Modified cellulose-based barrier coating composition

Abstract

An aqueous modified cellulose-based high barrier coating composition and method for making same comprises modified cellulose (e.g., sodium carboxymethylcellulose and / or hydroxy propyl methyl cellulose), water, plasticizer, crosslinking agent, and hydrophobic agent, with a weight ratio of water: modified cellulose of about 2:1 to about 999:1, with a weight ratio of plasticizer: modified cellulose of about 1:1,000 to about 1:1, with a weight ratio of crosslinking agent: modified cellulose of about 1:1,000 to about 1:10, with a weight ratio of hydrophobic agent: modified cellulose of about 1:1,000 to about 1:5, and some embodiments comprise castor oil and sodium silicate (40%). The coatings of the disclosure may be used with cups, bowls, plates, straws, agricultural films, corrugated boxes, paper mailers, and flexible materials.

Description

MODIFIED CELLULOSE-BASED BARRIER COATING COMPOSITIONTECHNICAL FIELD

[0001] The present disclosure relates to modified-cellulose-based biodegradable and / or compostable barrier coatings (e.g., for paper and other pulp fiber related substrates) as well as methods of manufacturing and using the same, as well as articles using the barrier coating of the present disclosure. More particularly, the present disclosure comprises formulations that offer excellent oil and grease resistance at low dry coat weights, heat sealability, oxygen barrier, and water vapor barrier.BACKGROUND OF THE INVENTION

[0002] Paper products play an essential role in our daily lives due to their low cost, environment- friendly character, renewability, and recyclability. However, paper produced from cellulose is hydrophilic and porous, leading to low resistance to both water and oils. Several approaches have been used to improve water and oil resistance, such as hydrophobic agents. Historically, poly-fluoroalkyl substances (PFAS) have been used as coating materials, but PFAS are likely carcinogenic to humans and have significant environmental problems.

[0003] Nowadays, synthetic petroleum-based plastic lamination or coating is commonly used to improve water and oil resistance. For example, polyethylene is commonly used on paper substrates for liquid repellency. While currently thought to be non-toxic, challenges remain in terms of the separation of coating materials from paper or pulp fiber during recycling / repulping. Further, many of these plastic coatings are not biodegradable.

[0004] PLA is a bio-based plastic commonly used to coat or laminate paper. Still, it is a costly materialand is not biodegradable under ambient conditions. It has similar separation problems as synthetic plastic coatings, preventing recycling of the paper product or making it cost-prohibitive. Latex is also used to improve water resistance but has poor oil resistance; further, latex is synthetic, non- biodegradable, and may easily leach into food products and water, posing a significant health and environmental impact threat.

[0005] In addition to non-biodegradability, the other major problem of synthetic petroleum-based plastic and latex-coated paper is that they can create a tremendous amount of microplastics, either passively during mechanical breakdown over time in the environment, or during recycling / repulping operations. Microplastics are thought to be a significant health concern and may bioaccumulate in humans and other plant and animal life.BRIEF SUMMARY OF THE INVENTION

[0006] Disclosed herein is a modified cellulose-based barrier coating composition comprising a modified cellulose component (e.g., sodium carboxymethylcellulose and / or hydroxy propyl methyl cellulose), plasticizer component, crosslinking agent, hydrophobic agent, and water, with a weight ratio of water: modified cellulose of about 2: 1 to about 999: 1, with a weight ratio of plasticizer: modified cellulose of about 1: 1 to about 1: 1,000, with a weight ratio of crosslinking agent: modified cellulose of about 1:10 to about 1: 1,000, and with a weight ratio of hydrophobic agent: modified cellulose of about 1:5 to about 1:1,000. The amount of hydrophobic agent in the coating composition may range from 0.1 wt% to 40 wt%. In some embodiments, the amount may be 0.1 wt%, 0.25 wt%, 0.5 wt%, 0.75 wt%, 1.0 wt%, 1.5 wt%, 2.0 wt%, 2.5 wt%, 3.0 wt%, 3.5 wt%, 4.0 wt%, 4.5 wt%, 5.0 wt%, 6.0 wt%, 7.0 wt%, 8.0 wt%, 9.0 wt%, 10.0 wt%, 12.5 wt%, 15.0 wt%, 17.5 wt%, 20.0 wt%,22.5 wt%, 25.0 wt%, 27.5 wt%, 30.0 wt%, 32.5 wt%, 35.0 wt%, 37.5 wt%, or 40.0 wt%.

[0007] In various embodiments, the weight percent may fall within one or more of the following sub-ranges: 0. 1-1.0 wt%, 0.5-5.0 wt%, 1.0-10.0 wt%, 5.0-15.0 wt%, 10.0-20.0 wt%, 15.0-25.0 wt%, 20.0-30.0 wt%, or 25.0-40.0 wt%. Selection of the specific amount may depend on the function of the hydrophobic agent, its interaction with the modified cellulose matrix, and the intended level of oil, grease, or water resistance.

[0008] Here, the disclosed technology and newly synthesized cellulose-based bioplastic is an aqueous coating composition that can be applied on paper products to create a hydrophobic plastic layer on the surface of the paper. In some embodiments, it appears glossy like a petroleum-based polyethylene coating layer; in others, it offers an oxygen and water vapor barrier that can be used as a coating on paper and other food packaging, such as cups and plates. The cellulose-based bioplastic coatings and papers using the same of the present disclosure are in most embodiments, biodegradable, compostable, recyclable, and repulpable without the need to separate the bioplastic from coated paper. There will be no chance of creating any microplastic because the bioplastic is synthesized from fully biodegradable cellulose-based pulp fiber. The cellulose-based bioplastic coatings and papers using the same of the present disclosure are in most embodiments, grease and oil resistant and heat sealable, depending on the thickness of the coating applied and the quality of the substrate, e.g., the tightness of the fibers in the substrate.

[0009] In additional embodiments, the coatings provide excellent oil and grease resistance at low dry coat weights (e.g., as low as 6 gsm), demonstrating extended olive oil retention performance for more 24 hours, and even more than 15 days. In such compositions, the use of castor oil and sodium silicate (40%) may further enhance barrier properties.

[0010] Further disclosed herein is a method of making a modified cellulose-based barriercoating composition, and the method comprises mixing modified cellulose component, plasticizer, crosslinking agent, hydrophobic agent, and water at a suitable temperature for a sufficient time to form the modified cellulose-based carrier coating composition. A suitable mixing or formulation temperature may be from about 1°C to about 300°C, e.g., from about 10°C to about 250°C, e.g., from about 15°C to about 200°C or e.g., from about 20°C to about 150°C. And the mixing or formulation time may be from about 0.01 minute to about 10,000 minutes, e.g., from about 0. 1 minute to about 1000 minutes, or e.g., from about Iminute to about 100 minutes.

[0011] Further disclosed herein is a composition that can comprise a modified cellulose component that comprises carboxymethylcellulose (CMC) and / or an alkaline metal salt of carboxymethylcellulose (e.g., sodium CMC) and / or hydroxy propyl methyl cellulose (HPMC); a plasticizer component that comprises glycerol or sorbitol; a crosslinking agent component that comprises a glyoxal or N-hydroxymethyl acrylamide; a hydrophobic agent component that comprises alkyl ketene dimers (AKDs), polydimethylsiloxane (PDMS), silicon dioxide, calcium silicate, trichloro(octadecyl)silane (TOS), ethyl 2-cyanoacrylate, chitosan, wax, etc.

[0012] Further disclosed herein is a method of making an aqueous modified cellulosic-based coating composition comprising contacting modified cellulose component with water to form a modified cellulose solution; and contacting the modified cellulose solution with a plasticizer component, crosslinking agent component, and hydrophobic agent component to form the aqueous modified cellulosic -based barrier coating composition.

[0013] Also disclosed is a composition that comprises CMC, sorbitol, AKD, glycerol, castor oil, and sodium silicate (40%), where the coating exhibits excellent oil and grease resistance at dry coat weights from 1 gsm to 10 gsm, with olive oil retention lasting over 24 hours andeven 15 days. Such compositions may be used as alternatives to traditional synthetic coatings in food service applications.

[0014] Further disclosed herein is a method of making coated paper comprising coating a dry paper sheet surface with a modified cellulosic-based barrier coating composition; wherein a weight ratio of paper sheet: modified cellulosic-based barrier coating is from about 60:40 to about 99.9:0.1.

[0015] Other features and advantages of the present invention will become apparent from the following detailed description, including the drawing. It should be understood, however, that the detailed description and the specific examples, while indicating preferred embodiments, are provided for illustration only, because various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from the detailed description.BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention is illustrated by way of examples and not limited solely to the accompanying drawings, in which like references generally indicate similar elements or features.

[0017] FIG. 1 depicts a schematic of an example method of the present disclosure to formulate an example coating (Coating A) of the present disclosure;

[0018] FIG. 2 depicts a schematic of an example method of the present disclosure to formulate an example coating (Coating B) of the present disclosure;

[0019] FIG. 3 depicts a schematic of an example method of the present disclosure to formulate an example coating (Coating C) of the present disclosure.

[0020] FIG. 4 depicts a schematic of an example method of the present disclosure to formulate an example coating (Coating D) of the present disclosure.DETAILED DESCRIPTION

[0021] Definitions. The terns used in this specification generally have their ordinary meanings in the art, within the context of this subject matter and in the specific context where each term is used. Certain terms are defined below to provide additional guidance in describing the compositions and methods of the disclosed subject matter and how to make and use them.

[0022] As used in the specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a compound” includes mixtures of compounds.

[0023] It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present application. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the application as set forth in the appended claims.

[0024] Modified Cellulose. To solve the problems inherent in plastic coated water and oil / grease resistant paper and other textiles, we have developed a coating based on, e.g., carboxymethyl cellulose (CMC) and / or salts of carboxymethyl cellulose that is less expensive, nontoxic, biodegradable, and / or compostable.

[0025] In general, modified cellulose compounds, which add side groups to the cellulose chain backbone that are thought to sterically hinder hydrogen bonding between side chains, and allow solubility in water, allowing for ease of dispersion onto the surface of paper and other textile products may be suitable for use in the present invention. Modified cellulose compounds also usually retain their biodegradability and / or compostability.

[0026] For example, CMC is widely used in foods and consumer products as a non-toxic thickener.CMC properties may be varied depending on the degree of substitution of hydroxyl groups on cellulose by polar carboxymethyl groups during synthesis between cellulose and chloroacetic acid or sodium chloroacetate, which makes the cellulose soluble; as well as the underlying length of the cellulose chains being modified (which can affect overall viscosity); as well as the amount of salts present in the mixture, which can be varied by the amount of purification after the usual alkali-catalyzed reaction of cellulose with chloroacetic acid; as well as temperature and acidity when in aqueous solution.

[0027] Throughout the application, for ease of reference, carboxymethyl cellulose and / or salts of carboxymethyl cellulose is abbreviated as “CMC” throughout, unless specifically noted. Salts of carboxymethyl cellulose may include any suitable alkaline metal salt, such as CMC-Na or CMC-K, CMC-Ca, CMC-Mg, and other suitable salts known in the art, of various suitable purities, backbone structures, sizes and final viscosities, unless otherwise specifically specified.

[0028] In embodiments of the present invention, various types of CMC and / or CMC-Na and / or alkaline metal or other salts of CMC may be used. For example, low, medium and high viscosity and / or molecular weight type carboxymethyl cellulose and / or carboxymethyl cellulose-sodium can be used as raw material in the synthesis of natural binder. In some aspects, the CMC is dissolved into water to prepare CMC solution.

[0029] Crosslinking Agent. In some embodiments, glyoxal may be used in combination with CMC and other agents discussed below. Glyoxal treatments (most commonly added as a 40% aqueous solution) are used as a crosslinking agents and can improve the wet strength of paper, alone or with catalysts such as Zn(NCh). along with and other dry strength agents such as chitosan (see, e.g., Chen et al. (2013) BioResources 8(4), 6087-6096). Other crosslinking agents such as N-hydroxy methyl acrylamide, GPAM (glyoxylate polyacrylamide), and / or PAE (polyamide epichlorohydrin)may also be used.

[0030] Plasticizers. Plasticizers such as glycerol and sorb i lol may be used. Glycerol and combinations of glycerol and sorbitol have been used to improve flexibility, strength, shine, vapor barrier, and hydrophobicity of starch-based biodegradable films (See e.g., Gonzalez-Torres, et al. Polymers 2021 13, 3356) may be used. Other plasticizers may include xylitol, mannitol, PEG, ethylene glycol and propylene glycol.

[0031] In some embodiments, CMC, glyoxal solution and glycerol may be applied to paper products. In others, further plasticizers, modified celluloses such as HPMC, and sizing agents may be added or used in lieu of the CMC, glyoxal and glycerol solution to convey desired properties.

[0032] Another Modified Cellulose, hydroxy Propyl Methyl Cellulose (HPMC) has been used in some applications as film-forming protective coating, with low permeability to oxygen, carbon dioxide and lipids, often incorporating plasticizers (See, e.g. Khwaldia (2013) BioResources 8(3), 3438-3452.)Hydrophobic Agent. Alkyl ketene dimer (AKD) emulsion has been used in the paper industry as a hydrophobic / sizing agent. AKD is a biodegradable wax. Other hydrophobic agent and internal sizing agents such as hydrophobic starches, polydimethylsiloxane (PDMS), silicon dioxide, calcium chloride, trichloro(octadecyl)silane (TOS), ethyl 2-cyanoacrylate, chitosan, wax, and gelatin may be used in some embodiments.

[0033] Oil Resistance Test Definition: The oil resistance test is performed by applying a selected quantity of oil directly onto the surface of the coated substrate and allowing it to remain in contact for a predetermined period of time under ambient or controlled conditions. The substrate is maintained at a desired temperature and pressure, which may be standard atmospheric pressure unless otherwise specified. At the conclusion of the test period, the coated substrate is visually inspected with the naked eye to determine whether the oil has penetrated the coating and reached the underlying substrate.Evidence of discoloration, translucency, or saturation of the substrate indicates oil penetration and failure of the barrier, whereas absence of such signs indicates effective oil resistance.

[0034] Example Coating A. An example embodiment of the present disclosure (“Coating A”) was prepared using the following exemplary method. A schematic of the method is given in Figure 1.

[0035] A total of 43 g of water was added into a beaker. Next, 7 g of CMC was added and the mixture heated to 100 °C while continuously stirring until the CMC was completely dissolved, approximately 10-15 minutes. Next, water was added to re-adjust the weight to make up for water lost from evaporation.

[0036] To the resultant solution, 7 g of glyoxal Solution (40%) was added and mixed at approximately 60 °C for 30 minutes. Next, 0.5 g of glycerol was added and mixed for 30 minutes.

[0037] In a separate beaker, 46.5 g of water was placed into the beaker. A total of 3.5 g of hydroxy propyl methyl cellulose (HPMC) was added, and the solution heated to 80 °C while stirring continuously under obscivation and maintained at 80 °C for 10 minutes. At the end of the heating period, water was added to make up of water lost from evaporation, and then the mixture cooled down to room temperature, during which the white HPMC mixture turned clear.

[0038] The contents of the two beakers (Glyoxalated CMC with glycerol solution + HPMC solution) were combined and mixed for 30 minutes. Then, 5 g of sizing agent alkyl ketene dimer (AKD) emulsion was added and mixed thoroughly until uniformly dispersed.

[0039] Example Coating B. An example embodiment of the present disclosure (“Coating B”) was prepared using the following exemplary method. A schematic of the method is given in Figure 2.

[0040] A total of 43 g of water was added into a beaker. 7 g of CMC was added and the resulting mixture was heated to 100°C while continuously stirring until CMC was completely dissolved, approximately 10-15 minutes. Next, water was added to re-adjust the weight to make up for water lostfrom evaporation.

[0041] In a separate beaker, 46.5 g of water was placed into a beaker. Next, 3.5 g of HPMC was added, and the solution was heated to 80 °C while stirring continuously under observation and maintained at 80 °C for 10 minutes. At the end of the heating period, water was added to make up of water lost from evaporation, and then the mixture cooled down to room temperature, during which the white HPMC mixture turned clear.

[0042] In a third beaker, 50 g of water was added, followed by 50 g of sorbitol. This solution was heated at 80 °C and stirred continuously for 10-15 minutes until the sorbitol was completely dissolved.

[0043] A total of 20 mL of each solution (CMC, HPMC, sorbitol) were combmed and mixed thoroughly. To this solution, 3.5 g of glyoxal solution (40%) was added, then mixed at approximately 60°C for 30 minutes. Next, 0.5 g of glycerol was added to the solution and mixed for 30 minutes. Finally, 2.5 g of AKD emulsion was added and mixed thoroughly until uniformly dispersed.

[0044] Example Coating C. An example embodiment of the present disclosure (“Coating C”) was prepared using the following exemplary method. A schematic of the method is given in Figure 3.

[0045] A total of 88 g of water was added into a beaker. Next, 10 g of CMC was added to the mixture heated to 100°C under continuous stirring until the CMC was completely dissolved, approximately 10- 15 minutes. Next, water was added to re-adjust the weight to make up for water lost from evaporation.

[0046] After the CMC had completely dissolved, 25 g of sorbitol was added to the CMC solution. This solution was heated at 80 °C and stirred continuously for 10-15 minutes until the sorbitol was completely dissolved.

[0047] Next, 6 g of glyoxal solution (40%) was added and mixed at approximately 60°C for 30 minutes. A total of 1.0 g of glycerol was then added and the solution mixed for 30 minutes. Finally, 5 g AKD emulsion was added and mixed thoroughly until uniformly dispersed.

[0048]

[0000] Example Coating D. An example embodiment of the present disclosure (“Coating C”) was prepared using the following exemplary method. A schematic of the method is given in Figure 4.

[0049] A total of 42 g of water was added into a beaker. Next, 4g of HPMC was added to the mixture heated to 100°C under continuous stirring until the HPMC was completely dissolved, approximately 10-15 minutes. Next, water was added to re-adjust the weight to make up for water lost from evaporation.

[0050] After the HPMC had completely dissolved, 18 g of sorbitol and 5g Calcium Chloride were added to the HPMC solution. This solution was heated at 80 °C and stirred continuously for 10-15 minutes until the sorbitol was completely dissolved.

[0051] Next, 1g chitosan dissolved with 20g acidifying water ( diluted acetic acid or HC1 acid )

[0052] Next, 20g chitosan solution and 4 g of glyoxal solution (40%) was added and mixed at approximately 60°C for 30 minutes. A total of 1.0 g of glycerol was then added and the solution mixed for 30 minutes. Finally, 5 g AKD emulsion was added and mixed thoroughly until uniformly dispersed.Table 1 below provides the formulations for Coatings A, B, C and D.

[0053] Example 1. Application to PaperThe Cobb test of coated paper was performed according to follow Tappi standard method T441. The coated paper sample was weighed and placed under a vertical cylinder with an internal crosssection area of 100 cm2. The sample and cylinder rested on a rubber mat supported on a steel plate. Approx. 100 ml of water was poured into the cylinder. After 30 minutes, the water was poured out. Excess water was removed from the specimen using blotting paper and a roller. The specimen was weighed while wet and the amount of water absorbed by 1 m2of specimen material was calculated.

[0054] Example 2. Cobb Test (water absorption). The four example coatings were tested via theCobb test. The water absorption was determined by measuring the amount of water absorbed by paper within 60 s, 600 s and 1800 s (1, 10, 30 minutes). The Cobb 60 values were expressed in g / in2. Results are given in Table 2. “Control” was uncoated paper for comparison.Table 2. Cobb Test results for example embodiment coatings

[0055] Example 3. Heat sealing. The heat-sealing strength was measured according to ASTM F88.Heat sealing is the process of sealing one thermoplastic to another similar thermoplastic using heat and pressure. The direct contact method of heat sealing utilizes a constantly heated die or sealing bar to apply heat to a specific contact area or path to seal or weld the thermoplastics together. Heat sealing is used for many applications such as packaging.

[0056] Table 3 shows the heat-sealing properties of the three example coating formulations (A, B, C).Heat sealing refers to the ability of a coating to melt or melt bond with itself, thus allowing assembly of flat coated paper and other textile sheets to form three-dimensional structures such as cups and the like. Each embodiment may be advantageous for certain manufacturing situations. The times to seal as reported in Table 3 are the optimum times for obtaining the highest heat-seal bonding strength.Table 3. Heat Sealing properties (optimum times) of Example Embodiments.

[0057] Coating D exhibited minimal or no heat sealing.

[0058] Modified cellulose (CMC) was dissolved in boiling water. Further, a certain amount of Glyoxal Solution and Glycerol was added into the dissolved CMC solution and vigorously mixed to make CMC mixer solution. Further three different coating agents were prepared from the above mixer solution.

[0059] a) A part of the above CMC mixture solution was blended with hydroxy propyl methyl cellulose (HPMC) and AKD (alkyl ketene dimer) for testing the coating properties of paper substrates

[0060] b) A part of the above CMC mixture solution was blended with hydroxy propyl methyl cellulose (HPMC), Sorbitol, and AKD (alkyl ketene dimer) for testing the coating properties of paper substrates.

[0061] c) A part of the above CMC mixture solution was blended with Sorbitol, and AKD (alkyl ketene dimer) for testing the coating properties of paper substrates.

[0062] Paper substrates treated with above biodegradable and / or compostable coating compositions A- C showed excellent heat sealing and Coatings A-D high barrier properties and all are suitable as plastic coated paper that might potentially replace non-biodegradable plastic (polyethylene) coated cups, plates, and bowls, which create microplastic particles that are a health issue as well as contaminants that pollute water and the environment. The dried / cured coat weights may range from about 1-100 g / m2, from 3-50 g / m2, and from 5-40 g / m2.

[0063] Further disclosed herein is a method of making a modified cellulose -based barrier coating composition, and the method comprises mixing modified cellulose component, plasticizer, crosslinking agent, hydrophobic agent, and water at a suitable temperature for a sufficient time to form the modified cellulose-based carrier coating composition.

[0064] Also disclosed is a composition that comprises CMC, sorbitol, AKD, glycerol, castor oil, and sodium silicate (40%), where the coating exhibits excellent oil and grease resistance at dry coatweights as low as 6 from 1 gsm to 10 gsm, with olive oil retention lasting over 24 hours. Such compositions may be used as alternatives to traditional synthetic coatings in food service applications.

[0065] Further disclosed herein is a method of making a coated paper comprising coating a dry paper sheet surface with a modified cellulosic-based barrier coating composition; wherein a weight ratio of paper sheet: modified cellulosic-based barrier coating is from about 60:40 to about 99.9:0.1.

[0066] EXAMPLE COATING E

[0067] An aqueous barrier coating was prepared to enhance oil and grease resistance at low dry coat weights. The composition comprised: 7.5 wt% carboxymethyl cellulose (CMC), 9.0 wt% sorbitol, 3.6 wt% alkyl ketene dimer (AKD), 1.5 wt% glycerol, 7.5 wt% castor oil, and 20 wt% sodium silicate (40% solution), with the balance being water (55.9 wt%). The components were mixed under continuous stirring at 80°C for 30 minutes to form a homogenous solution.

[0068] The resulting formulation was applied to paper substrates and dried. At a dry coat weight of approximately 6 gsm, the coated paper retained olive oil for more 24 hours, and even more than 15 days. The coating demonstrated excellent oil and grease resistance.

[0069] In some embodiments, an aqueous cellulose-based barrier coating composition comprises a modified cellulose component, water, a plasticizer component, a crosslinking agent component, and a hydrophobic agent component. The weight ratio of water to modified cellulose may range from about 2:1 to about 999:1. The plasticizer component may be present in the aqueous cellulose-based coating composition in a weight ratio of plasticizer to modified cellulose of from about 1:1,000 to about 1:1. The crosslinking agent may be present in a weight ratio of crosslinking agent to modified cellulose of from about 1:1,000 to about 1:2. The hydrophobic agent may be present in a weight ratio of hydrophobic agent to modified cellulose of from about 1 : 1 ,000 to about 1:1.

[0070] The modified cellulose component may comprise carboxymethylcellulose (CMC), and / or an alkaline metal salt of carboxymethylcellulose (e.g., CMC-Na), and / or hydroxy propyl methyl cellulose (HPMC). The plasticizer component may include one or more of glycerol, sorbitol, xylitol, and mannitol. The crosslinking agent may include glyoxal, N-hydroxy methyl acrylamide, glyoxylatedpolyacrylamide (GPAM), or polyamide-epichlorohydrin (PAE). The hydrophobic agent may include alkyl ketene dimers (AKDs), polydimethylsiloxane (PDMS), silicon dioxide, calcium chloride, trichloro(octadecyl)silane (TOS), ethyl 2-cyanoacrylate, chitosan, and / or wax.

[0071] The amount of modified cellulose in the coating composition may range from 0. 1 wt% to 50 wt%. In some embodiments, the amount may be 0.1 wt%, 0.25 wt%, 0.5 wt%, 0.75 wt%, 1.0 wt%, 1.25 wt%, 1.5 wt%, 1.75 wt%, 2.0 wt%, 2.5 wt%, 3.0 wt%, 3.5 wt%, 4.0 wt%, 4.5 wt%, 5.0 wt%, 6.0 wt%, 7.0 wt%, 8.0 wt%, 9.0 wt%, 10.0 wt%, 12.5 wt%, 15.0 wt%, 17.5 wt%, 20.0 wt%, 22.5 wt%, 25.0 wt%, 27.5 wt%, 30.0 wt%, 32.5 wt%, 35.0 wt%, 37.5 wt%, 40.0 wt%, 42.5 wt%, 45.0 wt%, 47.5 wt%, or 50.0 wt%.

[0072] In various embodiments, the weight percent of modified cellulose may fall within one or more of the following sub-ranges: 0. 1-1.0 wt%, 0.5-5.0 wt%, 1.0-10.0 wt%, 5.0-15.0 wt%, 10.0-20.0 wt%, 15.0-25.0 wt%, 20.0-30.0 wt%, 25.0-40.0 wt%, 30.0-45.0 wt%, or 35.0- 50.0 wt%.

[0073] In some embodiments, the composition is provided in the form of an aqueous solution.The aqueous cellulose-based coating composition may comprise CMC in an amount of from about 0.1 wt% to about 50 wt%; plasticizer in an amount of from about 0.1 wt% to about 50 wt%;

[0074] crosslinking agent in an amount of from about 0.1 wt% to about 25 wt%;hydrophobic agent in an amount of from about 0.1 wt% to about 50 wt%.

[0075] The composition may be prepared by mixing carboxymethylcellulose, hydroxy propyl methyl cellulose, glycerol, sorbitol, glyoxal, and alkyl ketene dimers at a temperature of from about 1°C to about 300°C. Alternatively, the composition may be mixed for a duration of about 0.01 minutes to about 1,000 minutes.

[0076] In another embodiment, the aqueous cellulose-based coating composition is characterized by a degree of biodegradability equal to or greater than about 95%, determined according to ISO 17556:2003 E. The dried or cured coat weight of the aqueous coating may be from about 5 g / m2to about 30 g / m2, 5.00 g / m2, 5.25 g / m2, 5.50 g / m2, 5.75 g / m2, 6.00 g / m2, 6.25 g / m2, 6.50 g / m2, 6.75 g / m2, 7.00 g / m2, 7.25 g / m2, 7.50 g / m2, 7.75 g / m2, 8.00 g / m2, 8.25 g / m2, 8.50 g / m2, 8.75 g / m2, 9.00 g / m2, 9.25 g / m2, 9.50 g / m2, 9.75 g / m2, 10.00 g / m2, 10.25 g / m2, 10.50 g / m2, 10.75 g / m2, 11.00 g / m2, 11.25 g / m2, 11.50 g / m2, 11.75 g / m2, 12.00 g / m2, 12.25 g / m2, 12.50 g / m2, 12.75 g / m2, 13.00 g / m2, 13.25 g / m2,13.50 g / m2, 13.75 g / m2, 14.00 g / m2, 14.25 g / m2, 14.50 g / m2, 14.75 g / m2, 15.00 g / m2, 15.25 g / m2,15.50 g / m2, 15.75 g / m2, 16.00 g / m2, 16.25 g / m2, 16.50 g / m2, 16.75 g / m2, 17.00 g / m2, 17.25 g / m2,17.50 g / m2, 17.75 g / m2, 18.00 g / m2, 18.25 g / m2, 18.50 g / m2, 18.75 g / m2, 19.00 g / m2, 19.25 g / m2,19.50 g / m2, 19.75 g / m2, 20.00 g / m2, 20.25 g / m2, 20.50 g / m2, 20.75 g / m2, 21.00 g / m2, 21.25 g / m2,21.50 g / m2, 21.75 g / m2, 22.00 g / m2, 22.25 g / m2, 22.50 g / m2, 22.75 g / m2, 23.00 g / m2, 23.25 g / m2,23.50 g / m2, 23.75 g / m2, 24.00 g / m2, 24.25 g / m2, 24.50 g / m2, 24.75 g / m2, 25.00 g / m2, 25.25 g / m2,25.50 g / m2, 25.75 g / m2, 26.00 g / m2, 26.25 g / m2, 26.50 g / m2, 26.75 g / m2, 27.00 g / m2, 27.25 g / m2,27.50 g / m2, 27.75 g / m2, 28.00 g / m2, 28.25 g / m2, 28.50 g / m2, 28.75 g / m2, 29.00 g / m2, 29.25 g / m2,29.50 g / m2, 29.75 g / m2, or 30.00 g / m2.

[0077] In some cases, the coating forms a seal or weld to itself when dried and subjected to a pressure of 100 PSI at a temperature of 200°C for 0.7 seconds or less. The temperature and pressure can be in ranges from 75 PSI to 150 PSI, comprising approximately or about 75 PSI, 80 PSI, 85 PSI, 90 PSI, 95 PSI, 100 PSI, 105 PSI, 110 PSI, 115 PSI, 120 PSI, 125 PSI, 130 PSI, 135 PSI, 140 PSI, 145 PSI, to 150 PSI, depending on the equipment used and the desired sealing strength or test conditions. The temperature can be 150°C to 250°C, comprising approximately or about 150°C, 155°C, 160°C, 165°C, 170°C, 175°C, 180°C, 185°C, 190°C, 195°C, 200°C, 205°C, 210°C, 215°C, 220°C, 225°C, 230°C, 235°C, 240°C, 245°C, to 250°C, depending on the thermal sensitivity of the substrate and the desired bond strength or barrier performance. The time can be 0.1 seconds to 3 seconds, comprising approximately or about 0.1 seconds, 0.2 seconds, 0.3 seconds, 0.4 seconds, 0.5 seconds, 0.6 seconds,0.7 seconds, 0.8 seconds, 0.9 seconds, 1.0 second, 1.1 seconds, 1.2 seconds, 1.3 seconds, 1.4 seconds, 1.5 seconds, 1.6 seconds, 1.7 seconds, 1.8 seconds, 1.9 seconds, 2.0 seconds, 2.1 seconds, 2.2 seconds, 2.3 seconds, 2.4 seconds, 2.5 seconds, 2.6 seconds, 2.7 seconds, 2.8 seconds, 2.9 seconds, to 3.0 seconds, depending on the material properties, desired bond integrity, and specific application requirements.

[0078] The composition may be used to coat products including, but not limited to, cups, bowls, plates, straws, agricultural films, corrugated boxes, paper mailers, and flexible packaging materials.

[0079] A method of making the aqueous cellulose-based coating composition may include: (A) Forming a CMC solution by contacting CMC and / or CMC -Na with water; (B) Contacting the solution with glyoxal, glycerol, HPMC, and AKD to produce a composition with a ratio of CMC to water of 6.5:78.9, to glyoxal of 6.5:3, to glycerol of 6.5:0.5, to HPMC of 6.5:3.2, and to AKD of 6.5:0.75; (C) Alternatively, the CMC solution may be contacted with glyoxal, glycerol, HPMC, sorbitol, and AKD in a ratio of CMC to water of 3.2:64.5, to glyoxal of 3.2: 1.4, to glycerol of 3.2:0.5, to HPMC of 3.2: 1.6, to sorbitol of 3.2:23, and to AKD of 3.2:0.4; (D) Alternatively, the CMC solution may be contacted with glyoxal, glycerol, sorbitol, and AKD in a ratio of CMC to water of 7.4:65.2, to glyoxal of 7.4: 1.8, to glycerol of 7.4:0.7, to sorbitol of 7.4: 18.5, and to AKD of 7.4:0.5; (E) Alternatively, an HPMC solution may be contacted with glyoxal, glycerol, sorbitol, chitosan, calcium chloride, and AKD, with the following ratios: HPMC to water of 4:62, to glyoxal of 4:1.6, to glycerol of 4:1, to sorbitol of 4:18, to chitosan of 4:1, to calcium chloride of 4:5, and to AKD of 4:0.75.

[0080] A coated paper sheet may be prepared by applying the above-described coating composition to a paper substrate.

[0081] In some embodiments, the hydrophobic agent further comprises castor oil. In other embodiments, it comprises sodium silicate (40%).

[0082] In certain formulations, the coating composition may comprise about 0.1 wt% to 10 wt% CMC, about 0.1 wt% to 13 wt% sorbitol, about 0.1 wt% to 6 wt% AKD, about 0.1 wt% to 4 wt% glycerol, about 0.1 wt% to 10 wt% castor oil, and about 0.1 wt% to 35 wt% sodium silicate (40%) in water. Insuch formulations, the balance of the composition may be water, such that the total weight percent of all ingredients is 100 wt%.

[0083] In another embodiment, the composition is applied to a paper substrate at a dry coat weight of less than 10 g / m2. The resulting coating exhibits oil resistance on coated paper for at least 15 days.

[0084] In another embodiment, the coating composition melts under heat and, upon cooling and drying, forms a seal or weld between either (a) two coated substrates or (b) a coated substrate and an uncoated substrate.

[0085] In some embodiments, the aqueous barrier coating composition includes the following components by weight percent of the total composition: modified cellulose component: about 7.5 wt%, which can be carboxymethyl cellulose (CMC); plasticizer component: about 9.0 wt%, which can be sorbitol; additional plasticizer: about 1.5 wt%, which can be glycerol; hydrophobic agent component: about 3.6 wt%, which can be alkyl ketene dimer (AKD); additional hydrophobic component: about 7.5 wt%, which can be castor oil; crosslinking / support component: about 20 wt% to 25 wt%, which can be sodium silicate (40% aqueous solution); balance: about 55.9 wt% water.

[0086] The components may be mixed in water at 60-80°C under continuous stirring to form a stable emulsion or solution. After mixing, the coating composition may be applied to paper or pulp-based substrates using a blade coater, rod coater, or other standard techniques. The coated substrate is then dried at ambient temperature or using controlled drying ovens to achieve a dry coat weight of 6-10 gsm.

[0087] The castor oil contributes additional lipid repellency while the sodium silicate enhances film formation and crosslinking. The blend of plasticizers allows for improved flexibility and adhesion to cellulose substrates. Ongoing formulations aim to further increase hydrophobicity without compromising biodegradability or compostability.

[0088] In some embodiments, the aqueous cellulose-based barrier coating composition comprises the following components in the listed weight percent (wt%) based on the total weight of the composition:

[0089] Carboxymethyl cellulose (CMC):From about 0.1 wt% to about 10 wt%, comprising approximately or about 0.2 wt%, 0.25 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1.0 wt%, 1.2 wt%, 1.5 wt%, 1.8 wt%, 2.0 wt%, 2.5 wt%, 3.0 wt%, 3.5 wt%, 4.0 wt%, 4.5 wt%, 5.0 wt%, 6.0 wt%, 7.0 wt%, 7.5 wt%, 8.0 wt%, 9.0 wt%, and 10.0 wt%. The CMC content may fall within one or more of the following subranges: 0.1-1.0 wt%, 0.5-2.5 wt%, 1.0-5.0 wt%, 2.0-7.5 wt%, 5.0-10.0 wt%, or 7.5-10.0 wt%, depending on the intended viscosity, film formation requirements, barrier properties, and interaction with plasticizers and hydrophobic agents.

[0090] Sorbitol:From about 0.1 wt% to about 13 wt%, comprising approximately or about 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1.0 wt%, 1.2 wt%, 1.5 wt%, 2.0 wt%, 2.5 wt%, 3.0 wt%, 4.0 wt%, 5.0 wt%, 6.0 wt%, 7.0 wt%, 8.0 wt%, 9.0 wt%, 10.0 wt%, 11.0 wt%, 12.0 wt%, and 13.0 wt%.

[0091] Alkyl ketene dimer (AKD):From about 0.1 wt% to about 6 wt%, comprising approximately or about 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1.0 wt%, 1.2 wt%, 1.5 wt%, 2.0 wt%, 2.5 wt%, 3.0 wt%, 3.2 wt%, 3.5 wt%, 3.6 wt%, 4.0 wt%, 5.0 wt%, and 6.0 wt%.

[0092] Glycerol:From about 0.1 wt% to about 4 wt%, comprising approximately or about 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1.0 wt%, 1.2 wt%, 1.4 wt%, 1.5 wt%, 1.6 wt%, 1.8 wt%, 2.0 wt%, 2.5 wt%, 3.0 wt%, 3.5 wt%, and 4.0 wt%. The glycerol content may fall within one or more of the following sub-ranges: 0.1-1.0 wt%, 0.5-2.0 wt%, 1.0-2.5 wt%, 2.0-3.0 wt%, or 3.0-4.0 wt%, about 0.1 wt% to 4 wt%

[0093] Castor oil:

[0094] In some embodiments, the hydrophobic agent further comprises castor oil. The amount of castor oil in the coating composition may range from 0.1 wt% to 10 wt%. In various embodiments, theamount may be 0.1 wt%, 0.25 wt%, 0.5 wt%, 0.75 wt%, 1.0 wt%, 1.25 wt%, 1.5 wt%, 1.75 wt%, 2.0 wt%, 2.25 wt%, 2.5 wt%, 2.75 wt%, 3.0 wt%, 3.25 wt%, 3.5 wt%, 3.75 wt%, 4.0 wt%, 4.25 wt%, 4.5 wt%, 4.75 wt%, 5.0 wt%, 5.25 wt%, 5.5 wt%, 5.75 wt%, 6.0 wt%, 6.25 wt%, 6.5 wt%, 6.75 wt%, 7.0 wt%, 7.25 wt%, 7.5 wt%, 7.75 wt%, 8.0 wt%, 8.25 wt%, 8.5 wt%, 8.75 wt%, 9.0 wt%, 9.25 wt%, 9.5 wt%, 9.75 wt%, or 10.0 wt%. The castor oil content may fall within one or more of the following subranges: 0.1-1.0 wt%, 0.5-2.5 wt%, 1.0-3.0 wt%, 2.0-4.0 wt%, 3.0-6.0 wt%, 5.0-7.5 wt%, or 7.0- 10.0 wt%, depending on the desired balance of flexibility, hydrophobicity, and oil resistance.Sodium silicate (40% aqueous solution):

[0095] The amount of sodium silicate (40%) in the coating composition may range from 0.1 wt% to 35 wt%. In various embodiments, the amount may be 0.1 wt%, 0.25 wt%, 0.5 wt%, 0.75 wt%, 1.0 wt%, 1.25 wt%, 1.5 wt%, 1.75 wt%, 2.0 wt%, 2.25 wt%, 2.5 wt%, 2.75 wt%, 3.0 wt%, 3.25 wt%, 3.5 wt%, 3.75 wt%, 4.0 wt%, 4.25 wt%, 4.5 wt%, 4.75 wt%, 5.0 wt%, 6.0 wt%, 7.0 wt%, 8.0 wt%, 9.0 wt%, 10.0 wt%, 12.5 wt%, 15.0 wt%, 17.5 wt%, 20.0 wt%, 22.5 wt%, 25.0 wt%, 27.5 wt%, 30.0 wt%, 32.5 wt%, or 35.0 wt%. The sodium silicate content may fall within one or more of the following subranges: 0.1-1.0 wt%, 0.5-5.0 wt%, 1.0-10.0 wt%, 5.0-15.0 wt%, 10.0-20.0 wt%, 15.0-25.0 wt%, 20.0-30.0 wt%, or 25.0-35.0 wt%, depending on the desired level of barrier performance, crosslinking contribution, and film formation characteristics.

[0096] In a representative embodiment, the coating composition comprises approximately 7.5 wt% CMC, 9.0 wt% sorbitol, 3.6 wt% AKD, 1.5 wt% glycerol, 7.5% castor oil, and 20.0 wt% sodium silicate (40%), with the remainder being water.

[0097] EXAMPLE 4: MOISTURE VAPOR TRANSMISSION RATE (MVTR) TESTING

[0098] Moisture vapor transmission rate testing was performed using coated paper specimens prepared according to Coating C. Circular specimens (6.5 cm diameter) were sealed onto vapometer cups, and weight changes were recorded over 72 hours. MVTR values were calculated and normalized tog / m2 / day. The test was performed at 23 degrees Celsius and 50% relative humidity. Results are summarized in Table 4 below.

[0099] Table 4. MVTR results for Coating C under varied coat weightsGSM (g / m2) Thickness (mm) Time (hr) MVTR (g / m2 / day)18.2 0.1538 24 12.0848 15.1072 10.0719.1 0.1574 24 6.0448 3.0272 7.0422.0 0.1456 24 12.0048 15.1072 10.07

Claims

CLAIMSWhat is claimed is:

1. An aqueous cellulose-based barrier coating composition comprising modified cellulose component, water, plasticizer component, crosslinking agent component, and hydrophobic agent component; wherein the aqueous cellulose-based coating composition has a weight ratio of water to modified cellulose of from about 2: 1 to about 999:1; wherein the plasticizer component is present in the aqueous cellulose-based coating composition in a weight ratio of plasticizer to modified cellulose of from about 1 : 1 ,000 to about 1 : 1; wherein the crosslinking agent is present in the aqueous cellulose- based coating composition in a weight ratio of crosslinking agent to modified cellulose of from about 1:1,000 to about 1 :2; wherein the hydrophobic agent component is present in the aqueous cellulose-based coating composition in a weight ratio of hydrophobic agent to modified cellulose of from about 1:1,000 to about 1 :1; wherein the modified cellulose component comprises carboxymethylcellulose (CMC) and / or alkaline metal salt of carboxymethylcellulose and / or hydroxy propyl methyl cellulose (HPMC); wherein the plasticizer component comprises glycerol, sorbitol, xylitol, and / or mannitol; wherein the crosslinking agent component comprises glyoxal, N- hydroxymethyl acrylamide, GPAM, and / or PAE; wherein the hydrophobic agent component comprises alkyl ketene dimers (AKDs), PDMS, silicon dioxide, calcium chloride, trichloro(octadecyl) silane (TOS), ethyl 2-cyanoacrylate, chitosan, and / or wax.

2. The aqueous cellulose-based barrier coating composition of claim 1, wherein the aqueous cellulosic-based coating is an aqueous solution.

3. The aqueous cellulose-based barrier coating of any preceding claim, wherein the aqueous cellulose-based barrier coating composition comprises the modified cellulose component in an amount of from about 0.1 wt.% to about 50 wt.% based on the total weight of the composition.

4. The aqueous cellulose-based barrier coating of any preceding claim, wherein the aqueous cellulose-based barrier coating comprises the plasticizer component in an amount of from about 0.1 wt.% to about 50 wt.% based on the total weight of the composition.

5. The aqueous cellulose-based barrier coating of any preceding claim, wherein the aqueous cellulose-based barrier coating comprises the crosslinking agent component in an amount of from about 0.1 wt.% to about 25 wt.% based on the total weight of the composition.

6. The aqueous cellulose-based barrier coating of any preceding claim, wherein the aqueous cellulose-based barrier coating comprises the hydrophobic agent component in an amount of from about 0.1 wt.% to about 40 wt.% based on the total weight of the composition.

7. The aqueous cellulose-based barrier coating of any preceding claim, wherein the aqueous cellulose-based barrier coating composition is prepared by a formulation method comprising mixing carboxymethyl cellulose, hydroxy propyl methyl cellulose, glycerol, sorbitol, glyoxal, and alkyl ketene dimers at a temperature of from about 1°C to about 300°C.

8. The aqueous cellulose-based barrier coating of any preceding claim, wherein the aqueous cellulose-based barrier coating composition is prepared by a formulationmethod comprising mixing carboxymethyl cellulose, hydroxy propyl methyl cellulose, glycerol, sorbitol, glyoxal and alkyl ketene dimers for about 0.01 minutes to about 1,000 minutes.

9. The aqueous cellulose-based barrier coating of any preceding claim, wherein the aqueous cellulose-based coating is characterized by a degree of biodegradability of equal to or greater than about 95%, and wherein the degree of biodegradability refers to aerobic biodegradability in soil as determined in accordance with ISO 17556:2003 E.

10. The aqueous cellulose-based barrier coating of any preceding claim, wherein the aqueous cellulose-based coating has a dried or cured weight of 5-30 glnv.

11. The aqueous cellulose-based barrier coating of claim 10, wherein the aqueous cellulose-based barrier coating seals or welds to itself once dried when pressure is applied at 100 PSI, 200 degrees C for 0.7 seconds or less.

12. A product coated with the aqueous cellulose-based barrier coating of claims 1-11, wherein the product is a cup, bowl, plate, straw, agricultural film, corrugated box, paper mailer, or flexible material.

13. A method of making an aqueous cellulose-based coating composition, the method comprising: contacting modified cellulose (CMC and / or CMC-Na) with water to form a modified cellulose (CMC and / or CMC-Na) solution (I);(A) contacting at least a portion of the modified cellulose solution (I) with a glyoxal, glycerol, hydroxy propyl methyl Cellulose (HPMC), and alkyl ketene dimers ( AKD); and wherein the aqueous cellulose-based coating composition is characterized by a weight solid ratio of modified cellulose (CMC and / or CMC-Na) to water of about 6.5: 78.9, modifiedcellulose (CMC and / or CMC-Na) to glyoxal of about 6.5: 3, a modified cellulose (CMC and / or CMC-Na) to glycerol of about 6.5:0.5, modified cellulose (CMC and / or CMC-Na) to hydroxy propyl methyl cellulose (HPMC) of about 6.5:3.2, and modified cellulose (CMC and / or CMC-Na) to alkyl ketene dimers (AKD) of about 6.5: 0.75;(B) contacting at least a portion of the modified cellulose solution (I) with a glyoxal, glycerol, hydroxy propyl methyl cellulose (HPMC), sorbital, and alkyl ketene dimers (AKD); and wherein the aqueous cellulosic-based coating is characterized by a weight solid ratio of modified cellulose (CMC and / or CMC-Na) to water of about 3.2: 64.5, modified cellulose (CMC and / or CMC-Na) to glyoxal of about 3.2: 1.4, modified cellulose (CMC and / or CMC-Na) to glycerol about of about 3.2:0.5, modified cellulose (CMC and / or CMC- Na) to hydroxy propyl methyl cellulose (HPMC) of about 3.2: 1.6, modified cellulose (CMC and / or CMC-Na) to sorbitol of about 3.2: 23, and modified cellulose (CMC and / or CMC- Na) to alkyl ketene dimers (AKD) of about 3.2: 0.4;(C) contacting at least a portion of the modified cellulose solution (I) with a glyoxal, glycerol, sorbitol, and alkyl ketene dimers (AKD); and wherein the aqueous cellulosic-based coating is characterized by a weight solid ratio of modified cellulose (CMC and / or CMC- Na) to water of about 7.4: 65.2, modified cellulose (CMC and / or CMC-Na) to glyoxal of about 7.4: 1.8, modified cellulose (CMC and / or CMC-Na) to glycerol of about 7.4: 0.7, modified cellulose (CMC and / or CMC-Na) to sorbitol of about 7.4: 18.5, and modified cellulose (CMC and / or CMC-Na) to alkyl ketene dimers (AKDs) of about 7.4: 0.5 and / or(D) dissolving HPMC in water and then contacting at least a portion of the HPMC solution with a glyoxal, glycerol, sorbitol, chitosan , calcium chloride and alkyl ketene dimers(AKDs); and wherein the aqueous cellulosic-based coating is characterized by a weight solidratio of HPMC (hydroxy propyl methyl cellulose) to water of about 4: 62 HPMC (hydroxy propyl methyl cellulose) to glyoxal of about 4: 1.6, HPMC (hydroxy propyl methyl cellulose) to glycerol of about 4: 1, HPMC (hydroxy propyl methyl cellulose) to sorbitol of about 4: 18, HPMC (hydroxy propyl methyl cellulose) to chitosan of about 4:1, HPMC (hydroxy propyl methyl cellulose): calcium chloride 4:5, and HPMC (hydroxy propyl methyl cellulose) to alkyl ketene dimers (AKDx) of about 4: 0.75.

14. A method of making a coated paper sheet with a modified cellulosed-based coating composition, the method comprising applying a paper substrate with a composition prepared by the method of claim 11.

15. The aqueous cellulose-based barrier coating composition of any preceding claim, wherein the hydrophobic agent further comprises castor oil.

16. The aqueous cellulose-based barrier coating composition of any preceding claim, wherein the hydrophobic agent further comprises sodium silicate (40%).

17. The aqueous cellulose-based barrier coating composition of any preceding claim, wherein the composition comprises about 0.1 wt% to 10 wt%, CMC, about 0.1 wt% to 13 wt% sorbitol, about 0.1 wt% to 6 wt% AKD, about 0.1 wt% to 4 wt% glycerol, about 0.1 wt % to 10 wt% castor oil, and about 0.1 wt% to 35 wt% sodium silicate (40%) in water.

18. The aqueous cellulose-based barrier coating composition of any preceding claim, wherein the balance of the composition is water, such that the total composition comprises 100 wt%.

19. The aqueous cellulose-based barrier coating composition of claims 15-18, wherein the composition is applied to a paper substrate at a dry coat weight of less than 10 gsm.

20. The aqueous cellulose-based barrier coating composition of claims 17-19, wherein the coating exhibits oil resistance on coated paper for at least 24 hours when 6 gsm coating is applied to the substrate.

21. A product of claim 11, wherein the aqueous cellulose-based barrier coating melts under heat and, upon cooling and drying, forms a seal or weld between:(a) two coated substrates; or(b) a coated substrate and an uncoated substrate

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