Plant-based leather-like material made from persimmon puree

Abstract

The present invention relates to a vegan, reusable leather-type material that is at least 50%, preferably at least 80%, biobased and plant-based. The material is based on a composition containing a polymer derived from persimmon (Diospyros kaki) mass fraction and a plant-based polyol. The invention also discloses a process for obtaining the material. The leather-type material can be used in a variety of textile products, including clothing, footwear, and accessories. This material has been proven to maintain the same mechanical properties as animal-based or synthetic leather, making it a sustainable alternative and contributing to a circular economy. This sustainable plant-based leather-type material has a lower environmental impact and is an alternative to known leathers.

Description

[Technical Field]

[0001] The present invention relates to the provision of a natural, eco-friendly, vegan and reusable leather-type material of plant origin, which can be used in a variety of products in the textile sector as an alternative to leather of animal or synthetic origin. [Background technology]

[0002] People have been using materials derived from animal skin for a long time. This material is preferred due to its strength, flexibility, durability, and attractive appearance. Animal skin can be applied to various types of consumer products, such as clothing, furniture, car interiors, and many other retail products. Often, the issues related to animal skin production are related to environmental, health, or social issues (Sivaram and Barik, 2019. Energy from toxic organic waste for heat and power generation. Chapter 5. Woodhead Publishing Series in Energy. Pages 55-67). The production of animals used as raw materials for leather production requires a lot of water, energy, and land, and livestock production generates large amounts of greenhouse gases (CO2 and NH4). The production of animal skin also requires a large mixture of chemicals (such as dyes derived from chromium salts and heavy metals), which have environmental impacts due to their water demands, potential for pollution, and toxic and carcinogenic properties that can be harmful to human health and the environment if sprayed.

[0003] The use of animal skin and fur has also become a social concern. Many people oppose the use of animal skin and fur because they consider it unethical. In response to growing demands to end the use of animal skin, alternative substitutes must be found. One option considered more environmentally friendly is synthetic leather. Recent concerns about sustainability in all areas of industrial production have provided a compelling rationale for promoting the use of natural materials and replacing non-renewable fossil-derived raw materials. While leather is bio-based and renewable, these considerations have not led to a resurgence. Instead, leather has come under even more pressure due to ongoing debates regarding greenhouse gas emissions from cattle farming, the sustainability of leather production, and animal welfare. At the same time, an increasing number of people are consciously seeking to eliminate meat or any products of animal origin. All of these needs pose new challenges for cultural and material development.

[0004] Vegan leather refers to leather that does not involve any animal material in any part of the production process. This type of leather is usually imitation leather, or synthetic leather. While it is vegan because it is not derived from animals, it is not environmentally friendly because it contains plastic. This synthetic leather material is usually made from polyvinyl chloride (PVC) and polyurethane, a petroleum-based product. While synthetic leather may offer a solution to the problems of the animal skin production process, PVC-based synthetic materials do not solve the environmental issues. Petroleum-based raw materials are not sustainable, and the production process uses additional chemicals, such as plasticizers, to make the synthetic leather more resilient. Furthermore, leather tanning also has a significant environmental impact. None of the vegan leathers created to date are fully biodegradable. This is because the respective materials are made from a blend of plants and polyurethane, or are plant-based but coated with a plastic-based resin. There is a need for environmentally friendly leather alternatives that have an appealing appearance to consumers.

[0005] Vegetable-based leather is an alternative to animal leather, produced from different components and waste materials, always of plant origin. This makes it the most sustainable alternative to traditional animal skin, surpassing other commercial and synthetic materials. Vegetable-based leathers include mushrooms, pineapple, paper, wax cotton, teak leaves, apple fiber, grapes, kombucha tea, corn, cereals, coconut, hemp, white nettle, and cork. However, leathers made from these plants usually contain synthetic materials. However, to improve structural characteristics and create a more appealing appearance for consumers, these leathers usually contain synthetic polymeric components, such as polyurethane.

[0006] A circular economy is an economic system that aims to eliminate waste and maintain the continuous use of resources. A circular system employs the basic principles of reuse, share, repair, share, remanufacture, and recycle to create a closed-loop system, thereby minimizing use or resource inputs and reducing waste production, pollution, and carbon emissions. It is estimated that one-third of food intended for human consumption worldwide is lost or wasted, amounting to 1.3 billion tons per year. Food loss and waste have become a major concern in recent years. For this reason, the United Nations' 2030 Agenda for Sustainable Development reflects greater awareness of the issue and proposes measures by businesses to reduce food waste.

[0007] Although leather products produced from vegetable sources are a natural alternative to synthetic and animal-based leathers, they are usually obtained from crops specially grown for this purpose, which is not sustainable and may even have an impact on the natural environment.

[0008] Spain is Europe's most important persimmon-growing country, with a total area of ​​18,601 hectares and a production of 492,320 tons. Currently, Spain is the second largest persimmon producer in the world, accounting for 10.4% of total persimmon production. According to 2017 data from the Spanish Ministry of Agriculture, persimmons are cultivated on 15,931 hectares in the Valencian Community, accounting for 86% of the country's land area and 384,785 tons, or 95% of Spain's total production. In less than 10 years, the area cultivated with persimmons in the Valencian Community has increased sixfold, from 2,000 to over 13,000 hectares. The "Ribera del Xuquer" persimmon is the only persimmon in the world recognized and granted the Protected Designation of Origin (Persimmon®) due to its exceptional characteristics and growing region. Unfortunately, due to market demand and the possible presence of pests and diseases, almost half of the harvest is wasted each year. Total weight and economic losses for persimmon growers were estimated to be an average of 29.5% (referring to total production) or 38.5% (referring to kilograms ultimately marketed). Thus, millions of kilograms of edible persimmons are wasted each year.

[0009] There is a need in the art for leather that is of plant origin, biodegradable, natural, eco-friendly, compostable, vegan and reusable, free of synthetic materials and forms part of a circular economy in the region of origin of the starting material. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention discloses a vegan leather-type material of plant origin containing persimmon. The invention is being developed as part of a circular economy project developed at the University of Valencia Science Park (Spain). Persimmon residue and discarded specimens are reused in the production of leather. The process disclosed herein leaves no residue.

[0011] In a first aspect, the present invention refers to a composition for vegan leather comprising a polymer derived from persimmon (Diospyros kaki) and a polyol of plant origin. In a preferred embodiment, the persimmon may be selected from the Bright Red ("Rojo Brigante") or Triumph varieties. In a more preferred embodiment, the component is the persimmon variety Bright Red ("Rojo Brigante").

[0012] The persimmon mass of the composition of the present invention is selected from persimmon extract, persimmon puree, persimmon pulp, or a combination thereof. In a preferred embodiment, the persimmon mass is persimmon puree or persimmon extract. The puree may be obtained by blending and crushing fruits by any method known in the prior art. The persimmon extract may be the result of Soxhlet extraction of persimmon fruits. The fruit pieces or persimmon puree may be frozen after step a). In one embodiment, the persimmon mass is directly incorporated into the process without being frozen.

[0013] Leather is generally defined as animal skin that has been treated to preserve it for use in the manufacture of products such as clothing, shoes, etc. For the purposes of the present invention, the expressions "leather-type material" or "vegan leather" refer to a product that is similar to leather of animal origin and can be used to manufacture the same consumer goods as leather. Plant or vegan origin refers to biologically-derived raw materials with a high biological predominance (organic materials that are plants or are produced directly by the physiological activity of plants, rather than other elements such as fossil gas, coal, or petroleum).

[0014] In the present invention, the term "bio-based" is also used, which can refer to a naturally occurring or synthetic product that consists primarily of a substance or substances obtained from biological resources (biomass), or to a product made by a process that uses biomass. Bio-based materials are recognized as potentially more environmentally friendly alternatives to their petroleum-derived counterparts (U.S. Environmental Protection Agency, EPA). The term has become so widespread that, in fact, there is an international labeling system that classifies materials as bio-based according to the percentage of renewable raw materials (% Bio-based). Any component is 100% bio-based if it is 100% or of plant origin. A detailed definition of bio-based products can be found at https: / / single-market-economy.ec.europa.eu / sectors / biotechnology / bio-based-products_en.

[0015] Preferably, the composition comprises 20-60% by weight of the persimmon and / or the polymer represents 40-80% by weight of the total weight of the composition, more preferably 30-40% by weight of the persimmon and / or the polymer represents 60-70% by weight of the total weight of the composition.

[0016] In one embodiment, the composition of the present invention comprises persimmon and a plasticized starch derived from a starch and a polyol of plant origin. The starch is selected from the group consisting of corn, tapioca, potato, or a combination thereof, preferably corn starch. The polyol is selected from the group consisting of glycerol, erythritol, ribitol, and xylitol, preferably glycerol.

[0017] In another embodiment, the composition of the present invention comprises persimmon and a polymer that is a polyurethane derived from a vegetable polyol.

[0018] In the present invention, the term "vegetable polyol-derived polyurethane or PU" refers to a PU obtained by reacting a polyisocyanate with a polyol based on a vegetable oil, such as soybean oil, safflower oil, cotton oil, linseed oil, peanut oil, olive oil, sunflower oil, canola oil, rapeseed oil, corn oil, palm oil, or a combination thereof. Non-limiting examples of said PUs can be found in U.S. Patent No. 20060276609(A1), and non-limiting examples of vegetable oil-based polyols can be found in U.S. Patent No. 7786239(B2).

[0019] In a preferred embodiment, the present invention provides a composition of a vegan leather-type material of vegetable origin comprising: 40-60% persimmon Red Brilliant ('Rojo Brigante'); 10-40 w / w% cornstarch, and 2-20% w / w% glycerol.

[0020] In a more preferred embodiment, the material comprises about 59 w / w% Red Brilliant (Rojo Brigante) persimmon, about 27 w / w% cornstarch, and about 14% glycerol. The term "about" should be interpreted as a margin of error of ±2 w / w%.

[0021] The composition may further comprise a plant-derived dye. The dye imparts the desired color to the final product. In a preferred embodiment, the dye is present in an amount of 1-2% by weight based on the total weight of the composition. In a preferred embodiment, the amount of dye is 0.1-1% by weight. The dye may be selected from any plant-derived dye, such as dyes derived from catechu tree, gamboge resin, chestnut shell, Himalayan rhubarb, Indigofera leaves, Kamara seed pods, Madder root, mangosteen peel, Myrobalan fruit, pomegranate peel, teak leaf, weld grass, or charcoal. In a preferred embodiment, the dye is charcoal.

[0022] In a preferred embodiment, the composition of the present invention further comprises from 1 to 10% by weight, relative to the total weight of the composition, of a vegetable oil selected from sesame oil, canola oil, sunflower oil, soybean oil, peanut oil, olive oil, corn oil, bean oil, grape seed oil, jojoba oil, palm oil, cottonseed oil, almond oil, safflower oil, walnut oil, avocado oil, rice bran oil, and linseed oil.

[0023] In another preferred embodiment, the composition of the present invention further comprises from 0.5 to 2% by weight, relative to the total weight of the composition, of an additive selected from thickeners, crosslinkers, stabilizers, which additives are generally known to those skilled in the polymer field.

[0024] Another aspect of the present invention refers to a vegan leather material comprising a persimmon-based composition as described above.

[0025] In a preferred embodiment, the material is a layered material comprising the following layers: a) a top layer comprising a water-based polyurethane; b) a second layer comprising the composition according to any one of claims 1 to 9; c) a third layer comprising a water-based polyurethane having adhesive properties; and d) optionally a fourth layer which is a fabric layer.

[0026] The aqueous polyurethanes used to obtain the layered materials of the present invention can be any known in the art. They may be used in the form of a dispersion, a two-component colloidal system in which polyurethane particles are dispersed in a continuous aqueous medium. The concept of producing aqueous polyurethanes is directed toward producing polymers with a high number of hydrophilic groups to achieve water solubility. These characteristics of aqueous polyurethanes make them highly suitable for a wide range of applications. These environmentally friendly polymers are non-toxic, non-flammable, and do not pollute the air or generate wastewater. Because only water evaporates during the process, these systems are not harmful to the environment. Aqueous polyurethanes are important in many industrial applications, including coatings, adhesives, ink binders, fiberglass, paper sizing agents, synthetic leather, biomaterials, membranes and packaging films, and waterproof textiles.

[0027] In another preferred embodiment, layer (a) represents 10 to 20% by weight relative to the total weight of the material, and / or layer (b) represents 20 to 70% by weight relative to the total weight of the material, and / or layer (c) represents 2 to 10% by weight relative to the total weight of the material, and / or layer (d) represents 30 to 50% by weight relative to the total weight of the material.

[0028] In another embodiment, the top layer (a) of the material is coated with a composition containing a wax and a vegetable oil, preferably in a 1:1 ratio. The wax may be selected from beeswax, carnauba wax, montan wax, or candelilla wax, and is preferably beeswax. The oil may be selected from any vegetable oil, such as sesame oil, canola oil, sunflower oil, soybean oil, peanut oil, olive oil, corn oil, soybean oil, grape seed oil, jojoba oil, palm oil, cottonseed oil, castor oil, almond oil, safflower oil, walnut oil, avocado oil, rice bran oil, and linseed oil. Preferably, the vegetable oil is olive oil.

[0029] The top layer (a) is formed from a water-based polyurethane and is deposited on the layer (b) of the persimmon-containing composition. In a preferred embodiment, the polyurethane comprises 10-20 wt. % of the total weight of the layered material, preferably about 17 wt. %. Preferably, the polyurethane layer is at least 45% bio-based.

[0030] The second layer (b) is formed from the aforementioned persimmon-containing composition, and can be adjusted by modifying the proportions of its components to vary the softness, flexibility, and mechanical resistance of the final material. This layer constitutes 20 to 70% by weight, preferably about 50% by weight, of the total weight of the layered material.

[0031] The third layer (c) is an adhesive layer positioned between the second layer (b) and the textile layer. In a preferred embodiment, the adhesive comprises 2-10 wt. % of the total weight of the layered material, preferably about 7.5 wt. %. Preferably, the adhesive layer is at least 50% bio-based. In a preferred embodiment, the adhesive is a water-based polyurethane adhesive. The polyurethane and adhesive may be any component (respectively, polyurethane or adhesive) that has a high percentage of bio-based materials and is solvent-free. Non-limiting examples of this polyurethane can be found in EP 2554559 B1.

[0032] The textile layer is preferably made from plant fibers and has a mechanical support function. This layer can be selected from any textile made of 100% plant origin, such as cotton, seeds, coconut, or linen. In a preferred embodiment, the textile layer is 100% cotton. The textile layer accounts for 30-50% by weight, preferably about 37% by weight, of the total weight of the layered material.

[0033] The layered material in this embodiment has a structure, from top to bottom, of polyurethane, persimmon-containing material, adhesive, and 100% fabric layer.

[0034] In a preferred embodiment, the width of each layer is as follows: layer (a) is 0.05-0.30 mm thick, and / or layer (b) is 0.20-1.50 mm thick, and / or layer (c) is 0.05-0.20 mm thick, and / or layer (d) is 0.20-0.50 mm thick. The width of the final material is approximately 0.6-2.5 mm. The term "approximately" is interpreted as a tolerance of ±2% of the above values.

[0035] The layered material should be at least 50% bio-based, preferably at least 80% bio-based, and more preferably at least 85% bio-based.

[0036] The leather-type materials of the present invention disclosed above all have similar appearance and mechanical characteristics to animal-origin or synthetic leather. The mechanical properties of the materials of the present invention, such as single-side tear strength, tensile strength, abrasion fastness, flexibility, and average thickness, are comparable to those of prior art leather materials, which means that the materials of the present invention are suitable for use as replacements for these materials. Demonstration of these properties is disclosed in the Examples.

[0037] In a third aspect, the present invention relates to a process for obtaining the aforementioned layered material, comprising the following steps: a) depositing a first layer of water-based polyurethane onto a substrate; b) drying the polyurethane of step a) at a temperature of 100-120°C for 1-10 minutes; c) adding a layer of the persimmon-containing composition to the dried polyurethane of step b); d) drying the two layers at a temperature of 70-150°C for 5 minutes to 2 hours; e) adding a third layer of water-based polyurethane with adhesive properties on the layer containing dried persimmons from step d), and optionally adding a textile layer on the adhesive layer from step e); f) drying at a temperature of 100 to 150°C for 1 to 5 minutes;

[0038] To imitate the appearance of leather on the top layer of the vegan leather material of the present invention, the support in step a) on which the first layer is deposited provides a pattern for imprinting the pattern on the top layer (a). This can be done using embossed paper that defines the surface design of the material. While any embossed paper can be used, embossed paper that imitates the appearance of leather of animal origin is preferred. Another option is to apply an iron bearing the desired pattern and press it onto the top layer to give it this imitation shape.

[0039] In embodiments in which the persimmon composition includes a starch-derived polymer, the starch is dissolved in distilled water and heated. In a preferred embodiment, the starch is in the form of starch granules. The solution is heated with constant stirring at 70-80°C until the starch is completely dissolved. It is important to disperse the starch molecules in the heated water to avoid crystallization due to gelatinization of the starch. The temperature range is important because temperatures between 70-80°C prevent starch degradation. The melting point of native starch is higher than its degradation temperature. At temperatures above this range, starch may lose equilibrium moisture within its granules and begin to degrade before dissolving. The starch may be selected from the group consisting of corn, tapioca, potato, or a combination thereof. In a preferred embodiment, the starch is cornstarch. In a more preferred embodiment, the starch is granular cornstarch. The amount of starch is 5 to 20% w / v, preferably 10 to 20% w / v, and more preferably 16% w / v, relative to the distilled water.

[0040] For the purposes of the present invention, the terms "thermoplastic starch," "plasticized starch," and "pseudo-thermoplastic starch" are synonymous and refer to a homogeneous material formed by gelatinized starch combined with a polyol. In a first step, a polyol, preferably of vegetable origin, is added to the gelatinized starch, and in a second step, the mixture is heated at 70-80°C with continuous stirring until a translucent gel phase is formed. The amount of polyol is 40-60% w / w of the amount of starch added in step b), preferably 50% w / w. In a preferred embodiment, the polyol is selected from the group consisting of glycerol, D-sorbitol, galactitol, mannitol, pinitol, arabitol, ribitol, erythritol, threitol, syritol, volemitol, perseitol, and meso-inositol. In a more preferred embodiment, the polyol is glycerol. The polyol forms hydrogen bonds with the starch molecules through the action of the hydroxyl groups on the starch molecules, increasing their mobility and causing the starch to exhibit plasticization. All starch granules must completely transform into a translucent gel phase to form pseudo-thermoplastic starch. In a preferred embodiment, the glycerol (CAS No. 56-81-5) in step c) is of vegetable origin. Glycerol can be obtained by heating coconut oil, soybean oil, or palm oil under pressure, which causes the glycerol to separate into water. The glycerol is then isolated by distillation. Glycerol can also be obtained as a by-product during soap or biodiesel production. Since glycerol is also a waste product from biodiesel production, using glycerol from this process also improves the sustainability of the process of the present invention (Gu Y and Jerome F, 2010. Green Chemistry 12:1127-38). Combining water and glycerol increases the flexibility of the material by increasing the intermolecular spacing and reducing the intramolecular hydrogen bonding along the starch polymer chains.

[0041] Next, 20-40% w / v of the persimmon mass fraction is incorporated into the thermoplastic starch of the process. In a preferred embodiment, the amount of persimmon mass added is 20-25% w / v. The mixture is stirred until a homogeneous substance or composite is formed. The persimmon mass fraction acts as a binder in the mixture to form the composite. The persimmon as a binder improves the rigidity of the material, preventing the polymer from becoming too brittle due to moisture loss, and also improves the thermoplastic properties of the starch. The combination is blended until completely homogenized.

[0042] In another embodiment, a plant-derived dye may be added in a previous step. The dye imparts the desired color to the final product. In a preferred embodiment, 0.1-1% w / v of the dye is added to the mixture. In a more preferred embodiment, the amount of dye is about 0.5% w / v of the mixture. The dye is selected from any plant-derived dye, such as dyes derived from catechu tree, gamboge resin, chestnut shell, Himalayan rhubarb, Indigofera leaves, Kamara seed pods, Madder root, mangosteen peel, Myrobalan fruit, pomegranate peel, teak leaf, weld grass, or charcoal. In a preferred embodiment, the dye is charcoal. Charcoal is a plant-based dye that is stable under high temperature, light, and pH conditions and can also impart antibacterial resistance to the leather obtained by the aforementioned process. Activated carbon, such as charcoal, remains stable at temperatures well above 900°C.

[0043] The homogenized composite material is then placed between a mold and a sheet of 100% cotton fiber material. The mold determines the design of the material. In this case, a mold that mimics the surface of animal origin may be used. The material is incorporated into the mold to form a layer of 3 to 10 mm. A sheet of 100% cotton fiber is placed on top of the layer of composite material. This sandwich structure undergoes a curing process, which involves placing the structure in an oven and heating it at 60 to 80°C, preferably about 70°C, for 1 to 20 hours, preferably 1.5 to 4 hours. After this curing step, the material is kept at room temperature for 12 to 24 hours. The cooling time at room temperature depends on the curing time of step e); the shorter the curing, the shorter the resting time. After the resting time has elapsed, the sheet-like material is removed from the mold to obtain a leather-like material. The size of this sheet of material depends on the size of the mold; after step e), the thickness is approximately 0.6 to 2.5 mm.

[0044] The composition of the homogenized composite material in step e) comprises 20-40 w / v% persimmon, 5-20 w / v% starch, 2-12 v / v% glycerol, and 28-73 v / v% water, percentages relative to the final amount of the homogenized composite material. In a preferred embodiment, the composition of the homogenized composite material in step e) comprises 20-25 w / v% persimmon, 7-15 w / v% starch, 3-6 v / v% glycerol, and 54-70 v / v% water, percentages relative to the final amount of the homogenized composite material. In a more preferred embodiment, the homogenized composite material also comprises 0.1-1% w / v of a dye of plant origin.

[0045] To coat the top layer of the layered material, the wax and oil are heated and mixed. This mixture is cooled at room temperature and applied to the material obtained in step e). The coated material is introduced into an oven and heated at 60-80°C, preferably 70°C, for 2-10 minutes. Additional coating layers may be added by repeating the same process described herein.

[0046] In another embodiment, the leather-type material is further enriched with bacterial or yeast cultures via SCOBY (Symbiotic Culture of Bacteria and Yeast). SCOBY is a biopolymer obtained from the fermentation of kombucha beverages, which are produced by fermenting tea (black / green tea) and sugar. A layer of SCOBY obtained after kombucha fermentation can be added to the dried leather or compound, or both, to form a composite material with enhanced properties. The cultures are added after step e) or to the composite material in step d).

[0047] In a preferred embodiment, the polyurethane in step a) is 10-20 w / w%, preferably about 17%, based on the total weight of the four-layer material. The polyurethane layer is preferably at least 45% bio-based. In a preferred embodiment, the polyurethane is a water-based polyurethane.

[0048] In a preferred embodiment, step b) is carried out at 100° C. for 2 minutes. In another preferred embodiment, step d) is carried out at 70° C. for 1 hour 30 minutes. In another preferred embodiment, step f) is carried out at 100° C. for 2 minutes.

[0049] The composition of the intermediate layer in step c) can be adjusted by modifying the percentages of its components to change the softness, flexibility, and mechanical resistance of the final four-layer material. This layer constitutes 20-70 w / w% of the total weight of the four-layer material. In a preferred embodiment, the adhesive in step e) is 2-10 w / w%, preferably about 7.5 w / w%, of the total weight of the four-layer material. The adhesive layer is preferably at least 50% bio-based. In a preferred embodiment, the adhesive is a water-based polyurethane adhesive. The polyurethane and adhesive can be any component (respectively, polyurethane or adhesive) that requires a high percentage of bio-based materials and is solvent-free.

[0050] The textile layer of step e) can be selected from any textile of 100% plant origin, such as cotton, seeds, coconut, linen, etc. In a preferred embodiment, the textile layer is 100% cotton. The textile layer accounts for 30-50 w / w%, preferably about 37 w / w%, of the total weight of the four-layer material.

[0051] In a fourth aspect, the present invention relates to an article comprising the above-mentioned vegan leather material. The article may be a textile product, footwear, leather goods, bookbinding, a frame, a bag, furniture, a watch strap, a cover, a bracelet, a handle, a basket, a key chain, or a mask. The leather of the present invention may be used in any object where leather of animal origin or synthetic leather is used.

[0052] In a fifth aspect, the present invention refers to the use of persimmon (Diospyros kaki) for the production of textiles, preferably vegan leather. The use of materials obtained from the persimmon fruit may be combined with the above-mentioned polymers to produce textiles with the same properties and aspects as true leather.

[0053] Although other leather-type materials of plant origin have been disclosed, the selection of persimmon is not without its inherent characteristics, which are not considered by those skilled in the art. Persimmons lack the ability to form a 3D matrix that provides the necessary strength and flexibility for the material due to the low number of fibers in their composition (approximately 1 w / w%). Furthermore, this fruit typically exhibits many surface defects due to variations in color, particle size, and a non-smooth surface. These characteristics discourage those skilled in the art from using persimmons over other plants. The leather-type material disclosed herein offers a low-environmental-impact alternative to known leathers and also contributes to a circular economy by utilizing surplus persimmons that do not reach consumer tables. The innovative new material of the present invention is designed to mimic the structure of leather as a single- or multi-layer material, thus promoting a circular economy and zero waste of persimmons. The shift to a more circular economy can bring benefits such as reduced pressure on the environment, improved conservation of raw material supplies, increased competitiveness, stimulated innovation, promoted economic growth, and job creation. The project is a sustainable solution that addresses the need for the development of plant-based, eco-friendly leather as an alternative to synthetic and natural leather, minimizing the environmental and health impacts of petroleum-based raw materials.

[0054] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one skilled in the art of the present invention. Methods and materials similar or equivalent to those described herein can be used in the practice of the present invention. Throughout the detailed description and claims, the word "comprise" and variations thereof are not intended to be limiting and therefore not to exclude other technical features, additives, components, or steps. The term "comprise" further includes the term "consists of."

[0055] The following figures are illustrative of the present invention and should not be construed as limiting the present invention in any way. [Brief explanation of the drawings]

[0056] [Figure 1] Figure 1 shows the production of leather-type materials of vegetable origin. A. Gelatinization of cornstarch in water. B. Plasticization of gelatinized cornstarch. C. Thermoplastic gel. [Figure 2] 1A-1C show layers of composition in a mold with a leather texture: A. Top view B. Side view. [Figure 3] FIG. 1 illustrates a leather-type material of vegetable origin obtained by the process of the present invention.

[0057] Examples of the present invention The present invention will be described in the following examples, as well as in the figures and schematic diagrams. The substituents and integers used in the following schemes are as defined in the embodiments of the present invention unless otherwise specified. This section is provided to aid in the understanding of the present invention, but should not be construed as limiting the invention described in the claims in any way.

[0058] Example 1: Production of vegan leather made from persimmon and starch-derived polymers and plant-based polyols. Fragments of brilliant red persimmons from the Ribera del Xuque, Valencia (Spain) region were collected. The fruits were blended and frozen at -20°C until use. The persimmons were thawed to obtain a persimmon mass. The fruit mass used for leather production may be persimmons obtained by mechanically crushing fruit pieces into a puree form, residue from Soxhlet extraction of persimmon fruit, fruit pulp, or a combination thereof. In this example, persimmon puree was used. The persimmon mass was weighed and stored. 10 g of cornstarch was dissolved in 62.5 g of distilled water at 80°C with continuous stirring and stirred at 70-80°C until a gel formed. The solution was maintained at this temperature for 30 minutes until a nearly translucent gel formed. Figure 1A shows the cornstarch granules dissolved in water. 5 g of glycerol was added to the solution with stirring, and the mixture was heated to 70-80°C for approximately 10 minutes. At this point, the gelation process began. The stirring speed was increased (e.g., 2500 rpm) to avoid the formation of lumps, and the mixture was maintained at 80 °C for 10 minutes with continuous stirring using a hand blender. Figure 1B shows the gelatinized cornstarch after the addition of glycerol. Continued stirring with heating resulted in the starch molecules being fully gelled. This moment was identified because the mixture acquired a homogeneous, translucent appearance (Figure 1C). All starch granules had completely transformed into a translucent gel phase, which was termed "glycerol-simulated plasticized starch (GTPS)" or plasticized starch. After uniform GTPS was produced, the product was weighed. A 22 g portion of persimmon mass was added to 77.5 g of plasticized starch. At this stage, 0.5 g of the dye charcoal was also added to obtain the final black color. The addition of the dye was solely intended to impart the desired color to the final material; it is not an essential component of the mixture. The mixture was continuously mixed until it was completely homogenized, resulting in a composite material. Complete homogenization is important to ensure uniform particle size. Once the mixture was completely homogenized, it was added to a mold with a pattern resembling animal leather. Figure 2 shows the mold and composite material with a leather texture.

[0059] Example 2: Production of coated vegan leather from persimmon and starch-derived polymers. A layer of 100% cotton fiber was placed on top of the composite material obtained in Example 1. After assembly, the sandwich was placed in a forced air drying oven. The sandwich was then left at room temperature for another 24 hours. Finally, the material was removed from the mold. Figure 3 shows the leather-type material obtained after the process. Its appearance was identical to that of animal-derived leather. To obtain a waterproof, protective material, a coating layer was added to the material obtained in Example 1. Natural beeswax was mixed with olive oil in a 1:1 ratio (w / w) while heating to 40°C until the beeswax was completely dissolved. The solution was cooled and evenly applied to the leather-type material. After heating in an oven at 70°C for 2 minutes, excess coating was removed, and the material was dried again at 70°C for 2 minutes. An additional layer of the mixture was added, and the process was repeated.

[0060] Example 3: Production of four-layer vegan leather from persimmon and starch-derived polymers. To expand the application of the material of the present invention, a four-layer leather-like material was developed. A water-based polyurethane was added to the embossed paper and cured at 100°C for 2 minutes. The water-based polyurethane was over 47% biobased. After this layer dried, a layer of the material obtained in Example 1 was added on top of the polyurethane layer (top layer), and both layers were cured at 70°C for 1 hour and 30 minutes. After drying, an adhesive layer of water-based polyurethane adhesive was added on top of the persimmon layer (middle layer), and finally, a 100% cotton woven fabric layer was added. The four-layer structure was cured at 100°C for 2 minutes. After the material was completely dry, the embossed paper was removed. This material was designed to mimic the structure of leather as a multilayer material. The woven fabric support (100% cotton) performs the mechanical function, while the persimmon-containing middle layer is responsible for the feel and softness of the final material, as well as the flexibility and mechanical resistance of the polyurethane top layer. Table 1 shows the distribution of the material's layers and the percentage of biobased elements in the final material. [Table 1]

[0061] From this table it can be concluded that the total biobased content in the material is greater than 85%.

[0062] Example 4: Characterization of layered vegan leather The mechanical properties of the material of Example 3 were compared with commercially available materials of animal origin. Two tests were selected to determine the abrasion resistance and color fastness to cycles of reciprocating friction. The determination of abrasion resistance was carried out according to standard method EN13520:2001 / A1:2004. The method was carried out in a Martindale abrasion tester at a test pressure of 12 Pa. Table 2 shows the results of the assay. The results show that the material of the present invention passed the abrasion resistance test in the same way as other commercially available leathers, making it suitable for the manufacture of clothing and goods. [Table 2] (*) Commercially available

[0063] Color fastness was measured according to ISO 11640:2018. This method examines how leather behaves in a test in which a standardized piece of wool is moved back and forth a specified number of times. Color change during the test is assessed using a standardized gray scale. When performing this test, any other visible changes or damage to the leather surface must also be reported. The value must be a maximum of 5, the highest grade A, with any lower value indicating a color change. Trademarks and manufacturers require this test to have a value of at least 4 at the end of the cycle. Table 3 shows the results of the assay. In this case, the material of the present invention behaved similarly to animal leather, exhibiting a grade of 4 and slight coating removal after 6,400 cycles, both of which are acceptable in the textile industry. [Table 3] (*) Commercially available

[0064] When leather is intended for use on either the foot contact side or non-contact side of an article, the standard is run at 100 and 50 cycles, with a maximum required grade of 3 or higher on the gray scale to pass. The results above show that the grades for each material after several cycles represent average results. The material of the present invention achieved a score of 5 in all tests, even after 150 cycles instead of the 100 cycles required by other materials, or after 50 cycles instead of the 10-50 cycles required by other materials. These results demonstrate that the material of the present invention performs exceptionally well, even outperforming other commercially available leathers. These results demonstrate that the performance of the material of the present invention meets two of the most important tests required by manufacturers and designers of natural leather.

[0065] Example 5: Production of vegan leather from persimmon and PU formed with plant-derived isocyanates and polyols. Persimmon puree was obtained as described in Example 1. 48 g of this persimmon mass was mixed with 46 g of naturally occurring PU, and the mixture was stirred. While stirring, 5 g of soybean oil and 1 g of natural pigment were added to the mixture, and stirring was maintained for 5 to 10 minutes. To produce a multilayer vegan leather material, a mixture of aqueous PU and additives was added to embossed paper, which would provide the texture for the final top layer, to obtain a layer less than 200 micrometers thick. This layer was then dried by passing it through a ventilated oven at a temperature above 100°C for several minutes to obtain the top layer. The previously obtained persimmon mass-based mixture was then added to this dried top layer. This application was carried out in a continuous, slow stream, and could have a variable thickness depending on the thickness of the final sample. This was then dried by passing it through a ventilated oven at a temperature above 100°C. A bio-based PU adhesive was prepared and spread on the dried persimmon layer along with an organic support (cotton cloth in this case). The two layers were pressed together and placed in an oven to dry for several minutes. Finally, the product is cured in an oven for 3 to 5 minutes at a temperature of 135-140°C. In the resulting material, layer (a) represents 11% by weight, layer (b) 51% by weight, layer (c) 8% by weight and layer (d) 30% by weight, based on the total weight of the layered material.

[0066] Example 6: Testing the physical and mechanical properties of layered materials of vegan leather derived from persimmon and PU. The purpose of this study was to compare the properties of the vegan material of the present invention with existing products on the market, as shown in the table below. [Table 4]

[0067] [Table 5]

[0068] [Table 6]

[0069] [Table 7]

[0070] In terms of thickness, it can be seen that there are products that are thicker and thinner than the product of the present invention, which means that the vegan leather of the present invention is on par with similar products, with 36% of competing products being thicker and 64% being thinner.

[0071] The layer mass fraction is a very important property in terms of the physical parameters of the product and depends on the textile substrate used and the interlayer of persimmon deposited.

[0072] The tensile strength test evaluates the resistance of a fabric when a certain force is applied until it breaks. As can be seen from the results, the breaking strength values ​​of the vegan leather of the present invention are also in line with many of the results of competitive products. 45% of the competitive products exceed this value, and 55% fall below it. The elongation resistance of the material of the present invention can only be compared to the resistance achieved by fruit leather. As can be seen in this example, although the value of fruit leather is even higher, the value of 26.74% achieved by the vegan leather of the present invention already exceeds the acceptable value for the clothing market, which is the market that most needs this property.

[0073] Tear resistance is a highly important property in the fashion clothing, upholstery, contract leather, and footwear markets, where the values ​​achieved by the vegan leather of the present invention are far higher than other products, surpassed only by those of natural skin.

[0074] The water vapor permeability test determines the breathability of the product, a relevant property in the clothing market. The breathability value is 85% lower compared to natural skin, but 45% higher and 55% lower compared to other products, so it can be said that the vegan leather of the present invention is in line with the results of other commercially available products.

[0075] The results obtained in the bending strength tests are very favorable for the vegan leather of the present invention, being higher than the values ​​of other products and at the same level as natural animal skin.

[0076] This color fastness to artificial light test determines a product's resistance to fading due to continued exposure to artificial light, a property that has a significant impact in the automotive and contract leather markets.

[0077] The vegan leather of the present invention has been compared only with fruit leather and it can be seen that the values ​​of the vegan leather of the present invention are clearly between 125 and 150% in terms of color fastness. According to the UNE-EN 14465:2004 / A1 standard, within the range of performance levels A to E, the vegan leather of the present invention is at level A, which is highly favorable for the upholstery, automotive and contract leather markets.

[0078] Abrasion resistance is more important in the footwear or upholstery market. The value of this property was measured only for the vegan leather of the present invention, and according to the UNE-EN 14465:2004 / A1 standard, within the range of performance levels A to E, this product achieved level B, which is very favorable for the upholstery market.

Claims

1. A composition for vegan leather comprising a polymer derived from persimmon (Diospyros kaki) and a plant-derived polyol.

2. 2. The composition according to claim 1, wherein said persimmon represents from 20 to 60% by weight relative to the total weight of said composition, and said polymer represents from 40 to 80% by weight relative to the total weight of said composition.

3. 3. The composition according to claim 2, wherein said persimmon represents from 30 to 40% by weight relative to the total weight of the composition, and said polymer represents from 60 to 70% by weight relative to the total weight of the composition.

4. 2. The composition of claim 1, wherein the polymer is a plasticized starch derived from starch and glycerol of vegetable origin, preferably the starch is corn starch.

5. The composition of claim 1 , wherein the polymer is a polyurethane derived from a vegetable polyol.

6. 2. The composition according to claim 1, further comprising 0.1 to 1% by weight of a dye of vegetable origin relative to the total weight of the composition.

7. 10. The composition of claim 1, further comprising 1 to 10% by weight, based on the total weight of the composition, of a vegetable oil selected from sesame oil, canola oil, sunflower oil, soybean oil, peanut oil, olive oil, corn oil, bean oil, grape seed oil, jojoba oil, palm oil, cottonseed oil, almond oil, safflower oil, walnut oil, avocado oil, rice bran oil, and linseed oil.

8. 2. The composition of claim 1, further comprising from 0.5 to 2% by weight of an additive selected from thickeners, crosslinkers, and stabilizers, relative to the total weight of the composition.

9. A vegan leather material comprising the composition of claim 1.

10. The following layers: a) a top layer comprising a water-based polyurethane; b) a second layer comprising the composition of claim 1; c) a third layer comprising a water-based polyurethane having adhesive properties; and d) an optional fourth layer which is a textile layer; 10. The material of claim 9, which is a layered material comprising:

11. 11. The material according to claim 10, wherein said layer (a) represents 10 to 20% by weight relative to the total weight of the material, and / or said layer (b) represents 20 to 70% by weight relative to the total weight of the material, and / or said layer (c) represents 2 to 10% by weight relative to the total weight of the material, and / or said layer (d) represents 30 to 50% by weight relative to the total weight of the material.

12. 12. The material according to claim 10 or 11, wherein said layer (a) is coated with a composition comprising a wax and a vegetable oil.

13. 13. The material of claim 12, wherein the wax and the vegetable oil are in a 1:1 ratio.

14. 13. The material of claim 12, wherein the wax is selected from beeswax, montan wax, candelilla wax, and carnauba wax.

15. 13. The material of claim 12, wherein the vegetable oil is selected from sesame oil, canola oil, sunflower oil, soybean oil, peanut oil, olive oil, corn oil, bean oil, grape seed oil, jojoba oil, palm oil, cottonseed oil, almond oil, safflower oil, walnut oil, avocado oil, rice bran oil, and flaxseed oil.

16. 12. The material according to claim 11, wherein the thickness of layer (a) is from 0.05 to 0.30 mm, and / or the thickness of layer (b) is from 0.20 to 1.50 mm, and / or the thickness of layer (c) is from 0.05 to 0.20 mm, and / or the thickness of layer (d) is from 0.20 to 0.50 mm.

17. The following steps: a) depositing a first layer of water-based polyurethane onto a substrate; b) drying the polyurethane of step a) at a temperature of 100-120°C for 1-10 minutes; c) adding a layer of the persimmon-containing composition of claim 1 to the dried polyurethane of step b); d) drying the two layers at a temperature of 70-150°C for 5 minutes to 2 hours; e) adding a third layer of water-based polyurethane having adhesive properties onto the layer containing dried persimmons from step d), and optionally adding a textile layer onto the adhesive layer of step e); f) drying at a temperature of 100-150°C for 1-5 minutes; A process for obtaining the layered material of claim 10.

18. 18. The process of claim 17, wherein the support of step a) presents a pattern for imprinting a pattern onto the top layer (a).

19. 11. An article comprising the vegan leather material of claim 10.

20. 20. The article of claim 19, selected from a textile product, a footwear product, a leather product, a bookbinding, a picture frame, a bag, furniture, a watch band, a cover, a bracelet, a handle, a basket, a key chain, or a mask.

21. Use of persimmon (Diospyros kaki) to produce vegan leather.

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