Composite body and method for producing composite body

Abstract

Provided are: a composite which has excellent mechanical strength and moisture resistance and which has a good texture; and a method for producing the composite. The complex is characterized by comprising: mycelia of mushrooms; a binder which contains two or more carboxyl groups in one molecule and is bonded to the hypha; and a divalent or higher metal cation, the carboxyl groups being ionically crosslinked with each other via the metal cation. In addition, fibers are preferably provided. Further preferably, the fibers comprise cellulose.

Description

Technical Field

[0001] The present invention relates to a composite body and a method for manufacturing the composite body. Background Art

[0002] In recent years, products using natural materials have been sought on the market as products with minimal environmental impact. For example, Patent Document 1 discloses a cultured mycelium material comprising branched hyphae formed by breaking down one or more clumps and a binder having carboxyl groups. This structure provides a cultured mycelium material with excellent mechanical strength and aesthetic appeal.

[0003] However, binders containing carboxyl groups are hydrophilic. Consequently, cultured mycelium materials have low moisture resistance, leading to a decrease in mechanical strength when placed in high-humidity environments. Furthermore, there is room for improvement in the texture of cultured mycelium materials, and the applications of cultured mycelium materials are limited.

[0004] Therefore, a technology for realizing a composite body having excellent mechanical strength and moisture resistance and good texture is sought.

[0005] Patent Document 1: Japanese Patent Application No. 2022-534025 Summary of the Invention

[0006] The composite according to the application example of the present invention comprises: mycelia of mushrooms; an adhesive containing two or more carboxyl groups in one molecule and adhering to the mycelia; and divalent or higher valent metal cations, wherein the carboxyl groups are ionically cross-linked via the metal cations.

[0007] The method for manufacturing a composite body according to an application example of the present invention is a method for manufacturing a composite body according to an application example of the present invention, comprising: a step of hydrolyzing a sheet containing the hyphae; a step of bringing the hydrolyzed sheet into contact with an adhesive containing two or more carboxyl groups in one molecule to bond the sheet to the adhesive; and a step of bringing the sheet bonded with the adhesive into contact with the metal cations to ionically cross-link the carboxyl groups via the metal cations to obtain the composite body. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a process diagram showing a method for manufacturing a composite body according to an embodiment.

[0009] Figure 2 Table 1 shows the structure of the composites of the respective Examples and the evaluation results of the composites.

[0010] Figure 3Table 2 shows the structures of the composites of Examples and Comparative Examples and the evaluation results of the composites.

[0011] Figure 4 Table 3 shows the structure of the composites of the respective Examples and the evaluation results of the composites. DETAILED DESCRIPTION

[0012] Hereinafter, the composite body and the method for producing the composite body of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

[0013] 1. Complex

[0014] First, the complex according to the embodiment will be described.

[0015] The composite according to the embodiment includes mycelia of mushrooms, a binder, divalent or higher-valent metal cations, and fibers.

[0016] 1.1. Mycelium of Mushrooms

[0017] The hyphae of mushrooms are the fibrous structures that make up the mycelium of mushrooms. The types of mushrooms are not particularly limited, and examples thereof include Agaricus arvensis, Agrocybe brasiliensis, Amylomyces rouxii, species of the genus Amylomyces, Armillaria mellea, Aspergillus nidulans, Aspergillus niger, Aspergillus oryzae, Ceriporia lacerata, Coprinus comatus, Fibroporia vaillantii, Fistulina hepatica, Flammulina velutipes, Fomitopsis officinalis, Ganoderma sessile, Ganoderma tsugae, Hericium erinaceus, and the like. erinaceus), Hypholoma capnoides, Hypholoma sublaterium, Inonotus obliquus, Lactarius chrysorrheus, Macrolepiota procera, Morchella angusticeps, Myceliophthorathermophila, Neurospora crassa, Penicillium camembertii, Penicillium chrysogenum, Penicillium rubens, Phycomyces blakesleeanus, Pleurotus djamor, Pleurotus ostreatus, Polyporus squamosus, Psathyrella aquatica), Rhizopus microspores, Rhizopus oryzae, Schizophyllumcommune), Streptomyces venezuelae, Stropharia rugosoannulata, Thielavia terrestris, Ustilago maydis, Lentinula spp., Meripilus spp., Grifola spp., Leucopaxillus spp., Fomitopsis spp., Tricholoma spp., etc.

[0018] The hyphae of mushrooms can aggregate to form a mycelium. That is, some or all of the hyphae of the complex can be aggregates of hyphae. In the following description, the hyphae of mushrooms will also be referred to simply as "mycelium."

[0019] The average diameter of the hyphae is preferably set smaller than the average diameter of the fibers. This makes it easier to impart a smooth texture derived from the hyphae to the composite.

[0020] The average diameter of the hyphae is not particularly limited, but is preferably 0.1 μm to 5.0 μm, more preferably 0.3 μm to 3.0 μm. When the average diameter of the hyphae is within the above range, the texture of the composite can be particularly improved.

[0021] In addition, the average diameter of hyphae was measured as follows.

[0022] First, the complex was magnified and observed to capture an image of at least 100 hyphae within a single image. Next, at least 10 hyphae were randomly selected and their widths were measured. The average of these measurements was then used as the average hyphae diameter.

[0023] The average length of the hyphae is not particularly limited, but is preferably 0.001 mm to 3.0 mm, more preferably 0.010 mm to 2.0 mm, and even more preferably 0.050 mm to 1.0 mm. When the average length of the hyphae is within this range, for example, when the composite is formed into a sheet, the hyphae are oriented along the surface of the composite and are moderately intertwined with each other. This can significantly enhance the texture of the composite.

[0024] In addition, the average length of hyphae was measured as follows.

[0025] First, the complex was magnified and observed to capture an image of at least 100 hyphae within a single image. Next, at least 10 hyphae were randomly selected and their maximum length within the image was measured. The average of these measurements was then used as the average hyphae length.

[0026] 1.2. Adhesive

[0027] The binder contains two or more carboxyl groups within a molecule and adheres to the mycelium. "Adhering to the mycelium" means that chemical bonds exist between the carboxyl groups in the binder and organic groups in the mycelium. Specifically, the carboxyl groups in the binder form ester bonds with the hydroxyl groups in the mycelium. These ester bonds firmly bond the mycelium to one another.

[0028] Furthermore, when the composite contains fibers, the binder preferably bonds to the fibers in addition to the mycelia. In this case, the carboxyl groups in the binder also form chemical bonds, such as ester bonds, with the hydroxyl groups in the fibers. This allows for strong bonding between the fibers and between the mycelia and fibers.

[0029] In addition, the mycelium preferably contains chitin. Chitin is contained as a component of the cell wall of the mycelium. Chitin is a high molecular weight polysaccharide with N-acetylglucosamine as a structural unit, which has an acetamide group (-NHCOCH3) added to glucose. Since chitin has hydroxyl groups, the inclusion of chitin in the mycelium facilitates the formation of ester bonds with the adhesive.

[0030] Furthermore, the acetamide groups contained in chitin are deacetylated by the hydrolysis treatment described later, converting them into amino groups. These amino groups react with carboxyl groups to form amide bonds. Therefore, the hydrolysis treatment facilitates the formation of amide bonds between the mycelium and the adhesive. As a result, ester and amide bonds form between the mycelium and the adhesive, significantly enhancing the mechanical strength of the composite.

[0031] Furthermore, the carboxyl groups contained in the binder undergo ion crosslinking with other carboxyl groups via the metal cations described below. This allows the mycelia to crosslink with each other via the binder and the metal cations, thereby enhancing the mechanical strength of the composite. Furthermore, if the composite contains fibers, the fibers can be crosslinked with each other and with the mycelia via the binder and the metal cations, respectively. This can significantly enhance the mechanical strength of the composite.

[0032] The binder is not particularly limited as long as it is a compound containing two or more carboxyl groups in one molecule, but polycarboxylic acids or polycarboxylates are preferably used. Since they have multiple carboxyl groups, they can particularly improve the mechanical strength of the composite.

[0033] Examples of the polycarboxylic acid include carboxypolysaccharides and organic carboxylic acids.

[0034] Among them, examples of the carboxypolysaccharides include alginic acid, carboxymethyl amylose, and pectic acid.

[0035] Examples of the organic carboxylic acid include aliphatic dicarboxylic acids, aromatic dicarboxylic acids, dicarboxylic acids having a hydroxyl group, tricarboxylic acids, and amino acids having a plurality of carboxyl groups.

[0036] Examples of the aliphatic dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid. Examples of the aromatic dicarboxylic acid include phthalic acid, isophthalic acid, and terephthalic acid.

[0037] Examples of the dicarboxylic acid having a hydroxyl group include tartaric acid and malic acid.

[0038] Examples of the tricarboxylic acid include citric acid and aconitic acid.

[0039] Examples of amino acids having multiple carboxyl groups include aspartic acid and glutamic acid.

[0040] Polycarboxylates are salts formed by bonding carboxyl groups of polycarboxylic acids to monovalent cations. Examples of monovalent cations include alkali metal ions such as potassium ions and sodium ions, and ammonium ions.

[0041] Among them, the polycarboxylate is preferably an alkali metal salt of a carboxyl polysaccharide, more preferably an alkali metal salt of alginic acid, and even more preferably sodium alginate. Alginate alkali metal salts are salts formed by the combination of carboxyl groups of alginic acid and alkali metal ions. Alginate alkali metal salts, especially sodium alginate, undergo strong ion crosslinking with divalent or higher metal cations in a short period of time. In addition, because alginic acid contains multiple carboxyl groups, it is easy to form an ion crosslinked network. Therefore, by using an alkali metal salt of alginic acid as a binder, the mechanical strength of the composite can be particularly improved.

[0042] The binder content in the composite is preferably from 1.0% to 90% by mass, more preferably from 1.5% to 85% by mass, further preferably from 1.5% to 80% by mass, and particularly preferably from 5.0% to 80% by mass. When the binder content in the composite is within this range, sufficient mechanical strength can be achieved.

[0043] 1.3. Metal cations with a valence of two or more

[0044] Divalent or higher-valent metal cations facilitate ionic crosslinking between carboxyl groups. Ionic crosslinking allows for crosslinking between hyphae, between fibers, and between fibers and hyphae. This leads to gelation of the ionically crosslinked product, improving the mechanical strength of the composite. In the following description, "divalent or higher-valent metal cations" will be referred to simply as "metal cations."

[0045] The metal cation is not particularly limited, but ions of at least one metal element selected from the group consisting of Ca, Mg, Ba, Cu, Fe, Al, and Zn are preferably used. Since these ions are unlikely to affect the properties of the composite, they are suitable as metal cations added to the composite. This stabilizes the properties of the composite.

[0046] Furthermore, metal cations help suppress the reactivity of carboxyl groups. Since carboxyl groups are hydrophilic, when metal cations interact with carboxyl groups in the binder, they can suppress the hydrophilicity of the composite, thereby improving the moisture resistance of the composite.

[0047] The content of metal cations in the composite was measured as follows.

[0048] First, 10 mg of the complex was cut out as a test piece. Next, the test piece was immersed in 10 mL of a 30% by mass sodium hydroxide aqueous solution. Thus, the metal cations contained in the test piece were eluted and dissolved. Next, the dissolved solution containing the metal cations was quantitatively analyzed using high performance liquid chromatography (HPLC) to measure the concentration of the metal cations. The obtained concentration was used as the content of the metal cations in the complex.

[0049] The content of metal cations in the composite measured in this way is preferably 3×10 -6 mol / L and above 170×10 -6 mol / L or less, more preferably 5×10 -6 mol / L and above 100×10 -6 mol / L or less, more preferably 10×10 - 6 mol / L and above 80×10 -6 mol / L or less.

[0050] By setting the metal cation content within the above range, the amount of metal cations relative to the binder can be optimized, thereby substantially improving the moisture resistance of the composite and preventing the occurrence of undesirable elution of excess metal cations that are not retained by the composite.

[0051] If the metal cation content is below the lower limit, the amount of metal cations may be insufficient relative to the binder, potentially reducing the moisture resistance of the composite. On the other hand, if the metal cation content exceeds the upper limit, the amount of metal cations may be excessive relative to the binder. In such cases, the excess metal cations may dissolve from the composite.

[0052] 1.4. Fiber

[0053] The composite may contain fibers. By adding fibers, the mechanical strength of the composite can be further improved.

[0054] The fiber is not particularly limited, and a wide range of fiber materials can be used. Examples of the fiber include natural fibers such as animal fibers and plant fibers, and chemical fibers such as organic fibers, inorganic fibers, and organic-inorganic composite fibers. Specifically, it is preferred to use at least one selected from the group consisting of cellulose, silk, wool, cotton, hemp, kenaf, flax, ramie, jute, abaca, sisal, conifers, and broadleaf trees. These fibers can be used alone or in combination, or as regenerated fibers that have been purified.

[0055] Examples of fiber raw materials include waste paper and waste cloth, as long as they contain at least one of the aforementioned fibers. Furthermore, the fibers may be subjected to various surface treatments. The fibers may be pure or contain a variety of components, including impurities, additives, and other ingredients.

[0056] Among them, fibers containing cellulose are more preferred. Cellulose contains a large number of hydroxyl groups in its molecular structure. Therefore, it is easy to react with the binder, thereby easily improving the mechanical strength and moisture resistance of the composite.

[0057] The average fiber diameter is not particularly limited, but is preferably larger than the average diameter of the hyphae. Specifically, it is preferably 1.0 μm to 20.0 μm, and more preferably 3.0 μm to 15.0 μm. When the average fiber diameter is within this range, the mechanical strength of the composite can be particularly improved.

[0058] In addition, the average diameter of the fibers is measured as follows.

[0059] First, the composite is magnified and observed to capture an image of at least 100 fibers. Next, at least 10 fibers are randomly selected and their widths are measured. The average of these measurements is then taken as the average fiber diameter.

[0060] The average fiber length is not particularly limited, but is preferably 0.001 mm to 5.0 mm, more preferably 0.002 mm to 3.0 mm, and even more preferably 0.003 mm to 2.0 mm. When the average fiber length is within this range, the fibers are oriented along the surface of the composite, for example, and the fibers are appropriately intertwined with each other. This can significantly improve the mechanical strength of the composite.

[0061] In addition, the average length of the fibers was measured as follows.

[0062] First, the composite is magnified and observed to capture an image of at least 100 fibers within a single image. Next, at least 10 fibers are randomly selected and their maximum length within the image is measured. The average of these measurements is then taken as the average fiber length.

[0063] 1.5. Additives

[0064] Furthermore, the composite may contain any additives. Examples of such additives include plasticizers, stabilizers, antioxidants, ultraviolet absorbers, lubricants, flame retardants, antistatic agents, and fillers, and one or more of these additives may be used.

[0065] Examples of the plasticizer include sugar alcohols, vegetable oils, adipate plasticizers, phthalate plasticizers, trimellitate plasticizers, polyester plasticizers, (meth)acrylate polymers, ethylene copolymer elastomers, chlorinated polyethylene (CPE), (meth)acrylic resins (PMMA), polystyrene resins (PS), polyvinyl acetate resins (PVAc), acrylonitrile-butadiene rubber (NBR), and styrene-butadiene rubber (SBR).

[0066] Examples of the sugar alcohol include maltitol, lactitol, tetraitol, pentitol, hexitol, erythritol, sorbitol, xylitol, mannitol, and glycerin.

[0067] Examples of the vegetable oil include epoxidized vegetable oils such as epoxidized soybean oil (ESBO) and epoxidized linseed oil (ELSO).

[0068] The composite preferably contains glycerin or vegetable oil. By containing these, the softness of the composite can be improved. As a result, the texture of the composite can be further improved.

[0069] The content of the plasticizer in the composite is not particularly limited, but is preferably 10.0% by mass or less, more preferably 0.1% by mass or more and 7.0% by mass or less, and even more preferably 0.5% by mass or more and 4.0% by mass or less. This allows for a composite having both mechanical strength and flexibility to be obtained.

[0070] 1.6. Composite Forming

[0071] The composite is formed by, for example, mixing hyphae, a binder, metal cations, and fibers and heating the mixture. Heating the mixture further promotes the formation of chemical bonds between hyphae, between hyphae and fibers, and between fibers.

[0072] The mixing ratio of mycelia, binder, metal cations, and fibers in the composite can be appropriately set depending on the application and desired performance of the composite. The mixing ratio of mycelia, binder, metal cations, and fibers can be expressed, for example, by the total content of binder and metal cations in the composite and the ratio of mycelia to fiber content.

[0073] The total content of the binder and metal cations in the composite is preferably from 1.0% to 90.0% by mass, more preferably from 1.5% to 85.0% by mass, even more preferably from 1.5% to 80.0% by mass, and particularly preferably from 5.0% to 80.0% by mass. When the total content of the binder and metal cations in the composite is within this range, the mixing ratio of mycelium, binder, metal cations, and fibers is optimized, and sufficient mechanical strength, moisture resistance, and texture can be achieved.

[0074] Furthermore, the mass ratio of mycelia to fiber is preferably 0.10 to 9.0, more preferably 0.20 to 5.0, and even more preferably 0.30 to 3.0. When the ratio of mycelia to fiber is within this range, a balance between high mechanical strength and good texture can be achieved in the composite.

[0075] If the mass ratio of mycelia to fiber is below the lower limit, the texture of the composite may be reduced. On the other hand, if the mass ratio of mycelia to fiber exceeds the upper limit, the mechanical strength of the composite may be reduced.

[0076] 1.7. Dispersion of structural elements in a complex

[0077] In the composite, the binder and metal cations are preferably dispersed in the hyphae and fibers. The dispersed state refers to a state in which the binder and metal cations are dispersed between the hyphae, between the fibers, and between the hyphae and the fibers. The binder and metal cations physically and chemically crosslink the hyphae, between the fibers, and between the hyphae and the fibers, thereby fixing their positional relationships. This fixes / maintains the external shape of the composite, allowing the composite to maintain a desired shape, such as a sheet. Furthermore, by allowing the hyphae and fibers to expand in an intertwined manner, the composite can be given a good texture.

[0078] Furthermore, unbound mycelium and fibers may be present in the composite, and their proportion can be adjusted by adjusting the binder and metal cation dosage. The greater the unbound mycelium and fibers, the more easily deformable the composite will be. Furthermore, the greater the bound portions, the higher the rigidity and mechanical strength of the composite will be.

[0079] 1.8. Use of the complex

[0080] The composite can be formed into various shapes as needed. It can be formed into two-dimensional shapes such as sheets, plates, and meshes, or three-dimensional shapes such as blocks, rods, and spheres. Typical examples of composites include paper, nonwoven fabrics, wallpaper, wrapping paper, colored paper, drawing paper, fiberboard, filters, liquid absorbents, sound absorbers, cushioning materials, and mats.

[0081] The composite according to the present embodiment is excellent in mechanical strength, moisture resistance, and texture, and is therefore particularly suitable as a natural material such as a leather substitute (artificial leather).

[0082] 2. Method for manufacturing the composite

[0083] Next, a method for producing the composite body according to the embodiment will be described.

[0084] Figure 1 It is a process diagram showing the structure of the method for manufacturing the composite body according to the embodiment.

[0085] Figure 1 The composite manufacturing method shown includes a hydrolysis step S102 , a bonding step S104 , and a cross-linking step S106 .

[0086] 2.1. Hydrolysis process

[0087] In the hydrolysis step S102, first, a sheet containing mycelium is prepared. The sheet containing mycelium is formed by, for example, collecting a large amount of mycelium and molding or sheeting it into a sheet. In addition, the sheet may be in the form of a flat plate or may be molded into a predetermined shape. The mycelium may be a defibrated product of mycelium. Mycelium is an aggregate of mycelium. For defibration of mycelium, a method such as applying mechanical energy may be used. In particular, by using a defibrator, mycelium can be defibrated while suppressing significant damage to the mycelium to obtain mycelium. The defibration method may be a wet method, but a dry method is preferably used. A dry method refers to a method in which defibration is performed in a gas such as the atmosphere rather than in a liquid such as water. As for the defibrator, it is preferred to use an impeller mill capable of dry defibration.

[0088] Next, the sheet containing mycelium is subjected to a hydrolysis treatment. This hydrolysis treatment hydrolyzes the components that make up the mycelium, increasing the reactivity between the mycelium and the adhesive. Specifically, if the mycelium contains chitin, the acetamide groups within the chitin are deacetylated during the hydrolysis treatment, converting them into amino groups. These amino groups react with carboxyl groups to form amide bonds. Therefore, the hydrolysis treatment allows for the formation of amide bonds between the mycelium and the adhesive, significantly enhancing the mechanical strength of the composite.

[0089] As the hydrolysis treatment, for example, a treatment in contact with an alkaline solution, a treatment in which the product is decomposed by an enzyme, etc. can be cited. Among them, a treatment using an alkaline solution is preferably used. Deacetylation can be carried out particularly efficiently by using an alkaline solution. As the alkali used in the alkaline solution, for example, sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, sodium phosphate, ammonium hydroxide, etc. can be cited. Moreover, the alkaline solution preferably uses an aqueous solution thereof. The alkali concentration in the alkaline solution is not particularly limited, but is preferably 5% by mass or more and 90% by mass or less, more preferably 10% by mass or more and 50% by mass or less, and further preferably 20% by mass or more and 40% by mass or less. By setting the alkali concentration within the range, deacetylation of chitin can be carried out particularly efficiently.

[0090] The mass of the alkali used in the hydrolysis treatment of 1 g of mycelium is not particularly limited, but is preferably 3 g or more, more preferably 5 g or more and 100 g or less, and even more preferably 10 g or more and 50 g or less. By setting the mass of the alkali within this range, chitin deacetylation can be uniformly performed, and the increase in environmental load caused by excess alkaline solution can be suppressed.

[0091] The temperature of the alkaline solution in contact with the mycelia (treatment temperature) is not particularly limited, but is preferably 10° C. to 150° C., more preferably 50° C. to 130° C., and even more preferably 70° C. to 110° C. By setting the treatment temperature within this range, chitin deacetylation can be uniformly performed.

[0092] The time for which the mycelia and the alkaline solution are in contact (treatment time) is not particularly limited, but when carried out at the above-mentioned treatment temperature, it is preferably from 0.1 hours to 1000 hours, more preferably from 1 hour to 100 hours, and even more preferably from 3 hours to 50 hours. By setting the treatment time within the above range, chitin deacetylation can be performed efficiently and sufficiently.

[0093] 2.2. Bonding process

[0094] In the bonding step S104 , the hydrolyzed sheet is brought into contact with a binder containing two or more carboxyl groups in one molecule, thereby bonding the sheet and the binder.

[0095] For example, if the mycelium contains chitin, the hydrolyzed sheet contains hydroxyl groups and amino groups. When the adhesive is brought into contact with the sheet, ester bonds form between the carboxyl groups and the hydroxyl groups, and amide bonds form between the carboxyl groups and the amino groups, thereby bonding the sheet and the adhesive.

[0096] The method of bringing the adhesive into contact with the sheet is not particularly limited, and examples thereof include a method of spraying a solution containing the adhesive onto the sheet and a method of immersing the sheet in a solution containing the adhesive.

[0097] The solvent used in the solution containing the binder may be any liquid (solvent or dispersion medium) that can dissolve or disperse the binder, and examples thereof include water and various organic solvents.

[0098] The concentration of the adhesive in the solution containing the adhesive is not particularly limited, but is preferably 0.1% to 5.0% by mass, more preferably 0.3% to 1.0% by mass. If the concentration of the adhesive is within this range, the viscosity of the solution is optimized, allowing the adhesive to act evenly on the sheet in a short period of time. In addition, it is possible to prevent the amount of adhesive from being excessive and causing waste.

[0099] Furthermore, any additives may be added to the solution containing the binder as needed. Examples of the additives include condensing agents, antioxidants, stabilizers, and lubricants.

[0100] Among them, known amide condensing agents can be cited as condensing agents. Examples of amide condensing agents include carbodiimide condensing agents, carbonyldiimidazole condensing agents, triazine condensing agents, phosphonium condensing agents, urea condensing agents, and phosphoric acid condensing agents. By using such condensing agents, the reaction conditions required for forming an amide bond can be relaxed. In other words, compared to the case where no condensing agent is used, the reaction temperature can be lowered or the reaction time can be shortened. As a result, the bonding efficiency of the adhesive relative to the sheet material can be improved.

[0101] Examples of the carbodiimide condensing agent include dicyclohexylcarbodiimide (DCC), N-ethyl-N′-3-dimethylaminopropylcarbodiimide (EDC), and diisopropylcarbodiimide (DIPC).

[0102] Examples of the carbonyldiimidazole-based condensing agent include carbonyldiimidazole (CDI) and 1,2,4-triazole (CDT).

[0103] Examples of the triazine-based condensing agent include 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholine chloride (DMT-MM).

[0104] Examples of the phosphonium condensing agent include 1H-benzotriazol-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate (BOP) and 1H-benzotriazol-1-yloxytripyrrolidinylphosphonium hexafluorophosphate (pyBOP).

[0105] Examples of urea condensing agents include O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HATU), O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HBTU), and [(1-cyano-2-ethoxy-2-oxoethylideneaminooxy)-4-methylenemorpholino]dimethylammonium hexafluorophosphate (COMU).

[0106] Examples of the phosphoric acid-based condensing agent include diphenylphosphoryl azide (DPPA) and diethyl cyanophosphate (DEPC).

[0107] The amount of the condensing agent added is preferably adjusted to 0.01 molar equivalents to 2.0 molar equivalents, more preferably 0.05 molar equivalents to 1.5 molar equivalents, based on the molar equivalents of the active groups of the condensing agent relative to the amino groups.

[0108] Alternatively, after the solution containing the adhesive is brought into contact with the sheet material, the sheet material and the adhesive thereon may be heated as needed. Thus, the solvent or dispersion medium may be removed to promote drying. Furthermore, the reaction efficiency between the sheet material and the adhesive may be increased.

[0109] The heating temperature may be equal to or higher than the boiling point of the solvent or dispersion medium, and is preferably 60° C. to 200° C., and more preferably 80° C. to 150° C.

[0110] Furthermore, the sheet may contain fibers. When the sheet contains fibers, as described above, the binder also reacts with the fibers, and the hydroxyl groups contained in the fibers form ester bonds with the carboxyl groups contained in the binder.

[0111] 2.3. Cross-linking process

[0112] In the crosslinking step S106, the sheet material bonded with the adhesive is brought into contact with a divalent or higher metal cation. This allows the carboxyl groups to ionically crosslink with each other via the metal cations, resulting in a composite. Furthermore, while the carboxyl groups contained in the adhesive contribute to the reaction with the mycelium and fibers, not all of them contribute to the reaction, and unreacted carboxyl groups may also exist. If such unreacted carboxyl groups remain in the composite, this can reduce the composite's moisture resistance.

[0113] Therefore, in this embodiment, the carboxyl groups are ionically cross-linked via metal cations. This can reduce unreacted carboxyl groups and, as a result, improve the moisture resistance of the composite.

[0114] The metal cations having a valence of two or more are supplied to the sheet as a solution, for example. The solution containing the metal cations is formed by, for example, dissolving a metal cationic substance in water. Examples of metal cationic substances include reactants of metal cations and anions, i.e., salts. Examples of anions are not particularly limited, but include chloride ions, nitrate ions, carbonate ions, sulfate ions, lactate ions, and the like. Examples of salts of metal cations having a valence of two or more and the aforementioned anions include calcium chloride, calcium lactate, ferric chloride, magnesium chloride, barium nitrate, and copper nitrate.

[0115] The concentration of the salt in the solution containing the metal cations is not particularly limited, but is preferably 0.005% to 0.50% by mass, more preferably 0.010% to 0.30% by mass. This allows the metal cations to uniformly react with the adhesive-bonded sheet in a short period of time.

[0116] Alternatively, after the solution containing the metal cations is brought into contact with the sheet, the sheet and the metal cations attached thereto may be heated as needed. This may remove the solvent or dispersion medium and promote drying. Furthermore, the reaction efficiency between the adhesive and the metal cations may be increased.

[0117] The heating temperature may be equal to or higher than the boiling point of the solvent or dispersion medium, and is preferably 60° C. to 200° C., and more preferably 80° C. to 150° C.

[0118] According to the above method, a composite body having excellent mechanical strength and moisture resistance and good texture can be produced.

[0119] 3. Effects of the above implementation methods

[0120] As described above, the composite material according to the above embodiment comprises: mushroom hyphae; a binder containing two or more carboxyl groups per molecule and binding to the hyphae; and a divalent or higher-valent metal cation. Furthermore, in the composite material according to the above embodiment, the carboxyl groups are ionically cross-linked via the metal cation.

[0121] With such a structure, a composite having excellent mechanical strength and moisture resistance and a good texture can be obtained.

[0122] Furthermore, the composite body according to the above embodiment further includes fibers.

[0123] With such a structure, a composite body having particularly high mechanical strength can be obtained.

[0124] Furthermore, in the composite according to the above embodiment, the fibers include cellulose.

[0125] According to such a structure, since cellulose contains a large number of hydroxyl groups in its molecular structure, it is easy to react with the binder, thereby easily improving the mechanical strength and moisture resistance of the composite.

[0126] Furthermore, in the composite according to the above embodiment, the metal cation is an ion of at least one metal element selected from the group consisting of Ca, Mg, Ba, Cu, Fe, Al, and Zn.

[0127] According to such a structure, the metal cations are less likely to affect the properties of the complex, and thus the properties of the complex can be stabilized.

[0128] Furthermore, in the composite according to the above embodiment, the binder contains a polycarboxylic acid or a polycarboxylate.

[0129] With such a structure, a composite body having particularly high mechanical strength can be obtained.

[0130] Furthermore, in the composite according to the above embodiment, the content of the binder is 1.5% by mass or more and 80.0% by mass or less.

[0131] According to such a structure, sufficient mechanical strength can be obtained in the composite body.

[0132] In addition, when 10 mg of the composite according to the above embodiment is immersed in 10 mL of a 30% by mass sodium hydroxide aqueous solution, the concentration of the eluted metal cations is 3×10 -6 mol / L and above 170×10 -6 mol / L or less.

[0133] According to such a structure, the moisture resistance of the composite can be sufficiently improved, and the occurrence of a problem in which excess metal cations are not retained by the composite and are eluted can be suppressed.

[0134] Furthermore, the complex according to the above embodiment further contains glycerin or vegetable oil.

[0135] According to such a structure, the flexibility of the composite body can be improved, and as a result, the texture of the composite body can be further enhanced.

[0136] Furthermore, in the composite according to the above embodiment, the mycelium contains chitin, and the binder forms an amide bond with the mycelium.

[0137] According to such a structure, the mechanical strength of the composite body can be particularly improved.

[0138] The method for producing a composite according to the above embodiment comprises a hydrolysis step S102, a bonding step S104, and a crosslinking step S106. In the hydrolysis step S102, a sheet containing mycelium is hydrolyzed. In the bonding step S104, the hydrolyzed sheet is brought into contact with a binder containing two or more carboxyl groups per molecule, thereby bonding the sheet and the binder. In the crosslinking step S106, the binder-bonded sheet is brought into contact with metal cations, thereby ionically crosslinking the carboxyl groups via the metal cations to produce a composite.

[0139] According to such a structure, a composite body having excellent mechanical strength and moisture resistance and good texture can be produced.

[0140] While the composite and method for producing the composite of the present invention have been described above based on preferred embodiments, the present invention is not limited thereto. For example, the composite of the present invention may be a composite in which various components of the aforementioned embodiments are replaced with arbitrary structures having the same function, or a composite in which arbitrary structures are added to the aforementioned embodiments.

[0141] Furthermore, the method for producing the composite of the present invention may be a method in which a step for an arbitrary purpose is added to the above-mentioned embodiment.

[0142] Example

[0143] Next, specific examples of the present invention will be described.

[0144] 4. Fabrication of the Complex

[0145] Example 1

[0146] First, 1 g of a sheet containing mycelia was subjected to a hydrolysis treatment. The hydrolysis treatment was performed by immersing the sheet in 100 mL of an alkaline solution at 100° C. for 4 hours. The alkaline solution used was a 30% by mass sodium hydroxide aqueous solution.

[0147] Next, 1 g of sodium alginate as a binder was dissolved in 200 mL of pure water to prepare a sodium alginate aqueous solution.

[0148] Next, a sodium alginate aqueous solution was evenly sprayed onto the hydrolyzed sheet to allow it to penetrate. The sheet was then placed in a thermostatic bath and heated at 100° C. until it was dry.

[0149] Next, 7.5 mg of calcium chloride as a salt containing a metal cation was dissolved in 30 mL of pure water to prepare a calcium chloride aqueous solution.

[0150] Next, the sheet impregnated with the sodium alginate aqueous solution was uniformly sprayed with a calcium chloride aqueous solution to allow the sheet to penetrate. The sheet was then placed in a thermostatic bath and heated at 100° C. until dry. In this manner, the composite of Example 1 was obtained.

[0151] 4.2. Examples 2 to 21 and Comparative Examples 1 to 4

[0152] In addition to making the composite Figure 2 (Table 1), Figure 3 (Table 2) or Figure 4 Except for the changes shown in Table 3, the composites of Examples 2 to 21 and Comparative Examples 1 to 4 were obtained in the same manner as in Example 1. Details of the components used in the production of the composites are as follows.

[0153] Mycelium (Shiitake mushroom, average diameter 3.0 μm, average length 0.1 mm)

[0154] Mycelium (polypore, average diameter 5.0 μm, average length 0.5 mm)

[0155] Fiber (cellulose, average diameter 30 μm, average length 1.0 mm)

[0156] 5. Evaluation of the Complex

[0157] 5.1. Tensile index

[0158] First, the composite was punched out to produce test pieces. Next, the test pieces were subjected to a tensile properties test in accordance with JIS P 8113:2006 using an Autograph AGC-X 500N (manufactured by Shimadzu Corporation) to determine the tensile index. The obtained values were then evaluated against the following evaluation criteria. The "reference value" in the evaluation criteria refers to the tensile index measured for the composite of Comparative Example 4. The evaluation results are shown in the tables.

[0159] A: More than 150% of the reference value

[0160] B: 125% or more and less than 150% of the reference value

[0161] C: 100% or more and less than 125% of the reference value

[0162] D: Less than 100% of the reference value

[0163] 5.2.Moisture resistance

[0164] First, cut the composite into a rectangular shape of 2cm×1cm×1cm to make a test piece. Lay an aluminum plate inside a constant temperature and humidity chamber and place the test piece at the four corners. Apply a pressure of 0.01MPa by placing an aluminum plate weighing 800g on it. After measuring the initial gap between the aluminum plates, heat and humidify the constant temperature and humidity chamber to 60℃ 90%RH. After 120 hours, measure the gap between the aluminum plates again and calculate the displacement rate (compression creep rate) from the initial gap. Then, evaluate the calculated values according to the following evaluation criteria. The evaluation results are shown in the tables.

[0165] A: Compression creep rate is less than 5%

[0166] B: Compression creep rate is 5% or more and less than 10%

[0167] C: Compression creep rate is 10% or more and less than 20%

[0168] D: Compression creep rate is more than 20%

[0169] 5.3. Texture

[0170] The composite was subjected to a sensory evaluation by 10 assessors (evaluators). The sensory evaluation was conducted in accordance with the sequential method of sensory evaluation analysis of JIS Z 9080:2004. Specifically, the 10 assessors evaluated the feel of the surface of the composite with reference to the 9 levels of liking specified in JIS Z 9080:2004. In addition, the tactile feel particularly refers to the smoothness and the goodness of the tactile feel. The obtained liking was then evaluated against the following evaluation criteria. The evaluation results are shown in the tables. In addition, regarding the 9-level liking, 9 represents the most liked and 1 represents the least liked.

[0171] A: Like level is 8 to 9

[0172] B: Like level 6 to 7

[0173] C: Like level 4 to 5

[0174] D: Like level 1 to 3

[0175] 5.4. Inspection

[0176] according to Figure 2 (Table 1), Figure 3 (Table 2) and Figure 4 The evaluation results shown in (Table 3) confirmed the following.

[0177] By including mushroom mycelium, a binder, and divalent or higher metal cations, a composite with excellent mechanical strength, moisture resistance, and texture can be achieved;

[0178] In particular, by adding an appropriate amount of mushroom mycelium, the texture of the complex can be improved;

[0179] In particular, by adding an appropriate amount of divalent or higher-valent metal cations, the moisture resistance of the composite can be improved.

[0180] Explanation of symbols

[0181] S102 Hydrolysis process

[0182] S104 bonding process

[0183] S106 cross-linking process.

Claims

1. A complex, characterized in that have: Mycelium of mushrooms; an adhesive comprising two or more carboxyl groups in one molecule and adhering to the hyphae; Metal cations with a valence of two or more, The carboxyl groups are ionically cross-linked with each other via the metal cations.

2. The complex according to claim 1, wherein Also has fiber.

3. The complex according to claim 2, wherein The fibers comprise cellulose.

4. The complex according to claim 1 or 2, wherein The metal cation is an ion of at least one metal element selected from the group consisting of Ca, Mg, Ba, Cu, Fe, Al, and Zn.

5. The complex according to claim 1 or 2, wherein The binder comprises a polycarboxylic acid or a polycarboxylate.

6. The complex according to claim 1 or 2, wherein The content of the binder is 1.5% by mass or more and 80.0% by mass or less.

7. The complex according to claim 1 or 2, wherein When 10 mg of the composite was immersed in 10 mL of a 30% by mass sodium hydroxide aqueous solution, the concentration of the dissolved metal cations was 3×10 -6 mol / L and above 170×10 -6 mol / L or less.

8. The complex according to claim 1 or 2, wherein Also contains glycerin or vegetable oil.

9. The complex according to claim 1 or 2, wherein The mycelium contains chitin, The adhesive forms an amide bond with the hyphae.

10. A method for producing a composite body, which is the method for producing a composite body according to claim 1, characterized in that: have: a step of hydrolyzing the sheet material containing the mycelium; a step of bringing the hydrolyzed sheet into contact with the adhesive containing two or more carboxyl groups in one molecule to bond the sheet and the adhesive; A step of bringing the sheet to which the binder is bonded into contact with the metal cations to ionically cross-link the carboxyl groups via the metal cations, thereby obtaining the composite.

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