US-12617130-B2 - Manufacturing of molded article using a composition for molding containing a pyrolytic water discharge substance and a fibroin

US12617130B2US 12617130 B2US12617130 B2US 12617130B2US-12617130-B2

Abstract

The present disclosure relates to a method for manufacturing a molded article in which the molding ability of a protein is improved. Also provided is a composition for molding consisting of at least a mixture of a protein and a pyrolytic water discharge substance is compressed to produce a molded article.

Inventors

Yu Kameno
Jun Miura
Akira Yane

Assignees

CANON VIRGINIA, INC.

Dates

Publication Date: 20260505
Application Date: 20231122

Claims (11)

1 . A method for manufacturing a molded article comprising: heating a composition for molding containing a pyrolytic water discharge substance which decomposes due to pyrolysis to generate water molecules, and a fibroin, and applying pressure to mold the composition while pyrolyzing the pyrolytic water discharge substance, wherein an increase in the amount of weight (Pw) of water released during pyrolysis relative to a weight of the pyrolytic water discharge substance provides an increase in fluidity of the fibroin during molding.
2 . The method for manufacturing a molded article according to claim 1 , wherein the crystallization rate of the fibroin in the molded article is 50% or more.
3 . The method for manufacturing a molded article according to claim 1 , wherein the molding temperature in the process for the molding is not less than T1 and not more than T1+100° C. where the starting temperature of the pyrolysis of the pyrolytic water discharge substance is T1.
4 . The method for manufacturing a molded article according to claim 1 , wherein the molding pressure in the process for the molding is 10 MPa or more and 300 MPa or less.
5 . The method for manufacturing a molded article according to claim 1 , wherein the composition is obtained by a method comprising: obtaining an aqueous solution in which the pyrolytic water discharge substance and a fibroin are dissolved, and obtaining the composition by removing water as a solvent from the aqueous solution.
6 . The method for manufacturing a molded article according to claim 5 , wherein the concentration of the fibroin in the aqueous solution is 2 parts by weight or more and 30 parts by weight or less relative to water as the solvent.
7 . The method for manufacturing a molded article according to claim 5 , wherein the water as the solvent is removed from the aqueous solution by using a freeze-drying method or a spray-drying method.
8 . The method for manufacturing a molded article according to claim 1 , wherein the pyrolytic water discharge substance contains at least one of sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, or ammonium carbonate.
9 . The method for manufacturing a molded article according to claim 1 , wherein the amount of water generated from the pyrolytic water discharge substance during pyrolysis is 1 part by weight or more to 50 parts by weight or less relative to the fibroin.
10 . The method for manufacturing a molded article according to claim 1 , wherein the fibroin is made from silkworm silk and/or its derivatives.
11 . The method for manufacturing a molded article according to claim 1 , wherein the molecular weight of the fibroin is 30 kDa or more and 300 kDa or less.

Description

FIELD OF THE DISCLOSURE The present disclosure relates to a method for manufacturing a molded article containing fibroin. BACKGROUND Efforts have been made to process various products using hydrophilic fibroin. Since fibroin is highly hydrophilic and the binding strength between molecules caused by hydrogen bonds is strong, when applying heat or pressure in the molding process, binding between molecules occurs, and the fluidity of the protein may decrease, and therefore usually relatively high pressure is required. WO 2019054503 A1 provides a method for molding in which a protein is molded at a relatively low pressure by adding a solvent such as water to improve the fluidity. However, it was difficult to mix homogeneously with protein with a small amount of solvent, which could result in insufficient shape transferability at low pressure in areas that did not sufficiently mix with the solvent. In addition, due to the rate of molding and hardening of the protein becoming uneven within the plane, the propagation of pressure could become uneven, which could lead to shape transferability becoming insufficient. On the other hand, when increasing the amount of solvent, the fluidity of protein could improve at low pressure. However, due to the sudden vaporization-heat of water caused by the heat of the molding of the protein was deprived of heat, and there were cases where without the protein flowing a molded part of the desired shape could not be obtained. The present disclosure aims to improve molding fluidity when obtaining a molded part containing protein. SUMMARY OF THE DISCLOSURE The present disclosure relates to a method for manufacturing comprising a process for heating a composition for molding containing a pyrolytic water discharge substance, which decomposes due to pyrolysis to generate water molecules, and a fibroin, and a process for applying pressure and molding while subjecting the pyrolytic water discharge substance to pyrolysis. 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 The accompanying drawings, which are incorporated herein and form part of the specification, illustrate various embodiments, objects, features, and advantages of the present disclosure. FIG. 1 is a schematic cross sectional view of the mold for molding used in the present disclosure. FIG. 2A-D is a table providing results from the present Examples. FIG. 3 is a process flowchart depicting a method for obtaining a powder according to the present disclosure. FIG. 4 is a process flowchart depicting a method for molding according to the present disclosure. 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 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. Composition for Molding The composition for molding of the present disclosure contains a pyrolytic water discharge substance. In the specification of this application, pyrolytic water discharge substance means a compound that is a solid below normal temperature, but whose structure decomposes by heat (pyrolysis), and contains water molecules in the decomposed substance. Here, a normal temperature is, for example, 27° C. By mixing a pyrolytic water discharge substance with a molding element (for example, a protein-containing powder) and compression molding it, the pyrolytic water discharge substance decomposes due to the heat generated during molding. The fluidity of the protein improves by the protein absorbing the water generated at this time. That is, the viscosity of a composition can be decreased. An exemplary process for obtaining a composition for molding is described in FIG. 3. In step S11, an aqueous solution is prepared as otherwise described in the present disclosure above. In Step S12, a pyrolytic water discharge substance is added to the aqueous solution as described herein above. In Step S13, water is removed from the aqueous solution com