# US 8,784,611 B2 · Process for production of paper > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,784,611 B2 - Document ID: US8784611B2 - Status: Granted - Kind: B2 - Application number: 13/501,653 - Filed: 2010-11-03 - Published: 2012-09-13 - Granted: 2014-07-22 - Earliest claimed: 2009-11-04 - Assignees: Kemira Oyj - Applicants: Ari Juppo; Ulf Stenbacka - Inventors: Ari Juppo; Ulf Stenbacka - Web page: https://patentgrep.com/patent/US8784611B2 ## CPC - D21H 21/10: Retention agents or drainage improvers - D21H 17/25: Cellulose - D21H 17/37: Polymers of unsaturated acids or derivatives thereof, e.g. polyacrylates - D21H 17/375: {Poly(meth)acrylamide} - D21H 17/44: cationic - D21H 21/52: Additives of definite length or shape - Y10S 977/963: Miscellaneous - 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 - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract The invention relates to a process for the production of paper or board comprising: adding a retention system to a stream of stock entering a paper machine head box, directing the stream of stock to a wire, de watering the stream of stock on the wire to form a paper web, and drying the paper web, wherein the retention system comprises a water-soluble cationic polymer, and nanocellulose acting like a micro particle, wherein the nanocellulose is added in an amount of less than 1% as active substance based on dry solids weight of the stock. ## Claims ### Claim 1 A process for the production of paper or board comprising: adding components of a retention system comprising a water-soluble cationic polymer and nanocellulose acting like a microparticle, sequentially to a stream of stock entering a paper machine headbox, directing the stream of stock to a wire, dewatering the stream of stock on the wire to form a paper web, and drying the paper web, wherein the water-soluble cationic polymer is added to form flocs followed by subjecting the stock to shearing forces to break up the flocs and then adding the nanocellulose, and wherein the nanocellulose is added in an amount of less than 1% as active substance based on dry solids weight of the stock. ### Claim 2 (depends on 1) The process of claim 1, wherein the nanocellulose is added in an amount of between 0.02 and 0.8%, as active substance based on dry solids weight of the stock. ### Claim 3 (depends on 1) The process of claim 1 wherein the nanocellulose is added in the form of an aqueous suspension or gel comprising at most 5% by weight solids. ### Claim 4 (depends on 1) The process of claim 1, wherein the nanocellulose is produced from cellulose pulp by enzymatic treatment followed by homogenization in a high-pressure homogenizer. ### Claim 5 (depends on 1) The process of claim 1, wherein the nanocellulose is produced from cellulose pulp by chemical pre-treatment followed by homogenization in a high-pressure fluidizer. ### Claim 6 (depends on 1) The process of claim 1, wherein the time between the addition of the water-soluble cationic polymer and the nanocellulose is at most 60 seconds. ### Claim 7 (depends on 1) The process of claim 1, wherein the cationic polymer comprises a copolymer of acrylamide or methacrylamide and a cationic monomer. ### Claim 8 (depends on 1) The process of claim 1, wherein the molecular weight of the cationic polymer is at least 500,000. ### Claim 9 (depends on 1) The process of claim 1, wherein the cationic polymer is added in an amount of at least 0.02% as active substance based on dry solids weight of the stock. ### Claim 10 (depends on 1) The process of claim 1, wherein the stock contains chemical pulp, chemimechanical pulp, mechanical pulp or recycled fiber, or various combinations of these. ### Claim 11 (depends on 1) The process of claim 1, wherein the stock additionally comprises a filler and additives commonly used in the production of paper. ### Claim 12 (depends on 1) The process of claim 1, wherein the nanocellulose is added in an amount of between 0.05 and 0.7% as active substance based on dry solids weight of the stock. ### Claim 13 (depends on 1) The process of claim 1, wherein the nanocellulose is added in an amount of between 0.1 and 0.5% as active substance based on dry solids weight of the stock. ### Claim 14 (depends on 1) The process of claim 1, wherein the nanocellulose is added in the form of an aqueous suspension or gel comprising 0.1 to 4% by weight solids. ### Claim 15 (depends on 1) The process of claim 1, wherein the nanocellulose is added in the form of an aqueous suspension or gel comprising from 0.3 to 3% by weight solids. ### Claim 16 (depends on 4) The process of claim 4, wherein the enzyme in the enzymatic treatment comprises a cellulose. ### Claim 17 (depends on 16) The process of claim 16, wherein the cellulose is endoglucanase. ### Claim 18 (depends on 5) The process of claim 5, wherein the chemical pre-treatment comprises carboxymethylation of the fibers. ### Claim 19 (depends on 1) The process of claim 1, wherein the time between the addition of the water-soluble cationic polymer and the nanocellulose is between 0.5 and 20 seconds. ### Claim 20 (depends on 1) The process of claim 1, wherein the cationic polymer is added in an amount of between 0.03 and 0.05% as active substance based on dry solids weight of the stock. ### Claim 21 (depends on 11) The process of claim 11, wherein the filler is ground or precipitated calcium carbonate, kaolin, calcined kaolin, talc, titanium dioxide, gypsum, or a synthetic inorganic or organic filler. ### Claim 22 Use of nanocellulose as a material acting like a microparticle for improving the retention of papermaking raw materials during the production of paper or board, wherein the nanocellulose is used together with a retention aid comprising a water-soluble cationic polymer in such as manner that the nanocellulose is added after the water-soluble cationic polymer, and wherein the nanocellulose is used in an amount of less than 1% as active substance based on dry solids weight of the papermaking stock. ### Claim 23 (depends on 22) The use of claim 22, wherein the nanocellulose is used in an amount of between 0.02 and 0.8% as active substance based on dry solids weight of the stock. ### Claim 24 (depends on 22) The use of claim 22, wherein the nanocellulose is used in an amount of between 0.05 and 0.7% as active substance based on dry solids weight of the stock. ### Claim 25 (depends on 22) The use of claim 22, wherein the nanocellulose is used in an amount of between 0.1 and 0.5% as active substance based on dry solids weight of the stock.