KR-20260062937-A - Method for manufacturing a cellulose dispersion derived from regenerated cellulose and a cellulose molded body derived from regenerated cellulose, and a cellulose dispersion derived from regenerated cellulose, cellulose beads derived from regenerated cellulose, and a cellulose molded body derived from regenerated cellulose.

KR20260062937AKR 20260062937 AKR20260062937 AKR 20260062937AKR-20260062937-A

Abstract

[Problem] This invention relates to a cellulose dispersion and a method for manufacturing a cellulose molded body, wherein a suitable recycled cellulose, including cellophane that is difficult to recycle, can be used as a dispersion raw material. [Solution] The method comprises a grinding process (S1) in which regenerated cellulose is used as a dispersion raw material and the dispersion raw material is ground, a depolymerization process (S2) in which the degree of polymerization of the ground raw material obtained by the grinding process is reduced to 350 or less, a micronization process (S3) in which the depolymerized cellulose obtained by the depolymerization process is micronized to obtain a cellulose dispersion, and also a molding process (S4) in which the cellulose dispersion obtained by the micronization process is dried to obtain a molded body.

Inventors

이와타 잇페이
야마자키 아스카

Assignees

후타무라 가가쿠 가부시키가이샤

Dates

Publication Date: 20260507
Application Date: 20240529
Priority Date: 20230905

Claims (15)

Regenerated cellulose is used as a dispersion raw material, and A grinding process for grinding the above-mentioned dispersion raw material, and A depolymerization process for reducing the degree of polymerization of the ground raw material obtained by the above-mentioned grinding process to 350 or less, and A method for preparing a cellulose dispersion derived from regenerated cellulose, characterized by including a micronization process to obtain a cellulose dispersion by micronizing the depolymerized cellulose obtained by the above depolymerization process.
A method for preparing a cellulose dispersion derived from regenerated cellulose, wherein the degree of polymerization of the regenerated cellulose of the dispersion raw material is 600 or less, in accordance with claim 1.
A method for preparing a cellulose dispersion derived from regenerated cellulose, wherein, in the depolymerization process of claim 1 or 2, the degree of polymerization of the ground raw material is reduced by sodium hypochlorite with an effective chlorine concentration of 0.13% or higher.
A method for preparing a cellulose dispersion derived from regenerated cellulose, wherein, in the depolymerization process of claim 1 or 2, the degree of polymerization of the ground raw material is reduced by sodium hypochlorite with an effective chlorine concentration of 3% or more.
A cellulose dispersion obtained by the manufacturing method described in claim 1 or 2, wherein the cation requirement of the cellulose dispersion is 4.0 μeq/g cell or more per 1 g of cellulose.
A cellulose dispersion obtained by the manufacturing method described in paragraph 3, wherein the cation requirement of the cellulose dispersion is 4.0 μeq/g cell or more per 1 g of cellulose.
A cellulose dispersion obtained by the manufacturing method described in paragraph 4, wherein the cation requirement of the cellulose dispersion is 50.0 μeq/g cell or more per 1 g of cellulose.
A method for manufacturing a cellulose-derived molded body comprising a molding process of drying and molding the cellulose dispersion obtained by the manufacturing method described in claim 1 to obtain a cellulose-derived molded body.
A method for manufacturing a cellulose molded body derived from regenerated cellulose, wherein the degree of polymerization of the regenerated cellulose of the dispersion raw material is 600 or less in claim 8.
A method for manufacturing a cellulose molded body derived from regenerated cellulose, wherein, in the depolymerization process of claim 8 or 9, the degree of polymerization of the ground raw material is reduced by sodium hypochlorite with an effective chlorine concentration of 0.13% or higher.
A method for manufacturing a cellulose molded body derived from regenerated cellulose, wherein, in the depolymerization process of claim 8 or 9, the degree of polymerization of the ground raw material is reduced by sodium hypochlorite with an effective chlorine concentration of 3% or more.
A cellulose molded body obtained by the manufacturing method described in claim 10, wherein the cellulose molded body is a cellulose bead and the average particle diameter (D50) is 50 μm or less, and the cellulose bead is derived from regenerated cellulose.
A cellulose molded body obtained by the manufacturing method described in claim 11, wherein the cellulose molded body is a cellulose bead and the average particle diameter (D50) is 10 μm or less, derived from regenerated cellulose.
A cellulose molded body derived from regenerated cellulose, obtained by the manufacturing method described in claim 10, wherein the molecular weight distribution index (Mw/Mn), obtained by dividing the weight-average molecular weight (Mw) of the cellulose molded body by the number-average molecular weight (Mn), is 3.5 or less.
A cellulose molded body derived from regenerated cellulose, obtained by the manufacturing method described in claim 11, wherein the molecular weight distribution index (Mw/Mn), calculated by dividing the weight-average molecular weight (Mw) of the cellulose molded body by the number-average molecular weight (Mn), is 1.6 or less.

Description

Method for manufacturing a cellulose dispersion derived from regenerated cellulose and a cellulose molded body derived from regenerated cellulose, and a cellulose dispersion derived from regenerated cellulose, cellulose beads derived from regenerated cellulose, and a cellulose molded body derived from regenerated cellulose. The present invention relates to a method for manufacturing a cellulose dispersion derived from regenerated cellulose and a cellulose molded body derived from regenerated cellulose, and to a cellulose dispersion derived from regenerated cellulose, cellulose beads derived from regenerated cellulose, and a cellulose molded body derived from regenerated cellulose. Generally, regenerated cellulose is produced by the viscose method, which involves derivatizing cellulose fibers contained in raw materials such as pulp with chemicals, dissolving them with a solvent to produce viscose, and then coagulating it. The regenerated cellulose obtained in this way is derived from natural materials and possesses properties such as biodegradability, so there is high demand for it as a product. Consequently, it is molded into suitable molded bodies such as fibers, films, and spheres, and processed into various products such as paper products, medical products, and sanitary products. Recently, due to environmental burdens such as wastewater treatment of chemicals used in the viscose method and treatment of exhaust gases generated during the manufacturing process, a method for producing regenerated cellulose by directly dissolving cellulose materials using an ionic liquid without performing the viscose method has been proposed (see, for example, Patent Document 1). This method for producing regenerated cellulose has fewer process steps than the viscose method, which improves work efficiency, and also eliminates the need for exhaust gas treatment performed in the viscose method, thereby reducing the environmental burden. However, with the promotion of the Sustainable Development Goals (SDGs), active efforts are being made across various fields to realize an environmentally conscious circular society. Recycling, which involves reusing discarded products as resources after use, is a well-known example of such environmentally conscious effort. Therefore, there is a demand for the utilization of recycled raw materials in products made from recycled cellulose. However, since regenerated cellulose does not possess thermoplasticity, the methods for dissolving it are limited, making it difficult to recycle. In addition, particularly in cellophane, a film product made from regenerated cellulose, softeners such as glycerin are sometimes contained as additives. Therefore, when cellophane is recycled as a raw material for regenerated cellulose, there is a problem in that the softeners within the cellophane remain in the ionic liquid and cause process abnormalities. For this reason, cellophane was not recycled and was disposed of as waste. FIG. 1 is a schematic process diagram of a method for manufacturing a cellulose dispersion derived from regenerated cellulose and a cellulose molded body according to one embodiment of the present invention. (Form for carrying out the invention) A method (10) for manufacturing a cellulose dispersion derived from regenerated cellulose according to one embodiment of the present invention, as shown in the schematic process diagram of FIG. 1, is a method for manufacturing a cellulose dispersion (11) using regenerated cellulose as a raw material. This method for manufacturing a cellulose dispersion (10) includes a grinding process (S1), a depolymerization process (S2), and a micronization process (S3). In addition, a method (20) for manufacturing a cellulose molded body derived from regenerated cellulose also includes a molding process (S4) to obtain a cellulose molded body (21). Regenerated cellulose is the main raw material (dispersion raw material) of the cellulose dispersion produced by the manufacturing method of the present invention. The lower the degree of polymerization of the regenerated cellulose, the easier it is to defiberize the cellulose, making it easier to process and thereby improving production efficiency. If the degree of polymerization of the regenerated cellulose is excessively high, it becomes difficult to defiberize the cellulose, which may lead to difficulties in manufacturing the cellulose dispersion or the cellulose molded body. For this reason, it is preferable that the degree of polymerization of the regenerated cellulose used as the dispersion raw material be 600 or less. Generally, since the degree of polymerization of regenerated cellulose produced by the viscose method is approximately 200 to 300, it is suitable for use as a raw material for the manufacturing method of the present invention. Furthermore, since the degree of polymerization of the regenerated cellulose obtained by the manufacturing method of regenerated cellulose using a cellulose solvent such a