# US 12,595,625 B2 · Heat sealable barrier paperboard > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,595,625 B2 - Document ID: US12595625B2 - Status: Granted - Kind: B2 - Application number: 18/053,894 - Filed: 2022-11-09 - Published: 2023-03-16 - Granted: 2026-04-07 - Earliest claimed: 2017-02-27 - Assignees: WestRock MWV, LLC - Applicants: WestRock MWV, LLC - Inventors: Jiebin Pang; Natasha G. Melton; Teresa Krug; Steven Parker - Web page: https://patentgrep.com/patent/US12595625B2 ## CPC - D21H 19/12: applied as a solution using water as the only solvent, e.g. in the presence of acid or alkaline compounds - D21H 19/385: {Oxides, hydroxides or carbonates} - D21H 19/40: siliceous, e.g. clays - D21H 19/58: Polymers or oligomers of diolefins, aromatic vinyl monomers or unsaturated acids or derivatives thereof - D21H 19/60: Polyalkenylalcohols; Polyalkenylethers; Polyalkenylesters - D21H 27/10: Packing paper (packaging materials of special type or form B65D65/38) - D21J 1/08: Impregnated or coated fibreboard - D21H 19/82: superposed {(D21H19/84 takes precedence)} - 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 - D21J: FIBREBOARD; MANUFACTURE OF ARTICLES FROM CELLULOSIC FIBROUS SUSPENSIONS OR FROM PAPIER-MACHE (manufacture of articles by dry processes B27N) ## Abstract An aqueous coated paperboard is disclosed which exhibits good barrier properties and anti-blocking behavior and is heat sealable. ## Claims ### Claim 1 A paperboard comprising: a paperboard substrate having a first side and an opposing second side, the substrate having a caliper from about 10 to about 24 points; a heat sealable barrier layer applied on the first side as an aqueous coating forming an outer surface for the first side, wherein the aqueous coating comprises: a pigment blend; and a binder having a glass transition temperature above 20° C., wherein a ratio of the binder to the pigment blend is at least 1 part binder per 1 part pigment blend, by weight; and a printable coating on the second side, wherein the paperboard has a blocking rating below 4, and wherein the paperboard is at least 90% repulpable. ### Claim 2 (depends on 1) The paperboard of claim 1 wherein the binder comprises styrene-acrylate. ### Claim 3 (depends on 1) The paperboard of claim 1 wherein the glass transition temperature is above 30° C. ### Claim 4 (depends on 1) The paperboard of claim 1 wherein the glass transition temperature is above 35° C. ### Claim 5 (depends on 1) The paperboard of claim 1 wherein the ratio of the binder to the pigment blend is at least 1.25:1 by weight. ### Claim 6 (depends on 1) The paperboard of claim 1 wherein the ratio of the binder to the pigment blend is at least 1.5:1 by weight. ### Claim 7 (depends on 1) The paperboard of claim 1 wherein a heat seal formed between the first side and the second side, when made with a sealing bar at 350° F. (177° C.) and 50 psi (345 kPa) for 1.5 seconds, provides adhesion to the extent of 80% or greater fiber tear. ### Claim 8 (depends on 1) The paperboard of claim 1 exhibiting no fiber tear after being held under 100 psi (689 kPa) pressure at 50° C. for 24 hours. ### Claim 9 (depends on 1) The paperboard of claim 1 wherein the aqueous coating has a dry weight from 6 to 15 lb/3000 ft2 (9.8-24.5 g/m2). ### Claim 10 (depends on 1) The paperboard of claim 1 wherein the aqueous coating has a dry weight from 8 to 12 lb/3000 ft2 (13.1-19.6 g/m2). ### Claim 11 (depends on 1) The paperboard of claim 1 wherein the aqueous coating is applied in two coats. ### Claim 12 (depends on 1) The paperboard of claim 1 wherein the substrate comprises at least one of solid bleached sulfate and natural kraft board. ### Claim 13 (depends on 1) The paperboard of claim 1 providing a 2-minute water Cobb test of less than 5 g/m2. ### Claim 14 (depends on 1) The paperboard of claim 1 providing a 30-minute water Cobb test of less than 60 g/m2. ### Claim 15 (depends on 1) The paperboard of claim 1 providing a 30-minute oil Cobb test of less than 1 g/m2. ### Claim 16 (depends on 1) The paperboard of claim 1 providing a water vapor transmission rate of less than 900 g/m2. ### Claim 17 (depends on 1) The paperboard of claim 1 having a 3M Kit test rating of at least 7. ### Claim 18 (depends on 1) The paperboard of claim 1 being at least 95% repulpable. ### Claim 19 (depends on 1) The paperboard of claim 1 wherein the pigment blend comprises clay and calcium carbonate, and wherein a ratio of the clay to the calcium carbonate is about 1:1. ### Claim 20 (depends on 1) The paperboard of claim 1 wherein the heat sealable barrier layer is adhered to another surface with which it contacts.