# US 2021/0274831 A1 · Lightweight Separating Base Paper > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0274831 A1 - Document ID: US20210274831A1 - Status: Published application - Kind: A1 - Application number: 17/257,807 - Filed: 2019-05-14 - Published: 2021-09-09 - Earliest claimed: 2018-07-27 - Assignees: delfortgroup AG - Applicants: Delfortgroup AG - Inventors: Tuomas Turtola - Web page: https://patentgrep.com/patent/US20210274831A1 ## CPC - A24D 1/02: with special covers - D21H 27/001: {Release paper} - A24D 1/20: Cigarettes specially adapted for simulated smoking devices - D21H 11/02: Chemical or chemomechanical {or chemothermomechanical} pulp - D21H 19/12: applied as a solution using water as the only solvent, e.g. in the presence of acid or alkaline compounds - D21H 19/34: comprising cellulose or derivatives thereof - D21H 19/38: characterised by the pigments - D21H 19/40: siliceous, e.g. clays - D21H 19/52: Cellulose; Derivatives thereof - D21H 19/54: Starch - D21H 19/60: Polyalkenylalcohols; Polyalkenylethers; Polyalkenylesters - D21H 19/828: {two superposed coatings, the first applied being non-pigmented and the second applied being pigmented} - D21H 27/00: Special paper not otherwise provided for, e.g. made by multi-step processes - D21H 27/10: Packing paper (packaging materials of special type or form B65D65/38) - A24D: CIGARS; CIGARETTES; TOBACCO SMOKE FILTERS; MOUTHPIECES OF CIGARS OR CIGARETTES; MANUFACTURE OF TOBACCO SMOKE FILTERS OR MOUTHPIECES - 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 invention relates to a separating base paper, having a mass per unit area of at least 25 g/m2 and at most 40 g/m2 and a density of at least 0.90 g/cm3 and at most 1.15 g/cm3. The separating base paper comprises at least 50 wt % of long-fiber pulp and is coated on at least one side with at least two coatings. The first coating is located between a paper surface and the second coating. The second coating is a topmost coating and comprises a water-soluble film-forming polymer, nanofibrillated cellulose, microfibrillated cellulose or nanocrystalline cellulose. The Cobb-Unger (120 s) value of the surface having said first and second coatings is at least 0.01 g/m2 and at most 0.90 g/m2. ## Claims ### Claim 1 Smoking article comprising a smokable material, which is capable of generating an aerosol upon combustion or heating, wherein the smokable material is wrapped with a paper serving as a wrapping material, said paper having a basis weight of at least 25 g/m2 and at most 40 g/m2, and is coated with a density of a at least 0.90 g/cm3 and at most 1.15 g/cm3, wherein the release base paper comprises at least 50% by weight softwood pulp and is coated on at least one side with at least two coatings, wherein the first coating is located between the paper surface and the second coating, wherein the second coating is the topmost coating and comprises a water-soluble film-forming polymer, nano-fibrillated cellulose, micro-fibrillated cellulose or nano-crystalline cellulose, and wherein the Cobb Unger (120 s) value for the surface with said first and second coating is at least 0.01 g/m2 and at most 0.90 g/m2. ### Claim 2 (depends on 1) Smoking article according to claim 1, wherein the basis weight of the paper is at least 30 g/m2 and/or at most 38 g/m2. ### Claim 3 (depends on 1) Smoking article according to claim 1, wherein the density of the paper is at least 0.95 g/cm3 and at most 1.10 g/cm3. ### Claim 4 (depends on 1) Smoking article according to claim 1, wherein the paper comprises at least 70% by weight softwood pulp. ### Claim 5 (depends on 1) Smoking article according to claim 1, wherein the air permeance of the paper, measured in accordance with the Gurley method defined in ISO 5636-5:2013, is at least 4000 s. ### Claim 6 (canceled) ### Claim 7 (canceled) ### Claim 8 (depends on 1) Smoking article according to claim 1, wherein the paper contains at most 40% by weight hardwood pulp. ### Claim 9 (depends on 1) Smoking article according to claim 1, wherein the paper contains at most 15% by weight filler materials. ### Claim 10 (depends on 1) Smoking article according to claim 1, wherein the first coating comprises a coating material which is selected from the group consisting of water-soluble film-forming polymers; nano-fibrillated cellulose; micro-fibrillated cellulose; nano-crystalline cellulose and mixtures thereof; and the second coating comprises a water-soluble film-forming polymer, nano-fibrillated cellulose, micro-fibrillated cellulose or nano-crystalline cellulose. ### Claim 11 (depends on 1) Smoking article according to claim 1, in which the amount of the first coating is at least 0.1 g/m2 and at most 4.0 g/m2. ### Claim 12 (canceled) ### Claim 13 (depends on 1) Smoking article according to claim 1, in which the amount of the second coating is at least 0.5 g/m2 and at most 5.0 g/m2. ### Claim 14 (depends on 1) Smoking article according to claim 1, in which the second coating comprises pigment particles, wherein the pigment particle has a flaky shape, and wherein the pigment particle is selected from the group consisting of kaolin, talcum, magnesium silicates, aluminum silicates and mixtures thereof. ### Claim 15 (depends on 1) Smoking article according to claim 1, in which the film-forming polymer of the second coating is selected from the group consisting of polyvinyl alcohol, carboxy methyl cellulose, hydroxy methyl cellulose, starch, starch derivatives, latex and mixtures thereof. ### Claim 16 (canceled) ### Claim 17 (depends on 1) Smoking article according to claim 1, in which the Cobb Unger (120 s) value for the coated side of the paper is at least 0.01 g/m2 and at most 0.90 g/m2. ### Claim 18 (depends on 1) Smoking article according to claim 1, wherein the paper has a transparency in accordance with DIN 53147:1993-01 of at least 55% and at most 80%. ### Claim at position 19 19-24. (canceled) ### Claim 25 (depends on 1) Process for manufacturing a paper for wrapping the smokable material of a smoking article according to claim 1, with the following steps: preparing a pulp-containing suspension, which comprises softwood pulp, applying the pulp-containing suspension to a wire of a paper machine in order to form a base paper, calendering the base paper to adjust the density of the base paper, coating the base paper with a first coating, drying the first coating, applying a second coating, which is a topmost coating, either directly or indirectly with one or more further layers in between, to the first coating, wherein the second coating comprises a water-soluble film-forming polymer, nano-fibrillated cellulose, micro-fibrillated cellulose or nano-crystalline cellulose, and drying the second coating, wherein the proportion of softwood pulp in the pulp-containing suspension is selected such that the finished paper comprises at least 50% by weight softwood pulp, the amount of pulp-containing suspension that is applied to the wire of the paper machine is selected such that the finished paper has a basis weight of at least 25 g/m2 and at most 40 g/m2, and the step of calendering is carried out such that the finished paper has a density of at least 0.90 g/cm3 and at most 1.15 g/cm3, and wherein the first and the second coating are selected such that the Cobb Unger (120 s) value for the surface with said first and second coating on the finished release base paper is at least 0.01 g/m2 and at most 0.90 g/m2. ### Claim 26 (depends on 25) Process according to claim 25, wherein the amount of pulp-containing suspension that is applied to the wire of the paper machine is selected such that the finished paper has a basis weight of at least 30 g/m2 and/or at most 38 g/m2. ### Claim 27 (depends on 25) Process according to claim 25, wherein the step of calendering is carried out such that the density is at least 0.95 g/cm3 and at most 1.10 g/cm3. ### Claim 28 (depends on 25) Process according to claim 25, in which the base paper in the calendering process is compressed between a plurality of pairs of rolls, wherein each pair of rolls forms a nip through which the base paper is guided. ### Claim 29 (depends on 25) Process according to claim 25, wherein the proportion of softwood pulp in the pulp-containing suspension is selected such that the finished paper comprises at least 70% by weight softwood pulp. ### Claim 30 (depends on 25) Process according to claim 25, in which the finished paper has an air permeance, measured in accordance with the method defined ISO 5636-5:2013 according to Gurley, of at least 4000 s. ### Claim 31 (depends on 25) Process according to claim 25, in which the step of manufacturing the pulp-containing suspension contains a step in which the softwood pulp is refined to a degree of refining of at least 50° SR and at most 80° SR. ### Claim 32 (depends on 25) Process according to claim 25, in which the first coating comprises a coating material that is selected from the group consisting of water-soluble film-forming polymer; nano-fibrillated cellulose, micro-fibrillated cellulose; nano-crystalline cellulose and mixtures thereof; and the second coating comprises a water-soluble film-forming polymer, nano-fibrillated cellulose, micro-fibrillated cellulose or nano-crystalline cellulose. ### Claim 33 (depends on 32) Process according to claim 32, in which the first coating is applied by means of a first coating composition which comprises water and said coating material, wherein the amount of the dried first coating composition which remains after drying on the paper is at least 0.1 g/m2 and at most 4.0 g/m2. ### Claim 34 (canceled) ### Claim 35 (depends on 25) Process according to claim 25, wherein the second coating comprises a water-soluble, film-forming polymer, nano-fibrillated cellulose, micro-fibrillated cellulose or nano-crystalline cellulose and is applied in form of a second coating composition which comprises water and said film-forming polymer, the nano-fibrillated cellulose, micro-fibrillated cellulose or nano-crystalline cellulose. ### Claim 36 (depends on 25) Process according to claim 25, in which the second coating composition comprises pigment particles, wherein the pigment particles have a flaky shape, and wherein the pigment particles are selected from the group consisting of kaolin, talcum, magnesium silicates, aluminum silicates, calcium carbonate and mixtures thereof, wherein the pigment particles make up at least 1% by weight, and at most 30% by weight, with respect to the weight of the second coating composition. ### Claim 37 (depends on 25) Process according to claim 25, in which the film-forming polymer of the second composition is selected from the group consisting of polyvinyl alcohol, carboxy methyl cellulose, hydroxy methyl cellulose, starch, starch derivatives, latex and mixtures thereof. ### Claim at position 33 38-39. (canceled) ### Claim 40 (depends on 25) Process according to claim 25, in which the paper machine is a Fourdrinier paper machine and/or in which a calendering device is integrated into the paper machine, so that the calendering can be carried out during production of the base paper and/or in which the first and/or the second coating composition is applied in a size press, in a film press, by blade coating or a curtain coating process. ### Claim 41 (depends on 1) Smoking article according to claim 1, wherein the smokable material is heated but not burnt during intended use. ### Claim 42 (depends on 9) Smoking article according to claim 9, wherein the paper contains less than 2% by weight filler materials. ### Claim 43 Smoking article according to claim to, wherein said water-soluble film-forming polymers are formed by starch, starch derivatives, cellulose derivatives or latex. ### Claim 44 (depends on 1) Smoking article according to claim 1, in which the Cobb Unger (120 s) value for the coated side of the paper is at least 0.1 g/m2 and at most 0.70 g/m2. ### Claim 45 (depends on 32) Process according to claim 32, wherein said water-soluble film-forming polymers are formed by starch, starch derivatives, cellulose derivatives or latex. ### Claim 46 (depends on 35) The process according to claim 35, wherein the water-soluble film-forming polymer, the nano-fibrillated cellulose, micro-fibrillated cellulose or nano-crystalline cellulose makes up at least 5% by weight and at most 25% by weight with respect to the weight of the second coating composition, and/or wherein the amount of the dried second coating composition which remains after drying on the paper is at least 0.5 g/m2 and at most 5.0 g/m2.