US-12617938-B2 - Fibrillated fiber and method for preparing the same

US12617938B2US 12617938 B2US12617938 B2US 12617938B2US-12617938-B2

Abstract

The present disclosure relates to fibrillated fibers and a method for preparing the same. In the present disclosure, there is provided a preparation method capable of providing fibers suitable for complexing with plastics in a more simplified process. According to the preparation method of the present disclosure, microfibers can be easily miniaturized with little energy by growing fine particles on the microfibers to fibrillate the microfibers, and then applying a shear force thereto, and various physical properties can be expressed from the grown fine particles.

Inventors

Minsung PARK
Su Hee LEE
Nana Kang
Kwang Seoung JEON

Assignees

LG CHEM, LTD.

Dates

Publication Date: 20260505
Application Date: 20210531
Priority Date: 20200529

Claims (8)

1 . A method for preparing fibrillated fibers, the method comprising the steps of: preparing a mixture comprising microfibers, a fine particle precursor, and a solvent; fibrillating the microfibers by growing fine particles on the microfibers from the fine particle precursor by adding a reducing agent, a catalyst, a ligand or a mixture thereof to the mixture and then stirring; and miniaturizing the microfibers by applying a shear force to the microfibers fibrillated by the growth of the fine particles, wherein the microfibers are cellulose fibers, the microfibers fibrillated by the growth of the fine particles contain microcellulose fibers comprising nanofibrils and the fine particles, the nanofibrils are bonded to a surface of the microcellulose fibers, and the fine particles are bonded to the nanofibrils or bonded to a surface or inside of the microcellulose fibers, and the mixture comprises 40 to 100 parts by weight of the fine particle precursor and 1000 to 10000 parts by weight of the solvent based on 100 parts by weight of the microfibers, wherein in the step of preparing the mixture, the microfibers are added after dissolving the fine particle precursor in the solvent.
2 . The method for preparing fibrillated fibers of claim 1 , wherein the fine particle precursor comprises an acetate, chloride, or nitrate of at least one metal selected from the group consisting of copper, zinc, calcium, aluminum, iron, platinum, palladium, ruthenium, iridium, rhodium, osmium, chromium, cobalt, nickel, manganese, vanadium, molybdenum, and gallium; or a silicon oxide precursor.
3 . The method for preparing fibrillated fibers of claim 1 , wherein the solvent is water, alcohol, dimethyl sulfoxide, sodium hydroxide solution, ammonia solution, urea solution, or a mixture thereof.
4 . The method for preparing fibrillated fibers of claim 1 , wherein in the step of fibrillating the microfibers, the fine particles grown on the microfibers from the fine particle precursor have a minor axis diameter of 0.01 μm to 10 μm.
5 . The method for preparing fibrillated fibers of claim 1 , wherein the microcellulose fibers have a minor axis diameter of 1 μm to 30 μm, and the nanofibrils have a minor axis diameter of 10 nm to 400 nm.
6 . The method for preparing fibrillated fibers of claim 1 , further comprising a step of modifying the fine particles by adding a lipophilic compound having a thiol group after growing the fine particles on the microfibers.
7 . The method for preparing fibrillated fibers of claim 6 , wherein the lipophilic compound having a thiol group is 1-decanethiol, 1-undecanethiol, 1-dodecanethiol, 1-tetradecanethiol, 1-pentadecanethiol, 1-hexadecanethiol, or 1-octadecanethiol.
8 . The method for preparing fibrillated fibers of claim 1 , wherein the reducing agent is sodium hydroxide, a metal hydride-based reducing agent, a borohydride-based reducing agent, a borane-based reducing agent, a silane-based reducing agent, a hydrazine-based reducing agent, or a hydrazide-based reducing agent, the catalyst is ammonia or urea, and the ligand is benzene-1,3,5-tricarboxylate (BTC).

Description

CROSS-REFERENCE TO RELATED APPLICATION(S) The present application is a national stage entry under 35 U.S.C. § 371 of International Application No. PCT/KR2021/006738 filed on May 31, 2021, which claims priority from Korean Patent Applications No. 10-2020-0065204 filed on May 29, 2020, No. 10-2020-0086346 filed on Jul. 13, 2020, No. 10-2021-0069785 filed on May 31, 2021, No. 10-2021-0069786 filed on May 31, 2021, and No. 10-2021-0069787 filed on May 31, 2021, all the disclosures of which are incorporated herein by reference. TECHNICAL FIELD The present disclosure relates to fibrillated fibers and a method for preparing the same. BACKGROUND OF ART Cellulose is attracting attention as a polymer material with excellent mechanical properties and biodegradability. As part of this, research to provide an eco-friendly complex by complexing cellulose and plastics is in the spotlight. However, in order to complex cellulose with plastics, complex and expensive pretreatment processes such as a solvent replacement process for changing the solvent of cellulose extract from water to an organic solvent and a modification process for imparting lipophilicity to highly hydrophilic cellulose are required. In order to simplify the process, attempts have been made to modify and miniaturize the cellulose by applying a physical force to the untreated pulp-state cellulose. However, since the cellulose is strongly connected by hydrogen bonds in its chemical structure, there is a limitation in miniaturizing the pulp-state cellulose only by the physical force. In addition, it is difficult to sufficiently modify the pulp-state cellulose. In addition, methods for introducing inorganic particles or introducing a separate organic group to the surface of cellulose nanofibers in order to ensure compatibility with the polymer complex are known. However, since the surface-modified cellulose nanofibers are easily aggregated in the polymer complex, it is very difficult to disperse them in the nanoscale, and thus there is a limitation in obtaining a sufficient reinforcing effect. Accordingly, there is still a need for a method capable of providing cellulose suitable for complexing with plastics in a more simplified process. DETAILED DESCRIPTION OF THE INVENTION Technical Problem In the present disclosure, there is provided a method for preparing fibrillated fibers which can provide fibers suitable for complexing with plastics in a more simplified process. In the present disclosure, there is also provided fibrillated fibers capable of exhibiting excellent dispersibility in the complex with plastics. Technical Solution Hereinafter, the fibrillated fibers and the method for preparing the same according to embodiments of the present invention will be described. The terms are used merely to refer to specific embodiments, and are not intended to restrict the present disclosure unless it is explicitly expressed. Singular expressions of the present disclosure may include plural expressions unless they are differently expressed contextually. The terms “include”, “comprise”, and the like of the present disclosure are used to specify certain features, regions, integers, steps, operations, elements, and/or components, and these do not exclude the existence or the addition of other certain features, regions, integers, steps, operations, elements, and/or components. As used herein, ‘nanofiber’ or ‘nanofibrils’ refers to a fiber having a minor axis diameter in the nanometer range, and ‘microfiber’ refers to a fiber having a minor axis diameter in the micrometer range. For example, the microfiber may be composed of a bundle of the nanofibers. As used herein, ‘pulp’ refers to a lignocellulosic fibrous material obtained by chemically or mechanically separating cellulose fibers from wood, fiber crops, waste paper, rags, or the like. As used herein, ‘pulp fiber’, ‘cellulose fiber’ or ‘microcellulose fiber’ refers to a microfiber made of cellulose. As used herein, ‘cellulose nanofiber’ refers to a nanofiber made of cellulose. As used herein, ‘fibrillation’ refers to a phenomenon in which nanofibrils forming the internal structure of cellulose fibers are released and raised like fluff on the cellulose fibers. As used herein, ‘fibrillated cellulose fiber’ refers to a cellulose fiber in a state in which nanofibrils having a minor axis diameter in the nanometer range are raised like fluff on the cellulose fiber by the fibrillation. I. The Method for Preparing Fibrillated Fibers According to an embodiment of the present disclosure, there is provided a method for preparing fibrillated fibers including the steps of: preparing a mixture containing microfibers, a fine particle precursor, and a solvent;fibrillating the microfibers by growing fine particles on the microfibers from the fine particle precursor; andminiaturizing the microfibers by applying a shear force to the microfibers fibrillated by the growth of the fine particles. First, a step of preparing a mixture contain