Fine cellulose fiber, production method thereof, slurry, and composite

Patent metadata

Field	Value
Publication number	US-11655310-B2
Application number	US-201816622475-A
Country	US
Kind code	B2
Filing date	Jun 13, 2018
Priority date	Jun 14, 2017
Publication date	May 23, 2023
Grant date	May 23, 2023

Abstract

Provided are: a fine cellulose fiber that is superior in handling properties and that can suitably be used as a reinforcing material or the like for resin; a production method of the fine cellulose fiber; and a slurry and a composite comprising the fine cellulose fibers. The present invention pertains to fine cellulose fibers comprising a carbamate group. The degree of substitution with the carbamate group with respect to hydroxy groups in the fine cellulose fibers is preferably no less than 0.05 and no greater than 0.5. The present invention pertains to a slurry comprising the fine cellulose fibers, to a composite comprising the fine cellulose fibers and a resin, and to a production method of the fine cellulose fibers, comprising performing a heat treatment on a mixture of a plant raw material and urea or the like, and performing a miniaturization treatment of the plant raw material.

First claim

The invention claimed is:

1. A fine cellulose fiber comprising a carbamate group,
wherein the carbamate group is a group represented by —O—CO—NH2, —O—CO—NHR, or —O—CO—NR2, wherein R each independently represents a saturated linear hydrocarbon group, a saturated branched-chain hydrocarbon group, a saturated cyclic hydrocarbon group, an unsaturated linear hydrocarbon group, an unsaturated branched-chain hydrocarbon group, an aromatic group, or a group derived therefrom,
wherein the fine cellulose fiber is obtained by defibrating a plant raw material; and
an average fiber diameter of the fine cellulose fiber is 2 nm to 10 μm, and an average length of the fine cellulose fiber is no less than 1 μm and no greater than 5,000 μm,
a zeta potential is no less than −100 and no greater than −30 mV,
a freeness is no greater than 100 cc,
a pulp viscosity is no less than 2 and no greater than 15 cP,
the fine cellulose fiber exhibits a single peak on a pseudo particle size distribution curve obtained by a measurement with a laser diffraction method in a state of having been dispersed in water, a particle diameter of the fine cellulose fiber with the single peak being no less than 5 and no greater than 50 μm, and
a degree of substitution with the carbamate group with respect to hydroxy groups is no less than 0.05 and no greater than 0.5.

2. A slurry comprising the fine cellulose fiber according to claim 1 .

3. A composite comprising a resin and the fine cellulose fiber according to claim 1 .

4. A production method of a fine cellulose fiber comprising a carbamate group, the method comprising:
mixing a plant raw material and urea or a urea derivative in a dispersion medium to obtain a dispersion liquid;
removing the dispersion medium by heating the dispersion liquid to obtain a mixture of the plant raw material and the urea or the urea derivative;
performing a heat treatment on the mixture; and
performing a miniaturization treatment of the plant raw material in the mixture subjected to the heat treatment, the fine cellulose fiber is obtained by defibrating the plant raw material;
wherein the carbamate group is a group represented by —O—CO—NH2, —O—CO—NHR, or —O—CO—NR2, wherein R each independently represents a saturated linear hydrocarbon group, a saturated branched-chain hydrocarbon group, a saturated cyclic hydrocarbon group, an unsaturated linear hydrocarbon group, an unsaturated branched-chain hydrocarbon group, an aromatic group, or a group derived therefrom,
a average fiber diameter of the fine cellulose fiber is 2 nm to 10 μm, and a average length of the fine cellulose fiber is no less than 1 μm and no greater than 5,000 μm,
a zeta potential is no less than −100 and no greater than −30 mV,
a freeness is no greater than 100 cc,
a pulp viscosity is no less than 2 and no greater than 15 cP,
the fine cellulose fiber exhibits a single peak on a pseudo particle size distribution curve obtained by a measurement with a laser diffraction method in a state of having been dispersed in water, a particle diameter of the fine cellulose fiber with the single peak being no less than 5 and no greater than 50 μm, and
a degree of substitution with the carbamate group with respect to hydroxy groups is no less than 0.05 and no greater than 0.5.

5. The production method of a fine cellulose fiber according to claim 4 , wherein the heat treatment is performed at no less than 120° C. and no greater than 200° C.

6. The production method of a fine cellulose fiber according to claim 4 , wherein the heat treatment is performed under an acidic condition.

7. The production method of a fine cellulose fiber according to claim 4 , wherein the fine cellulose fiber is used as a reinforcing material for a resin.

Assignees

• Univ Kyoto
• Daio Seishi Kk

Inventors

• Tsujii Yoshinobu
• Sakakibara Keita
• Tanaka Koji
• Ikuma Takahito
• Okawa Junya
• Matsusue Ikko

Classifications

• D06M2101/06

  cellulosic · CPC title

• C08B1/003

  Preparation of cellulose solutions, i.e. dopes, with different possible solvents, e.g. ionic liquids (solutions used in the manufacture of monocomponent artificial filaments or cellulose or derivatives thereof D01F2/02) · CPC title

• D06M13/432

  Urea, thiourea or derivatives thereof, e.g. biurets; Urea-inclusion compounds; Dicyanamides; {Carbodiimides;} Guanidines, e.g. dicyandiamides · CPC title

• C08B15/06 Primary

  containing nitrogen {, e.g. carbamates} · CPC title

• C08L1/08

  Cellulose derivatives · CPC title