# US 7,608,644 B2 · Aqueous silica-containing composition > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,608,644 B2 - Document ID: US7608644B2 - Status: Granted - Kind: B2 - Application number: 11/129,251 - Filed: 2005-05-13 - Published: 2005-09-22 - Granted: 2009-10-27 - Earliest claimed: 2001-12-21 - Assignees: Akzo Nobel N.V. - Inventors: Johan Nyander; Hans Johansson-Vestin; Jan Nordin; Annika Viola Pal - Web page: https://patentgrep.com/patent/US7608644B2 ## CPC - D21H 17/74: {of organic and inorganic material} - D21H 23/765: {Addition of all compounds to the pulp} - D21H 17/47: Condensation polymers of aldehydes or ketones - D21H 17/68: siliceous, e.g. clays - D21H 21/10: Retention agents or drainage improvers - 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 ## Abstract The present invention refers to a process for the production of paper from a suspension containing cellulosic fibers, and optionally fillers, comprising adding to the suspension at least one cationic organic polymer and an aqueous silica-containing composition comprising an anionic naphthalene sulphonate formaldehyde condensate and anionic silica-based particles, the composition having a weight ratio of naphthalene sulphonate formaldehyde condensate to silica-based particles within the range of from 0.2:1 to 99:1, and containing naphthalene sulphonate formaldehyde condensate and silica-based particles in an amount of at least 0.01% by weight, based on the total weight of the aqueous silica-containing composition, and with the proviso that the composition contains substantially no cellulose-reactive sizing agent. The invention also encompasses an aqueous silica-containing composition and a method for preparation of an aqueous silica-containing compound. ## Claims ### Claim 1 An aqueous silica-containing composition comprising an anionic naphthalene sulphonate formaldehyde condensate and aggregated or microgel formed anionic silica-based particles, wherein the composition has a weight ratio of naphthalene sulphonate formaldehyde condensate to total amount of silica-based particles within the range of from 0.2:1 to 99:1, and wherein the amount of naphthalene sulphonate formaldehyde condensate and total amount of silica-based particles is at least 0.01% by weight, based on the total weight of the aqueous silica-containing composition, and with the provisos that the composition contains substantially no cellulose-reactive sizing agent and the composition is not a cellulosic papermaking stock, wherein the anionic naphthalene sulphonate formaldehyde condensate has a conductivity of less than 15 mS/cm measured at an anionic naphthalene sulphonate formaldehyde condensate content of 10% by weight. ### Claim 2 (depends on 1) The aqueous silica-containing composition according to claim 1 wherein the aqueous silica-containing composition has a weight ratio of naphthalene sulphonate formaldehyde condensate to total amount of silica-based particles within the range of from 0.2:1 to 90:1. ### Claim 3 (depends on 2) The aqueous silica-containing composition according to claim 2 wherein the silica-based particles have a specific surface area within the range of from 300 to 1300 m2/g. ### Claim 4 (depends on 2) The aqueous silica-containing composition according to claim 2 wherein the weight ratio of naphthalene sulphonate formaldehyde condensate to total amount of silica-based particles within the range of from 0.25:1 to 85:1. ### Claim 5 (depends on 1) The aqueous silica-containing composition according to claim 1 wherein the silica-based particles have a specific surface area within the range of from 300 to 1300 m2/g. ### Claim 6 (depends on 1) The aqueous silica-containing composition according to claim 1 wherein the composition is an additive for a cellulosic papermaking stock. ### Claim 7 (depends on 1) The aqueous silica-containing composition according to claim 1 wherein the composition is a flocculation agent for treating water. ### Claim 8 A method for the preparation of an aqueous silica-containing composition which comprises mixing an aqueous anionic naphthalene sulphonate formaldehyde condensate solution having a conductivity less than 15 mS/cm with an aqueous alkali stabilised sol containing silica-based particles wherein the prepared aqueous silica-containing composition contains naphthalene sulphonate formaldehyde condensate and total amount of silica-based particles in an amount of at least 0.01% by, weight, wherein the conductivity is measured at an anionic naphthalene sulphonate formaldehyde condensate content of 10% by weight. ### Claim 9 (depends on 8) The method according to claim 8 wherein the aqueous silica-containing composition has a weight ratio of naphthalene sulphonate formaldehyde condensate to total amount of silica-based particles within the range of from 0.2:1 to 90:1. ### Claim 10 (depends on 9) The method according to claim 9 wherein the weight ratio of naphthalene sulphonate formaldehyde condensate to total amount of silica-based particles within the range of from 0.25:1 to 85:1. ### Claim 11 (depends on 8) The method according to claim 8 wherein the silica-based particles have a specific surface area within the range of from 300 to 1300 m2/g. ### Claim 12 (depends on 8) The method according to claim 8 wherein the silica-based particles have an S-value within the range of from 5 to 50% prior to mixing with the anionic of naphthalene sulphonate formaldehyde condensate. ### Claim 13 (depends on 8) The method according to claim 8 wherein the silica-based particles have an S-value within the range of from 8 to 45% prior to mixing with the anionic of naphthalene sulphonate formaldehyde condensate. ### Claim 14 (depends on 8) The method according to claim 8 wherein it further comprises desalinating the aqueous anionic naphthalene sulphonate formaldehyde condensate solution prior to mixing it with the aqueous alkali stabilised sol containing silica-based particles. ### Claim 15 An aqueous silica-containing composition comprising an anionic naphthalene sulphonate formaldehyde condensate and aggregated or microgel formed anionic silica-based particles, wherein the composition has a weight ratio of naphthalene sulphonate formaldehyde condensate to total amount of silica-based particles within the range of from 0.2:1 to 99:1, and wherein the amount of naphthalene sulphonate formaldehyde condensate and total amount of silica-based particles is at least 0.5 % by weight, based on the total weight of the aqueous silica-containing composition, and with the proviso that the composition contains substantially no cellulose-reactive sizing agent, wherein the anionic naphthalene sulphonate formaldehyde condensate has a conductivity of less than 15 mS/cm measured at an anionic naphthalene sulphonate formaldehyde condensate content of 10% by weight. ### Claim 16 (depends on 15) The aqueous silica-containing composition according to claim 15 wherein the amount of naphthalene sulphonate formaldehyde condensate and total amount of silica-based particles is in the range of 1 to 45% by weight, based on the total weight of the aqueous silica-containing composition. ### Claim 17 (depends on 16) The aqueous silica-containing composition according to claim 16 wherein the amount of naphthalene sulphonate formaldehyde condensate and total amount of silica-based particles is in the range of 2 to 35% by weight, based on the total weight of the aqueous silica-containing composition. ### Claim 18 (depends on 17) The aqueous silica-containing composition according to claim 17 wherein the amount of naphthalene sulphonate formaldehyde condensate and total amount of silica-based particles is in the range of 5 to 30% by weight, based on the total weight of the aqueous silica-containing composition.