# US 2021/0340708 A1 · A paper substrate comprising modified low molecular weight pva with functional vinyl groups > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0340708 A1 - Document ID: US20210340708A1 - Status: Published application - Kind: A1 - Application number: 17/280,946 - Filed: 2018-10-09 - Published: 2021-11-04 - Earliest claimed: 2018-10-09 - Assignees: Upm-Kymmene Corporation - Applicants: UPM-Kymmene Corporation - Inventors: Harri Kosonen; Mikko Rissanen; Kuisma Littunen; Jaakko Rautalahti; Janne Antila - Web page: https://patentgrep.com/patent/US20210340708A1 ## CPC - C08F 8/48: Isomerisation; Cyclisation - D21H 19/72: Coated paper characterised by the paper substrate - C08F 8/28: Condensation with aldehydes or ketones - C09D 129/14: Homopolymers or copolymers of acetals or ketals obtained by polymerisation of unsaturated acetals or ketals or by after-treatment of polymers of unsaturated alcohols - C09D 183/04: Polysiloxanes - D21H 19/20: comprising macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds - D21H 19/24: comprising macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds - D21H 19/32: obtained by reactions forming a linkage containing silicon in the main chain of the macromolecule - D21H 19/82: superposed {(D21H19/84 takes precedence)} - C08F 216/38: by an acetal or ketal radical - C08F 2810/30: leading to the formation or introduction of aliphatic or alicyclic unsaturated groups - C08G 77/12: containing silicon bound to hydrogen - Y02P 20/582: Recycling of unreacted starting or intermediate materials - C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS - 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 - C09D: COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR (cosmetics A61K; processes for applying liquids or other fluent materials to surfaces, in general, B05D; staining wood B27K5/02; glazes or vitreous enamels C03C; natural resins, French polish, drying-oils, driers, turpentine, per se, C09F; polishing compositions other than French polish, ski waxes C09G; adhesives or use of materials as adhesives C09J; materials for sealing or packing joints or covers C09K3/10; materials for stopping leaks C09K3/12; processes for the electrolytic or electrophoretic production of coatings C25D) - C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract The invention relates to a method for manufacturing a paper substrate suitable for binding silicone in a catalytic hydrosilation reaction and products thereof, wherein the molecular weight of polyvinyl alcohol is used to control the viscosity of the water-based acetalization reaction, such that a paper substrate may be coated with acetalized polyvinyl alcohol that contains high amount of functional vinyl groups, wherein the functional vinyl groups are part of catenated carbon structures which contain at least 4 carbon atoms and which have an acetal connectivity with the backbone chain of the acetalized polyvinyl alcohol. ## Claims ### Claim 1 A paper substrate which is suitable for binding silicone in a catalytic hydrosilation reaction, the paper substrate comprising a cellulose fiber-based support layer and a hydrophobic primer layer that contains acetalized polyvinyl alcohol, wherein the acetalized polyvinyl alcohol has a weight average molecular weight of less than 5000 g/mol, and contains a vinyl group molality which is equal to or higher than 0.2 millimoles per gram of the acetalized polyvinyl alcohol, and wherein the functional vinyl groups are part of catenated carbon structures which contain at least 4 carbon atoms, and which have an acetal connectivity with the backbone chain of the acetalized polyvinyl alcohol. ### Claim 2 A method for manufacturing a paper substrate which is suitable for binding silicone in a catalytic hydrosilation reaction, the method comprising steps of dissolving polyvinyl alcohol which has a weight average molecular weight of less than 50000 g/mol and degree of hydrolysis in the range of 70% to 99% into water, thereby obtaining a water-based solution containing dissolved polyvinyl alcohol, adding reactant which is an organic molecule that contains a catenated carbon structure having at least 4 carbon atoms, an aldehyde group and a functional vinyl group into the water-based solution containing the dissolved polyvinyl alcohol, thereby obtaining a reaction mixture reacting the reactant with the dissolved polyvinyl alcohol in a water-based acetalization reaction, thereby forming acetalized polyvinyl alcohol which contains functional vinyl groups, wherein the functional vinyl groups are part of catenated carbon structures which contain at least 4 carbon atoms, and which have an acetal connectivity with the backbone chain of the acetalized polyvinyl alcohol, and coating a cellulose fiber-based support layer with the acetalized polyvinyl alcohol, thereby forming a hydrophobic primer layer and the paper substrate, wherein the vinyl group molality of the acetalized polyvinyl alcohol is equal to or higher than 0.2 millimoles per gram of the acetalized polyvinyl alcohol. ### Claim 3 (depends on 2) The method according to claim 2, wherein the viscosity of the reaction mixture containing the acetalized polyvinyl alcohol is less than 8000 mPa s after the water-based acetalization reaction. ### Claim 4 (depends on 2) The method according to claim 2, further comprising removing unreacted reactant from the reaction mixture containing acetalized polyvinyl alcohol. ### Claim 5 (depends on 2) The method according to claim 2, wherein the dry matter content of the polyvinyl alcohol in the water-based solution is equal to or higher than 25 wt.-%. ### Claim 6 (depends on 2) The method according to claim 2, wherein the polyvinyl alcohol is partially hydrolyzed, such that the degree of hydrolysis of the polyvinyl alcohol is less than 97%, such as between 70% to 97%. ### Claim 7 (depends on 2) The method according to claim 2, wherein the polyvinyl alcohol is fully hydrolyzed, such that the degree of hydrolysis of the polyvinyl alcohol is equal to or more than 97%, such as between 97% to 99%. ### Claim 8 (depends on 2) The method according to claim 2, wherein the organic molecule is 10-undecenal or 2,2′-dimethyl-4-pentenal. ### Claim 9 (depends on 2) The method according to claim 2, wherein the acetalized polyvinyl alcohol has a weight average molecular weight of less than 50000 g/mol. ### Claim 10 (depends on 2) The method for manufacturing a paper substrate according to claim 2, wherein the catenated carbon structure is a linear hydrocarbon that terminates into a functional vinyl group at the other end of the chain, such as 10-undecylenic group. ### Claim 11 (depends on 2) The method for manufacturing a paper substrate according to claim 2, wherein the catenated carbon structures contain at least 5 carbon atoms, preferably in the range of 5 to 15 carbon atoms. ### Claim 12 (depends on 2) The method for manufacturing a paper substrate according to claim 2, wherein the vinyl group molality of the acetalized polyvinyl alcohol equal to or higher than 0.23 millimoles per gram, preferably equal to or higher than 0.3 millimoles per gram, most preferably equal to or higher than 0.5 millimoles per gram of the acetalized polyvinyl alcohol. ### Claim 13 (depends on 2) The method for manufacturing a paper substrate according to claim 2, wherein the vinyl group molality of the acetalized polyvinyl alcohol is in the range of 0.20 to 1.41, preferably in the range of 0.23 to 1.21, most preferably in the range of 0.28 to 1.01 millimoles per gram of the acetalized polyvinyl alcohol. ### Claim 14 (depends on 2) The method for manufacturing a paper substrate according to claim 2, wherein the cellulose fiber-based support layer is made of bleached chemical pulp. ### Claim 15 (depends on 1) A release liner which comprises a paper substrate according to claim 1 and a release layer based on a silicone compound that has been applied on the paper substrate. ### Claim 16 (canceled) ### Claim 17 (depends on 1) The paper substrate according to claim 1, wherein the catenated carbon structure is a linear hydrocarbon that terminates into a functional vinyl group at the other end of the chain, such as 10-undecylenic group. ### Claim 18 (depends on 1) The paper substrate according to claim 1, wherein the catenated carbon structures contain at least 5 carbon atoms, preferably in the range of 5 to 15 carbon atoms. ### Claim 19 (depends on 1) The paper substrate according to claim 1, wherein the vinyl group molality of the acetalized polyvinyl alcohol is equal to or higher than 0.23 millimoles per gram, preferably equal to or higher than 0.3 millimoles per gram, most preferably equal to or higher than 0.5 millimoles per gram of the acetalized polyvinyl alcohol. ### Claim 20 (depends on 1) The paper substrate according to claim 1, wherein the vinyl group molality of the acetalized polyvinyl alcohol is in the range of 0.20 to 1.41, preferably in the range of 0.23 to 1.21, most preferably in the range of 0.28 to 1.01 millimoles per gram of the acetalized polyvinyl alcohol. ### Claim 21 (depends on 1) The paper substrate according to claim 1, wherein the cellulose fiber-based support layer is made of bleached chemical pulp.