Aqueous barrier coating for moldable cellulosic substrates and cellulosic substrate coated with aqueous barrier coating

Abstract

Aqueous barrier coating for mold-formable cellulosic substrates and cellulosic substrate coated with the aqueous barrier coating. An aqueous barrier coating for moldable cellulosic substrates comprises a mixture of A) at least one aqueous dispersion of polymer binder at 40% by weight to 95% by weight, B) at least one active filler at 3% by weight to 30% by weight, and C) one or more optional additives, such as wetting agents, dispersants, thickeners, defoamers and crosslinking agents. Crystallinity is present in at least one of the polymer binder dispersion and active filler particles. The resulting dry film has a shear storage modulus between 50 °C and 60 °C in the range of 1.5×10⁶ to 1×10⁹ Pascal, a shear storage modulus between 80 °C and 90 °C in the range of 2×10⁵ to 5×10⁷ Pascal, and a shear storage modulus between 100 °C and 110 °C in the range of 5×10³ to 1×10⁶ Pascal.The percentage by total weight of crystalline polymer binder and crystalline active filler combined is greater than 50%.

Description

1 / 28 Aqueous barrier coating for mold-formable cellulosic substrates, and cellulosic substrate coated with the aqueous barrier coating. FIELD OF THE INVENTION

[001] The present invention relates to an environmentally friendly, recyclable, repulpable, heat-sealable and overprintable aqueous barrier coating, with a barrier to water, oil, grease and / or moisture that can be used on a cellulosic substrate to form molded products, such as paper cups and food serving trays. FUNDAMENTALS OF THE INVENTION

[002] Cellulose-based packaging materials for product containers and packaging, such as packaging paper or cardboard, are generally provided with a polymer coating that makes the materials liquid-proof and allows the container or packaging to be formed by heat sealing. Food and foodservice packaging using paper or cardboard generally requires enhanced barrier properties, including barriers against oil, grease, water, and / or moisture vapor. In addition, many paper or cardboard packages, for example, paper or cardboard stock for food or beverage services, also require the paper or cardboard to be heat-sealable, making it possible to form cups in a cupping machine.

[003] Low-density polyethylene (LDPE) is widely used for coating due to its good liquid barrier properties (i.e., resistance to water, tea, coffee, etc.) and good heat sealing. The crystallinity in the LDPE film helps the polymer melt readily when the melting point is reached to provide the seal, and its rapid recrystallization during the cooling step allows for quick seal protection when pressure is removed. Currently, extruded polyethylene (PE) coated cardboard still dominates in such applications, providing the necessary barrier and heat sealing properties. However, Petition 870240025152, dated 03 / 22 / 2024, page 10 / 15 2 / 28 Packaging, including paper cups and trays using a PE extrusion coating, has difficulties in repulping and is not as easily recyclable as conventional paper or cardboard, creating problems in recovering useful fibers from the packaging and causing environmental concerns if this packaging ends up in landfills. There is increasing demand for alternative solutions, including coating technologies to replace cardboard packaging that contain a PE coating or film layer.

[004] Water-based repulpable and recyclable coatings are one of the promising solutions to meet this need. However, most water-based coatings still cannot meet the requirements compared to LDPE extrusion-coated paper / cardboard for several reasons, including good sealing strength, fast sealing speed, good roll block strength, providing an adequate barrier to water, oil, grease and / or moisture, as well as offering overprintability with decorative inks. Balancing all these necessary properties is difficult, as they can be contradictory to each other.For example, most polymers or binders in water-based coatings are amorphous and become soft and sticky at elevated temperatures (even 50-55 °C) and / or pressure during the production, conversion, shipping, and storage of the coated board, causing blockage, while it has to maintain the same cure-seal conversion rate as LDPE-coated boards, especially in a cup manufacturing process. Another example is achieving acceptable barrier properties at very low dry coating weight, 5 to 15 grams per square meter (g / m2), compared to extruded LDPE at 25 to 50 g / m2 coating weight. Another balancing act is between good barrier properties (usually achieved by lower surface tension) and ink overprintability, especially with water-based inks. Petition 870220102292, dated 04 / 11 / 2022, page 15 / 52 3 / 28

[005] Much of the state of the art exists in relation to cellulosic treatment with coatings, including, for example, Moncla et al., EP 1963573B1 and Aho et al., EP 0991815B1. Moncla discloses a paper on cellulose incorporating cellulose fibers with an aqueous dispersion. Aho discloses a coating with at least one polymer dispersion, a talc-containing polymer dispersion applied to the inner surface of the container, applied only during the manufacturing process on a plate machine. BRIEF SUMMARY OF THE INVENTION

[006] The present invention provides an aqueous barrier coating that is environmentally friendly, recyclable, heat-sealable and overprintable, having resistance to the permeation of water, oil, grease and other hot and cold liquids and that can be used on cellulosic substrates for formed constructions, including paper cups and food serving trays.The aqueous barrier coating comprises a mixture of A) at least one aqueous dispersion of polymer binder, at 40% by weight to 95% by weight, B) at least one active filler at 3% by weight to 30% by weight, C) one or more optional additives (including, but not limited to, wetting, dispersing, thickening, antifoaming and crosslinking agents); wherein crystallinity is present in at least one of the at least one polymer binder dispersion (composition A) or the at least one active filler (composition B); and that the resulting dry film has a shear storage modulus between 50 °C and 60 °C in the range of 1.5*10⁶ to 1*10⁹ Pascal, a shear storage modulus between 80 °C and 90 °C in the range of 2*10⁵ to 5*10⁷ Pascal, and a shear storage modulus between 100 °C and 110 °C in the range of 5*10³ to 1*10⁶ Pascal.The total weight percentage of crystalline polymer binder and crystalline active filler combined is greater than 50%, preferably greater than 60%, and most preferably greater than 65%. The aqueous barrier coating can be applied to one or both main sides of the cellulosic substrate. Optionally, a primer of... Petition 870220102292, dated 04 / 11 / 2022, p. 16 / 52 4 / 28 Aqueous sealant may be applied and dried on one or both main sides of the cellulosic substrate prior to the application of the barrier coating, wherein the aqueous sealant primer comprises A) at least a 30-90% aqueous dispersion of polymer binder, B) at least one regular filler chosen from coating grade clays, calcium carbonate, talc, barium sulfate, zinc sulfate, aluminum sulfate, reaction products of calcium oxide, titanium dioxide, lithopone, zinc sulfide, alumina, silica, sodium hexametaphosphate and mineral particles pre-treated with polymer binder at 5-60% by weight and C) one or more optional additives, such as wetting agents, dispersants, thickeners, wax defoamers and crosslinking agents).

[007] A cellulosic substrate coated with the aforementioned inventive aqueous barrier coating with or without the optional sealing primer provides easy repulping and recycling capability, good heat sealing capability, resistance to roll blockage, container forming characteristic, good barrier to water (including hot water and hot coffee), oils and greasy liquids, as well as exhibiting good overprinting capability. BRIEF DESCRIPTION OF THE DRAWINGS

[008] FIG. 1 illustrates a cellulosic substrate coated on its first main side with the inventive aqueous barrier coating.

[009] FIG. 2 illustrates a cellulosic substrate coated on its first main side with an aqueous sealing primer and the aqueous barrier coating.

[010] FIG. 3 illustrates a cellulosic substrate coated on both its first and second principal sides with the aqueous barrier coating.

[011] FIG. 4 illustrates a cellulosic substrate with both main sides coated with an aqueous sealing primer, followed by the aqueous barrier coating. Petition 870220102292, dated 04 / 11 / 2022, p. 17 / 52 5 / 28

[012] FIGS. 5A and 5B illustrate the main thickness difference between an extruded LDPE coating on a pair of cellulosic substrates sealed together (FIG. 5A) and the aqueous barrier coating of the invention (FIG. 5B), alone or with an aqueous sealing primer on a similar pair of cellulosic substrates.

[013] FIG. 6 illustrates the shear modulus of elasticity of a typical LDPE as applied to extruded LDPE cellulosic substrates in a heating range with specified shear modulus of elasticity ranges of a dry film aqueous barrier coating in various temperature ranges.

[014] FIG. 7 illustrates the various shear modulus curves for examples of the present invention and comparative examples of other coatings. DETAILED DESCRIPTION OF THE INVENTION

[015] The present invention provides an aqueous barrier coating that is environmentally friendly, recyclable, heat-sealable, roll block resistant, and overprintable. The aqueous coating is resistant to the permeation of water, oil, grease, and other hot and cold liquids and can be used on cellulosic substrates to form molds, including paper cups and food serving trays. The aqueous barrier coating of the present invention comprises a mixture of A) at least one aqueous dispersion of polymer binder at 40% by weight to 95% by weight, B) at least one active filler at 3% by weight to 30% by weight, and C) one or more optional additives, including, but not limited to, wetting, dispersing, thickening, and antifoaming agents. Crystallinity is present in at least one of the at least one polymer binder dispersion (composition A) or the at least one active filler (composition B).The resulting dry film has a shear storage modulus between 50 °C and 60 °C in the range of 1.5x10⁶ to 1x10⁹ Pascal, and a shear storage modulus between 80 °C. Petition 870220102292, dated 04 / 11 / 2022, page 18 / 52 6 / 28 and 90 °C in the range of 2*10⁵ to 5*10⁷ Pascal and a shear storage modulus between 100 °C and 110 °C is in the range of 5*10³ to 1*10⁶ Pascal. The total weight percentage of the combined crystalline polymer binder and crystalline active filler is greater than 50%, preferably greater than 60%, and most preferably greater than 65%.

[016] The aqueous barrier coating may be applied to one or both main sides of the cellulosic substrate. Optionally, an aqueous sealing primer may be applied and dried on one or both main sides of the cellulosic substrate prior to application of the barrier coating. The aqueous sealing primer comprises A) at least one aqueous dispersion of polymer binder at 30-90% by weight, B) at least one regular filler chosen from coating grade clays, calcium carbonate, talc, barium sulfate, zinc sulfate, aluminum sulfate, reaction products of calcium oxide, titanium dioxide, lithopone, zinc sulfide, alumina, silica, sodium hexametaphosphate and mineral particles pre-treated with polymer binder at 5-60% by weight and C) one or more optional additives, such as wetting agents, dispersants, thickeners, wax defoamers and crosslinking agents.

[017] The cellulosic substrate in this document may comprise cellulosic materials. Such cellulose-based substrates may include paper. The term “paper,” as used in this document, shall be understood to mean all forms of paper, including board, such as cardboard products, white-coated board, lining board, and poster board. Paper may also include newsprint, uncoated groundwood, coated groundwood, coated freesheet, uncoated freesheet, wrapping papers, industrial papers, corrugated media, writing paper, letter paper, photographic quality paper, or wallpaper. Cellulose-based substrates may be formed from one or more webs, for example, a single-layer or multi-layer paper web formed from a blend of fibers. As seen in the Figures, the substrate Petition 870220102292, dated 04 / 11 / 2022, page 19 / 52 7 / 28 cellulosic 100 can be (or may include) any cellulosic material that is capable of being coated with the optional aqueous sealing primer 120 and the aqueous barrier coating layer 110 on one side 101 or both sides (101 and 102) of this cellulosic substrate. Those skilled in the art will appreciate that the cellulosic substrate 100 can be bleached or unbleached. Examples of suitable cellulosic cardboard substrates include corrugated board, lining board, bleached solid sulfate (SBS), unbleached uncoated kraft (UUK), and folding box board (FBB). FIG. Figure 5 illustrates the main difference in thickness between an extruded LDPE coating on a pair of cellulosic substrates sealed together and the aqueous barrier coating of the invention, alone or with an aqueous sealing primer on a similar pair of cellulosic substrates.The difference in thickness demonstrates the difference in potential thermal conductivity of sealed containers (such as cups) made from two processes, since these polymers themselves are poor conductors and the weight of the thinner coating would be more affected by the temperature of the liquids it contains.

[018] The 100 cardboard substrate may have an uncoated base weight of at least about 40 pounds per 3,000 ft². In one embodiment, the 100 cardboard substrate may have an uncoated base weight ranging from about 40 pounds per 3,000 ft² to about 300 pounds per 3,000 ft². In another embodiment, the 100 cardboard substrate may have an uncoated base weight ranging from about 85 pounds per 3,000 ft² to about 250 pounds per 3,000 ft². In one embodiment, the 100 cardboard substrate may have an uncoated base weight ranging from about 100 pounds per 3,000 ft² to about 220 pounds per 3,000 ft². In addition, the 100-ply cardboard substrate can have a gauge (thickness) ranging from about 4 points to about 30 points (0.008 inch to 0.030 inch). In one embodiment, the gauge range is from about 8 points to about 24 points. Petition 870220102292, dated 04 / 11 / 2022, p. 20 / 52 8 / 28 points. In another category, the caliber range is approximately 14 points to approximately 18 points.

[019] Despite numerous attempts, as described above in the prior art, to develop an aqueous barrier coating for cellulosic substrates in an effort to replace the LDPE extruded board that currently dominates the market, none have successfully demonstrated offering the balanced properties of LDPE extruded boards, including water (cold and hot) and oil and grease barrier resistance, good heat sealing and roll blockage resistance, as well as demonstrating acceptable container formation, process behavior and overprinting capability, combined with easy repulping and recycling capability. There are three important aspects that are overlooked by many but are critical to the successful replacement of LDPE extruded boards. The first aspect is the difference in coating thickness between the LDPE extrusion option as shown in FIG.Figure 5A and an alternative aqueous barrier coating, as shown in FIG. 5B. A lower dry coating thickness for the aqueous coating alternative (12-15 microns vs. 25-50 microns) means that the aqueous barrier coating will have a greater demand as a barrier to water, oil, and grease that must be accommodated. For hot liquid applications, such as for hot water and hot cups of coffee, the heat from the hot liquid will be more easily conducted through the sealing lines and may soften the thinner dry aqueous barrier coatings that join two layers; and that in the hot sealing process, the thinner dry aqueous layer will heat up much more quickly and will change the processing variables.

[020] The second aspect is crystallinity in LDPE extrusion polymers. Crystallinity allows the LDPE polymer to melt and flow more rapidly above its melting point, while also aiding in the rapid development of the thermal seal bond when cooled. Petition 870220102292, dated 04 / 11 / 2022, page 21 / 52 9 / 28 up to a temperature slightly below its melting point due to the phenomenon known as heating-cooling hysteresis. The melting point of LDPE in the range of 95 °C to 110 °C makes it non-blocking during processing, storage and shipping without the addition of any other antiblocking additive.

[021] The third aspect is the elastic modulus profile of LDPE in the use / service temperature range from ambient temperature to the storage and shipping temperature range and even up to the heat-sealing temperature range during the cup manufacturing process. Although the melting point of the crystallinity of the individual component or the entire composition of aqueous barrier coatings, as well as the glass transition of the polymer film, can be measured or determined, the melting point, Tg, or its transition range cannot be used to determine whether the resulting film can be processed similarly to LDPE, whether it is strong enough, or whether it can produce a bond strength similar to that of LDPE material.The modulus of elasticity can define the strength of a polymer in its solid, transition, and molten states and can be used to characterize and define the processivity of the dry film of aqueous barrier coatings compared to those of LDPE. It appears that no prior art has recognized the ability to use the modulus of elasticity as a measure of the effectiveness of an aqueous barrier coating as a substitute for LDPE. In particular, it has been determined that the shear modulus profile from a rheometric dynamic analyzer (RDA) can be used to develop a polymer film suitable for use across a temperature range, for example, from 0 °C to 130 °C, without losing material integrity during the measurement itself. The shear modulus of elasticity of LDPE used in the manufacture of extruded LDPE cardboard is shown in FIG. 6.Without being limited to any particular theory, we chose a shear modulus of elasticity in the temperature ranges of 50 °C to 60 °C, 80 °C to 90 °C, and 100 °C to 110 °C. Petition 870220102292, dated 04 / 11 / 2022, page 22 / 52 10 / 28 for the dry aqueous barrier coating to describe its blockage-resistant zone, transition zone, and fusion zone, as well as the flow velocity. It is the crystallinity in one or more of components A and B of the present invention, as well as the shear modulus of elasticity in the three temperature zones, that allows the composition to be a viable alternative to LDPE. The resulting dry film has a shear storage modulus between 50 °C and 60 °C in the range of 1.5x10⁶ to 1x10⁹ Pascal, a shear storage modulus between 80 °C and 90 °C in the range of 2x10⁵ to 5x10⁷ Pascal, and a shear storage modulus between 100 °C and 110 °C in the range of 5x10³ to 1x10⁶ Pascal.

[022] In the aqueous barrier coating of this invention, the crystallinity may come from at least one of the aqueous binder dispersions in composition A and / or from at least one of the active fillers in composition B, wherein the active filler is dry wax particle or pre-dispersed wax particle dispersion as provided and has a defined melting point. Without being limited to any particular theory, the crystallinity in the aqueous polymer binder dispersion or in the melt wax helps to determine the anti-block temperature, the tensile strength below and above the melting point of the composition and the melt flow rate as well as the rate of bond development during the hot sealing cycles of the coated cellulosic substrate.

[023] The melting point associated with crystalline materials can be better characterized and measured by differential scanning calorimetry (DSC) according to ASTM D3418. The melting point of the crystalline phase of at least one of the aqueous binder dispersions in composition A of the aqueous barrier coating is in the range of 50 °C to 140 °C, preferably in the range of 60 °C to 130 °C, and more preferably in the range of 65 °C to 120 °C. The crystalline polymer in the aqueous binder dispersion are dispersions of a homopolymer. Petition 870220102292, dated 04 / 11 / 2022, page 23 / 52 11 / 28 containing ethylene, water-stabilized copolymers and mixtures thereof, including those mentioned in US 2007 / 0292705 and EP 1963573B1; aqueous dispersion of ethylene-acrylic acid (EAA) and ethylene-methacrylic acid copolymers, such as those available under the trademarks PRIMACOR™ (trademark of SK Global Chemical), NUCREL™ (trademark of E. L. DuPont de Nemours) and ESCOR™ (trademark of ExxonMobil) and described in US Pat. Nos. 4,599,392, 4,988,781 and 5,938,437, as well as CN105102508A. The aqueous dispersion of polymers includes ethylene ethyl acrylate (EEA), ethylene methyl methacrylate (EMMA) and ethylene butyl acrylate (EBA) copolymers; Other aqueous dispersions of ethylene-carboxylic acid copolymers may also be used, including ethylene / methacrylic acid copolymers, ethylene / itaconic acid copolymers, ethylene / methyl hydrogen maleate copolymers, ethylene / maleic acid copolymers,ethylene / acrylic acid / methyl methacrylate terpolymers, ethylene / acrylic acid / ethyl acrylate terpolymers, ethylene / methacrylic acid / ethyl acrylate terpolymers, ethylene / itaconic acid / methyl methacrylate terpolymers, ethylene / methyl hydrogen terpolymers, maleate / ethyl acrylate terpolymers, ethylene / acrylic acid / vinyl acetate terpolymers, ethylene / methacrylic acid / vinyl acetate terpolymers, ethylene / acrylic acid / vinyl alcohol terpolymers, ethylene / propylene / acrylic acid terpolymers, ethylene / acrylamide / acrylic acid terpolymers, ethylene / styrene / acrylic acid terpolymers, ethylene / methacrylic acid / acrylonitrile terpolymers, ethylene / fumaric acid / vinyl methyl ether terpolymers, ethylene / vinyl chloride / acrylic acid terpolymers ethylene / vinylidene chloride / acrylic acid, polyethylene / acrylic acid graft copolymers, polyethylene / methacrylic acid graft copolymers,Polymerized ethylene / propylene / acrylic acid graft terpolymers; fatty acid-modified polyester terephthalate (PET) and liquid resin-modified soft polyester terephthalate (PET) as described in CA 2818315A1. Those, Petition 870220102292, dated 04 / 11 / 2022, page 24 / 52 Those skilled in the art will recognize that a number of other polymers can also be used.

[024] Suitable aqueous non-crystalline polymer binder dispersions in composition A of aqueous barrier coatings include, but are not limited to, acrylic-based polymers or copolymers, acrylic vinyl acid copolymers, styrene acrylic copolymers, styrene-butadiene copolymers, styrene-acrylate copolymers, styrene-acrylonitrile copolymers, styrene-acrylonitrile acrylate copolymers, polyurethanes, polyvinyl alcohols, polyvinyl acetates, dextrin, modified starches, asphalt emulsions, corn starch, nylon, polypropylene, polyhydroxyalkanoates, combinations thereof and the like. Some suitable examples of commercial acrylic-based polymer dispersion products for food contact applications include Joncryl® DFC 3030, available from BASF, NeoCryl A-2092, available from DSM, and Texicryl 13-525, available from Scott Bader.Texicryl 13-814, available from Scott Bader, Neocryl A-1095, available from DSM, and Induprint SE 245, available from Indulor, can be used in non-food applications. Some suitable examples of commercially available styrene-butadiene copolymer dispersion products suitable for inclusion in the coating compositions described in this document for food contact applications include Genflo 3003, available from Omnova Solutions, Rovene 4019, available from Mallard Creek, and Savinex 98F10, available from Synthetic Latex Company. For non-food contact applications, products include, for example, Rovene 4009, available from Mallard Creek, and ENCOR DL 313 4009, available from Arkema.

[025] The “active” fillers of composition B of the aqueous barrier coating can not only reduce the cost of the coating, but, more importantly, provide a specific contribution to the barrier properties, raise the shear modulus curve and provide block strength. These active fillers include waxes Petition 870220102292, dated 04 / 11 / 2022, page 25 / 52 13 / 28 crystalline and non-crystalline standard fillers that contribute to the barrier properties.

[026] The crystalline waxes in the active filler of composition B of the aqueous barrier coating can be a dry wax particle or a dispersion of pre-dispersed wax particles with a melting point in the range of 70 °C to 145 °C, preferably in the range of 80 °C to 130 °C and more preferably in the range of 95 °C to 125 °C. Suitable melting waxes include, but are not limited to, paraffin waxes, acrylic-grafted paraffin waxes, crystalline waxes, polyethylene waxes (high density and low density), synthetic hydrocarbon waxes produced by the Fisher-Tropsch process, polypropylene waxes, oxidized polyethylene waxes, polyethylene / amide waxes, polyethylene / carnauba waxes, polyethylene / polytetrafluoroethylene waxes, carnauba waxes, ethylene-bisstearamide (EBS) waxes, ethylene-bis-oleamide waxes, and combinations thereof and the like.

[027] Suitable non-crystalline active fillers in composition B of the aqueous barrier coating include, but are not limited to, coating grade clays, calcium carbonate, talc, barium sulfate, zinc sulfate, aluminum sulfate, calcium oxide reaction products, titanium dioxide, lithopone, zinc sulfide, alumina, silica, sodium hexametaphosphate and polymer binder pre-treated mineral particles, as identified in U.S. Pat. No. 9,803,088B2, U.S. 2011 / 0046284A1, EP2470718A2, EP2470718B1, U.S. 2013 / 0225744A1 and mixtures thereof.

[028] Optional additives that may be used in aqueous barrier coatings and optional sealing primer include antifoaming agents, wetting agents, leveling agents, colloidal stabilizers, rheology modifiers, biocides, pesticides, surfactants, adhesion promoters, silicones, light stabilizers, degassing additives, ammonia, flow promoters, antioxidants, stabilizers, dispersants, plasticizers, rheological additives, crosslinking agents and others as known in Petition 870220102292, dated 04 / 11 / 2022, page 26 / 52 14 / 28 technique, as well as combinations thereof. In addition, other additives may be added to the coatings of the present invention in order to increase the usefulness of the coatings or of the coatings produced by curing the coatings. For example, plasticizers, antimicrobials, coloring agents, optical brighteners, ultraviolet absorbers, antioxidants and the like may be incorporated into the coatings of the present invention, if desired.

[029] The aqueous polymer binder in composition A for use in aqueous sealing primer includes, but is not limited to, acrylic-based polymers or copolymers, acrylic vinyl acid copolymers, styrene acrylic copolymers, styrene-butadiene copolymers, styrene-acrylate copolymers, styrene-acrylonitrile copolymers, styrene-acrylonitrile-acrylate copolymers, polyurethanes, polyvinyl alcohols, polyvinyl acetates, dextrins, modified starches, asphalt emulsions, corn starch, nylon, polypropylene, polyhydroxyalkanoates, as well as ethylene-containing homopolymer dispersions, water-stabilized copolymers, including those mentioned in US 2007 / 0292705 and EP 1963573B1; Aqueous dispersions of ethylene-acrylic acid (EAA) and ethylene-methacrylic acid copolymers, such as those available under the trademarks PRIMACOR™ (registered trademark of SK Global Chemical), NUCLRE™ (registered trademark of E.(DuPont de Nemours™) and (registered trademark of ExxonMobil) and described in U.S. Pat. Nos. 4,599,392, 4,988,781 and 5,938,437, as well as in CN105102508A: aqueous dispersion of polymers including ethylene ethyl acrylate (EEA), ethylene methyl methacrylate (EMMA) and ethylene butyl acrylate (EBA) copolymers; other aqueous dispersion of ethylene-carboxylic acid copolymer may also be used, including ethylene / methacrylic acid copolymers, ethylene / itaconic acid copolymers, ethylene / methyl hydrogen maleate copolymers, ethylene / maleic acid copolymers, ethylene / acrylic acid / methyl methacrylate terpolymers, ethylene / acrylic acid / ethyl acrylate terpolymers, terpolymers of. Petition 870220102292, dated 04 / 11 / 2022, page 27 / 52 15 / 28 ethylene / methacrylic acid / ethyl acrylate terpolymers, ethylene / itaconic acid / methyl methacrylate terpolymers, ethylene / methyl hydrogen terpolymers, maleate / ethyl acrylate terpolymers, ethylene / acrylic acid / vinyl acetate terpolymers, ethylene / methacrylic acid / vinyl acetate terpolymers, ethylene / acrylic acid / vinyl alcohol terpolymers, ethylene / propylene / acrylic acid terpolymers, ethylene / acrylamide / acrylic acid terpolymers, ethylene / styrene / acrylic acid terpolymers, ethylene / methacrylic acid / acrylonitrile terpolymers, ethylene / fumaric acid / vinyl methyl ether terpolymers, ethylene / vinyl chloride / acrylic acid terpolymers, ethylene / vinylidene chloride / acrylic acid terpolymers, polyethylene / acrylic acid graft copolymers, graft copolymers of Polyethylene / methacrylic acid, polymerized ethylene / propylene / acrylic acid graft terpolymers;Fatty acid-modified polyester terephthalate (PET) and liquid resin-modified soft polyester terephthalate (PET) as described in CA 2818315A1 and combinations thereof and the like.

[030] Suitable non-crystalline active fillers in composition B of the aqueous barrier coating include, but are not limited to, coating grade clays, calcium carbonate, talc, barium sulfate, zinc sulfate, aluminum sulfate, calcium oxide reaction products, titanium dioxide, lithopone, zinc sulfide, alumina, silica, sodium hexametaphosphate and polymer binder pre-treated mineral particles, as identified in U.S. Pat. No. 9,803,088B2, U.S. 2011 / 0046284A1, EP2470718A2, EP2470718B1, U.S. 2013 / 0225744A1 and mixtures thereof.

[031] The appropriate dry coating weight for aqueous barrier coating is in the range of 3 g / m2 to 30 g / m2, preferably in the range of 5 g / m2 to 25 g / m2, and more preferably in the range of 8 g / m2 to 20 g / m2. If an optional aqueous sealing primer is used under the aqueous barrier, the dry coating weight of the aqueous barrier coating can be expected to be lower and in the range of 3 g / m2 to 25 g / m2. Petition 870220102292, dated 04 / 11 / 2022, p. 28 / 52 16 / 28 preferably in the range of 4 g / m2 to 20 g / m2, and more preferably in the range of 5 g / m2 to 15 g / m2 to achieve acceptable barrier performance against water (hot or cold), oil and grease. Typical properties of aqueous barrier coatings are: viscosity in the range of 100 centipoise (cps) to 500 cps, preferably in the range of 150 cps to 500 cps, and more preferably in the range of 190 cps to 350 cps; % solids in the range of 25% to 50%, preferably in the range of 30% to 45%, and more preferably in the range of 35% to 40%, and pH value in the range of 7 to 11, more preferably in the range of 8 to 10, and more preferably in the range of 8.5 to 9.5.

[032] A suitable dry coating weight for aqueous sealing primer is in the range of 3 g / m2 to 20 g / m2, preferably in the range of 5 g / m2 to 15 g / m2, and more preferably in the range of 7 g / m2 to 12 g / m2. Typical properties of aqueous barrier coatings are: viscosity in the range of 150 centipoise (cps) to 5000 cps, preferably in the range of 200 cps to 3000 cps, and more preferably in the range of 300 cps to 1000 cps; % solids in the range of 30% to 60%, preferably in the range of 40% to 55%, and more preferably in the range of 45% to 50%; pH value in the range of 7 to 11, more preferably in the range of 8 to 10, and most preferably in the range of 8.5 to 9.5.

[033] The cellulosic substrate is substantially flat and the aqueous barrier coating and optional aqueous sealing primer can be applied using a rod coater, a helix coater, an air knife coater, a curtain coater, a slit die coater, an isobar rod coater, an etching coater, a reverse etching coater or by flexography. In another optional aspect, the aqueous barrier coating and optional aqueous sealing primer are applied using a rod coater where the rod is provided with a resilient tip measuring element. In another optional aspect, the rod provided with a resilient tip measuring element is Petition 870220102292, dated 04 / 11 / 2022, p. 29 / 52 17 / 28 an INVOR tip. In another optional aspect, a curtain coater is used to apply one or more of the following: aqueous barrier coating, optional aqueous sealing primer, and multi-layer topcoat.

[034] In another optional aspect, the aqueous barrier coating and the optional aqueous sealing primer are dried at a temperature of about 50 °C to about 125 °C, or preferably 60 °C to about 125 °C, or more preferably 70 °C to about 120 °C. Examples

[035] The following parameters apply to the examples presented in this document:

[036] Viscosity - Viscosity was measured using a Brookfield LV model viscometer with appropriate shaft and rpm at 25 °C or temperature determined by the manufacturer's instructions.

[037] Solids percentage: The EPA 24 method and theoretical calculations based on the solids content of each raw material are used to determine the solids percentage of the water-based coating composition.

[038] Heat Sealing: A Lab heat sealing unit from Packaging Industries, Inc., Model 12A9 was used to perform the sealing test. Two coated sheets were stacked together with the first leading side of both sheets facing down in the same direction. The stacked sheets are placed in the heat sealing zone of the heat seal with heating only from the top heated bar with the heat sealing conditions set to 24 psi for 1 second at 375 °F (interface temperature of 190-195 °C). The percentage of fiber tear along the heat seal strip is recorded as a measure of seal quality, with 100% fiber tear as the perfect seal, above 80% is preferable, and above 90% is more preferable. Petition 870220102292, dated 04 / 11 / 2022, p. 30 / 52 18 / 28

[039] Laboratory Drying Conditions: The laboratory-prepared aqueous barrier coating and the optional aqueous sealing primer coated sheets are dried at 90-100°C for 30 seconds before handling.

[040] Blocking Resistance: The blocking behavior of the samples was tested by evaluating the adhesion between the barrier-coated side and the uncoated side. The coated cardboard was cut into 2x2 square samples (5.1 cm*5.1 cm). Multiple duplicates were tested for each condition, with each duplicate evaluating the blocking between a pair of samples (e.g., if four duplicates were tested, four pairs – eight pieces – would be used). Each pair was positioned with the barrier-coated side of one piece in contact with the uncoated side of the other piece. The pairs were placed in a stack with a spacer (blade, release paper, or even copy paper) between adjacent pairs. The entire stack of samples was placed under a load of 100 psi, 50 °C for 24 hours. The test stack was then removed from the test environment and cooled to room temperature. The pressure was then released and the samples removed from the stack.The samples were evaluated for stickiness and blocking by separating each pair of cardboard sheets. Blocking damage is visible as fiber tearing, which, if present, generally occurs with fibers pulling away from the unbarriered surface of the samples. The results were reported as... 5: Excellent: crumbles easily, with no tendency to block. 4: Good: Slight adhesion, but separates without fiber separation or tearing. 3: OK: Slight stickiness or stickiness during separation, but no fiber collection. 2: Poor: Medium to strong adhesion or stickiness during separation and up to 25% coating damage or fiber separation. 1: Poor: More than 25% fiber tear. Petition 870220102292, dated 04 / 11 / 2022, page 31 / 52 19 / 28

[041] Cobb Test for Water Resistance: An indicator of the effectiveness of the liquid barrier properties of a coating composition is the amount of liquid that a coated substrate will absorb in a specified period of time. The TAPPI T 441 test method was employed to measure the water absorptivity of the coated substrate using a Cobb Sizing Tester (Testing Machines, Inc., Model 61-04). Water absorptivity (Cobb value) is defined as the mass of water absorbed in a specific time per 1 m² of paper, board, or corrugated fiberboard under 1 cm of water. The standard test time is a period of 30 min. A Cobb value of less than 10 g / m² and preferably less than 5 g / m² is generally required for liquid packaging.

[042] 3M Kit Test for Oil and Grease Resistance: The oil and grease resistance (OGR) of the samples was measured on the “barrier side” using the 3M kit test (TAPPI Standard T559 cm-02). With this test, ratings range from 1 (lowest oil and grease resistance) to 12 (excellent resistance to oil and grease penetration). A rating of 10 and above is a preferred requirement for liquid packaging.

[043] Stain Resistance Test (Oil and Grease Resistance): In addition to the 3M test kit, an oil absorbency test was performed to compare oil and grease resistance on various coated paper substrates. The coated sheet was cut into 4-inch x 4-inch (10 mm x 10 mm) squares and then scored along a diagonal line from corner to corner on the coated side (first primary side), then scored along another diagonal line at opposite corners on the second primary side. Using a mixture of corn oil dyed with an oil-soluble dye (1.0%), 1.0 ml of this solution was applied to a 3-inch x 3-inch (76 mm x 76 mm) blotting paper sheet, saturating the sheet. The blotting paper was then applied to the surface of the first primary coated side of the coated paper. On the other side of the coated barrier paper, a 4-inch x 4-inch (10 mm x 76 mm) stain absorbent sheet was applied. Petition 870220102292, dated 04 / 11 / 2022, p. 32 / 52 A 20 / 28 mm*10 mm (20 / 28 mm*10 mm) sheet was placed to absorb any oil migration that might occur. The three sheets were then sandwiched between two sheets of aluminum foil cut to 4 inches*4 inches. This 5-layer sample sandwich assembly was repeated 5 times and stacked one on top of the other in a pile and then placed under a 4-inch square block weighing 408 grams (0.9 lbs.) and placed in an oven at 600°C for 4 hours. After oven exposure, each construction was removed from the oven and cooled to room temperature. Each sample sandwich assembly was removed separately, the aluminum foil and blotting paper were removed so that the stain-absorbing sheet and the back side of the barrier paper could be assessed for any oil migration that may have come through the sheet. The number of spots and the % area were then recorded.

[044] Hot Coffee Cup Test: Hot coffee with brewed cream and / or heated to 95 °C was poured into a paper cup formed for 30 minutes. The cup was then inspected for any leaks after the 30-minute test period. No leaks is considered approved.

[045] Determination of the shear storage modulus curve: The TA RDA instrument model ARES G2 was used to generate the shear storage modulus of the dry film. An 8 mm or 25 mm parallel plate geometry was used to conduct the temperature sweep run on the RDA instrument from 0 °C to 150 °C at a ramp rate of 5 °C / min, at an angular frequency of 10 rads / sec, and in self-tension and self-strain mode. A sample film was prepared by molding approximately 4 to 5 grams of a wet sample into a 5 cm diameter releasable silicone rubber cup. The filled cup was then placed in an oven at 50 °C for 24 hours, followed by the application of a vacuum at 50 °C for another 24 hours to remove residual water from the film. The resulting dry film is approximately 0.8 to 1.5 mm thick. Once Petition 870220102292, dated 04 / 11 / 2022, page 33 / 52 21 / 28 where the shear modulus curve is generated, the modulus in the following three temperature ranges was recorded for comparison: 50 °C to 60 °C, 80 °C to 90 °C and 100 °C to 110 °C.

[046] Ink overprint capability: the ACTEGA North America Performa aqueous flexo ink system was used to perform overprinting of the dry aqueous barrier coatings of this invention. Defect-free dehumidified surface and good tape adhesion was achieved with 3M #810 tape in accordance with ASTM F2252-03.

[047] The aqueous barrier coating compositions of Example 1 to Example 5 and Comparative Example 1 to Comparative Example 3 are listed in Table 1. Comparative Example 4 is the extruded LDPE that is in the 18-point Clearwater panel with approximately 7.2 lbs / MSF (35.2 g / m2) of LDPE. The components of the exemplary compositions according to the present invention were prepared by adding the acrylic copolymer and antifoaming agent dispersion(s) to a suitably sized high-density polyethylene plastic container and adding the remaining ingredients one at a time while mixing with a toothed mixing propeller at an average speed of 700 rpm. The entire composition was then mixed for 30–60 minutes to achieve a stable viscosity. % solids, viscosity, and pH were measured according to the methods described above.

[048] For a coating system (aqueous barrier coatings), each composition was applied with a rod wrapped with #18 wire on an 18-point Westrock SBS stock and dried at 90-100 °C for 30 seconds before handling and allowed to cool and remain overnight before performing any physical testing. The weight range of the applied dry coating is between 15 and 22 g / m2. TABLE 1 Compositions for Examples 1 to 5 and Examples Comparisons 1 to 3 Ingredient Chemical type and melting point or Tg Example 1 Example 2 Example 3 Example 4 Comparison Example 1 Example Comparison 2 Example Comparison 3 Example 5 Petition 870220102292, dated 04 / 11 / 2022, page 34 / 52 22 / 28 33% Solid Neutralized Amine Primacor Copolymer* Dispersion Polymer EAA Crystalline mp 75C 92.00 92.00 84.00 80.00 89.50 Mallard Tykote 6160 Acrylic Copolymer Tg +7 C 45.00 Royal Adhesives Paracryl 8936 Modified Styrenated Acrylic Copolymer Tg +18 C 27.25 Mallard Creek Tykote 1019 SBR, Tg +14 C 85.00 BASF HSL 9010 Modified Acrylic Copolymer, Tg -10 C 92.85 BYK AQUCER 8335 (Paraffin) Paraffin, MP 58 C. 17.00 BYK Aqucer, 561 Wax Emulsion Beeswax, MP 65 C 8.00 4.00 5.00 Micro Powder Microklear 418 Carnauba, mp 84 C 1.00 1.45 SASOL C80-G Cera Cera FischerTropsch, mp 85 C 0.25 0.30 Microenergy Microspray 2 30-50 Polyethylene Wax mp 114 C 3.00 Aqua Polysilk 19 Micro Powder Polyethylene, PTFE and Amide mp 102-118 C 2.00 Aquacer1547 Oxidized PE, MP 125 C 5.00 3.00 Micro Powder Microspray 6550 PE / Amide, mp 124-135 C 15.00 Superslide 904 Micro Powder Polyefin / Amide, mp138-145 C 12.00 10.00 BYK AQUAMAT 8731 EBS Wax, MP 142 C 4.50 Imerys Mistron Monomix Talc 7.00 BYKZAC 15% Zinc Oxide Solution 0.5 Esmeralda FoamBlast 327 Defoamer 1.00 Evonik Surfonyl 440 Humectant 1.00 0.25 Nouryon Alcogum L-29 Thickener 0.50 Ashland Benecel™ A4C Methylcellulose Thickener 0.40 Water Diluent 2.25 5.00 3.00 Total 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 pH 8.1 8.5 8.2 9.6 7.41 8.4 8.3 % Solids 36.52 36.30 41.39 52.00 45.80 39.42 34.37 Viscosity, cps 1030 194 440 950 250 3700 855 % by weight total crystalline 100.00 97.25 99.00 95.00 19.00 6.75 15.00 97.00. Petition 870220102292, dated 04 / 11 / 2022, page 35 / 52 23 / 28 * Primacor copolymer from SKGlobal Chemical with 18-22% by weight of acrylic acid and a melting index (MI) of 1250-1350 g / 10 min. at 190°C per ASTM D1238

[049] For two coating systems (sealing primer and aqueous barrier coating), the aqueous sealing primer was coated with a rod wrapped with #10 wire on 18-point Westrock SBS stock and dried at 90-100 °C for 30 seconds followed by aqueous barrier coatings using a rod wrapped with #8 wire and dried at 90-100 °C for 30 seconds. It was cooled and left overnight before any physical testing was performed. The aqueous sealing primer used for this invention was prepared by mixing 40% by weight of Royal Adhesives Hydra Fast 20915-DC20915 (acrylic emulsion), 20.5% water, 0.6% by weight of Ashland A4C Methyl Cellulose (thickener), 8.5% by weight of KaMin LLC, Polyplate HMT, 8.5% by weight of Imerys Mistron Monomix and 22.4% by weight of Hydra Fast 20915-DC20915 resulting in 48.75% solids, a pH value of 9.34 and an average viscosity of 360 cps.

[050] The performance properties of the innovative examples and comparative examples for a coating are listed in Table 2. TABLE 2 Performance properties of compositions for single coating system. Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Example 5 Comparative Example 4 (LDPE) Cobb Test 30 min. grams / m2 2.15 1.72 1.96 1.05 4.89 10.2 13.0 1.6 1.56 Test Kit 3M Test Kit 12 Approved Approved Approved Approved Approved Approved Approved Approved Approved Oil Stain Test Approved Approved Approved Approved Approved Approved Approved Approved Approved Face-to-Bottom Hot Seal 100% Fiber Tear 100% Fiber Tear 100% Fiber Tear 100% Fiber Tear No Seal* No Seal* 100% Fiber Tear Excellent Blockage Resistance Rating 3-4 3-4 4-5 4-5 2 4-5 2-3, sticky surface 4-5 5 Petition 870220102292, dated 04 / 11 / 2022, pp. 36 / 52 24 / 28 Cup Manufacturing Failed Failed Good Good Failed Failed Failed Good Good Hot Coffee Test Cannot be tested Failed Passed Passed Cannot be tested Cannot be tested Cannot be tested Passed Passed Overprinting Ability Good Good Good Good Good Good Good Good Good Face-to-Face Heat Sealing 100% fiber tear 100% fiber tear 100% fiber tear 100% fiber tear Not tested Not tested Not tested 100% fiber tear Not available *100% fiber tear sealing was only possible at an interface sealing temperature of 200-215 °C.

[051] In general, 30-minute Cobb test values ​​of 10 grams per square meter (g / m2) or less are considered good and 5 g / m2 or less are considered excellent; any values ​​above 12 g / m2 are considered to compromise water resistance for prospective end use. Based on the results listed in Table 2, although all innovative examples and comparative examples showed good 30-minute Cobb values ​​(water resistance), except for Comparative Example 3, which had a higher 3M kit value of 12 (grease resistance), pass-through oil stain test, and good overprinting capability, they exhibited different performance regarding heat sealing capability, blockage resistance, cup-making capability, and hot coffee leakage resistance.Note that comparative example 4 is a commercially available 18-point Clearwater panel with approximately 7.2 lbs / MSF (35.2 g / m2) of LDPE which is considered non-recyclable and is what the current innovative composition attempts to replace. Example 1 is 100% by weight of total crystalline but uses a crystalline active filler with a melting point (MP) of 58 °C (below 70 °C), which resulted in being slightly worse in block strength (rating of 34) as well as a much lower shear storage modulus in the 50 °C to 80 °C range (FIG. 7) and cannot provide adequate cup-making capacity and perform the hot coffee test. While Example 2 attempted to use two additional waxes with MP above 70 °C (84 & 85 °C) and the zinc oxide crosslinking agent to increase the modulus curve. Petition 870220102292, dated 04 / 11 / 2022, p. 37 / 52 25 / 28 of the overall shear storage modulus compared to Example 1 (FIG. 7), its shear storage modulus in the 80 °C to 110 °C range is still lower than that of LDPE. This resulted in the recrystallization rate or force not being high enough to allow the formation of consistent cups. The hot coffee test was performed on some of the good cups and the sealing lines showed obvious leakage staining. Higher MP waxes, higher % by weight of wax and with various wax combinations were used in Example 3 to Example 5. The higher % by weight of wax and the higher melting point caused the overall shear storage modulus curves to shift upwards to be slightly above the LDPE curve. These three different wax combinations from Example 3 to Example 5 produced an almost overlapping shear storage modulus cure in the 30 °C to 110 °C range.The overall shear modulus curves for Example 3 through Example 5 exhibited good block strength (rating 4 to 5), 100% fiber tear seal, good cup-forming performance, and good hot coffee resistance comparable to those of commercial LDPE polyextruded sheets.

[052] To demonstrate this when both main sides of the substrate are coated with the innovative aqueous barrier coating composition, as shown in FIG. 3. Face-to-face seals were also performed for Example 1 to Example 5 with 100% fiber tear seals in the last row in Table 2.

[053] Comparative Example 1 and Comparative Example 2 used dispersions of non-crystallinity acrylic binders with Tgs of -10 °C to 18 °C, which are typically used in heat-sealable applications. Waxes were used to balance sealing capacity as well as block strength. Comparative Example 1 did not show heat-sealability under a standard heat-seal interface temperature of 190-195 °C, which affected cup success and 100% fiber tear-out only. Petition 870220102292, dated 04 / 11 / 2022, page 38 / 52 26 / 28 is possible at a sealing interface temperature of 200-215 °C. The shear storage modulus curve of Comparative Example 1 showed two sudden dips, one from lower MP wax and one from acrylic binder (possibly lower molecular weight), and the curve also has a lower shear storage modulus across the entire temperature range. Even if higher loading of high-temperature waxes might shift the curve upwards as in the previous example, this would only make the thermal seal worse than it is. Comparative Example 2 also showed no hot sealing capability under standard hot sealing conditions, and high temperature is required to achieve 100% fiber tear, thus also affecting its cup manufacturing efficiency.However, its shear storage modulus curve showed only a slight reduction with increasing temperature compared to that of LDPE and does not allow the polymer to readily flow out at the hot sealing temperature to have a good fiber tear seal. In this case, the polymer composition does not exhibit adequate melt flow at the sealing temperature for rapid bond formation and development. Reducing the % by weight of wax will cause blockage problems, even if it may help promote the melt flow of the polymer composition. Without crystallinity in the polymer binder, the composition did not have a fast enough melt flow to promote bond formation, nor did it develop a fast enough bond during the cooling step in the cup manufacturing process.

[054] Comparative Example 3 used a softer non-crystalline SBR binder dispersion, so the composition may allow the use of higher melting point waxes to balance sealing ability and block strength. Due to the SBR polymer, the surface remains tacky even though higher mp waxes and higher fillers were used. Its shear storage curve also proved to be flat in the hot sealing temperature range for good Petition 870220102292, dated 04 / 11 / 2022, pp. 39 / 52 27 / 28 Melt flow development. Without crystallinity in the polymer binder, the composition did not have a melt flow fast enough to promote bond formation, nor did bonds develop quickly enough during the cooling step in the cup manufacturing process.

[055] The results of coating system 2 (aqueous sealing primer followed by aqueous barrier coatings) are listed in Table 3. The aqueous sealing primer used is described previously. Except for the 30-minute Cobb values, all other property test results exactly echo the same trends as the single-coating system. Here, Comparative Example 2 is the only one that exceeds 10 g / m2. The shear storage modulus curve is applicable only to the aqueous barrier coating itself. TABLE 3. Performance properties of compositions for double coating system. Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Example 5 Cobb Test 30 min.grams / m2 6.84 9.28 4.43 3.66 6.92 17.8 2.54 3.32 Test Kit 3M Test Kit 12 Approved Approved Approved Approved Approved Approved Approved Approved Oil Stain Test Approved Approved Approved Approved Approved Approved Approved Face-to-Bottom Heat Seal 100% fiber tear 100% fiber tear 100% fiber tear 100% fiber tear No Seal No Seal 100% fiber tear 100% fiber tear Block Strength Rating 3-4 3 4-5 4-5 2 5 2-3, sticky surface 4-5 Cup Fabrication Failed Failed Approved Approved Failed Failed Failed Approved Overprint Ability Failed Failed Approved Approved Cannot Cannot be tested Cannot be tested Cannot be tested Approved Face-to-Face Heat Seal 100% fiber tear 100% fiber tear 100% fiber tear 100% fiber tear Not tested Not tested Not tested 100% fiber tear. *100% fiber tear sealing was only possible at an interface sealing temperature of 200-215 °C. Petition 870220102292, dated 04 / 11 / 2022, pp. 40 / 52 28 / 28

[056] A cellulosic substrate coated with the aforementioned inventive aqueous barrier coating with or without the optional sealing primer provides easy repulping and recycling capability, good heat sealing capability, resistance to roll blockage, container forming characteristic, good barrier to water (including hot water and hot coffee), oils and greasy liquids, as well as exhibiting good overprinting capability.

[057] Many modifications and variations may be made without departing from its spirit and scope, as will be evident to those skilled in the art. The specific embodiments described herein are offered only as examples, and the invention shall be limited only by the terms of the appended claims, together with the full scope of the equivalents to which such claims are entitled. Petition 870220102292, dated 04 / 11 / 2022, pp. 41 / 52

Claims

1 / 4 CLAIMS 1. Aqueous barrier coating for mold-formable cellulosic substrates characterized in that said coating is polyurethane-free and comprises as components: A) at least one polymer binder dispersion comprising 40% to 95% by weight of the coating; B) at least one active filler comprising 3% to 30% by weight of the coating; and C) one or more optional additives, wherein crystallinity is present in at least one of component A) and component B); and wherein a dry film resulting from the coating has a shear storage modulus between 50°C and 60°C in the range of 1.5x10⁶ to 1χ10⁹ Pascal, a shear storage modulus between 80°C and 90°C in the range of 2x10⁵ to 5x10⁷ Pascal, and a shear storage modulus between 100°C and 110°C in the range of 5χ10³ to 1χ10⁶ Pascal.

2. Aqueous barrier coating, according to claim 1, characterized in that the combined weight percentage of component A) and component B) is greater than 50% by weight of the total coating weight.

3. Aqueous barrier coating, according to claim 2, characterized in that the combined weight percentage of component A) and component B) is greater than 60% by weight of the total coating weight.

4. Aqueous barrier coating, according to claim 2, characterized in that the combined weight percentage of component A) and component B) is greater than 65% by weight of the total coating weight. Petition 870240099183, dated 11 / 21 / 2024, page 12 / 19 2 / 4 5. Aqueous barrier coating, according to claim 1, characterized in that the melting point of the crystalline phase of component A) is in the range of 50°C to 140°C.

6. Aqueous barrier coating, according to claim 1, characterized in that component B) is a dry wax or a pre-dispersed wax with a melting point of its crystalline phase in the range of 70°C to 145°C.

7. Aqueous barrier coating according to claim 1, characterized in that crystallinity is present in component A).

8. Aqueous barrier coating, according to claim 7, characterized in that component A) is selected from the group consisting of ethylene-containing homopolymer and water-stabilized copolymers, ethylene-acrylic acid (EAA) copolymers, ethylene-methacrylic acid copolymers, ethylene / itaconic acid copolymers, ethylene / methyl hydrogen maleate copolymers, ethylene / maleic acid copolymers, ethylene / acrylic acid / methyl methacrylate terpolymers, ethylene / acrylic acid / ethyl acrylate terpolymers, ethylene / methacrylic acid / ethyl acrylate terpolymers, ethylene / itaconic acid / methyl methacrylate terpolymers, ethylene / methyl hydrogen, maleate / ethyl acrylate terpolymers, ethylene / acrylic acid / vinyl acetate terpolymers, ethylene / methacrylic acid / vinyl acetate terpolymers, terpolymers ethylene / acrylic acid / vinyl alcohol terpolymers, ethylene / propylene / acrylic acid terpolymers,ethylene / acrylamide / acrylic acid terpolymers, ethylene / styrene / acrylic acid terpolymers, ethylene / methacrylic acid / acrylonitrile terpolymers, ethylene / fumaric acid / methyl vinyl ether terpolymers, ethylene / vinyl chloride / acrylic acid terpolymers, ethylene / vinylidene chloride / acrylic acid terpolymers, polyethylene / acrylic acid graft copolymers, polyethylene / methacrylic acid graft copolymers, ethylene / propylene / acrylic acid polymerized graft terpolymers; fatty acid-modified polyester terephthalate (PET) and high-oil-modified soft polyester terephthalate (PET).

9. Cellulosic substrate coated with the aqueous barrier coating as defined in claim 1, characterized in that the coating is applied to at least one of the first and second principal sides of the cellulosic substrate.

10. Cellulosic substrate, according to claim 9, characterized in that the total dry weight of said coating is in the range of 3 g / m3 to 35 g / m3.

11. Cellulosic substrate, according to claim 10, characterized in that the total dry weight of said coating is in the range of 5 g / m3 to 25 g / m3.

12. Cellulosic substrate, according to claim 10, characterized in that the total dry weight of said coating is in the range of 8 g / m3 to 25 g / m3.

13. Cellulosic substrate, according to claim 9, characterized in that the dry weight of said coating is in the range of 12 g / m3 to 35 g / m3.

14. Cellulosic substrate, according to claim 13, characterized in that the dry weight of said coating is in the range of 13 g / m3 to 28 g / m3.

15. Cellulosic substrate, according to claim 13, characterized in that the dry weight of said coating is in the range of 15 g / m3 to 25 g / m3.

16. Cellulosic substrate, according to claim 9, characterized in that it further comprises an aqueous sealing primer applied and dried on at least one of the main sides onto which the coating is to be subsequently applied. Petition 870240099183, dated 11 / 21 / 2024, page 14 / 19 4 / 4 17. Cellulosic substrate, according to claim 16, characterized in that the aqueous sealing primer comprises: A) at least one aqueous dispersion of polymer binder comprising 30% to 90% by weight of the coating; B) at least one particulate filler comprising 5% to 60% by weight and selected from the group consisting of coating-grade clays, calcium carbonate, talc, barium sulfate, zinc sulfate, aluminum sulfate, reaction products of calcium oxide, titanium dioxide, lithopone, zinc sulfide, alumina, silica, sodium hexametaphosphate, and mineral particles pre-treated with polymer binder; and C) at least one optional additive.

18. Cellulosic substrate, according to claim 16, characterized in that the dry weight of the aqueous barrier coating is in a range of 3 g / m3 to 15 g / m3 and the dry weight of the aqueous sealing primer is in a range of 3 g / m3 to 15 g / m3.

19. Cellulosic substrate, according to claim 9, characterized in that the substrate has an uncoated base weight in a range of 40 pounds to 300 pounds per ft².

20. Cellulosic substrate, according to claim 9, characterized in that the substrate is a cardboard substrate with a gauge thickness in a range of 4 points to 30 points. Petition 870240099183, dated 11 / 21 / 2024, p. 15 / 19

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