# US 9,752,282 B2 · Method for producing nanofibrillar cellulose > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,752,282 B2 - Document ID: US9752282B2 - Status: Granted - Kind: B2 - Application number: 14/440,255 - Filed: 2013-11-01 - Published: 2015-10-22 - Granted: 2017-09-05 - Earliest claimed: 2012-11-03 - Assignees: Upm-Kymmene Corporation - Applicants: Upm-Kymmene Corporation - Inventors: Antti Laukkanen; Markus Nuopponen - Web page: https://patentgrep.com/patent/US9752282B2 ## CPC - D21H 11/18: Highly hydrated, swollen or fibrillatable fibres - C08B 15/00: Preparation of other cellulose derivatives or modified cellulose {, e.g. complexes} - C08B 15/02: Oxycellulose; Hydrocellulose; {Cellulosehydrate, e.g. microcrystalline cellulose} - C08B 15/04: Carboxycellulose, e.g. prepared by oxidation with nitrogen dioxide - C08L 1/04: Oxycellulose; Hydrocellulose {, e.g. microcrystalline cellulose} - D21B 1/021: {by chemical means} - D21C 9/007: {by mechanical or physical means} - D21H 11/16: modified by a particular after-treatment - D21H 11/20: Chemically or biochemically modified fibres - 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) - D21B: FIBROUS RAW MATERIALS OR THEIR MECHANICAL TREATMENT - D21C: PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR ## Abstract In a method for preparing nanofibrillar cellulose, fibrous dispersion of ionically charged cellulose is repeatedly passed through a mechanical process of disrupting fibers into fibrils until the viscosity starts to decrease. The number average diameter of the nanofibrillar cellulose after the mechanical process is in the range of 2-10 nm, and the zero-shear viscosity is below 10 Pa·s, preferably below 1 Pa·s, when measured in the concentration of 0.5 wt-%. The nanofibrillated cellulose is low aspect ratio nanofibrillated cellulose (NFC-L). ## Claims ### Claim 1 A method for preparing nanofibrillar cellulose, comprising: repeatedly passing fibrous dispersion of ionically charged cellulose through a mechanical process of disrupting fibers into fibrils until viscosity of the fibrous dispersion starts to decrease, wherein after the mechanical process the nanofibrillar cellulose has a number average diameter in the range of 2-10 nm, and a zero-shear viscosity below 10 Pa·s, when measured in a nanofibrillar cellulose concentration of 0.5 wt-%. ### Claim 2 (depends on 1) The method according to claim 1, wherein the nanofibrillar cellulose has crystalline structure being cellulose I. ### Claim 3 (depends on 1) The method according to claim 1, wherein the nanofibrillar cellulose has amorphous regions. ### Claim 4 (depends on 1) The method according to claim 1, wherein the nanofibrillar cellulose has a number average length below 1 micrometer. ### Claim 5 (depends on 1) The method according to claim 1, wherein the nanofibrillar cellulose has an average aspect ratio in the range of 80-300. ### Claim 6 (depends on 1) The method according to claim 1, wherein the method further comprises oxidizing cellulose through N-oxyl mediated catalytic oxidation to obtain oxidized cellulose. ### Claim 7 (depends on 6) The method according to claim 6, wherein the oxidized cellulose has a carboxylate content of at least 0.75 mmol COOH/g pulp. ### Claim 8 (depends on 1) The method according to claim 1, wherein the mechanical process of disrupting fibers into fibrils is performed by passing fibrous dispersion through a high pressure homogenizer or fluidizer. ### Claim 9 (depends on 1) The method according to claim 1, wherein the zero-shear viscosity of the nanofibrillar cellulose is below 1 Pa·s, when measured in the nanofibrillar cellulose concentration of 0.5 wt-%. ### Claim 10 (depends on 9) The method according to claim 9, wherein the nanofibrillar cellulose has crystalline structure being cellulose I. ### Claim 11 (depends on 9) The method according to claim 9, wherein the nanofibrillar cellulose has amorphous regions. ### Claim 12 (depends on 10) The method according to claim 10, wherein the nanofibrillar cellulose has amorphous regions. ### Claim 13 (depends on 1) The method according to claim 1, wherein the nanofibrillar cellulose has a number average length below 500 nm. ### Claim 14 (depends on 1) The method according to claim 1, wherein the nanofibrillar cellulose has an average aspect ratio in the range of 100-250 nm. ### Claim 15 (depends on 6) The method according to claim 6, wherein the oxidized cellulose has a carboxylate content of 0.8-1.2 mmol COOH/g pulp. ### Claim 16 (depends on 6) The method according to claim 6, wherein the oxidized cellulose has a carboxylate content of 0.9-1.1 mmol COOH/g pulp. ### Claim 17 (depends on 9) The method according to claim 9, wherein the nanofibrillar cellulose has a number average length below 1 micrometer. ### Claim 18 (depends on 9) The method according to claim 9, wherein the nanofibrillar cellulose has a number average length below 500 nm. ### Claim 19 (depends on 9) The method according to claim 9, wherein the nanofibrillar cellulose has an average aspect ratio in the range of 80-300 nm. ### Claim 20 (depends on 9) The method according to claim 9, wherein the nanofibrillar cellulose has an average aspect ratio in the range of 100-250 nm. ### Claim 21 (depends on 9) The method according to claim 9, wherein the method further comprises oxidizing cellulose through N-oxyl mediated catalytic oxidation to obtain oxidized cellulose. ### Claim 22 (depends on 21) The method according to claim 21, wherein the oxidized cellulose has a carboxylate content of at least 0.75 mmol COOH/g pulp. ### Claim 23 (depends on 21) The method according to claim 21, wherein the oxidized cellulose has a carboxylate content of 0.8-1.2 mmol COOH/g pulp. ### Claim 24 (depends on 21) The method according to claim 21, wherein the oxidized cellulose has a carboxylate content of 0.9-1.1 mmol COOH/g pulp. ### Claim 25 (depends on 9) The method according to claim 9, wherein the mechanical process of disrupting fibers into fibrils is performed by passing fibrous dispersion through a high pressure homogenizer or fluidizer. ### Claim 26 (depends on 1) Nanofibrillar cellulose obtainable by the method for preparing nanofibrillar cellulose according to claim 1, wherein the nanofibrillar cellulose has a number average diameter in the range of 2-10 nm, and a zero-shear viscosity below 1 Pa·s, when measured in a nanofibrillar cellulose concentration of 0.5 wt-%. ### Claim 27 (depends on 26) The nanofibrillar cellulose according to claim 26, wherein the nanofibrillar cellulose has crystalline structure being cellulose I. ### Claim 28 (depends on 26) The nanofibrillar cellulose according to claim 26, wherein the nanofibrillar cellulose has amorphous regions. ### Claim 29 A method of using nanofibrillar cellulose comprising: providing nanofibrillar cellulose having a number average diameter in the range of 2-10 nm, and a zero-shear viscosity below 1 Pa·s, when measured in a nanofibrillar cellulose concentration of 0.5 wt-%, and using the nanofibrillar cellulose in pickering stabilization. ### Claim 30 (depends on 29) The method according to claim 29, wherein the nanofibrillar cellulose is used in foam stabilization. ### Claim 31 (depends on 30) The method according to claim 30, wherein the nanofibrillar cellulose is used in foam forming for making fibrous sheet-like products. ### Claim 32 (depends on 29) The method according to claim 29, wherein the nanofibrillar cellulose has crystalline structure being cellulose I. ### Claim 33 (depends on 29) The method according to claim 29, wherein the nanofibrillar cellulose has amorphous regions. ### Claim 34 (depends on 32) The method according to claim 32, wherein the nanofibrillar cellulose has amorphous regions.