Cellulose microfibers and method for manufacturing the same

Patent metadata

Field	Value
Publication number	US-10975518-B2
Application number	US-201816485713-A
Country	US
Kind code	B2
Filing date	Feb 23, 2018
Priority date	Feb 28, 2017
Publication date	Apr 13, 2021
Grant date	Apr 13, 2021

Abstract

As to a method for manufacturing cellulose microfibers, cellulose fibers are added with an additive (A) consisting of at least one of a phosphorous acid and a metal phosphite and an additive (B) consisting of at least one of urea and a urea derivative, heated and washed, then fibrillated. Also, as to cellulose microfibers, the fiber width is 1 to 1000 nm, and a part of hydroxy groups of cellulose fibers is substituted with a functional group represented by a predetermined structural formula to introduce an ester of phosphorous acid.

First claim

The invention claimed is:

1. A method for manufacturing cellulose microfibers comprising:
providing cellulose fibers having a plurality of hydroxy groups,
adding an additive (A) consisting of at least one of a phosphorous acid and a metal phosphite and an additive (B) consisting of at least one of urea and a urea derivative to the cellulose fibers;
heating and washing the cellulose fibers to which the additive (A) and the additive (B) have been added such that an ester of phosphorous acid is introduced; and
fibrillating the cellulose fibers;
wherein the heating is performed until a degree of substitution of the plurality of hydroxy groups in the cellulose fibers ranges from 0.01 to 0.55, wherein the degree of substitution is an average number of substitutions of the plurality of hydroxy groups with respect to one glucose unit in the cellulose fibers.

2. The method for manufacturing cellulose microfibers according to claim 1 , wherein the heating is performed until the moisture content is 10% or less.

3. The method for manufacturing cellulose microfibers according to claim 1 , wherein the addition amount of the additive (A) is 1 to 10,000 g based on 1 kg of the cellulose fibers, and the addition amount of the additive (B) is 0.01 to 100 mol based on 1 mol of the additive (A).

4. The method for manufacturing cellulose microfibers according to claim 1 , wherein the heating is performed at 100 to 210° C.

5. The method for manufacturing cellulose microfibers according to claim 1 , wherein the heating is performed at a pH of 3 to 12.

6. Cellulose microfibers, wherein a fiber width is 1 to 1000 nm, and a part of a plurality of hydroxy groups of cellulose fibers is substituted with a functional group represented by the following structural formula (1) to introduce an ester of phosphorous acid:

where α is any of none, R, and NHR, R is any of a hydrogen atom, a saturated-linear hydrocarbon group, a saturated-branched hydrocarbon group, a saturated-cyclic hydrocarbon group, an unsaturated-linear hydrocarbon group, an unsaturated-branched hydrocarbon group, an aromatic group, and derivative groups thereof, and β is a cation consisting of an organic substance or an inorganic substance; and
wherein a degree of substitution of the plurality of hydroxy groups in the cellulose fibers by the functional group represented by the structural formula (1) ranges from 0.01 to 0.55, wherein the degree of substitution is an average number of substitutions of the functional group represented by the structural formula (1) with respect to one glucose unit in the cellulose fibers.

7. The cellulose microfibers according to claim 6 , wherein a part of hydroxy groups of cellulose fibers is substituted with a carbamate group to introduce a carbamate.

8. The method for manufacturing cellulose microfibers according to claim 2 , wherein the addition amount of the additive (A) is 1 to 10,000 g based on 1 kg of the cellulose fibers, and the addition amount of the additive (B) is 0.01 to 100 mol based on 1 mol of the additive (A).

9. The method for manufacturing cellulose microfibers according to claim 2 , wherein the heating is performed at 100 to 210° C.

10. The method for manufacturing cellulose microfibers according to claim 3 , wherein the heating is performed at 100 to 210° C.

11. The method for manufacturing cellulose microfibers according to claim 2 , wherein the heating is performed at a pH of 3 to 12.

12. The method for manufacturing cellulose microfibers according to claim 3 , wherein the heating is performed at a pH of 3 to 12.

13. The method for manufacturing cellulose microfibers according to claim 4 , wherein the heating is performed at a pH of 3 to 12.

Assignees

• Daio Seishi Kk

Inventors

• Matsusue Ikko

Classifications

• D21H15/02

  characterised by configuration · CPC title

• D21H11/18 Primary

  Highly hydrated, swollen or fibrillatable fibres · CPC title

• D21C9/007

  by mechanical or physical means · CPC title

• D21C9/002 Primary

  by chemical means; preparation of dewatered pulp, e.g. in sheet or bulk form, containing special additives · CPC title

• C08B15/06

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