Coating Method for Mycelium-Based Composite Materials Using a Water-Dispersed Emulsion

Abstract

The present invention relates to a method for coating the surface of a mycelium-based composite material and a mycelium-based composite material coated by said coating method. The coating method of the present invention involves applying a coating to a molded mycelium body immediately after demolding, thereby not inhibiting the growth of the mycelium, and allowing the wax to naturally melt and rearrange during the drying process to form a uniform protective film. Accordingly, swelling or damage to the appearance caused by moisture absorption by the mycelium can be prevented, and moisture resistance and durability can be improved.

Description

Technology Field

[0001] The present invention relates to a method for coating the surface of a mycelium-based composite material using a water-dispersible emulsion capable of forming a uniform coating layer on the surface of the mycelium-based composite material even at low temperatures, and to a mycelium-based composite material coated by the said coating method. Background Technology

[0003] Mycelium-based composite materials are attracting attention as eco-friendly alternatives to plastics due to their biodegradability, lightweight properties, and porosity. However, mycelium is highly susceptible to moisture, leading to issues such as reduced structural strength, swelling, discoloration, and cracking upon moisture absorption. To address these problems, technologies for forming coating layers using waxes or resins have been developed; however, most of these methods involve melting waxes at high temperatures exceeding approximately 80°C or using organic solvents, making them difficult to apply to mycelium, which is sensitive to heat and solvents. Furthermore, water-dispersible coating agents with low wax content exhibit insufficient moisture-proof performance, while high content leads to reduced emulsion stability, resulting in limitations such as phase separation or uneven coating. In particular, if the drying temperature exceeds the melting point of the wax, the coating layer flows down, causing an uneven surface and exposing the mycelium, which in turn reduces the moisture-proof effect.

[0004] Therefore, there is a growing need to develop a water-dispersible wax-based coating technology that can form a uniform coating layer by stably melting at low temperatures without inhibiting mycelial growth. In particular, there is a demand for a new technology that simultaneously satisfies moisture resistance, appearance, quality, and eco-friendliness by precisely controlling the drying process and an emulsion-type wax composition that can be applied to mycelial composite materials immediately after demolding under low-temperature conditions. The problem to be solved

[0006] Mycelium-based composite materials are attracting attention as eco-friendly alternatives to plastics due to their biodegradability, lightweight properties, and porosity. However, mycelium is highly susceptible to moisture, leading to issues such as reduced structural strength, swelling, discoloration, and cracking upon moisture absorption. To address these problems, technologies for forming coating layers using waxes or resins have been developed; however, most of these methods involve melting waxes at high temperatures exceeding approximately 80°C or using organic solvents, making them difficult to apply to mycelium, which is sensitive to heat and solvents. Furthermore, water-dispersible coating agents with low wax content exhibit insufficient moisture-proof performance, while high content leads to reduced emulsion stability, resulting in limitations such as phase separation or uneven coating. In particular, if the drying temperature exceeds the melting point of the wax, the coating layer flows down, causing an uneven surface and exposing the mycelium, which in turn reduces the moisture-proof effect.

[0007] Therefore, there is a growing need to develop a water-dispersible wax-based coating technology that can form a uniform coating layer by stably melting at low temperatures without inhibiting mycelial growth. In particular, there is a demand for a new technology that simultaneously satisfies moisture resistance, appearance, quality, and eco-friendliness by precisely controlling the drying process and an emulsion-type wax composition that can be applied to mycelial composite materials immediately after demolding under low-temperature conditions. means of solving the problem

[0009] To solve the above-mentioned technical problem, the present invention provides a method for coating the surface of a mycelium-based composite material, comprising: (S1) a step of preparing a water-dispersible emulsion comprising a wax and a surfactant including a main coating agent and an auxiliary coating agent; (S2) a step of applying the water-dispersible emulsion to the surface of the molded body of the mycelium composite material immediately after demolding; (S3) a step of culturing the mycelium composite material coated with the water-dispersible emulsion at 20 to 40°C; and (S4) a step of treating the mycelium composite material coated with the water-dispersible emulsion at a temperature of 50 to 75°C for 0.5 to 2.5 hours to form a moisture-proof coating layer.

[0010] The main coating agent and auxiliary coating agent used in the above coating method may comprise one or more selected from the group consisting of carnauba wax, candelilla wax, soy wax, coconut wax, and beeswax.

[0011] In addition, the surfactant comprises (i) one or more nonionic surfactants selected from the group consisting of Tween 20, Tween 80, Span 20, Span 80, Lecithin, Sorbitan monostearate, Sorbitan tristearate, Polyoxyethylene stearate, Polyoxyethylene cetyl ether, PEG-40 Hydrogenated Castor Oil, Glyceryl stearate, Decaglyceryl monooleate, or Steareth-10·20; (ii) one or more anionic surfactants selected from the group consisting of sodium stearoyl lactylate, sodium lauryl sulfate, sodium lauryl ether sulfate, sodium stearate, potassium stearate, sodium oleate, sodium myristoyl glutamate, sodium lauroyl sarcosinate, sodium lauryl lactylate, or disodium laureth sulfosuccinate, or (iii) a combination thereof.

[0012] In one embodiment, step (S1) may include (S1-1) dissolving a main coating agent and an auxiliary coating agent at 60 to 90°C for 1 to 30 minutes; (S1-2) adding a surfactant and preparing a mixture; (S1-3) adding distilled water preheated to 70 to 90°C to the mixture and stirring; and (S1-4) cooling at 20 to 30°C and stirring to stabilize the prepared emulsion.

[0013] In one embodiment, the coating layer may be characterized by having a coating thickness of 10 mm or less.

[0014] In one embodiment, based on the total weight of the water-dispersible emulsion, the wax may be included in an amount of 40 to 70 weight%, the surfactant in an amount of 1 to 10 weight%, and distilled water in an amount of 40 to 75 weight%.

[0015] In one embodiment, the step (S4) may involve treating the mycelial composite material coated with the water-dispersible emulsion at a temperature of 50 to 60°C for 1 to 2 hours to induce melting and rearrangement of the wax.

[0017] In addition, the present invention provides a mycelium-based composite material coated by the above method.

[0018] In one embodiment, the coated mycelium-based composite material may have a mycelium layer present on top of the coated layer. Effects of the invention

[0020] The coating method of the present invention involves applying a coating to a molded mycelium body immediately after demolding, thereby not inhibiting the growth of the mycelium. During the drying process, the wax naturally melts and rearranges to form a uniform protective film. Consequently, swelling or external damage caused by moisture absorption by the mycelium can be prevented, and moisture resistance and durability can be improved. Furthermore, as an eco-friendly process that does not use high temperatures or organic solvents, it offers high production efficiency and quality stability. Additionally, it can simultaneously ensure long-term storage stability and external protection while maintaining the ecological characteristics of the mycelium. Therefore, the necessity of the present invention is emerging as a new eco-friendly surface treatment technology that enhances the industrial utility of mycelium composite materials. Specific details for implementing the invention

[0022] Hereinafter, the specific configuration and effects of the present invention will be described with reference to the attached drawings, etc.

[0023] In this specification, singular expressions include plural expressions unless the context clearly indicates otherwise.

[0024] In this specification, the terms “Comprise” and / or “Comprising” specify the presence of the mentioned features, steps, numbers, actions, parts, elements, and / or groups thereof, and do not exclude the presence or addition of one or more other features, steps, numbers, actions, parts, elements, and / or groups thereof.

[0025] Where various embodiments are described in this specification, each embodiment may be combined unless specifically stated otherwise. In this case, the effects of the present invention may be defined as including effects derived from each embodiment and effects resulting from the organic combination of each embodiment. For example, even if embodiments 1 and 2 are described independently in this specification, unless the context clearly indicates otherwise, embodiments 1 and 2 may be organically combined with each other, and the effects of the present invention may include effects resulting from the combination of embodiments 1 and 2.

[0026] In this specification, the range of numerical values ​​indicated by the term 'to' represents a range of numerical values ​​that includes the values ​​listed before and after the term as the lower limit and upper limit, respectively. For example, if the specification states a to b or c to d, it may be understood that a to b (a to b), a to d (a to d), c to d (c to d), or c to b (c to b).

[0027] In the present specification, if multiple numerical values ​​are disclosed for the upper and lower limits of any numerical range, the numerical range disclosed in the present specification may be understood as a range of any numerical values ​​in which any one of the multiple lower limit values ​​and any one of the multiple upper limit values ​​are respectively the lower limit value and the upper limit value. For example, if a or greater, or b or greater; and c or less, or d or less is described, it may be understood as a or greater and c or less, a or greater and d or less, b or greater and c or less, or b or greater and d or less.

[0028] In this specification, "composition" may mean a mixture of materials including said composition, a reaction product formed from the materials of said composition, or a decomposition product.

[0029] As used in this specification, “water-dispersed emulsion” refers to the same concept as “water-dispersed wax coating composition” and may be used interchangeably depending on the context. That is, the water-dispersed emulsion in the present invention includes a composition used to form a coating layer in which a wax component exists in a form finely dispersed in the aqueous phase, and such a composition may also be expressed as a “water-dispersed wax coating composition.”

[0030] In the present invention, the term "mushroom strain (spawn)" refers to the original mushroom mycelium capable of growing mushrooms. Specifically, since the mushroom spawn is intended for the production of mushroom fruiting bodies and the fruiting bodies are consumed rather than the mycelium, a grain medium or sawdust medium spawn is prepared using a solid or liquid material (e.g., rice straw, waste cotton, sawdust, chickpeas, chemically mixed water, etc.) as the main medium, and the completed spawn is used as an inoculum. The spawn is then inoculated into a medium made using a large amount of another solid material as the main material to proliferate the mycelium, and the resulting fruiting bodies are produced. This spawn can then be used as a means for the movement, storage, and proliferation of the mycelium for consumption.

[0031] The term “mycelium” refers to an aggregate of intertwined hyphae produced through the germination of spores, from which the above-ground parts of the mushroom develop. The mycelium, which is the vegetative stage of the mushroom, contains various useful substances and, in particular, has the advantage of being able to be stably cultured and produced in a container for a short period, unlike the fruiting body.

[0032] In the present invention, the term "culture" refers to growing the strain of the present invention under appropriately controlled environmental conditions. The culture process of the present invention may be carried out according to suitable media and culture conditions known in the art. Such a culture process can be easily adjusted and used by those skilled in the art depending on the selected strain. Specifically, the culture may be batch, continuous, and / or fed-batch, but is not limited thereto.

[0033] In the present invention, the term "medium" refers to a substance mixed with nutrients as the main component required to culture the strain of the present invention, and supplies nutrients and growth factors, including water, which is indispensable for survival and growth. Specifically, the medium and other culture conditions used for culturing the strain of the present invention may be any medium used for culturing conventional strains without special limitations; however, the strain of the present invention may be cultured under aerobic conditions while controlling the temperature, pH, etc., in a conventional medium containing a suitable carbon source, nitrogen source, phosphorus, inorganic compounds, amino acids, and / or vitamins.

[0035] The present invention provides a method for coating the surface of a mycelium-based composite material, comprising: (S1) a step of preparing a water-dispersible emulsion comprising a wax and a surfactant including a main coating agent and an auxiliary coating agent; (S2) a step of applying the water-dispersible emulsion to the surface of a molded body of a mycelium composite material immediately after demolding; (S3) a step of culturing the mycelium composite material coated with the water-dispersible emulsion at 20 to 40°C; and (S4) a step of treating the mycelium composite material coated with the water-dispersible emulsion at a temperature of 50 to 75°C for 0.5 to 2.5 hours to form a moisture-proof coating layer.

[0036] In this specification, “water dispersibility” refers to the property of a non-polar or semi-solid substance being finely dispersed via water without the use of an organic solvent. That is, a water-dispersible substance maintains a stable dispersed or emulsified state without phase separation when directly mixed with water, and includes a state in which aggregation or precipitation is not significant even after long-term storage. In the present invention, it refers to the characteristic in which waxes are stably dispersed in an aqueous phase, contributing to the formation of a uniform coating layer.

[0037] In this specification, the term “emulsion” refers to an emulsified dispersion formed by dispersing one of two immiscible liquid phases (e.g., wax and water) in the form of fine droplets within the other liquid phase. An emulsion is generally composed of an oil phase and a water phase, and is a substance in which stability is maintained by reducing the interfacial tension between the two phases through a surfactant. The emulsion in the present invention refers to a water-in-oil type emulsion in which the wax component mainly exists in the oil phase and water exists in the continuous phase, and is a functional emulsion that has excellent viscosity stability even at low temperatures and forms a uniform moisture-proof coating layer through the melting and rearrangement of the wax upon drying.

[0038] The main coating agent and auxiliary coating agent in the above emulsion may use vegetable and animal waxes, but for example, the vegetable and animal waxes may include one or more selected from the group consisting of carnauba wax, candelilla wax, soy wax, coconut wax, and beeswax. In addition, the main coating agent and auxiliary coating agent may be characterized by not including synthetic and petroleum-based waxes, for example, paraffin, microstalin wax, and montan wax. If synthetic and petroleum-based waxes are included, the stability of the water-dispersible emulsion is reduced, which may cause phase separation or aggregation during long-term storage. Furthermore, it is difficult to ensure consistent quality in terms of the uniformity and biodegradability of the coating layer, so it does not meet the purpose of an eco-friendly coating process.

[0039] In addition, the surfactant comprises (i) one or more nonionic surfactants selected from the group consisting of Tween 20, Tween 80, Span 20, Span 80, Lecithin, Sorbitan monostearate, Sorbitan tristearate, Polyoxyethylene stearate, Polyoxyethylene cetyl ether, PEG-40 Hydrogenated Castor Oil, Glyceryl stearate, Decaglyceryl monooleate, or Steareth-10·20; (ii) one or more anionic surfactants selected from the group consisting of sodium stearoyl lactylate, sodium lauryl sulfate, sodium lauryl ether sulfate, sodium stearate, potassium stearate, sodium oleate, sodium myristoyl glutamate, sodium lauroyl sarcosinate, sodium lauryl lactylate, or disodium laureth sulfosuccinate, or (iii) a combination thereof.

[0040] In addition, the above emulsion may be characterized by not including cationic surfactants and amphoteric surfactants. If the above emulsion includes cationic surfactants, it is unsuitable as an eco-friendly coating composition because cationic surfactants may cause skin irritation and environmental side effects, and if it includes amphoteric surfactants, it does not meet the scope of the purpose of the present invention due to issues such as reduced stability due to pH changes and relatively high manufacturing costs.

[0041] The above step (S1) may include: (S1-1) a step of dissolving a main coating agent and an auxiliary coating agent at, for example, 60 to 90°C, 70 to 90°C, or 75 to 90°C for, for example, 1 to 30 minutes, 5 to 30 minutes, 10 to 30 minutes, or 10 to 50 minutes; (S1-2) a step of adding a surfactant and preparing a mixture; (S1-3) a step of adding distilled water preheated to, for example, 70 to 90°C or 80 to 90°C to the mixture and stirring; and (S1-4) a step of cooling at 20 to 30°C and stirring to stabilize the prepared emulsion.

[0042] In one embodiment, the coating layer may be characterized by having a coating thickness of 10 mm or less. If the coating thickness exceeds 10 mm, heat is not uniformly transferred to the interior of the wax layer during the drying process, resulting in uneven melting and rearrangement of the coating layer and reduced surface uniformity. On the other hand, within the range of 10 mm or less, the wax layer melts and rearranges uniformly, making it possible to form a uniform moisture barrier without inhibiting the growth of mycelia.

[0043] The above water-dispersible emulsion may contain wax in an amount of, for example, 40 to 70% by weight, 40 to 65% by weight, or 40 to 60% by weight based on the total weight of the water-dispersible emulsion. If the wax content in the water-dispersible emulsion is less than 40% by weight, water repellency and moisture resistance are insufficient when forming a coating layer, making it difficult to form a uniform film, and the water resistance of the surface after drying tends to decrease. On the other hand, if it exceeds 70% by weight, the oil phase ratio becomes excessively high, resulting in poor emulsification, and droplet aggregation or phase separation of the free-phase wax may occur, which may reduce the stability of the composition.

[0044] In addition, the above water-dispersible emulsion may contain a surfactant in an amount of, for example, 1 to 10 weight%, 1 to 8 weight%, 1 to 6 weight%, or 1 to 5 weight% based on the total weight of the water-dispersible emulsion. If the surfactant content is less than 1 weight%, the dispersibility of wax particles decreases, which lowers the stability of the emulsion, and precipitation or aggregation may occur during long-term storage. Conversely, if it exceeds 10 weight%, an excessive amount of surfactant remains, which reduces the mechanical strength and water resistance of the coating layer, and increases the tackiness of the surface upon drying, which may degrade the appearance quality.

[0045] In addition, the above water-dispersible emulsion may contain distilled water in an amount of, for example, 40 to 75% by weight, 45 to 75% by weight, 45 to 70% by weight, or 50 to 70% by weight based on the total weight of the water-dispersible emulsion. If the content of distilled water is less than 40% by weight, the viscosity is excessively high, making it difficult to apply uniformly, and if it exceeds 75% by weight, the dilution is high, which reduces the continuity of the coating layer and may not sufficiently exhibit a moisture-proof effect.

[0046] The coating method used in the above (S2) step may utilize contact coating methods such as brushes or rollers, and, if necessary, non-contact coating methods such as spraying, dipping, or airbrushing may be used. The selection of such coating methods can be adjusted according to the shape, size, and required coating thickness of the mycelial surface, and it is desirable to disperse the coating at a uniform thickness over the entire surface so that a uniform film is formed after application. Since the coating step of the present invention is based on the characteristics of a low-viscosity water-dispersible emulsion, it has the advantage of being able to form a uniform and continuous coating layer without inhibiting the growth of the mycelium without a separate heating process.

[0047] The above step (S2) may include (S2-1) a step of manufacturing a mycelial composite material comprising a culture containing mushroom mycelium, a porous filler, a nutrient source, a plasticizer, and a curing agent, and demolding a molded body; and (S2-1) a step of applying the water-dispersible emulsion to the surface immediately after demolding the molded body of the mycelial composite material.

[0048] If a wax-based emulsion coating solution is applied after the mycelium has been fully cultured, the mycelium layer may be damaged or detached due to moisture and adhesive components in the coating solution, resulting in an uneven surface structure. On the other hand, if a water-dispersible emulsion is applied immediately after demolding the molded body, a uniform coating layer can be formed without hindering the growth of the mycelium, and the mycelium can naturally grow outward from the coating layer during the subsequent culture process to form an integrated structure. Therefore, the method of the present invention includes the step of applying the water-dispersible emulsion to the surface immediately after demolding the molded body of the mycelium composite material, thereby ensuring adhesion of the coating layer without damaging the mycelium layer, and inducing rearrangement of the coating layer during the culture and drying process to form a surface protective film with excellent moisture resistance and water resistance.

[0049] The above mycelium-based composite material may include a culture medium comprising mushroom mycelium obtained by inoculating a mushroom strain into a sawdust medium and culturing it, a porous filler, a nutrient source, a plasticizer, and a curing agent.

[0050] The above step (S4) may induce the melting and rearrangement of the wax by treating the mycelial composite material coated with the water-dispersible emulsion at a temperature of, for example, 50 to 75°C or 50 to 60°C for, for example, 0.5 to 2.5 hours, 1 to 2 hours, or 1.5 to 2 hours. Specifically, the step (S4) may include a step of melting the coated water-dispersible emulsion at a temperature of 50 to 60°C for 1 to 2 hours; and a step of drying the melted water-dispersible emulsion at a temperature of 40 to 60°C, wherein the melting step and the drying step may proceed simultaneously.

[0051] The melting process performed in step (S4) above is a step distinct from the drying process for simple moisture removal, in which wax particles are partially melted and rearranged by heat to form a continuous coating film. On the other hand, the drying process is primarily intended to remove water through the evaporation of moisture and is a process maintained in a discontinuous state where bonding between particles does not occur. In the drying process, only the evaporation of moisture proceeds, whereas in the melting process, a protective film with uniform waterproof and moisture-proof functions can be formed through the melting and re-solidification processes of the wax. Therefore, in order to secure the formation of a uniform film and the effect of protecting the appearance, which cannot be achieved by simple drying alone, it is desirable that step (S4) above include a process in which the rearrangement of the wax through melting and drying processes proceeds simultaneously. Accordingly, the melting process is a separate functional step with a different purpose and function from the drying process, and the present invention is characterized by a low-temperature melting-based coating technology with this as its core.

[0053] In addition, the present invention provides a mycelium-based composite material coated by the above method.

[0054] The above-described coated mycelium-based composite material may have a mycelium layer present on top of the coated layer. Accordingly, the composite material has a structure formed by the growth of mycelium on the outer side of the coating layer, which is possible because the coating process is performed immediately after demolding the molded body, rather than after the growth of the mycelium is completed. Following this process sequence, the coating layer does not hinder the growth of the mycelium, and the mycelium naturally diffuses and forms on the outer side of the coating layer, thereby maintaining a state of biological activity. As a result, the composite material of the present invention forms a three-layer integrated structure consisting of an inner raw material layer, an intermediate coating layer, and an outer mycelium layer, and can simultaneously secure excellent water resistance and moisture resistance without damaging the mycelium layer. Therefore, the coating method of the present invention is a process in which the growth of the mycelium and the formation of the coating layer are in harmony, and is characterized by the ability to simultaneously achieve the maintenance of the functional activity of the mycelium and the surface protection function.

[0055] The above mycelium-based composite material may include a culture comprising mushroom mycelium obtained by inoculating a mushroom strain into a sawdust medium and culturing it, a porous filler, a nutrient source, a plasticizer, and a curing agent. The above mushroom mycelium comprises a mushroom strain, and the strain may include a species in which the mycelium is easily killed by drying, for example, Pleurotus ostreatus, Ganoderma lucidum, Vanderbylia fraxinea, Trametes versicolor, Lentinula edodes, Schizophyllum commune, Phanerochaete chrysosporium It may be one or more selected from a group consisting of

[0056] The porous filler is a component that supports the growth of mycelia and seeds by improving air permeability, moisture retention, and drainage through the formation of pores, and may include, for example, perlite, vermiculite, fine diatomite, or a combination thereof. The porous filler may be included in an amount of, for example, 10 to 30 weight%, 10 to 25 weight%, or 10 to 20 weight% based on the total weight of the composite material precursor.

[0057] The above nutrient source is a source of carbon and nitrogen necessary for the growth of mycelium and the germination and early growth of seeds, and may include, for example, wheat bran, corn flour, rice bran, yeast extract, or a combination thereof. The above nutrient source may be included in an amount of, for example, 5 to 20 weight%, 5 to 15 weight%, or 5 to 10 weight% based on the total weight of the entire composite material precursor.

[0058] The above plasticizer is a component that secures flexibility within the composite material, stabilizes moisture content, and induces a uniform distribution of mycelium, and may include, for example, glycerol, sorbitol, polyethylene glycol (PEG-400, etc.), or a combination thereof. The above plasticizer may be included in an amount of, for example, 1 to 20 weight%, 1 to 15 weight%, or 1 to 10 weight% based on the total weight of the entire composite material precursor.

[0059] The above curing agent is a component that strengthens bonding strength within the composite material, stabilizes shape, and imparts physical strength to the mycelial mat structure, and may include, for example, sodium alginate, calcium carbonate, gelatin, agar, or a combination thereof. The above curing agent may be included in an amount of, for example, 5 to 20 weight%, 5 to 15 weight%, or 5 to 10 weight% based on the total weight of the entire composite material precursor. In one embodiment, as an example of a curing agent, 3 to 5% sodium alginate and 1 to 5% calcium carbonate were used in combination to induce curing and immobilization of the mycelial network.

[0061] The features of each of the various embodiments of the present invention may be combined or combined with one another, either partially or wholly, and as will be fully understood by those skilled in the art, various technical interlocking and operation are possible, and each embodiment may be implemented independently of one another or together in an interlocking relationship.

[0062] In interpreting the components, they are interpreted to include a margin of error even in the absence of a separate explicit description.

[0063] The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining embodiments of the present invention are exemplary, and therefore the present invention is not limited to the depicted details. Furthermore, in describing the present invention, if it is determined that a detailed description of related known technology may unnecessarily obscure the essence of the present invention, such detailed description is omitted. Where terms such as "includes," "has," or "is made up" are used in this specification, other parts may be added unless "only" is used. When a component is expressed in the singular, it includes cases where it is included in the plural unless specifically stated otherwise.

[0065] The following examples and experimental examples will be explained in more detail. However, these examples and experimental examples are intended to illustrate one or more specific embodiments, and the scope of the present invention is not limited to these examples and experimental examples.

[0067] Example 1. Preparation of a wax-based water-dispersible coating composition

[0068] [Example 1-1]

[0069] A coating composition suitable for use in mycelial complexes was prepared. A water-dispersible wax coating composition was prepared using the composition of Table 1 below.

[0070] Ingredient name Content (w / w%) Soy wax 30.70 coconut wax 13.16 Tween 80 3.51 distilled water 52.63

[0071] Soy wax and coconut wax were mixed according to the composition of Table 1 above and completely dissolved at 75°C for about 20 minutes. Subsequently, Tween 80, a nonionic surfactant, was added to the dissolved wax mixture and mixed uniformly. Next, distilled water preheated to about 75°C was slowly added to the oil phase mixture while high-speed stirring to emulsify. The emulsification process was maintained for about 10 minutes, resulting in the formation of a stable, milky white cream-type emulsion. During the cooling process to room temperature, low-speed stirring was maintained to stabilize the viscosity of the emulsion, and it was confirmed that the emulsion remained in a stable state without phase separation even after cooling was complete.

[0073] [Examples 1-2]

[0074] Another water-dispersible wax coating composition was prepared using the composition of Table 2 below.

[0075] Ingredient name Content (w / w%) Carnauba wax 20.00 Beeswax 10.00 Tween 80 2.00 Span 80 1.00 distilled water 67.00

[0076] Carnauba wax and beeswax were completely dissolved at 85 to 90°C for 20 minutes according to the composition of Table 2 above. Subsequently, Tween 80 and Span 80 were sequentially added to the dissolved wax mixture and mixed uniformly. Separately, distilled water preheated to 80°C was prepared and slowly added to the oil phase mixture while performing high-speed stirring. After emulsification was completed, the viscosity was stabilized by maintaining low-speed stirring while cooling at room temperature, and after cooling was complete, a coating agent in the form of a stable cream-type emulsion was obtained.

[0078] Example 2. Preparation and Coating Treatment of Mycelium-Based Plant Growth Composite Material

[0079] A mycelial composite material for plant growth was prepared, and a surface coating was performed using the water-dispersible wax coating composition prepared in Example 1.

[0080] First, mushroom strains ( Pleurotus ostreatus A raw material was prepared in which mycelium (53 wt%) could grow uniformly by inoculating it and culturing it for about 10 days under conditions of 25°C and 95% relative humidity. Perlite (about 14 wt%) was added to the prepared raw material to impart porosity and air permeability, and wheat bran powder (about 9 wt%) was mixed in to be used as a nutrient source for the mycelium. Glycerol (about 2 wt%) was added as a plasticizer to ensure flexibility of the mixture, and sodium alginate (about 4 wt%) and calcium carbonate (about 3 wt%) were added to act as hardening agents.

[0081] After demolding the sample molded in the mold, the wax-based water-dispersible emulsion coating solution prepared in Example 1 was applied to the surface of the composite material. The application was performed uniformly using a brush or a sprayer, and the coating thickness was controlled to be 10 mm or less. This was done to prevent the problem of the mycelial layer being damaged or lost if the coating solution were applied after the mycelium was fully cultured, and the coating layer was formed immediately after demolding, followed by culture.

[0082] The coated specimens were cultured for approximately 7 days under conditions of a carbon dioxide concentration of 5,000 to 10,000 ppm, a temperature of 20 to 30°C, and a relative humidity of 90 to 100%. During this process, it was confirmed that the mycelium diffused and grew to the inner and outer surfaces of the molded body, integrating the entire composite material, and that the mycelium grew to the outer side of the applied wax coating layer to form a three-layer structure (inner raw material layer - middle coating layer - outer mycelial layer). It was confirmed that the coating layer did not inhibit mycelial growth during culture, and that the formation of the outer layer of the mycelium occurred normally at a coating thickness of 10 mm or less.

[0083] After the culture was completed, the composite material was dried in a hot air dryer at a temperature ranging from 30 to 80°C. During the drying process, the wax emulsion contained in the coating layer gradually melted according to the melting point of each component (approximately 43 to 80°C), and as a result, a uniform wax film was rearranged across the entire surface, forming a protective coating layer with improved water resistance and moisture resistance. At this time, it was confirmed that the micropores of the composite material were partially filled during the melting and re-solidification process of the wax, which reduced moisture permeability and improved surface strength and moisture resistance.

[0084] Therefore, the process of the present embodiment formed a wax coating layer immediately after demolding the mycelial composite material, and subsequently induced the melting and rearrangement of the wax during the culture and drying process, thereby enabling the realization of a uniform surface coating layer with improved water resistance and moisture resistance without damaging the mycelial layer.

[0086] Experimental Example 1. Optimization of Melting Point and Dissolution Conditions of Coating Agent

[0087] Various wax components (carnauba wax, candelilla wax, soy wax, coconut wax, and beeswax) were included as the main coating agent in the water-dispersible wax coating composition prepared by the method of Example 1-1 to confirm the melting point of each emulsion and to confirm the time and temperature conditions for forming a uniform coating layer.

[0088] The main coating agents included in the emulsions used in the test consisted of carnauba wax, candelilla wax, soy wax, coconut wax, and beeswax. After applying 2 g of each emulsion evenly onto an aluminum dish, the time of melting start and complete melting was observed while increasing the temperature in 5℃ increments, and the results are shown in Table 3.

[0089] division Melting start temperature (°C) Complete melting temperature (°C) Restocking characteristics Carnauba wax 78~82 82~86 High crystallinity and rapid re-solidification Candelilla wax 68.5~72.5 68.5~72.5 Rapid solidification Soy wax 43~54 49~54 Slow inventory coconut wax 37~48 43~50 Slow inventory beeswax 41.7~45.5 62~70 Gradual inventory

[0090] As confirmed in Table 3, carnauba wax began melting at approximately 78 to 82°C and completely melted at 82 to 86°C, exhibiting very high crystallinity and rapid re-solidification characteristics. Candelilla wax underwent simultaneous melting and dissolution at approximately 68.5 to 72.5°C and showed relatively rapid solidification characteristics. Soy wax began melting slowly at approximately 43 to 54°C and completely melted at 49 to 54°C, while coconut wax began melting at 37 to 48°C and completely melted at 43 to 50°C; both waxes exhibited low melting points and a slow re-solidification tendency. Beeswax began melting at 41.7 to 45.5°C and completely melted at 62 to 70°C, and it was confirmed to exhibit gradual re-solidification.

[0091] Subsequently, in order to confirm the characteristics of the water-dispersible wax coating composition according to the melting temperature, the appearance and uniformity of the coating layer were confirmed after melting and re-hardening at a temperature in the range of 40 to 80°C, and the results are shown in Table 4.

[0092] Main coating agent Temperature (°C) uniformity Flowability discoloration moisture resistance Overall evaluation note Carnauba wax 50 △ ◎ ◎ △ Insufficient melting Poor melting at low temperatures 60 ○ ○ ◎ ○ Good Partial melting 70~75 ◎ ○ ○ ◎ optimal Uniform film formation, no discoloration Candelilla wax 40 △ ◎ ◎ △ error Low temperature solidification 50~60 ◎ ◎ ◎ ◎ optimal Excellent uniformity and gloss ≥65 △ △ △ ○ Supermelting Flow generation Soy wax 40 ○ ◎ ◎ △ error Film weakness 50~60 ◎ ◎ ◎ ◎ optimal homogeneous film formation ≥65 △ △ ○ ○ commonly Possibility of overmelting coconut wax 40 ○ ◎ ◎ △ error Existence of unmelted parts 50~60 ◎ ◎ ◎ ◎ optimal Flexible homogeneous membrane ≥65 △ △ ○ ○ commonly Increase in flow beeswax 50 ○ ○ ◎ ○ Good Melting begins 60~65 ◎ ○ ◎ ◎ optimal Maintaining a uniform membrane ≥70 △ × △ ○ error Overmelting, discoloration

[0093] As confirmed in Table 4, under the 40℃ condition, numerous pores and cracks occurred due to insufficient initial curing, and in the 50 to 60℃ range, a smooth and uniform coating layer was formed in most waxes. In the 60 to 70℃ range, deterioration in appearance was observed due to increased flowability in some low-melting point waxes, and in the 70 to 80℃ range, excessive flow and discoloration of the substrate occurred in waxes, particularly excluding carnauba wax.

[0094] Overall, it was confirmed that low-melting-point waxes (soy, coconut, candelilla) formed the most uniform film at 50 to 60°C, and high-melting-point waxes (carnauba, beads) exhibited the most stable coating quality at approximately 55 to 75°C.

[0095] In addition, to confirm the characteristics of the water-dispersible wax coating composition according to the melting time, the results of checking the appearance and uniformity of the coating layer after melting and re-solidifying the composition at different melting times are shown in Table 5.

[0096] Main coating agent hour uniformity Flowability discoloration moisture resistance Overall evaluation note Carnauba wax 1 h ○ ○ ○ ○ commonly Fast coagulation, good appearance 1.5 h ○ △ ○ ◎ commonly Tendency to overmelt, but appearance is good ≥2 h △ × △ ○ error Flow and discoloration Candelilla wax 1 h ○ ○ ◎ ○ Good Start of homogeneous film formation 1.5~2 h ◎ ◎ ◎ ◎ optimal Excellent gloss and moisture resistance ≥2 h △ × △ ○ error Flow generation Soy wax 1 h ○ ○ ◎ ○ Good Non-uniform coating thickness 1.5~2 h ◎ ◎ ◎ ◎ optimal Excellent uniformity and gloss coconut wax 1 h ○ ○ ◎ ○ Good Similar tendencies to Soi 1.5~2 h ◎ ◎ ◎ ◎ optimal Good moisture resistance and appearance beeswax 1 h ○ ○ ○ ○ Good High adhesiveness 1.5 h ◎ ○ ◎ ◎ optimal Maintaining a uniform membrane ≥2 h △ × △ ○ error Overmelting occurs

[0097] ◎: Excellent / ○: Good / △: Average / ×: Poor

[0098] As confirmed in Table 5, when treated for 1 hour, carnauba wax solidified quickly and had a good appearance, whereas soy wax, coconut wax, candelilla wax, and beeswax formed the most stable continuous film when treated for 1.5 to 2 hours. In summary, for low-melting point waxes (soy, coconut, and candelilla), treatment at 50 to 60°C for 1.5 to 2 hours was the most stable condition, and for high-melting point waxes (carnauba and beeswax), a uniform film could be obtained when treated at 70 to 75°C for about 1 hour.

[0099] Accordingly, depending on the composition of the wax component included in the coating composition of the present invention, the coating process can generally secure optimal water resistance and appearance quality under conditions of 50 to 60°C and 1.5 to 2 hours, and it was confirmed that when a high melting point wax is included, conditions of 70 to 75°C and about 1 hour are most suitable.

[0101] Experimental Example 2. Evaluation of stability and performance according to changes in wax content in emulsion

[0102] In this experiment, the water-dispersible coating agent prepared in Example 1-1 was used as the basic composition, and the emulsion stability and coating performance were evaluated by varying the total wax content, including the main coating agent and auxiliary coating agent, in the emulsion.

[0103] The total wax content was adjusted to 30%, 40%, 50%, 57%, 70%, and 80% based on the weight of the emulsion, respectively. After undergoing drying and melting processes under the same conditions (50 to 60°C, 1.5 to 2 hours), the emulsion stability and coating quality were evaluated, and the results are shown in Table 6.

[0104] Total wax content (wt%) Emulsion stability Coating uniformity Gloss / Appearance Moisture resistance (WVP tendency) Overall evaluation note 30 △ △ △ △ error Phase separation, uneven coating 40 ◎ ○ ○ ○ Good Example 1-2 level, stable formation 50 ◎ ◎ ◎ ○ Good Excellent appearance and uniformity 60 ◎ ◎ ◎ ◎ optimal Excellent moisture resistance and gloss 70 ◎ ◎ ◎ ◎ optimal Maintains stability even at high concentrations 80 △ △ △ ○ error Wax aggregation and phase separation occur

[0105] ◎: Excellent / ○: Good / △: Average

[0106] As confirmed in Table 6 above, when the total wax content was 30 wt%, the emulsification stability of the emulsion decreased, and fine phase separation and non-uniformity were observed on the surface of the coating film. Under the 40 wt% condition, emulsification stability improved, and a uniform coating film was formed, resulting in good appearance and moisture resistance performance. At 50 wt% or higher, the density and gloss of the coating film improved, and particularly in the range of 60 to 70 wt%, while the stability of the emulsion was maintained, both moisture resistance (WVP reduction) and appearance quality reached optimal levels. On the other hand, at 80 wt% or higher, aggregation and phase separation of free-phase wax occurred again, and non-uniformity of the coating film and surface flow were observed.

[0107] Therefore, it was confirmed that the coating composition of the present invention is most stable in the range of 40 to 70 weight percent of total wax content in the emulsion, and can form a coating layer with excellent moisture resistance without phase separation or emulsification failure.

[0109] Experimental Example 3. Optimization of Coating Process and Drying Conditions for Composite Material Surfaces

[0110] The surface of a mycelium-based composite material was coated using the coating composition of Example 1, and changes in coating quality were evaluated according to drying temperature and time conditions. The coating composition was a water-dispersible wax emulsion including the compositional ranges of Examples 1-1 and 1-2, and the uniformity, flowability, discoloration, exposure of the mycelium layer, and moisture resistance of the coating layer were evaluated by varying the temperature range of 50 to 75°C and the heat treatment conditions of 0.5 to 2 hours, and the results are shown in Table 7.

[0111] Drying temperature (°C) Time (h) uniformity Flowability discoloration Mycelial exposure Moisture resistance (WVP tendency) Overall evaluation note 50 1.5 ○ ◎ ◎ ○ ○ Good Homogeneous film formation begins at low temperatures 55 1.5 ◎ ◎ ◎ ◎ ◎ optimal Excellent uniform film, gloss, and moisture resistance 60 2.0 ◎ ◎ ◎ ◎ ◎ optimal Formation of a highly adhesive, uniform film 65 1.0 ○ ○ ○ ○ ○ Good Partial flow occurs due to reduced viscosity ≥75 0.5 or higher △ × △ × △ error Non-uniform coating layer and exposure of mycelial layer due to overmelting

[0112] As confirmed in Table 7, when the drying temperature was in the range of 50 to 60°C, the coating layer was formed uniformly, and both moisture resistance (WVP reduction) and appearance gloss were excellent. In particular, the most stable and dense wax film was formed in the 55 to 65°C range, making the surface of the mycelium smooth and significantly reducing moisture absorption.

[0113] On the other hand, when the temperature was raised above 65°C, the viscosity of the coating layer decreased, causing localized flow, and at temperatures above 75°C, the wax layer melted excessively, resulting in the loss of the coating layer or the exposure of mycelia on some parts of the surface. This is attributed to the coating layer melting and flowing down in the direction of gravity, which consequently resulted in uneven thickness of the coating film and reduced moisture resistance.

[0114] Overall, the coating compositions formed the most uniform and moisture-resistant coating film when the drying temperature was set to 50 to 60°C and the treatment time to 1.5 to 2 hours, whereas at 75°C or higher, the coating layer was formed unevenly in all compositions, resulting in partial exposure of the mycelium or flow phenomena.

[0115] Accordingly, in the coating process of the present invention, it is preferable to maintain the drying temperature in the range of 50 to 60°C, which is about 10°C or lower than the melting point of the wax, thereby enabling the formation of a uniform wax coating layer without inhibiting the growth of the mycelium.

Claims

Claim 1 (S1) a step of preparing a water-dispersible emulsion comprising wax and a surfactant; (S2) a step of applying the water-dispersible emulsion to the surface of a mycelial composite material; (S3) a step of culturing the mycelial composite material coated with the water-dispersible emulsion at 20 to 40°C; and (S4) a step of treating the mycelial composite material coated with the water-dispersible emulsion at a temperature of 50 to 60°C for 1 to 2 hours to form a moisture-proof coating layer, wherein the wax comprises one or more selected from the group consisting of carnauba wax, candelilla wax, soy wax, coconut wax, and beeswax, and the wax comprises 40 to 70 weight% based on the total weight of the water-dispersible emulsion. Claim 2 delete Claim 3 In claim 1, the surfactant comprises (i) one or more nonionic surfactants selected from the group consisting of Tween 20, Tween 80, Span 20, Span 80, Lecithin, Sorbitan monostearate, Sorbitan tristearate, Polyoxyethylene stearate, Polyoxyethylene cetyl ether, PEG-40 Hydrogenated Castor Oil, Glyceryl stearate, Decaglyceryl monooleate, or Steareth-10·20; (ii) one or more anionic surfactants selected from the group consisting of sodium stearoyl lactylate, sodium lauryl sulfate, sodium lauryl ether sulfate, sodium stearate, potassium stearate, sodium oleate, sodium myristoyl glutamate, sodium lauroyl sarcosinate, sodium lauryl lactylate, or disodium laureth sulfosuccinate, or (iii) a combination thereof, for coating the surface of a mycelium-based composite material. method. Claim 4 A method for coating the surface of a mycelium-based composite material according to claim 1, wherein step (S1) comprises: (S1-1) dissolving a main coating agent and an auxiliary coating agent at 60 to 90°C for 1 to 30 minutes; (S1-2) adding a surfactant and preparing a mixture; (S1-3) adding distilled water preheated to 70 to 90°C to the mixture and stirring; and (S1-4) cooling at 20 to 30°C and stirring to stabilize the prepared emulsion. Claim 5 A method for coating the surface of a mycelium-based composite material according to claim 1, characterized in that the coating thickness of the coating layer is 10 mm or less. Claim 6 delete Claim 7 delete Claim 8 Mycelium-based composite material coated by the method of claim 1. Claim 9 The coated mycelium-based composite material according to claim 8, wherein the coated mycelium-based composite material has a mycelium layer on top of the coated layer.