Method for producing organic polymers, and molded bodies, and molds for molding of the organic polymers

Abstract

The present disclosure relates to a method for producing a molded body with sufficient strength by heating and pressurizing in a mold, and to provide a molded body. Therefore, a method for molding an organic polymer, including externally heating the organic polymer, applying ultrasonic waves to the organic polymer, and pressurizing the organic polymer, wherein the start of the application to the organic polymer is performed after the start of the heating is provided.

Description

METHOD FOR PRODUCING ORGANIC POLYMERS, AND MOLDED BODIES, ANDMOLDS FOR MOLDING OF THE ORGANIC POLYMERS

[0001] FIELD OF THE DISCLOSURE

[0002] The present disclosure relates to a method for producing organic polymer molded bodies.

[0003] BACKGROUND

[0004] As described in Japanese Patent Publication No. 2021 / 80304 and Japanese Patent No. 06904535, molded bodies of materials containing polypeptides, which are a kind of organic polymers, are known. These molded bodies are obtained by heating and pressurizing the material into sheets or powders in a mold.

[0005] In the method of laminating sheets, sufficient flexural strength was exerted in the direction in which the thin films were laminated, but on the other hand, flexural strength sometimes became insufficient for forces in the direction parallel to the thin films. In the method using powder, it was conjectured that the strength of the molded body increased as the particle size of the powder became smaller, but sometimes it was difficult to obtain a powder with a sufficiently small particle size, and sufficient strength was not obtained.

[0006] Therefore, there is a need for a method for molding an organic polymer, by which a molded body of sufficient strength can be obtained.SUMMARY OF THE DISCLOSURE

[0007] The present disclosure relates to a method for molding an organic polymer, by which a molded body of sufficient strength can be obtained.

[0008] Thus, in one aspect, the present disclosure provides a method for molding an organic polymer, comprising a step of externally heating the organic polymer, a step of applying ultrasonic waves to the organic polymer, and a step of pressurizing the organic polymer, and wherein the start of the application of the ultrasonic waves is performed after the start of the external heating.

[0009] In another aspect, there is provided an organic polymers molding apparatus, comprising a mold, a heating means for externally heating the organic polymer, an ultrasonic applying means for applying ultrasonic waves to the organic polymer, and a pressurizing means for applying pressure to the organic polymer, and wherein the ultrasonic applying means is configured to apply ultrasonic waves in a direction parallel to the pressurizingdirection and in a direction perpendicular to the pressurizing direction by the pressurizing means.

[0010] In a further aspect, in preparing a molded body manufactured by heating and pressurizing it inside a mold, methods for producing a molded product with sufficient strength and a molded body are provided.

[0011] These and other embodiments, objects, features, and advantages of the present disclosure will become apparent upon reading the following detailed description of exemplary embodiments of the present disclosure, when taken in conjunction with the appended drawings, and provided claims.BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The accompanying drawings, which are incorporated herein and form part of the specification, illustrate various embodiments, objects, features, and advantages of the present disclosure.

[0013] FIG. 1 is a schematic diagram of a mold for molding organic polymers.

[0014] FIG. 2 is a schematic diagram of the mold for molding organic polymers used in the embodiment.

[0015] FIG. 3 is a schematic diagram of the organic polymer molded body molded in the embodiment and the measuring portion of its strength.

[0016] FIG. 4 is a graph showing piston drop amount vs. temperature, with the melting temperature identified at the intersection of the dotted lines (which location is circled).

[0017] Throughout the figures, the same reference numerals and characters, unless otherwise stated, are used to denote like features, elements, components or portions of the illustrated embodiments. Moreover, while the subject disclosure will now be described in detail with reference to the figures, it is done so in connection with the illustrative exemplary embodiments. It is intended that changes and modifications can be made to the described exemplary embodiments without departing from the true scope and spirit of the subject disclosure as defined by the appended claims.DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENT

[0018] The present disclosure has several embodiments and relies on patents, patent applications and other references for details known to those of the art. Therefore, when a patent, patent application, or other reference is cited or repeated herein, it should be understood that it is incorporated by reference in its entirety for all purposes as well as for the proposition that is recited.

[0019] One of the features of the manufacturing method of the present disclosure is filling a molding material composed of an organic polymer into a mold, and applying ultrasonic waves to it. Thus, high strength molding bodies are obtained. This effect is more pronounced for polymers with amide bonds and becomes even more pronounced for polypeptides with a higher proportion of amide bonds in the molecule.

[0020] This is thought to occur because by increasing the amide bonds in the molecule, the chain becomes rigid and plasticity is reduced, so while sufficient chain entanglements and interactions do not form by just heating or pressurization, applying ultrasonic waves to these molecules does increase chain entanglements and interactions resulting in the formation of higher order structures.

[0021] Furthermore, heat, ultrasonic vibration and pressure can be simultaneously applied to the organic polymer by filling the mold with a molding material composed of the organic polymer and then pressurizing it while applying external heating and ultrasonic application. In this case, compared with the case where only ultrasonic vibration and pressure are applied, a molded body with even higher strength can be obtained. This effect is assumed to be due to the increased fluidity of the molecular chains and the increased entanglement and interaction of the molecular chains by applying pressure while applying ultrasonic waves to the loosened constraints between the molecular chains due to heat, resulting in the enhanced strength of the molded body.

[0022] In addition, a higher intensity can be obtained by starting the application of ultrasonic waves after starting the external heating.

[0023] The following are individual descriptions of the organic polymers, molding material, molding, and measurement method used in the present disclosure.

[0024] ORGANIC POLYMERS

[0025] Organic polymers can develop strong strength through entanglement and interaction within polymer chains and / or between polymer chains.

[0026] Although there are no particular restrictions on the organic polymers used in the present disclosure, in one embodiment, the organic polymers are polymers having amidebonds, because polymers having amide bonds form interactions between the amide bonds and enhance their strength. Examples of polymers having amide bonds include nylon 6 and nylon 12.

[0027] It is also desirable that organic polymers are polypeptides that have many amide bonds in their molecules. In some embodiments, the organic polymers should be fibroins or a derivative of these.

[0028] Examples of polypeptides include poly-L-lysine and polyalanine. And, fibroin is a protein that can he extracted from cocoons and nests, and silk fibroin, hornet silk and spider silk can be exemplified. The extraction of fibroin can be carried out, for example, with the method described in WO 2006 / 101223. Silk fibroin forms a secondary structure called beta sheet in the polymer chain, which gathers and crystallizes to express extremely high strength. In addition, hornet silk is a protein produced by wasp larvae, expresses an even stronger strength by forming a secondary structure called coiled-coil structure, formed by alpha helix gathering.

[0029] Additives may also be added to these organic polymers to the extent that they do not impair their properties.

[0030] MOLDING MATERIAL

[0031] Organic polymers can be used as molding materials. There are no particular restrictions on the form of the molding material, but examples include pellets, sheets, films, powders and flakes. Organic polymers can be synthesized or extracted to obtain flaky materials. A powdery material can be obtained by grinding this flaky material. A jet mill, hammer mill, ball mill, pin mill or the like can be used as a grinding method. In addition, powder material with uniform particle size can be obtained by performing screening after grinding.

[0032] In addition, pellet-like materials can be obtained by cutting a flaky material that is extruded into a strand after heating and melting it, or by pressing a flaky material into a shape such as a cylindrical shape at room temperature or in a heated state.

[0033] Sheet-like (film-like) materials can be obtained by heating and melting flaky or pellet-like materials and extruding them onto sheets, or by dissolving the materials into a solvent to form a solution and then applying it to a base material with a spray or a dispenser to dry and peel it off.

[0034] One form of the molding material may be used, or several forms may be mixed to be used.

[0035] MOLDING

[0036] Organic polymer molded bodies can be obtained by filling a mold with molding materials composed of organic polymers, and applying ultrasonic waves. This is because formation of higher-order structures is promoted by applying ultrasonic waves.

[0037] It is desirable to apply external heating and pressurization in conjunction with the application of ultrasonic waves. Furthermore, it is desirable to start the application of ultrasonic waves after heating. This is because by increasing the fluidity of the molecular chains by applying pressure while applying ultrasonic waves, while the constraints between the organic polymer chains are being loosened by heating, the entanglement and interaction of the molecular chains can be increased, increasing the strength of the molded body.

[0038] FIG. 1 is a schematic diagram of an example of a mold 3 that can be used for the molding of organic polymers. The mold 3 consists of a temperature-adjustable part having a through-hole (a cylinder), upper and lower pistons 1 and 2, and ultrasonic vibrators 4 and 5. The ultrasonic vibrators 4 and 5 vibrate in the direction of the arrow. Organic polymer molded bodies can be obtained by loading a molding material composed of organic polymer into the through-hole of the cylinder 3, and compressing the organic polymer with the pistons 1 and 2 while applying ultrasonic vibrations using the ultrasonic vibrators 4 and 5.

[0039] For external heating, the temperature-adjustable part are inserted into a heater (heating furnace) 6. The external heating can also be achieved by a method of setting a heater such as a cartridge heater in the mold to heat the mold or using electromagnetic induction, etc. to raise the temperature of the mold by letting the mold generate heat, to heat the organic polymer by heat conduction from the mold can be used. In addition, a method of heating the organic polymer by passing heated air through the mold or a method of using a light-transmitting mold instead of the mold, and heating the organic polymer by irradiating light from the outside may be used.

[0040] It is desirable for the temperature of the external heating to be above the glass transition temperature of the molding material, and even more desirable for it to be above the softening temperature. When exceeding the glass transition temperature, the fluidity of the molecular chains increases because the intermolecular bonds of the amorphous are broken. Furthermore, when exceeding the softening temperature, the fluidity increases significantly. On the other hand, it is desirable for the temperature of the external heating to be below the decomposition starting temperature. This is because when the decomposition temperature is exceeded, a breaking of the covalent bonds in the molecular chains occurs, resulting in a lowering of the molecular weight and possibly a lowering of the strength of the molded body.

[0041] The glass transition temperature of the molding material can be measured using differential scanning calorimetry (DSC). And, the softening temperature of the molding material can be measured with a thermal flow evaluation device (flow tester). In addition, the decomposition starting temperature of the molding material can be measured using thermogravimetric analysis (TGA).

[0042] Pressurization is performed by setting the mold in a press machine and pressing down the pistons 1 and 2. It is desirable for the pressure to be applied to be 1 MPa or more, and it is more desirable for it to be 100 MPa or more. This is because the higher the pressure, the closer the distance between the molecular chains becomes, which makes entanglement and interaction between the molecular chains more likely to occur.

[0043] For the application method of the ultrasonic waves, the method of letting the ultrasonic vibrators 4 and 5 contact the mold to transmit the vibrations can be used. As general types, there are electro- strictive and magneto-strictive types of ultrasonic vibrators, but any type can be used as long as ultrasonic waves can be applied. The frequency of the ultrasonic waves can be from 20 kHz or more to 1 MHz or less, and can be from 20 kHz or more to 100 kHz or less.

[0044] The ultrasonic vibrator may be installed in any manner as long as it contacts the mold, but one can be installed on both the piston side (piston 1 and / or 2) and the cylinder side (cylinder 3). In addition, when installing a plurality of ultrasonic vibrators, the directions of the vibration of the ultrasonic vibrators can be in different directions, including for them to be orthogonal. As shown in FIG. 1, for example, it may be configured so the ultrasonic waves are applied in the direction parallel and the direction perpendicular to the direction in which pressure is applied. This is because by vibrating the molecular chains in a plurality of directions, the movements of the molecular chains become complex, and entanglement of the molecular chains occurs efficiently.

[0045] The timing of the start of the application of ultrasonic waves can be after the start of the external heating. This is for the following reasons.

[0046] With external heating, the temperature rises gradually from the outside where it touches the mold, so the molding material integrates from the outside. When the outside is integrated (welded), the escape route for the trace amount of moisture included in the organic polymer is blocked by the welded periphery, so the condition that includes the moisture will be maintained even when heating it. Organic polymers with bonds such as amide bonds have the characteristic of improving fluidity by containing moisture, so when applying ultrasonicvibration in this condition, the formation of entanglements and bonds between the polymer chains progresses rapidly.

[0047] When the temperature of the molding material rises due to heat generated by ultrasonic vibration without conducting external heating, the temperature of all the material for molding rises uniformly. Therefore, the inside of the molding material is heated before the outside of the molding material integrates, causing the moisture to escape from the molding material resulting in low fluidity. Thus, the above-mentioned effect does not occur when ultrasonic vibration alone.

[0048] MEASUREMENT METHOD

[0049] Flexural strength was measured using an Instron universal tester (Type 5582, manufactured by Instron). The distance between fulcrums of the three-point bending was fixed at 27 mm, and the measurement speed was set at 1 mm / min. The flexural strength was defined as the value of the flexural stress during maximum load until the specimen was destroyed.

[0050] For the glass transition temperature, the midpoint glass transition temperature was measured by DSC using a thermal analysis system (DSC 823 manufactured by Mettler Toledo) according to JIS K 7121-1987 with the condition of a temperature rising speed of 10 degrees Celsius per minute.

[0051] The softening temperature can be measured using a constant load extrusion method tubular rheometer "Flow characteristic evaluation device" (a flow tester) (CFT-500D, manufactured by Shimadzu Corporation).

[0052] The CFT-500D is a device that can graph a flow curve from the drop amount (mm) and temperature (degrees Celsius) of the piston when a constant load is applied by the piston from the top, while the measured sample filled in the cylinder is melted and extruded from the tubular hole at the bottom of the cylinder while the temperature is being raised.

[0053] In the present disclosure, the softening temperature (Tm) is defined as the "melting temperature in the 1 / 2 method" listed in the manual attached to the "Flow Tester CFT-500D," a flow characteristic evaluation device.

[0054] The melting temperature in the 1 / 2 method is calculated as follows.

[0055] First, determine 1 / 2 of the difference between the drop amount of the piston (Define the end point of the outflow as Smax) occurring the moment the outflow ends, and the drop amount of the piston (Define the lowest point as Smin) at the moment the outflow starts. (Define this as X. X = (Smax - Smin) / 2). Then, define the temperature of the flowcurve when the drop amount of the piston equals the sum of X and Smin as the melting temperature in the 1 / 2 method.

[0056] In addition, when the viscosity is too high and there is no outflow from the tubular hole, the melting temperature or softening temperature can be defined as the temperature at the intersection point between the straight line extending the baseline on the low temperature side to the high temperature side in a graph showing the drop amount of the piston versus temperature, and the tangential line at the inflection point of the curve, as shown in FIG. 4.

[0057] The decomposition temperature is the temperature at which decomposition begins when the temperature is raised to 25 ~ 400 degrees Celsius at 1 degree Celsius per minute in the atmosphere as determined by thermogravimetric analysis (TG) (TGA851, manufactured by Mettler Toledo). The decomposition start temperature is defined as the temperature at the intersection point of the straight line extending the baseline of the low temperature side to the high temperature side and the tangential line at the inflection point of the TG curve.

[0058] EXAMPLES

[0059] EXAMPLE 1

[0060] After washing silkworm cocoons with water, they were boiled in a 0.02 mol / L sodium carbonate aqueous solution for 30 minutes to conduct degumming. The degummed silk thread was dissolved by pouring it into a 9.3 mol / L LiBr aqueous solution and agitating it at 60 degrees Celsius for 4 hours. Desalination was performed using 30 / 32 cellulose tubes (fractionated molecular weight of 12000 - 14000) manufactured by Sekisui Chemical Co. The concentration of the aqueous solution of silk fibroin after desalination was diluted with pure water so it became 5%.

[0061] The silk fibroin solution was applied onto a glass substrate using a bar coater (#22, manufactured by Mitsui Electric Refinery) and then dried at room temperature for 1 hour, followed by 5 hours at 80 degrees Celsius. After that, the dried film was peeled off from the substrate and a film-like material for molding was obtained. After this was left in an environment with a room temperature of 23 degrees Celsius and 50% humidity for 24 hours, the film thickness was 3.2 microns when measured. When the glass transition temperature, softening temperature and decomposition temperature were measured respectively, they were 64 degrees Celsius, 80 degrees Celsius and 185 degrees Celsius, respectively.

[0062] Subsequently, the element for molding was molded using a mold 13 (with reference to FIG. 2). For the mold 13, a mold with a square columnar through-hole of 80 mm in length and 15 mm in width was used. For the lower piston 12, one with a groove of 2 mm in width and 35 mm in depth carved in the center, as shown in FIG. 2, was used. Ultrasonic vibrators 15 and 14 vibrating in the direction of the arrows were installed in the lower piston 12 and mold 13, respectively. The remaining mold set up included upper piston 11, in which no groove was provided, and the mold was inserted into heater 16.

[0063] Two types of silk fibroin thin films, 15 mm in length and 2 mm in width, and 80 mm in length and 15 mm in width, were prepared. The former was set in the groove part of the lower piston and the latter was set between the upper and lower pistons. At this time, the total amount of film set was 4.5 g. It was set in a press and pressurized at a pressure of 600 MPa. Then, after heating it to 120 degrees Celsius by using the heater (heating furnace) 16, ultrasonic vibrations were applied for 30 seconds using the ultrasonic vibrators installed in mold parts 11 and 12. Immediately after ending the ultrasonic wave application, the mold was taken out and after cooling it to room temperature, the silk fibroin molded body 25 was obtained. Parts 21 and 22 of FIG. 3 were cut out of molded body 25 to measure the strength, and the part of 21 measured was defined as "longitudinal strength" and the part of 22 measured was defined as "transverse strength". The longitudinal strength and transverse strength were 132 MPa and 130 MPa, respectively. Sufficient strength was confirmed in both the longitudinal direction and the transverse direction.

[0064] COMPARATIVE EXAMPLE 1

[0065] A silk fibroin molded body was obtained with the same procedure as in Example 1 except that ultrasonic vibration was not applied. When the longitudinal strength and transverse strength were measured, they were 21 MPa and 124 MPa, respectively. In the transverse direction, sufficient strength was obtained, but there was a marked decrease in the strength in the longitudinal direction.

[0066] EXAMPLE 2

[0067] A silk fibroin molded body was obtained with a similar operation, except that the order of external heating and pressurization was changed so it was pressurized at a pressure of 600 MPa after the mold was heated to 120 degrees Celsius. When the longitudinal strength and transverse strength were measured, they were 131 MPa and 132 MPa, respectively. Sufficient strength was confirmed in both the longitudinal direction and the transverse direction.

[0068] EXAMPLE 3

[0069] A silk fibroin aqueous solution that was obtained with an operation similar to Example 1 was freeze-dried using a freeze-dryer (FD-550P) manufactured by Tokyo Rika Machinery Co., Ltd. For the freeze-drying conditions, after freezing it at -30 degrees Celsius, the atmosphere was decompressed, after which the temperature was raised to -6 degrees Celsius and it was freeze-dried for 100 hours. When measuring the bulk specific gravity, it was 0.03 g / cm3.

[0070] Next, the silk fibroin was cut into portions of approximately 20 mg and fed into a mold with a cylindrical through-hole of 3 mm in diameter, pressurized at 25 degrees Celsius and 30 MPa, and then taken out to obtain the material for molding. When the bulk specific gravity of the obtained material for molding was measured, it was 1.04 g / cm3. 4.5 g of molding material was measured and taken out, fed into the mold, and thereafter, the silk fibroin molding body was obtained with an operation similar to Example 1. When the longitudinal strength and transverse strength were measured, they were 126 MPa and 128 MPa, respectively. Sufficient strength was confirmed in both the longitudinal direction and the transverse direction.

[0071] EXAMPLE 4

[0072] Powdery material for molding was obtained by pulverizing freeze-dried silk fibroin, obtained with an operation similar to Example 3, for 3 seconds 10 times using an OML-1 laboratory mill manufactured by Tokyo Rika Machinery. 4.5 g of the material for molding material was measured and taken out, and fed into the mold, after which, the silk fibroin molded body was obtained with an operation similar to Example 1. When the longitudinal strength and transverse strength were measured, they were 124 MPa and 125 MPa, respectively. Sufficient strength was confirmed in both the longitudinal direction and the transverse direction.

[0073] EXAMPLE 5

[0074] A silk fibroin molded body was obtained with an operation similar to Example 1, except that the external heating temperature was changed to 100 degrees Celsius. When the longitudinal strength and transverse strength were measured, they were 110 MPa and 121 MPa, respectively. Sufficient strength was confirmed in both the longitudinal direction and the transverse direction.

[0075] EXAMPLE 6

[0076] A silk fibroin molded body was obtained with an operation similar to Example 1, except that the external heating temperature was changed to 80 degrees Celsius. When the longitudinal strength and transverse strength were measured, they were 92 MPa and 98 MPa,respectively. Sufficient strength was confirmed in both the longitudinal direction and the transverse direction.

[0077] EXAMPLE 7

[0078] Cocoons collected from wasp's nests were cut into pieces of approximately 5 mm in size, and impurities were removed to the extent that they could be visually confirmed. The cocoon fragments were placed in a 9 mol / L LiBr aqueous solution and agitated at 40 degrees Celsius for 1 hour to let the cocoons dissolve. The agitated LiBr aqueous solution was centrifuged to separate and remove the impurities which are insoluble components.

[0079] Next, the LiBr solution, from which the impurities were removed, was placed in a 30 / 32 (fractionated molecular weight, 12000 - 14000) cellulose tube manufactured by Sekisui Chemical Co., Ltd., and dialysis was conducted in distilled water at room temperature for 4 days to remove the LiBr.

[0080] After the dialysis, the contents of the dialysis tube were freeze-dried using a freeze-dryer (FD-550P) manufactured by Tokyo Rika Machinery Co., Ltd. For the freeze- drying conditions, after freezing it at -30 degrees Celsius, the atmosphere was decompressed, after which the temperature was raised to -6 degrees Celsius and it was freeze-dried for 100 hours, to obtain spider silk.

[0081] The obtained spider silk was pulverized repeatedly using a freeze-grinder (HTPH-01) manufactured by AS ONE Corporation, and only the pieces that could pass through a sieve with a mesh opening of 45 microns were collected to obtain the material for powder molding.

[0082] 4.5 g of the material for molding was measured and taken out, and fed into the mold, after which a spider silk molded body was obtained with an operation similar to Example 1. When the longitudinal strength and transverse strength were measured, they were 156 MPa and 159 MPa, respectively. Sufficient strength was confirmed in both the longitudinal direction and the transverse direction.

[0083] EXAMPLE 8

[0084] Using Unitika Nylon 6 (PA6: A1015LP-20) manufactured by Unitika Corporation as a material for molding, 4.5 g was measured and take out, and fed into a mold, after which a nylon molded body was obtained with an operation similar to Example 1. When the longitudinal strength and transverse strength were measured, they were 112 MPa and 114 MPa, respectively. Sufficient strength was confirmed in both the longitudinal direction and the transverse direction.

[0085] EXAMPLE 9

[0086] A silk fibroin molded body was obtained with an operation similar to Example 1 except that only the ultrasonic vibrator installed in the mold part 12 was used. When the longitudinal strength and transverse strength were measured, they were 118 MPa and 130 MPa, respectively. Sufficient strength was confirmed in both the longitudinal direction and the transverse direction.

[0087] EXAMPLE 10

[0088] A silk fibroin molded body was obtained with an operation similar to Example 1 , except that only the ultrasonic vibrator installed in the mold part 13 was used. When the longitudinal strength and transverse strength were measured, they were 105 MPa and 130 MPa, respectively. Sufficient strength was confirmed in both the longitudinal direction and the transverse direction.

[0089] EXAMPLE 11

[0090] A silk fibroin molded body was obtained with an operation similar to Example 1, except that the order of external heating and pressurization, and then the ultrasonic waves was changed, so the external heating was started after pressurization, and ultrasonic waves were applied from the moment the mold temperature reached 100 degrees Celsius, until it reached 120 degrees Celsius. When the longitudinal strength and transverse strength were measured, they were 105 MPa and 119 MPa, respectively. Sufficient strength was confirmed in both the longitudinal direction and the transverse direction.

[0091] EXAMPLE 12

[0092] A silk fibroin molded body was obtained with an operation similar to Example 1, except that the order of external heating and pressurization, and then the ultrasonic waves was changed, so that after pressurization, the ultrasonic wave application was started at the same time, and 10 seconds after that the external heating was started, and the application of ultrasonic waves was continued until the mold temperature reached 120 degrees Celsius. When the longitudinal strength and transverse strength were measured, they were 101 MPa and 116 MPa, respectively. Sufficient strength was confirmed in both the longitudinal direction and the transverse direction.

[0093] EXAMPLE 13

[0094] A silk fibroin molded body was obtained with an operation similar to Example 1, except that the order of external heating and pressurization, and then the ultrasonic waves was changed, so that after pressurization, the external heating and ultrasonic wave application were started at the same time, and the application of ultrasonic waves was continued until the mold temperature reached 120 degrees Celsius. When the longitudinalstrength and transverse strength were measured, they were 96 MPa and 111 MPa, respectively. Sufficient strength was confirmed in both the longitudinal direction and the transverse direction.

[0095] EXAMPLE 14

[0096] A silk fibroin molded body was obtained with an operation similar to Example 1, except that the external heating temperature was changed to 180 degrees Celsius. When the longitudinal strength and transverse strength were measured, they were 90 MPa and 88 MPa, respectively. Sufficient strength was confirmed in both the longitudinal direction and the transverse direction.

[0097] COMPARATIVE EXAMPLE 2

[0098] A silk fibroin molded body was obtained with an operation similar to Example 1, except that external heating was not conducted, and applying ultrasonic vibration for 30 seconds and leaving it for 30 seconds was repeated 5 times. When the longitudinal strength and transverse strength were measured, they were 68 MPa and 125 MPa, respectively.Sufficient strength was confirmed in both the longitudinal direction and the transverse direction.

[0099] Definitions[000100] In referring to the description, specific details are set forth in order to provide a thorough understanding of the examples disclosed. In other instances, well-known methods, procedures, components and circuits have not been described in detail as not to unnecessarily lengthen the present disclosure.[000101] It should be understood that if an element or part is referred herein as being "on", "against", "connected to", or "coupled to" another element or part, then it can be directly on, against, connected or coupled to the other element or part, or intervening elements or parts may be present. In contrast, if an element is referred to as being "directly on", "directly connected to", or "directly coupled to" another element or part, then there are no intervening elements or parts present. When used, term "and / or", includes any and all combinations of one or more of the associated listed items, if so provided.[000102] Spatially relative terms, such as “under” “beneath”, "below", "lower", "above", "upper", “proximal”, “distal”, and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) or feature(s) as illustrated in the various figures. It should be understood, however, that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, a relative spatial term such as "below" can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein are to be interpreted accordingly. Similarly, the relative spatial terms “proximal” and “distal” may also be interchangeable, where applicable.[000103] The term “about,” as used herein means, for example, within 10%, within 5%, or less. In some embodiments, the term “about” may mean within measurement error.[000104] The terms first, second, third, etc. may be used herein to describe various elements, components, regions, parts and / or sections. It should be understood that these elements, components, regions, parts and / or sections should not be limited by these terms. These terms have been used only to distinguish one element, component, region, part, or section from another region, part, or section. Thus, a first element, component, region, part, or section discussed below could be termed a second element, component, region, part, or section without departing from the teachings herein.[000105] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. The use of the terms “a” and “an” and “the” and similar referents in the context of describing the disclosure (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “includes”, “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Specifically, these terms, when used in the present specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof not explicitly stated. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value isincorporated into the specification as if it were individually recited herein. For example, if the range 10-15 is disclosed, then 11, 12, 13, and 14 are also disclosed. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the disclosure and does not pose a limitation on the scope of the disclosure unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the disclosure.[000106] It will be appreciated that the methods and compositions of the instant disclosure can be incorporated in the form of a variety of embodiments, only a few of which are disclosed herein. Variations of those embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the disclosure to be practiced otherwise than as specifically described herein. Accordingly, this disclosure includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the abovedescribed elements in all possible variations thereof is encompassed by the disclosure unless otherwise indicated herein or otherwise clearly contradicted by context.

Claims

WHAT IS CLAIMED IS:

1. A molding method for an organic polymer, comprising: externally heating the organic polymer, applying ultrasonic waves to the organic polymer, and pressurizing the organic polymer, wherein starting the application of the ultrasonic waves is conducted after starting the external heating.

2. The molding method according to claim 1, wherein the organic polymer is a polymer compound having amide bonds.

3. The molding method according to claim 1, wherein the organic polymer is a polypeptide.

4. The molding method according to claim 1, wherein the organic polymer is a silk fibroin and a derivative thereof.

5. The molding method according to any of claims 1 to 4, wherein the organic polymer is an aggregate of materials separated into a plurality of parts.

6. The molding method according to any of claims 1 to 4, wherein the organic polymer is in a sheet form.

7. The molding method according to any of claims 1 to 4, wherein the organic polymer is pelletized or powdery form.

8. The molding method according to any of claims 1 to 7, wherein the temperature of the organic polymer at starting application of ultrasonic waves is not less than the softening temperature of the organic material.

9. The molding method according to any of claims 4 to 7, wherein the temperature of the organic polymer at starting application of ultrasonic waves is not less than a softening temperature of not less than 80 degrees Celsius.

10. The molding method according to any of claims 1 to 9, wherein in the process of external heating, a mold containing the organic polymer is heated from the outside, and the organic polymer is heated by heat conduction from the mold to the organic polymer.

11. The molding method according to any of claims 1 to 9, wherein in the process of external heating, the organic polymer is heated by irradiating the organic polymer with light from outside the mold containing the organic polymer or by sending warm air from outside the mold containing the organic polymer.

12. The molding method according to claim 1, wherein in the process of applying ultrasonic waves, the ultrasonic waves are applied so that the ultrasonic wave is applied in a direction parallel to the pressurizing and in a direction perpendicular to the pressurizing direction occurring in the pressurizing process.

13. An apparatus for molding organic polymers, comprising a mold, a heating means for externally heating the organic polymer, an ultrasonic wave application means for applying ultrasonic waves to the organic polymer, and a pressurizing means for applying pressure to the organic polymer, wherein the ultrasonic wave application means is configured to apply ultrasonic waves in a direction parallel to the pressurizing direction and in a direction perpendicular to the pressurizing direction by the pressurizing means.

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