Biowax emulsion as a bio-based barrier coating dispersion

Abstract

The present invention relates to compositions and methods for forming substantially bio-based barrier coatings on paper and cardboard substrates. The bio-based barrier coating of the present invention comprises a biowax emulsion containing one or more biowaxes, such as castor oil wax, formed by the hydrogenation of a bio-based oil, such as castor oil. The barrier coating composition is formed by dispersing the biowax emulsion in a polyacrylate carrier dispersion and can be applied as a coating on, for example, paper or cardboard, such as that made of recycled fibers, using conventional industrial methods at ambient temperature.

Description

[Technical Field]

[0001] Related applications This application claims priority to U.S. Provisional Application No. 63 / 456,167 filed on 31 March 2024 and Finnish Application No. 20235948 filed on 28 August 2023, the contents of both applications being incorporated in their entirety by reference.

[0002] The present invention relates to compositions and methods for forming substantially bio-based barrier coatings, for example, on paper and cardboard substrates. Specifically, the disclosure provides biowax-based barrier compositions that can form a barrier layer to enhance oil resistance, grease resistance, and water resistance, and can be applied without causing damage to the substrate. [Background technology]

[0003] Various coatings can be applied to the surface of paper or cardboard to improve their properties. Oil, grease, water, and water vapor barrier properties are particularly important for paper and cardboard used for packaging products. Coatings applied to the surface of paper or cardboard must provide an effective barrier against leakage from the goods inside the packaging material and / or protect the packaged goods from contamination and / or contact with the surrounding outside air. Barrier requirements are particularly stringent for packaging materials used for food products and consumable liquids.

[0004] The barrier resistance and wettability of paper or cardboard are generally controlled by applying petroleum-based derivatives and polymers as coatings, such as polyacrylates, polyethylene, ethylene vinyl alcohol (EVOH), polyvinylidene chloride (PVDC), petroleum waxes, and / or fluorocarbon derivatives. Coatings of petroleum-based polymer emulsions are used in food or beverage packaging, such as food packaging materials made from paper, plates, bowls, cups, and containers. Barrier coatings based on petroleum or synthetic polymers dominate the current market due to their low cost and readily available availability. Such coatings can be applied using conventional printing or coating techniques.

[0005] While the use of petroleum-based polymers improves surface hydrophobicity, water resistance, and oil / grease resistance (OGR), petroleum-based polymers are becoming less favored due to environmental concerns regarding the limited availability of petroleum resources, insufficient recyclability, and the lack of biodegradability of the resulting waste. Since food and beverage packaging is often used only once, for environmental reasons, it is desirable that packaging coating compositions be made from sustainably sourced, renewable, and bio-based materials. Additionally, consumer demand for sustainable and renewable bio-based paperboard barrier coating products has increased dramatically in recent years. Generally, coating dispersions with a bio-content exceeding 50% by weight can be certified and labeled as bio-based products in the market.

[0006] These factors are driving interest in alternative biopolymer films and coatings that possess similar properties to petroleum-based coatings. Paper coating manufacturers are increasingly replacing fossil-based chemicals with bio-based materials in their current barrier coating polymer emulsions.

[0007] As an alternative to petroleum-based derivatives, novel compositions can be formulated to substantially form bio-based barrier coatings for paper and cardboard using biopolymers containing polysaccharides, proteins, and polyesters, as well as bio-based waxes (i.e., biowaxes) containing hydrogenated bio-based oils and biolipids. These bio-based materials as barrier coatings for paper coatings have the potential to replace current petroleum-based barrier coating materials. However, difficulties in processing most biopolymers can arise from hydrophilicity, crystallization behavior, high viscosity, undesirable rheology, brittleness, and / or melt instability, which hinder their full utilization on an industrial scale.

[0008] Biowaxes containing hydrogenated bio-based oils (vegetable and animal oils) are being successfully used to produce bio-based coating materials for paper coating. Biowaxes, including barrier coatings as described herein, exhibit a remarkable increase in resistance to oil, grease, and moisture when used to directly coat paper / cardboard. However, most commercial biowax liquid formulations must be applied to the paper surface at temperatures of 80-160°C using a wax applicator or other specialized equipment. When applied at high temperatures, biowax liquids tend to (i) destroy the paper fiber strength and (ii) cause discoloration of the paper.

[0009] Currently, the market does not meet the need for a substantially bio-based barrier coating for paper and cardboard that (i) is a stable dispersion, (ii) has a high bio-based content (>50% of total coating solids), and (iii) can be applied at room temperature using a conventional paper coater or metering size press without causing damage or discoloration to paper / cardboard substrates. Developing such a stable, high-bio-content coating dispersion remains a challenge.

[0010] This application addresses this problem by providing novel compositions and methods for forming substantially bio-based barrier coatings for paper and cardboard. The present invention provides biowax-based barrier compositions that can form a barrier layer to enhance oil resistance, grease resistance, and water resistance, delivering a sustainable bio-based barrier coating solution that can be applied without causing damage to the substrate and potentially replace or minimize the need for conventional petroleum-based coatings. [Overview of the Initiative]

[0011] The present invention relates to compositions and methods for forming substantially bio-based barrier coatings for application onto, for example, paper and cardboard substrates, such as those made of recycled fibers.

[0012] A barrier coating composition is formed using a biowax emulsion, polyacrylate dispersion, and other additives, facilitating application as a barrier coating using conventional methods at room temperature, and possessing a long shelf life, high solids content, high bio-based content, and rheological properties. A barrier coating composition comprising a biowax emulsion dispersed in one or more polyacrylate carriers together with one or more rheological modifiers and auxiliary additives (e.g., clay, MCC, etc.) provides, when used to coat paper and / or cardboard, (i) a bio-content exceeding 50% in two coating layers (renewable raw materials), and (ii) <5 g / m². 2 The two-layer coated sheet achieved excellent oil and water barrier properties, including a Cobb value (30 minutes) and a KIT value of 12.

[0013] In one aspect, the present invention provides a barrier coating composition for paper or cardboard, and the barrier coating composition,

[0014] (a) One or more biowax emulsions,

[0015] (b) One or more polyacrylate carriers,

[0016] (c) optionally includes one or more auxiliary additives,

[0017] The one or more biowax emulsions

[0018] (i) Optionally, one or more biowaxes including palm oil wax, castor oil wax, soybean oil wax, fish oil wax, animal fat wax, vegetable oil wax, animal fat wax, a blend of vegetable oil wax and animal fat wax, or any combination thereof,

[0019] (ii) Optionally, one or more rosin sizing agents comprising reinforced rosin, esterified rosin, rosin wax, resin acid derivatives, gum rosin, wood rosin, tall oil rosin, rosin paste, rosin-based dispersion, or any combination thereof,

[0020] (iii) Optionally, one or more surfactants comprising one or more nonionic surfactants, one or more anionic surfactants, or a combination thereof, wherein (a) the one or more nonionic surfactants include, but are not limited to, ethoxylated alcohols such as secondary alcohol ethoxylates, ethoxylated sorbitan esters, sorbitan esters, but are not limited to glycerol monostearate (GMS), and any combination thereof, and (b) the one or more anionic surfactants include, but are not limited to, fatty alcohol ether sulfates, alkyl ether sulfates, special soaps such as anionic long-chain fatty acids, and any combination thereof,

[0021] (iv) optionally, one or more microcrystalline or paraffin waxes comprising a saturated hydrocarbon wax, a paraffinic hydrocarbon wax, an isoparaffinic hydrocarbon wax, a naphthenic hydrocarbon wax, and mixtures thereof, having a freezing point of 50 to 110 °C, 65 to 100 °C, 70 to 90 °C, or 75 to 85 °C

[0022] (v) optionally, one or more long-chain fatty acids having a carbon chain length in the range of C18 - C30, C20 - C30, C22 - C30, or C24 - C30

[0023] In some embodiments, the barrier coating composition further comprises one or more rheology modifiers.

[0024] In some exemplary embodiments, the one or more biowaxes

[0025] (a) include, but are not limited to, one or more hydrogenated bio-based oils such as palm oil, castor oil, soybean oil, fish oil, tallow oil, vegetable oil, animal oil, blends of vegetable oil and animal oil, or any combination thereof, each of the hydrogenated bio-based oils having a higher melting point compared to the corresponding non-hydrogenated bio-based oil, and

[0026] (b) having a melting point of 55 to 98 °C, 60 to 95 °C, 65 to 90 °C, 70 to 85 °C, or 75 to 80 °C.

[0027] In some exemplary embodiments according to any of the foregoing, in the one or more biowax emulsions

[0028] (a) the one or more biowaxes include castor oil wax,

[0029] (b) the one or more rosin sizing agents include fortified rosin size.

[0030] (c) The nonionic surfactant comprises a secondary alcohol ethoxylate, glycerol monostearate (GMS), or a combination thereof, and the anionic surfactant comprises an anionic long-chain fatty acid, or a combination thereof.

[0031] (d) The one or more microcrystalline or paraffinic waxes have a freezing point of 70 to 90°C,

[0032] (e) The one or more long-chain fatty acids have a carbon chain length in the range of C22 to C30.

[0033] In some exemplary embodiments described above, the one or more biowax emulsions are

[0034] (a) One or more biowaxes in an amount in the range of 20-60% by weight, 25-55% by weight, 30-50% by weight, or 35-45% by weight,

[0035] (b) One or more rosin sizing agents in an amount in the range of 1-12% by weight, 2-10% by weight, 3-8% by weight, or 4-6% by weight,

[0036] (c) One or more surfactants in an amount ranging from 2 to 12% by weight, 4 to 10% by weight, or 6 to 8% by weight,

[0037] (d) One or more of the microcrystalline or paraffinic waxes in an amount ranging from 2 to 10% by weight, 3 to 9% by weight, 4 to 8% by weight, or 5 to 7% by weight,

[0038] (e) optionally comprising one or more of the long-chain fatty acids in an amount ranging from 0.5 to 6% by weight, 1 to 5% by weight, or 2 to 4% by weight.

[0039] In some exemplary embodiments described above, the one or more biowax emulsions are

[0040] (a) Combining one or more biowaxes, one or more rosin sizing agents, one or more surfactants, one or more microcrystalline or paraffinic waxes, and optionally one or more long-chain fatty acids in a reactor, and optionally heating to 70-99°C, 75-98°C, 85-95°C, or 90-95°C to form an oil phase,

[0041] (b) Adding a certain amount of hot water to the oil phase, wherein the hot water is optionally 70-99°C, 75-98°C, 85-95°C, or 90-95°C.

[0042] (c) Emulsification at 70-99°C, 75-98°C, or 85-95°C for a time period of 0.5-5 hours, 0.5-4 hours, or 1-3 hours, as optional.

[0043] (d) Homogenization and

[0044] (e) Optionally, the obtained reversed-phase biowax emulsion is cooled to a temperature in the range of 10–35°C, 15–30°C, or 20–25°C using an ice bath, cooling jacket, or cooling core.

[0045] (f) Optionally, the addition of a biocide and the inverse phase biowax emulsion formed by the addition of the biocide.

[0046] In some exemplary embodiments described above, the one or more biowax emulsions are, in their final form,

[0047] (a) containing a total solids content in the range of 50-80% by weight, 50-70% by weight, 50-60% by weight, or 55-57% by weight, wherein ≥50% by weight of the total solids content is bio-based and / or

[0048] (b) Having a final bulk viscosity in the range of 1400-1800 cPs, 1500-1700 cPs, 1550-1650 cPs, or 1590-1610 cPs.

[0049] In some exemplary embodiments described above,

[0050] (a) The one or more polyacrylate carrier comprises an aqueous polyacrylate dispersion containing one or more polyacrylate polymers having a weight-average molecular weight of 10,000 to 1,000,000 Da, 100,000 to 800,000 Da, or 200,000 to 600,000 Da, wherein the aqueous polyacrylate dispersion has a total dry solids content in the range of 40 to 60% by weight, 45 to 55% by weight, or 49 to 51% by weight.

[0051] (b) The one or more rheological modifiers include, but are not limited to, one or more bio-based gums, such as pre-hydrated cellulose gum, xanthan gum, or mixtures thereof; one or more bio-based hydrocolloids; but are not limited to, one or more polyacrylate dispersions having a charge in the range of 70-100 mol%, 80-100 mol%, or 90-100 mol% and a molecular weight in the range of 1,000-100,000 Da, 2,000-80,000 Da, or 10,000-50,000 Da; or a combination thereof.

[0052] (c) The one or more auxiliary additives are selected from clay, kaolin, alumina, silica, nanoclay, nanocellulose, nanostructured cellulose, cellulose nanofiber (CNF), nanofibrillated cellulose (NFC), bacterial nanocellulose, cellulose nanocrystals (CNC), microfibrillated cellulose (MFC), and microcrystalline cellulose (MCC), and any combination thereof.

[0053] (d) Any combination of (a), (b), and (c).

[0054] In some exemplary embodiments described above, one or more auxiliary additives include:

[0055] (a) The clay and / or nanoclay is formulated as an aqueous slurry having a total solids content of 60-80% by weight, 65-75% by weight, or 68-72% by weight before being dispersed in the barrier coating composition.

[0056] (b) The cellulose nanocrystals (CNCs) are incorporated as an aqueous slurry or spray-dried powder before being dispersed in the barrier coating composition, and optionally produced by acid hydrolysis of cellulose.

[0057] (c) The microfibrillated cellulose (MFC) is (i) having an average particle length in the range of 20-200 μm, 50-200 μm, 100-200 μm, or 150-200 μm, (ii) having an average particle width in the range of 0.1-1 μm, 0.2-1 μm, 0.4-1 μm, or 0.6-1 μm, and (iii) being formulated as an aqueous solution having a dry content of 10-30% by weight, 15-25% by weight, or 18-22% by weight before being formulated with the barrier coating composition.

[0058] (d) The microcrystalline cellulose (MCC) (i) has an average particle size in the range of 1-8 μm, 2-7 μm, 3-6 μm, or 4-5 μm, and (ii) is incorporated as an aqueous slurry or spray-dried powder before being dispersed in the barrier coating composition.

[0059] In some exemplary embodiments described above,

[0060] (a) The one or more rheological modifiers include pre-hydrated cellulose gum and xanthan gum,

[0061] (b) The one or more auxiliary additives include clay, nanoclay, microcrystalline cellulose (MCC), or a combination thereof.

[0062] In some exemplary embodiments described above, the barrier coating composition

[0063] (a) one or more biowax emulsions in an amount ranging from 20 to 80% by weight, 30 to 70% by weight, or 40 to 60% by weight,

[0064] (b) One or more polyacrylate carriers in an amount in the range of 20-80% by weight, 30-70% by weight, or 40-60% by weight,

[0065] (c) One or more rheological modifiers in an amount ranging from 0.1 to 5% by weight, 0.1 to 4% by weight, or 0.1 to 3% by weight, wherein the dosage of the one or more rheological modifiers is modified to achieve a bulk viscosity of 150 to 800 cPs for the barrier coating composition in the final form,

[0066] (d) When used as a top coat, one or more of the auxiliary additives in amounts ranging from 0 to 10% by weight, 1 to 9% by weight, 1 to 8% by weight, 1 to 6% by weight, or 1 to 3% by weight, and when used as a base coat, in amounts ranging from 30 to 70% by weight, 40 to 60% by weight, or 45 to 55% by weight.

[0067] In some exemplary embodiments described above, the barrier coating composition comprises a stable dispersion formed by dispersing one or more biowax emulsions, one or more rheological modifiers, and one or more auxiliary additives separately or together in one or more polyacrylate carriers using mechanical mixing to form a stable dispersion, wherein the barrier coating composition in its final form is

[0068] (a) Containing a total solids content in the range of 30-70% by weight, 40-60% by weight, 45-55% by weight, or 48-52% by weight,

[0069] (b) containing a bio-based solids content in the range of 40–60% by weight, 45–60% by weight, 50–60% by weight, or 55–60% by weight of the total solids content,

[0070] (c) Having particle sizes in the range of 0.2-5 μm, 1-4 μm, 2-3 μm, or 2.5-3 μm,

[0071] (d) Having a bulk viscosity in the range of 40-800 cPs, 100-700 cPs, 150-650 cPs, or 200-400 cPs,

[0072] (e) The barrier coating composition is determined to have stability for more than 3 months at 25°C, and the stability is determined to be within ±50%, ±40%, ±30%, or ±20% of the bulk viscosity in (d),

[0073] (f) Any combination of one, two, three, four, or all five of (a) to (e).

[0074] In some exemplary embodiments of any of the foregoing, a barrier coating composition is applied as one or more coatings to a lignocellulose substrate, including, but not limited to, paper, cardboard, cup stock base sheets, bleached sulfate cup stock base sheets, fast food wrappers, or 100% recycled liner board sheets, wherein the one or more coatings are formed at room temperature using a conventional paper coater, roll coater, or metering size press, and subsequently oven-cured for 60-120 seconds, 70-110 seconds, 80-100 seconds, or 90-95 seconds at 100-120°C, 105-115°C, or 108-112°C, and the following:

[0075] (a) The barrier coating composition forms a single coat layer, a base coat layer, a top coat layer, a double coating comprising a base coat layer and a top coat layer containing the same barrier coating composition, a double coating comprising a base coat layer and a top coat layer containing different barrier coating compositions, or multiple coating layers.

[0076] (b) The one or more coatings provide increased paper fiber strength and reduced paper fiber discoloration compared to biowax coatings applied at temperatures of 60-180°C, 70-170°C, or 80-160°C,

[0077] (c) The one or more coatings provide a barrier against the permeation of one or more oils, greases, or water into or through the lignocellulosic substrate at temperatures in the range of 5 to 95°C, 15 to 90°C, 25 to 85°C, or 40 to 60°C, wherein the barrier against permeation is one or more coatings formed in the same manner from the polyacrylate carrier alone.

[0078] (d) When one or more coatings are applied at a coat weight of 10–30, 16–22, or 18–20 grams (gsm) per square meter, they result in equal or enhanced KIT test values ​​(i.e., measures of oil and grease resistance) and Cobb 30-minute test values ​​(i.e., measures of the mass of water absorbed per square meter over 30 minutes) (i.e., higher KIT values ​​and lower Cobb values) compared to coatings similarly formed from the polyacrylate carrier alone.

[0079] (e) When one or more coatings are applied at a coat weight of 10-30, 16-22, or 18-20 grams (gsm) per square meter, the Cobb 30-minute test results show a decrease dependent on the coat weight,

[0080] (f) A barrier coating composition in which one or more coatings, in their final form, contain one or more of the following percentages of bio-based material: ≥50% by weight, 50-65% by weight, 50-60% by weight, or 50-55% by weight.

[0081] In another aspect, the present invention provides a method for preparing a barrier coating composition for paper or cardboard, optionally comprising any of the compositions described above, wherein the method is

[0082] (a) Forming at least one biowax emulsion,

[0083] (b) Forming or providing one or more polyacrylate carriers,

[0084] (c) Dispersing the at least one biowax emulsion in the one or more polyacrylate carriers,

[0085] (d) Optionally, disperse one or more rheological modifiers in the one or more polyacrylate carriers,

[0086] (e) optionally dispersing one or more auxiliary additives in the one or more polyacrylate carriers,

[0087] Steps (c) to (e) are carried out together or separately.

[0088] In some exemplary embodiments of this method, the at least one biowax emulsion is

[0089] (a) One or more biowaxes selected from the group consisting of palm oil wax, castor oil wax, soybean oil wax, fish oil wax, tallow oil wax, vegetable oil wax, animal oil wax, blends of vegetable oil wax and animal oil wax, or any combination thereof, wherein the one or more biowaxes (i) comprise one or more hydrogenated bio-based oils, each of which has a higher melting point than the corresponding unhydrogenated bio-based oil, and (ii) has a melting point of 55-98°C, 60-95°C, 65-90°C, 70-85°C, or 75-80°C,

[0090] (b) One or more rosin sizing agents, including but not limited to reinforced rosin, esterified rosin, rosin wax, resin acid derivatives, gum rosin, wood rosin, tall oil rosin, rosin paste, rosin-based dispersions, or any combination thereof,

[0091] (c) One or more surfactants comprising a nonionic surfactant, anionic surfactant, or a combination thereof, wherein (i) the nonionic surfactant is selected from ethoxylated alcohols (not limited to secondary alcohol ethoxylates), ethoxylated sorbitan esters, sorbitan esters, glycerol esters (not limited to glycerol monostearate (GMS)), and any combination thereof, and (ii) the anionic surfactant is selected from one or more surfactants comprising fatty alcohol ether sulfates, alkyl ether sulfates, special soaps (not limited to anionic long-chain fatty acids), and any combination thereof,

[0092] (d) One or more microcrystalline or paraffinic waxes having a freezing point of 50-110°C, 65-100°C, 70-90°C, or 75-85°C, including but not limited to saturated hydrocarbon waxes, paraffinic hydrocarbon waxes, isoparaffinic hydrocarbon waxes, naphthenic hydrocarbon waxes, and mixtures thereof,

[0093] (e) optionally comprising one or more long-chain fatty acids having carbon chain lengths in the range of C18-C30, C20-C30, C22-C30, or C24-C30.

[0094] In some exemplary embodiments of this method, the at least one biowax emulsion is

[0095] (a) One or more biowaxes in an amount in the range of 20-60% by weight, 25-55% by weight, 30-50% by weight, or 35-45% by weight,

[0096] (b) One or more rosin sizing agents in an amount in the range of 1-12% by weight, 2-10% by weight, 3-8% by weight, or 4-6% by weight,

[0097] (c) One or more surfactants in an amount ranging from 2 to 12% by weight, 4 to 10% by weight, or 6 to 8% by weight,

[0098] (d) One or more of the microcrystalline or paraffinic waxes in an amount ranging from 2 to 10% by weight, 3 to 9% by weight, 4 to 8% by weight, or 5 to 7% by weight,

[0099] (e) optionally comprising one or more of the long-chain fatty acids in an amount ranging from 0.5 to 6% by weight, 1 to 5% by weight, or 2 to 4% by weight,

[0100] The at least one biowax emulsion is

[0101] (i) Combining one or more biowaxes, one or more rosin sizing agents, one or more surfactants, one or more microcrystalline or paraffinic waxes, and optionally one or more long-chain fatty acids in a reactor, and optionally heating to 70-99°C, 75-98°C, 85-95°C, or 90-95°C to form an oil phase,

[0102] (ii) Adding a certain amount of hot water to the oil phase, wherein the hot water is optionally 70-99°C, 75-98°C, 85-95°C, or 90-95°C.

[0103] (iii) Emulsify at 70-99°C, 75-98°C, or 85-95°C for a time period of 0.5-5 hours, 0.5-4 hours, or 1-3 hours, as optional.

[0104] (iv) Homogenization and

[0105] (v) Optionally, the obtained reversed-phase biowax emulsion is cooled to a temperature in the range of 10-35°C, 15-30°C, or 20-25°C using an ice bath, cooling jacket, or cooling core.

[0106] (vi) Optionally, the addition of a biocide and comprising a reversed-phase biowax emulsion formed by the above.

[0107] In some exemplary embodiments of this method, the at least one biowax emulsion is, in its final form,

[0108] (a) Contains a total solids content in the range of 50-80% by weight, 50-70% by weight, 50-60% by weight, or 55-57% by weight, and furthermore, ≥50% by weight of said total solids content is bio-based,

[0109] (b) Having a final bulk viscosity in the range of 1400-1800 cPs, 1500-1700 cPs, 1550-1650 cPs, or 1590-1610 cPs.

[0110] In some exemplary embodiments of this method,

[0111] (a) The one or more polyacrylate carrier comprises an aqueous polyacrylate dispersion containing one or more polyacrylate polymers having a weight-average molecular weight of 10,000 to 1,000,000 Da, 100,000 to 800,000 Da, or 200,000 to 600,000 Da, wherein the aqueous polyacrylate dispersion has a total dry solids content in the range of 40 to 60% by weight, 45 to 55% by weight, or 49 to 51% by weight.

[0112] (b) The one or more rheological modifiers include, but are not limited to, one or more bio-based gums, such as pre-hydrated cellulose gum, xanthan gum, or mixtures thereof; one or more bio-based hydrocolloids; but are not limited to, one or more polyacrylate dispersions having a charge in the range of 70-100 mol%, 80-100 mol%, or 90-100 mol% and a molecular weight in the range of 1,000-100,000 Da, 2,000-80,000 Da, or 10,000-50,000 Da; or a combination thereof.

[0113] (c) The one or more auxiliary additives are selected from clay, kaolin, alumina, silica, nanoclay, nanocellulose, nanostructured cellulose, cellulose nanofiber (CNF), nanofibrillated cellulose (NFC), bacterial nanocellulose, cellulose nanocrystals (CNC), microfibrillated cellulose (MFC), and microcrystalline cellulose (MCC), and any combination thereof.

[0114] Moreover,

[0115] (i) The clay and / or nanoclay is formulated as an aqueous slurry having a total solids content of 60-80% by weight, 65-75% by weight, or 68-72% by weight before being dispersed in the barrier coating composition using a mechanical mixing device,

[0116] (ii) The cellulose nanocrystals (CNCs) are formulated as an aqueous slurry or spray-dried powder before being dispersed in the barrier coating composition using a mechanical mixing device, and optionally produced by acid hydrolysis of cellulose.

[0117] (iii) The microfibrillated cellulose (MFC) is (i) having an average particle length in the range of 20-200 μm, 50-200 μm, 100-200 μm, or 150-200 μm, (ii) having an average particle width in the range of 0.1-1 μm, 0.2-1 μm, 0.4-1 μm, or 0.6-1 μm, and (iii) being formulated as an aqueous solution having a dry content of 10-30% by weight, 15-25% by weight, or 18-22% by weight before being formulated with the barrier coating composition.

[0118] (iv) The microcrystalline cellulose (MCC) is (i) having an average particle size in the range of 1-8 μm, 2-7 μm, 3-6 μm, or 4-5 μm, and (ii) is formulated as an aqueous slurry or spray-dried powder before being dispersed in the barrier coating composition using a mechanical mixing device.

[0119] In some exemplary embodiments of this method, the barrier coating composition is

[0120] (a) an amount of at least one biowax emulsion in the range of 20-80% by weight, 30-70% by weight, or 40-60% by weight,

[0121] (b) One or more polyacrylate carriers in an amount in the range of 20-80% by weight, 30-70% by weight, or 40-60% by weight,

[0122] (c) One or more rheological modifiers in an amount ranging from 0.1 to 5% by weight, 0.1 to 4% by weight, or 0.1 to 3% by weight, wherein the dosage of the one or more rheological modifiers is modified to achieve a bulk viscosity of 150 to 800 cPs for the barrier coating composition in the final form,

[0123] (d) optionally, when used as a top coat, one or more of the following auxiliary additives are included in amounts ranging from 0 to 10% by weight, 1 to 9% by weight, 1 to 8% by weight, 1 to 6% by weight, or 1 to 3% by weight, and when used as a base coat, in amounts ranging from 30 to 70% by weight, 40 to 60% by weight, or 45 to 55% by weight:

[0124] The at least one biowax emulsion, the one or more rheological modifiers, and optionally the one or more auxiliary additives are dispersed separately or together in the one or more polyacrylate carriers by mechanical mixing to form the barrier coating composition, and in the final form the barrier coating composition,

[0125] (i) Contains a total solids content in the range of 30-70% by weight, 40-60% by weight, 45-55% by weight, or 48-52% by weight,

[0126] (ii) containing a bio-based solids content in the range of 40-60% by weight, 45-60% by weight, 50-60% by weight, or 55-60% by weight of the total solids content,

[0127] (iii) Having particle sizes in the range of 0.2-5 μm, 1-4 μm, 2-3 μm, or 2.5-3 μm,

[0128] (iv) Having a bulk viscosity in the range of 40-800 cPs, 100-700 cPs, 150-650 cPs, or 200-400 cPs,

[0129] (v) A barrier coating composition comprising a stable dispersion having stability for more than 3 months at 25°C, wherein the stability is determined by the barrier coating composition maintaining a 3-month aging viscosity within ±50%, ±40%, ±30%, or ±20% of the bulk viscosity in (iv), or

[0130] (vi) Any combination of one, two, three, four, or all five of (a) to (e).

[0131] In some exemplary embodiments of this method, the barrier coating composition is applied as one or more coatings to a lignocellulose substrate, including, but not limited to, paper, cardboard, cup stock base sheets, bleached sulfate cup stock base sheets, fast food wrappers, or 100% recycled liner board sheets, wherein the one or more coatings are formed at room temperature using a conventional paper coater, roll coater, or metering size press, and subsequently oven-cured for 60-120 seconds, 70-110 seconds, 80-100 seconds, or 90-95 seconds at 100-120°C, 105-115°C, or 108-112°C, and the application of the barrier coating composition is as follows:

[0132] (a) The barrier coating composition forms a single coat layer, a base coat layer, a top coat layer, a double coating comprising a base coat layer and a top coat layer containing the same barrier coating composition, a double coating comprising a base coat layer and a top coat layer containing different barrier coating compositions, or multiple coating layers.

[0133] (b) The one or more coatings provide increased paper fiber strength and reduced paper fiber discoloration compared to biowax coatings applied at temperatures of 60-180°C, 70-170°C, or 80-160°C,

[0134] (c) The one or more coatings provide a barrier against the permeation of one or more oils, greases, or water into or through the lignocellulosic substrate at temperatures in the range of 5 to 95°C, 15 to 90°C, 25 to 85°C, or 40 to 60°C, wherein the barrier against permeation is one or more coatings formed in the same manner from the polyacrylate carrier alone.

[0135] (d) When one or more coatings are applied at a coat weight of 10–30, 16–22, or 18–20 grams (gsm) per square meter, they result in equal or enhanced KIT test values ​​(i.e., measures of oil and grease resistance) and Cobb 30-minute test values ​​(i.e., measures of the mass of water absorbed per square meter over 30 minutes) (i.e., higher KIT values ​​and lower Cobb values) compared to coatings similarly formed from the polyacrylate carrier alone.

[0136] (e) When one or more coatings are applied at a coat weight of 10-30, 16-22, or 18-20 grams (gsm) per square meter, the Cobb 30-minute test results show a decrease dependent on the coat weight,

[0137] (f) The one or more coatings result in a final form containing one or more of the following percentages of bio-based material: ≥50% by weight, 50–65% by weight, 50–60% by weight, or 50–55% by weight.

[0138] In another embodiment, the present invention also provides a sheet product for use as food service packaging, beverage service packaging, or any packaging material suitable for transporting and / or storing materials containing oil, water, and / or grease,

[0139] (a) A substrate comprising lignocellulose fibers and having a first large parallel surface and a second large parallel surface,

[0140] (b) A coating structure comprising a barrier coating composition of any of the aforementioned compositions, applied in at least one layer to at least one of the larger surfaces of the substrate,

[0141] The sheet-like product in question is

[0142] (i) KIT test values ​​of 11-12, or 12, and / or

[0143] (ii) Provide a sheet-like product having a Cobb 30-minute value of less than 5 gsm.

[0144] The present invention also relates to a sheet product for use as food service packaging, beverage service packaging, or any packaging material suitable for transporting and / or storing materials containing oil, water, and / or grease,

[0145] (a) A substrate comprising lignocellulose fibers and having a first large parallel surface and a second large parallel surface,

[0146] (b) A coating structure comprising a barrier coating composition prepared by any one of the above methods, applied in at least one layer to at least one of the larger surfaces of the substrate,

[0147] The sheet-like product in question is

[0148] (i) KIT test values ​​of 11-12, or 12, and / or

[0149] (ii) Provide a sheet-like product having a Cobb 30-minute value of less than 5 gsm. [Brief explanation of the drawing]

[0150] The present invention will be described in more detail below with reference to the accompanying drawings, which are described in detail below.

[0151] [Figure 1] An exemplary bar graph is provided showing the Cobb 30-minute values ​​versus the coated weight in g / m²(gsm) for a barrier-coated cup stock base sheet coated with a bilayer of the barrier coating composition according to Example 2. [Modes for carrying out the invention]

[0152] Before describing the present invention, the following definitions are provided. Unless otherwise specified, all terms should be construed in a manner that is construed by those skilled in the art.

[0153] definition As used herein, the singular forms "a," "and," and "the" refer to multiple objects unless specifically indicated by the context.

[0154] The term “lignocellulosic substrates” refers to paper and / or cardboard products formed from unused or recycled plant-derived materials of any source, which may be coated, printed, and / or formed into packaging products. For example, such substrates include paper products made from pulp by methods including forming an aqueous cellulosic papermaking pulp, flowing the pulp to form sheets, and drying the sheets. The processes of forming, flowing, and drying the papermaking pulp may be carried out in any conventional manner generally known in the art. The substrates may contain polymer reinforcing agents such as wet strength and dry strength enhancers.

[0155] The terms “sheet substrate” or “sheet product” refer to a lignocellulosic substrate that can be formed into a container for use as food service packaging, beverage service packaging, or any packaging suitable for transporting and / or storing materials containing oil, water, and / or grease. Such a sheet substrate, when flat, has a “upper” planar surface and a “lower” planar surface that are parallel to each other. These “upper” and “lower” planar surfaces are also referred to as the “first parallel large surface” and the “second parallel large surface.” These surfaces may be coated with one or more layers that form the basis of a barrier coating.

[0156] The term “barrier coating” refers to a layer or multiple layers applied as a coating to paper and cardboard products, which impart barrier properties that provide resistance to the penetration of oil, water, and grease, and / or vapors, into and through the packaging, which, if not blocked, can cause undesirable leaks and stains. Barrier coatings are often applied to one or both surfaces of paper products to make such products useful for packaging food, beverages, raw materials, and other products. Barrier properties are useful, for example, when packaged food contains oil and / or grease, such as pizza or fried chicken. Such coatings also need to provide a smooth and uniform surface finish to the “substrate,” e.g., paper or cardboard material used to make the packaging material. In some cases, the barrier coating needs to have other properties, such as being adhesive, printable, or heat-sealable, for sealing the packaging. Barrier coatings can be applied as a single coating layer of any thickness, or as multiple coating layers, including double coatings, triple coatings, and so on. The first layer to be applied may be referred to as the base coat layer, and the final layer may be referred to as the top coat layer. Consecutive layers may be applied with or without drying and / or curing between layer applications.

[0157] The term "barrier coating composition" refers to any composition in liquid, emulsion, dispersion, solid, or gaseous form that is applied to the surface of a substrate to form a barrier coating. Typically, in liquid, emulsion, or dispersion form, the barrier coating composition preferably has a viscosity that facilitates application via a conventional paper coater, paper roll coater, or metering size press at room temperature.

[0158] The term "bio-based" refers to any material that is (i) directly extracted from biomass (natural materials) such as polysaccharides, proteins, and lipids, (ii) synthesized from bio-derived materials, (iii) is a biodegradable material, or (iv) originates from sustainable and / or renewable resources. Such materials include monomers, polymers, lipids, or oils that are directly produced and extracted from microorganisms and subsequently subjected to further processing techniques such as hydrogenation, hydrolysis, esterification, fermentation, or enzymatic reactions.

[0159] The term "bio-based oil" refers to any oil that is derived whole or in part from or sourced from plants or animals, including but not limited to palm oil, castor oil, soybean oil, fish oil, animal fat oil, vegetable oil, animal fat oil, blends of vegetable and animal fat oils, or any combination thereof.

[0160] The term "biowax" refers to any wax or waxy substance derived from or sourced from bio-based oils. For example, biowax may be formed by the partial or complete hydrogenation of bio-based oils or mixtures of bio-based oils to form a biowax material with a higher melting point compared to the corresponding unhydrogenated bio-based oil.

[0161] The term "biowax emulsion" refers to an immiscible liquid emulsion or mixture containing one or more biowaxes emulsified in a reverse-phase biowax emulsion and water. A biowax emulsion may also contain one or more rosin sizing agents, one or more surfactants, one or more microcrystalline or paraffinic waxes, or one or more long-chain fatty acids, or any other material suitable for formulation as a biowax-based barrier composition for paper or cardboard. The components of a biowax emulsion may be added together or separately, and emulsification may be achieved by any convenient mixing means, with or without heating.

[0162] As used herein, the term “substantially bio-based barrier composition” means that the “barrier coating composition” as defined above is substantially or primarily composed of “bio-based” materials, for example, the composition comprising at least 50, 60, 70, 80, 90, or 95% by weight of “bio-based” materials as defined above, such as “biowaxes” and “bio-based oils” as further defined above.

[0163] The term "microcrystalline wax" refers to a type of hydrocarbon wax produced by de-oiling petrolatum as part of the petroleum refining process. Compared to paraffin wax, it contains a relatively high proportion of isoparaffinic (branched) hydrocarbons and naphthenic hydrocarbons and is characterized by its fine crystalline structure. Microcrystalline waxes generally consist of hydrocarbon waxes that primarily contain saturated acyclic and cyclic hydrocarbons, or contain such structures as major parts of their molecules. Naphthenic hydrocarbons are a type of organic compound of carbon and hydrogen that contains one or more saturated cyclic (ring) structures, or contains such structures as major parts of their molecules. Other naphthenic compounds are sometimes called naphthenes, cycloparaffins, or hydrogenated benzenes.

[0164] The term "long-chain fatty acid" refers to a carboxylic acid having an aliphatic chain with more than 12 carbon atoms. Typically, the number of carbon atoms in the aliphatic chain is indicated by the number of C atoms; for example, an aliphatic chain with 14 carbon atoms is called a C14 fatty acid. Long-chain fatty acids can be single molecules or mixtures of fatty acids with varying chain lengths. They can be linear or branched, saturated or unsaturated, or a combination thereof, and may contain mixtures of acids, anhydrides, and esters.

[0165] The term "carrier" refers to a material that is dispersed or blended with a barrier coating material, such as a biowax emulsion, to prevent the coating material from penetrating into a paper or cardboard substrate. The carrier makes it possible to apply the barrier material or barrier coating composition as a barrier coating to the paper or cardboard substrate without penetrating into the pores of the paper or cardboard. The carrier also makes it possible to apply the barrier coating to one surface of a sheet of paper or cardboard substrate without leakage or leaching to the other side.

[0166] The term "polyacrylate carrier" refers to a dispersion of polyacrylate or polyacrylate copolymer containing acrylamide and / or other monomers, in which various other components of the barrier coating material are blended or dispersed.

[0167] The term "rheological modifier" refers to any substance that can alter the rheological properties of a material (e.g., resistance to deformation and flow). They are added to formulations to increase or decrease viscosity and to control the finished properties and characteristics of a liquid composition in a desired manner.

[0168] The term "rosin sizing agent" refers to one or more alkali-treated rosins used in surface-sized paper products as a dry powder or emulsion. Rosin sizing is often added to paper or cardboard in the presence of aluminum species to increase barrier properties against water, moisture, and water vapor.

[0169] The term "enhanced rosin" refers to the main component of most rosin-sizing products, produced by reacting the levopimelic acid component of rosin with maleic anhydride. Enhanced rosin sizing agents are produced by the reaction of gum rosin with fumaric acid or maleic anhydride under favorable conditions. This is the Diels-Alder adduct, which acts as a very effective sizing agent. The Diels-Alder adduct contains extra carboxyl groups and produces a superior sizing response compared to unreacted resin acids. Rosin extracted from tall oil is commonly enhanced with fumaric acid. In this case, abietic acid and some of the related compounds are converted to tricarboxylic acid species.

[0170] The term "oil and grease resistance" or "OGR" refers to the ability to prevent the wicking or flow of hydrophobic liquids onto and over the surface of paper or cardboard. For example, higher OGR is achieved by making the surface of the paper or cardboard substrate more oleophobic by adding a barrier coating.

[0171] The term "water resistance" refers to the ability to prevent the wicking or flow of aqueous liquids onto and across the surface of paper or cardboard. For example, higher water resistance is achieved by making the surface of the paper or cardboard substrate more hydrophobic by adding a barrier coating.

[0172] The terms "dispersion" or "aqueous dispersion" generally refer to a heterogeneous mixture of fluids (e.g., water) containing solid particles, where the solid particles form a phase-separated mixture in which one substance, consisting of macroscopically or microscopically dispersed insoluble or soluble particles, is suspended throughout another substance, typically a liquid. Dispersions have a dispersed phase (suspended particles) and a continuous phase (suspension medium) resulting from phase separation. Macroscopic particles typically separate and settle rapidly, while colloids typically do not settle completely or take a long time to settle into two completely separated layers.

[0173] The term "liquid polymer" refers to a combination of at least one polymer and a liquid, typically an aqueous liquid. The polymer may be a thoroughly dissolved or partially dissolved suspension, dispersion, or slurry. "Aqueous polymer mixture" or "hydrated polymer composition" refers to a combination of at least one polymer and an aqueous liquid. When a dry polymer is combined with an aqueous liquid, the polymer is initially partially hydrated at the polymer-water interface. The polymer does not dissolve instantaneously in aqueous or non-aqueous solvents. Dissolution is controlled either by disentanglement of polymer chains or by diffusion of chains through the boundary layer adjacent to the polymer-solvent interface. After thorough mixing, the polymer may become fully hydrated, at which point the wetting process is complete, and the polymer may be partially or completely dissolved, depending on the properties and composition of the polymer and solvent.

[0174] The terms “polymer” or “polymer additive” and similar terms are used in their ordinary sense as understood by those skilled in the art, and therefore, in this specification, they may refer to or describe macromolecules (or groups of such molecules) that may contain repeating units. Polymers can be formed in a variety of ways, including by polymerizing monomers and / or by chemically modifying one or more repeating units of a precursor polymer. Unless otherwise specified, polymers may include “homopolymers” that may contain substantially identical repeating units, for example, by polymerizing a particular monomer. Unless otherwise specified, polymers may also include “copolymers” that may contain two or more different repeating units, for example, by copolymerizing two or more different monomers and / or by chemically modifying one or more repeating units of a precursor polymer. Unless otherwise specified, polymers or copolymers may also include “terpolymers” that generally refer to polymers containing three or more different repeating units. Any one of the one or more polymers considered herein may be used, for example, as a flocculant in any applicable process.

[0175] As used herein, the term “reverse-phase biowax emulsion” refers to a liquid biowax composition which is first compounded into an oil continuous phase containing a discontinuous aqueous phase dispersed in an oil phase (e.g., a hydrophobic liquid), and then an aqueous solution (e.g., water) is added to it such that the biowax composition becomes substantially an aqueous continuous phase and the hydrophobic liquid phase is dispersed in a discontinuous phase. The inversion point can be characterized as the point at which the viscosity of the inverted polymer solution reaches substantially its maximum under given conditions. In practice, this can be determined, for example, by periodically measuring the viscosity of the composition over time, and the solution is considered inverted if three consecutive measurements are within a standard of measurement error. In one embodiment of the present invention, the reverse-phase biowax emulsion is formed by combining biowax, rosin siding, a surfactant, a microcrystalline or paraffinic wax, a long-chain fatty acid, and an organic base, and heating them to 90-95°C to form an oil continuous phase. A certain amount of hot water is added to this. The mixture was emulsified at 75-98°C, then homogenized and cooled to form a reverse-phase biowax emulsion having a substantially aqueous continuous phase.

[0176] As used herein, the term "polyacrylate" refers to homopolymers of acrylate monomers, copolymers of acrylate monomers and acrylamide monomers, and also includes acrylamide polymers that are partially or completely hydrolyzed after polymerization.

[0177] As used herein, the term “polyacrylate copolymer” refers to a polymer comprising an acrylate monomer and one or more comonomers. The comonomers may be anionic, cationic, or nonionic. In certain embodiments, the comonomers are hydrophilic. Acrylamide copolymers may be unmodified or chemically modified. Typical, non-limiting comonomers include acrylic acid, vinyl acetate, vinyl alcohol, and / or other unsaturated vinyl monomers. In certain embodiments, the acrylamide-containing copolymer comprises an acrylic acid comonomer.

[0178] As used herein, the terms "hydrolyzed acrylamide" or "partially hydrolyzed acrylamide" refer to an acrylamide-containing polymer that partially reacts with water to form acrylate side chains or acrylic acid side chains.

[0179] As used herein, "emulsion polymer" generally refers to a reverse emulsion (water in oil) in which polymer-containing water droplets are suspended in an oil phase, also known as a hydrophobic phase.

[0180] As used herein, “nonionic monomer” refers to a monomer that has a net charge of zero in aqueous solution. Non-limiting examples of nonionic monomers include acrylamide, N-alkylacrylamide, N,N-dialkylacrylamide, methacrylamide, N-vinylmethylacetamide or formamide, vinyl acetate, vinylpyrrolidone, alkyl methacrylate, acrylonitrile, N-vinylpyrrolidone, other acrylic (or other ethylene-based unsaturated) esters, or other water-insoluble vinyl monomers such as styrene or acrylonitrile.

[0181] As used herein, “anionic monomer” refers to a monomer that retains a negative charge in aqueous solution. Non-limiting representative anionic monomers include acrylic acid, sodium acrylate, ammonium acrylate, methacrylic acid, 2-acrylamido-2-methylpropanesulfonic acid (AMPS), vinyl sulfonic acid, styrene sulfonic acid, maleic acid, sulfopropyl acrylate or methacrylate, or other water-soluble forms thereof or other polymerizable carboxylic acids or sulfonic acids, sulfomethylated acrylamide, and alisulfonate. Examples include sulfonate, itaconic acid, acrylamide methylbutanoic acid, fumaric acid, vinylphosphonic acid, allylphosphonic acid, phosphonomethylated acrylamide, methacrylate, itaconate, 2-acrylamide 2-methylpropanesulfonate, sulfoalkyl(meth)acrylic acid, sulfonated styrene, unsaturated dicarboxylate, sulfoalkyl(meth)acrylamide, vinyl acetate, n-vinylformamide, n-vinylacetamide, n-vinylcaprolactam, n-vinylimidazole, n-vinylpyridine, n-vinylpyrrolidone, acrylamide propyltrimonium chloride, salts of the said acid, or other anionic ethylene-based unsaturated compounds.

[0182] As used herein, “microfibrillated cellulose” and “MFC” refer to a form of cellulose obtained through a fibrillation process of cellulose fibers (i.e., a polymer made from repeating units of glucose). Using mechanical shear, cellulose fibers are separated into a three-dimensional network structure of microfibrils with a large surface area. The resulting fibrils are much smaller in diameter than the original fibers and can form a network or web-like structure. MFCs can be obtained from any convenient cellulose source, including, but not limited to, parenchymal (non-wood) cellulose, beet cellulose, and wood-based cellulose, preferably from any plant or vegetable-based cellulose source.

[0183] Description of the present invention The present invention relates to compositions and methods for forming substantially bio-based barrier coatings for application onto paper and cardboard substrates, such as those made from recycled fiber materials. The inventors provide novel compositions and methods for forming substantially bio-based barrier coatings for paper and cardboard. The present invention provides biowax-based barrier compositions that can form a barrier layer to enhance oil resistance, grease resistance, and water resistance, can be applied without causing damage to the substrate, and deliver sustainable bio-based barrier coating solutions to potentially replace or minimize the need for petroleum-based coatings.

[0184] Depending on the end-use, packaging materials require sufficient barrier properties against water, water vapor, gas / air, and grease / oil, aiming to protect the material from the surrounding environment or prevent the loss of flavor, aroma, and moisture from food. Any single layer of material used in packaging can provide a barrier against water, water vapor, gas, or grease, or a combination of up to two or three properties, but it is rare for it to provide complete protection against all four properties. The application of multiple barrier layers is often necessary.

[0185] This specification describes the formation of barrier coating compositions having long shelf life, high solids content, high bio-based content, and rheological properties, which facilitate application as barrier coatings using conventional methods at room temperature, employing biowax emulsions, polyacrylate dispersions, and other additives. Barrier coating compositions comprising a biowax emulsion dispersed in one or more polyacrylate carriers together with one or more rheological modifiers and auxiliary additives (e.g., clay, MCC, etc.) are ideal for many packaging material applications when used to coat paper and / or cardboard, possessing (i) a bio-content exceeding 50% in multiple coating layers (renewable raw materials), and (ii) <5 g / m² 2The two-layer coated sheet achieved excellent oil and water barrier properties, including a Cobb value (30 min) and a KIT value of 12.

[0186] In exemplary embodiments, one or more surfactants capable of stabilizing a water-in-oil emulsion are added to the barrier coating composition. The surfactants, in particular, reduce the interfacial tension between water and water-immiscible liquids in the liquid polymer composition to facilitate the formation of a water-in-oil polymer emulsion. Exemplary surfactants include, but are not limited to, sorbitan esters, especially sorbitan monoesters having C12-C18 groups such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, and sorbitan monooleate; sorbitan esters having two or more ester groups such as sorbitan tristyarate and sorbitan trioleate; and ethoxylated fatty alcohols having one to four ethyleneoxy groups, such as polyoxyethylene(4) dodecyl ether ether, polyoxyethylene(2) hexadecyl ether, or polyoxyethylene(2) oleyl ether. Other exemplary, non-limiting surfactants include sorbitan esters, phthalates, fatty acid glycers, glycerol esters, and the ethoxylated versions thereof. Examples of such compounds include sorbitan monooleate, reaction products of oleic acid and isopropanolamide, sodium hexadecylphthalate, sodium decylphthalate, sorbitan stearate, ricinoleic acid, hydrogenated ricinoleic acid, glyceride monoesters of lauric acid, glyceride monoesters of stearic acid, glycerol diesters of oleic acid, glycerol triesters of 12-hydroxystearic acid, glycerol triesters of ricinoleic acid, and their ethoxylated versions containing 1 to 10 moles of ethylene oxide per mole of basic emulsifier. Examples of emulsifying surfactants include modified polyester surfactants, anhydride-substituted ethylene copolymers, N,N-dialkanol-substituted fatty amides, and tallow amine ethoxylates.Furthermore, one or more surfactants may include nonionic surfactants, anionic surfactants, or combinations thereof, (i) the nonionic surfactant is selected from, but not limited to, ethoxylated alcohols, ethoxylated sorbitan esters, sorbitan esters, glycerol esters, but not limited to glycerol monostearate (GMS), and any combination thereof, (ii) the anionic surfactant is selected from, but not limited to, fatty alcohol ether sulfates, alkyl ether sulfates, special soaps, but not limited to anionic long-chain fatty acids, and Hystrene 8522 (C22 FA), and any combination thereof.

[0187] In exemplary embodiments, auxiliary additives such as clay, nanoclay, and / or microcrystalline cellulose (MCC) are added to the barrier coating composition, and a base coat is applied to increase the natural material content in the barrier coating. Clay in low dose ranges also has the ability to stabilize the final barrier coating dispersion. Previous studies have demonstrated the effectiveness of nanoclay in improving barrier performance through the bending effect. Clay with a high aspect ratio (e.g., aspect ratio = 5000) provides a good barrier with a low filler level. Excellent barrier properties can also be achieved by the combined use of nanoclay and MCC in the coating formulation. Microcrystalline cellulose (MCC) is commercially used in food production as a texturizer, anti-caking agent, artificial fat, emulsifier, and filler. MCC dry powder is well compressible and has high binding ability. Auxiliary additives of MCC and nanoclay at low dose levels (total content up to 10 wt%) further increase the oil resistance of biowaxes.

[0188] Surprisingly, the addition of viscosity significantly improved the water barrier performance of the biowax coating, and it was found that MCC used in the barrier coat further increased the water barrier performance. This provides a remarkable method for improving both the bio-content and barrier properties of paper through the optimization of barrier coat formulations.

[0189] Barrier coating composition and method In one aspect, the present invention provides a barrier coating composition for paper or cardboard, wherein the barrier coating composition is

[0190] (a) one or more biowax emulsions, (b) one or more polyacrylate carriers, and (c) optionally one or more auxiliary additives.

[0191] In some embodiments, the barrier coating composition further comprises one or more rheological modifiers.

[0192] In another aspect, the present invention provides a barrier coating composition for paper or cardboard, the barrier coating composition being

[0193] (a) one or more biowax emulsions comprising at least one biowax, water, one or more rosin sizing agents, one or more surfactants, one or more microcrystalline or paraffinic waxes, and optionally one or more pre-formed reverse-phase biowax emulsions comprising one or more long-chain fatty acids, wherein the reverse-phase biowax emulsions are separately pre-formulated before being added to the barrier coating composition; (b) one or more polyacrylate carriers; and (c) optionally one or more auxiliary additives.

[0194] In another aspect, the present invention provides a barrier coating composition for paper or cardboard, the barrier coating composition comprising (a) one or more biowax emulsions, (b) one or more polyacrylate carriers, and (c) optionally one or more auxiliary additives, the one or more biowax emulsions

[0195] (i) Optionally, one or more biowaxes including palm oil wax, castor oil wax, soybean oil wax, fish oil wax, animal fat wax, vegetable oil wax, animal fat wax, a blend of vegetable oil wax and animal fat wax, or any combination thereof,

[0196] (ii) Optionally, one or more rosin sizing agents comprising reinforced rosin, esterified rosin, rosin wax, resin acid derivatives, gum rosin, wood rosin, tall oil rosin, rosin paste, rosin-based dispersion, or any combination thereof,

[0197] (iii) Optionally, one or more surfactants comprising one or more nonionic surfactants, one or more anionic surfactants, or a combination thereof, wherein (a) the one or more nonionic surfactants include, but are not limited to, ethoxylated alcohols such as secondary alcohol ethoxylates, ethoxylated sorbitan esters, sorbitan esters, but are not limited to glycerol monostearate (GMS), and any combination thereof, and (b) the one or more anionic surfactants include, but are not limited to, fatty alcohol ether sulfates, alkyl ether sulfates, special soaps such as anionic long-chain fatty acids, and any combination thereof,

[0198] (iv) Optionally, one or more microcrystalline or paraffinic waxes having a freezing point of 50-110°C, 65-100°C, 70-90°C, or 75-85°C, including saturated hydrocarbon waxes, paraffinic hydrocarbon waxes, isoparaffinic hydrocarbon waxes, naphthenic hydrocarbon waxes, and mixtures thereof,

[0199] (v) optionally comprising one or more long-chain fatty acids having carbon chain lengths in the range of C18-C30, C20-C30, C22-C30, or C24-C30.

[0200] Biowax Emulsion

[0201] In some embodiments, one or more biowax emulsions comprise at least one biowax, one or more rosin sizing agents, one or more surfactants, one or more microcrystalline or paraffinic waxes, and optionally one or more long-chain fatty acids.

[0202] In some embodiments, one or more biowax emulsions include: (a) one or more biowaxes selected from the group consisting of palm oil wax, castor oil wax, soybean oil wax, fish oil wax, tallow oil wax, vegetable oil wax, animal oil wax, blends of vegetable oil wax and animal oil wax, or any combination thereof; (b) one or more rosin sizing agents, but not limited to, reinforced rosin, esterified rosin, rosin wax, resin acid derivatives, gum rosin, wood rosin, tall oil rosin, rosin paste, rosin-based dispersions, or any combination thereof; and (c) one or more surfactants, including nonionic surfactants, anionic surfactants, or combinations thereof, wherein (i) the nonionic surfactant is, but not limited to, ethoxylated alcohols, ethoxylated sorbitan esters, sorbita (ii) one or more surfactants selected from glycerol esters, glycerol esters, including but not limited to glycerol monostearate (GMS), and any combination thereof, wherein the anionic surfactant is selected from special soaps, including fatty alcohol ether sulfates, alkyl ether sulfates, special but not limited to anionic long-chain fatty acids, and any combination thereof; (d) one or more microcrystalline or paraffinic waxes, including but not limited to saturated hydrocarbon waxes, paraffinic hydrocarbon waxes, isoparaffinic hydrocarbon waxes, naphthenic hydrocarbon waxes, and mixtures thereof, having a freezing point of 50-110°C, 65-100°C, 70-90°C, or 75-85°C; and (e) optionally one or more long-chain fatty acids having a carbon chain length in the range of C18-C30, C20-C30, C22-C30, or C24-C30.

[0203] In some embodiments, one or more biowax emulsions include a W / O emulsion (water in oil), an inverted phase emulsion (O / W, oil in water), a W / O emulsion subjected to phase inversion to form an inverted emulsion, or an inverted phase biowax emulsion.

[0204] In some embodiments, one or more biowax emulsions include a pre-formed reverse-phase biowax emulsion which is (a) a combination in a reactor of at least one biowax, one or more rosin sizing agents, one or more surfactants, one or more microcrystalline or paraffinic waxes, and optionally one or more long-chain fatty acids, and heated to a temperature in the range of 70-99°C, 75-98°C, 85-95°C, or 90-95°C to form an oil phase, and (b) a certain amount of hot water The mixture is pre-formulated by (c) adding water (for example, 70-99°C, 75-98°C, or 85-95°C) to the oil phase, (d) emulsifying at 70-99°C, 75-98°C, or 85-95°C for an optional time range of 0.5-5 hours, 0.5-4 hours, or 1-3 hours, (e) homogenizing the mixture, (f) cooling the resulting reverse-phase biowax emulsion to a temperature range of 10-35°C, 15-30°C, or 20-25°C, and (e) optionally adding a biocide.

[0205] In some embodiments, one or more biowax emulsions comprise reversed-phase biowax emulsions, which are separately pre-formulated before being added to the barrier coating composition by dispersing the reversed-phase biowax emulsions in one or more polyacrylate carriers, an optional rheological modifier, and / or an optional auxiliary additive.

[0206] In some embodiments, one or more biowax emulsions comprise a pre-formed reverse-phase biowax emulsion, which is preferably separately pre-formulated before being added to the barrier coating composition by dispersing the reverse-phase biowax emulsion on the one or more polyacrylate carriers before, during, or after the addition of an optional rheological modifier and / or optional auxiliary additive.

[0207] In some preferred embodiments, one or more biowax emulsions comprise pre-formed reverse-phase biowax emulsions, which are preferably separately pre-formulated before being added to the barrier coating composition by dispersing the reverse-phase biowax emulsions on the one or more polyacrylate carriers before the addition of any optional rheological modifiers and / or optional auxiliary additives.

[0208] In some embodiments, a pre-formed reverse-phase biowax emulsion is separately pre-compounded and contains a total solids content in the range of 50-80% by weight, 50-70% by weight, 50-60% by weight, or 55-57% by weight, wherein ≥50% by weight of the total solids content is bio-based.

[0209] In some embodiments, a pre-formed inverted-phase biowax emulsion is separately pre-formulated and then added to (i) one or more polyacrylate carriers, (ii) optionally one or more auxiliary additives, and (iii) optionally one or more rheological modifiers, thereby forming a barrier coating composition having improved solids content, improved bio-based solids content (e.g., 40-60% by weight, 45-60% by weight, 50-60% by weight, or 55-60% by weight), improved particle size, improved bulk viscosity, and / or improved stability compared to the same barrier coating composition formed without pre-formulating one or more biowaxes as an inverted-phase biowax emulsion.

[0210] In some exemplary embodiments described above, the one or more biowax emulsions are

[0211] (a) Combining one or more biowaxes, one or more rosin sizing agents, one or more surfactants, one or more microcrystalline or paraffinic waxes, and optionally one or more long-chain fatty acids in a reactor and heating to 70-99°C, 75-98°C, 85-95°C, or 90-95°C to form an oil phase; (b) Adding a certain amount of hot water (for example, water at 70-99°C, 75-98°C, or 85-95°C) to the oil phase; (c) Optionally, 0 The invention comprises a reverse-phase biowax emulsion formed by (d) emulsifying at 70-99°C, 75-98°C, or 85-95°C for a time period ranging from 0.5-5 hours, 0.5-4 hours, or 1-3 hours; (d) homogenizing the mixture; (e) optionally cooling the resulting reverse-phase biowax emulsion to a temperature ranging from 10-35°C, 15-30°C, or 20-25°C using an ice bath, cooling jacket, or cooling core; and (f) optionally adding a biocide.

[0212] In some exemplary embodiments, the one or more biowaxes are

[0213] (a) comprising one or more hydrogenated bio-based oils, including but not limited to palm oil, castor oil, soybean oil, fish oil, animal fat oil, vegetable oil, animal oil, blends of vegetable oil and animal oil, or any combination thereof, each of which has a higher melting point than the corresponding unhydrogenated bio-based oil, and (b) having a melting point of 55-98°C, 60-95°C, 65-90°C, 70-85°C, or 75-80°C.

[0214] In some exemplary embodiments described above, in the one or more biowax emulsions,

[0215] (a) the biowax comprises castor oil wax, (b) the rosin sizing agent comprises reinforced rosin sizing, (c) the nonionic surfactant comprises a secondary alcohol ethoxylate, glycerol monostearate (GMS), or a combination thereof, the anionic surfactant comprises an anionic long-chain fatty acid, or a combination thereof, (d) the microcrystalline or paraffinic wax comprises a freezing point of 70 to 90°C, and (e) the long-chain fatty acid comprises a carbon chain length in the range of C22 to C30.

[0216] In some exemplary embodiments described above, the one or more biowax emulsions are

[0217] (a) one or more biowaxes in an amount ranging from 20 to 60% by weight, 25 to 55% by weight, 30 to 50% by weight, or 35 to 45% by weight; (b) one or more rosin sizing agents in an amount ranging from 1 to 12% by weight, 2 to 10% by weight, 3 to 8% by weight, or 4 to 6% by weight; (c) one or more surfactants in an amount ranging from 2 to 12% by weight, 4 to 10% by weight, or 6 to 8% by weight; (d) one or more microcrystalline or paraffinic waxes in an amount ranging from 2 to 10% by weight, 3 to 9% by weight, 4 to 8% by weight, or 5 to 7% by weight; and (e) optionally comprising one or more long-chain fatty acids in an amount ranging from 0.5 to 6% by weight, 1 to 5% by weight, or 2 to 4% by weight.

[0218] In some exemplary embodiments described above, the one or more biowax emulsions are, in their final form,

[0219] (a) containing a total solids content in the range of 50-80% by weight, 50-70% by weight, 50-60% by weight, or 55-57% by weight, wherein ≥50% by weight of the total solids content is bio-based, and / or (b) having a final bulk viscosity in the range of 1400-1800 cPs, 1500-1700 cPs, 1550-1650 cPs, or 1590-1610 cPs.

[0220] Polyacrylate carrier

[0221] In some exemplary embodiments described above, the one or more polyacrylate carrier comprises an aqueous polyacrylate dispersion containing one or more polyacrylate polymers having a weight-average molecular weight of 10,000 to 1,000,000 Da, 100,000 to 800,000 Da, or 200,000 to 600,000 Da, wherein the aqueous polyacrylate dispersion has a total dry solids content in the range of 40 to 60% by weight, 45 to 55% by weight, or 49 to 51% by weight.

[0222] In some exemplary embodiments, the barrier coating composition comprises one or more polyacrylate carriers in an amount ranging from 20 to 80% by weight, 30 to 70% by weight, or 40 to 60% by weight.

[0223] In some exemplary embodiments, the one or more biowax emulsions, an optional rheological modifier, and an optional auxiliary additive are dispersed directly in the one or more polyacrylate carriers, either together or separately, in any order, to form a barrier coating composition.

[0224] Rheological modifier

[0225] In some exemplary embodiments of any of the foregoing, the one or more rheological modifiers include, but are not limited to, one or more bio-based gums, such as pre-hydrated cellulose gum, xanthan gum, or mixtures thereof; one or more bio-based hydrocolloids; one or more polyacrylate dispersions, but are not limited to, polyacrylate dispersions having a charge in the range of 70-100 mol%, 80-100 mol%, or 90-100 mol% and a molecular weight in the range of 1,000-100,000 Da, 2,000-80,000 Da, or 10,000-50,000 Da; or a combination thereof.

[0226] In preferred embodiments, the one or more rheological modifiers include pre-hydrated cellulose gum and xanthan gum.

[0227] In some exemplary embodiments, the barrier coating composition comprises one or more rheological modifiers in an amount ranging from 0.1 to 5% by weight, 0.1 to 4% by weight, or 0.1 to 3% by weight, and the dosage of the one or more rheological modifiers is further modified to achieve a bulk viscosity of 150 to 800 cPs for the barrier coating composition in the final form.

[0228] In some exemplary embodiments, the one or more rheological modifiers are dispersed directly in the barrier coating composition before, during, or after the addition of the biowax emulsion, polyacrylate carrier, and / or auxiliary additives. In some exemplary embodiments, the one or more rheological modifiers are dispersed separately or together with the biowax emulsion and / or auxiliary additives directly in the one or more polyacrylate carrier.

[0229] Auxiliary additives

[0230] In some exemplary embodiments described above, the one or more auxiliary additives are selected from clay, kaolin, alumina, silica, nanoclay, nanocellulose, nanostructured cellulose, cellulose nanofiber (CNF), nanofibrillated cellulose (NFC), bacterial nanocellulose, cellulose nanocrystals (CNC), microfibrillated cellulose (MFC), and microcrystalline cellulose (MCC), as well as any combination thereof.

[0231] In preferred embodiments, the one or more auxiliary additives include clay, nanoclay, microcrystalline cellulose (MCC), or a combination thereof.

[0232] In some exemplary embodiments of any of the above, one or more auxiliary additives include: (a) the clay and / or nanoclay being incorporated as an aqueous slurry having a total solids content of 60-80% by weight, 65-75% by weight, or 68-72% by weight before being dispersed in the barrier coating composition; (b) the cellulose nanocrystals (CNC) being incorporated as an aqueous slurry or spray-dried powder before being dispersed in the barrier coating composition, optionally produced by acid hydrolysis of cellulose; and (c) the microfibrillated cellulose (MFC) being (i) 20-200 μm, 50-20 (ii) having an average particle length in the range of 0 μm, 100-200 μm, or 150-200 μm, (iii) having an average particle width in the range of 0.1-1 μm, 0.2-1 μm, 0.4-1 μm, or 0.6-1 μm, (iii) being formulated as an aqueous solution having a dry content of 10-30% by weight, 15-25% by weight, or 18-22% by weight before being blended with the barrier coating composition, and (d) the microcrystalline cellulose (MCC) having an average particle diameter in the range of 1-8 μm, 2-7 μm, 3-6 μm, or 4-5 μm, and (ii) being formulated as an aqueous slurry or spray-dried powder before being dispersed in the barrier coating composition.

[0233] In some exemplary embodiments, the one or more auxiliary additives are dispersed directly in the barrier coating composition before, during, or after the addition of the biowax emulsion, polyacrylate carrier, and / or rheology modifier. In some exemplary embodiments, the one or more auxiliary additives are dispersed separately or together with the biowax emulsion and / or rheology modifier directly in the one or more polyacrylate carrier.

[0234] In some exemplary embodiments described above, the barrier coating composition

[0235] (a) one or more biowax emulsions in an amount ranging from 20 to 80% by weight, 30 to 70% by weight, or 40 to 60% by weight; (b) one or more polyacrylate carriers in an amount ranging from 20 to 80% by weight, 30 to 70% by weight, or 40 to 60% by weight; and (c) one or more rheological modifiers in an amount ranging from 0.1 to 5% by weight, 0.1 to 4% by weight, or 0.1 to 3% by weight, wherein the dosage of the one or more rheological modifiers is The final form comprises one or more rheological modifiers modified to achieve a bulk viscosity of 150-800 cPs for a barrier coating composition, and (d) one or more auxiliary additives in amounts ranging from 0-10% by weight, 1-9% by weight, 1-8% by weight, 1-6% by weight, or 1-3% by weight when used as a topcoat, and in amounts ranging from 30-70% by weight, 40-60% by weight, or 45-55% by weight when used as a basecoat.

[0236] In some exemplary embodiments described above, the barrier coating composition comprises a stable dispersion formed by dispersing one or more biowax emulsions, one or more rheological modifiers, and one or more auxiliary additives separately or together in one or more polyacrylate carriers using mechanical mixing to form a stable dispersion, wherein the barrier coating composition in its final form is

[0237] (a) Containing a total solids content in the range of 30-70% by weight, 40-60% by weight, 45-55% by weight, or 48-52% by weight; (b) Containing a bio-based solids content in the range of 40-60% by weight, 45-60% by weight, 50-60% by weight, or 55-60% by weight of the total solids content; (c) Having a particle size in the range of 0.2-5 μm, 1-4 μm, 2-3 μm, or 2.5-3 μm; (d) 40-800 cPs, 100-7 (e) having a bulk viscosity in the range of 00 cPs, 150 to 650 cPs, or 200 to 400 cPs, and having stability for more than 3 months at 25°C, the stability being determined by the barrier coating composition which maintains an aging viscosity within ±50%, ±40%, ±30%, or ±20% of the bulk viscosity in (d), and (f) any combination of one, two, three, four, or all five of (a) to (e).

[0238] Barrier coating In some exemplary embodiments of any of the foregoing, a barrier coating composition is applied as one or more coatings to a lignocellulose substrate, including, but not limited to, paper, cardboard, cup stock base sheets, bleached sulfate cup stock base sheets, fast food wrappers, or 100% recycled liner board sheets, wherein the one or more coatings are formed at room temperature using a conventional paper coater, roll coater, or metering size press, and subsequently oven-cured for 60-120 seconds, 70-110 seconds, 80-100 seconds, or 90-95 seconds at 100-120°C, 105-115°C, or 108-112°C, and the following:

[0239] (a) The barrier coating composition forms a single coat layer, a base coat layer, a top coat layer, a double coating comprising a base coat layer and a top coat layer containing the same barrier coating composition, a double coating comprising a base coat layer and a top coat layer containing different barrier coating compositions, or multiple coating layers.

[0240] (b) The one or more coatings provide increased paper fiber strength and reduced paper fiber discoloration compared to biowax coatings applied at temperatures of 60-180°C, 70-170°C, or 80-160°C,

[0241] (c) The one or more coatings provide a barrier against the permeation of one or more oils, greases, or water into or through the lignocellulosic substrate at temperatures in the range of 5 to 95°C, 15 to 90°C, 25 to 85°C, or 40 to 60°C, wherein the barrier against permeation is one or more coatings formed in the same manner from the polyacrylate carrier alone.

[0242] (d) When one or more coatings are applied at a coat weight of 10–30, 16–22, or 18–20 grams (gsm) per square meter, they result in equal or enhanced KIT test values ​​(i.e., measures of oil and grease resistance) and Cobb 30-minute test values ​​(i.e., measures of the mass of water absorbed per square meter over 30 minutes) (i.e., higher KIT values ​​and lower Cobb values) compared to coatings similarly formed from the polyacrylate carrier alone.

[0243] (e) When one or more coatings are applied at a coat weight of 10-30, 16-22, or 18-20 grams (gsm) per square meter, the Cobb 30-minute test results show a decrease dependent on the coat weight,

[0244] (f) The one or more coatings result in a final form containing one or more of the following percentages of bio-based material: ≥50% by weight, 50–65% by weight, 50–60% by weight, or 50–55% by weight.

[0245] Method for preparing a barrier coating composition In another aspect, the present invention provides a method for preparing a barrier coating composition for paper or cardboard, optionally comprising any of the compositions described above, wherein the method is

[0246] (a) Forming at least one biowax emulsion, preferably an inverted phase emulsion,

[0247] (b) Forming or providing one or more polyacrylate carriers,

[0248] (c) Dispersing the at least one biowax emulsion in the one or more polyacrylate carriers,

[0249] (d) Optionally, disperse one or more rheological modifiers in the one or more polyacrylate carriers,

[0250] (e) optionally dispersing one or more auxiliary additives in the one or more polyacrylate carriers,

[0251] Steps (c) to (e) are carried out together or separately.

[0252] In another aspect, the present invention provides a method for preparing a barrier coating composition for paper or cardboard, optionally comprising any of the compositions described above, the method comprising:

[0253] (a) Forming at least one biowax emulsion, preferably an inverted-phase biowax emulsion,

[0254] (b) Dispersing the reversed-phase biowax emulsion on one or more polyacrylate carriers,

[0255] (c) Optionally, dispersing one or more rheological modifiers in the one or more polyacrylate carriers,

[0256] (d) optionally dispersing one or more auxiliary additives in the one or more polyacrylate carriers,

[0257] Step (a) is performed before step (b), and steps (b) through (d) are performed together or separately in the order of (b), (c), then (d), or in any order of their choice.

[0258] In some exemplary embodiments of this method, the at least one biowax emulsion is

[0259] (a) One or more biowax selected from the group consisting of palm oil wax, castor oil wax, soybean oil wax, fish oil wax, tallow oil wax, vegetable oil wax, animal oil wax, blends of vegetable oil wax and animal oil wax, or any combination thereof, wherein the one or more biowax comprises (i) one or more hydrogenated bio-based oils, the hydrogenated biowax comprising, but not limited to, palm oil, castor oil, soybean oil, fish oil, tallow oil, vegetable oil, animal oil, blends of vegetable oil and animal oil, or any combination thereof. Each of the bio-based oils has a higher melting point compared to the corresponding unhydrogenated bio-based oil, and (ii) one or more biowaxes having a melting point of 55-98°C, 60-95°C, 65-90°C, 70-85°C, or 75-80°C; (b) one or more rosin sizing agents, but not limited to, reinforced rosin, esterified rosin, rosin wax, resin acid derivatives, gum rosin, wood rosin, tall oil rosin, rosin paste, rosin-based dispersions, or any combination thereof; and (c) nonionic surfactants, anionic A surfactant, or one or more surfactants comprising a combination thereof, wherein (i) the nonionic surfactant is selected from, but not limited to, ethoxylated alcohols such as secondary alcohol ethoxylates, ethoxylated sorbitan esters, sorbitan esters, but not limited to glycerol monostearate (GMS), and any combination thereof, and (ii) the anionic surfactant is a fatty alcohol ether sulfate, alkyl ether sulfate, but not limited to anionic long-chain fatty acids (d) One or more surfactants selected from special soaps, including fatty acids, and any combination thereof; (d) One or more microcrystalline or paraffinic waxes, not limited to saturated hydrocarbon waxes, paraffinic hydrocarbon waxes, isoparaffinic hydrocarbon waxes, naphthenic hydrocarbon waxes, and mixtures thereof, having a freezing point of 50-110°C, 65-100°C, 70-90°C, or 75-85°C; (e) Optionally, having a carbon chain length in the range of C18-C30, C20-C30, C22-C30, or C24-C30;It contains one or more long-chain fatty acids.

[0260] In some exemplary embodiments of this method, the at least one biowax emulsion is

[0261] (a) one or more biowaxes in an amount ranging from 20 to 60% by weight, 25 to 55% by weight, 30 to 50% by weight, or 35 to 45% by weight; (b) one or more rosin sizing agents in an amount ranging from 1 to 12% by weight, 2 to 10% by weight, 3 to 8% by weight, or 4 to 6% by weight; (c) one or more surfactants in an amount ranging from 2 to 12% by weight, 4 to 10% by weight, or 6 to 8% by weight; (d) one or more microcrystalline or paraffinic waxes in an amount ranging from 2 to 10% by weight, 3 to 9% by weight, 4 to 8% by weight, or 5 to 7% by weight; and (e) optionally comprising one or more long-chain fatty acids in an amount ranging from 0.5 to 6% by weight, 1 to 5% by weight, or 2 to 4% by weight.

[0262] In some exemplary embodiments of this method, the at least one biowax emulsion is

[0263] (i) combining one or more biowaxes, one or more rosin sizing agents, one or more surfactants, one or more microcrystalline or paraffinic waxes, and optionally one or more long-chain fatty acids in a reactor and heating to 70-99°C, 75-98°C, 85-95°C, or 90-95°C to form an oil phase; (ii) adding a certain amount of hot water (for example, water at 70-99°C, 75-98°C, or 85-95°C) to the oil phase; and (iii) optionally, 0 The invention comprises a reverse-phase biowax emulsion formed by (iv) emulsifying at 70-99°C, 75-98°C, or 85-95°C for a time period ranging from 0.5-5 hours, 0.5-4 hours, or 1-3 hours; (iv) homogenizing the mixture; (v) optionally cooling the resulting reverse-phase biowax emulsion to a temperature ranging from 10-35°C, 15-30°C, or 20-25°C using an ice bath, cooling jacket, or cooling core; and (vi) optionally adding a biocide.

[0264] In some exemplary embodiments of this method, the at least one biowax emulsion is, in its final form,

[0265] (a) containing a total solids content in the range of 50-80% by weight, 50-70% by weight, 50-60% by weight, or 55-57% by weight, wherein ≥50% by weight of the total solids content is biobased, and (b) having a final bulk viscosity in the range of 1400-1800 cPs, 1500-1700 cPs, 1550-1650 cPs, or 1590-1610 cPs.

[0266] In some exemplary embodiments of this method,

[0267] (a) The one or more polyacrylate carrier comprises an aqueous polyacrylate dispersion containing one or more polyacrylate polymers having a weight-average molecular weight of 10,000 to 1,000,000 Da, 100,000 to 800,000 Da, or 200,000 to 600,000 Da, wherein the aqueous polyacrylate dispersion has a total dry solids content in the range of 40 to 60% by weight, 45 to 55% by weight, or 49 to 51% by weight, and (b) the one or more rheological modifiers include, but are not limited to, one or more bio-based gums, one or more bio-based hydrocolloids, but are not limited to, 70 to 100 mol%, 80 to 100 (c) The one or more polyacrylate dispersions, or combinations thereof, include polyacrylate dispersions having a charge in the range of mol%, or 90-100 mol%, and a molecular weight in the range of 1,000-100,000 Da, 2,000-80,000 Da, or 10,000-50,000 Da, and the one or more auxiliary additives are selected from clay, kaolin, alumina, silica, nanoclay, nanocellulose, nanostructured cellulose, cellulose nanofiber (CNF), nanofibrillated cellulose (NFC), bacterial nanocellulose, cellulose nanocrystals (CNC), microfibrillated cellulose (MFC), and microcrystalline cellulose (MCC), and any combination thereof.

[0268] (i) The clay and / or nanoclay is formulated as an aqueous slurry having a total solids content of 60-80% by weight, 65-75% by weight, or 68-72% by weight before being dispersed in the barrier coating composition using a mechanical mixing device,

[0269] (ii) The cellulose nanocrystals (CNCs) are formulated as an aqueous slurry or spray-dried powder before being dispersed in the barrier coating composition using a mechanical mixing device, and optionally produced by acid hydrolysis of cellulose.

[0270] (iii) The microfibrillated cellulose (MFC) is (i) having an average particle length in the range of 20-200 μm, 50-200 μm, 100-200 μm, or 150-200 μm, (ii) having an average particle width in the range of 0.1-1 μm, 0.2-1 μm, 0.4-1 μm, or 0.6-1 μm, and (iii) being formulated as an aqueous solution having a dry content of 10-30% by weight, 15-25% by weight, or 18-22% by weight before being formulated with the barrier coating composition.

[0271] (iv) The microcrystalline cellulose (MCC) is (i) having an average particle size in the range of 1-8 μm, 2-7 μm, 3-6 μm, or 4-5 μm, and (ii) is formulated as an aqueous slurry or spray-dried powder before being dispersed in the barrier coating composition using a mechanical mixing device.

[0272] In some exemplary embodiments of this method, the barrier coating composition is

[0273] (a) at least one biowax emulsion in an amount in the range of 20-80% by weight, 30-70% by weight, or 40-60% by weight; (b) one or more polyacrylate carriers in an amount in the range of 20-80% by weight, 30-70% by weight, or 40-60% by weight; and (c) one or more rheological modifiers in an amount in the range of 0.1-5% by weight, 0.1-4% by weight, or 0.1-3% by weight, wherein the dose of the one or more rheological modifiers is the final (d) optionally comprising one or more rheological modifiers modified to achieve a bulk viscosity of 150-800 cPs for a barrier coating composition, and one or more auxiliary additives in amounts ranging from 0-10% by weight, 1-9% by weight, 1-8% by weight, 1-6% by weight, or 1-3% by weight when used as a topcoat, and in amounts ranging from 30-70% by weight, 40-60% by weight, or 45-55% by weight when used as a basecoat.

[0274] The at least one biowax emulsion, the one or more rheological modifiers, and optionally the one or more auxiliary additives are dispersed separately or together in the one or more polyacrylate carriers by mechanical mixing to form the barrier coating composition, and in the final form the barrier coating composition contains (i) a total solids content in the range of 30-70% by weight, 40-60% by weight, 45-55% by weight, or 48-52% by weight, or (ii) a bio-based solids content in the range of 40-60% by weight, 45-60% by weight, 50-60% by weight, or 55-60% by weight of the total solids content. (iii) having particle sizes in the range of 0.2-5 μm, 1-4 μm, 2-3 μm, or 2.5-3 μm; (iv) having a bulk viscosity in the range of 40-800 cPs, 100-700 cPs, 150-650 cPs, or 200-400 cPs; (v) comprising a stable dispersion having stability for more than 3 months at 25°C, the stability of which is determined by the barrier coating composition maintaining a 3-month aging viscosity within ±50%, ±40%, ±30%, or ±20% of the bulk viscosity in (iv); or (vi) any combination of one, two, three, four, or all five of (a) to (e).

[0275] In some exemplary embodiments of this method, the barrier coating composition is applied as one or more coatings to a lignocellulose substrate, including, but not limited to, paper, cardboard, cup stock base sheets, bleached sulfate cup stock base sheets, fast food wrappers, or 100% recycled liner board sheets, wherein the one or more coatings are formed at room temperature using a conventional paper coater, roll coater, or metering size press, and subsequently oven-cured for 60-120 seconds, 70-110 seconds, 80-100 seconds, or 90-95 seconds at 100-120°C, 105-115°C, or 108-112°C, and the application of the barrier coating composition is as follows:

[0276] (a) The barrier coating composition forms a single coat layer, a base coat layer, a top coat layer, a double coating comprising a base coat layer and a top coat layer containing the same barrier coating composition, a double coating comprising a base coat layer and a top coat layer containing different barrier coating compositions, or multiple coating layers.

[0277] (b) The one or more coatings provide increased paper fiber strength and reduced paper fiber discoloration compared to biowax coatings applied at temperatures of 60-180°C, 70-170°C, or 80-160°C,

[0278] (c) The one or more coatings provide a barrier against the permeation of one or more oils, greases, or water into or through the lignocellulosic substrate at temperatures in the range of 5 to 95°C, 15 to 90°C, 25 to 85°C, or 40 to 60°C, wherein the barrier against permeation is one or more coatings formed in the same manner from the polyacrylate carrier alone.

[0279] (d) When one or more coatings are applied at a coat weight of 10–30, 16–22, or 18–20 grams (gsm) per square meter, they result in equal or enhanced KIT test values ​​(i.e., measures of oil and grease resistance) and Cobb 30-minute test values ​​(i.e., measures of the mass of water absorbed per square meter over 30 minutes) (i.e., higher KIT values ​​and lower Cobb values) compared to coatings similarly formed from the polyacrylate carrier alone.

[0280] (e) When one or more coatings are applied at a coat weight of 10-30, 16-22, or 18-20 grams (gsm) per square meter, the Cobb 30-minute test results show a decrease dependent on the coat weight,

[0281] (f) The one or more coatings result in a final form containing one or more of the following percentages of bio-based material: ≥50% by weight, 50–65% by weight, 50–60% by weight, or 50–55% by weight.

[0282] In another embodiment, the present invention also provides a sheet product for use as food service packaging, beverage service packaging, or any packaging material suitable for transporting and / or storing materials containing oil, water, and / or grease,

[0283] The present invention provides a sheet-like product comprising: (a) a substrate containing lignocellulose fibers and having a first large parallel surface and a second large parallel surface; and (b) a coating structure comprising a barrier coating composition of any of the aforementioned compositions, applied in at least one layer to at least one of the large surfaces of the substrate, wherein the sheet-like product has (i) a KIT test value of 11-12 or 12, and / or (ii) a Cobb 30-minute value of less than 5 gsm.

[0284] The present invention also relates to a sheet product for use as food service packaging, beverage service packaging, or any packaging material suitable for transporting and / or storing materials containing oil, water, and / or grease,

[0285] The present invention provides a sheet product comprising: (a) a substrate containing lignocellulose fibers and having a first large parallel surface and a second large parallel surface; and (b) a coating structure comprising a barrier coating composition prepared by any of the above methods, applied in at least one layer to at least one of the large surfaces of the substrate, wherein the sheet product has (i) a KIT test value of 11-12 or 12, and / or (ii) a Cobb 30-minute value of less than 5 gsm.

[0286] The methods and compositions disclosed illustratively herein can be suitably practiced without any element not specifically disclosed herein and / or in the absence of any element specifically disclosed herein. Exemplary embodiments of the invention and their advantages are further disclosed in the following examples.

Examples

[0287] The examples provided herein are for illustrative purposes so that the invention can be more fully understood. These examples should not be construed as limiting the invention in any way.

[0288] Example 1: Preparation of Barrier Coating Composition A barrier coating composition was prepared for evaluation as a coating for paper or cardboard.

[0289] Bio - wax emulsion

[0290]

Table 1

[0291] * Non - ionic surfactants: ethoxylated alcohols and esters; Anionic surfactants: fatty alcohol ether sulfates, alkyl ether sulfates, special soaps

[0292] A high - solids bio - wax emulsion (total solids, TS > 50%) was prepared from castor wax, rosin size, non - ionic and anionic surfactants, microcrystalline wax, long - chain fatty acids, and optional additives according to Table 1. The components were blended to form a reverse - phase emulsion and then cooled using a rapid cooling process.

[0293] The components shown in Table 1 were combined in a reactor and heated to a temperature in the range of 90-95°C to form an oil phase, thereby forming a reverse-phase emulsion. A certain amount of hot water was then added. The mixture was emulsified and homogenized at 75-98°C for 0.5-4 hours, and then cooled to a temperature in the range of 15-25°C. Rapid cooling of the resulting reverse-phase emulsion was achieved by cooling it to a temperature in the range of 15-25°C using an ice bath, cooling jacket, or cooling core. A biocide was then added.

[0294] The final biowax emulsion BE1 obtained a bulk viscosity of 1600 cPs and a total solids content of 56%.

[0295] Barrier coating composition (BCC)

[0296] [Table 2]

[0297] *Aqueous polyacrylate dispersion with 50% by weight of dry total solids

[0298] **Pre-hydrated Ticaloid 5415**

[0299] Barrier coating compositions (BCC1-2) were prepared by combining a high-solids biowax emulsion (BE1), a rheology modifier, and an optional auxiliary additive, as shown in Table 2, with a polyacrylate support.

[0300] The polyacrylate support acts as a paper barrier coating with both oil and water barrier properties, but has insufficient barrier properties. It is an aqueous dispersion of polyacrylate (50% total dry solids) made from 100% fossil-based raw materials and was used as control 1.

[0301] The barrier coating composition of the present invention was formed by directly dispersing the components shown in Table 2 onto a polyacrylate carrier to form a stable biowax barrier coating dispersion having a final bulk viscosity generally in the range of 80 to 600 cPs.

[0302] Where indicated, a low dose range of clay was added to stabilize the final barrier coating dispersion. The clay was formulated as an aqueous slurry with a total solids content of 70% by weight before being dispersed in the barrier coating composition.

[0303] As indicated, microcrystalline cellulose (MCC) has the ability to provide barrier-enhancing properties. MCC having an average particle size in the range of 3 to 6 μm was added as a spray-dried powder and dispersed in a polyacrylate carrier.

[0304] The bulk viscosity of the final biowax barrier coating dispersion was controlled within the range of 100–600 cPs by varying the dosage of the bio-based rheology modifier, pre-hydrated Ticaloid 5415. The final bulk viscosity was selected to be suitable for use in either a conventional paper coater or a metering size press at room temperature.

[0305] Stability tests were performed by aging the biowax barrier coating dispersion at 25°C for 3 months with an initial bulk viscosity of 540 cPs. After 3 months of aging, the viscosity increased to 720 cPs, which corresponds to a 33% increase, indicating high stability at room temperature.

[0306] The properties of the final barrier coating composition (BCC) are listed in Table 3.

[0307] [Table 3]

[0308] These results provide the first proof of concept that a barrier coating composition dispersion having high stability (> 3 months), high total solids (> 50%), and a high proportion of solids from a bio-based content (i.e., a sustainable and renewable source) can be provided by dispersing a biowax emulsion in a polyacrylate carrier. The bulk viscosity was suitable for use on either a conventional paper coater or a metering size press machine under room temperature conditions.

[0309] Example 2: Evaluation of Barrier Coatings for Recycled Linerboard Sheets The substrate for the barrier coating was a 100% recycled linerboard base sheet that was not surface sized and slightly internally sized.

[0310] Barrier coating compositions (Control 1, BCC1, and BCC2) were applied by roller coating to a recycled linerboard base sheet at a single coat weight and subsequently oven cured at 110 °C for 90 seconds. A double coating (the same barrier coating composition for both the top coat and the base coat) of each barrier coating composition was applied to a single side of the recycled linerboard base sheet. After each coat application, oven curing was performed.

[0311] Two barrier-coated paper tests were performed to evaluate the barrier coatings. Cobb 5-minute and Cobb 30-minute tests were performed to determine the mass of water that can be absorbed by the surface of the paper or paperboard in g / m 2 (gsm) units over a given time (e.g., 5 minutes or 30 minutes). A KIT test was performed to measure the oil and grease resistance (OGR) level of the sheet. The KIT test values range from 1 to 12, where 1 indicates no OGR barrier and 12 indicates very good OGR.

[0312] Table 4 lists the properties of uncoated 100% recycled linerboard base sheets, including the results of uncoated KIT tests and Cobb 5-minute tests.

[0313] [Table 4]

[0314] Table 5 lists the characteristics of barrier-coated 100% recycled linerboard base sheets.

[0315] [Table 5]

[0316] These results demonstrate that barrier coating compositions containing biowax emulsion dispersed on a polyacrylate support deliver comparable KIT values, exhibiting equivalent oil and water resistance properties compared to a polyacrylate dispersion control. BCC1 provides an improved Cobb30 value, demonstrating improved water resistance compared to the control.

[0317] These results provide the first proof of the concept that this biowax-based barrier coating composition can be effectively used in coated sheet products for use as food service packaging, beverage service packaging, or any packaging suitable for the transport and / or storage of materials containing oil, water, and / or grease.

[0318] Example 3: Evaluation of barrier coating for cup stock base sheet The base material for barrier coatings has a basic weight of 273 g / m². 2 The cup stock base sheet had a 40gsm Cobb 5 minute thickness for the bottom (rough surface).

[0319] Barrier coating compositions (Control 1, BCC1, and BCC2) were applied to recycled cup stock base sheets by roller coating at 13, 17, and 19 g / m², respectively. 2 The coating was applied at (gsm) weight and then oven-cured at 110°C for 90 seconds. A double coating of each barrier coating composition (the same barrier coating composition for the top coat and base coat) was applied to a single side of the base sheet. After each coat application, oven curing was performed.

[0320] A KIT test was performed to evaluate OGR, and a Cobb 30-minute test was performed to evaluate the water resistance of the barrier-coated cup stock base sheet.

[0321] The results of the Cobb 30-minute test are shown in Figure 1. All barrier-coated samples achieved a KIT value of 12.

[0322] These results show a dose-dependent improvement in water resistance for all barrier coating compositions. BCC1 with a 43% bio-content yielded the same water resistance as the control with a 0% bio-content. In the BCC2 barrier dispersion, increasing the bio-content to 50% increased the Cobb value and decreased the water barrier properties. All barrier-coated samples achieved a KIT value of 12, indicating excellent OGR. Paper sheets coated with BCC1 and BCC2 exhibited significantly better barrier properties than the control coated sheet.

[0323] These results provide further proof of the concept that this biowax-based barrier coating composition can be effectively used in coated sheet products for use as food service packaging, beverage service packaging, or any packaging suitable for the transport and / or storage of materials containing oil, water, and / or grease. Different coated paper grades require different coat weight ranges. For example, cup stock requires 20-25 grams (gsm) per m2, while fast food wrappers require 6-10 gsm.

[0324] Example 4: Evaluation of auxiliary additives in barrier coatings for cup stock base sheets The substrate for the barrier coating was the cup stock base sheet described in Example 3.

[0325] [Table 6]

[0326] *Aqueous polyacrylate (PA) dispersion with 50% by weight of dry total solids.

[0327] **Pre-hydrated Ticaloid 5415**

[0328] Barrier coating compositions (BCC3-4) for use as a base coat were prepared by combining a high-solids biowax emulsion (BE1), a rheology modifier, and an optional auxiliary additive shown in Table 6 with a polyacrylate support using the method of Example 1.

[0329] Clay and microcrystalline cellulose (MCC) in the base coat formulation were evaluated as auxiliary additives to provide enhanced water barrier properties to the top coat barrier coating composition. Clay and MCC in the base coat also contribute to the bio-based / natural material content of the barrier coating.

[0330] Base coat: Barrier coating composition BCC2 (neither clay nor MCC), barrier coating BCC3 having clay (50% dry weight), and BCC4 having clay (47% dry weight) and MCC (3% dry weight) were applied as a base coat to a cup stock base sheet by roller coating, and then cured in an oven at 110°C for 90 seconds.

[0331] Top coat: Barrier coating compositions BCC1 and BCC2 (neither clay nor MCC) were applied to the cup stock base sheet as a top coat by roller coating, and then cured in an oven at 110°C for 90 seconds.

[0332] Table 7 lists the base coats and top coats for barrier-coated cup stock samples 1-4. The total coat weight and bio-content percentage, expressed as the total coating solids percentage, are also shown.

[0333] A KIT test was performed to evaluate OGR, and a Cobb 30-minute test was performed to evaluate the water resistance of barrier-coated cup stock samples 1-3. The results are shown in Table 7.

[0334] Formulation targets: (i) Bio-content exceeding 50% in the two coating layers (renewable raw materials), (ii) <5g / m² 2 The Cobb value (30 minutes) and (iii) KIT value = 12 for the two-layer coated sheet.

[0335] [Table 7]

[0336] These results indicate that the addition of clay to the base coat (Sample 2) dramatically improved water barrier performance. The addition of clay and MCC (Sample 3) provided further improvement in water barrier performance. All barrier-coated samples achieved 12 KIT values, indicating excellent OGR. Of the samples tested, only Sample 3 met all three formulation targets for bio content, Cobb 30-minute value, and KIT value.

[0337] These results provide the first proof of the concept that the addition of auxiliary additives (e.g., clay and MCC) to the base coat formulation enhances both the bio-content and water resistance of the double-coated paper. In summary, these results provide further proof of the concept that this biowax-based barrier coating composition having clay and MCC in the base coat can be effectively used in coated sheet products for use as food service packaging, beverage service packaging, or any packaging suitable for transporting and / or storing materials containing oil, water, and / or grease.

[0338] Example 5: Evaluation of barrier coating BCC2 vs. PHA for white cup stock base sheets The base material for barrier coatings has a basic weight of 273 g / m². 2 The top surface was a solid bleached sulfate (SBS) white cup stock cardboard base sheet with 42 gsm Cobb for 5 minutes.

[0339] The barrier coating composition (BCC2) was evaluated as a coating material versus a bio-based polyhydroxyalkanoate (PHA) barrier coating dispersion, and this was applied to a cup stock base sheet at a rate of approximately 22 g / m² using a cup stock coater. 2 The coating was applied at a coat weight of (gsm). A double coating of each barrier coating composition (the same barrier coating composition for the top coat and base coat) was applied to a single side of the base sheet.

[0340] The KIT test was performed to evaluate the OGR, and the Cobb 30-minute test was performed to evaluate the water resistance of the barrier-coated cupstock base sheet.

[0341] Target water barrier: Cobb 30-minute < 5 g / m for use in food service products such as cold and hot cups 2 The characteristics of the barrier-coated cupstock samples are listed in Table 8.

[0342]

Table 8

[0343] These results indicate that BCC2, a bio-based castor oil wax dispersed in polyacrylate, delivered an equivalent water barrier and far superior oil and grease resistance compared to the PHA dispersion for cupstock coating. The BCC2 barrier coating achieved a Cobb 30-minute < 5 g / m, indicating its suitability for use in food service products such as cold and hot cups. 2 was achieved. In the foregoing disclosure including the examples, different procedures and various steps are described. However, it will be apparent that various modifications and changes can be made thereto and additional procedures can be implemented without departing from the broader scope of the procedures described in the following claims.

Claims

1. A barrier coating composition for paper or cardboard, wherein the barrier coating composition is (a) One or more biowax emulsions, (b) One or more polyacrylate carriers, (c) optionally comprising one or more auxiliary additives, The one or more biowax emulsions described above (i) Optionally, one or more biowaxes including palm oil wax, castor oil wax, soybean oil wax, fish oil wax, animal fat wax, vegetable oil wax, animal fat wax, a blend of vegetable oil wax and animal fat wax, or any combination thereof, (ii) Optionally, one or more rosin sizing agents comprising reinforced rosin, esterified rosin, rosin wax, resin acid derivative, gum rosin, wood rosin, tall oil rosin, rosin paste, rosin-based dispersion, or any combination thereof, (iii) Optionally, one or more surfactants comprising one or more nonionic surfactants, one or more anionic surfactants, or a combination thereof, wherein (a) the one or more nonionic surfactants include, but are not limited to, ethoxylated alcohols such as secondary alcohol ethoxylates, ethoxylated sorbitan esters, sorbitan esters, but are not limited to glycerol esters such as glycerol monostearate (GMS), and any combination thereof, and (b) the one or more anionic surfactants include, but are not limited to, fatty alcohol ether sulfates, alkyl ether sulfates, special soaps such as anionic long-chain fatty acids, and any combination thereof, (iv) Optionally, one or more microcrystalline or paraffinic waxes having a freezing point of 50-110°C, 65-100°C, 70-90°C, or 75-85°C, comprising saturated hydrocarbon waxes, paraffinic hydrocarbon waxes, isoparaffinic hydrocarbon waxes, naphthenic hydrocarbon waxes, and mixtures thereof, (v) A barrier coating composition comprising, optionally, one or more long-chain fatty acids having carbon chain lengths in the range of C18-C30, C20-C30, C22-C30, or C24-C30.

2. The barrier coating composition according to claim 1, further comprising one or more rheological modifiers.

3. The one or more biowaxes described above (a) comprising one or more hydrogenated bio-based oils, including but not limited to palm oil, castor oil, soybean oil, fish oil, animal fat oil, vegetable oil, animal oil, blends of vegetable oil and animal oil, or any combination thereof, wherein each of the hydrogenated bio-based oils has a higher melting point than the corresponding unhydrogenated bio-based oil, and (b) The barrier coating composition according to claim 1 or 2, having a melting point of 55-98°C, 60-95°C, 65-90°C, 70-85°C, or 75-80°C.

4. The one or more biowax emulsions described above (a) The one or more biowaxes include castor oil wax, (b) The one or more rosin sizing agents include reinforced rosin sizing, (c) The nonionic surfactant comprises a secondary alcohol ethoxylate, glycerol monostearate (GMS), or a combination thereof, and the anionic surfactant comprises an anionic long-chain fatty acid, or a combination thereof. (d) The one or more microcrystalline or paraffinic waxes have a freezing point of 70 to 90°C, (e) The barrier coating composition according to claim 1, 2, or 3, wherein one or more long-chain fatty acids have a carbon chain length in the range of C22 to C30.

5. The one or more biowax emulsions described above (a) one or more of the biowaxes in an amount in the range of 20-60% by weight, 25-55% by weight, 30-50% by weight, or 35-45% by weight, (b) One or more of the rosin sizing agents in an amount in the range of 1 to 12% by weight, 2 to 10% by weight, 3 to 8% by weight, or 4 to 6% by weight, (c) One or more surfactants in an amount in the range of 2 to 12% by weight, 4 to 10% by weight, or 6 to 8% by weight, (d) One or more of the above microcrystalline or paraffinic waxes in an amount ranging from 2 to 10% by weight, 3 to 9% by weight, 4 to 8% by weight, or 5 to 7% by weight, (e) The barrier coating composition according to any one of the prior claims, comprising, optionally, one or more long-chain fatty acids in an amount ranging from 0.5 to 6% by weight, 1 to 5% by weight, or 2 to 4% by weight.

6. The one or more biowax emulsions described above (a) Combining one or more biowaxes, one or more rosin sizing agents, one or more surfactants, one or more microcrystalline or paraffinic waxes, and optionally one or more long-chain fatty acids in a reactor, and optionally heating to 70-99°C, 75-98°C, 85-95°C, or 90-95°C to form an oil phase, (b) Adding a certain amount of hot water to the oil phase, wherein the hot water is optionally 70-99°C, 75-98°C, 85-95°C, or 90-95°C. (c) Emulsifying at 70-99°C, 75-98°C, or 85-95°C for a time period of 0.5-5 hours, 0.5-4 hours, or 1-3 hours, as optional. (d) Homogenization and (e) Optionally, the obtained reverse-phase Biomax emulsion is cooled to a temperature in the range of 10–35°C, 15–30°C, or 20–25°C using an ice bath, cooling jacket, or cooling core. (f) optionally adding a biocide, and comprising a reversed-phase biowax emulsion formed by the above, the barrier coating composition according to any of the prior claims.

7. The one or more biowax emulsions described above are in their final form. (a) comprising a total solids content in the range of 50-80% by weight, 50-70% by weight, 50-60% by weight, or 55-57% by weight, wherein ≥ 50% by weight of the total solids content is bio-based and / or (b) A barrier coating composition according to any one of the prior claims, having a final bulk viscosity in the range of 1400 to 1800 cPs, 1500 to 1700 cPs, 1550 to 1650 cPs, or 1590 to 1610 cPs.

8. (a) The one or more polyacrylate carrier comprises an aqueous polyacrylate dispersion containing one or more polyacrylate polymers having a weight-average molecular weight of 10,000 to 1,000,000 Da, 100,000 to 800,000 Da, or 200,000 to 600,000 Da, wherein the aqueous polyacrylate dispersion has a total dry solids content in the range of 40 to 60% by weight, 45 to 55% by weight, or 49 to 51% by weight. (b) The one or more rheological modifiers include, but are not limited to, one or more bio-based gums, such as pre-hydrated cellulose gum, xanthan gum, or mixtures thereof; one or more bio-based hydrocolloids; but are not limited to, one or more polyacrylate dispersions having a charge in the range of 70-100 mol%, 80-100 mol%, or 90-100 mol% and a molecular weight in the range of 1,000-100,000 Da, 2,000-80,000 Da, or 10,000-50,000 Da; or a combination thereof. (c) The one or more auxiliary additives are selected from clay, kaolin, alumina, silica, nanoclay, nanocellulose, nanostructured cellulose, cellulose nanofiber (CNF), nanofibrillated cellulose (NFC), bacterial nanocellulose, cellulose nanocrystals (CNC), microfibrillated cellulose (MFC), and microcrystalline cellulose (MCC), and any combination thereof. (d) Any combination of (a), (b), and (c), the barrier coating composition according to any one of the prior claims.

9. In the one or more auxiliary additives, (a) The clay and / or nanoclay is formulated as an aqueous slurry having a total solids content of 60-80% by weight, 65-75% by weight, or 68-72% by weight before being dispersed in the barrier coating composition. (b) The cellulose nanocrystals (CNCs) are incorporated as an aqueous slurry or spray-dried powder before being dispersed in the barrier coating composition, and optionally produced by acid hydrolysis of cellulose. (c) The microfibrillated cellulose (MFC) is (i) having an average particle length in the range of 20-200 μm, 50-200 μm, 100-200 μm, or 150-200 μm, (ii) having an average particle width in the range of 0.1-1 μm, 0.2-1 μm, 0.4-1 μm, or 0.6-1 μm, and (iii) being formulated as an aqueous solution having a dry content of 10-30% by weight, 15-25% by weight, or 18-22% by weight before being formulated with the barrier coating composition. (d) The barrier coating composition according to claim 8, wherein the microcrystalline cellulose (MCC) (i) has an average particle size in the range of 1 to 8 μm, 2 to 7 μm, 3 to 6 μm, or 4 to 5 μm, and (ii) is formulated as an aqueous slurry or spray-dried powder before being dispersed in the barrier coating composition.

10. (a) The one or more rheological modifiers include pre-hydrated cellulose gum and xanthan gum, (b) The barrier coating composition according to any one of the prior claims, wherein the one or more auxiliary additives include clay, nanoclay, microcrystalline cellulose (MCC), or a combination thereof.

11. The barrier coating composition is (a) one or more of the biowax emulsions in an amount in the range of 20 to 80% by weight, 30 to 70% by weight, or 40 to 60% by weight, (b) One or more of the polyacrylate carriers in an amount in the range of 20 to 80% by weight, 30 to 70% by weight, or 40 to 60% by weight, (c) One or more rheological modifiers in an amount ranging from 0.1 to 5% by weight, 0.1 to 4% by weight, or 0.1 to 3% by weight, further comprising one or more rheological modifiers, wherein the dosage of the one or more rheological modifiers is modified to achieve a bulk viscosity of 150 to 800 cPs of the barrier coating composition in the final form. (d) A barrier coating composition according to any one of the prior claims, comprising, when used as a top coat, one or more of the auxiliary additives in an amount ranging from 0 to 10% by weight, 1 to 9% by weight, 1 to 8% by weight, 1 to 6% by weight, or 1 to 3% by weight, and when used as a base coat, 30 to 70% by weight, 40 to 60% by weight, or 45 to 55% by weight.

12. The barrier coating composition comprises a stable dispersion formed by dispersing one or more biowax emulsions, one or more rheological modifiers, and one or more auxiliary additives separately or together in one or more polyacrylate carriers using mechanical mixing to form a stable dispersion, and the barrier coating composition in its final form is (a) containing a total solids content in the range of 30-70% by weight, 40-60% by weight, 45-55% by weight, or 48-52% by weight, (b) comprising a bio-based solids content in the range of 40-60% by weight, 45-60% by weight, 50-60% by weight, or 55-60% by weight of the total solids content, (c) Having particle sizes in the range of 0.2 to 5 μm, 1 to 4 μm, 2 to 3 μm, or 2.5 to 3 μm, (d) Having a bulk viscosity in the range of 40-800 cPs, 100-700 cPs, 150-650 cPs, or 200-400 cPs, (e) The barrier coating composition having stability for more than 3 months at 25°C, and the stability is determined by maintaining an aging viscosity within ±50%, ±40%, ±30%, or ±20% of the bulk viscosity in (d), (f) A barrier coating composition according to any one of the prior claims, which is any combination of one, two, three, four, or all five of (a) to (e).

13. When applied as one or more coatings to a lignocellulose substrate, including but not limited to paper, cardboard, cup stock base sheets, bleached sulfate cup stock base sheets, fast food wrappers, or 100% recycled linerboard sheets, The one or more coatings are formed at room temperature using a conventional paper coater, roll coater, or metering size press, and then oven-cured for 60-120 seconds, 70-110 seconds, 80-100 seconds, or 90-95 seconds at 100-120°C, 105-115°C, or 108-112°C, and then: (a) The barrier coating composition forms a single coat layer, a base coat layer, a top coat layer, a double coating comprising a base coat layer and a top coat layer containing the same barrier coating composition, a double coating comprising a base coat layer and a top coat layer containing different barrier coating compositions, or multiple coating layers. (b) The one or more coatings provide increased paper fiber strength and reduced paper fiber discoloration compared to biowax coatings applied at temperatures of 60-180°C, 70-170°C, or 80-160°C, (c) The one or more coatings provide a barrier against the permeation of one or more oils, greases, or water into or through the lignocellulose substrate at temperatures in the range of 5 to 95°C, 15 to 90°C, 25 to 85°C, or 40 to 60°C, wherein the barrier against permeation is one or more coatings formed in the same manner from the polyacrylate carrier alone. (d) When one or more coatings are applied at a coating weight of 10 to 30, 16 to 22, or 18 to 20 grams (gsm) per square meter, they result in equal or enhanced KIT test values ​​(i.e., measures of oil and grease resistance) and Cobb 30-minute test values ​​(i.e., measures of the mass of water absorbed per square meter over 30 minutes) (i.e., higher KIT values ​​and lower Cobb values) compared to coatings similarly formed from the polyacrylate carrier alone. (e) When one or more coatings are applied at a coat weight of 10 to 30, 16 to 22, or 18 to 20 grams (gsm) per square meter, the Cobb 30-minute test results show a decrease dependent on the coat weight, (f) The barrier coating composition according to any of the prior claims, wherein one or more coatings in the final form contain one or more of the following percentages of bio-based material: ≥ 50% by weight, 50-65% by weight, 50-60% by weight, or 50-55% by weight.

14. A method for preparing a barrier coating composition for paper or cardboard according to any one of the prior claims, wherein the method is (a) Forming at least one biowax emulsion, (b) Forming or providing one or more polyacrylate carriers, (c) Dispersing the at least one biowax emulsion in the one or more polyacrylate carriers, (d) Optionally, dispersing one or more rheological modifiers in the one or more polyacrylate carriers, (e) optionally dispersing one or more auxiliary additives in the one or more polyacrylate carriers, A method in which steps (c) to (e) are carried out together or separately.

15. The at least one biowax emulsion is (a) One or more biowaxes selected from the group consisting of palm oil wax, castor oil wax, soybean oil wax, fish oil wax, animal fat wax, vegetable oil wax, animal fat wax, blends of vegetable oil wax and animal fat wax, or any combination thereof, The one or more biowaxes include (i) one or more hydrogenated bio-based oils, each of which has a higher melting point than the corresponding unhydrogenated bio-based oil, and (ii) one or more biowaxes having a melting point of 55-98°C, 60-95°C, 65-90°C, 70-85°C, or 75-80°C. (b) One or more rosin sizing agents, including but not limited to reinforced rosin, esterified rosin, rosin wax, resin acid derivatives, gum rosin, wood rosin, tall oil rosin, rosin paste, rosin-based dispersions, or any combination thereof, (c) One or more surfactants comprising a nonionic surfactant, anionic surfactant, or a combination thereof, wherein (i) the nonionic surfactant is selected from ethoxylated alcohols (not limited to secondary alcohol ethoxylates), ethoxylated sorbitan esters, sorbitan esters, glycerol esters (not limited to glycerol monostearate (GMS)), and any combination thereof, and (ii) the anionic surfactant is selected from one or more surfactants comprising fatty alcohol ether sulfates, alkyl ether sulfates, special soaps (not limited to anionic long-chain fatty acids), and any combination thereof, (d) One or more microcrystalline or paraffinic waxes having a freezing point of 50-110°C, 65-100°C, 70-90°C, or 75-85°C, including but not limited to saturated hydrocarbon waxes, paraffinic hydrocarbon waxes, isoparaffinic hydrocarbon waxes, naphthenic hydrocarbon waxes, and mixtures thereof, (e) The method according to claim 14, comprising, optionally, one or more long-chain fatty acids having a carbon chain length in the range of C18-C30, C20-C30, C22-C30, or C24-C30.

16. The at least one biowax emulsion is (a) one or more of the biowaxes in an amount in the range of 20-60% by weight, 25-55% by weight, 30-50% by weight, or 35-45% by weight, (b) One or more of the rosin sizing agents in an amount in the range of 1 to 12% by weight, 2 to 10% by weight, 3 to 8% by weight, or 4 to 6% by weight, (c) One or more surfactants in an amount in the range of 2 to 12% by weight, 4 to 10% by weight, or 6 to 8% by weight, (d) One or more of the above microcrystalline or paraffinic waxes in an amount ranging from 2 to 10% by weight, 3 to 9% by weight, 4 to 8% by weight, or 5 to 7% by weight, (e) optionally comprising one or more of the above long-chain fatty acids in an amount ranging from 0.5 to 6% by weight, 1 to 5% by weight, or 2 to 4% by weight, The at least one biowax emulsion is (i) Combining one or more biowaxes, one or more rosin sizing agents, one or more surfactants, one or more microcrystalline or paraffinic waxes, and optionally one or more long-chain fatty acids in a reactor, and optionally heating to 70-99°C, 75-98°C, 85-95°C, or 90-95°C to form an oil phase, (ii) Adding a certain amount of hot water to the oil phase, wherein the hot water is optionally 70-99°C, 75-98°C, 85-95°C, or 90-95°C. (iii) Emulsification at 70-99°C, 75-98°C, or 85-95°C for a time period of 0.5-5 hours, 0.5-4 hours, or 1-3 hours, as optional. (iv) Homogenization and (v) Optionally, the obtained reversed-phase biowax emulsion is cooled to a temperature in the range of 10–35°C, 15–30°C, or 20–25°C using an ice bath, cooling jacket, or cooling core. (vi) optionally adding a biocide, and comprising a reversed-phase biowax emulsion formed by the method of claim 14 or 15.

17. The aforementioned at least one biowax emulsion, in its final form, (a) A total solids content in the range of 50-80% by weight, 50-70% by weight, 50-60% by weight, or 55-57% by weight, wherein ≥ 50% by weight of the total solids content is bio-based, (b) The method according to any one of claims 14, 15, or 16, having a final bulk viscosity in the range of 1400 to 1800 cPs, 1500 to 1700 cPs, 1550 to 1650 cPs, or 1590 to 1610 cPs.

18. (a) The one or more polyacrylate carrier comprises an aqueous polyacrylate dispersion containing one or more polyacrylate polymers having a weight-average molecular weight of 10,000 to 1,000,000 Da, 100,000 to 800,000 Da, or 200,000 to 600,000 Da, wherein the aqueous polyacrylate dispersion has a total dry solids content in the range of 40 to 60% by weight, 45 to 55% by weight, or 49 to 51% by weight. (b) The one or more rheological modifiers include, but are not limited to, one or more bio-based gums, such as pre-hydrated cellulose gum, xanthan gum, or mixtures thereof; one or more bio-based hydrocolloids; but are not limited to, one or more polyacrylate dispersions having a charge in the range of 70-100 mol%, 80-100 mol%, or 90-100 mol% and a molecular weight in the range of 1,000-100,000 Da, 2,000-80,000 Da, or 10,000-50,000 Da; or a combination thereof. (c) The one or more auxiliary additives are selected from clay, kaolin, alumina, silica, nanoclay, nanocellulose, nanostructured cellulose, cellulose nanofiber (CNF), nanofibrillated cellulose (NFC), bacterial nanocellulose, cellulose nanocrystals (CNC), microfibrillated cellulose (MFC), and microcrystalline cellulose (MCC), and any combination thereof. (i) The clay and / or nanoclay is formulated as an aqueous slurry having a total solids content of 60-80% by weight, 65-75% by weight, or 68-72% by weight before being dispersed in the barrier coating composition using a mechanical mixing device, (ii) The cellulose nanocrystals (CNCs) are formulated as an aqueous slurry or spray-dried powder before being dispersed in the barrier coating composition using a mechanical mixing device, and optionally produced by acid hydrolysis of cellulose. (iii) The microfibrillated cellulose (MFC) is (i) having an average particle length in the range of 20-200 μm, 50-200 μm, 100-200 μm, or 150-200 μm, (ii) having an average particle width in the range of 0.1-1 μm, 0.2-1 μm, 0.4-1 μm, or 0.6-1 μm, and (iii) being formulated as an aqueous solution having a dry content of 10-30% by weight, 15-25% by weight, or 18-22% by weight before being formulated with the barrier coating composition. (iv) The method according to any one of claims 14 to 17, wherein the microcrystalline cellulose (MCC) (i) has an average particle size in the range of 1 to 8 μm, 2 to 7 μm, 3 to 6 μm, or 4 to 5 μm, and (ii) is formulated as an aqueous slurry or spray-dried powder before being dispersed in the barrier coating composition using a mechanical mixing device.

19. The barrier coating composition is (a) an amount of at least one biowax emulsion in the range of 20 to 80% by weight, 30 to 70% by weight, or 40 to 60% by weight, (b) One or more of the polyacrylate carriers in an amount in the range of 20 to 80% by weight, 30 to 70% by weight, or 40 to 60% by weight, (c) One or more rheological modifiers in an amount ranging from 0.1 to 5% by weight, 0.1 to 4% by weight, or 0.1 to 3% by weight, further comprising one or more rheological modifiers, wherein the dosage of the one or more rheological modifiers is modified to achieve a bulk viscosity of 150 to 800 cPs of the barrier coating composition in the final form. (d) optionally comprising one or more of the above auxiliary additives, in amounts ranging from 0 to 10% by weight, 1 to 9% by weight, 1 to 8% by weight, 1 to 6% by weight, or 1 to 3% by weight when used as a top coat, and in amounts ranging from 30 to 70% by weight, 40 to 60% by weight, or 45 to 55% by weight when used as a base coat. The at least one biowax emulsion, the one or more rheological modifiers, and optionally the one or more auxiliary additives are dispersed separately or together in the one or more polyacrylate carriers by mechanical mixing to form the barrier coating composition, and in the final form the barrier coating composition, (i) containing a total solids content in the range of 30-70% by weight, 40-60% by weight, 45-55% by weight, or 48-52% by weight, (ii) containing a bio-based solid content in the range of 40-60% by weight, 45-60% by weight, 50-60% by weight, or 55-60% by weight of the total solid content, (iii) Having particle sizes in the range of 0.2 to 5 μm, 1 to 4 μm, 2 to 3 μm, or 2.5 to 3 μm, (iv) Having a bulk viscosity in the range of 40-800 cPs, 100-700 cPs, 150-650 cPs, or 200-400 cPs, (v) comprising a stable dispersion having stability for more than 3 months at 25°C, the stability of which is determined by the barrier coating composition that maintains a 3-month aging viscosity within ±50%, ±40%, ±30%, or ±20% of the bulk viscosity in (iv), or (vi) The method according to any one of claims 14 to 17, which is any combination of one, two, three, four, or all five of (a) to (e).

20. The barrier coating composition is applied as one or more coatings to a lignocellulose substrate, including, but not limited to, paper, cardboard, cup stock base sheets, bleached sulfate cup stock base sheets, fast food wrappers, or 100% recycled liner board sheets, wherein the one or more coatings are formed at room temperature using a conventional paper coater, roll coater, or metering size press, and subsequently oven-cured for 60-120 seconds, 70-110 seconds, 80-100 seconds, or 90-95 seconds at 100-120°C, 105-115°C, or 108-112°C, wherein the application of the barrier coating composition is as follows: (a) The barrier coating composition forms a single coat layer, a base coat layer, a top coat layer, a double coating comprising a base coat layer and a top coat layer containing the same barrier coating composition, a double coating comprising a base coat layer and a top coat layer containing different barrier coating compositions, or multiple coating layers. (b) The one or more coatings provide increased paper fiber strength and reduced paper fiber discoloration compared to biowax coatings applied at temperatures of 60-180°C, 70-170°C, or 80-160°C, (c) The one or more coatings provide a barrier against the permeation of one or more oils, greases, or water into or through the lignocellulose substrate at temperatures in the range of 5 to 95°C, 15 to 90°C, 25 to 85°C, or 40 to 60°C, wherein the barrier against permeation is one or more coatings formed in the same manner from the polyacrylate carrier alone. (d) When one or more coatings are applied at a coating weight of 10 to 30, 16 to 22, or 18 to 20 grams (gsm) per square meter, they result in equal or enhanced KIT test values ​​(i.e., measures of oil and grease resistance) and Cobb 30-minute test values ​​(i.e., measures of the mass of water absorbed per square meter over 30 minutes) (i.e., higher KIT values ​​and lower Cobb values) compared to coatings similarly formed from the polyacrylate carrier alone. (e) When one or more coatings are applied at a coat weight of 10 to 30, 16 to 22, or 18 to 20 grams (gsm) per square meter, the Cobb 30-minute test results show a decrease dependent on the coat weight, (f) The method of claim 14, wherein the one or more coatings in the final form contain one or more of the following percentages of bio-based material: ≥ 50% by weight, 50-65% by weight, 50-60% by weight, or 50-55% by weight.

21. A sheet-like product for use as food service packaging, beverage service packaging, or any packaging material suitable for transporting and / or storing materials containing oil, water, and / or grease, (a) A substrate containing lignocellulose fibers and having a first large parallel surface and a second large parallel surface, (b) A coating structure comprising the barrier coating composition according to any one of claims 1 to 13, applied in at least one layer to at least one of the larger surfaces of the substrate, The aforementioned sheet-like product (i) KIT test values ​​of 11-12, or 12, and / or (ii) A sheet-like product having a Cobb 30-minute value of less than 5 gsm.

22. A sheet-like product for use as food service packaging, beverage service packaging, or any packaging material suitable for transporting and / or storing materials containing oil, water, and / or grease, (a) A substrate containing lignocellulose fibers and having a first large parallel surface and a second large parallel surface, (b) A coating structure comprising a barrier coating composition prepared according to any one of claims 14 to 20, applied in at least one layer to at least one of the larger surfaces of the substrate, The aforementioned sheet-like product (i) KIT test values ​​of 11-12, or 12, and / or (ii) A sheet-like product having a Cobb 30-minute value of less than 5 gsm.

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