COMPOSIÇÃO DE REVESTIMENTO POR DISPERSÃO DE PHA E SUBSTRATO A BASE DE FIBRA REVESTIDO

Abstract

The present invention relates to a dispersion coating composition for coating of a fiber-based substrate, said dispersion coating composition comprising, in a liquid medium: 50-99 wt% of PHA (polyhydroxyalkanoate) particles, based on the total solid content of the dispersion coating composition, and 1-50 wt% of low molecular weight polyol dispersant, based on the total solid content of the dispersion coating composition, wherein the dispersion coating composition has a total solid content in the range of 20-80 wt%. The present invention further relates to a fiber-based substrate coated with such a dispersion coating composition and to a packaging container comprising such a dispersion coated fiber-based substrate.

Description

[0001] The present disclosure relates to methods for preparing coated fiber-based substrates, specifically paper or cardboard coated with polyhydroxyalkanoate (PHA), for use as packaging materials. BACKGROUND

[0002] Coating fiber-based substrates, such as paper and cardboard, with plastics is often used to combine the mechanical properties of the fiber-based substrate with the barrier and sealing properties of a plastic film. Paper or cardboard provided with a relatively small amount of a suitable plastic material can provide the properties needed to make the paper or cardboard suitable for many demanding applications, for example, as cardboard for liquid or food packaging.

[0003] In addition to a liquid barrier inside the packaging, fiber-based packaging products, such as cups or trays, intended especially for packaging cold products, should normally also be provided with a condensation layer on the outside of the packaging. This condensation layer prevents condensate from softening the bulky fiber-based substrate. The packaging product is normally provided with at least one heat-sealable liquid barrier inside.

[0004] In food or liquid packaging, extrusion-coated polyolefin coatings are frequently used as barrier layers. Petition 870250083635, dated 09 / 17 / 2025, page 7 / 53 2 / 37 liquids, heat-seal layers, and adhesives. However, recycling this type of polymer-coated board is not easy, as it is difficult to separate the polymers from the fibers.

[0005] In the prior art, attempts were made to replace extrusion-coated polyolefin coatings with more environmentally friendly and / or more easily recyclable solutions, but so far without real success. In many cases, some, but not all, of the properties of extrusion-coated polyolefin coatings are obtained by alternative solutions.

[0006] Dispersion barrier coatings for paper and cardboard are an interesting alternative to extrusion coating for improving the repulpability and recyclability of barrier-coated fiber-based substrates. Dispersion coating is especially useful as it can be implemented online on paper or cardboard machines. Many dispersions or emulsions, such as styrene / acrylate or styrene / butadiene emulsions, however, are not biodegradable or compostable.

[0007] On the other hand, dispersion-based coating barriers based on polyhydroxyalkanoates (PHAs) are compostable and biodegradable. The challenge with PHA dispersions is finding a suitable composition that allows for good workability and coating coverage (retention) and good barrier performance. Coating coverage and subsequent barrier performance are highly dependent on substrate roughness and layer weight, with heavier layers negatively impacting recyclability, drying efficiency, and cost. PHA dispersions Petition 870250083635, dated 09 / 17 / 2025, p. 8 / 53 3 / 37 are generally stabilized with surfactants and / or surfactant polymers, which can cause uneven barrier quality due to dispersant migration or a greater tendency to foam. The tendency to foam can create even more problems during recycling and repulping or disintegration of the coated web.

[0008] Many of the problems mentioned above can be avoided by applying PHA using melt extrusion coating. However, unfortunately, melt extrusion coating of PHA cannot be implemented online on large-scale paper or cardboard machines. Furthermore, melt extrusion coating generally requires relatively high coating weights and leads to lower adhesion compared to dispersion-coated grades, and melt extrusion-coated grades are more difficult to repulp than dispersion-coated grades.

[0009] Therefore, there is still a need for improved solutions to replace conventional plastic coatings, especially polyolefin coatings, in paper and cardboard-based packaging materials, while maintaining acceptable liquid barrier properties. At the same time, there is a need for liquid barrier layers for fiber-based substrates, such as paper or cardboard substrates, that facilitate the repulping and recycling of used packaging materials, compared to packaging laminates that use conventional plastic films. DESCRIPTION OF THE INVENTION

[0010] One objective of the present disclosure is to provide an alternative to plastic films commonly used as barrier layers, to provide barrier properties. Petition 870250083635, dated 09 / 17 / 2025, page 9 / 53 4 / 37 to liquids in paper or cardboard-based packaging materials, such as liquid or food packaging.

[0011] Another objective of the present disclosure is to provide a liquid barrier layer for a paper or cardboard-based packaging material, such as a carton for packaging liquids or food, which is based on renewable raw materials.

[0012] Another objective of the present disclosure is to provide a liquid barrier layer for a paper or cardboard-based packaging material, such as a carton for packaging liquids or food, that facilitates the repulping of the packaging material, compared to packaging laminates that use conventional plastic films.

[0013] Another objective of the present disclosure is to provide an enhanced PHA coating dispersion that overcomes or improves upon at least some of the problems associated with previous PHA coating dispersions.

[0014] The aforementioned objectives, as well as other objectives that will be achieved by those skilled in the art in light of the present revelation, are attained by the various aspects of the present revelation.

[0015] The present invention is based on the understanding that the problems associated with dispersion coating of PHA dispersions on fiber-based substrates can be overcome by using a relatively high amount of a low molecular weight polyol as a dispersant for the PHA particles. A surprising observation is that high amounts of a low molecular weight polyol do not negatively affect the barrier properties of the PHA coating. Typically, the Petition 870250083635, dated 09 / 17 / 2025, page 10 / 53 5 / 37 dispersants are used in amounts less than 1% by weight, as dispersants would be expected to deteriorate the barrier properties of the PHA coating.

[0016] According to a first aspect illustrated in this document, a dispersion coating composition is provided for coating a fiber-based substrate, said dispersion coating composition comprising, in a liquid medium:

[0017] Fifty to ninety-nine percent by weight of PHA (polyhydroxyalkanoate) particles, based on the total solids content of the dispersion coating composition, and

[0018] One to fifty percent by weight of low molecular weight polyol dispersant, based on the total solids content of the dispersion coating composition, wherein the dispersion coating composition has a total solids content in the range of 20-80% by weight.

[0019] PHA particles are preferably the main component of the dispersion coating composition, based on the dry weight of the composition. In some embodiments, the dispersion coating composition comprises at least 50% by weight, at least 65% by weight, at least 70% by weight, or at least 90% by weight of PHA particles, based on the total solids content of the dispersion coating composition. In some embodiments, the dispersion coating composition comprises 70-99% by weight, preferably 90-99% by weight of PHA particles based on the total solids content of the dispersion coating composition. In some embodiments, the dispersion coating composition comprises 50-97% Petition 870250083635, dated 09 / 17 / 2025, page 11 / 53 6 / 37 by weight, 50-95% by weight, 50-92.5% by weight, 50-90% by weight, 50-87.5% by weight, or 50-85% by weight of PHA particles based on the total solids content of the dispersion coating composition. In some embodiments, the dispersion coating composition comprises 65-97% by weight, 65-95% by weight, 65-92.5% by weight, 65-90% by weight, 65-87.5% by weight, or 65-85% by weight of PHA particles based on the total solids content of the dispersion coating composition. In some embodiments, the dispersion coating composition comprises 70-97% by weight, 70-95% by weight, 70-92.5% by weight, 70-90% by weight, 70-87.5% by weight, or 70-85% by weight of PHA particles based on the total solids content of the dispersion coating composition. In some embodiments, the dispersion coating composition comprises 90-97% by weight, 90-95% by weight, or 90-92.5% by weight of PHA particles based on the total solids content of the dispersion coating composition.

[0020] The particle size distribution of PHA can be multimodal or unimodal. In some embodiments, PHA particles have a unimodal or bimodal particle size distribution. In some embodiments, PHA particles have a unimodal particle size distribution.

[0021] In some embodiments, the PHA particles have an average particle size (D50) below 15 μm, preferably below 12 μm and more preferably in the range of 0.5-11 μm or in the range of 0.8-8 μm.

[0022] In some embodiments, the dispersion coating composition is free or substantially free of particles or particle agglomerates, with Petition 870250083635, dated 09 / 17 / 2025, page 12 / 53 7 / 37 particle size above 50 μm, above 20 μm or above 15 μm.

[0023] Unless otherwise indicated, all particle sizes and particle size distributions described herein are determined by a laser diffraction method using a Mastersizer 3000 in accordance with ISO 13320:2009.

[0024] In some embodiments, the PHA particles comprise PHA in an amount of 70-99.9% by weight, preferably in an amount of 90-99.9% by weight, based on the dry weight of the PHA particles.

[0025] In some embodiments, the PHA is selected from the group consisting of poly(3-hydroxyoctanoate) (PHO), poly(3-hydroxydecanoate) (PHD), poly(3-hydroxyhexanoate) (PHH) and poly(3-hydroxyvalerate) (PHV), poly(3-hydroxybutyrate—co-3-hydroxyvalerate) (PHBV), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH), poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P3HB4HB), poly(3-hydroxyoctanoate-co-3-hydroxyhexanoate) (PHOHH), poly(3-hydroxyoctanoate-co-3-hydroxydecanoate) (PHOHD) and poly(3-hydroxyoctanoate-co-3-hydroxydodecanoate) (PHDHDD) or a combination thereof. Those skilled in the art understand that the PHA suitable for use in dispersion coating compositions is not limited to those listed in this document.

[0026] In some embodiments, PHA is a copolymer of PHA.

[0027] In some embodiments, PHA is selected from the group consisting of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH), poly(3-hydroxybutyrate-co-4 Petition 870250083635, dated 09 / 17 / 2025, page 13 / 53 8 / 37 hydroxybutyrate) (P3HB4HB), poly(3-hydroxyoctanoate-co-3-hydroxyhexanoate) (PHOHH), poly(3-hydroxyoctanoate-co-3-hydroxydecanoate) (PHOHD) and poly(3-hydroxyoctanoate-co-3-hydroxydodecanoate) (PHDHDD), or a combination thereof. Those skilled in the art understand that PHA copolymers suitable for use in dispersion coating compositions are not limited to those listed herein.

[0028] In some embodiments, the PHA is a medium-chain length PHA, preferably a PHA with 614 carbon atoms per monomeric unit.

[0029] The type of PHA suitable for use in dispersion coating composition can be characterized by its melting point. In some embodiments, the PHA has a melting point in the range of 100-170°C, preferably in the range of 120-160°C. Unless otherwise indicated, the melting points mentioned herein are determined by differential scanning calorimetry in accordance with ASTM D3418.

[0030] PHA for use in dispersion coating composition is preferably biodegradable and compostable.

[0031] The dispersion coating composition of the invention comprises 1 to 50% by weight of low molecular weight polyol dispersant, based on the total solids content of the dispersion coating composition. Dispersants are generally low molecular weight polymers used to improve the colloidal stability of a dispersion and reduce viscosity (due to less floc formation, etc.). Dispersants typically do not Petition 870250083635, dated 09 / 17 / 2025, page 14 / 53 9 / 37 are used to improve the barrier properties of a coating. In fact, many dispersants, especially at higher concentrations, are expected to migrate and deteriorate the barrier properties of a barrier coating.

[0032] In some embodiments, the dispersion coating composition comprises 3-35% by weight, and more preferably 5-30% by weight, of the low molecular weight polyol dispersant, based on the total solids content of the dispersion coating composition. In some embodiments, the dispersion coating composition comprises 7.5-35% by weight, preferably 10-35% by weight, more preferably 12.5-35% by weight and more preferably 15-35% by weight of the low molecular weight polyol dispersant, based on the total solids content of the dispersion coating composition. In some embodiments, the dispersion coating composition comprises 7.5-30% by weight, preferably 10-30% by weight, more preferably 12.5-30% by weight and more preferably 15-30% by weight of the low molecular weight polyol dispersant, based on the total solids content of the dispersion coating composition.In some embodiments, the dispersion coating composition comprises 7.5-25% by weight, preferably 10-25% by weight, more preferably 12.5-25% by weight, and most preferably 15-25% by weight of the low molecular weight polyol dispersant, based on the total solids content of the dispersion coating composition.

[0033] In some embodiments, the dispersion coating composition comprises 3-35% by weight of Petition 870250083635, dated 09 / 17 / 2025, page 15 / 53 10 / 37 low molecular weight polyol dispersant and 65-97% by weight of PHA particles, or 5-30% by weight of low molecular weight polyol dispersant and 70-95% by weight of PHA particles, based on the total solids content of the dispersion coating composition. In some embodiments, the dispersion coating composition comprises 7.5-30% by weight of low molecular weight polyol dispersant and 70-92.5% by weight of PHA particles, or 10-30% by weight of low molecular weight polyol dispersant and 70-90% by weight of PHA particles, or 12.5-30% by weight of low molecular weight polyol dispersant and 70-87.5% by weight of PHA particles, or 15-30% by weight of low molecular weight polyol dispersant and 70-85% by weight of PHA particles, based on the total solids content of the dispersion coating composition.

[0034] In some embodiments, the low molecular weight polyol dispersant has a molecular weight in the range of 50-2000 g / mol, preferably in the range of 50-1500 g / mol and, more preferably, in the range of 50-1000 g / mol or in the range of 50-500 g / mol.

[0035] In some embodiments, the low molecular weight polyol dispersant is selected from the group consisting of low molecular weight polysaccharides and sugar alcohols and combinations thereof.

[0036] In some embodiments, the low molecular weight polyol dispersant is selected from the group consisting of low molecular weight polysaccharides with a degree of polymerization (DP) in the range of 2-100, preferably in the range of 2-50. In some embodiments, the low molecular weight polyol dispersant is selected Petition 870250083635, dated 09 / 17 / 2025, page 16 / 53 11 / 37 of the group consists of low molecular weight polysaccharides with a degree of polymerization (DP) in the range of 2 to 12. Low molecular weight polysaccharides can be charged, uncharged, amphoteric, or a combination thereof. Low molecular weight polysaccharides can be linear or branched.

[0037] In some embodiments, the low molecular weight polyol dispersant is a sugar alcohol, preferably a sugar alcohol selected from the group consisting of sorbitol, maltitol, xylitol, mannitol and glycerol, and combinations thereof. In some embodiments, the low molecular weight polyol dispersant is selected from the group consisting of sorbitol, maltitol, xylitol, mannitol and combinations thereof. In some embodiments, the low molecular weight polyol dispersant is sorbitol.

[0038] In some embodiments, the dispersion coating composition further comprises 0.01-15% by weight, preferably in the range of 0.01-10% by weight, and more preferably in the range of 0.1-5% by weight, of a rheology modifier, based on the total solids content of the dispersion coating composition. The rheology modifier is used to adjust the viscosity and water retention of the dispersion coating composition so that it is suitable for application by the preferred application method.

[0039] In some embodiments, the rheology modifier comprises a polymer selected from the group consisting of polysaccharides, polysaccharide derivatives, polypeptides, polypeptide derivatives, or a combination thereof. Petition 870250083635, dated 09 / 17 / 2025, page 17 / 53 12 / 37

[0040] In some embodiments, the dispersion coating composition further comprises 1-30% by weight of filler particles, based on the total solids content of the dispersion coating composition. Too many filler particles can cause cracking and deterioration of barrier properties. The amount of filler particles is preferably 5-25% by weight, and more preferably 5-15% by weight, based on the total solids content of the dispersion coating composition.

[0041] In some embodiments, the filler particles are selected from the group consisting of clay (such as kaolin or calcined kaolin), talc, CaCO3 (such as PCC or GCC), TiO2, Al2O3, SiO2, bentonite, fibers, phyllosilicates, or a combination thereof. The filler particles are preferably high aspect ratio filler particles, for example, flaky particles with an average particle size (D90) below 2 μm.

[0042] In some embodiments, the dispersion coating composition comprises at least 50% by weight of PHA (polyhydroxyalkanoate) particles, the low molecular weight polyol dispersant in the amounts disclosed herein, optionally a rheology modifier in the amounts disclosed herein, and optionally filler particles in the amounts disclosed herein, based on the total solids content of the dispersion coating composition. In some embodiments, the dispersion coating composition comprises at least 70% by weight of PHA (polyhydroxyalkanoate) particles, 7.5-30% by weight of the low molecular weight polyol dispersant, 0.1-5% by weight of the modifier of Petition 870250083635, dated 09 / 17 / 2025, page 18 / 53 13 / 37 rheology and, optionally, 5-25% by weight of filler particles, based on the total solids content of the dispersion coating composition.

[0043] In some embodiments, the composition of the dispersion coating may also comprise other additives, such as lubricants, wetting agents or softeners, bonding agents, dehydration accelerators, moisture control agents, moisture resistance agents, pH adjusting agents, antifoaming agents, crosslinkers, biocides, preservatives and / or colorants.

[0044] In some embodiments, the dispersion coating composition is free of added foaming agents, such as polymeric or non-polymeric surfactants. In some embodiments, the dispersion coating composition comprises less than 0.5% by weight, preferably less than 0.1% by weight, more preferably less than 0.01% by weight, of added foaming agents, such as polymeric or non-polymeric surfactants.

[0045] In some embodiments, the dispersion coating composition is deaerated. Low molecular weight polyol dispersant is advantageous in this respect, as a low molecular weight polyol dispersant is less prone to trapping gas bubbles than a high molecular weight dispersant. Thus, in some embodiments, the dispersion coating composition is preferably free, or substantially free, of air bubbles and other gases.

[0046] In some embodiments, the dispersion coating composition has a total solids content of Petition 870250083635, dated 09 / 17 / 2025, page 19 / 53 14 / 37 range of 30-70% by weight, preferably in the 40-60% by weight range.

[0047] In some embodiments, the dispersion coating composition has a viscosity in the range of 50-4000 MPas, preferably in the range of 250-3500 MPas, determined in accordance with SCAN-P50:84 using a Brookfield viscometer with an LV-4 shaft at a rotational speed of 100 rpm.

[0048] In some embodiments, the dispersion coating composition has an AAGWR water retention value (Abo Akademi water retention value) of less than 250 g / m2, preferably less than 200 g / m2 and more preferably in the range of 50-150 g / m2, determined in accordance with TAPPI T701 μm-0.

[0049] The liquid medium may comprise water, an organic solvent, or a mixture of water and an organic solvent. In some embodiments, the liquid medium is water.

[0050] The dispersion coating composition according to the first aspect described in this document allows the preparation of an improved PHA-coated fiber-based substrate.

[0051] According to a second aspect illustrated in this document, a dispersion-coated fiber-based substrate is provided, comprising:

[0052] a fiber-based substrate having a primary surface and a secondary surface, a dispersion coating layer comprising:

[0053] Fifty to ninety-nine percent by weight of PHA (polyhydroxyalkanoate) particles, based on Petition 870250083635, dated 09 / 17 / 2025, page 20 / 53 15 / 37 total solids content of the coating layer by dispersion, and

[0054] One to fifty percent by weight of low molecular weight polyol dispersant, based on the total solids content of the dispersion coating layer, on the first main surface.

[0055] The fiber-based substrate (also referred to herein as “the substrate”) is preferably a sheet or web of material consisting mainly of wood pulp or other fibrous substances. In some embodiments, the fiber-based substrate is paper or cardboard, preferably cardboard.

[0056] Paper generally refers to a material manufactured in sheets or rolls from wood pulp or other fibrous substances comprising cellulose fibers, used, for example, for writing, drawing or printing, or as packaging material. Paper may be bleached or unbleached and produced in various thicknesses depending on end-use requirements.

[0057] Cardboard generally refers to thick, sturdy paper or cardboard made of cellulose fibers, used, for example, as flat substrates, trays, boxes and / or other types of packaging. Cardboard can be bleached or unbleached and produced in various thicknesses, depending on the end-use requirements.

[0058] In some embodiments, the fiber-based substrate is composed of two or more cellulose-based layers. Each of the cellulose-based layers may have a specific composition of cellulose fibers, such as bleached and / or unbleached Kraft cellulose, sulfite cellulose, Petition 870250083635, dated 09 / 17 / 2025, page 21 / 53 16 / 37 Dissolving pulp, thermomechanical pulp (TMP), chemothermomechanical pulp (CTMP), pressurized milled wood (PGW), high-temperature CTMP (HT-CTMP), waste, recycled fiber, including pre- and post-consumer waste, and / or mixtures thereof. The different layers may have different weights and / or thicknesses and may contain different amounts of additives, such as internal bonding agents.

[0059] As an example, the fiber-based substrate may consist of an upper layer composed of bleached or unbleached Kraft pulp, an intermediate layer composed of a mixture of bleached or unbleached Kraft pulp and CTMP, and a lower layer composed of bleached or unbleached Kraft pulp, wherein the intermediate layer has a greater thickness and / or lower density than the upper and lower layers, respectively.

[0060] A preferred fiber-based substrate is a paper or cardboard with a high content of unbleached fibers, such as at least 50% by weight in at least one of the layers, thus forming a rough surface but with good mechanical performance and a natural appearance.

[0061] In some embodiments, the basis weight of the fiber-based substrate is in the range of 20-800 g / m2. In some embodiments, the fiber-based substrate has a basis weight of at least 100 g / m2. In some embodiments, the fiber-based substrate has a basis weight of at least 150 g / m2, 200 g / m2, 250 g / m2, 300 g / m2, 350 g / m2 or 400 g / m2. The basis weight of the fiber-based substrate is preferably less than 1,000 g / m2, 800 g / m2 or 600 g / m2. Unless otherwise indicated, the basis weight is determined in accordance with ISO 536. Petition 870250083635, dated 09 / 17 / 2025, p. 22 / 53 17 / 37

[0062] The fiber-based substrate can also be surface-bonded or impregnated. In some embodiments, the fiber-based substrate is surface-bonded or impregnated on one or both sides with a surface-bonding composition, preferably comprising a starch derivative, a cellulose derivative, or polyvinyl alcohol (PVOH), or a combination thereof. The starch derivative may be, for example, a slightly modified starch, such as oxidized or cationized starch. The cellulose derivative may be, for example, a sodium carboxymethylcellulose with a degree of substitution greater than 0.4, as in the range of 0.5-1.5. PVOH can be totally or partially hydrolyzed. The surface bonding composition may also comprise a hydrophobic bonding agent such as alkyl ketene dimer (AKD), alkenyl succinic anhydride (ASA), or a rosin bonding agent. The fiber-based substrate is preferably surface bonded or impregnated onto the first primary surface to be subjected to dispersion coating. Surface bonding or impregnation can provide a more uniform and less water-absorbent surface for the dispersion coating composition. Surface bonding or impregnation can also facilitate the release of the PHA coating structure from the fiber-based substrate during repulping.

[0063] In some embodiments, the basis weight of the surface bonding composition is 0.2-10 g / m2, preferably 0.4-8 g / m2 and more preferably 0.8-5 g / m2 per side, based on dry weight.

[0064] The fiber-based substrate itself, prior to PHA coating, may have permeability Petition 870250083635, dated 09 / 17 / 2025, p. 23 / 53 18 / 37 is relatively high for liquids such as water, oil and grease, water vapor and gases such as oxygen, air and carbon dioxide.

[0065] In some embodiments, the fiber-based substrate has a water vapor transmission rate (WVTR), measured in accordance with ASTM F1249 - 20 to 50% relative humidity and 23°C, of ​​at least 200 g / m2 / 24h. In some embodiments, the fiber-based substrate has a COBB60 value measured in accordance with ISO 535:2014 of less than 100 g / m2, preferably less than 80 g / m2, less than 60 g / m2 or less than 40 g / m2.

[0066] The fiber-based substrate itself, prior to PHA coating, preferably has an L&W (15°) flexural strength of at least 145 mN (MD), as determined in accordance with ISO 2493-1.

[0067] PHA particles are preferably the main ingredient of the dispersion coating layer based on the total solids content of the dispersion coating layer. In some embodiments, the dispersion coating layer comprises at least 50% by weight, at least 65% by weight, at least 70% by weight, or at least 90% by weight of PHA particles, based on the total solids content of the dispersion coating layer. In some embodiments, the dispersion coating layer comprises 70-99% by weight, preferably 90-99% by weight, of PHA particles, based on the total solids content of the dispersion coating layer. In some embodiments, the dispersion coating layer comprises 50-97% by weight, 50-95% by weight, 50-92.5% by weight, 50-90% by weight, 50-87.5% by weight or 50-85% by weight of PHA particles, based on the total solids content of the coating layer. Petition 870250083635, dated 09 / 17 / 2025, page 24 / 53 19 / 37 dispersion. In some embodiments, the dispersion coating layer comprises 65-97% by weight, 65-95% by weight, 65-92.5% by weight, 65-90% by weight, 65-87.5% by weight, or 65-85% by weight of PHA particles, based on the total solids content of the dispersion coating layer. In some embodiments, the dispersion coating layer comprises 70-97% by weight, 70-95% by weight, 70-92.5% by weight, 70-90% by weight, 70-87.5% by weight, or 70-85% by weight of PHA particles based on the total solids content of the dispersion coating layer. In some embodiments, the dispersion coating layer comprises 90-97% by weight, 90-95% by weight, or 90-92.5% by weight of PHA particles, based on the total solids content of the dispersion coating layer.

[0068] The particle size distribution of PHA can be multimodal or unimodal. In some embodiments, PHA particles have a unimodal or bimodal particle size distribution. In some embodiments, PHA particles have a unimodal particle size distribution.

[0069] In some embodiments, the PHA particles have an average particle size (D50) below 15 μm, preferably below 12 μm and more preferably in the range of 0.5-11 μm or in the range of 0.8-8 μm.

[0070] In some embodiments, the dispersion coating layer is free or substantially free of particles or particle agglomerates with a particle size above 50 μm, above 20 μm or above 15 μm. Petition 870250083635, dated 09 / 17 / 2025, p. 25 / 53 20 / 37

[0071] In some embodiments, the PHA particles comprise PHA in an amount of 70-99.9% by weight, preferably in an amount of 90-99.9% by weight, based on the dry weight of the PHA particles.

[0072] In some embodiments, the PHA is selected from the group consisting of poly(3-hydroxyoctanoate) (PHO), poly(3-hydroxydecanoate) (PHD), polyhydroxyhexanoate) (PHH) and poly(3-hydroxyvalerate) (PHV), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH), poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P3HB4HB), poly(3-hydroxyoctanoate-co-3-hydroxyhexanoate) (PHOHH), poly(3-hydroxyoctanoate-co-3-hydroxydecanoate) (PHOHD) and poly(3-hydroxyoctanoate-co-3-hydroxydodecanoate) (PHDHDD), or a combination thereof.

[0073] In some embodiments, PHA is a copolymer of PHA.

[0074] In some embodiments, the PHA is selected from the group consisting of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH), poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P3HB4HB), poly(3-hydroxyoctanoate-co-3-hydroxyhexanoate) (PHOHH), poly(3-hydroxyoctanoate-co-3-hydroxydecanoate) (PHOHD) and poly(3-hydroxyoctanoate-co-3-hydroxydodecanoate) (PHDHDD), or a combination thereof.

[0075] In some embodiments, the PHA is a medium-chain length PHA, preferably a PHA with 614 carbon atoms per monomeric unit.

[0076] In some forms, PHA has a melting point in the range of 100-170°C, preferably in the range of 120-160°C. Petition 870250083635, dated 09 / 17 / 2025, page 26 / 53 21 / 37

[0077] In some embodiments, the dispersion coating layer comprises 3-35% by weight, and more preferably 5-30% by weight, of the low molecular weight polyol dispersant, based on the total solids content of the dispersion coating layer. In some embodiments, the dispersion coating layer comprises 7.5-35% by weight, preferably 10-35% by weight, more preferably 12.5-35% by weight and more preferably 15-35% by weight of the low molecular weight polyol dispersant, based on the total solids content of the dispersion coating layer. In some embodiments, the dispersion coating layer comprises 7.5-30% by weight, preferably 10-30% by weight, more preferably 12.5-30% by weight and more preferably 15-30% by weight of the low molecular weight polyol dispersant, based on the total solids content of the dispersion coating layer.In some embodiments, the dispersion coating layer comprises 7.5-25% by weight, preferably 10-25% by weight, more preferably 12.5-25% by weight, and most preferably 15-25% by weight of the low molecular weight polyol dispersant, based on the total solids content of the dispersion coating layer.

[0078] In some embodiments, the dispersion coating layer comprises 3-35% by weight of low molecular weight polyol dispersant and 65-97% by weight of PHA particles, or 5-30% by weight of low molecular weight polyol dispersant and 70-95% by weight of PHA particles, based on the total solids content of the dispersion coating layer. In some embodiments, the dispersion coating layer comprises 7.5-30% in Petition 870250083635, dated 09 / 17 / 2025, page 27 / 53 22 / 37 by weight of low molecular weight polyol dispersant and 70-92.5% by weight of PHA particles, or 10-30% by weight of low molecular weight polyol dispersant and 70-90% by weight of PHA particles, or 12.5-30% by weight of low molecular weight polyol dispersant and 70-87.5% by weight of PHA particles, or 15-30% by weight of low molecular weight polyol dispersant and 70-85% by weight of PHA particles, based on the total solids content of the coating layer by dispersion.

[0079] In some embodiments, the low molecular weight polyol dispersant has a molecular weight in the range of 50-2000 g / mol, preferably in the range of 50-1500 g / mol and, more preferably, in the range of 50-1000 g / mol or in the range of 50-500 g / mol.

[0080] In some embodiments, the low molecular weight polyol dispersant is selected from the group consisting of low molecular weight polysaccharides and sugar alcohols and combinations thereof.

[0081] In some embodiments, the low molecular weight polyol dispersant is selected from the group consisting of low molecular weight polysaccharides with a degree of polymerization (DP) in the range of 2-100, preferably in the range of 2-50. In some embodiments, the low molecular weight polyol dispersant is selected from the group consisting of low molecular weight polysaccharides with a degree of polymerization (DP) in the range of 2 to 12. The low molecular weight polysaccharides may be charged, uncharged, amphoteric, or a combination thereof. The low molecular weight polysaccharides may be linear or branched. Petition 870250083635, dated 09 / 17 / 2025, page 28 / 53 23 / 37

[0082] In some embodiments, the low molecular weight polyol dispersant is a sugar alcohol, preferably a sugar alcohol selected from the group consisting of sorbitol, maltitol, xylitol, mannitol and glycerol, and combinations thereof. In some embodiments, the low molecular weight polyol dispersant is selected from the group consisting of sorbitol, maltitol, xylitol, mannitol and combinations thereof. In some embodiments, the low molecular weight polyol dispersant is sorbitol.

[0083] In some embodiments, the dispersion-coated fiber-based substrate further comprises 0.01-15% by weight, preferably in the range of 0.01-10% by weight, and more preferably in the range of 0.1-5% by weight, of a rheology modifier, based on the total solids content of the dispersion coating layer.

[0084] In some embodiments, the rheology modifier comprises a polymer selected from the group consisting of polysaccharides, polysaccharide derivatives, polypeptides, polypeptide derivatives, or a combination thereof.

[0085] In some embodiments, the dispersion-coated fiber-based substrate further comprises 1-30% by weight of filler particles, based on the total solids content of the dispersion coating layer.

[0086] In some embodiments, the filler particles are selected from the group consisting of clay, talc, CaCO3, TiO2, Al2O3, S1O2, bentonite, fibers, phyllosilicates or a combination thereof.

[0087] In some embodiments, the dispersion coating layer comprises at least 50% by weight. Petition 870250083635, dated 09 / 17 / 2025, page 29 / 53 24 / 37 of PHA (polyhydroxyalkanoate) particles, the low molecular weight polyol dispersant in the amounts disclosed herein, optionally a rheology modifier in the amounts disclosed herein, and optionally filler particles in the amounts disclosed herein, based on the total solids content of the dispersion coating layer. In some embodiments, the dispersion coating layer comprises at least 70% by weight of PHA (polyhydroxyalkanoate) particles, 7.5-30% by weight of the low molecular weight polyol dispersant, 0.1-5% by weight of the rheology modifier, and optionally 5-25% by weight of filler particles, based on the total solids content of the dispersion coating layer.

[0088] In some embodiments, the dispersion coating layer is free of added foaming agents, such as polymeric or non-polymeric surfactants. In some embodiments, the dispersion coating layer comprises less than 0.5% by weight, preferably less than 0.1% by weight, more preferably less than 0.01% by weight, of added foaming agents, such as polymeric or non-polymeric surfactants.

[0089] In some embodiments, the dispersion coating layer is air-free. Thus, in some embodiments, the dispersion coating layer is preferably free of, or substantially free of, air bubbles and other gases.

[0090] In some embodiments, the dispersion coating layer has a basis weight in the range of 540 g / m2, preferably in the range of 5-30 g / m2 and more Petition 870250083635, dated 09 / 17 / 2025, page 30 / 53 25 / 37 preferably in the range of 5-20 g / m2. In some embodiments, the dispersion coating layer has a thickness in the range of 8-20 μm.

[0091] In some embodiments, the dispersion-coated fiber-based substrate has a flexural strength L&W (15°) of at least 145 mN (MD), as determined in accordance with ISO 2493-1.

[0092] In some embodiments, the dispersion-coated fiber-based substrate further comprises a heat-sealable liquid barrier layer on the second main surface.

[0093] In some embodiments, it may be preferable to coat both main surfaces of the fiber-based substrate with the PHA dispersion coating. Thus, in some embodiments, the dispersion-coated fiber-based substrate further comprises a dispersion coating layer comprising:

[0094] Fifty to ninety-nine percent by weight of PHA (polyhydroxyalkanoate) particles, based on the total solids content of the dispersion coating layer, and

[0095] 1 to 50% by weight of low molecular weight polyol dispersant, based on the total solids content of the dispersion coating layer, on the second main surface.

[0096] The dispersion coating layer on the second main surface can also be defined as the dispersion coating layer on the first main surface. The dispersion coating layer on the second main surface may be identical to or different from the layer Petition 870250083635, dated 09 / 17 / 2025, page 31 / 53 26 / 37 of dispersion coating on the first main surface.

[0097] In some embodiments, the dispersion-coated fiber-based substrate has a water vapor transmission rate (WVTR), measured according to the ASTM F1249 standard - 20 to 50% relative humidity and 23°C, of ​​less than 25 g / m2 / 24h, preferably less than 20 g / m2 / 24h and more preferably less than 17 g / m2 / 24h.

[0098] In some embodiments, the first dispersion-coated primary surface of the dispersion-coated fiber-based substrate has a COBB600 value, measured according to ISO 535:2014, of less than 25 g / m2, preferably less than 20 g / m2 and more preferably less than 15 g / m2.

[0099] In some embodiments, the first dispersion-coated primary surface of the dispersion-coated fiber-based substrate has a KIT value of at least 5, preferably at least 10, measured in accordance with the TAPPI T 559 standard.

[00100] In some embodiments, the first main surface coated by dispersion of the dispersion-coated fiber-based substrate does not have holes. The number of holes can be determined, for example, by optical inspection according to the EN13676:2001 standard. The substrate film preferably comprises less than 10 holes / m2, preferably less than 8 holes / m2 and more preferably less than 2 holes / m2, measured according to the EN13676:2001 standard.

[00101] The dispersion-coated fiber-based substrate can be recycled into other paper products. Petition 870250083635, dated 09 / 17 / 2025, page 32 / 53 27 / 37 using common repulping technology. In repulping, the cellulose fibers of the fiber-based substrate are separated from a non-repulpable fraction, called rejects. The rejects may comprise, for example, agglomerated fibers and extraneous solid materials, which need to be removed for disposal or conversion into energy. In some embodiments, the dispersion-coated fiber-based substrate has a repulpability characterized by a rejection rate, as determined according to the PTS RH 021 / 97 test method for Category II products, below 20%, preferably below 10%, more preferably below 5%. The dispersion-coated fiber-based substrate therefore provides very good repulpability. The dispersion-coated fiber-based substrate can therefore be termed repulpable material.

[00102] In some embodiments, the dispersion-coated fiber-based substrate is biodegradable and compostable according to EN 13432.

[00103] According to a third aspect illustrated in this document, a method is provided for manufacturing a dispersion-coated fiber-based substrate, said method comprising the steps of:

[00104] a) provide a fiber-based substrate having a primary surface and a secondary surface;

[00105] b) forming a dispersion coating layer by applying a dispersion coating composition, as defined with reference to the first aspect, to the first principal surface and drying the applied dispersion coating composition. Petition 870250083635, dated 09 / 17 / 2025, page 33 / 53 28 / 37

[00106] In some modalities, the method also includes:

[00107] c) form a heat-sealable liquid barrier on the second main surface.

[00108] In some embodiments, the composition of the dispersion coating is further defined as set out in this document, with reference to the first aspect.

[00109] In some embodiments, the fiber-based substrate is further defined, as set forth herein with reference to the second aspect.

[00110] The invention method can be implemented online on full-scale paper or cardboard machines.

[00111] The dispersion coating layer is preferably formed by means of a liquid film coating process, whereby the dispersion coating composition is applied to the substrate, spread in a thin, uniform layer, and then dried.

[00112] In some embodiments, the dispersion coating composition is applied at a basis weight in the range of 5-40 g / m2, preferably in the range of 5-30 g / m2 and more preferably in the range of 5-20 g / m2, based on dry weight. The thickness of the wet dispersion coating composition when applied to the substrate is typically in the range of 20-100 μm, preferably in the range of 20-50 μm. Consequently, it is preferable that the dispersion coating composition be free of particles or agglomerates of particles larger than 20-50 μm. Thus, in some embodiments, the dispersion coating composition is free or substantially free of particles. Petition 870250083635, dated 09 / 17 / 2025, page 34 / 53 29 / 37 or particle clusters with a particle size above 50 μm, above 20 μm or above 15 μm.

[00113] In some embodiments, the dispersion coating composition is applied by a non-contact application method. In some embodiments, the dispersion coating composition is applied by an application method selected from the group consisting of roller coating, spray coating, curtain coating, blade coating, slit coating, immersion coating, rotogravure roller coating, direct reverse rotogravure coating, rod coating, soft-tip blade coating, short dwell and soft-tip rod coating and combinations thereof. In some embodiments, the dispersion coating composition is applied by blade coating or rod coating. The dispersion coating composition can be applied directly to the fiber-based substrate or indirectly, for example, by means of a transfer roller or belt.

[00114] In order to minimize the risk of holes in the dispersion coating layer, the dispersion coating layer can be formed by applying the dispersion coating composition in two or more stages with intermediate drying between stages. In such embodiments, the dispersion coating composition in each stage can be applied at a basis weight in the range of 510 g / m2, based on dry weight. In some embodiments, the dispersion coating composition applied in the first stage may be different from the composition of Petition 870250083635, dated 09 / 17 / 2025, page 35 / 53 30 / 37 dispersion coating applied in the second stage. In some embodiments, the PHA particles in the dispersion coating composition applied in the second stage have an average particle size that is smaller than the average particle size of the particles in the dispersion coating composition applied in the first stage. In some embodiments, the median particle size of PHA in the second stage is at least 10% smaller, preferably at least 20% smaller, and more preferably at least 30% smaller, than the median particle size of PHA in the first stage.

[00115] In some embodiments, drying comprises subjecting the dispersion coating composition to heating. In some embodiments, drying comprises subjecting the dispersion coating composition to at least one non-contact drying step, such as infrared radiation, electron beam radiation, ultraviolet radiation, microwave radiation, hot air, impact, or a combination thereof. Optionally, the dispersion coating composition is then subjected to at least one additional drying step, which may be a hot air drying step or a contact drying step, such as heat conduction drying, for example, using a heated belt or heated cylinders.

[00116] In some embodiments, the dry dispersion coating layer has a basis weight in the range of 5-40 g / m2, preferably in the range of 5-30 g / m2 and more preferably in the range of 5-20 g / m2. In some embodiments, the dry dispersion coating layer has a thickness in the range of 8-20 μm. Petition 870250083635, dated 09 / 17 / 2025, pp. 36 / 53 31 / 37

[00117] In some embodiments, the dispersion-coated fiber-based substrate obtained is further defined as set out in this document with reference to the second aspect.

[00118] In some embodiments, both the fiber-based substrate provided in a) and the dispersion-coated fiber-based substrate obtained in b) have an L&W (15°) flexural strength of at least 145 mN (MD), as determined in accordance with ISO 2493-1.

[00119] According to a fourth aspect illustrated in this document, a packaging container is provided comprising a dispersion-coated fiber-based substrate, as defined with reference to the second aspect.

[00120] The dispersion-coated coating layer of the fiber-based substrate of the invention has been found to be particularly useful as a moisture / liquid barrier for use on the outer surface of food and liquid packaging containers. Thus, in some embodiments, the primary dispersion-coated surface forms an outer surface of the container.

[00121] The packaging container is particularly useful for liquids, fatty foods, dry foods and / or frozen foods. In some embodiments, the packaging is a beverage container, preferably a cup.

[00122] In some forms, the packaging container is biodegradable and compostable according to standard EN 13432. Petition 870250083635, dated 09 / 17 / 2025, page 37 / 53 32 / 37

[00123] The fiber-based substrates coated by dispersion of the present disclosure preferentially exhibit some or all of the following properties: - Low coating weight, preferably in the range of 5-20 g / m2 - Dispersion coating layer substantially free of pores - Low COBB600 value, preferably below 25 g / m2 — Grease resistance, KIT value preferably > 10. Good resistance to cracking. - Repulpable, PTS rejection rate as determined according to the PTS RH 021 / 97 test method for Category II products, preferably below 20%. Compostable for home and industrial use — Printable

[00124] Generally, although products, polymers, materials, layers and processes are described in terms of “comprising several components or steps”, products, polymers, materials, layers and processes may also “consist essentially of” or “consist of several components and steps”.

[00125] Although the invention has been described with reference to several exemplary embodiments, it will be understood by those skilled in the art that various alterations may be made, and equivalents may be substituted for elements thereof, without departing from the scope of the invention. Furthermore, many modifications may be made. Petition 870250083635, dated 09 / 17 / 2025, page 38 / 53 33 / 37 to adapt a particular situation or material to the teachings of the invention without departing from its essential scope. Therefore, it is intended that the invention is not limited to the specific embodiment disclosed as the best contemplated mode for carrying out this invention, but that the invention includes all embodiments that fall within the scope of the appended claims. EXAMPLES

[00126] In order to evaluate the dispersion coating composition of the invention, a series of tests were carried out. The dispersion coating compositions were prepared by adding dry PHA to a water-based solution containing the dispersant, after which the other components were added. All percentages are calculated as dry solids content (% by weight). Example 1 (comparative) - PVOH as a dispersant with filler particles

[00127] A dispersion of poly(3-hydroxybutyrateco-3-hydroxyhexanoate) (PHBH) with a PVOH-based dispersant was prepared and filler particles were added (see Table 1, Reference 1). The stability of the dispersion was low, resulting in graininess and uneven coating quality. Cardboard was coated on one side with the dispersion coating composition in a pilot rod coater, and the barrier and stiffness properties of the coated cardboard were evaluated. The cardboard was coated in two stages, with intermediate drying between them. The COBB600 values ​​were high, indicating poor water barrier properties. The dispersion coating composition produced a large amount of Petition 870250083635, dated 09 / 17 / 2025, page 39 / 53 34 / 37 foam during preparation and also later during the disintegration of the sample sheets. Example 2 (comparative) - PVOH as a dispersant without filler particles

[00128] A dispersion of poly(3-hydroxybutyrateco-3-hydroxyhexanoate) (PHBH) was prepared with a PVOH-based dispersant (see Table 1, Reference 2). The stability of the dispersion proved to be weak, resulting in uneven granulation and coating quality. Cardboard was coated with the dispersion coating composition in a pilot rod coater, and the barrier and stiffness properties of the coated cardboard were evaluated. The cardboard was coated on one side in two stages, with intermediate drying between them. The COBB600 values ​​were high, indicating poor water barrier properties. The dispersion coating composition produced a large amount of foam during preparation and also subsequently during the disintegration of the sample sheets. Example 3 - Sorbitol as a dispersant without filler particles

[00129] A dispersion of poly(3-hydroxybutyrateco-3-hydroxyhexanoate) (PHBH) was prepared with sorbitol as dispersant (see Table 1, Dispersion 1). A rheology modifier (water-soluble polysaccharide) was added to the dispersion, and a small amount of antifoaming agent was added to control air bubbles in the dispersion caused by rigorous mixing during preparation. The stability of the dispersion proved to be good, resulting in a uniform coating quality. Petition 870250083635, dated 09 / 17 / 2025, pages 40 / 53 35 / 37 Cardboard was coated with a dispersion coating composition in a pilot rod coater, and the barrier and stiffness properties of the coated cardboard were evaluated. The cardboard was coated on one side in two stages, with intermediate drying between them. The COBB600 values ​​were low, indicating good water barrier properties. Grease resistance measured by the KIT method according to TAPPI standard T 559 proved acceptable. The dispersion coating composition did not produce foam formation during preparation or subsequently during the disintegration of the sample sheets. Example 4 - Sorbitol as a dispersant with charged particles

[00130] A dispersion of poly(3-hydroxybutyrateco-3-hydroxyhexanoate) (PHBH) with sorbitol as dispersant was prepared (see Table 1, Dispersion 2). A rheology modifier and filler particles were added to the dispersion, and a small amount of antifoaming agent was added to control air bubbles in the dispersion caused by rigorous mixing during preparation. The stability of the dispersion was good, resulting in a uniform coating quality. Cardboard was coated with the coating composition by dispersion in a pilot rod coater, and the barrier and stiffness properties of the coated cardboard were evaluated. The cardboard was coated on one side in two stages, with intermediate drying between them. A coating on cardboard was prepared as set out in Table 2. The COBB600 values ​​were low, indicating good water barrier properties. The KIT value was good. The composition of Petition 870250083635, dated 09 / 17 / 2025, pp. 41 / 53 36 / 37 Dispersion coating did not produce foam formation during preparation or subsequently during the disintegration of the sample sheets. Example 5 - Different compositions of dispersion coatings

[00131] Cardboard was coated with a dispersion coating composition in a pilot rod coating machine, and the barrier and stiffness properties of the coated cardboard were evaluated. The cardboard was coated on one side in two stages, with intermediate drying between them. The coating was prepared as set out in Table 2 using Dispersion 1 from Example 3 in the first coating stage and Dispersion 2 from Example 4 in the second coating stage. The COBB600 values ​​were low, indicating good water barrier properties. The KIT was acceptable. The dispersion coating composition did not produce foaming during preparation or subsequently during the disintegration of the sample sheets. Table 1 - Dispersion coating compositions Raw Material Reference 1 Reference 2 Dispersion 1 Dispersion 2 PHBH 56 79 84.6 76.5 Talc 32 9.5 Dispersant 1 11.2 20.2 Dispersant 2 14.8 13.4 Rheology Modifier 0.8 0.8 0.5 0.5 Petition 870250083635, dated 09 / 17 / 2025, pp. 42 / 53 37 / 37 Raw Material Reference 1 Reference 2 Dispersion 1 Dispersion 2 Defoamer 0.05 0.05 NaOH 0.05 0.05 Total dry content 57 48.2 47.2 47 Visual agglomerates Yes, large agglomerates Yes, large agglomerates Stable, homogeneous No agglomeration, Stable and homogeneous dispersion Table 2 - Samples of cardboard coated with dispersion Example 1 Example 2 Example 3 Example 4 Example 5 Number of layers 2 2 2 2 2 Coating weight 15 17 17 20 19 Dispersion type Reference 1 Reference 2 Dispersion 1 Dispersion 2 Dispersion 1 + Dispersion 2 Grammage 248 250 250 253 251 KIT <1 9 7 12 7 Cobb600 >60 48 11 13 21 WVTR (23C / 50%) Above the range 74 NA 17 NA

Claims

1. A dispersion coating composition for coating a fiber-based substrate, said dispersion coating composition, CHARACTERIZED in that it comprises, in liquid medium: 50 to 99% by weight of PHA (polyhydroxyalkanoate) particles, based on the total solids content of the dispersion coating composition, and 1 to 50% by weight of low molecular weight polyol dispersant, based on the total solids content of the dispersion coating composition, wherein the dispersion coating composition has a total solids content in the range of 20-80% by weight.

2. Dispersion coating composition according to claim 1, CHARACTERIZED in that the PHA particles have a unimodal particle size distribution.

3. A dispersion coating composition according to any of the preceding claims, CHARACTERIZED in that the PHA particles have an average particle size (D50) below 15 µm, preferably below 12 µm and, more preferably, in the range of 0.5 to 11 µm or in the range of 0.8 to 8 µm.

4. Dispersion coating composition according to any of the preceding claims, CHARACTERIZED in that the dispersion coating composition is free or substantially free of particles or particle agglomerates with a particle size above 50 µm, above 20 µm or above 15 µm. Petition 870250083635, dated 09 / 17 / 2025, pp. 44 / 53 2 / 4 5. Dispersion coating composition, according to any of the preceding claims, CHARACTERIZED in that the PHA particles comprise PHA in an amount of 70 to 99.9% by weight, preferably in an amount of 90 to 99.9% by weight, based on the dry weight of the PHA particles.

6. Dispersion coating composition according to any of the preceding claims, CHARACTERIZED in that the PHA is selected from the group consisting of poly(3-hydroxyoctanoate) (PHO), poly(3-hydroxydecanoate) (PHD), poly(3-hydroxyhexanoate) (PHH) and poly(3-hydroxyvalerate) (PHV), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH), poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P3HB4HB), poly(3-hydroxyoctanoate-co-3-hydroxyhexanoate) (PHOHH), poly(3-hydroxyoctanoate-co-3-hydroxydecanoate) (PHOHD) and poly(3-hydroxyoctanoate-co-3-hydroxydodecanoate) (PHDHDD) or a combination thereof.

7. Dispersion coating composition according to any of the preceding claims, CHARACTERIZED in that the dispersion coating composition comprises 3 to 35% by weight, and more preferably 5 to 30% by weight of the low molecular weight polyol dispersant, based on the total solids content of the dispersion coating composition.

8. Dispersion coating composition according to any of the preceding claims, CHARACTERIZED in that the low molecular weight polyol dispersant has a molecular weight in the range of 50 to 2000 g / mol, preferably in the range of 50 to 1500 g / mol, and more preferably in the range of 50 to 1000 g / mol or in the range of 50 to 500 g / mol.

9. Dispersion coating composition according to any of the preceding claims, CHARACTERIZED in that the low molecular weight polyol dispersant is selected from the group consisting of low molecular weight polysaccharides and sugar alcohols, and combinations thereof.

10. Fiber-based substrate coated by dispersion, CHARACTERIZED in that it comprises: a fiber-based substrate with a primary surface and a secondary surface, a dispersion coating layer comprising 50 to 99% by weight of PHA (polyhydroxyalkanoate) particles, based on the total solids content of the dispersion coating layer, and 1 to 50% by weight of low molecular weight polyol dispersant, based on the total solids content of the dispersion coating layer, on the primary surface.

11. Fiber-based substrate coated by dispersion according to claim 10, CHARACTERIZED in that the dispersion coating layer comprises 3-35% by weight, and more preferably 5-30% by weight of low molecular weight polyol dispersant, based on the total solids content of the dispersion coating layer.

12. Fiber-based substrate coated by dispersion according to any of claims 10 Petition 870250083635, dated 09 / 17 / 2025, page 46 / 53 4 / 4 to 11, CHARACTERIZED in that the low molecular weight polyol dispersant has a molecular weight in the range of 50 to 2000 g / mol, preferably in the range of 50 to 1500 g / mol and, more preferably, in the range of 50 to 1000 g / mol or in the range of 50 to 500 g / mol.

13. Fiber-based substrate coated by dispersion according to any one of claims 10 to 12, CHARACTERIZED in that the low molecular weight polyol dispersant is selected from the group consisting of low molecular weight polysaccharides and sugar alcohols, and combinations thereof.

14. Method for manufacturing a dispersion-coated fiber-based substrate, CHARACTERIZED in that said method comprises the steps of: a) providing a fiber-based substrate with a primary surface and a secondary surface; b) forming a dispersion coating layer by applying a dispersion coating composition, according to any one of claims 1 to 9, to the primary surface and drying the applied dispersion coating composition.

15. Packaging container, CHARACTERIZED in that it comprises a fiber-based substrate coated by dispersion, according to any one of claims 10 to 13.