtained.

[0045] More specifically, in the case of the molded body M2 with a phase transition point Tg of 110°C, the temperature T (°C) (the first temperature T1 (°C)) is preferably 100°C or higher and 160°C or lower. Thus, a molded product M3 of a cellulose derivative with excellent heat resistance and strength can be obtained.

[0046] The processing time of the molded body M2, i.e., the time t (seconds) maintained at the first temperature T1 (°C), is preferably longer than the peak value of the heat absorption of the molded body M2 during the processing step. Exceeding the peak value of the heat absorption of the molded body M2 indicates that the modification of the molded body M2 is promoted. Therefore, the heat resistance and strength of the molded article M3 can be improved more effectively in this processing.

[0047] In the processing step, time t (seconds) (first time t1 (seconds)) can be either the length of the molded body M2 with heat absorption of less than 0.0001 W / g or less than 0.00005 W / g. This processing can more effectively improve the heat resistance and strength of the molded product M3.

[0048] Figure 2A graph showing the time-dependent change in heat absorption of molded body M2, with a phase transition point Tg of 110℃. Figure 2 In the graph shown, the horizontal axis represents time, and the vertical axis represents heat absorption (W / g).

[0049] When the temperature T (°C) (first temperature T1 (°C)) is 100°C, the peak heat absorption is reached at a time t (seconds) of about 400 seconds, and the heat absorption is approximately 0 at a time t (seconds) (time t1 (seconds)) of about 600 seconds.

[0050] When the temperature T (°C) (first temperature T1 (°C)) is 110°C, the heat absorption peak is reached at a time t (seconds) of about 400 seconds, and the heat absorption is approximately 0 at a time t (seconds) (time t1 (seconds)) of about 600 seconds.

[0051] When the temperature T (°C) (first temperature T1 (°C)) is 120°C, the heat absorption peak is reached at a time t (seconds) of about 200 seconds, and the heat absorption is approximately 0 at a time t (seconds) (time t1 (seconds)) of about 500 seconds.

[0052] When the temperature T (°C) (first temperature T1 (°C)) is 130°C, the heat absorption peak is reached at a time t (seconds) of about 1000 seconds, and the heat absorption is approximately 0 at a time t (seconds) (time t1 (seconds)) of about 2800 seconds.

[0053] When the temperature T (°C) (first temperature T1 (°C)) is 140°C, the peak heat absorption is reached at a time t (seconds) of about 1200 seconds, and the heat absorption is approximately 0 at a time t (seconds) (time t1 (seconds)) of about 1900 seconds.

[0054] When the temperature T (°C) (first temperature T1 (°C)) is 150°C, the heat absorption peak is reached at a time t (seconds) of about 700 seconds, and the heat absorption is approximately 0 at a time t (seconds) (time t1 (seconds)) of about 1500 seconds.

[0055] When the temperature T (°C) (first temperature T1 (°C)) is 160°C, the heat absorption peak is reached at a time t (seconds) of about 1000 seconds, and the heat absorption is approximately 0 at a time t (seconds) (time t1 (seconds)) of about 2100 seconds.

[0056] When the temperature T (°C) (first temperature T1 (°C)) is 170°C, the heat absorption peak is reached at a time t (seconds) of about 200 seconds, and the heat absorption is approximately 0 at a time t (seconds) (time t1 (seconds)) of about 1000 seconds.

[0057] When the temperature T (°C) (first temperature T1 (°C)) is 180°C, the heat absorption peak is reached at a time t (seconds) of about 300 seconds, and the heat absorption is approximately 0 at a time t (seconds) (time t1 (seconds)) of about 400 seconds.

[0058] The change in heat absorption over time, as described above, can be determined using differential scanning calorimetry (DSC).

[0059] Therefore, the time t (seconds) can be set according to the temperature T (°C). For example, it can be set to 150 seconds or more and 3500 seconds or less, or it can be set to 270 seconds or more and 1200 seconds or less. This allows for more effective processing of the molded body M2 by the heat preservation chamber 4, thereby more effectively improving the heat resistance and strength of the molded product M3.

[0060] Furthermore, the interior of the insulated chamber 4 is not limited to maintaining a constant temperature T (°C) for a period of time t (seconds). The internal temperature of the insulated chamber 4 can vary within a range of A-10°C to A+50°C, or it can vary intermittently by moving from the range of A-10°C to A+50°C and then into the range of A-10°C to A+50°C. In the case of intermittent temperature variations in the insulated chamber 4, the cumulative time spent in the range of A-10°C to A+50°C is defined as time t (seconds).

[0061] (4) Molded product M3 The article M3 mentioned in this application is obtained by treating the molded body M2 to improve its heat resistance and strength. In addition, the final product after processing and assembling the molded body M2 is also the molded article M3 mentioned in this application.

[0062] (5) Control Department Although not shown in the diagram, the control unit includes a processor, memory, and communication unit. Examples of processors include a CPU and an accelerator processor. The control unit executes the operations of these components to produce the molded product. The following refers to... Figure 3The following explanation is provided. The control unit controls the operation of the insulation chamber 4 to maintain it at a temperature T (°C) (first temperature T1 (°C)). Specifically, the control unit obtains the temperature inside the insulation chamber 4 from the heater 42. If the temperature inside the insulation chamber 4 is lower than the temperature T (°C), the heater 42 is activated to heat the chamber; if the temperature inside the insulation chamber 4 exceeds the temperature T (°C), the heater 42 stops heating. Based on this, the control unit controls the operation of the molding unit 2 to injection mold the material M1 (step S1). Next, the control unit controls the operation of the molding unit 2 and the conveying unit 3 to transfer the generated molded body M2 from the molding unit 2 to the conveying unit 3 (step S2). Then, the control unit opens the door 411 of the insulation chamber 4 (step S3). Next, the control unit controls the operation of the conveying unit 3 to allow the molded body M2 to enter the interior of the insulation chamber 4 through the open door 411 (step S4). Then, the control unit closes the door 411 of the insulation chamber 4 (step S5). The control unit waits for time t (seconds) from the time the molded body M2 enters the heat preservation chamber 4 until time t (seconds) has elapsed. When time t (seconds) has elapsed (step S6: Yes), it proceeds to step S7. Then, the control unit opens the door 411 of the heat preservation chamber 4 (step S7). The control unit controls the operation of the conveyor unit 3 to remove the molded product M3 from the opened door 411 of the heat preservation chamber 4 (step S8). Then, the control unit closes the door 411 of the heat preservation chamber 4 (step S9). Next, the control unit controls the operation of the conveyor unit 3 to transport the removed molded product M3 to the finished product placement area and place it there (step S10). Alternatively, in step S10, the control unit can also place the post-processed molded product M3 or the assembled molded product M3 in the finished product placement area, based on the control of post-processing or assembly of the molded body M2 as needed.

[0063] (6) Summary of this implementation method As explained above, the method for producing a molded article includes a first step of molding a material M1, including a cellulose derivative, into a molded body M2, and a second step of producing a molded article M3 by holding the molded body M2 generated in the first step at a first temperature T1 (°C) for a time t (seconds). When the phase transition point Tg of the molded body M2 is set to A (°C), the first temperature T1 (°C) in the second step is A-10°C or higher and A+50°C or lower. Therefore, a molded article M3 exhibiting excellent heat resistance and strength can be obtained. That is, through the treatment performed in the heat-insulating chamber 4, an environmentally friendly molded article M3 with high heat resistance and strength can be obtained.

[0064] Furthermore, while this embodiment describes the second step being performed in the heat-insulating chamber 4, the invention is not limited to this, and the second step can be performed anywhere. For example, the heat-insulating chamber 4 can be omitted, and the second step can be performed while maintaining the injection molding state. That is, the second step can also be performed in the mold closing unit 22.

[0065] In the second step of the process, the time t is preferably longer than the peak value of the heat absorption of the molded body M2. This allows for a more effective improvement in the heat resistance and strength of the molded body M2.

[0066] The preferred time t in the second step is the length during which the heat absorption of the molded body M2 becomes zero. This allows for a more effective improvement in the heat resistance and strength of the molded body M2.

[0067] The preferred time t is 150 seconds or more and 3500 seconds or less. This can more effectively improve the heat resistance and strength of the molded body M2.

[0068] The cellulose derivative is preferably a cellulose ester. This allows for a more effective improvement in the heat resistance and strength of the molded body M2.

[0069] The cellulose derivative is preferably an incompletely substituted cellulose ester. This allows for a more effective improvement in the heat resistance and strength of the molded body M2.

[0070] The system comprises a molding machine (molding section 2) for molding a material M1 containing a cellulose derivative into a molded body M2, a heat-insulating chamber 4 for holding the molded body M2 formed by the molding section 2 at a first temperature T1 (°C) for a time t (seconds), and a conveyor (conveyor section 3) for conveying the molded body M2 from the molding section 2 to the heat-insulating chamber 4. When the phase transition point Tg of the molded body M2 is set to A (°C), the first temperature T1 (°C) is A-10°C or higher and A+50°C or lower. Therefore, the molded body M2 can exhibit excellent properties. That is, through the treatment performed in the heat-insulating chamber 4, the heat resistance and strength of the molded product M3 can be significantly improved while being environmentally friendly.

[0071] Although preferred embodiments of the present invention have been described above, the present invention is not limited thereto.

[0072] For example, the molded body M2 taken out of the heat preservation chamber 4 can also be cooled.

[0073] Example Next, specific embodiments of the present invention will be described.

[0074] (7) Preparation of raw materials The following materials were prepared for the manufacture of material M1.

[0075] Cellulose (Nippon Paper Manufacturing Co., Ltd. (KC FLOCK, W-50GK)) Acetic acid: (Manufactured by Fujifilm and Koichi Pharmaceuticals (acetic acid)) Propionic anhydride: (Fujifilm and Koichi Pharmaceutical manufacture propionic anhydride) Stearic acid: (Manufactured by Fujifilm and Kohden Pharmaceuticals (stearic acid)) Perchloric acid (manufactured by Fujifilm and Koichi Pharmaceuticals (perchloric acid)) 1,4-Dioxane (manufactured by Fujifilm and Kojun Pharmaceutical Co., Ltd. (1,4-Dioxane)) Methanol (manufactured by Fujifilm and Koichi Pharmaceuticals (methanol)) Isopropyl alcohol (manufactured by Fujifilm and Koichi Pharmaceuticals (isopropyl alcohol)) (8) Manufacturing of molded bodies using raw materials Example 1 First, 5.0 g of stearic acid and 5.0 mL of propionic anhydride were added to a three-necked flask and reacted at 100 °C for 1 hour under a nitrogen atmosphere to synthesize the anhydrides of stearic acid and propionic acid. Then, 100 mL of 1,4-dioxane was added, and the temperature of the reaction solution was lowered to 50 °C. Next, a mixed solution of cellulose activated with acetic acid, 120 μL of perchloric acid, and 50 mL of 1,4-dioxane was added, and the mixture was stirred at 50 °C. After 2 hours, the reaction solution was transferred from the three-necked flask to a beaker, and 1.5 L of a methanol / water mixture (methanol:water = 1:1 vol) was added dropwise as a poor solvent to stop the reaction. The solid precipitated by the dropwise addition was filtered by suction, washed with isopropanol, and further washed with water. Then, the mixture was dried under reduced pressure at 100 °C to obtain the cellulose derivative (material M1).

[0076] The material M1 obtained as described above is then input. Figure 1 The hopper 211 shown enables the manufacturing system 1 to operate, thereby manufacturing the molded product M3.

[0077] The temperature of the material M1 supplied from the injection unit 21 to the mold closing unit 22 is set to 250°C.

[0078] The temperature of the molded body M2 when it is removed from the mold unit 22 is 200°C.

[0079] In addition, the phase transition point Tg of the molded body M2 is 110℃.

[0080] The temperature of the molded body M2 when it is moved into the heat preservation chamber 4 is 90°C. In addition, the temperature T (°C) of the processing carried out in the heat preservation chamber 4 is set to 100°C, and the time t (seconds) to be maintained at temperature T (°C) is set to 600 seconds (10 minutes).

[0081] The average enthalpy change of the molded body M2 in the heat-insulating warehouse 4 is 0.14 J / g per unit time.

[0082] After this process, the molded product M3 of Example 1 was obtained.

[0083] Example 2 Except for setting the temperature T (°C) of the process carried out in the heat preservation chamber 4 to 110°C, the process is the same as in Example 1, thereby obtaining the molded product M3 of Example 2.

[0084] The average enthalpy change of the molded body M2 in the heat-insulating warehouse 4 is 0.13 J / g per unit time.

[0085] Example 3 Except for setting the temperature T (°C) of the treatment in the heat preservation chamber 4 to 120°C and the time t (seconds) of maintaining the temperature T (°C) to 480 seconds (8 minutes), the process is the same as in Example 1, thereby obtaining the molded product M3 of Example 3.

[0086] The average enthalpy change of the formed body M2 in the heat-insulating chamber 4 per unit time is 0.08 J / g.

[0087] Example 4 Except for setting the temperature T (°C) of the treatment in the heat preservation chamber 4 to 130°C and setting the time t (seconds) of maintaining the temperature T (°C) to 2880 seconds (48 minutes), the process is the same as in Example 1, thereby obtaining the molded product M3 of Example 4.

[0088] The average enthalpy change of the molded body M2 in the heat-insulating chamber 4 is 0.98 J / g per unit time.

[0089] Example 5 Except for setting the temperature T (°C) of the treatment in the heat preservation chamber 4 to 140°C and the time t (seconds) of maintaining the temperature T (°C) to 1980 seconds (33 minutes), the process is the same as in Example 1, thereby obtaining the molded product M3 of Example 5.

[0090] The average enthalpy change of the formed body M2 in the heat-insulating chamber 4 per unit time is 1.01 J / g.

[0091] Example 6 Except for setting the temperature T (°C) of the treatment performed in the heat preservation chamber 4 to 150°C and setting the time t (seconds) maintained at temperature T (°C) to 1560 seconds (26 minutes), the process is the same as in Example 1, thereby obtaining the molded product M3 of Example 6.

[0092] The average enthalpy change of the molded body M2 in the heat-insulating chamber 4 is 0.57 J / g per unit time.

[0093] Example 7 Except for setting the temperature T (°C) of the treatment in the heat preservation chamber 4 to 160°C and setting the time t (seconds) of maintaining the temperature T (°C) to 2100 seconds (35 minutes), the process is the same as in Example 1, thereby obtaining the molded product M3 of Example 7.

[0094] The average enthalpy change of the molded body M2 in the heat-insulating chamber 4 is 0.74 J / g per unit time.

[0095] Example 8 Except for setting the temperature T (°C) of the treatment in the heat preservation chamber 4 to 140°C and setting the time t (seconds) of maintaining the temperature T (°C) to 1200 seconds (20 minutes), the process is the same as in Example 1, thereby obtaining the molded product M3 of Example 8.

[0096] The average enthalpy change of the formed body M2 in the heat-insulating chamber 4 is 0.60 J / g per unit time.

[0097] Example 9 Except for setting the first temperature T1 (°C) in the heat preservation chamber 4 to 140°C, setting the time t1 (seconds) maintained at the first temperature T1 (°C) to 2400 seconds (40 minutes), setting the second temperature T2 (°C) to 120°C, and setting the time t2 (seconds) maintained at the second temperature T2 (°C) to 900 seconds (15 minutes), the process is the same as in Example 1, thereby obtaining the molded product M3 of Example 9.

[0098] The average enthalpy change of the formed body M2 in the heat-insulating chamber 4 per unit time is 1.00 J / g.

[0099] Example 10 Except for setting the first temperature T1 (°C) in the heat preservation chamber 4 to 140°C, setting the time t1 (seconds) maintained at the first temperature T1 (°C) to 900 seconds (15 minutes), setting the second temperature T2 (°C) to 120°C, and setting the time t2 (seconds) maintained at the second temperature T2 (°C) to 1800 seconds (30 minutes), everything else is the same as in Example 1, thereby obtaining the molded product M3 of Example 10.

[0100] The average enthalpy change of the formed body M2 in the heat-insulating chamber 4 is 0.60 J / g per unit time.

[0101] Example 11 Except for setting the first temperature T1 (°C) in the heat preservation chamber 4 to 140°C, setting the time t1 (seconds) maintained at the first temperature T1 (°C) to 900 seconds (15 minutes), setting the second temperature T2 (°C) to 150°C, and setting the time t2 (seconds) maintained at the second temperature T2 (°C) to 1200 seconds (20 minutes), everything else is the same as in Example 1, thereby obtaining the molded product M3 of Example 11.

[0102] The average enthalpy change of the formed body M2 in the heat-insulating chamber 4 is 0.90 J / g per unit time.

[0103] Comparative Example 1 Except for setting the temperature T (°C) of the treatment performed in the heat preservation chamber 4 to 170°C and setting the time t (seconds) maintained at temperature T (°C) to 1140 seconds (19 minutes), the process was the same as in Example 1, thereby obtaining the molded product M3 of Comparative Example 1.

[0104] The average enthalpy change of the formed body M2 in the heat-insulating chamber 4 is 0.13 J / g per unit time.

[0105] Comparative Example 2 Except for setting the temperature T (°C) of the treatment performed in the heat preservation chamber 4 to 180°C and setting the time t (seconds) of maintaining the temperature T (°C) to 480 seconds (8 minutes), the process was the same as in Example 1, thereby obtaining the molded product M3 of Comparative Example 2.

[0106] The average enthalpy change of the formed body M2 in the heat-insulating chamber 4 per unit time is 0.14 J / g.

[0107] Comparative Example 3 Except for setting the first temperature T1 (°C) in the heat preservation chamber 4 to 140°C, setting the time t1 (seconds) maintained at the first temperature T1 (°C) to 2400 seconds (40 minutes), setting the second temperature T2 (°C) to 170°C, and setting the time t2 (seconds) maintained at the second temperature T2 (°C) to 1200 seconds (20 minutes), everything else is the same as in Example 1, thereby obtaining the molded article M3 of Comparative Example 3.

[0108] The average enthalpy change of the formed body M2 in the heat-insulating chamber 4 is 0.13 J / g per unit time.

[0109] (9) Evaluation The molded articles manufactured by the methods of producing the molded articles according to the above embodiments and comparative examples are evaluated as follows.

[0110] (9-1) Evaluation of heat resistance The determination was performed in accordance with JISK 7191-2 and evaluated according to the following criteria.

[0111] ◎: Temperatures above 100℃ and below 150℃ 〇: Above 80℃ and below 100℃ ×: Temperature above 50℃ and below 80℃ (9-2) Strength (Impact Resistance) Evaluation The determination was performed in accordance with JISK 711-1 and evaluated according to the following criteria.

[0112] ◎: 10kJ / m 2 Above and 20kJ / m 2 0: 8kJ / m 2 Above and below 10 kJ / m 2 ×:2kJ / m 2 Above and less than 8kJ / m 2 (10) Comprehensive evaluation like Figure 4 As shown in Table 1, in Examples 1 to 11, when the phase transition point of the molded body is set to A (°C), the first temperature T1 (°C) in the second step satisfies the requirement that it is above A-10°C and below A+50°C. Therefore, the molded body obtained can exhibit excellent heat resistance and durability.

[0113] On the other hand, in Comparative Examples 1 and 2, when the phase transition point of the molded body is set to A (°C), the first temperature T1 (°C) in the second step does not meet the requirement of being above A-10°C and below A+50°C. Therefore, the molded body obtained cannot exhibit excellent heat resistance and durability.

[0114] Furthermore, the same applies even if the material of the molded body M2 is replaced with other types of cellulose derivatives.

[0115] Symbol Explanation 1… Manufacturing system; 2… Molding section; 3… Conveying section; 4… Insulation chamber; 21… Injection unit; 22… Mold closing unit; 41… Chamber; 42… Heater; 211… Hopper; 212… Cylinder; 213… Outer cylinder; 214… Screw; 215… Motor; 216… Heater; 217… Opening; 221… Fixed mold; 222… Movable mold; 223… Cavity; 411… Door; M1… Material; M2… Molded body; M3… Molded product.

Claims

1. A method for producing molded articles, characterized in that, Materials including cellulose derivatives are shaped into molded bodies. The generated molded body is subjected to temperature control, maintaining a predetermined temperature range for a predetermined time t. When the phase transition point of the molded body is set to A℃, the temperature range is above A-10℃ and below A+50℃.

2. The method for producing a molded article as described in claim 1, wherein, The time t is the length exceeding the peak value of the heat absorption of the molded body.

3. The method for producing a molded article as described in claim 1, wherein, The time t is the length during which the heat absorption of the shaped body becomes less than 0.0001 W / g.

4. The method for producing a molded article as described in claim 1, wherein, The time t is greater than 150 seconds and less than 3500 seconds.

5. The method for producing a molded article as described in claim 1, wherein, The temperature control controls the heater that heats the molded body in a manner that maintains the molded body within the specified temperature range.

6. The method for producing a molded article as claimed in claim 1, wherein, After the temperature control is completed, the cooling of the molded body begins.

7. A manufacturing system, characterized in that, have: A forming machine that shapes materials, including cellulose derivatives, into shaped bodies; A temperature-controlled chamber that maintains the temperature of the molded body formed by the forming machine within a predetermined temperature range for a predetermined time t. When the phase transition point of the molded body is set to A℃, the temperature range is above A-10℃ and below A+50℃.

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