Biowax polyhydroxyalkanoate dispersion as a bio-based barrier coating

Abstract

The present invention relates to compositions and methods for forming substantially bio-based barrier coatings suitable for application to paper and cardboard substrates, and to paper and cardboard substrates coated with one or more layers of such substantially bio-based barrier coatings. 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 polyhydroxyalkanoate (PHA) 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 / 456,169 filed on 31 March 2023 and Finnish Application No. 20235947 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, there is an unmet market need for a substantially bio-based barrier coating for paper and cardboard that has a high bio-based content (>50% of total coating solids) and can be applied at room temperature using a conventional paper coater or metering size press without damaging or discoloring the paper / cardboard substrate. Creating coating dispersions with high bio-content 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 project]

[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 by employing a biowax emulsion, a polyhydroxyalkanoate (PHA) 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 polyhydroxyalkanoates (PHA) together with auxiliary additives (e.g., clay, MCC, etc.) when used to coat paper and / or cardboard has (i) a bio-content of more than 50% in one coating layer (renewable raw materials), and (ii) <6 g / m² 2 The single-layer coated sheet achieved excellent oil and water barrier properties, including a Cobb value (1 minute) and (iii) a KIT value of 12.

[0013] In one embodiment, the present invention provides a barrier coating composition, optionally an oil barrier coating composition for use on a paper or board substrate, said barrier coating composition

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

[0015] (b) One or more polyhydroxyalkanoates (PHA), and

[0016] (c) One or more rheology modifiers, and

[0017] (d) One or more auxiliary additives.

[0018] In some exemplary embodiments, the one or more biowax emulsions are

[0019] (a) One or more biowaxes including palm oil wax, castor oil wax, soybean oil wax, fish oil wax, tallow oil wax, vegetable oil wax, animal oil wax, a blend of vegetable oil wax and animal oil wax, or any combination thereof,

[0020] (b) One or more rosin sizing agents including fortified rosin, esterified rosin, rosin wax, resin acid derivatives, gum rosin, wood rosin, tall oil rosin, rosin paste, rosin-based dispersions, or any combination thereof,

[0021] (c) One or more surfactants including nonionic surfactants, anionic surfactants, or a combination thereof, wherein (i) the nonionic surfactant is selected from ethoxylated alcohols including, but not limited to, secondary alcohol ethoxylates, ethoxylated sorbitan esters, sorbitan esters, glycerol esters including, but not limited to, glycerol monostearate (GMS), and any combination thereof, and (ii) the anionic surfactant is selected from fatty alcohol ether sulfates, alkyl ether sulfates, special soaps including, but not limited to, anionic long-chain fatty acids, and any combination thereof,

[0022] (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 saturated hydrocarbon waxes, paraffinic hydrocarbon waxes, isoparaffinic hydrocarbon waxes, naphthenic hydrocarbon waxes, and any mixture thereof,

[0023] (e) optionally comprising one or more long-chain fatty acids having carbon chain lengths in the range of C4-C30, C20-C30, C22-C30, or C24-C30.

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

[0025] (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,

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

[0027] In some exemplary embodiments described above, 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 reinforced rosin sizing,

[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 water, optionally hot water, optionally water at 70-99°C, 75-98°C, 85-95°C, or 90-95°C to the oil phase,

[0042] (c) Heat to 70-99°C, 75-98°C, or 85-95°C, and then emulsify for a time range of 0.5-5 hours, 0.5-4 hours, or 1-3 hours, as selected.

[0043] (d) Homogenization and

[0044] (e) Optionally, the obtained reverse-phase 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 in their final form contain a total solids content ranging from 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.

[0047] In some exemplary embodiments described above,

[0048] (a) The one or more polyhydroxyalkanoates (PHAs) comprises an aqueous polyhydroxyalkanoate (PHA) dispersion containing one or more polyhydroxyalkanoate (PHA) polymers, and the aqueous polyhydroxyalkanoate (PHA) dispersion has a total dry solids content in the range of 10-70% by weight, 40-60% by weight, 45-55% by weight, or 49-51% by weight.

[0049] (b) The one or more rheological modifiers include one or more bio-based gums, including but not limited to hydroxypropyl methylcellulose (HPMC), pre-hydrated cellulose gum, xanthan gum, or mixtures thereof; one or more bio-based hydrocolloids; one or more polyacrylate dispersions, including but 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.

[0050] (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, or

[0051] (d) Any combination of (a), (b), and (c).

[0052] In some exemplary embodiments described above, one or more auxiliary additives include:

[0053] (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.

[0054] (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.

[0055] (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.

[0056] (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.

[0057] In some exemplary embodiments described above,

[0058] (a) The one or more auxiliary additives include clay, nanoclay, microfibrillated cellulose (MFC), microcrystalline cellulose (MCC), cellulose nanocrystals (CNC), or a combination thereof.

[0059] (b) The one or more auxiliary additives include clay, nanoclay, microcrystalline cellulose (MCC), or a combination thereof.

[0060] (c) The one or more auxiliary additives include clay and microcrystalline cellulose (MCC), or

[0061] (d) The one or more auxiliary additives include cellulose nanocrystalline CNC.

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

[0063] (a) one or more biowax emulsions in an amount in the range of 30-90% by weight, 40-90% by weight, 50-90% by weight, 60-90% by weight, or preferably 70-90% by weight,

[0064] (b) One or more polyhydroxyalkanoates (PHAs) in an amount in the range of 10-70% by weight, 10-60% by weight, 10-50% by weight, 10-40% by weight, 10-35% by weight, or preferably 10-30% 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,

[0066] (d) comprising one or more of the auxiliary additives in an amount ranging from 0.1 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.

[0067] In some exemplary embodiments described above, the barrier coating composition comprises a 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 polyhydroxyalkanoates (PHAs) using mechanical mixing to form the 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 bio-based solids in the range of 40–90% by weight, 45–80% by weight, 50–70% by weight, or 55–60% by weight of the total solids content,

[0070] (c) Having particle sizes in the range of 0.2-15 μm, 0.2-15 μm, 0.5-12 μm, 1-10 μm, 2-8 μm, 0.2-5 μm, 1-4 μm, 2-3 μm, or 2.5-3 μm, or

[0071] (d) Any combination of one, two, three, or four of (a) to (c).

[0072] In some exemplary embodiments described above, a barrier coating composition is applied as one or more coatings to a lignocellulose substrate, including, but not limited to, paper, cardboard, lightweight wrapping paper base sheets, fast food wrapping paper base sheets, molded fibers, or 100% recycled linerboard sheets, wherein the one or more coatings are formed at room temperature, 15-30°C, or 20-25°C using a conventional paper coater, roll coater, or metering size press, and subsequently oven-cured for a preferred time, optionally, 60-120 seconds, 70-110 seconds, 80-100 seconds, or 90-95 seconds, at 100-120°C, 105-115°C, or 108-112°C, thereby applying the barrier coating composition to the lignocellulose substrate as follows:

[0073] (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.

[0074] (b) The one or more coatings provide a barrier against the permeation of oil, grease, or water, preferably one or more of oil and / or grease, 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 polyhydroxyalkanoate (PHA) alone.

[0075] (c) When one or more coatings are applied at a coat weight of 1 to 30, 2 to 20, 3 to 10, or 4 to 8 grams (gsm) per square meter, they result in equal or enhanced KIT test values ​​(i.e., measures of oil and grease resistance) and optionally Cobb 1-minute test values ​​(i.e., measures of the mass of water absorbed per square meter over one minute) (i.e., higher KIT values ​​and lower Cobb values) compared to one or more coatings similarly formed from polyhydroxyalkanoate (PHA) alone.

[0076] (d) When one or more coatings are applied at a coat weight of 1 to 30, 2 to 20, 3 to 10, or 4 to 8 grams (gsm) per square meter, the Cobb 1-minute test results show a decrease dependent on the coat weight,

[0077] (e) 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, 50-80% by weight, 50-70% by weight, 50-60% by weight, or 50-55% by weight.

[0078] In another aspect, the present invention provides a barrier coating composition for paper or cardboard, and optionally a method for preparing an oil barrier coating composition using any of the aforementioned compositions, the method comprising

[0079] (a) Forming at least one biowax emulsion,

[0080] (b) Forming or providing one or more polyhydroxyalkanoates (PHAs),

[0081] (c) Dispersing the at least one biowax emulsion in the one or more polyhydroxyalkanoates (PHAs),

[0082] (d) Dispersing one or more rheological modifiers in the one or more polyhydroxyalkanoates (PHAs),

[0083] (e) Dispersing one or more auxiliary additives in the one or more polyhydroxyalkanoates (PHAs),

[0084] Steps (c) to (e) are carried out together or separately.

[0085] In some exemplary embodiments of this method, the at least one biowax emulsion is

[0086] (a) One or more biowaxes comprising 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 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) comprises 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.

[0087] (b) One or more rosin sizing agents, including 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,

[0088] (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,

[0089] (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 saturated hydrocarbon waxes, paraffinic hydrocarbon waxes, isoparaffinic hydrocarbon waxes, naphthenic hydrocarbon waxes, and any mixture thereof,

[0090] (e) optionally comprising one or more long-chain fatty acids having carbon chain lengths in the range of C4-C30, C20-C30, C22-C30, or C24-C30.

[0091] In some exemplary embodiments of this method, the at least one biowax emulsion is

[0092] (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,

[0093] (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,

[0094] (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,

[0095] (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,

[0096] (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,

[0097] The at least one biowax emulsion is

[0098] (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,

[0099] (ii) Adding a certain amount of water, optionally hot water, optionally water at 70-99°C, 75-98°C, 85-95°C, or 90-95°C to the oil phase,

[0100] (iii) Heat to 70-99°C, 75-98°C, or 85-95°C, and then emulsify for a time range of 0.5-5 hours, 0.5-4 hours, or 1-3 hours, as selected.

[0101] (iv) Homogenization and,

[0102] (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.

[0103] (vi) Optionally, the addition of a biocide and comprising a reversed-phase biowax emulsion formed by the above.

[0104] In some exemplary embodiments of this method, the at least one biowax emulsion in its final form contains a total solids content ranging from 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.

[0105] In some exemplary embodiments of this method,

[0106] (a) The one or more polyhydroxyalkanoates (PHAs) comprises an aqueous polyhydroxyalkanoate (PHA) dispersion containing one or more polyhydroxyalkanoate (PHA) polymers, wherein the aqueous polyhydroxyalkanoate (PHA) dispersion has a total dry solids content in the range of 10-70% by weight, 40-60% by weight, 45-55% by weight, or 49-51% by weight.

[0107] (b) The one or more rheological modifiers include one or more bio-based gums, one or more bio-based hydrocolloids, one or more polyacrylate dispersion

[0108] (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.

[0109] Moreover,

[0110] (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.

[0111] (ii) 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.

[0112] (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.

[0113] (iv) 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.

[0114] In some exemplary embodiments of this method, the barrier coating composition is

[0115] (a) an amount of at least one biowax emulsion in the range of 30-90% by weight, 40-90% by weight, 50-90% by weight, 60-90% by weight, or preferably 70-90% by weight,

[0116] (b) One or more polyhydroxyalkanoates (PHAs) in an amount in the range of 10-70% by weight, 10-60% by weight, 10-50% by weight, 10-40% by weight, 10-35% by weight, or preferably 10-30% by weight,

[0117] (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,

[0118] (d) comprising one or more of the auxiliary additives in an amount ranging from 0.1 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,

[0119] The at least one biowax emulsion, the one or more rheological modifiers, and the one or more auxiliary additives are dispersed separately or together in the one or more polyhydroxyalkanoates (PHAs) by mechanical mixing to form the barrier coating composition, and in the final form the barrier coating composition is

[0120] (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,

[0121] (ii) containing a bio-based solids content in the range of 40-90% by weight, 45-80% by weight, 50-70% by weight, or 55-60% by weight of the total solids content,

[0122] (iii) Having particle sizes in the range of 0.2-15 μm, 0.2-15 μm, 0.5-12 μm, 1-10 μm, 2-8 μm, 0.2-5 μm, 1-4 μm, 2-3 μm, or 2.5-3 μm,

[0123] (iv) Any combination of one, two, or three of (i) to (iii).

[0124] 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, lightweight wrapping paper base sheets, fast food wrapping paper base sheets, molded fibers, or 100% recycled linerboard sheets, wherein the one or more coatings are formed at room temperature, 15–30°C, or 20–25°C using a conventional paper coater, roll coater, or metering size press, and subsequently oven-cured for a preferred time, optionally, 60–120 seconds, 70–110 seconds, 80–100 seconds, or 90–95 seconds, at 100–120°C, 105–115°C, or 108–112°C, thereby completing the application of the barrier coating composition to the lignocellulose substrate as follows:

[0125] (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.

[0126] (b) The one or more coatings provide a barrier against the permeation of oil, grease, or water, preferably one or more of oil and / or grease, 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 polyhydroxyalkanoate (PHA) alone.

[0127] (c) When one or more coatings are applied at a coat weight of 1 to 30, 2 to 20, 3 to 10, or 4 to 8 grams (gsm) per square meter, they result in equal or enhanced KIT test values ​​(i.e., measures of oil and grease resistance) and optionally Cobb 1-minute test values ​​(i.e., measures of the mass of water absorbed per square meter over one minute) (i.e., higher KIT values ​​and lower Cobb values) compared to one or more coatings similarly formed from polyhydroxyalkanoate (PHA) alone.

[0128] (d) When one or more of the coatings are applied at a coat weight of 1 to 30, 2 to 20, 3 to 10, or 4 to 8 grams (gsm) per square meter, the Cobb 1-minute test results show a decrease dependent on the coat weight,

[0129] (e) 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, 50-80% by weight, 50-70% by weight, 50-60% by weight, or 50-55% by weight.

[0130] In another embodiment, the present invention provides a lignocellulose substrate comprising one or more coatings of a barrier coating composition made of any of the compositions described above, or produced by any of the methods described above, including, but not limited to, paper, cardboard, lightweight wrapping paper base sheets, fast food wrapping paper, molded fibers, or 100% recycled linerboard sheets.

[0131] In another embodiment, the present invention relates to a sheet product for use as a food service packaging material, a beverage service packaging material, or any packaging material suitable for transporting and / or storing oil, grease and / or water, preferably oil and / or grease,

[0132] (a) A substrate comprising lignocellulose fibers and having a first large parallel surface and a second large parallel surface,

[0133] (b) A coating structure comprising a barrier coating composition of any one of the aforementioned compositions, applied in at least one layer to at least one of the larger surfaces of the substrate,

[0134] The sheet-like product in question is

[0135] (i) KIT test values ​​of 11-12, or 12,

[0136] (ii) optionally, a sheet-like product having a Cobb 1-minute value of less than 6 gsm is provided.

[0137] In another embodiment, the present invention also provides a sheet product for use as a food service packaging material, a beverage service packaging material, or any packaging material suitable for transporting and / or storing materials containing oil, grease, and / or water, preferably oil and / or grease,

[0138] (a) A substrate comprising lignocellulose fibers and having a first large parallel surface and a second large parallel surface,

[0139] (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,

[0140] The sheet-like product in question is

[0141] (i) KIT test values ​​of 11-12, or 12,

[0142] (ii) optionally, a sheet-like product having a Cobb 1-minute value of less than 6 gsm is provided. [Brief explanation of the drawing]

[0143] The present invention will be described in more detail below with reference to the accompanying drawings, which are described in detail below.

[0144] [Figure 1] This provides an exemplary bar graph showing the KIT values ​​indicating the oil resistance and grease resistance of a barrier coating wrapping paper base sheet coated with the double-layer barrier coating according to Example 2.

[0145] [Figure 2] This provides an exemplary bar graph showing the KIT values ​​indicating the oil resistance and grease resistance of a barrier coating wrapping paper base sheet coated with the single-layer barrier coating composition according to Example 3.

[0146] [Figure 3] An exemplary bar graph of Cobb 1-minute values ​​indicating water absorption for a barrier coating wrapping paper base sheet coated with the single-layer barrier coating composition according to Example 3 is provided. [Modes for carrying out the invention]

[0147] 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.

[0148] definition As used herein, the singular forms "a," "and," and "the" refer to multiple objects unless specifically indicated by the context.

[0149] 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.

[0150] 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.

[0151] 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.

[0152] 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. The viscosity of the barrier coating composition may be modified as needed to suit the method used when it is added to or applied to the product / substrate (e.g., paper or cardboard).

[0153] 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.

[0154] 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.

[0155] 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.

[0156] 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.

[0157] 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.

[0158] The term "microcrystalline wax" refers to a type of 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.

[0159] 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.

[0160] The term "polyhydroxyalkanoate (PHA) dispersion" refers to a dispersion of polyhydroxyalkanoate (PHA) or polyhydroxyalkanoate (PHA) copolymer blended or dispersed with various other components of a barrier coating material. In the present invention, the PHA dispersion acts as a material to which a barrier coating material, such as a biowax emulsion, is dispersed or blended to prevent the coating material from penetrating into a paper or cardboard substrate. PHA makes it possible to apply the barrier material or barrier coating composition as a barrier coating to a paper or cardboard substrate without penetrating into the pores of the paper or cardboard. Furthermore, the dispersion of the barrier material in PHA makes it possible to apply the barrier coating to one surface of a sheet-like paper or cardboard substrate without leakage or leaching to the other side.

[0161] 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.

[0162] 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.

[0163] 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.

[0164] 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.

[0165] 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.

[0166] 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.

[0167] 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.

[0168] 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.

[0169] As used herein, “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 thereto such that the biowax composition becomes substantially an aqueous continuous phase and the hydrophobic liquid phase is a dispersed 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 generally, if at least three consecutive measurements are within a standard of measurement error, the solution is considered inverted. 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, an optional 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 then added thereto. 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.

[0170] As used herein, the term “polyhydroxyalkanoate (PHA)” refers to a collection of naturally occurring thermoplastic polyesters produced spontaneously by numerous microorganisms, including those obtained through bacterial fermentation of sugars or lipids. More than 150 different monomers can be combined within this family to obtain materials with extremely diverse properties. Commercially available PHA compositions include poly-(R)-3-hydroxybutyrate (PHB) and poly-(R)-3-hydroxybutyrate-co-(R)-3-hydroxyvalerate (PHBV), which represent only a small fraction of the available property sets for PHAs. Generally, PHA materials contain one or more units of the following formula, for example, between 10 and 1,000,000: -OCR 1 R 2 (CR 3 R 4 ) n CO-,

[0171] In the formula, n is an integer, and R 1 , R 2 , R 3 , and R 4 may independently be a long-chain hydrocarbon radical, a halo-substituted radical and a hydroxy-substituted radical, a hydroxy radical, a halogen radical, a nitrogen-substituted radical, an oxygen-substituted radical, and / or a hydrocarbon radical containing a hydrogen atom. As used herein, the formula -(CR 3 R 4 ) n - is defined to include the following formulas. -CR 3 R 4 - (where n = 1), -CR 3 R 4 CR 3’ R 4’ - (where n = 2), and -CR 3 R 4 CR 3’ R 4’ CR 3’’ R 4’’ - (where n = 3)

[0172] These units can be the same or different units in a polyhydroxyalkanoate homopolymer, such as, for example, a polyhydroxyalkanoate copolymer or a polyhydroxyalkanoate terpolymer. The polymer typically has a molecular weight greater than 300 Da, for example, 300 to 10 8 Da. For the present invention, the polyhydroxyalkanoate is formulated as an aqueous dispersion. However, the polyhydroxyalkanoate can be formulated for use as a solid or liquid polymer, as a polymer mixture, as an aqueous dispersion, as an aqueous suspension, as a reverse emulsion, as an inverse polymer, or by any method known in the art for a specific use.

[0173] As used herein, the term “polyhydroxyalkanoate (PHA) copolymer” refers to a polymer comprising a polyhydroxyalkanoate monomer and one or more comonomers. The comonomers may be anionic, cationic, or nonionic.

[0174] 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.

[0175] 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.

[0176] 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, allyl sulfonate, itaconic acid, acrylamidemethylbutanoic acid, fumaric acid, vinylphosphonic acid, and allylphosphonic acid. Examples include 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, acrylamidopropyltrimonium chloride, salts of the said acid, or other anionic ethylene-based unsaturated compounds.

[0177] 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.

[0178] 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.

[0179] Packaging materials must possess the necessary barrier properties against water, water vapor, gas / air, and grease / oil, depending on their end-use, with the aim of protecting the material from the surrounding environment or preventing 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.

[0180] 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, polyhydroxyalkanoate (PHA) dispersions, and other additives. Barrier coating compositions comprising a biowax emulsion dispersed in one or more polyhydroxyalkanoate (PHA) with one or more 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 of more than 50% in multiple coating layers (renewable raw materials), and (ii) <6 g / m² 2The two-layer coated sheet achieved excellent oil and water barrier properties, including a Cobb value (1 min) and a KIT value of 12.

[0181] 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.

[0182] In exemplary embodiments, auxiliary additives such as clay, nanoclay, cellulose nanocrystals (CNC), 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. Nanocellulose possesses exceptional barrier properties, particularly air resistance and grease / oil resistance. Generally, cellulose nanocrystals (CNCs), produced by acid hydrolysis of cellulose, can be available in spray-dried powder form. The use of CNCs can extend the oil barrier properties of PHA-based barrier coating dispersions.

[0183] Surprisingly, the addition of MCC and nanoclay significantly improved the OGR and water barrier performance of the biowax coating, and CNC further increased the water barrier performance. This proves to be a remarkable method for improving both the bio-content and barrier properties of paper through optimized barrier coating formulations.

[0184] Barrier coating composition and method In one embodiment, the present invention provides a barrier coating composition, optionally an oil barrier coating composition for use on paper or a board substrate, wherein the barrier coating composition is

[0185] (a) one or more biowax emulsions, (b) one or more polyhydroxyalkanoates (PHAs), (c) one or more rheological modifiers, and (d) one or more auxiliary additives.

[0186] In another aspect, the present invention provides a barrier coating composition for paper or cardboard, the barrier coating composition being

[0187] (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 polyhydroxyalkanoates (PHAs); (c) one or more rheological modifiers; and (d) one or more auxiliary additives.

[0188] 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 polyhydroxyalkanoates (PHAs), (c) one or more rheological modifiers, and (d) one or more auxiliary additives, wherein the one or more biowax emulsions

[0189] (i) 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, blends of vegetable oil wax and animal fat wax, or any combination thereof,

[0190] (ii) One or more rosin sizing agents, including 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,

[0191] (iii) 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,

[0192] (iv) 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 any mixture thereof,

[0193] (v) optionally comprising one or more long-chain fatty acids having carbon chain lengths in the range of C4-C30, C20-C30, C22-C30, or C24-C30.

[0194] Biowax Emulsion

[0195] 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.

[0196] In some exemplary embodiments, the one or more biowax emulsions are

[0197] (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,

[0198] (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,

[0199] (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,

[0200] (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 any mixture thereof,

[0201] (e) optionally comprising one or more long-chain fatty acids having carbon chain lengths in the range of C4-C30, C20-C30, C22-C30, or C24-C30.

[0202] 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.

[0203] In some embodiments, one or more biowax emulsions comprise a pre-formed reverse-phase biowax emulsion which comprises (a) combining 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 in a reactor and heating 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 water, optionally (a) adding hot water, or optionally water at 70-99°C, 75-98°C, or 85-95°C to the oil phase; (c) emulsifying at 70-99°C, 75-98°C, or 85-95°C for an optionally long period of time ranging from 0.5-5 hours, 0.5-4 hours, or 1-3 hours; (d) homogenizing; (e) cooling the resulting reverse-phase biowax emulsion to a temperature ranging from 10-35°C, 15-30°C, or 20-25°C; and (f) optionally adding a biocide.

[0204] In some embodiments, one or more biowax emulsions comprise a pre-formulated reverse-phase biowax emulsion, which is separately pre-formulated before being added to the barrier coating composition by dispersing the reverse-phase biowax emulsion in one or more polyhydroxyalkanoates (PHAs), one or more rheological modifiers, and / or one or more auxiliary additives.

[0205] 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 in one or more polyhydroxyalkanoates (PHAs) before, during, or after the addition of rheological modifiers and / or auxiliary additives.

[0206] In some preferred 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 in one or more polyhydroxyalkanoates (PHAs) before the addition of an optional rheological modifier and / or an optional auxiliary additive.

[0207] 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.

[0208] In some embodiments, a pre-formed reverse-phase biowax emulsion is separately pre-formulated and then added to (i) one or more polyhydroxyalkanoates (PHAs), (ii) one or more auxiliary additives, and / or (iii) one or more rheological modifiers, thereby resulting in an improved solids content (e.g., 30-70% by weight) compared to the same barrier coating composition formed without pre-forming one or more biowaxes as a reverse-phase biowax emulsion. A barrier coating composition is formed having a final barrier coating composition with a final barrier coating composition having 40-60% by weight, 45-55% by weight, or 48-52% by weight, an improved bio-based solids content (e.g., 40-90% by weight, 45-80% by weight, 50-70% by weight, or 55-60% by weight), and / or an improved particle size (e.g., 0.2-15 μm, 0.2-15 μm, 0.5-12 μm, 1-10 μm, 2-8 μm, 0.2-5 μm, 1-4 μm, 2-3 μm, or 2.5-3 μm).

[0209] In some exemplary embodiments, the one or more biowaxes are

[0210] (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.

[0211] In some exemplary embodiments described above, in the one or more biowax emulsions,

[0212] (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.

[0213] In some exemplary embodiments described above, the one or more biowax emulsions are

[0214] (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.

[0215] In some exemplary embodiments described above, the one or more biowax emulsions are

[0216] (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,

[0217] (b) Adding a certain amount of water, optionally hot water, optionally water at 70-99°C, 75-98°C, 85-95°C, or 90-95°C to the oil phase,

[0218] (c) Heat to 70-99°C, 75-98°C, or 85-95°C, and then emulsify for a time range of 0.5-5 hours, 0.5-4 hours, or 1-3 hours, as selected.

[0219] (d) Homogenization and

[0220] (e) Optionally, the obtained reverse-phase 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.

[0221] (f) Optionally, the addition of a biocide and the inverse phase biowax emulsion formed by the addition of the biocide.

[0222] In some exemplary embodiments described above, the one or more biowax emulsions in their final form contain a total solids content ranging from 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.

[0223] In some embodiments, the one or more biowax emulsions have a final bulk viscosity in the range of 1000-2400 cPs, 1400-1800 cPs, 1500-1700 cPs, 1550-1650 cPs, or 1590-1610 cPs.

[0224] Polyhydroxyalkanoate (PHA)

[0225] In some exemplary embodiments described above, the one or more polyhydroxyalkanoates (PHAs) comprises an aqueous polyhydroxyalkanoate (PHA) dispersion containing one or more polyhydroxyalkanoate (PHA) polymers, wherein the aqueous polyhydroxyalkanoate (PHA) dispersion has a total dry solids content in the range of 10-70% by weight, 40-60% by weight, 45-55% by weight, or 49-51% by weight.

[0226] In some exemplary embodiments, the barrier coating composition comprises one or more polyhydroxyalkanoates (PHAs) in amounts ranging from 10 to 70% by weight, 10 to 60% by weight, 10 to 50% by weight, 10 to 40% by weight, 10 to 35% by weight, or preferably 10 to 30% by weight.

[0227] In some exemplary embodiments, the one or more biowax emulsions, rheological modifiers, and auxiliary additives are dispersed directly in the one or more polyhydroxyalkanoates (PHAs), either together or separately, in any order, to form a barrier coating composition.

[0228] Rheological modifier

[0229] In some exemplary embodiments of any of the above, the one or more rheological modifiers include one or more bio-based gums, including but not limited to hydroxypropyl methylcellulose (HPMC), pre-hydrated cellulose gum, xanthan gum, or mixtures thereof; one or more bio-based hydrocolloids; one or more polyacrylate dispersions, including but 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.

[0230] In some preferred embodiments, the one or more rheological modifiers include hydroxypropyl methylcellulose (HPMC), 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.

[0231] 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. In some embodiments, the amount of the one or more rheological modifiers is modified to achieve a final bulk viscosity of 40 to 2000 cPs or 150 to 800 cPs for the barrier coating composition.

[0232] In some exemplary embodiments, the one or more rheological modifiers are directly dispersed in the barrier coating composition before, during, or after the addition of the biowax emulsion, polyhydroxyalkanoate (PHA), and / or auxiliary additives. In some exemplary embodiments, the one or more rheological modifiers are separately or directly dispersed in the one or more polyhydroxyalkanoate (PHA) together with the biowax emulsion and / or auxiliary additives.

[0233] Auxiliary additives

[0234] 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.

[0235] In some exemplary embodiments of any of the above, (a) the one or more auxiliary additives include clay, nanoclay, microfibrillated cellulose (MFC), microcrystalline cellulose (MCC), cellulose nanocrystals (CNC), or a combination thereof; (b) the one or more auxiliary additives include clay, nanoclay, microcrystalline cellulose (MCC), or a combination thereof; (c) the one or more auxiliary additives include clay and microcrystalline cellulose MCC; or (d) the one or more auxiliary additives include cellulose nanocrystals CNC.

[0236] In preferred embodiments, the one or more auxiliary additives include clay, nanoclay, microcrystalline cellulose (MCC), cellulose nanocrystals (CNC), or a combination thereof.

[0237] 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.

[0238] 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, polyhydroxyalkanoate (PHA), and / or rheological modifier. In some exemplary embodiments, the one or more auxiliary additives are dispersed separately or together with the biowax emulsion and / or rheological modifier directly in the one or more polyacrylate carrier.

[0239] In some exemplary embodiments described above, the barrier coating composition

[0240] (a) one or more biowax emulsions in an amount ranging from 30 to 90% by weight, 40 to 90% by weight, 50 to 90% by weight, 60 to 90% by weight, or preferably 70 to 90% by weight; (b) one or more polyhydroxyalkanoates (PHAs) in an amount ranging from 10 to 70% by weight, 10 to 60% by weight, 10 to 50% by weight, 10 to 40% by weight, 10 to 35% by weight, or preferably 10 to 30% 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; and (d) one or more auxiliary additives in an amount ranging from 0.1 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.

[0241] In some exemplary embodiments described above, the barrier coating composition comprises a 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 polyhydroxyalkanoates (PHAs) using mechanical mixing to form the dispersion, wherein the barrier coating composition in its final form is

[0242] (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 40–90% by weight, 45–80% by weight, 50–70% by weight, or 55–60% by weight of the total solids content; (c) having particle sizes in the range of 0.2–15 μm, 0.2–15 μm, 0.5–12 μm, 1–10 μm, 2–8 μm, 0.2–5 μm, 1–4 μm, 2–3 μm, or 2.5–3 μm; or (d) any combination of one, two, or three of (a) to (c).

[0243] In some embodiments, the barrier coating composition, in its final form, has a bulk viscosity in the range of 40-2000 cPs, 100-800 cPs, 150-650 cPs, or 200-400 cPs, and is stable for more than 3 months at 25°C.

[0244] Barrier coating In some exemplary embodiments of any of the foregoing, a barrier coating composition, when applied as one or more coatings to a lignocellulose substrate, including but not limited to paper, cardboard, lightweight wrapping paper base sheets, fast food wrapping paper base sheets, molded fibers, or 100% recycled linerboard sheets, is formed at room temperature, 15-30°C, or 20-25°C using a conventional paper coater, roll coater, or metering size press, and subsequently oven-cured for a preferred time, optionally, 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 so on:

[0245] (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.

[0246] (b) The one or more coatings provide a barrier against the permeation of oil, grease, or water, preferably one or more of oil and / or grease, 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 polyhydroxyalkanoate (PHA) alone.

[0247] (c) When one or more coatings are applied at a coat weight of 1 to 30, 2 to 20, 3 to 10, or 4 to 8 grams (gsm) per square meter, they result in equal or enhanced KIT test values ​​(i.e., measures of oil and grease resistance) and optionally Cobb 1-minute test values ​​(i.e., measures of the mass of water absorbed per square meter over one minute) (i.e., higher KIT values ​​and lower Cobb values) compared to one or more coatings similarly formed from polyhydroxyalkanoate (PHA) alone.

[0248] (d) When one or more coatings are applied at a coat weight of 1 to 30, 2 to 20, 3 to 10, or 4 to 8 grams (gsm) per square meter, the Cobb 1-minute test results show a decrease dependent on the coat weight,

[0249] (e) 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, 50-80% by weight, 50-70% by weight, 50-60% by weight, or 50-55% by weight.

[0250] Method for preparing a barrier coating composition In another aspect, the present invention provides a barrier coating composition for paper or cardboard, and optionally a method for preparing an oil barrier coating composition using any of the aforementioned compositions, the method comprising

[0251] (a) Forming at least one biowax emulsion, preferably an inverted phase emulsion,

[0252] (b) Forming or providing one or more polyhydroxyalkanoates (PHAs),

[0253] (c) Dispersing the at least one biowax emulsion in the one or more polyhydroxyalkanoates (PHAs),

[0254] (d) Dispersing one or more rheological modifiers in the one or more polyhydroxyalkanoates (PHAs),

[0255] (e) Dispersing one or more auxiliary additives in the one or more polyhydroxyalkanoates (PHAs),

[0256] Steps (c) to (e) are carried out together or separately.

[0257] 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

[0258] (a) Forming at least one biowax emulsion, preferably an inverted-phase biowax emulsion,

[0259] (b) Dispersing the reversed-phase biowax emulsion in one or more polyhydroxyalkanoates (PHAs),

[0260] (c) Dispersing one or more rheological modifiers in one or more polyhydroxyalkanoates (PHAs),

[0261] (d) Dispersing one or more auxiliary additives in the one or more polyhydroxyalkanoates (PHAs),

[0262] 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.

[0263] In some exemplary embodiments of this method, the at least one biowax emulsion is

[0264] (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) comprises 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.

[0265] (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,

[0266] (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,

[0267] (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 any mixture thereof,

[0268] (e) optionally comprising one or more long-chain fatty acids having carbon chain lengths in the range of C4-C30, C20-C30, C22-C30, or C24-C30.

[0269] In some exemplary embodiments of this method, the at least one biowax emulsion is

[0270] (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.

[0271] The at least one biowax emulsion is

[0272] (ii) 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 a temperature in the range of 70-99°C, 75-98°C, 85-95°C, or 90-95°C to form an oil phase; (ii) adding a certain amount of water, optionally hot water, optionally water at 70-99°C, 75-98°C, or 85-95°C to the oil phase; and (iii) 70-9 The invention comprises a reverse-phase biowax emulsion formed by (iv) heating to 9°C, 75-98°C, or 85-95°C, then optionally emulsifying for a time range of 0.5-5 hours, 0.5-4 hours, or 1-3 hours, (iv) homogenizing, (v) optionally cooling the resulting reverse-phase biowax emulsion to a temperature range of 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.

[0273] In some exemplary embodiments of this method, the at least one biowax emulsion in its final form contains a total solids content ranging from 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.

[0274] In some embodiments of this method, the at least one biowax emulsion has a final bulk viscosity in the range of 1400-1800 cPs, 1500-1700 cPs, 1550-1650 cPs, or 1590-1610 cPs.

[0275] In some exemplary embodiments of this method,

[0276] (a) The one or more polyhydroxyalkanoates (PHAs) comprises an aqueous polyhydroxyalkanoate (PHA) dispersion containing one or more polyhydroxyalkanoate (PHA) polymers, wherein the aqueous polyhydroxyalkanoate (PHA) dispersion has a total dry solids content in the range of 10-70% by weight, 40-60% by weight, 45-55% by weight, or 49-51% by weight.

[0277] (b) The one or more rheological modifiers include one or more bio-based gums, one or more bio-based hydrocolloids, one or more polyacrylate dispersion

[0278] (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.

[0279] Moreover,

[0280] (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.

[0281] (ii) Before the cellulose nanocrystal (CNC) is dispersed in the barrier coating composition, it is formulated as an aqueous slurry or spray-dried powder, and optionally, it is produced by acid hydrolysis of cellulose,

[0282] (iii) The microfibrillated cellulose (MFC) has (i) an average particle length in the range of 20 - 200 μm, 50 - 200 μm, 100 - 200 μm, or 150 - 200 μm, (ii) 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) before being formulated with the barrier coating composition, it is formulated as an aqueous solution having a dry content of 10 - 30 wt%, 15 - 25 wt%, or 18 - 22 wt%.

[0283] (iv) The microcrystalline cellulose (MCC) has (i) an average particle diameter in the range of 1 - 8 μm, 2 - 7 μm, 3 - 6 μm, or 4 - 5 μm, and (ii) before being dispersed in the barrier coating composition, it is formulated as an aqueous slurry or spray-dried powder.

[0284] In some embodiments of this method, the barrier coating composition

[0285] contains (a) the at least one biowax emulsion in an amount in the range of 30 - 90 wt%, 40 - 90 wt%, 50 - 90 wt%, 60 - 90 wt%, or preferably 70 - 90 wt%, (b) the one or more polyhydroxyalkanoates (PHA) in an amount in the range of 10 - 70 wt%, 10 - 60 wt%, 10 - 50 wt%, 10 - 40 wt%, 10 - 35 wt%, or preferably 10 - 30 wt%, (c) the one or more rheology modifiers in an amount in the range of 0.1 - 5 wt%, 0.1 - 4 wt%, or 0.1 - 3 wt%, and (d) the one or more auxiliary additives in an amount in the range of 0.1 - 10 wt%, 1 - 9 wt%, 1 - 8 wt%, 1 - 6 wt%, or 1 - 3 wt%.

[0286] The at least one biowax emulsion, the one or more rheological modifiers, and the one or more auxiliary additives are dispersed separately or together in the one or more polyhydroxyalkanoates (PHAs) by mechanical mixing to form the barrier coating composition, and in the final form the barrier coating composition has (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, (ii) a bio-based solids content in the range of 40-90% by weight, 45-80% by weight, 50-70% by weight, or 55-60% by weight of the total solids content, or (iii) a particle size in the range of 0.2-15 μm, 0.2-15 μm, 0.5-12 μm, 1-10 μm, 2-8 μm, 0.2-5 μm, 1-4 μm, 2-3 μm, or 2.5-3 μm, or

[0287] (iv) Any combination of one, two, or three of (i) to (iii).

[0288] In some embodiments of this method, the dose of one or more rheological modifiers is modified to achieve a final bulk viscosity of the barrier coating composition of 40-2000 cPs or 150-800 cPs. In some embodiments of this method, the barrier coating composition has a bulk viscosity in the range of 40-2000 cPs, 100-700 cPs, 150-650 cPs, or 200-400 cPs. In some embodiments of this method, the barrier coating composition comprises a stable dispersion having stability for more than 3 months at 25°C.

[0289] 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, lightweight wrapping paper base sheets, fast food wrapping paper base sheets, molded fibers, or 100% recycled linerboard sheets, wherein the one or more coatings are formed at room temperature, 15–30°C, or 20–25°C using a conventional paper coater, roll coater, or metering size press, and subsequently oven-cured for a preferred time, optionally, 60–120 seconds, 70–110 seconds, 80–100 seconds, or 90–95 seconds, at 100–120°C, 105–115°C, or 108–112°C, thereby completing the application of the barrier coating composition to the lignocellulose substrate as follows:

[0290] (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.

[0291] (b) The one or more coatings provide a barrier against the permeation of oil, grease, or water, preferably one or more of oil and / or grease, 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 polyhydroxyalkanoate (PHA) alone.

[0292] (c) When one or more coatings are applied at a coat weight of 1 to 30, 2 to 20, 3 to 10, or 4 to 8 grams (gsm) per square meter, they result in equal or enhanced KIT test values ​​(i.e., measures of oil and grease resistance) and optionally Cobb 1-minute test values ​​(i.e., measures of the mass of water absorbed per square meter over one minute) (i.e., higher KIT values ​​and lower Cobb values) compared to one or more coatings similarly formed from polyhydroxyalkanoate (PHA) alone.

[0293] (d) When one or more of the coatings are applied at a coat weight of 1 to 30, 2 to 20, 3 to 10, or 4 to 8 grams (gsm) per square meter, the Cobb 1-minute test results show a decrease dependent on the coat weight,

[0294] (e) 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, 50-80% by weight, 50-70% by weight, 50-60% by weight, or 50-55% by weight.

[0295] In another embodiment, the present invention provides a lignocellulose substrate comprising one or more coatings of a barrier coating composition made of any of the compositions described above, or produced by any of the methods described above, including, but not limited to, paper, cardboard, lightweight wrapping paper base sheets, fast food wrapping paper, molded fibers, or 100% recycled linerboard sheets.

[0296] In another embodiment, the present invention relates to a sheet product for use as a food service packaging material, a beverage service packaging material, or any packaging material suitable for transporting and / or storing oil, grease and / or water, preferably oil and / or grease,

[0297] 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 one 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 (ii) optionally a Cobb 1-minute value of less than 6 gsm.

[0298] In another embodiment, the present invention also provides a sheet product for use as a food service packaging material, a beverage service packaging material, or any packaging material suitable for transporting and / or storing materials containing oil, grease, and / or water, preferably oil and / or grease,

[0299] 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 prepared by any one of the aforementioned methods, 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 (ii) optionally a Cobb 1-minute value of less than 6 gsm.

[0300] The methods and compositions disclosed herein as examples may be practiced in the absence of any elements not specifically disclosed herein and / or any elements specifically disclosed herein. Exemplary embodiments of the present invention and their advantages are further disclosed in the following examples. [Examples]

[0301] The examples provided herein are for illustrative purposes only, so that the invention may be better understood. These examples should not be construed as limiting the invention in any way.

[0302] Example 1: Preparation of a barrier coating composition A barrier coating composition was prepared for evaluation as a coating for paper or cardboard.

[0303] Bio-wax emulsion

[0304]

Table 1

[0305] *Non-ionic surfactants: ethoxylated alcohols and esters; Anionic surfactants: fatty alcohol ether sulfates, alkyl ether sulfates, special soaps

[0306] 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 emulsion, which was then cooled using a rapid cooling process.

[0307] The components according to 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 emulsion, to which a certain amount of hot water was 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. Then, a biocide was added.

[0308] Rapid cooling was achieved by cooling the resulting reverse emulsion to a temperature in the range of 15 - 25 °C using an ice bath, a cooling jacket, or a cooling core.

[0309] The final bio-wax emulsion BE1 obtained had a bulk viscosity of 1600 cPs and a total solids of 56%.

[0310] Barrier coating composition (BCC)

[0311]

Table 2

[0312] Barrier coating compositions (BCC1-BCC8) were prepared by combining a high-solids biowax emulsion (BE1), a bio-based rheological modifier, and auxiliary additives, as shown in Table 2, with a polyhydroxyalkanoate (PHA) support used as a control. Barrier coating compositions BCC1-BCC3 contained a rheological modifier but no auxiliary additives, BCC4 contained a rheological modifier and one auxiliary additive and achieved very good oil barrier properties, and BCC5-BCC7 contained one auxiliary additive. BCC9 contained two rheological modifiers and two auxiliary additives and achieved a target KIT value of 12. BCC9 was the most stable dispersion and has good rheological properties for paper coating applications.

[0313] PHA dispersions are commercially available and are a fully bio-based alternative to polyethylene (PE) for producing renewable barrier-coated paper and cardboard products from renewable sources. PHA itself is used as a coating for paper or cardboard products such as coffee cups to prevent moisture and water from leaking from the cup material. A 100% PHA coating dispersion provides paper with an excellent barrier against water and moisture, but offers unacceptable oil resistance.

[0314] The barrier coating composition of the present invention was formed by directly dispersing the components shown in Table 2 in a PHA dispersion to form a stable biowax barrier coating dispersion having a final bulk viscosity generally in the range of 150 to 600 cPs. The biowax dosage level was in the range of 30 to 60% by weight of the total dry coating solids.

[0315] A dispersion of polyacrylate was used as rheology modifier 1. Hydroxypropyl methylcellulose (HPMC) (rheology modifier 2 in Table 2) belongs to the group of cellulose ethers in which a hydroxyl group is substituted with one or more of the three hydroxyl groups present on the cellulose ring. HPMC is a spray-dried powder and is directly dispersed in the barrier coating composition.

[0316] MCCs having an average particle size in the range of 3 to 6 μm were incorporated as spray-dried powder before being dispersed in the barrier coating composition.

[0317] Where indicated, beet microfibrillated cellulose (MFC) produced by Atrex from parenchyma cellulose (not wood) was added. The MFC was formulated as an aqueous solution having (i) a dry content of 20% by weight, (ii) an average particle length of less than 200 μm, (iii) an average particle width of less than 1 μm, and (iv) a dry content of 10-30% by weight before being dispersed in the barrier coating composition.

[0318] 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.

[0319] Where indicated, microcrystalline cellulose (MCC) having the ability to provide barrier-enhancing properties was added. Before being dispersed in the barrier coating composition, MCC having an average particle size in the range of 3 to 6 μm was incorporated as a spray-dried powder.

[0320] Results: The resulting barrier coating composition (i) contains >50% by weight of total coating solids and total renewable materials, with a maximum of 85% by weight of bio and natural content; (ii) has a shelf life of at least 3 months; and (iii) has good coating rheological properties suitable for conventional paper coaters under ambient temperature conditions.

[0321] Stability testing was performed by aging the biowax barrier coating dispersion at 25°C for 3 months. The bulk viscosity of the coating dispersion slowly increased to a stable maximum value. If the aged dispersion formed a gel within 3 months, the sample was considered unstable.

[0322] These results provide the first proof of concept that a barrier coating composition dispersion can be provided by dispersing a biowax emulsion in a PHA dispersion, exhibiting high stability (>3 months), high total solids content (>50%), and a high proportion (up to 90% by weight) of solids from bio-based contents (i.e., sustainable and renewable sources). The bulk viscosity was suitable for use in either a conventional paper coater or a metering size press at room temperature.

[0323] Example 2: Evaluation of barrier coatings for lightweight wrapping paper The base material for barrier coatings has a basic weight of 36g / m². 2 (gsm), Cobb 1 minute = 45gsm, and HAVI lightweight wrapping paper base sheet with no surface size.

[0324] Barrier coating compositions (PHA control and BCC1-3) were applied to a base sheet by roller coating, followed by oven curing 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. The average total coat weight was 12 gsm.

[0325] KIT tests were performed to measure the oil and grease resistance (OGR) levels of barrier-coated sheets. KIT test values ​​generally range from 1 to 12, where 1 indicates no OGR barrier and 12 indicates very good OGR. The KIT test results are shown in Figure 1.

[0326] These results demonstrate that the control PHA coating dispersion required a double coating application to achieve complete coating coverage on the paper surface; however, even with a double coating application, the control PHA coating dispersion still failed to achieve the target KIT value of 12. Barrier coating compositions BCC1-BCC3, containing 10-30% by weight of biowax emulsion dispersed in the PHA dispersion, achieved higher KIT values, demonstrating improved oil and grease resistance.

[0327] These results provide the first proof of the concept that the barrier coating composition of the present invention can be effectively used as a natural and bio-based barrier coating for the manufacture of food wrapping paper having improved OGR with PHA alone.

[0328] Example 3: Evaluation of auxiliary additives in barrier coatings for lightweight wrapping paper The substrate for the barrier coating is described in Example 2.

[0329] Barrier coating compositions (control and BCC4-7) were applied to lightweight wrapping paper base sheets by roller coating, followed by oven curing at 110°C for 90 seconds. A single coating of each barrier coating composition was applied to a single side of the base sheet. The average total coat weight was 6 gsm.

[0330] KIT tests were performed to measure the oil and grease resistance (OGR) levels of barrier-coated sheets. The KIT test results are shown in Figure 2. For control, BCC6, and BCC7 coated sheets, a Cobb 1-minute test was performed to measure g / m² over a given time (e.g., 1 minute). 2 The mass of water that can be absorbed by the surface of the barrier-coated sheet was determined in gsm units. The results of the Cobb 1-minute test are shown in Figure 3. BCC7 and BCC8 (data not shown) were the best barrier coating formulations for OGR wrapping paper applications and were able to achieve a KIT value of 12.

[0331] These results demonstrate that the control PHA coating dispersion exhibited insufficient oil resistance due to incomplete coating coverage on the paper surface resulting from a single coating application. Coatings BCC4 (PHA + 50% biowax + 2% MFC) and BCC5 (PHA + 50% biowax + 2% MCC) yielded significantly better KIT values ​​than PHA alone, indicating that the addition of MCC and nanoclay at low dose levels further enhanced the oil resistance of the biowax / PHA formulations.

[0332] The BCC6 (PHA + 50% biowax + 3% CNC) and BCC7 (PHA + 60% biowax + 2% MCC + 5% clay) coatings achieved complete coating coverage on the paper surface with a single coating application, resulting in a KIT value of 12, a dramatic increase compared to PHA alone. The BCC6 and BCC7 coatings provided significantly better water resistance than PHA, with BCC6 yielding the best Cobb 1-minute results.

[0333] 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 transporting and / or storing materials containing oil, water, and / or grease, in a low coat weight range of 6-8 gsm.

Claims

1. A barrier coating composition, optionally an oil barrier coating composition for use on a paper or cardboard substrate, (a) One or more biowax emulsions, (b) One or more polyhydroxyalkanoates (PHAs) (c) One or more rheological modifiers, (d) A barrier coating composition comprising one or more auxiliary additives.

2. The one or more biowax emulsions described above (a) 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, (b) One or more rosin sizing agents, including 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, (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, comprising saturated hydrocarbon waxes, paraffinic hydrocarbon waxes, isoparaffinic hydrocarbon waxes, naphthenic hydrocarbon waxes, and any mixture thereof, (e) The barrier coating composition according to claim 1, comprising, optionally, one or more long-chain fatty acids having carbon chain lengths in the range of C4-C30, C20-C30, C22-C30, or C24-C30.

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 / or (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. One or more of the biowax emulsions in the barrier coating are: (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, and / or (e) The barrier coating composition according to claim 1, 2, or 3, wherein one or more long-chain fatty acids include at least one having a carbon chain length in the range of C22 to C30.

5. One or more of the biowax emulsions in the barrier coating are: (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 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 of the above-mentioned 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 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, and / or (e) The barrier coating composition according to any one of the prior claims, comprising, optionally, 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.

6. The one or more biowax emulsions in the barrier coating (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 water, optionally hot water, optionally water at 70-99°C, 75-98°C, 85-95°C, or 90-95°C to the oil phase, (c) Heat to 70-99°C, 75-98°C, or 85-95°C, and then emulsify for a time range of 0.5-5 hours, 0.5-4 hours, or 1-3 hours, as selected. (d) Homogenization and (e) Optionally, the obtained reverse-phase 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 barrier coating composition according to any one of the prior claims, wherein one or more of the biowax emulsions in the barrier coating contain, in the final form, 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 the total solids content is bio-based.

8. (a) The one or more polyhydroxyalkanoates (PHAs) comprises an aqueous polyhydroxyalkanoate (PHA) dispersion containing one or more polyhydroxyalkanoate (PHA) polymers, wherein the aqueous polyhydroxyalkanoate (PHA) dispersion has a total dry solids content in the range of 10 to 70% by weight, 40 to 60% by weight, 45 to 55% by weight, or 49 to 51% by weight. (b) The one or more rheological modifiers include one or more bio-based gums, including but not limited to hydroxypropyl methylcellulose (HPMC), pre-hydrated cellulose gum, xanthan gum, or mixtures thereof; one or more bio-based hydrocolloids; one or more polyacrylate dispersions, including but 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. (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, or (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 auxiliary additives include clay, nanoclay, microfibrillated cellulose (MFC), microcrystalline cellulose (MCC), cellulose nanocrystals (CNC), or a combination thereof. (b) The one or more auxiliary additives include clay, nanoclay, microcrystalline cellulose (MCC), or a combination thereof. (c) The one or more auxiliary additives include clay and microcrystalline cellulose (MCC), or (d) The barrier coating composition according to any one of the prior claims, wherein the one or more auxiliary additives comprises cellulose nanocrystalline CNC.

11. The barrier coating composition is as follows: (a) one or more of the biowax emulsions in an amount in the range of 30-90% by weight, 40-90% by weight, 50-90% by weight, 60-90% by weight, or preferably 70-90% by weight, (b) One or more of the above in an amount in the range of 10-70% by weight, 10-60% by weight, 10-50% by weight, 10-40% by weight, 10-35% by weight, or preferably 10-30% by weight, (c) One or more of the rheological modifiers in an amount in the range of 0.1 to 5% by weight, 0.1 to 4% by weight, or 0.1 to 3% by weight, (d) The barrier coating composition according to any one of the prior claims, comprising one, two, three, or all of the above-mentioned auxiliary additives in an amount ranging from 0.1 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.

12. The barrier coating composition comprises a dispersion formed by mechanically mixing to disperse one or more biowax emulsions, one or more rheological modifiers, and one or more auxiliary additives separately or together in one or more polyhydroxyalkanoates (PHAs), wherein the barrier coating composition, in its final form, (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 40-90% by weight, 45-80% by weight, 50-70% by weight, or 55-60% by weight of the total solids content, (c) Having particle sizes in the range of 0.2 to 15 μm, 0.2 to 15 μm, 0.5 to 12 μm, 1 to 10 μm, 2 to 8 μm, 0.2 to 5 μm, 1 to 4 μm, 2 to 3 μm, or 2.5 to 3 μm, or (d) A barrier coating composition according to any one of the prior claims, wherein one, two, or all of (a) to (c).

13. When applied as one or more coatings to a lignocellulose substrate, including but not limited to paper, cardboard, lightweight wrapping paper base sheets, fast food wrapping paper base sheets, molded fibers, or 100% recycled linerboard sheets, the one or more coatings are formed at room temperature, 15–30°C, or 20–25°C using a conventional paper coater, roll coater, or metering size press, and subsequently oven-cured at 100–120°C, 105–115°C, or 108–112°C, the application of the barrier coating composition to the lignocellulose substrate 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 a barrier against the permeation of oil, grease, or water, preferably one or more of oil and / or grease, to 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 similarly formed from the polyhydroxyalkanoate (PHA) alone. (c) When one or more coatings are applied in a coating weight of 1 to 30, 2 to 20, 3 to 10, or 4 to 8 grams (gsm) per square meter, they result in equal or enhanced KIT test values ​​(i.e., measures of oil and grease resistance) and optionally Cobb 1-minute test values ​​(i.e., measures of the mass of water absorbed per square meter over one minute) (i.e., higher KIT values ​​and lower Cobb values) compared to one or more coatings similarly formed from polyhydroxyalkanoate (PHA) alone. (d) When one or more coatings are applied at a coat weight of 1 to 30, 2 to 20, 3 to 10, or 4 to 8 grams (gsm) per square meter, the Cobb 1-minute test results show a decrease dependent on the coat weight, and / or (e) 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 bio-based material percentages: ≥ 50% by weight, 50-80% by weight, 50-70% by weight, 50-60% by weight, or 50-55% by weight.

14. A barrier coating composition for paper or cardboard, optionally a method for preparing an oil barrier coating composition 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 polyhydroxyalkanoates (PHAs), (c) Dispersing the at least one biowax emulsion in the one or more polyhydroxyalkanoates (PHAs), (d) Dispersing one or more rheological modifiers in the one or more polyhydroxyalkanoates (PHAs), (e) Dispersing one or more auxiliary additives in the one or more polyhydroxyalkanoates (PHAs), 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 comprising palm oil wax, castor oil wax, soybean oil wax, fish oil wax, tallow oil wax, vegetable oil wax, animal oil wax, a blend 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) 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 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, (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, comprising saturated hydrocarbon waxes, paraffinic hydrocarbon waxes, isoparaffinic hydrocarbon waxes, naphthenic hydrocarbon waxes, and any mixture thereof, (e) The method according to claim 14, comprising, optionally, one or more long-chain fatty acids having carbon chain lengths in the range of C4-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 water, optionally hot water, optionally water at 70-99°C, 75-98°C, 85-95°C, or 90-95°C to the oil phase, (iii) Heat to 70-99°C, 75-98°C, or 85-95°C, and then emulsify for a time range of 0.5-5 hours, 0.5-4 hours, or 1-3 hours, as selected. (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 method according to any one of claims 14, 15, or 16, wherein the at least one biowax emulsion in its final form 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 the total solids content is a biobase.

18. (a) The one or more polyhydroxyalkanoates (PHAs) comprises an aqueous polyhydroxyalkanoate (PHA) dispersion containing one or more polyhydroxyalkanoate (PHA) polymers, wherein the aqueous polyhydroxyalkanoate (PHA) dispersion has a total dry solids content in the range of 10 to 70% by weight, 40 to 60% by weight, 45 to 55% by weight, or 49 to 51% by weight. (b) The one or more rheological modifiers include one or more bio-based gums, one or more bio-based hydrocolloids, one or more polyacrylate dispersion (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. (ii) 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. (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. The method according to any one of claims 14, 15, 16, or 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.

19. The barrier coating composition is (a) an amount of at least one biowax emulsion in the range of 30-90% by weight, 40-90% by weight, 50-90% by weight, 60-90% by weight, or preferably 70-90% by weight, (b) One or more of the above in an amount in the range of 10-70% by weight, 10-60% by weight, 10-50% by weight, 10-40% by weight, 10-35% by weight, or preferably 10-30% by weight, (c) One or more of the rheological modifiers in an amount in the range of 0.1 to 5% by weight, 0.1 to 4% by weight, or 0.1 to 3% by weight, (d) comprising one or more of the above-mentioned auxiliary additives in an amount in the range of 0.1 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, The at least one biowax emulsion, the one or more rheological modifiers, and the one or more auxiliary additives are dispersed separately or together in the one or more polyhydroxyalkanoates (PHAs) by mechanical mixing to form the barrier coating composition, and in the final form the barrier coating composition is (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 40-90% by weight, 45-80% by weight, 50-70% by weight, or 55-60% by weight of the total solid content, (iii) Having particle sizes in the range of 0.2-15 μm, 0.2-15 μm, 0.5-12 μm, 1-10 μm, 2-8 μm, 0.2-5 μm, 1-4 μm, 2-3 μm, or 2.5-3 μm, or The method according to any one of claims 14, 15, 16, or 17, which is any combination of one, two, or three of (iv)(i) to (iii).

20. The barrier coating composition is applied as one or more coatings to a lignocellulose substrate, including, but not limited to, paper, cardboard, lightweight wrapping paper base sheets, fast food wrapping paper, molded fibers, or 100% recycled linerboard sheets, wherein the one or more coatings are formed at room temperature, 15-30°C, or 20-25°C using a conventional paper coater, roll coater, or metering size press, and subsequently oven-cured at 100-120°C, 105-115°C, or 108-112°C, and the application of the barrier coating composition to the lignocellulose substrate 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 a barrier against the permeation of oil, grease, or water, preferably one or more of oil and / or grease, to 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 similarly formed from the polyhydroxyalkanoate (PHA) alone. (c) When one or more coatings are applied in a coating weight of 1 to 30, 2 to 20, 3 to 10, or 4 to 8 grams (gsm) per square meter, they result in equal or enhanced KIT test values ​​(i.e., measures of oil and grease resistance) and optionally Cobb 1-minute test values ​​(i.e., measures of the mass of water absorbed per square meter over one minute) (i.e., higher KIT values ​​and lower Cobb values) compared to one or more coatings similarly formed from polyhydroxyalkanoate (PHA) alone. (d) When one or more of the coatings are applied at a coat weight of 1 to 30, 2 to 20, 3 to 10, or 4 to 8 grams (gsm) per square meter, the Cobb 1-minute test results show a decrease dependent on the coat weight, (e) 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, 50-80% by weight, 50-70% by weight, 50-60% by weight, or 50-55% by weight.

21. A lignocellulose substrate comprising one or more coatings of the barrier coating composition described in any one of claims 1 to 13, or produced by the method described in any one of claims 14 to 20, including, but not limited to, paper, cardboard, lightweight wrapping paper base sheets, fast food wrapping paper, molded fibers, or 100% recycled linerboard sheets.

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, grease, and / or water, preferably oil 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, (ii) Optionally, a sheet-like product having a Cobb 1-minute value of less than 6 gsm.

23. 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, grease, and / or water, preferably oil 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, (ii) Optionally, a sheet-like product having a Cobb 1-minute value of less than 6 gsm.

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