# US 2019/0169797 A1 · Method of producing a carboxyalkylated nfc product, a carboxyalkylated nfc product and use thereof

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- Number: US 2019/0169797 A1
- Document ID: US20190169797A1
- Status: Published application
- Kind: A1
- Application number: 16/316,758
- Filed: 2017-06-20
- Published: 2019-06-06
- Earliest claimed: 2016-07-15
- Applicants: Rise Innventia AB
- Inventors: Ali NADERI
- Web page: https://patentgrep.com/patent/US20190169797A1

## CPC

- D21H 11/18: Highly hydrated, swollen or fibrillatable fibres
- C08B 11/12: substituted with carboxylic radicals {, e.g. carboxymethylcellulose [CMC]}
- C08L 1/02: Cellulose; Modified cellulose
- C08L 1/286: {substituted with acid radicals, e.g. carboxymethyl cellulose [CMC] (C08L1/282 takes precedence)}
- D21C 9/002: {by chemical means; preparation of dewatered pulp, e.g. in sheet or bulk form, containing special additives}
- D21C 9/004: {inorganic compounds}
- D21C 9/005: {organic compounds}
- D21C 9/007: {by mechanical or physical means}
- D21H 21/06: Paper forming aids
- D21H: PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- C08B: POLYSACCHARIDES; DERIVATIVES THEREOF (polysaccharides containing less than six saccharide radicals attached to each other by glycosidic linkages C07H; fermentation or enzyme-using processes C12P19/00; sugar industry C13; production of cellulose D21)
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)
- D21C: PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR

## Abstract

The present invention relates to a method of producing a nanofibrillated cellulose (NFC), the nanofibrillated cellulose product obtained and the use of the nanofibrillated cellulose product. The method comprises the steps of: Providing cellulosic fibres dispersed in water; Solvent-exchanging water in the fibres to an organic solvent, such as alcohol, suitably ethanol or isopropanol; Impregnating the fibres with a solution comprising a halogenated aliphatic acid having more than 2 carbon atoms; Heat-treating the impregnated fibres at a temperature of more than 50° C. in an alkaline solution comprising an organic solvent, which solution is optionally aqueous, to carboxyalkylatethe fibres; Washing the fibres; Converting the carboxyl groups their alkali metal counter-ion form; Optionally filtering the fibres; Dispersing the fibres in water; Mechanically disintegrating the fibres to provide the NFC product.

## Claims

### Claim 1

A method of producing a nanofibrillated cellulose (NFC) product comprising the steps of:
i) Providing cellulosic fibres dispersed in water;
ii) Solvent-exchanging water in the fibres to an organic solvent;
iii) Impregnating the fibres with a solution comprising a halogenated aliphatic acid having more than 2 carbon atoms;
iv) Heat-treating the impregnated fibres at a temperature of more than 50° C. in an alkaline solution comprising an organic solvent to carboxyalkylate the fibres;
v) Washing the fibres;
vi) Converting the carboxyl groups to their alkali metal counter-ion form;
vii) Optionally filtering the fibres;
viii) Dispersing the fibres in water; and
ix) Mechanically disintegrating the fibres to provide the NFC product.

### Claim 2 (depends on 1)

The method according to claim 1, wherein the halogenated aliphatic acid is 2-chloropropionic acid.

### Claim 3 (depends on 1)

The method according to claim 1, wherein the alkaline solution in step iv) is obtained by the use of sodium hydroxide.

### Claim 4 (depends on 1)

The method according to claim 1, wherein the organic solvent in the alkaline solution in step iv) comprises at least one of methanol, ethanol and isopropanol or any mixture thereof.

### Claim 5 (depends on 1)

The method according to claim 1, wherein the washing in step v) is performed in three steps comprising at least one step of washing in water and at least one step of washing in a solution comprising an organic acid.

### Claim 6 (depends on 1)

The method according to claim 1, wherein the alkali metal counter-ion form of the carboxyl group comprises sodium.

### Claim 7 (depends on 6)

The method according to claim 6, wherein the total charge of the fibres and/or the NFC product is from 600-700 μeq/g, determined by means of conductometric titration.

### Claim 8 (depends on 6)

The method according to claim 6, wherein the degree of substitution of the fibres is from 0.1 to 0.3.

### Claim 9 (depends on 1)

The method according to claim 1, wherein after the step ix), fibres in the NFC product have a fibre diameter of about 3 to 100 nm.

### Claim 10 (depends on 1)

The method according to claim 1, wherein after the step ix) the dry-content of the NFC-product obtained in step ix) is from 0.05 to 10% by weight.

### Claim 11 (depends on 1)

The method according to claim 1, wherein the method further comprises:
x) Drying the NFC-product to provide a concentrated or dried NFC-product.

### Claim 12 (depends on 11)

The method according to claim 11, wherein the method further comprises:
xi) Re-dispersing the dried NFC-product in an aqueous solution.

### Claim 13 (depends on 1)

An NFC-product obtained by the method according to claim 1.

### Claim 14 (depends on 13)

A product comprising the NFC-product according to claim 13, wherein the product comprises a cosmetic product, a pharmaceutical product, a food product, a paper product, a composite material, a coating, a hygiene/absorbent product, a film, an emulsion/dispersing agent, or a drilling mud.

### Claim 15 (depends on 13)

A composition for enhancing reactivity of cellulose in the manufacture of regenerated cellulose or a cellulose derivative, the composition comprising the NFC-product according to claim 13 and one or more of regenerated cellulose or a cellulose derivative.

### Claim 16 (depends on 13)

A composition comprising the NFC-product according to claim 13 and a rheology modifier.