Bio-based materials and methods for preparing them

Abstract

A bio-based material and a method for preparing the same are provided. The present disclosure relates to a method for the preparation of a bio-based material that can resemble animal leather from a mixture comprising (i) plant proteins, (ii) one or more vegetable tanning agents, and (iii) one or more plasticizers.

Description

【Technical Field】 【0001】 The present invention relates to a method for preparing a bio-based material from plant proteins that can resemble animal leather. 【Background Art】 【0002】 The leather industry has been frequently criticized for its environmental impacts. The large consumption of water, the input of numerous chemicals, and the disposal of potential chemical and organic wastes into the air and water during the tanning process contribute to the negative image of this industry. Many consumers are concerned about these environmental problems associated with turning a blind eye to animal leather. To address these concerns for these ecosystems and to meet new requirements, new materials similar to animal leather have emerged and continue to emerge. The main alternatives proposed are either fully synthetic petroleum-based materials (e.g., polyvinyl chloride) or are made from natural or synthetic fiber substrates coated with plastic materials such as polyurethane. There are other more confidential and expensive alternatives, such as pineapple leather made from pineapple leaves, eucalyptus leather made from eucalyptus leaves, or mushroom leather. Very commonly, polyurethane is mixed with these natural elements. Also, it has been proposed to prepare alternatives to animal leather from plant proteins. Thus, Japanese Patent Laid-Open No. 04-153378 proposes a method for preparing an alternative material that includes a step of extruding plant proteins (soybean proteins) followed by a chromium or plant-based tanning step of the resulting material. 【0003】 However, some of these alternatives do not appear to be entirely satisfactory from an ecological standpoint. Polyurethane-based materials are derived from petrochemicals and are difficult to integrate into ecologically responsible preparation methods. In addition, the material lifecycle is not always considered as a whole. Recycling some of these alternatives, particularly those involving polyurethane and related fibers, can be difficult. Finally, these alternatives do not yield materials that possess thermoplastic properties. Therefore, there is still a need for bio-based, recyclable materials that can be used for a wide variety of applications in various technological fields. Advantageously, the proposed material can serve as a preferred alternative to animal leather. Furthermore, the method for preparing this material is rapid, economical, and environmentally friendly. Bio-based materials have been proposed, for example, by U.S. Patent No. 6,902,783, European Patent Application Publication No. 0976,790, and Sun et al., Food Hydrocolloids, vol. 21, pp. 1005-1013. These materials are obtained by crosslinking biopolymers or plant proteins using aldehyde or polyaldehyde type crosslinking agents. The method does not use plant tanning agents. Subsequently, the chemical bonds formed are covalent bonds, and it is not possible to obtain recyclable, thermoplastic-like materials. [Overview of the project] 【0004】 The present invention relates to a method for preparing a semi-finished product from plant protein, (a)(i) plant proteins, (ii) One or more plant-based tanning agents, (iii) One or more plasticizers The steps include: fluidizing and kneading a mixture containing the following: (b) The step of compressing a fluidized and kneaded mixture in order to produce a semi-finished product Methods including This also relates to semi-finished products and their use in the preparation of articles (commercial products) that can be obtained by such methods. The present invention also relates to a method for preparing an article from a semi-finished product as described herein, comprising the step of forming the semi-finished product under pressure by extrusion calendering, extrusion expansion, extrusion spinning, injection molding, 3D printing, or molding. The present invention also relates to an article obtained by such a method. Other aspects of the present invention are as described below and in the claims. [Brief explanation of the drawing] 【0005】 [Figure 1] This figure shows photographs of samples T1 to T4 obtained by extrusion. [Modes for carrying out the invention] 【0006】 The inventors have developed a method for preparing semi-finished products that resemble animal leather in a specific form (sheet, film, plate), or for preparing semi-finished products that enable the preparation of materials from plant proteins that can resemble animal leather. Therefore, the present invention relates to a method for preparing a semi-finished product from plant protein, (a)(i) plant proteins, (ii) One or more plant-based tanning agents, (iii) One or more plasticizers The steps include: fluidizing and kneading a mixture containing the following: (b) The step of compressing a fluidized and kneaded mixture in order to produce a semi-finished product This includes methods. The present invention also relates to semi-finished products that can be obtained by the method of the present invention. In this explanation, the term "semi-finished product" refers to a product that serves as the basis for the preparation of a wide variety of goods. 【0007】 The term "semi-finished products" includes, but is not limited to, sheets, films, plates, wires, technical profiles, rods, tubes, solid shapes, and pellets. Examples of articles that can be prepared from the semi-finished products of the present invention include, but are not limited to, packaging, molded articles intended for contact with food (cups, food containers, cutlery, etc.), molded articles for household, textile or decorative use (pots, boxes, protective shells, buttons, tokens, handles, armrests, soles, etc.), textile articles and accessories, leather goods and accessories, sporting goods, films or nets for agricultural or horticultural use, finishing films for flexible materials, and foams. The semi-finished products can also be used to prepare aqueous solutions and suspensions for surface coatings. In this explanation, the term "technical profile" refers to a material that has been given a specific shape. The method of the present invention and the semi-finished products that can be obtained by this method are as follows. 【0008】 Components of a mixture for preparing a semi-finished product The semi-finished product of the present invention is obtained by fluidizing, kneading, and compressing a mixture comprising i) plant protein, (ii) one or more plasticizers, and (iii) one or more plant tanning agents. The mixture may further contain any organic or inorganic additives / components (e.g., fillers, dyes, pigments, viscosity modifiers, pH adjusters, preservatives, hydrophobic substances, surfactants, ionic modifiers, UV stabilizers). A mixture of plant proteins, one or more plant tanning agents, and one or more plasticizers results in the preparation of thermoplastic materials. Therefore, such properties offer a wide variety of shaping possibilities, allowing the material to be adapted to its intended use. The direct addition of one or more plant tanning agents to a mixture containing plant proteins and plasticizers unexpectedly makes it possible to successfully prepare materials that resemble animal leather and exhibit increased flexibility and good water resistance. Furthermore, such materials have the advantage of being recyclable. 【0009】 protein In the context of the present invention, useful proteins are plant proteins, such as proteins derived from plants or algae. The mixture typically contains 15-70% by mass, preferably 20-60% by mass, of plant protein, based on the total mass of the mixture. Preferably, the mixture does not contain animal protein (mammals, fish, birds, reptiles, and amphibians). Plant proteins useful in the context of the present invention are preferably cereal proteins (e.g., wheat, buckwheat, barley, rye, maize, oats, spelt wheat, quinoa, amaranth, chia, millet, rice), legume proteins (e.g., beans, peas, broad beans, lupine, lentils, carob, licorice, alfalfa, clover, fenugreek), and oilseed proteins (e.g., soybeans, rapeseed, flaxseed, cannabis, sunflower, castor, yam). The proteins are selected from the group consisting of oak acorns, peanuts, sesame seeds, walnuts, almonds, cotton, pumpkin seeds, grape seeds, olives, coconuts, hazelnuts, macroalgae proteins (brown algae, green algae, and charophytes, red algae), microalgae proteins (diatoms, green algae, golden algae, and cyanobacteria) (e.g., Arthrospira platensis (spirulina), Chlorella vulgaris (chlorella)) and mixtures thereof. Wheat proteins, particularly wheat gluten, broad bean, and chlorella proteins are especially useful in the context of the present invention. 【0010】 The mixture typically contains 20-85% by mass, preferably 15-70% by mass, or 20-60% by mass, or 35-75% by mass, of plant protein, based on the total mass of the mixture. The plant protein is generally added to the mixture in the form of a plant protein formulation, for example, oilseed meal (e.g., rapeseed, flaxseed, cannabis, sunflower meal), or concentrates or isolates (e.g., pea concentrate, broad bean concentrate), or protein concentrate powder. If the plant protein is wheat gluten, various qualities of gluten can be used. Plant proteins or plant protein formulations are typically used in solid form, such as powder. 【0011】 plasticizer The plasticizer used in this invention acts as a plasticizer and / or modifier. The plasticizer reduces the viscosity of the mixture and thus facilitates its processing. The plasticizer also increases the flexibility of the material obtained by this method, particularly the flexibility of sheets or films that can be formed after being formed or semi-formed. Useful plasticizers in the context of the present invention are preferably water, crude glycerol, purified glycerol, glycerol derivatives (e.g., glyceryl mono, di- and tri-acetates, diglycerol, polyglycerin, glycerol esters, polyglycerol esters, glycerol carbonate), alcohols, polyols (e.g., propanediol, butanediol, pentanediol, xylitol, erythritol, arabitol, isosorbide, sorbitol, mannitol, maltitol, polyethylene glycol, phenol), saccharides and oligosaccharides, lignans, preferably saturated or lignans having 2 to 10 carbon atoms. The plasticizer is selected from the group consisting of unsaturated carboxylic acids and their salts (e.g., acetic acid, propionic acid, lactic acid, isobutyric acid, pentanoic acid, hexanoic acid, gluconic acid, sorbic acid, caprylic acid, benzoic acid, gallic acid, hydroxybenzoic acid, salicylic acid, caffeic acid, cinnamic acid, hydroxycinnamic acid, ascorbic acid, succinic acid, tartaric acid, capric acid, or their constituent isomers or salts), coumarin, sulfonic acid, amino acids (e.g., proline, leucine, isoleucine, lysine, cysteine), urea, ionic liquids (e.g., ammonium salts), eutectic solvents (e.g., choline / glycerol), and mixtures thereof. In some preferred embodiments, the plasticizer is selected from glycerol, urea, water, propanediol, potassium sorbate, and mixtures thereof, preferably from glycerol, urea, water, and mixtures thereof. In some embodiments, the plasticizer is a mixture containing glycerol and a plasticizer other than glycerol. In some embodiments, the plasticizer is a mixture containing water and a plasticizer other than water. Therefore, in these embodiments, the plasticizer may be an aqueous solution of a plasticizer other than water. 【0012】 The mixture (which will be fluidized and kneaded) typically contains 15 to 85% by mass, preferably 20 to 70% by mass or 20 to 60% by mass or 35 to 55% by mass of a plasticizer, based on the total mass of the mixture. Since the plasticizer can be used alone or in a mixture, it is understood that the mixture typically contains 15 to 85% by mass or 20 to 70% by mass or 20 to 60% by mass or 35 to 50% by mass of a plasticizer or a mixture of plasticizers, based on the total mass of the mixture. The plasticizer can be used in solid form or liquid form. In some embodiments, the mixture contains no added water (any water present is provided only by the components of the mixture). 【0013】 Tanning agent Plant tanning agents (or vegetable tannins) useful in the context of the present invention include polyphenolic tanning agents and mixtures thereof. Polyphenolic tanning agents typically contain 2 to 10 phenolic units that can be bonded to sugars or terpenes. The plant tanning agent can be natural (e.g., plant extract) or can be obtained by chemical synthesis. Preferably, the plant tanning agent is a natural agent. The mixture typically contains 0.01 to 20% by mass, preferably 2 to 15% by mass or 2 to 8% by mass, of one or more tanning agents selected from polyphenolic tanning agents, based on the total mass of the mixture. In some embodiments, an inorganic tannin for reversible tanning, such as potassium alum, can be added to the plant tanning agent. In some embodiments, the mixture does not contain organic tanning agents selected from aldehydes (e.g., polyaldehydes, dialdehydes, glutaraldehyde, formaldehyde, quinones, phospholipids, polyphosphates) and mixtures thereof. Such agents cause irreversible cross-linking of the material. 【0014】 In some embodiments, the mixture does not contain inorganic (metallic or mineral) tannins selected from chromium salts, aluminum salts, zirconyl salts, iron and / or titanium salts, sulfur, or mixtures thereof. Such agents cause irreversible crosslinking of the material. Polyphenolic tanning agents can be selected from synthetic agents (e.g., naphthalene polymers, phenolic polymers, bisphenolic polymers, and combinations thereof). Plant tannins (plant tanning agents) are polyphenols that have the ability to bind to and precipitate proteins. Based on their structural characteristics, tannins can be classified into four main groups of flavonoids, including gallotannins, ellagitannins, tannin complexes, and condensed tannins. Gallotannins are tannins formed by galloyl units or their derivatives, metadepside units, linked to various polyol units, flavanol units, or triterpenoid units. Ellagitanins are tannins formed by at least two galloyl units linked together by C-C bonds and do not contain glycosidic bonds with catechin units. Tannin complexes are those in which gallotannin or ellagitannin units are linked to catechin units by glycosidic bonds. Condensed tannins are proanthocyanidols formed by a bond between C-4 of one catechin unit and C-8 or C-6 of another catechin unit. They typically contain 2 to 8 catechin units and are present in concentrations of 300 to 100,000 g / mol. -1 They have molecular weights in the range of [range]. Catechin monomers are part of the broader flavonoid family, along with isoflavonoids, flavones, flavonols, flavanonols, flavanones, aurones, chalcones, dihydrochalcones, anthocyanidols, flavandiols, and flavan-3-ols (catechins), anthocyanidins, and flavan compounds. Plant tannins can be extracted from the xylem, bark, leaves, roots, galls, pits, peels, and seeds of a wide variety of plant species. 【0015】 In the context of the present invention, useful plant tannins are preferably condensed tannins (flavonoids) or hydrolyzable tannins. In the context of the present invention, some of the plant tannins particularly useful include those derived from plant species selected from the group consisting of chestnut, mimosa, pine, spruce, willow, birch, mangrove, quebracho, oak, cashew, heather, canaigre, lacquer tree, gambier, myrobalan, tara, acacia, hawthorn, pecan, grape, sorghum, cranberry, cocoa, coffee, buckthorn, spicebush, and mixtures thereof. The mixture typically contains 0.01 to 20% by mass, preferably 2 to 15% by mass or 2 to 8% by mass, of one or more plant tannins, based on the total mass of the mixture. Plant tannins are typically used in solid form, such as powder. 【0016】 Any additives The mixture may further contain functional additives. Adding fillers provides structural reinforcement to the formed material (reinforcing fillers), thus improving its resistance and reducing its deformation. Furthermore, if the fillers are hygroscopic, they can help regulate the moisture content of the material. Therefore, the mixture may contain 0.05 to 20% by mass, preferably 0.1 to 15% by mass, of the total mass of the mixture as a reinforcing filler. Preferably, the filler is a cellulose derivative (e.g., cellulose fibers, microcrystalline cellulose), an organic filler (e.g., cross-linked starch, wool, lignin, lignosulfonates), an inorganic filler (e.g., clay, glass fibers, rock fibers, calcium carbonate, zinc oxide, silica), a synthetic filler (e.g., bio-based polymers, petroleum-derived polymers, recycled thermoplastics, and thermosetting resins), or a mixture thereof. Biomass derivatives, such as wood, flax, hemp, wheat, apples, and other agricultural food by-products, can be sources of cellulose and lignin derivatives. 【0017】 The mixture may further contain a coloring agent or pigment. Therefore, the mixture may contain 0.01 to 30% by mass, preferably 0.05 to 10% by mass, of a coloring agent or pigment based on the total mass of the mixture. Preferably, the coloring agent is a natural coloring agent (e.g., indigo, flavones, flavonols, flavonoids, polyphenols). Preferably, the coloring pigment is titanium dioxide. The mixture may also contain odorants (e.g., fragrances, aromatic plant extracts, essential oils). The mixture may further contain an agent (e.g., ferulic acid) for controlling browning reactions, such as the Maillard reaction. The mixture may also contain viscosity modifiers. Viscosity modifiers can be used to promote textureization of the material. Therefore, the mixture may contain 0.01 to 30% by mass, preferably 0.05 to 10% by mass, of the total mass of the mixture, of the viscosity modifier. Preferably, the viscosity modifier is selected from powders (e.g., corn flour, grain flour, protein flour, oilseed flour), natural and modified polysaccharides (e.g., starch, hemicellulose, alginates, carrageenan, acacia gum, guar gum, mucilage, chitin and its derivatives, hydroxylated, methylated, carboxymethylated and / or ethylated cellulose), and mixtures thereof. Various starches, such as corn starch, wheat starch, potato starch and mixtures thereof, can be used. The starch may be natural or can be modified by, for example, gelatinization or chemical treatment (e.g., oxidized, acetylated, carboxymethylated, hydroxyethylated, crosslinked starch). 【0018】 The mixture may further contain a preservative, which may be present in an amount of 0.01 to 3% by mass, preferably 0.1 to 1% by mass, based on the total mass of the mixture. Preferably, the preservative is selected from organic substances (e.g., propionic acid, sorbic acid and its calcium and potassium salts, benzoic acid, fumaric acid, dimethyl dicarbonate) and inorganic substances (e.g., sulfites, sulfur dioxide, nitrates, nitrites, sodium chloride), and mixtures thereof. The mixture may further contain agents that improve the processability and flexibility of the material. Examples of such agents include terpene derivatives, such as terpenes derived from orange or wood (e.g., pine resin). 【0019】 The mixture may also contain hydrophobic substances. Hydrophobic substances can improve the appearance and feel of the material, reduce its moisture permeability and hygroscopicity, and reduce the material's sensitivity to water. Therefore, the mixture may contain 0.01 to 5% by mass, preferably 0.05 to 2% by mass, of hydrophobic substances based on the total mass of the mixture. Preferably, the hydrophobic substances are selected from the group consisting of oils (e.g., grape seed oil, rapeseed oil, sunflower oil, linseed oil, hemp oil, castor oil, cottonseed oil, olive oil, avocado oil, tall oil, peanut oil, which contain fatty acids that can be modified), fats, natural and modified lecithins, waxes (e.g., beeswax, carnauba wax), and mixtures thereof. The mixture may further contain a pH adjuster. The pH adjuster may allow for adjustment of the solubility of plant proteins and other compounds used. Therefore, the mixture may contain 0.01 to 5% by mass, preferably 0.05 to 2% by mass, of the pH adjuster based on the total mass of the mixture. Preferably, the pH adjuster is selected from acetic acid, citric acid, tartaric acid, formic acid, lactic acid, slaked lime, soda ash, hydrochloric acid, and mixtures thereof. The mixture may also contain salts to alter the ionic properties of the plant proteins. 【0020】 Method for preparing semi-finished products Fluidization of a mixture comprising (i) a protein, preferably a plant protein, (ii) one or more plasticizers, (iii) one or more tanning agents, preferably plant tannins, and (iv) optionally the aforementioned additives is typically achieved by heating the mixture to a temperature in the range of 60 to 250°C, preferably 90 to 180°C, or even 140 to 160°C. This temperature is typically chosen to fluidize the mixture without decomposing its components. The processing temperature depends on the formulation of the mixture, typically the content of the plasticizers. Therefore, the heating temperature is typically lower than the thermal decomposition temperature of the components of the mixture. In some embodiments, the temperature is about 150°C. Mechanical kneading is used to homogenize the mixture. Kneading is typically carried out at the fluidization temperature. The mixture is typically processed in an extruder equipped with an extrusion head called a "die." Thus, the mixture is fluidized and kneaded in the extruder, and then compressed in the die to form a semi-finished product. 【0021】 These semi-finished products are made from materials that possess thermoplastic properties. Furthermore, these materials are biodegradable. Therefore, in other words, the present invention relates to a method for preparing a semi-finished product from a protein, preferably a plant protein, comprising the steps of extruding and compressing a mixture comprising (i) a protein, preferably a plant protein, (ii) one or more tanning agents, preferably plant tannins, (iii) one or more plasticizers, and (iv) optionally an additive. The compression is carried out using a die. The selection of a die at the extruder outlet is understood to define the properties and geometric structure of the semi-finished product. Dies can be used to obtain sheets, films, plates, wires, rods, tubes, solid shapes, and technical profiles. The extruder may be a conventional screw extruder commonly used for extruding thermoplastic materials. The extruder may be a single or multiple screw extruder rotating in a barrel. Preferably, the extruder is a twin-screw extruder, typically a co-rotating twin-screw extruder. The L / D ratio of the extruder (L = screw length, D = screw diameter) is typically in the range of 10 to 100, preferably 20 to 60. The rotational speed of one or more screws is typically in the range of 10 to 1500 rpm, preferably 200 to 1000 rpm. 【0022】 The extruder includes at least one conveying zone and at least one mixing zone. The extruder may include alternating conveying zones and mixing zones. The conveying zone allows for the mixing, gradual compression, and heating of solids and liquids. The mixing zone allows for more vigorous mixing of the components of the mixture, particularly by increasing the residence time. The extruder may also include a degassing zone, either in the open air or using suction. The temperature within each zone of the extruder can vary. Typically, an extruder includes at least one transport zone having a temperature up to 250°C and at least one kneading zone having a temperature up to 200°C. The extruder may also include a heating zone to gradually raise the temperature of the transport zone to the temperature of the kneading zone. At the inlet to the die, the temperature of the mixture can vary typically between 90 and 180°C and cool to a temperature typically in the range of 70 to 150°C within the die. The screw profile can be selected according to the constraints that a person skilled in the art would like to apply to the mixture. The residence time of the mixture in the extruder is typically in the range of 20 seconds to 15 minutes, preferably 2 to 6 minutes. The components of the mixture are introduced into the extruder through a feed hopper, either in liquid or solid form. These components can be introduced through the main feed port and optionally secondary ports, using a metering device for solids or a pump for liquids. For example, proteins, preferably plant proteins, are introduced typically in solid form, plasticizers in liquid form, and tanning agents in solid form. 【0023】 The components are typically introduced into the extruder at a temperature of 20-90°C. In other embodiments, the components of the mixture may be mixed using a co-kneader. Next, the resulting semi-finished products are cooled to their final shape in ambient air, in a liquid bath such as water or fat, or on a cooled cylinder. Typically, the cooling device is placed at the die outlet. Thus, the method of the present invention may include a step for cooling the prepared semi-finished products. The method may also include a step of drying the prepared semi-finished product. When the mixture is compressed into profiles, pipes, or rods, these profiles, pipes, or rods can then be cut into pellets. Cutting may be performed before or after cooling. Therefore, the method of the present invention may include a granulation step. The granulation operation may be carried out under conventional conditions well known to those skilled in the art. Next, the resulting pellets can be formed under pressure according to techniques well known in the field of plastic processing, for example, by extrusion calendering, extrusion expansion, extrusion spinning, injection molding, 3D printing, or molding. Accordingly, the present invention also relates to a method for preparing an article from pellets, comprising the step of forming the article under pressure by extrusion calendering, extrusion expansion, extrusion spinning, injection molding, 3D printing, or molding. 【0024】 Therefore, pellets can be used to prepare a wide variety of commercial products, such as sheets, films, packaging, molded articles intended for contact with food (cups, food containers, cutlery, etc.), molded articles for household, textile or decorative use (jars, boxes, shells, souvenirs, handles, etc.), textiles, leather goods, sporting goods, films or nets for agricultural or horticultural use, finishing films for flexible materials, and foams. If the mixture is compressed into a sheet (e.g., using a flat die) or pellets are used to form a sheet, these sheets may be further processed. For example, the sheet can be calendered. Calendering can flatten the surface of the sheet, reduce its thickness, or print texture, such as leather grain, onto the surface of the sheet. Printing leather grain can give the resulting material a look or feel more like animal leather. In particular, the sheet can be used as a leather substitute for the manufacture of objects that are typically made from animal hides or that incorporate animal hide parts. The formed material can also be used as a fabric coating substrate, or can be used in multilayer configurations with other materials. 【0025】 Accordingly, the semi-finished products described herein can be used to prepare a wide variety of articles, such as sheets, films, packaging, objects intended for contact with food (cups, food containers, cutlery, etc.), molded articles for household, textile or decorative use (pots, boxes, protective shells, buttons, souvenirs, handles, etc.), textile articles and accessories, leather goods and accessories, sporting goods, films or nets for agricultural or horticultural use, finishing films for flexible materials, and foams. Accordingly, the present invention also relates to a method for preparing an article from a semi-finished product as described herein, comprising the step of shaping the semi-finished product. Shaping the semi-finished product is typically carried out under pressure by extrusion calendering, extrusion expansion, extrusion spinning, injection molding, 3D printing, or molding. Therefore, the present invention also relates to articles prepared from semi-finished products described herein. These articles may be injection-molded articles. Advantageously, the method of the present invention avoids the tanning step typically performed in the preparation of leather substitutes. These tanning steps consume large amounts of water. Therefore, from an economic standpoint, the method of the present invention is highly competitive as it allows for savings on this high water consumption and the costs associated with treating the water used for tanning. 【0026】 Furthermore, by directly introducing a tanning agent, preferably a vegetable tannin, into the mixture intended to be compressed, the material preparation can be made highly flexible. In particular, the material obtained by the method of the present invention has higher flexibility than the material obtained by a method that includes a separate tanning step. The resulting material is flexible, not brittle, and strong. Furthermore, the material obtained by the method of the present invention has good abrasion resistance. This material is also waterproof and has good water resistance. The following examples are given for illustrative purposes only. These examples should not be construed as limiting the invention. [Examples] 【0027】 Commercially available reference materials Gluten: Manito (Eurogerm) wheat protein (reference number FZG309461), Vital wheat gluten (Roquette Freres), White Chlorella: White Chlorella Powder (Reference No. 910287) (Greentech SA) Broad bean protein: Fava bean protein 60 SMP (Univar), Glycerol: Lucemill Ltd., Vegetable Glycerin (VG) EP / BP Pharmaceutical Grade, Catechu, myrobalan, buckthorn, berry, white grape tannin, chestnut tree and Occitan chestnut tree extract, ferrous sulfate: Green'ing SARL, Gambier: Pure Catecu Extract (SCRD), Kaolin: PoleStar 200R (Imerys) Corn bran: Sofabran 184-80, corn fiber (Limagrain Ingredients). 【0028】 1. Preparation of samples according to the present invention The sample is prepared in a Thermo Scientific® brand name Eurolab16 extruder, 16 mm in diameter and 640 mm in length, equipped with a flat film die having an adjustable center-to-center distance with a thickness of 100 μm to 1 mm. The extruder has two intake zones, at least one transport zone using compression, at least one mixing zone, and a die zone. The rotational speed of the two axes is 500 rpm, and the temperature range in different zones is 40-160°C. Proteins, tannins, and solid-form additives were introduced into the first uptake zone. Plasticizers and liquid additives were introduced into the second intake zone. The screw profiles are as follows: a 22mm mixing screw and a 128mm direct pitch screw. Samples EI1 to EI4 were prepared by extrusion of the following mixture (percentages are given as mass relative to the total mass of the mixture). 【0029】 [Table 1] 【0030】 The previously presented mixture produced a tacky material that can be compressed and / or molded. The resulting samples are flexible and mechanically strong, just like leather. Furthermore, these samples possess a fixed chemical structure that protects them from mold. The sample was found to have good water resistance. Therefore, after being submerged in 65°C water overnight, only slight swelling was observed, and the appearance of the sample remained almost unchanged. The sample was found to have a structure that was slightly softer than before immersion, and to have good mechanical resistance, particularly tear resistance that was very close to that of the sample before immersion. The following table shows the characteristics of the EI4 sample. The tests were conducted according to the method listed in the third column of the table. 【0031】 [Table 2] 【0032】 The measured properties of sample EI4 indicate that it meets several criteria of the leather specifications (water resistance, i.e., impermeability to water droplets, abrasion resistance, and grain strength against balls). When the fracture test results are good, it can be seen that sample EI4 has a lower modulus of elasticity and a higher elongation at fracture than leather. These differences can be explained by the absence of reinforcing fillers. 2. Preparation of comparative samples - without tanning agent As described above, the sample is prepared in a Eurolab 16 extruder equipped with a flat film die. Samples EC1 to EC4 were prepared by extrusion of the following mixtures (percentages are given as mass relative to the total mass of the mixture). 【0033】 [Table 3] The comparative samples EC1 to EC4 were found to be highly sensitive to water. Consequently, the appearance of the samples changed after being immersed in water at 65°C overnight. The samples swelled and had a very soft structure. Sample EC3 had lost its structure. Furthermore, after being submerged in water at 65°C overnight, their mechanical resistance decreased (they became extremely brittle). 【0034】 3. Preparation of comparative samples - Tanning following extrusion As shown in the table above, sample EC4 was extruded using high-concentration water without the use of a tanning agent, allowing for the imparting of a remarkable texture visible to the naked eye. Next, the sample EC4 prepared as described above was treated under conditions that generally mimicked those described in Japanese Patent Publication No. 04-153378. Japanese Patent Publication No. 04-153378 provides a method for preparing a material, comprising a step of extruding plant protein (soy protein), followed by a step of plant or chrome tanning of the resulting material. 【0035】 Therefore, the sample EC4 was then immersed in aqueous baths of various tanning materials (catecu, myrobalan, chestnut, potassium alum extract, and water only) at gradually increasing concentrations, and then rinsed with water. Next, the sample was left to stand to dry slowly. Immersion tests in water demonstrated that the samples obtained after drying exhibited good water resistance (less degradation compared to sample EC4). Therefore, this tanning process effectively fixed the structure of the plant proteins. Furthermore, tanning increased the sample's resistance to mold (fungal growth was slower compared to sample EC4). However, the obtained samples were found to be extremely brittle (fragile). Their properties were nowhere near comparable to those of leather. 【0036】 4. Mechanical properties Samples EI5-EI16 and P1-P2 were prepared in a Thermo Scientific® brand Eurolab16 extruder with a diameter of 16 mm and a length of 640 mm, equipped with a 2 mm diameter snap ring die. The extruder has two intake zones, at least one transport zone using compression, at least one mixing zone, and a die zone. The rotational speed of the two shafts is 500 rpm, and the temperature range in different zones is 40-160°C. The calculated mechanical specific energy is 50-210 J / g. Proteins, tannins, and solid-form additives were introduced into the first uptake zone. Plasticizers and liquid additives were introduced into the second intake zone. The screw profiles are as follows: a 22mm mixing screw and a 128mm direct pitch screw. Samples EI5-EI16 and P1-P2 were prepared by extrusion of the following mixture (percentages are given as mass relative to the total mass of the mixture). Samples EI5-EI16 and P1-P2 were prepared by extrusion of the following mixture (percentages are given as mass relative to the total mass of the mixture). 【0037】 [Table 4] 【0038】 [Table 5] 【0039】 After extrusion, rods of samples EI5-EI9 and P1-P2 were compressed as 2mm thick plates at 130°C and 60 bar for 15 minutes. Type 1BA test specimens were cut, conditioned at 40°C and 50% relative humidity, and subjected to unidirectional mechanical tensile tests at a speed of 10 mm / min according to EN ISO 527-2:2012. To quantitatively compare the flexibility of samples EI5 to EI9, they were subjected to dynamic mechanical spectroscopy (DMA) analysis at a rate of 2°C / min from -100°C to 150°C at a frequency of 1 Hz while embedded in a single layer. The glass transition temperature was determined by the peak of the loss coefficient. Furthermore, the samples were subjected to mechanical tensile testing on a Shimadzu bench, with an average of five test pieces tested at a rate of 10 mm / min. 【0040】 The table below shows the characteristics of EI5-EI9 and P1-P2 samples. [Table 6] 【0041】 Samples EI5 to EI9 exhibited fracture strains that were compatible with use in leather products, despite having considerably low fracture strains due to the absence of reinforcing fillers in these samples. When gradually increasing amounts of tanning agent are added, the mechanical properties of the sample do not change dramatically with respect to tensile strength at room temperature, but the glass transition temperature and elastic modulus, measured by DMA, clearly progress up to 7.9% tannin. This demonstrates the ability of vegetable tanning agents to impart flexibility to the material without weakening it. Furthermore, samples P1-P2, based on white chlorella and broad bean concentrate, exhibited lower mechanical strength than the gluten-based blend, but were found to be thermoplastic and flexible. Samples EI10 to EI15 were also subjected to mechanical tensile testing as described above. In addition, these samples were compared to specifications used in the leather goods industry. 【0042】 Abrasion resistance was quantified by the Veslic test in accordance with ISO standard 11640:2018. The samples and rubbed felt were compared to grayscale in accordance with ISO 105 A02:1993 and ISO 105 A03:2019. The samples were also subjected to bending strength tests in accordance with ISO 5402-1:2017, and surface extension and tensile strength tests in accordance with the ball method (ISO 3379:2015). The table below shows the characteristics of EI10 to EI15 samples. 【0043】 [Table 7] By changing the plant source of the vegetable tanning agent, it is possible to alter the fracture strain from 43% to over 70%, effectively doubling the fracture strain. Abrasion resistance is variable. Nevertheless, it is still possible to meet the standard specifications for leather products. It is possible to achieve thousands of bending cycles without tearing the sample. All samples exhibit high resistance to ball penetration. 【0044】 Samples EI10 to EI15 exhibit a wide range of flexibility, which can be achieved by changing the plant source of the incorporated plant tannins. 5. Adding texture Samples T1 to T4 were prepared in a Thermo Scientific® brand Eurolab16 extruder, 16 mm in diameter and 640 mm in length, equipped with a flat film die having an adjustable gap thickness of 100 μm to 1 mm. The extruder has two intake zones, at least one transport zone using compression, at least one mixing zone, and a die zone. The twin-screw rotation speed is 300 rpm, and the temperature in different zones is 40-200°C. The final extrusion zone and flat film die temperature is 40-100°C. Proteins, tannins, and solid-form additives were introduced into the first uptake zone. Plasticizers and liquid additives were introduced into the second intake zone. The screw profiles are as follows: a 22mm mixing screw and a 128mm direct pitch screw. Samples T1 to T4 were prepared by extrusion of the following mixtures (percentages are expressed as mass relative to the total mass of the mixture). 【0045】 [Table 8] 【0046】 Observe the appearance of the extruded material. If the resulting sheet does not have a homogeneous texture, it is not suitable for use. The results are shown in Figure 1. Formulation T1 containing 4.5% additional water (additive water) is observed to exhibit significant structural defects, namely bubbles, pores, and sheet asymmetry. Therefore, it is preferable that no additional water is added to the mixture. 【0047】 For other formulations, a uniform fiber texture is obtained, and the sheet is soft. The sheet can be calendered between rolls with adjustable gaps, and heating may or may not be required. When only one side of the roll is heated, it is possible to obtain a fibrous side on one side and a flat side on the other (sample T4). This double surface is similar to leather that has a textured side and a fleshy side.

Claims

[Claim 1] A method for preparing a semi-finished product from plant protein, (a) (i) Plant proteins, (ii) one or more plant tanning agents, and (iii) Containing one or more plasticizers, (iv) A mixture which may contain a reinforcing filler, If the reinforcing filler is present, the mixture is fluidized and kneaded, and the mixture contains 0.05 to 20% by mass of the reinforcing filler relative to the total mass of the mixture. (b) The step of compressing the fluidized and kneaded mixture in order to produce a semi-finished product. Methods that include... [Claim 2] The method according to claim 1, wherein the tanning agent is selected from polyphenolic tanning agents. [Claim 3] The method according to claim 1, wherein the protein is a plant protein selected from the group consisting of cereal proteins, leguminous proteins, oilseed proteins, macroalgae proteins, microalgae proteins, and mixtures thereof. [Claim 4] The method according to claim 1, wherein the protein is wheat gluten. [Claim 5] The method according to claim 1, wherein the plasticizer is selected from the group consisting of water, crude glycerol, purified glycerol, glycerol derivatives, alcohols, polyols, saccharides and oligosaccharides, lignans, saturated or unsaturated carboxylic acids and their salts, coumarins, sulfonic acids, amino acids, urea, ionic liquids, eutectic solvents, and mixtures thereof. [Claim 6] The method according to claim 1, wherein the plasticizer is selected from the group consisting of glycerol, urea, water, and mixtures thereof. [Claim 7] The method according to claim 1, wherein the mixture further comprises organic or inorganic additives selected from fillers, dyes, pigments, viscosity modifiers, pH adjusters, preservatives, hydrophobic substances, surfactants, ionic modifiers, UV stabilizers, and mixtures thereof. [Claim 8] The method according to claim 1, wherein fluidization is achieved by heating the mixture to a temperature in the range of 60 to 250°C. [Claim 9] The method according to claim 1, wherein the fluidization, kneading, and compression of the mixture are performed in an extruder equipped with an extrusion head. [Claim 10] The method according to claim 1, wherein the semi-finished product is a sheet, film, plate, wire, technical profile, tube, rod, or pellet. [Claim 11] A step of cooling the prepared semi-finished product, A step of drying the prepared semi-finished product, If the semi-finished product is a technical profile, tube, or rod, the step involves granulating the prepared semi-finished product. The method according to claim 10, further comprising one or more of the above. [Claim 12] A semi-finished product that can be obtained by the method described in any one of claims 1 to 11. [Claim 13] The semi-finished product according to claim 12, wherein the semi-finished product is a sheet, film, plate, technical profile, tube, rod, or pellet. [Claim 14] Use of the semi-finished product according to claim 12 or 13 for preparing an article. [Claim 15] An article prepared from the semi-finished product according to claim 12 or 13. [Claim 16] The article according to claim 15, wherein the article is an article that is injection molded. [Claim 17] A method for preparing an article from a semi-finished product according to claim 12 or 13, comprising the step of forming the semi-finished product under pressure by extrusion calendering, extrusion expansion, extrusion spinning, injection, 3D printing or molding.

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