Cellulose-based material

Abstract

The present invention relates to a cellulose-based material comprising micronised cellulose fibres, a microfibrillated cellulose material, at least one plasticiser and at least one gelling agent, having properties of strength, hydrophobicity, thermal stability, uniformity, smoothness and biodegradability / compostability, thereby constituting a natural, sustainable and non-artificial alternative to leathers of animal and artificial / synthetic origin. The invention also relates to a process for producing the cellulose-based material.

Description

[0001] DESCRIPTION

[0002] TITLE OF THE INVENTION

[0003] CELLULOSIC BASE MATERIAL

[0004] TECHNICAL DOMAIN

[0005] The present invention relates to a cellulosic-based material and a process for its production.

[0006] PREVIOUS TECHNIQUE

[0007] Animal leather, also known as genuine leather, produced from hides and skins (byproducts of the meat and dairy industries), is manufactured through a series of mechanical and chemical operations that, in short, involve the preparation of the hides, tanning, and finishing. These different operations give rise to environmental problems related to the generation of wastewater and solid waste, and the emission of contaminants into the atmosphere.

[0008] Furthermore, animal leather is mostly finished with a coating of polyvinyl chloride (PVC) or polyurethane (PU) to obtain a uniform, resistant, and shiny fabric, which means that even this naturally based product contains polymers of fossil origin, compromising its biodegradability and recyclability. The relevance of these facts becomes crucial when we realize that the European Union is a major player in the global leather market and maintains its position as the world's leading exporter of semi-processed leather.Therefore, the European Commission is working intensively to promote innovation and environmental protection for a sustainable textile / leather value chain that focuses not only on natural-based materials and production processes, but also on their end-of-life scenarios and the value chain's ability to integrate a functional circular economy, which includes finding substitutes for synthetic leather-like textiles and finishing coatings used in the animal leather industry based on non-biodegradable fossil polymers.

[0009] Among the wide variety of leather applications, the most important markets for producers within the European Union are footwear, leather goods / accessories, clothing, furniture, and the automotive industry. Therefore, the European Union is creating new regulations to push the leather industry towards a more sustainable and circular transition path for a significant market transformation, involving the eco-design of new alternative textile / leather solutions, taking into account their biodegradability, reuse, recycling, and circularity performance.

[0010] Thus, in an attempt to replace animal leather, also driven by veganism and concerns about animal rights (Julia Rufe et al., Consumer response to bio-based products - A systematic review, Sustainable Production and Consumption, Volume 34, 2022, 353-370), synthetic leather, also known as napa, faux leather, artificial or imitation leather, which mimics the appearance and texture of animal leather, is becoming an increasingly popular alternative. One type of synthetic leather developed consists of a polyester mesh base coated with PU and / or PVC. However, once again, the processing and use of these fossil-based products have several negative effects on the environment, with the resulting end product rarely being recycled (Vinay, M. Sustainable textiles through microbe-produced bioleather. Commun Eng 1, 22 (2022)).

[0011] Um outro tipo de couro sintético são os produzidos a partir de fungos (Amobonye, A. et al. Fungal mycelium as leather alternative: A sustainable biogenic material for the fashion industry. Sustainable Materials and Technologies 38 (2023) e00724 ) ou resíduos agricolas, como uvas, fibras de ananás ou folhas de árvores (Yang, M. et al. An environment-friendly leather waste-based liquid film mulching and its application for facilitating the growth of maize crops. Process Safety and Environmental Protection, Vol. 159, 2022, Pages 1236-1244; Duangsuwan, S. et al. Development of Green Leather Alternative from Natural Rubber and Pineapple Leaf Fiber. Sustainability 2023, 15 (21 ), 15400; Nguyen, H. et al. Silane-modified kombucha-derived cellulose / polyurethane / polylactic acid biocomposites for prospective application as leather alternative. Sustainable Materials and Technologies, Volume 36, July 2023, e00611 ).These products perform well compared to animal leather and are competitively priced. However, in most cases, they still require some chemical treatment or the addition of fossil-based finishing substrates / coatings to form a three-dimensional structure similar to leather. Fungus-based solutions still present significant difficulties regarding scaling up their production. We also find alternatives to animal leather based on cellulosic materials, such as bacterial cellulose (BC) (da Silva Junior, CJG et al.; Design of a Naturally Dyed and Waterproof Biotechnological Leather from Reconstituted Cellulose. J. Funct. Biomater. 2022, 13, 49; Konstantin Kriechbaum et al.; Antioxidant and UV-Blocking inspired nanocellulose-based films with high wet strength, Biomacromolecules 2020 21 (5), 1720-1728).Bacterial cellulose is produced by microorganisms, which remains an expensive, time-consuming, and complex process that can hardly meet the demand of the textile industry. Additionally, the hydrophilic nature and liquid absorption capacity of bacterial cellulose present further challenges for the leather industry, which requires water-resistant materials that remain dry in rainy conditions or after spills.

[0012] Therefore, the application of these products has not yet materialized in large-scale production and is still limited to only a few areas or brands. It remains necessary, therefore, to develop other types of synthetic leather that overcome the disadvantages of existing solutions.

[0013] Patent application W02023164005A describes a material for use as a leather substitute consisting of chitosan, micro and nano-fibrillated cellulose, pigments such as ochre or carbon black, plasticizers such as glycerol or sorbitol, crosslinking agents such as glutaraldehyde, glyoxal or sugar aldehyde, and an organic acid such as citric acid. The production process for this product involves steps such as mixing the components until homogeneous, melting in a mold, and evaporating water by heating. Patent KR102081508B1 describes a leather material based on natural fibers with antimicrobial, durability, and breathability properties, resulting from the treatment of a fiber substrate, such as cotton, hemp, and wood, with a solution of algae extracts, composed of starch, agar, carrageenan, alginic acid, and alginate, by spray application or by immersion of the substrate in the extract solution.

[0014] Application CN104480740A describes a type of polyurethane-based synthetic leather consisting of three layers: a base fabric layer, a foam layer, and a surface layer. The surface layer consists of a mixture of different materials, including materials such as water-based polyurethane resin, sodium caseinate, and seaweed powder; the intermediate foam layer consists of materials such as water-based polyurethane resin, calcium carbonate, and carbon black.

[0015] Patent application W02024100420A1 introduces a new type of leather-like material produced from protein extracts derived from grain byproducts of the brewing and distillation industries and their reaction with a crosslinking agent. This crosslinking agent can be a linking reagent such as citric acid, sebacic acid, formaldehyde, glutaraldehyde, benzaldehyde, oxalic acid, among others, or a crosslinking catalyst such as one of the enzymes transglutaminase, lysyl oxidase, and laccase. The synthetic leather of patent application W02024100420A1 may additionally include a polysaccharide isolated from algae or its respective salt. Polysaccharides can include, among others, algin, fucoidan, laminarin, alginic acid, agar-agar, and carrageenan. Patent application WO2022051225A1 describes a sustainable and ecological alternative to traditional leather, consisting of chitosan, silk peptide, lactic acid, and coloring additives.Its production process involves simple steps such as mixing all the components, adding warm water, and mixing at low speed with the final addition of lactic acid. The product, once formed, can be coated with beeswax or shellac to make it more water-resistant.

[0016] Globally, the challenge of using natural-based materials to replace fossil-based polymer products continues to lie in their performance, accessibility, production availability, and price. Often, biodegradable polymers with good mechanical properties are too expensive to be considered a viable alternative to those already on the market. And those that are easily accessible / cheap and can be produced on a large scale do not demonstrate good performance. This is why most of the more sustainable leather options currently available remain a combination of natural-based and non-biodegradable materials, making a significant contribution to a more ecological approach, but still hindering recycling / decomposition and enabling an efficient circular textile economy.

[0017] The development of alternatives to animal leathers is thus a constantly evolving area, and the emergence of alternative solutions is expected and necessary with regard to their composition, the nature of their constituents, and production methods. SUMMARY OF THE INVENTION

[0018] The present invention relates to a cellulosic-based material comprising 10-40% w / w of a microfibrillated cellulosic material, 5-20% w / w of micronized cellulose fibers, 5-30% w / w of at least one gelling agent and a further 20-50% w / w of at least one plasticizer.

[0019] In a preferred embodiment of the invention, the cellulosic base material further comprises 0.25-2% w / w of at least one crosslinking agent.

[0020] In a preferred embodiment of the invention, the cellulosic base material further comprises 0.25-5% w / w of at least one hydrophobic additive.

[0021] In a preferred embodiment of the invention, the cellulosic base material further comprises 0.25-2% w / w of at least one crosslinking agent and 0.25-5% w / w of at least one hydrophobic additive.

[0022] In a preferred embodiment of the invention, the cellulosic base material consists of 6.4% w / w of at least one gelling agent, 25.5% w / w of microfibrillated cellulosic material, 6.4% w / w of micronized cellulose fibers, 25.5% w / w of at least one plasticizer, 1.0% w / w of at least one crosslinking agent, and 1.3% w / w of at least one hydrophobic additive, the remaining percentage being water.

[0023] In a preferred embodiment of the invention, the microfibrillated cellulosic material is selected from the group consisting of Kraft pulp microfibrillated cellulosic material, high-yield Kraft pulp microfibrillated cellulosic material, unbleached Kraft pulp microfibrillated cellulosic material, bleached Kraft pulp microfibrillated cellulosic material, semi-bleached Kraft pulp microfibrillated cellulosic material, sulfite pulp microfibrillated cellulosic material, unbleached sulfite pulp microfibrillated cellulosic material, bleached sulfite pulp microfibrillated cellulosic material, semi-bleached sulfite pulp microfibrillated cellulosic material, and their combinations.

[0024] In a preferred embodiment of the invention, the micronized cellulose fibers are selected from the group consisting of micronized cellulose fibers from Kraft pulp, high-yield micronized cellulose fibers from Kraft pulp, unbleached micronized cellulose fibers from Kraft pulp, bleached micronized cellulose fibers from Kraft pulp, semi-bleached micronized cellulose fibers from Kraft pulp, sulfite micronized cellulose fibers from sulfite pulp, unbleached micronized cellulose fibers from sulfite pulp, bleached micronized cellulose fibers from sulfite pulp, semi-bleached micronized cellulose fibers from sulfite pulp, and combinations thereof.

[0025] In a preferred embodiment of the invention, the Kraft cellulose pulps are eucalyptus Kraft cellulose pulps. In a preferred embodiment of the invention, the gelling agent is selected from the group consisting of alginates, carrageenans, galactans, agarans and combinations thereof.

[0026] In a preferred embodiment of the invention, the plasticizer is selected from the group consisting of polyvinyl alcohol, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, glycerol, sorbitol, polyols and combinations thereof.

[0027] In a preferred embodiment of the invention, the crosslinking agent is selected from the group consisting of zinc chloride, magnesium chloride, calcium chloride, potassium chloride, aluminum trichloride, iron chloride, aluminum sulfate, copper sulfate, nickel sulfate, epichlorohydrin, glutaraldehyde, citric acid, and combinations thereof.

[0028] In a preferred embodiment of the invention, the hydrophobic additive is selected from the group consisting of alkyl ketene, alkenyl succinic anhydride, oils, waxes, resins, rosin, and combinations thereof.

[0029] In a preferred embodiment of the invention, the gelling agent is carrageenan, the plasticizer is glycerol, the crosslinking agent is potassium chloride, and the hydrophobic additive is alkyl ketene dimer.

[0030] Another aspect of the present invention is the process for producing the cellulosic base material. The process comprises the following steps:

[0031] a) constitution of an aqueous formulation comprising 0.5-2% w / w of a microfibrillated cellulosic material, 0.25-1% w / w of micronized cellulose fibers, 0.25-1.5% w / w of at least one gelling agent and 0.75-2.5% w / w of at least one plasticizer;

[0032] b) stirring the resulting formulation from step a) at room temperature until a hydrogel is formed; c) dispensing the hydrogel resulting from step b) into molds;

[0033] d) drying the hydrogel resulting from step c) at a temperature between 30°C-80°C until the formation of the cellulosic base material.

[0034] In a preferred embodiment of the invention, the process further comprises, after step c) and before step d), a spraying step of the hydrogel with a solution of at least one crosslinking agent at a mass ratio of 0.02 to 0.08% w / w relative to the aqueous formulation.

[0035] In a preferred embodiment of the invention, the formulation of step a) further comprises 0.015–0.225% w / w of at least one hydrophobic additive.

[0036] In a preferred embodiment of the invention, the formulation of step a) further comprises 0.015–0.225% w / w of at least one hydrophobic additive, and after step c) and before step d) there is also a spraying step of the hydrogel with a solution of at least one crosslinking agent at a mass ratio of 0.02 to 0.08% w / w relative to the aqueous formulation. BRIEF DESCRIPTION OF THE FIGURES

[0037] Figure 1. Schematic representation of the gradual organization of cellulose in the wood fiber wall. A-Cross-section / longitudinal section of wood fibers; B-Fiber fraction formed by macrofibrils; C-Macrofibrils; D-Microfibrils; E-Elementary fibril; F-Set of elementary crystallites; G-Organization of cellulose molecules: the crystalline unit or unit cell (Krassig, HA, "The Fiber Structure", Cellulose, Structure, Accessibility and Reactivity, Gordon and Breach Science Publishers, Polymer Monographs Vol. 11, Yverdon, Switzerland, 1993, Ch. 2, p. 6-4; Parham, RA, "Ultrastructure and Chemistry", Pulp and Paper Manufactures, Vol. l: Propertires of Fibrous Raw Materials and their Preparation for Pulping, MJ Kocurek and F. Stevens (eds.), Canadian Pulp and Paper Association, Canada, 1983, Chap.

[0038] Figure 2. Transmission optical microscope images of cellulose fibers without mechanical treatment (a) and after refining (b) and (c).

[0039] Figure 3. Scanning electron microscope (SEM) image of micronized cellulose fibers (average fibril length 0.234 mm, total fines content 49%, average fibrillar area 1%, and average fibrillar perimeter 1.9%).

[0040] Figure 4. Cellulosic-based materials A', B' and C'.

[0041] Figure 5. Cellulosic-based materials D', E' and F'.

[0042] Figure 6. Cellulosic-based materials G', H' and I'. Figure 7 Images of the compostability tests performed.

[0043] DETAILED DESCRIPTION OF THE INVENTION

[0044] It has been surprisingly and advantageously found that the cellulosic-based material, according to the present invention, constitutes a natural, compostable and biodegradable, sustainable and non-artificial alternative to leathers of animal and artificial / synthetic origin.This new material, based on micronized cellulose fibers (MCF) and a microfibrillated cellulosic material (MCM) in the presence of at least one plasticizer and at least one gelling agent, contrary to expectations—which would be a fragile, inflexible, rough, hydrophilic material lacking moisture resistance, with low thermal stability and poor mechanical performance—unexpectedly mimics the appearance and texture characteristics of animal / synthetic leather and exhibits properties such as robustness (high density and weight), hydrophobic character, thermal stability, uniformity, smoothness, and biodegradability / compostability. It is a plastic-free material (or free of any petroleum-derived raw material) and can be produced in different thicknesses.

[0045] Additionally, these properties can be adapted according to the desired applications, and dyes and / or other additives can be added to provide other functionalities, as well as coatings of various kinds (of natural origin, such as resins / waxes / oils, or other polymers and their combinations). Furthermore, the cellulosic base material of the present invention can also be applied as a finishing coating for animal / synthetic leather or other fabrics as an alternative to the PU / PVC coatings more commonly used in the fashion, textile, packaging and furniture industries.

[0046] Thus, the cellulosic-based material of the present invention is a sustainable and biodegradable solution, capable of meeting high-performance product standards and demonstrating low environmental impact throughout the entire textile value chain, proving to be an alternative to animal leather and petroleum-based synthetic leather.

[0047] Indeed, for the first time, polysaccharides known for their use in the pharmaceutical and food industries, established in the market, easily accessible and available in abundant quantities, surprisingly constitute the cellulosic base material within the scope of the present invention.

[0048] Additionally, the cellulosic base material of the present invention is mostly based on cellulose, which is a natural, abundant, versatile, biodegradable and renewable polymer with exceptional chemical and mechanical properties. In particular, cellulose fibers can form a wide variety of structures and materials that can be designed according to market needs.

[0049] Therefore, the present invention involves the use of microfibrillated cellulosic material (MCM) and micronized cellulose fibers (FCM), produced from cellulose pulp fibers, as a natural base material to design a new sustainable and high-performance cellulosic-based material that is an alternative to animal leather and petroleum-derived artificial / synthetic leather, and also an alternative to fossil-derived finishing coatings used in animal leather / synthetics and other fabrics / substrates. MCM and FCM have similar performance to other cellulosic materials, such as bacterial cellulose and nanofibrillated cellulose, and exhibit relevant chemical and mechanical properties, which can act alone or in combination with other natural and renewable materials to form robust networks. Furthermore, an MCM and FCM production line can be easily adapted to an industrial cellulose pulp production unit.Additionally, it is thus possible to use, in the present invention, a microfibrillated cellulosic material and micronized cellulose fibers from the same cellulose pulp as raw material for its production.

[0050] Additionally, when in the presence of at least one crosslinking agent or at least one hydrophobic additive, the cellulosic base material of the present invention exhibits a robust structure without compromising its flexibility, elasticity, thermal stability, and biodegradability, with an improved hydrophobic character.

[0051] Additionally, when in the presence of at least one crosslinking agent and at least one hydrophobic additive, the cellulosic base material of the present invention exhibits a robust structure without compromising its flexibility, elasticity, thermal stability, and biodegradability, with a superior hydrophobic character. Another aspect of the present invention is the production process of the cellulosic base material of the present invention, which is also not complex, is water-based (without organic solvents or fossil products), and does not require additional toxic / polluting chemicals.

[0052] The solution of the present invention thus solves the problems of the prior art, namely the existence of a cellulosic-based material, of natural origin, biodegradable and compostable, with properties similar to those of animal and synthetic leathers, from readily available and abundant components, and through a production process that is easily scalable and possibly associated with existing industrial units for the production of pulp and paper.

[0053] Within the scope of the present invention, the term "cellulosic-based material" refers to a material composed substantially of cellulose fibers, wherein these fibers result from the treatment of a cellulose pulp by any chemical, biological or mechanical process for that purpose, or by a combination of these three approaches. In turn, cellulose pulps are obtained by disintegrating the three-dimensional structure of wood and individualizing the cellulose fibers constituting its matrix. Generally, this can be done by two methods, the mechanical method or the chemical method, or by a combination of these two approaches. The cellulosic-based material is a fabric-type film that emulates animal and / or artificial / synthetic leather that can be used as a structural component, individually or in combination with other films / fabrics / substrates and / or coatings in products associated with leather, such as those in the textile, footwear, furniture and transport sectors.

[0054] Within the scope of the present invention, the term "formulation" refers to a mixture of compounds that comprise it, as well as to reaction products and decomposition products formed from the materials of the composition.

[0055] Within the scope of the present invention, the mass ratio of the aqueous formulation refers to the quotient between the mass of a compound in the formulation and the total mass of the formulation:

[0056] Mass ratio, % m / m = (mass of compound in the formulation / total mass of the formulation) x 100

[0057] The mass ratio of the aqueous formulation is made up of water.

[0058] Within the scope of the present invention, the composition of the cellulosic base material refers to the ratio between the mass of a compound in the cellulosic base material and the total mass of the cellulosic base material:

[0059] Composition of the cellulosic base material, % w / w = (mass of the compound in the cellulosic base material / total mass of the cellulosic base material*) x 100

[0060] * in equilibrium with the ambient relative humidity (a measure of the amount of water vapor present in the air relative to the maximum amount the air could contain at the same temperature)

[0061] The total and final mass of the cellulosic base material includes the mass of all compounds present in the initial formulation and a mass of water that is acquired according to the ambient relative humidity.

[0062] Within the scope of the present invention, a gelling agent refers to, for example, sulfated polysaccharides, a complex group of sugars with a variety of relevant biological properties. They are macromolecules comprising sulfate molecules in their carbohydrate structure. These polymers, of an anionic nature, are widespread in nature and occur in organisms such as mammals and invertebrates. In addition to terrestrial organisms and plants, marine algae are considered the most abundant sources of non-animal sulfated polysaccharides. There are alginates, laminarins and fucoidans from brown algae (Phaeophyceae), carrageenans, agarans, galactans and mannans from red algae (Rhodophyceae) and ulvans from green algae (Chlorophyceae).

[0063] Within the scope of the present invention, a plasticizer refers to the class of organic compounds belonging to the alcohol family, in which in the glycol molecule two hydroxyl groups (-OH) are attached to different carbon atoms.

[0064] Within the scope of the present invention, a crosslinking agent refers to an additive that links two polymer chains through a covalent or ionic bond.

[0065] Within the scope of the present invention, a Kraft cooking process refers to Kraft cooking or sulfate cooking. This is a well-known chemical process in the art that consists of cooking wood in a cooking liquor usually composed of sodium hydroxide and sodium sulfide, at temperatures of the order of 140 to 180 °C, in pressurized reactors. A conventional Kraft process is understood here as a typical chemical cooking process that yields a pulp production rate of about 45-55%.

[0066] Within the scope of the present invention, Kraft cellulose pulp refers to a cellulose pulp obtained by conventional Kraft cooking.

[0067] Within the scope of the present invention, high yield corresponds to yields > 60% within a Kraft cooking chemical process.

[0068] Within the scope of the present invention, the cooking yield is calculated using the following formula:

[0069] dough / wood paste x 100

[0070] (weights on a completely dry basis)

[0071] Thus, within the scope of the present invention, a high-yield Kraft cooking process corresponds to a Kraft chemical cooking process where yields > 60% are obtained.

[0072] Within the scope of the present invention, high-yield Kraft pulp refers to a Kraft pulp produced through a Kraft cooking process with a yield greater than > 60%.

[0073] Within the scope of the present invention, an unbleached Kraft pulp corresponds to a Kraft pulp that is not subjected to any bleaching process, that is, any process of removing residual lignin and contaminants from the pulp after its Kraft cooking. Within the scope of the present invention, a bleached Kraft pulp corresponds to a Kraft pulp that is subjected to at least one bleaching process until it reaches an ISO (ISO 2470) whiteness of > 90%. The bleaching step aims to continue the delignification by the action of oxidizing agents, such as oxygen, chlorine dioxide and hydrogen peroxide.

[0074] Within the scope of the present invention, a semi-bleached Kraft pulp corresponds to a pulp that is subjected to at least one bleaching process until it reaches an ISO whiteness (ISO 2470) between that of unbleached pulp and that of bleached pulp.

[0075] Within the scope of the present invention, a sulfite cooking process refers to a well-known process in the art that consists of cooking wood with sulfites or bisulfite salts of sodium, calcium, potassium, magnesium, and ammonium. Solutions of these sulfites or bisulfites are used to treat wood chips, leading to the cleavage of the chemical bonds between cellulose and lignin. During this process, the lignin is converted into soluble lignosulfonates, and this compound is then easily separated from the cellulose fibers.

[0076] Within the scope of the present invention, sulfite-coated cellulose pulp refers to a cellulose pulp obtained by cooking with sulfite.

[0077] Within the scope of the present invention, an unbleached sulfite pulp corresponds to a sulfite pulp that is not subjected to any bleaching process, that is, any process of removing residual deliniin and contaminants from the pulp after its sulfite cooking.

[0078] Within the scope of the present invention, a bleached sulfite pulp corresponds to a sulfite pulp that is subjected to at least one bleaching process until it reaches an ISO (ISO 2470) whiteness of > 90%. The bleaching step aims to continue the delignification by the action of oxidizing agents, such as molecular oxygen, chlorine dioxide and hydrogen peroxide.

[0079] Within the scope of the present invention, a semi-bleached sulfite pulp corresponds to a sulfite pulp that is subjected to at least one bleaching process until it reaches an ISO whiteness (ISO 2470) between that of unbleached pulp and that of bleached pulp.

[0080] Wood and plant fibers are morphological cellular elements. As plant cells, wood and plant fibers possess a cell wall. The cell wall presents a structural hierarchy that begins with the cellulose chain, hence the specific designation is cellulosic fiber, due to its composition being mainly constituted by cellulose, a linear polysaccharide composed of PD-glucopyranose units, and may also include other polysaccharides and lignin in its composition. The cellulose chains group together and form the elementary cellulosic fibril. In turn, the elementary fibrils group together, and the resulting unit from each group of elementary fibrils is designated as a cellulosic microfibril. The orientation of the microfibril in the cell wall relative to the cell axis is one of the factors that allows the differentiation of the cell wall into distinct layers (Figure 1).Microfibrils are obtained by fibrillating cellulosic fibers, in which the microfibril is physically detached from the cellulosic fiber. This occurs when cellulosic fibers from wood and plants, obtained from a cellulose pulp of cellulosic fibers (the pulp being obtained by disaggregating the three-dimensional structure of the wood and individualizing the cellulose fibers that constitute its matrix – this disaggregation can be carried out by three methods: mechanical, chemical, biological, or enzymatic, or by any combination of these methods), are mechanically treated, preceded or not by at least one other auxiliary treatment (chemical, enzymatic treatments, or any combination of these treatments).This fibrillation can be complete, that is, with physical separation of a microfibril or set of microfibrils from the cell wall along its entire longitudinal dimension, or the fibrillation can be partial, resembling a branching, which may involve a microfibril or a set of microfibrils from each cellulosic fiber. The two fibrillation processes can coexist and may not encompass the entirety of the fibers. Also resulting from fibrillation is material resulting from microfibrils cut longitudinally at points of greater fragility, resulting in fractions of shorter length than the fiber or fibril that originated them.

[0081] Thus, within the scope of the present invention, a microfibrillated cellulosic material refers to cellulosic material resulting from the treatment of cellulose pulps for their fibrillation. In fact, the term microfibrillated is associated with the effect on the fiber that promotes the separation (partial or total) of microfibrils from the cell wall from which it originated. The term "cellulosic material" is associated with its origin, of a fibrous and cellulosic base, but it must be distinguished from cellulosic fiber, a plant cell, due to the alterations resulting from its processing, as there is a compromise of the structural hierarchy that underlies the concept of a plant cell.

[0082] Processes for fibrillating cellulosic fibers consist of processes that result in the application of compression and shear forces in an aqueous medium, also causing the cellulosic fibers to swell. The specialist in the technique has various techniques and means to promote the mechanical treatment of cellulosic fibers in order to promote their fibrillation. Examples of this type of mechanical process are refining, grinding, maceration, and shearing. Additionally, cellulosic fibers can be pre-treated enzymatically or chemically, for example, to reduce the amount of hemicellulose or lignin and / or to create zones more susceptible to the action of subsequent mechanical treatments, thus making them more targeted and effective.

[0083] The Shopper-Riegler (SR) degree, which reflects the drainage rate of a given volume of water through a suspension of a cellulose fiber pulp, is one of the first parameters to be measured in microfibrillated cellulosic material and compared with the cellulose pulp from which it originated through processing that promotes fibrillation. It corresponds to an empirical measure of cellulose pulp refining, in which a quantity of 1000 mL corresponds to 0 oSR, while a zero amount of drained liquid corresponds to 100°SR (ISO 5267 / 1). Other parameters relevant to identifying the effect of fibrillation on cellulosic fibers are the morphological parameters of the resulting microfibrillated cellulosic material, here designated as fibrillation parameters, such as the average fibril length, the average fibrillar area %, the average fibrillar perimeter %, and the total fines content %, parameters in accordance with ISO 16065-2 (Pulps - Determination of fiber length by automated optical analysis. Part 2: Unpolarized light method). The equipment used for these measurements, and within the scope of the present invention, was the L&W FiberTester Plus+, in which the characterization of the microfibrillated cellulosic material is performed without requiring prior sample treatment, allowing analysis in aqueous medium, a medium in which the material is applied within the scope of this invention.

[0084] The percentage of fines also refers to the percentage of fibers with a length less than or equal to 0.2 mm, measured using an L&W Fiber Tester Plus+, relative to the average length of the entire sample.

[0085] Indeed, the effect of fibrillation on the production of microfibrillated cellulosic material is observed in the final product when compared to cellulosic fibers that are not subjected to fibrillation for the production of a microfibrillated cellulosic material, as observed in the images in Figure 2 (using a transmission optical microscope (Leica brand, Dialux 20EB model)).Figure 2 represents in a) a cellulosic fiber obtained after Kraft cooking of eucalyptus followed by a bleaching process, without refining (Shopper-Riegler degree of 20 °SR, average fibril length 0.807 mm, total fines content 17%, average fibrillar area 0.8% and average fibrillar perimeter 1.6%), in b) a microfibrillated cellulosic material obtained from a mechanical treatment of bleached Kraft eucalyptus pulp (Shopper-Riegler degree of 74 °SR, average fibril length 0.707 mm, total fines content 23%, average fibrillar area 3% and average fibrillar perimeter 8%) and in c) a microfibrillated cellulosic material obtained from a mechanical treatment of unbleached Kraft eucalyptus pulp (Degree Shopper-Riegler above 70°SR, average fibril length 0.693 mm, total fines content 48%, average fibrillar area 20%, and average fibrillar perimeter 36%).That is, Figure 2, in a), b) and c), and in that order, represents an increasing degree of severity with respect to the fibrillation of a cellulose pulp for the production of a microfibrillated cellulose material. The effect of fibrillation is clearly visible in the final product, reflected both in the fibrillation parameters, which undergo a significant increase with the severity of the fibrillation applied, and visually by observing, in b) and c): 1) microfibril or set of microfibrils completely detached, or disaggregated, from the cell wall along its entire longitudinal dimension; 2) branched fiber resulting from the partial detachment of a microfibril or a set of microfibrils; 3) material resulting from microfibrils cut longitudinally at points of greater fragility, resulting in fractions of shorter length than the fiber from which they originated.

[0086] The microfibrillated cellulosic material of the present invention can further be defined by a Schopper-Riegler degree (°SR) greater than 70, an average fibril length of 0.357-0.700 mm, an average fibril width of 20-35 µm, an average fibrillar area of ​​3-32%, an average fibrillar perimeter of 8-60%, and a total fines content of 23-100% (L&W FiberTester Plus +, per ISO 16065-2 (Pulps - Determination of fiber length by automated optical analysis. Part 2: Unpolarized light method)).

[0087] The resulting microfibrillated cellulosic material also exhibits greater flexibility and a larger surface area compared to cellulosic pulp that is not subjected to any fibrillation process for the production of a microfibrillated cellulosic material.

[0088] The microfibrillated cellulosic material of the present invention may additionally be composed of nanofibrils (or nanofibers), or other cellulosic nanomaterials, as defined in ISO / TS 20477 2023-05 Nanotechnologies - Vocabulary for cellulose nanomaterial, resulting from the fibrillation process of a cellulose pulp.

[0089] The microfibrillated cellulosic material of the present invention thus exhibits technical characteristics conferred upon it by the fibrillation process, which are distinctive and unequivocally identifiable in the final product.

[0090] Within the scope of the present invention, micronized cellulose fibers refer to cellulose fibers that are subjected to micronization, that is, a cut mostly transverse to the axis of the plant cell in a dry medium, in which the fibers undergo a reduction in their length to the micrometer range, through mechanical operations, with the objective of reducing the length of the fibers without compromising the structure of the cell wall, as observed in the image of Figure 3 (Scanning Electron Microscope (SEM) TM4000 15kV), unlike the production processes of a microfibrillated cellulosic material (Figure 2, b) and c)). Using analyses by L&W FiberTester Plus+ (and ISO 16065-2 standard) it is possible to confirm the unaltered state of the cell wall, reflected in the low value presented by the parameters related to fibrillation, average fibrillar area and average fibrillar perimeter.In the case of micronized cellulose fibers, these parameters are in the order of 1% average fibrillar area and 1.9% average fibrillar perimeter, similar to the values ​​presented by a fiber without mechanical treatment, and much lower than the values ​​obtained in the case of microfibrillated cellulosic material (average fibrillar area 3-32% and average fibrillar perimeter 8-60%), clearly identifying the difference between these two types of cellulosic materials. The SEM (Scanning Electron Microscope) images, Figure 3, allow us to visually and unequivocally affirm the unaltered state of the cell wall of the micronized cellulose fibers, as well as their length.

[0091] The micronization of cellulose fibers can be carried out by processes such as cutting and grinding, by the action of knives, by the action of balls, or by shearing methods (exclusively mechanical processes), followed by passing through a sieve (depending on the equipment, it can be 200 µm, for example), thus obtaining a cellulosic material with different length dimensions. In this sense, micronized cellulose fibers can present a length distribution of approximately 7% from 0.5 to 1.3 mm, approximately 44% from 0.2 to 0.5 mm, approximately 25% from 0.1 to 0.2 mm, and approximately 25% from 0.001 to 0.1 mm, obtained from the analysis of samples using the L&W FiberTester Plus+ equipment, following the TI standard.

[0092] ISO 16065-2 (Pulps - Determination of fiber length by automated optical analysis. Part 2: Unpolarized light method).

[0093] The micronized cellulose fibers of the present invention thus exhibit technical characteristics conferred by the micronization process, which are distinctive and unequivocally identifiable in the final product.

[0094] Thus, a person skilled in the art identifies and differentiates, within the scope of the present invention, a microfibrillated cellulosic material and micronized cellulose fibers.

[0095] It is also common in the field of this technique to designate microfibrillated cellulosic material and micronized cellulose fibers according to the raw material from which they originate, that is, the type of cellulose pulp from which the material is obtained. Since they are chemically composed of the same elements as the cellulose pulp from which they originate, the intrinsic characteristics of a microfibrillated cellulosic material and micronized cellulose fibers depend directly on the process and raw material used for their production. Thus, it is impossible to characterize them through their chemical constituents, due to their similar nature. The expert in the field identifies the type of cellulosic material in question, and its intrinsic characteristics, by its designation based on the raw material from which it originates and the production method of the raw material and the cellulosic material.

[0096] Microfibrillated cellulosic material and micronized cellulose fibers can be produced using Kraft pulp or sulfite pulp from softwoods and hardwoods.

[0097] Within the scope of the present invention, softwood fibers relate to cellulosic fibers of woods made from, but not limited to, pine, fir and combinations thereof.

[0098] Within the scope of the present invention, hardwood fibers relate to cellulosic fibers from woods of, but not limited to, eucalyptus, birch, acacia, poplar and combinations thereof.

[0099] Within the scope of the present invention, a microfibrillated cellulosic material or micronized cellulose fibers from Kraft pulp relate to a microfibrillated cellulosic material or micronized cellulose fibers produced from Kraft pulp.

[0100] Within the scope of the present invention, a microfibrillated cellulosic material or micronized cellulose fibers from unbleached Kraft pulp relate to a microfibrillated cellulosic material or micronized cellulose fibers produced from unbleached Kraft pulp.

[0101] Within the scope of the present invention, a microfibrillated cellulosic material or micronized cellulose fibers from bleached Kraft pulp relates to a microfibrillated cellulosic material or micronized cellulose fibers produced from bleached Kraft pulp. Within the scope of the present invention, a microfibrillated cellulosic material or micronized cellulose fibers from semi-bleached Kraft pulp relates to a microfibrillated cellulosic material or micronized cellulose fibers produced from semi-bleached Kraft pulp.

[0102] Within the scope of the present invention, microfibrillated cellulosic material or micronized cellulose fibers from high-yield Kraft pulp relate to microfibrillated cellulosic material or micronized cellulose fibers produced from a high-yield Kraft pulp.

[0103] Within the scope of the present invention, a microfibrillated cellulosic material or micronized cellulose fibers from sulfite cellulose pulp relates to a microfibrillated cellulosic material or micronized cellulose fibers produced from a sulfite cellulose pulp.

[0104] Within the scope of the present invention, a microfibrillated cellulosic material or micronized cellulose fibers from unbleached sulfite pulp relates to a microfibrillated cellulosic material or micronized cellulose fibers produced from unbleached sulfite pulp.

[0105] Within the scope of the present invention, a microfibrillated cellulosic material or micronized cellulose fibers from bleached sulfite pulp relates to a microfibrillated cellulosic material or micronized cellulose fibers produced from bleached sulfite pulp. Within the scope of the present invention, a microfibrillated cellulosic material or micronized cellulose fibers from semi-bleached sulfite pulp relates to a microfibrillated cellulosic material or micronized cellulose fibers produced from semi-bleached sulfite pulp.

[0106] Within the scope of the present invention, a hydrophobic additive refers to additives added to the formulation to increase hydrophobic properties.

[0107] Within the scope of the present invention, hydrogel refers to gel-based structures consisting of three-dimensional networks of hydrophilic polymers with high water retention capacity. They can be classified based on composition (natural vs. synthetic), physical structure (amorphous, semi-crystalline, crystalline) and type of crosslinking (ionic vs. covalent). Depending on the ratio of their formulation and degree of crosslinking, hydrogels with different properties are obtained, such as their viscosity, a crucial parameter for their performance and applicability. Additionally, hydrogels can be maintained and used in their initial form, dried at room temperature or higher to form films / layers / barriers, or dried using different techniques, such as freeze-drying or supercritical drying, to remove all water without damaging / collapsing their structure and forming low-density materials, such as foams / sponges.Thus, in all cases, their flexibility / softness, density, and porosity are defined by their original hydrogel formulation. Some hydrogels may be flexible, soft, and brittle, while others may be more robust and / or brittle; this opens the opportunity to design these materials to order for specific applications.

[0108] Within the scope of the present invention, a natural-based material is understood to be a material whose main constituents are substances originally derived from living organisms (e.g., plants, microorganisms), or from components thereof (e.g., enzymes), or biochemicals (i.e., chemical substances that are naturally found in living organisms, such as sucrose, glucose, starch, or natural polyesters).

[0109] Within the scope of the present invention, biodegradable material refers to a material that degrades under biological (primarily microbial) action. Some biodegradable materials are compostable (but not all), meaning they degrade under aerobic conditions, typically within a period of 6 to 12 weeks. Composting of industrial products typically occurs in industrial composting facilities where controlled conditions are provided (e.g., temperature, humidity, aeration). Microorganisms, such as bacteria or fungi and their enzymes, are able to "digest" the chain structure of compostable polymers as a source of nutrition. The resulting end products are water, carbon dioxide (CO2), and residual biomass.

[0110] Within the scope of the present invention, biodegradable materials preferably meet specific compostability requirements according to at least one accepted standardization system, such as ASTM 6400, ASTM 6868, ISO 17088, ISO 18606, EN 13432, EN 14995, or at least one accepted certification system, such as certificates for compostable plastics issued by DIN Certco, Vincotte, Biodegradable Products Institute (BPI, USA), Japan BioPlastics Association (JBPA, Japan), as well as other less commonly used organizations. More particularly, these standardization and certification systems correspond to the latest version in effect on the priority date of this patent application.

[0111] Within the scope of the present invention, basis weight (according to ISO 536) refers to the mass of a material / film / fabric per square meter, and is calculated as follows:

[0112] Grammage (g / m²) 2 ) = sample mass (g) / sample area (m²) 2 )

[0113] Within the scope of the present invention, density (according to ISO 534) refers to the mass of a material compared to its volume, and is calculated as follows:

[0114] Density (g / cm³) 3 ) = sample mass (g) / sample volume (cm³) 3 )

[0115] Within the scope of the present invention, contact angle (0 C The angle between a liquid surface and a solid surface where and when they meet refers to the angle between a liquid surface and a solid surface. Contact angle measurements on the cellulosic-based material samples were performed with ultrapure water (4 pL drops) in a dataphysics OCA 15EC with dpiMAX software, from which the values ​​of 0 C over time (up to 150 seconds) were recorded directly.

[0116] Within the scope of the present invention, tensile strength refers to the maximum tensile stress a material can withstand before it undergoes permanent deformation or rupture, and is calculated using the formula (ISO 3376):

[0117] Tensile strength (MPa) = maximum recorded force (N) / [specimen width * specimen thickness] (mm) 2 In the context of the present invention, tensile strain refers to the percentage of elongation of a material until its permanent deformation or rupture, and is calculated using the formula (ISO 3376):

[0118] Tensile deformation (%) = [ (distance between grips at the point of maximum force (mm) - initial distance between grips (mm) ) / initial distance between grips (mm) ] * 100

[0119] Within the scope of the present invention, the hydrophobic character of a material refers to its tendency to repel water molecules, which is evaluated by measuring the contact angle between a drop of water and the surface of the cellulosic-based material.

[0120] Within the scope of the present invention, scanning electron microscopy (SEM) images, herein referred to as SEM images, refer to images obtained by scanning electron microscopy, a technique that produces images of a sample by scanning its surface with an electron beam. In turn, the electrons interact with the atoms of the sample, producing various signals that contain information about the surface topography. SEM images of cellulosic-based material samples were captured at 15kV on a Hitachi TM4000Plus (Japan).

[0121] Within the scope of the present invention, thermogravimetric analysis (TGA) is a method of thermal analysis in which changes in the physical and chemical properties of materials are measured as a function of increasing temperature (with a constant heating ramp) or as a function of time (with constant temperature and / or constant mass loss). The TGA curves of the cellulosic-based material samples were recorded on a Hitachi STA200RV (Japan) with a constant heating ramp of 10°C / min up to 800°C.

[0122] Within the scope of the present invention, elemental analysis refers to an analytical technique applied in chemistry to determine the elemental composition of chemical compounds and their composites. In the case of the cellulosic-based material samples, the percentages of carbon (C), nitrogen (N), and oxygen (O) were evaluated using a ThermoFisher Scientific Flash 2000 (United States of America).

[0123] Within the scope of the present invention, biodegradability tests relate to compostability tests in accordance with ISO 23517: 2021, carried out on commercial soil (without additives, fertilizers or compost) from the cultivation of catnip (Nepeta cataria) in contact with cellulosic base materials (2x4cm) for 6 weeks, after which its disintegration and biodegradation (%) in relation to its initial mass was evaluated.

[0124] In the context of the present invention, opacity refers to the ratio between the diffuse light reflectance of a material when it is positioned on a standardized high-reflectance background (typically a black plate with 0% reflectance) and the diffuse light reflectance of the same material on a perfectly opaque background (generally a stack of sheets of the same material). Measured according to ISO 2471.

[0125] Within the scope of the present invention, ambient temperature refers to a temperature between about 15 °C and about 30 °C, or more particularly between about 20 °C and about 25 °C. Within the scope of the present invention, forced convection is the heat transfer promoted by the induced movement of a fluid, such as air or liquid, through external forces. This process increases heat exchange by directing and controlling the flow of the fluid over surfaces. Forced convection drying is a moisture removal process in which the movement of a fluid, usually air, is induced by external forces to accelerate the evaporation of water or other liquids from a surface or material, promoting faster and more uniform drying. The person skilled in the art has various techniques and means to promote forced convection drying.

[0126] The cellulosic-based material of the present invention, based on at least one gelling agent, a microfibrillated cellulosic material and micronized cellulose fibers, and at least one plasticizer, without fossil-based products, allows for the achievement of different properties, depending on the intended application, the concentration and mass ratio of the formulation that constitutes it, and may be a robust material with hydrophobic character, thermal stability, uniformity and smoothness, and biodegradability / compostability, which can be used in numerous textile applications, for example, clothing, footwear, accessories, furniture, automotive industry, printed electronics, etc.

[0127] The inclusion of at least one gelling agent allows the product of the present invention to incorporate the formation of a natural-based hydrogel using natural-based compounds. In turn, at least one plasticizer incorporates characteristics of elasticity, flexibility, and smoothness to the product of the present invention. At least one crosslinking agent promotes cross-linking between the different chains / groups of the hydrogel formed by the microfibrillated cellulosic material and micronized cellulose fibers and by the gelling and plasticizing agents to build a network strong enough to form a robust structure without compromising its flexibility, elasticity, biodegradability, and thermal stability.

[0128] The cellulosic base material of the present invention comprising at least one gelling agent, a microfibrillated cellulosic material, micronized cellulose fibers and at least one plasticizer comprises 5 to 30% w / w of at least one gelling agent, preferably 10 to 30% w / w, more preferably 5 to 25% w / w, more preferably 10 to 25% w / w and even more preferably 15 to 20% w / w. The cellulosic base material comprises 10 to 40% w / w of a microfibrillated cellulosic material, preferably 15 to 40% w / w, more preferably 10 to 35% w / w, more preferably 15 to 35% w / w and even more preferably 20 to 30% w / w. The cellulosic base material comprises 5 to 20% w / w of micronized cellulose fibers, preferably 10 to 20% w / w, more preferably 5 to 15% w / w, more preferably 10 to 15% w / w and even more preferably 15 to 20% w / w.The cellulosic base material comprises 20 to 50% w / w of at least one plasticizer, preferably 25 to 50% w / w, more preferably 20 to 45% w / w, more preferably 25 to 45% w / w and even more preferably 30 to 40% w / w. In one embodiment of the invention, the cellulosic base material further comprises at least one crosslinking agent or at least one hydrophobic additive, comprising 0.25 to 2% w / w of at least one crosslinking agent, preferably 0.5 to 2% w / w, more preferably 0.25 to 1.5% w / w, more preferably 0.5 to 1.5% w / w and even more preferably 0.75 to 1.25% w / w. Or the cellulosic base material comprises 0.25 to 5% w / w of at least one hydrophobic additive, preferably 1 to 5% w / w, more preferably 0.25 to 4% w / w, more preferably 1 to 4% w / w and even more preferably 1.5 to 3% w / w.

[0129] In another embodiment of the invention, the cellulosic base material further comprises at least one crosslinking agent and at least one hydrophobic additive, comprising 0.25 to 2% w / w of at least one crosslinking agent, preferably 0.5 to 2% w / w, more preferably 0.25 to 1.5% w / w, more preferably 0.5 to 1.5% w / w and even more preferably 0.75 to 1.25% w / w. The cellulosic base material comprises 0.25 to 5% w / w of at least one hydrophobic additive, preferably 1 to 5% w / w, more preferably 0.25 to 4% w / w, more preferably 1 to 4% w / w and even more preferably 1.5 to 3% w / w.

[0130] Another aspect of the present invention relates to a process for producing the cellulosic base material of the present invention. The process occurs from an aqueous formulation consisting of at least one gelling agent, a microfibrillated cellulosic material, micronized cellulose fibers and at least one plasticizer. The formulation comprises a mass ratio of the gelling agent of 0.25 to 1.5% w / w, preferably 0.5 to 1.5% w / w, more preferably 0.25 to 1% w / w, and even more preferably 1 to 1.5% w / w. The formulation comprises a mass ratio of a microfibrillated cellulosic material of 0.5 to 2% w / w, preferably 1 to 2% w / w, more preferably 0.5 to 1% w / w, and even more preferably 0.75 to 1.25% w / w. The formulation comprises a mass ratio of micronized cellulose fibers of 0.25 to 1% w / w, preferably 0.5 to 1% w / w, more preferably 0.25 to 0.75% w / w, and even more preferably 0.25 to 0.5% w / w.The formulation comprises a mass ratio of a plasticizer of 0.75 to 2.5% w / w, preferably 1 to 2.5% w / w, more preferably 0.75 to 1.5% w / w, and even more preferably 1 to 2% w / w.

[0131] In one embodiment of the invention, the formulation further comprises at least one crosslinking agent or at least one hydrophobic additive. The formulation comprises a mass ratio of at least one crosslinking agent of 0.02 to 0.08% w / w, preferably 0.04 to 0.08% w / w, more preferably 0.02 to 0.06% w / w, and even more preferably 0.04 to 0.06% w / w. Or the formulation comprises a mass ratio of at least one hydrophobic additive of 0.015 to 0.225% w / w, preferably 0.05 to 0.225% w / w, more preferably 0.015 to 0.1% w / w, and even more preferably 0.05 to 0.175% w / w.

[0132] In another embodiment of the invention, the formulation further comprises at least one crosslinking agent and at least one hydrophobic additive. The formulation comprises a mass ratio of at least one crosslinking agent of 0.02 to 0.08% w / w, preferably 0.04 to 0.08% w / w, more preferably 0.02 to 0.06% w / w, and even more preferably 0.04 to 0.06% w / w. The formulation comprises a mass ratio of at least one hydrophobic additive of 0.015 to 0.225% w / w, preferably 0.05 to 0.225% w / w, more preferably 0.015 to 0.1% w / w, and even more preferably 0.05 to 0.175% w / w.

[0133] The process comprises the steps of stirring the formulation at room temperature until a hydrogel is formed, followed by dispensing the resulting hydrogel into molds, and then drying the resulting hydrogel at a temperature between 30°C-80°C until the formation of the cellulosic base material.

[0134] In one embodiment of the invention, the process further comprises a step of spraying the hydrogel with a solution of at least one crosslinking agent before it dries.

[0135] In one embodiment of the invention, drying is carried out by forced convection.

[0136] It is observed that these mass ratios used in the aforementioned aqueous formulation, when subjected to the production process of the present invention, result in the compositions previously disclosed for the cellulosic base material of the present invention. This is to be expected, since, after the drying stage of the process, the resulting proportions of the material obtained are those that were disclosed in this description.

[0137] It should be noted that when specifying any weight range or mass ratio, any particular upper value can be associated with any particular lower value, as well as with any included subranges. In this regard, it should be noted that all ranges disclosed here include endpoints, and endpoints are independently combinable.

[0138] In one embodiment of the present invention, the gelling agent is selected from the group consisting of alginates, carrageenans, galactans, agarans, uvans, and combinations thereof. The different stereoisomers, degrees of sulfation, and molecular weights of these compounds are considered.

[0139] In one embodiment of the present invention, the plasticizer is selected from the group consisting of polyvinyl alcohol (PVOH), ethylene glycol (EG), diethylene glycol (DEG), triethylene glycol (TEG), polyethylene glycol (PEG), propylene glycol (PG), glycerol, sorbitol, polyols and combinations thereof.

[0140] In one embodiment of the present invention, the crosslinking agent is selected from the group consisting of zinc chloride, magnesium chloride, calcium chloride, potassium chloride, aluminum trichloride, iron chloride, aluminum sulfate, copper sulfate, nickel sulfate, epichlorohydrin, glutaraldehyde, citric acid, and combinations thereof.

[0141] In one embodiment of the invention, the hydrophobic additive is selected from the group consisting of an alkyl ketene dimer (AKD), an alkenyl succinic anhydride (ASA), oils, waxes, resins, rosin, and combinations thereof.

[0142] In one embodiment of the present invention, the microfibrillated cellulosic material is selected from the group consisting of microfibrillated cellulosic material from Kraft pulp, high-yield microfibrillated cellulosic material from Kraft pulp, unbleached microfibrillated cellulosic material from Kraft pulp, bleached microfibrillated cellulosic material from Kraft pulp, semi-bleached microfibrillated cellulosic material from Kraft pulp, sulfite microfibrillated cellulosic material, unbleached microfibrillated cellulosic material from sulfite pulp, bleached microfibrillated cellulosic material from sulfite pulp, and microfibrillated cellulosic material from sulfite pulp. semi-bleached and its combinations.Additionally, this microfibrillated cellulosic material can be produced by any mechanical and / or biological and chemical wood treatments, such as enzymatic treatments, individually or in any preferred sequence.

[0143] In one embodiment of the present invention, micronized cellulose fibers are selected from the group consisting of micronized cellulose fibers from Kraft pulp, high-yield micronized cellulose fibers from Kraft pulp, unbleached micronized cellulose fibers from Kraft pulp, bleached micronized cellulose fibers from Kraft pulp, semi-bleached micronized cellulose fibers from Kraft pulp, sulfite micronized cellulose fibers from sulfite pulp, unbleached micronized cellulose fibers from sulfite pulp, bleached micronized cellulose fibers from sulfite pulp, semi-bleached micronized cellulose fibers from sulfite pulp, and combinations thereof.In one embodiment of the present invention, both the microfibrillated cellulosic material and the micronized cellulose fibers are produced from the same type of cellulose pulp, chosen from the Kraft and sulfite cellulose pulps mentioned above. This embodiment is advantageous because it allows the use of the same raw material for both components of the cellulose base material of the invention, resulting in lower production costs and facilitating the adaptation of the production method of the cellulose base material to an industrial cellulose pulp production unit. In a preferred embodiment, this cellulose pulp is a high-yield Kraft cellulose pulp. This type of high-yield cellulose pulp is associated with lower production costs.Additionally, it allows for the natural incorporation of a characteristic brownish hue into the cellulose base material of the present invention, as well as greater mechanical and moisture resistance due to the higher lignin content of this type of pulp compared to other cellulose pulps resulting from a typical Kraft process.

[0144] In one embodiment of the present invention, the microfibrillated cellulosic material and / or micronized cellulose fibers are eucalyptus Kraft pulp.

[0145] The cellulosic-based material of the present invention has uses in different areas, such as fashion, textiles, automotive, electronic and sensor devices, packaging, and furniture. It can be used in the form of alternative fabrics that replace animal and artificial / synthetic leather, and in composites that combine leather (animal and / or artificial / synthetic) with natural-based fabrics (such as cotton) or synthetic fabrics (such as polyester and nylon). In this case, the cellulosic-based material can be used as an intermediate component or as a coating, film, or barrier, replacing the fossil-based materials normally used in these applications.

[0146] It has been found that the combination of microfibrillated cellulosic material, micronized cellulose fibers, at least one gelling agent and at least one plasticizer in the proportions defined in the present invention is crucial for the formation of a stable three-dimensional network capable of producing the cellulosic-based material with the desired properties.

[0147] Compositions outside the ranges defined here, or that do not include at least one of the aforementioned components, tend to result in less cohesive structures or structures with inferior mechanical performance, structural stability, and hydrophobic behavior.

[0148] Examples

[0149] Although the invention is described with reference to several exemplary embodiments, those skilled in the art will understand that various alterations may be made and equivalent elements may be substituted without affecting the scope of the present invention. Furthermore, modifications may be made to adapt a specific situation or material to the teachings of the invention without departing from its scope as defined by the appended claims. Consequently, the invention is not limited to the specific embodiments disclosed for carrying out the present invention, but includes all embodiments disclosed in this description and others covered by the scope of its claims.

[0150] Microfibrillated cellulosic material from a high-yield eucalyptus Kraft pulp was produced as described in patent application WO2023180947A1.

[0151] The additional and optional step of enzymatic hydrolysis was not used. The process thus involved only mechanical steps, without the intervention of chemical agents or enzymes.

[0152] Micronized cellulose fibers from high-yield eucalyptus Kraft pulp were produced through a process involving the following steps:

[0153] a) High-yield Kraft pulp sheets were fed manually and directly from pulp bales, through a feeding chute that guided them to the intake opening of the micronization machine;

[0154] b) upon entering the machine drum, with an opening of 900 nm, the grinding / crushing of the pulp fibers occurred, and size reduction took place between the 64 blades of a fast-rotating rotor (the rotor with a diameter of 500 nm and a width of 1000 nm and the blades with a width of 250 nm) and the 40 stationary blades in 10 rows of blades housed in the drum and with a blade width of 250 nm. The material was subsequently admitted into a removable sieve, installed at the bottom of the equipment, and aspirated through the base of the micronization machine with the aid of a mechanism that generated a suction effect. The resulting micronized cellulose fibers presented a length distribution of approximately 6% from 0.5 to 1.3 mm, approximately 43% from 0.2 to 0.5 mm, approximately 25% from 0.1 to 0.2 mm, and approximately 26% from 0.001 to 0.1 mm.

[0155] Materials

[0156] Microfibrillated cellulosic material from a high-yield eucalyptus Kraft pulp was produced as described in patent application WO2023180947A1, and used in suspension (example: MCM at 2% solids, where for every 100g of suspension, 2g were MCM and 98g were water).

[0157] Micronized cellulose fibers from a high-yield eucalyptus Kraft pulp were produced as described above, and used in powder form with ~10% relative humidity (for every 100g of material, 90g yielded MC and 10g were water).

[0158] Carrageenan (Ceamsa, Spain) and glycerol (Merck, United States of America) were used directly in the formulation. A 13% AKD suspension (for every 100g of suspension, 13g were AKD and 87g were water) was also added directly to the formulation at a ratio of 5% AKD relative to the total mass of dry fiber present in the final formulation (example: for 3g of dry fiber, 0.15g of AKD was added).

[0159] Finally, in the examples presented here, potassium chloride (KCl) in a 2% w / v aqueous solution was used as a crosslinking agent by spraying, in order to obtain a mass ratio of 0.04% w / w in relation to the total mass of the formulation. To standardize the analysis of the results with regard to their characterization in terms of properties, for all examples dried at 35°C with ventilation, 500g of formulation were prepared in flat rectangular molds of 24x24x4cm.

[0160] Example 1 - without the use of a crosslinking agent and without the use of a hydrophobic additive.

[0161] Cellulosic materials with varying compositions of carrageenan (CAR), microfibrillated cellulosic material (MCM), micronized cellulose fibers (FCM), and glycerol (GOL) were produced, ranging from 5 to 30% w / w, 10 to 40% w / w, 5 to 20% w / w, and 20 to 50% w / w, respectively. The resulting products had a smooth and flexible texture to the touch and were visually opaque (above 80% opacity, ISO 2471), as shown in Figure 4. Their robustness and elasticity were also verified through density values ​​above 1.0 g / cm³. 3 , basis weight above 200 g / m² 2, tensile strength above 8 MPa and deformation between 25% and 40%. Its hydrophobic behavior and thermal stability were proven from the results of the contact angle with water, above 80°, and thermogravimetric degradation (30% mass loss) above 180 °C, respectively.

[0162] SEM images showed that the cellulosic-based materials have smooth and uniform surfaces.

[0163] During biodegradability tests according to ISO 23517:2021, the cellulosic-based materials showed complete disintegration and biodegradation of over 90% of the initial mass, proving their compostability profile. Three illustrative cellulosic-based materials from formulations with different mass ratios are presented below.

[0164] Aqueous formulations composed of carrageenan (CAR), microfibrillated cellulosic material (MCM), micronized cellulose fibers (FCM), and glycerol (GOL) were considered according to the following mass ratios (Table 1):

[0165] Table 1. Mass ratio of the aqueous formulations of Example 1.

[0166] Formulation: Mass ratio, % m / m

[0167] CAR: MCM: FCM: GOL: H20

[0168] A 0.75: 1: 0.5: 2: 95.75

[0169] B 0.25:1:0.25:1:97.5

[0170] C 0, 25: 0, 5: 0, 25: 1: 97

[0171]

[0172] The cellulose-based material was prepared according to the following steps:

[0173] a) all components were mixed to form the aqueous formulation;

[0174] b) The formulation resulting from step a) was stirred at 1000 rpm at room temperature for 6 hours until complete and uniform dispersion of all compounds in the formulation and formation of a hydrogel;

[0175] c) The hydrogel resulting from step b) was distributed into molds that were then dried in an oven at 35°C with ventilation until the formation of the cellulosic base material. The resulting cellulosic base materials had a w / w % composition of (Table 2):

[0176] Table 2. Compositions of the cellulosic base materials of Example 1.

[0177] Composition* of the cellulose base material, % w / w

[0178] CAR / MCM / FCM / GOL

[0179] A' 10, 2 / 13, 6 / 6, 8 / 27, 3

[0180] B' 6, 3 / 25, 5 / 6, 3 / 25, 2

[0181] C 7, 3 / 14, 5 / 7, 3 / 29, 0

[0182]

[0183] * The total percentage of the cellulose-based material is made up of a percentage of water that is acquired in equilibrium with the ambient relative humidity (RH) (in the case of these examples, 50% RH at 23°C for 24h).

[0184] Example 2 - with the use of a crosslinking agent and without the use of a hydrophobic additive.

[0185] Cellulose-based materials were produced with varying compositions of carrageenan (CAR), microfibrillated cellulosic material (MCM), micronized cellulose fibers (FCM), and glycerol (GOL) in the ranges of Example 1, and additionally with the crosslinking agent potassium chloride in varying amounts between 0.25 and 2% w / w. The products obtained had a smooth and flexible texture to the touch and were visually opaque (above 80% opacity, ISO 2471), as shown in Figure 5. In terms of robustness, the differences in basis weight and density between the cellulosic-based materials of this example compared to the cellulosic-based materials of Example 1 were not considered significant. Regarding tensile deformation, values ​​between 20% and 35% were obtained, lower than the values ​​obtained in example 1, due to the presence of the crosslinking agent which makes cellulosic-based materials less elastic.Its hydrophobic behavior was proven by the results of the contact angle with water, above 80°, and shows improvements compared to the cellulosic-based materials of example 1. Its thermal stability was verified with thermogravimetric degradation values ​​(30% mass loss) above 185°C.

[0186] SEM images showed that cellulosic-based materials have smooth and uniform surfaces.

[0187] During biodegradability tests according to ISO 23517: 2021, the cellulosic-based materials showed complete disintegration and biodegradation of over 90% of the initial mass, proving their compostability profile.

[0188] Three illustrative examples of this type of cellulosic-based material are presented below.

[0189] An aqueous formulation consisting of carrageenan (CAR), microfibrillated cellulosic material (MCM), micronized cellulose fibers (FCM), and glycerol (GOL) was considered, according to the following mass ratios (Table 3):

[0190] Table 3. Mass ratio of the aqueous formulations of Example 2.

[0191] Formulation: Mass ratio, % m / m

[0192] CAR: MCM: FCM: GOL: H20

[0193] D 0.75: 1: 0.5: 2: 93.75

[0194] E 0, 25: 1: 0, 25: 1: 95, 5

[0195] F 0.25:0.5:0.25:1:95.0

[0196]

[0197] The cellulose-based material was prepared according to the following steps:

[0198] a) All components were mixed, except for the crosslinking agent, to form the aqueous formulation;

[0199] b) The formulation resulting from step a) was stirred at 1000 rpm at room temperature for 6 hours until complete and uniform dispersion of all compounds in the formulation and formation of a hydrogel;

[0200] c) The hydrogel formed in step b) was distributed into molds and sprayed with the crosslinking agent, a 2% (w / v) potassium chloride solution, at room temperature (2g of solution for every 100g of final formulation, which corresponded to a mass ratio of 0.04% w / w in relation to the final formulation). Ex: for a 500g formulation, 490g of the mixture was poured and subsequently sprayed with 10g (~10mL) of 2% (w / v) potassium chloride solution;

[0201] d) The molds were then dried in an oven at 35°C with ventilation until the cellulose-based material was formed.

[0202] The resulting cellulosic-based materials had a w / w % composition of (Table 4):

[0203] Table 4. Compositions of the cellulosic-based materials of Example 2.

[0204] Composition* of the cellulose base material, % w / w

[0205] CAR / MCM / FCM / GOL / KCL

[0206] D' 10, 1 / 13, 5 / 6, 8 / 27, 0 / 0, 5

[0207] E' 6, 5 / 26, 0 / 6, 5 / 26, 0 / 1, 0

[0208] F' 7, 0 / 14, 0 / 7, 0 / 27, 9 / 1, 1

[0209]

[0210] * The total percentage of the cellulose-based material is made up of a percentage of water that is acquired in equilibrium with the ambient relative humidity (RH) (in the case of these examples, 50% RH at 23°C for 24h).

[0211] Example 3 - with the use of a crosslinking agent and with the use of a hydrophobic additive.

[0212] Cellulosic-based materials were produced with varying compositions of carrageenan (CAR), microfibrillated cellulosic material (MCM), micronized cellulose fibers (FCM), and glycerol (GOL) in the ranges of Example 1, and additionally with the crosslinking agent potassium chloride and the hydrophobic additive AKD in varying amounts between 0.25 and 2% w / m and 0.25 and 5% w / m, respectively. The products obtained had a smooth and flexible texture to the touch and were visually opaque (above 80% opacity, ISO 2471), as shown in Figure 6. In terms of robustness, the differences in basis weight and density between the cellulosic-based materials of this example compared to the cellulosic-based materials of Examples 1 and 2 were not considered significant.Regarding tensile deformation, values ​​between 20% and 30% were obtained, lower than the values ​​obtained in examples 1 and 2, due to the presence of the crosslinking agent and the hydrophobic additive, which makes the cellulosic-based materials more robust and less elastic. Their hydrophobic behavior was confirmed by the results of the contact angle with water, above 85°, and showed improvements compared to the cellulosic-based materials of example 2. Their thermal stability was verified with thermogravimetric degradation values ​​(30% mass loss) above 190 °C. SEM images showed that the cellulosic-based materials presented smooth and uniform surfaces.

[0213] During biodegradability tests according to ISO 23517: 2021, the cellulosic-based materials showed complete disintegration and biodegradation of over 90% of the initial mass, proving their compostability profile.

[0214] Three illustrative examples of this type of cellulosic-based material are presented below.

[0215] A formulation consisting of carrageenan (CAR), microfibrillated cellulosic material (MCM), micronized cellulose fibers (FCM), glycerol (GOL), and AKD was considered, according to the following mass ratios (Table 5):

[0216] Table 5. Mass ratio of the aqueous formulations of Example 3.

[0217] Formulation: Mass ratio, % m / m

[0218] CAR: MCM: FCM: GOL: AKD: H20

[0219] G 0.75:1:0.5:2:0.075:93.675

[0220] H 0.25:1:0.25:1:0.051:95.449

[0221] I 0.25:0.5:0.25:1:0.038

[0222]

[0223] The cellulose-based material was prepared according to the following steps:

[0224] a) All components were mixed, except for the crosslinking agent, to form the aqueous formulation;

[0225] b) The formulation resulting from step a) was stirred at 1000 rpm at room temperature for 6 hours until complete and uniform dispersion of all compounds in the formulation and formation of a hydrogel;

[0226] c) The hydrogel formed in step b) was distributed into molds and sprayed with the crosslinking agent, a 2% (w / v) potassium chloride solution, at room temperature (2g of solution for every 100g of final formulation, which corresponded to a mass ratio of 0.04% w / w in relation to the final formulation). Ex: for a 500g formulation, 490g of the mixture was poured and subsequently sprayed with 10g (~10mL) of 2% (w / v) potassium chloride solution;

[0227] d) The molds were then dried in an oven at 35°C with ventilation until the formation of the cellulose-based material.

[0228] The resulting cellulosic-based materials had a w / w % composition of (Table 6):

[0229] Table 6. Compositions of the cellulosic materials of Example 3.

[0230] Composition* of the cellulose base material, % w / w CAR / MCM / FCM / GOL / KCL / AKD

[0231] G' 10, 0 / 13, 3 / 6, 6 / 26, 6 / 0, 5 / 1, 0

[0232] H' 6, 4 / 25, 5 / 6, 4 / 25, 5 / 1, 0 / 1, 3

[0233] I' 6, 3 / 12, 5 / 6, 3 / 25, 0 / 1, 0 / 1, 0

[0234]

[0235] * The total percentage of the cellulose-based material is made up of a percentage of water that is acquired in equilibrium with the ambient relative humidity (RH) (in the case of these examples, 50% RH at 23°C for 24h).

[0236] Example 4 - with the use of a hydrophobic additive and without the use of a crosslinking agent.

[0237] Cellulosic materials with varying compositions of carrageenan (CAR), microfibrillated cellulosic material (MCM), micronized cellulose fibers (FCM), and glycerol (GOL) were produced in the ranges of Example 1 and, additionally, with the hydrophobic additive AKD in varying amounts between 0.25 and 5% w / w. The products obtained were in line with the previous examples, i.e., with a smooth and flexible texture and visually opaque (above 80% opacity, ISO 2471). In terms of robustness and mechanical performance, the differences in basis weight, density, strength, and tensile deformation between the cellulosic-based materials of this example compared to the cellulosic-based materials of Examples 1, 2, and 3 were not considered significant. Its hydrophobic behavior was proven by the results of the contact angle with water, in line with the cellulosic-based materials of all previous examples.Its thermal stability was verified with thermogravimetric degradation values ​​(30% mass loss) also in line with the cellulosic-based materials of all previous examples.

[0238] During biodegradability tests according to ISO 23517: 2021, the cellulosic-based materials showed complete disintegration and biodegradation of over 90% of the initial mass, proving their compostability profile.

[0239] Three illustrative examples of this type of cellulosic-based material are presented below.

[0240] A formulation consisting of carrageenan (CAR), microfibrillated cellulosic material (MCM), micronized cellulose fibers (FCM), glycerol (GOL), and AKD was considered according to the following mass ratios (Table 7) Table 7. Mass ratio of the aqueous formulations of Example 4.

[0241] Formulation: Mass ratio, % m / m

[0242] CAR: MCM: FCM: GOL: AKD: H20

[0243] J 0.75:1:0.5:2:0.075:95.675

[0244] K 0.25:1:0.25:1:0.051:97.449

[0245] L 0.25:0.5:0.25:1:0.038:97.962

[0246]

[0247] The cellulose-based material was prepared according to the following steps:

[0248] a) All components were mixed to form the aqueous formulation;

[0249] b) The formulation resulting from step a) was stirred at 1000 rpm at room temperature for 6 hours until complete and uniform dispersion of all compounds in the formulation and formation of a hydrogel;

[0250] c) The hydrogel resulting from step b) was distributed into molds that were then dried in an oven at 35°C with ventilation until the formation of the cellulosic base material.

[0251] The resulting cellulosic-based materials had a w / w % composition of (Table 8):

[0252] Table 8. Compositions of the cellulosic-based materials of Example 4.

[0253] Composition* of the cellulose base material, % w / w CAR / MCM / FCM / GOL / AKD

[0254] J' 15, 8 / 21, 0 / 10, 5 / 42, 0 / 1, 6

[0255] K' 8, 9 / 35, 6 / 8, 9 / 35, 6 / 1, 8

[0256] L' 11, 2 / 22, 3 / 11, 2 / 44, 6 / 1, 7

[0257]

[0258] * The total percentage of the cellulose-based material is made up of a percentage of water that is acquired in equilibrium with the ambient relative humidity (RH) (in the case of these examples, 50% RH at 23°C for 24h).

[0259] Characterization of the examples

[0260] Grammage and Density

[0261] Table 9 presents the results for basis weight and density of the different examples.

[0262] Table 9. Grammage and density values ​​for the different examples.

[0263] Example Product Density Grammage (g / m³) 2 )

[0264] (g / cm 3 ) A' 449.8 ± 2.7 1.153 ± 0.003 1 B' 266.4 ± 1.9 1.184 ± 0.035 C 233.3 ± 10.8 1.131 ± 0.014 D' 435.8 ± 0.8 1.114 ± 0.037 2 E' 251.3 ± 13.3 1.105 ± 0.017 F' 233.0 ± 1.6 1.089 ± 0.0 G' 448.2 ± 1.1 1.110 ± 0.002 3 H' 273.5 ± 0.7 1.130 ± 0.001 I' 311.6 ± 3.5 1.154 ± 0.047

[0265]

[0266] The cellulosic-based materials resulting from example 1 (A', B' and C') proved to be robust according to density values ​​above ~1.0 g / cm³. 3 and a basis weight between 230 - 450 g / m² 2 .

[0267] For examples 2 (D', E' and F'), example 3 (G', H' and I') and example 4 (J', K' and L'), the differences in basis weight and density between the cellulosic base materials without KC1, with AKD and with KC1 and AKD were not considered significant. The basis weight and density of the cellulosic base materials of the present invention can be adjusted and optimized according to the requirements of the intended application, through the amount of formulation and the mold used in the drying step.

[0268] Contact angles

[0269] Table 10 presents the results for contact angles of the different examples and commercial samples used as a reference.

[0270] Table 10. Contact angle values ​​for the different examples and for commercial samples.

[0271] Example Product O c. ultrapure water ( ) A' 80.3 ± 4.4 1 B' 81.0 ± 5.8

[0272] C 78.0 ± 9.0 D' 86.7 ± 4.9 2 E' 81.9 ± 5.4

[0273] F' 87.5 ± 5.7 G' 85.8 ± 4.6 3 H' 88.7 ± 5.3

[0274] I ' 95.4 ± 5.2 PU synthetic leather 72.1 ± 18.3 Animal leather - uncoated 95.5 ± 6.4 Animal leather - PU coated 89.4 ± 3.2

[0275]

[0276] The cellulosic-based materials resulting from example 1 (A', B' and C') showed contact angle values ​​with water between 78 and 81°, stable during the 150 s measurement, demonstrating a low absorption / penetration rate of the liquid. The cellulosic-based materials resulting from example 2 (D', E' and F') showed contact angle values ​​with water between 82 and 88°, stable during the 150 s measurement, demonstrating a greater hydrophobic character and a lower absorption / penetration rate of the liquid than the cellulosic-based materials of example 1, due to the presence of the crosslinking agent KC1.

[0277] The resulting cellulosic-based materials from example 3 (G', H' el') showed water contact angle values ​​between 86 and 95°, stable during the 150 s measurement, demonstrating an even greater hydrophobic character and an even lower absorption / penetration rate of the liquid than the cellulosic-based materials from example 2, due to the presence of the hydrophobic additive, AKD.

[0278] The cellulosic-based materials resulting from example 4 (J', K' and L') showed intermediate water contact angle values ​​compared to examples 2 and 3, stable during the 150 s measurement, also demonstrating hydrophobic character and a low absorption / penetration rate of the liquid in the cellulosic-based materials, due to the presence of the hydrophobic additive, AKD.

[0279] The water contact angle results obtained from the cellulosic-based materials of Examples 1 to 4 are within the range of values ​​(72 - 96°) presented by the products available on the market and used as a reference. Thus, the cellulosic materials of the present invention exhibit performance comparable to the reference products analyzed. Mechanical tests

[0280] Table 11 presents the results for tensile strength and tensile strain of the different examples and commercial samples used as a reference.

[0281] Table 11. Tensile strength and tensile strain values ​​for the different examples and for commercial samples.

[0282] Resistance to Deformation - Example Product

[0283] Tensile strength (MPa) Tensile strength (%) A' 7.9 ± 0.6 37.8 ± 1.5 1 B' 13.8 ± 0.9 26.0 ± 1.4 C 9.0 ± 0.7 28.4 ± 1.9 D' ​​8.9 ± 0.9 33.0 ± 3.3 2 E' 12.8 ± 2.9 22.0 ± 6.4 F' 8.5 ± 0.5 26.0 ± 3.3 G' 10.1 ± 1.5 28.5 ± 2.4 3 H' 12.5 ± 0.8 21.7 ± 2.6 I ' 8.7 ± 0.3 28.9 ± 2.9 Animal leather not

[0284] 19.0 ± 2.7 38.4 ± 3.7 coated

[0285] Animal leather

[0286] 14.1 ± 1.4 70.7 ± 7.0 coated with PU

[0287]

[0288] The resulting cellulosic-based materials from examples 1, 2, and 3 showed tensile strength and strain values ​​that directly depend on their final composition, namely the total percentage of MCM and FCM and the total percentage of CAR and GOL. In cellulosic-based materials where the total percentage of MCM and FCM is higher, greater tensile strength was observed (cellulosic-based materials B', E', H') and less tensile strain; that is, cellulosic-based materials are more robust and less elastic. Conversely, in cellulosic-based materials where the percentage of CAR and GOL is higher, lower tensile strength values ​​and a higher percentage of strain were observed; that is, cellulosic-based materials are more elastic and require less force to rupture.

[0289] Additionally, with the consecutive addition of KC1 and AKD, the tensile deformation percentages decreased, meaning the cellulosic-based materials became less elastic.

[0290] The tensile strength values ​​obtained for the cellulosic-based materials are in line with the values ​​observed for the commercial samples.

[0291] TGA Table 12 presents the results for the temperatures corresponding to 10% and 30% mass loss (water) of the different examples and commercial samples used as a reference.

[0292] Table 12. Temperature values ​​corresponding to 10% and 30% mass loss (water) for the different examples and for commercial samples.

[0293] Example: 10% loss of 30% loss of Product mass (water) mass

[0294] °C °C

[0295] A' 103.8±2.6 204.5±0.8 1 B' 109.7±2.1 201.4±1.2 C 84.3±1.8 190.3±1.3 2 D' 95.2±0.4 202.4±2.4

[0296]

[0297] E' 140.6 ± 7.8 216.7 ± 8.3 F' 86.1 ± 1.8 189.3 ± 1.3 G' 118.9 ± 1.9 214.0 ± 0.9 3 H' 159.0 ± 2.7 233.6 ± 1.3 I' 84.0 ± 7.7 188.7 ± 1.3 PU synthetic leather 281.4 335.1 Animal leather - not coated 95.49 318.2

[0298] Animal leather - 87.95 314.5 coated with PU

[0299]

[0300] In this specific case, the references, made of or coated with fossil-based plastic polymers, showed high thermogravimetric degradation values ​​(30% mass loss) above 300 °C, demonstrating excellent thermal stability. In turn, the cellulosic-based materials resulting from examples 1 to 4, even those made solely of materials of natural origin, showed thermogravimetric degradation values ​​(30% mass loss) between 190 and 234 °C, which demonstrates the high thermal stability of the materials of the present invention.

[0301] Images WITHOUT

[0302] Table 13 presents the SEM images of the different examples and commercial samples used as a reference.

[0303] Product A' D' G'

[0304] Image ■■ At ■

[0305] NO AAÍlSut? y. ■■■■ »ú •^;.••■ '^"sí '?j '. ■K. f p'I Í||Í|; X'. / XAF" Product B' E' H'

[0306] Image

[0307] SEM ■M

[0308] Product C' F' I'

[0309] Image

[0310] WITHOUT

[0311] Commercial sample WITHOUT Image

[0312] PU synthetic leather

[0313] Wllllu Animal leather - uncoated lliiiB

[0314] Animal leather - PU coated

[0315]

[0316] SEM images showed smooth and uniform surfaces for all cellulosic-based materials from the different examples.

[0317] The references presented different types of surfaces according to their nature and treatments. PU synthetic leather proved to be extremely soft, like pure plastic. Animal leather presented pores and imperfections that are reduced after PU coating.

[0318] Elementary Analysis

[0319] Table 14 presents the results for the elemental analysis of the different examples.

[0320] Table 14. Elemental analysis values ​​for the different examples.

[0321] Examples Product N / C / H (%, dry mass) 1 A' 0.36 / 39.9 / 6.2

[0322] B' 0.38 / 42.2 / 6.3

[0323] C 0, 35 / 41, 1 / 6, 1

[0324] 2 D' 0, 31 / 39, 7 / 6, 0

[0325] E ' 0, 33 / 41, 3 / 6, 1

[0326] F' 0, 31 / 39, 2 / 5, 8

[0327] 3 G' 0, 33 / 39, 5 / 6, 1

[0328] H' 0, 33 / 42, 1 / 6, 2

[0329] I ' 0, 33 / 41, 2 / 6, 0

[0330]

[0331] All the cellulosic-based materials from the different examples showed a percentage of ~40% carbon and ~0.35% nitrogen, which corresponds to a C / N ratio of ~100:1, comparable with other compostable materials such as wood (100-500:1) or paper (150-200:1). Biodegradability / Compostability Tests

[0332] Compostability tests, according to ISO 23517: 2021, revealed complete disintegration and biodegradation of 95-100% of the initial mass of the cellulosic-based materials of the different examples shown (Figure 7).

[0333] PU and animal synthetic leathers, both uncoated and PU-coated, are not compostable or biodegradable according to ISO 23517:2021.

Claims

CLAIMS 1. Cellulosic-based material characterized by comprising 10-40% w / w of a microfibrillated cellulosic material, 5-20% w / w of micronized cellulose fibers, 5-30% w / w of at least one gelling agent and a further 20-50% w / w of at least one plasticizer.

2. Cellulose-based material according to claim 1, characterized by further comprising 0.25-2% w / w of at least one crosslinking agent.

3. Cellulose-based material according to claim 1 or 2, characterized by further comprising 0.25-5% w / w of at least one hydrophobic additive.

4. Cellulosic-based material according to claim 3, characterized by consisting of 6.4% w / w of at least one gelling agent, 25.5% w / w of microfibrillated cellulosic material, 6.4% w / w of micronized cellulose fibers, 25.5% w / w of at least one plasticizer, 1.0% w / w of at least one crosslinking agent and 1.3% w / w of at least one hydrophobic additive, the remaining percentage being water.

5. Cellulose-based material according to any of the preceding claims, characterized in that the microfibrillated cellulosic material is selected from the group consisting of microfibrillated Kraft pulp cellulosic material, high-yield microfibrillated Kraft pulp cellulosic material, unbleached microfibrillated Kraft pulp cellulosic material, bleached microfibrillated Kraft pulp cellulosic material, semi-bleached microfibrillated Kraft pulp cellulosic material, sulfite pulp cellulosic material, unbleached microfibrillated sulfite pulp cellulosic material, bleached microfibrillated sulfite pulp cellulosic material, microfibrillated Kraft pulp cellulosic material Semi-bleached sulfite cellulosic film and its combinations.

6. Cellulose-based material according to any of the preceding claims, characterized in that the micronized cellulose fibers are selected from the group consisting of micronized cellulose fibers from Kraft pulp, high-yield micronized cellulose fibers from Kraft pulp, unbleached micronized cellulose fibers from Kraft pulp, bleached micronized cellulose fibers from Kraft pulp, semi-bleached micronized cellulose fibers from Kraft pulp, sulfite micronized cellulose fibers from sulfite pulp, unbleached micronized cellulose fibers from sulfite pulp, bleached micronized cellulose fibers from sulfite pulp, semi-bleached micronized cellulose fibers from sulfite pulp, and combinations thereof.

7. Cellulose-based material according to any of the preceding claims, characterized in that the Kraft cellulose pulps are eucalyptus Kraft cellulose pulps.

8. Cellulosic-based material according to any of the preceding claims, characterized in that the gelling agent is selected from the group consisting of alginates, carrageenans, galactans, agarans and combinations thereof.

9. Cellulosic-based material according to any of the preceding claims, characterized in that the plasticizer is selected from the group consisting of polyvinyl alcohol, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, glycerol, sorbitol, polyols and combinations thereof.

10. Cellulosic-based material according to any one of claims 2 to 9, characterized in that the crosslinking agent is selected from the group consisting of zinc chloride, magnesium chloride, calcium chloride, potassium chloride, aluminum trichloride, iron chloride, aluminum sulfate, copper sulfate, nickel sulfate, epichlorohydrin, glutaraldehyde, citric acid and combinations thereof.

11. Cellulosic-based material according to any one of claims 3 to 10, characterized in that the hydrophobic additive is selected from the group consisting of alkyl ketene dimer, alkenyl succinic anhydride, oils, waxes, resins, rosin and combinations thereof.

12. Cellulosic-based material according to any one of claims 3 to 11, characterized in that the gelling agent is carrageenan, the plasticizer is glycerol, the crosslinking agent is potassium chloride, and the hydrophobic additive is alkyl ketene dimer.

13. A process for producing the cellulosic-based material claimed in any one of claims 1 to 12, characterized by comprising the following steps: a) preparation of an aqueous formulation comprising 0.5-2% w / w of a microfibrillated cellulosic material, 0.25-1% w / w of micronized cellulose fibers, 0.25-1.5% w / w of at least one gelling agent and 0.75-2.5% w / w of at least one plasticizer; b) stirring the resulting formulation from step a) at room temperature until a hydrogel is formed; c) dispensing the hydrogel resulting from step b) into molds; d) drying the hydrogel resulting from step c) at a temperature between 30°C-80°C until the formation of the cellulosic base material.

14. Process according to claim 13, characterized by further comprising, after step c) and before step d), a spraying step of the hydrogel with a solution of at least one crosslinking agent at a mass ratio of 0.02 to 0.08% w / w relative to the aqueous formulation.

15. Process according to claim 13, characterized in that the formulation of step a) further comprises 0.015-0.225% w / w of at least one hydrophobic additive.

16. Process according to claim 13, characterized in that the formulation of step a) further comprises 0.015-0.225% w / w of at least one hydrophobic additive and after step c) and before step d) there is also a spraying step of the hydrogel with a solution of at least one crosslinking agent at a mass ratio of 0.02 to 0.08% w / w relative to the aqueous formulation.

Images