Antifungal agent

Abstract

To provide a volatile antifungal agent that uses a naturally-derived material and has an excellent antifungal effect.SOLUTION: A volatile antifungal agent includes a material obtained by removing at least a part of essential oil and water content from a ligneous part and / or leaves of a tree of the genus Abies in the family Pinaceae.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a volatile fungicide.

Background Art

[0002] Conventionally, fungicides have been used for storing articles. For example, as a fungicide for clothes, optical products, documents, books, paintings, and antiques, a fungicidal member composed of a container having an opening, a vaporizable fungicide disposed therein, and a gas-permeable film for closing the opening has been proposed (Patent Document 1).

[0003] In particular, for storing fiber products, fur products, dolls, etc., an insect-proof component is used in combination or in mixture with a fungicide. For example, it is described that a fungicide such as O-phenylphenol, p-chloro-m-xylenol, 3-methyl-4-isopropylphenol, or allyl isothiocyanate is blended together with a vaporizable pyrethroid as an insect-proof component (Patent Document 2). Further, N-n-butylcarbamic acid-3-iodo-2-propynyl ester is described as a vaporizable antibacterial and fungicidal agent, and furthermore, disclosure is also made regarding its combined use with volatile insect repellents such as camphor, paradichlorobenzene, naphthalene, and empenthrin (Patent Document 3).

[0004] On the other hand, due to a shortage of successors and a decline in timber prices, the maintenance of mountain forests has become insufficient, and their abandonment has become a major problem. The maintenance of these mountain forests mainly consists of thinning and pruning branches. However, if the thinned wood and the branches and leaves fallen during pruning have no economic value and only incur costs, it is natural that such maintenance will be neglected. Attempts have been made to process the wood targeted for thinning, etc., into useful resources. For example, after the thinned wood is made into chips, it is steamed and used as livestock feed.

[0005] Therefore, in recent years, attempts have been made to process the wood targeted for thinning, etc., into useful resources. For example, after the thinned wood is made into chips, it is steamed and used as livestock feed.

[0006] Furthermore, the inventors have proposed attempts to effectively utilize the branches and leaves of such thinned timber. For example, they have proposed a harmful oxide remover (Patent Document 4) whose active ingredient is the fibrous portion obtained by subjecting the woody part and / or leaves of a tree to vacuum distillation while irradiating them with microwaves; a liquid absorbent (Patent Document 5) containing material from which some of the essential oil and some of the water have been removed from the woody part and leaves of a tree by vacuum distillation while irradiating them with microwaves; and a sleep quality improving material (Patent Document 6) consisting of the residue of vacuum microwave steam distillation treatment of the woody part and / or leaves of a tree. However, the antibacterial and antifungal properties of these fibrous components are unknown.

[0007] [Patent Document 1] Japanese Utility Model Publication No. Showa 61-187303 [Patent Document 2] Japanese Patent Application Publication No. 11-139903 [Patent Document 3] Japanese Patent Application Publication No. 5-085909 [Patent Document 4] Japanese Patent Publication No. 2015-160154 [Patent Document 5] Japanese Patent Publication No. 2018-117598 [Patent Document 6] Japanese Patent Publication No. 2022-35493 [Disclosure of the Invention] [Problems that the invention aims to solve]

[0008] The objective of this invention is to provide a volatile antifungal agent that has excellent antifungal effects while using naturally derived materials. [Means for solving the problem]

[0009] In view of the above problems, the present inventors diligently searched for antifungal agents and discovered that fibrous components obtained by drying the woody parts and / or leaves of trees have antifungal effects, thus completing the present invention.

[0010] In other words, the present invention provides a volatile fungicide characterized by containing a material from which at least a portion of the essential oils and moisture have been removed from the woody parts and / or leaves of trees of the genus Abies in the family Pinaceae. [Effects of the Invention]

[0011] The volatile antifungal agent of the present invention volatilizes and exhibits a high antifungal effect within the target space. [Brief explanation of the drawing]

[0012] [Figure 1] This figure shows a cross-sectional view of the apparatus used for the mold prevention test. [Figure 2] This figure shows a plan view of the apparatus used for the mold prevention test. [Modes for carrying out the invention]

[0013] The present invention is a volatile antifungal agent characterized by containing a material from which at least a portion of the essential oils and moisture have been removed from the woody tissue and / or leaves of trees of the genus Abies in the family Pinaceae.

[0014] The trees used as raw materials are those belonging to the fir genus of the pine family.

[0015] Trees belonging to the genus Abies in the family Pinaceae include Abies sachalinensis, Abies firma, Abies veitchii, Abies mariesii, Abies veitchii, Abies serrata, Abies balsamensis, Abies sachalinen and Abies sachalinensis. Abies sachalinensis is particularly preferred.

[0016] In the mildew-proof agent of the present invention, a material in which a part of essential oil and a part of moisture are removed from the xylem and / or leaves of the tree of the genus Abies in the Pinaceae family is used. The amount of the liquid (generally essential oil and moisture) contained in the material is less than the amount of the liquid contained in the fresh wood and fresh leaves, and it is in a drier state compared to the fresh wood and fresh leaves. However, residues such as essential oil (residual oil content) usually exist, and this residue is considered to contribute to the continuous mildew-proof function.

[0017] The material may be obtained by any method. For example, extraction or distillation treatments such as solvent extraction, vacuum distillation, and steam distillation are performed on the xylem and / or leaves of the tree of the genus Abies in the Pinaceae family, and the residue separated from the extract and distillate (hereinafter referred to as "residue of tree distillation etc. treatment") can be used.

[0018] In particular, those obtained by a method of removing (i.e., extracting) the essential oil component (and moisture) by distillation from the xylem and / or leaves of the tree of the genus Abies in the Pinaceae family under reduced pressure are preferably used. The distillation under reduced pressure may be carried out while irradiating with microwaves. As a method of distilling and extracting the essential oil component (and moisture) under reduced pressure while performing such microwave irradiation (hereinafter referred to as "reduced pressure steam distillation method"), a method of distilling and extracting the essential oil only with the moisture originally contained in the raw material by utilizing the property that microwaves directly heat water molecules is preferable. The residue obtained by the reduced pressure steam distillation method is easy to be pulverized, especially easy to be pulverized by mechanical processing, and thus is suitable for use as a powder. Details of the reduced pressure steam distillation method are described in, for example, Japanese Patent Application Laid-Open No. 2015-160154 (Patent Document 4) and International Publication No. WO2010 / 098440 pamphlet.

[0019] In this method, the pressure in the distillation tank may be set to 3 to 95 kPa, preferably 3 to 40 kPa, particularly preferably 3 to 20 kPa. The steam temperature at this time becomes 40 to 100 °C.

[0020] Under such conditions, by heating the xylem and / or leaves of trees of the genus Abies under reduced pressure with microwave irradiation, a fibrous component that is a residue from which part of the essential oil and part of the moisture have been removed (hereinafter referred to as "tree VMSD treatment residue") can be suitably used as a fungicide. Treatment residues such as tree VMSD treatment residue can be used as they are, but it is preferable to further perform a drying treatment to remove moisture at normal pressure. The drying temperature and drying time are not particularly limited, but for example, it can be carried out at 50 to 80°C for about 1 to 5 hours. The content of the remaining essential oil component is preferably 0.01 to 10% by mass, more preferably 0.1 to 5% by mass in the residue. Also, the remaining moisture is preferably 20% by mass or less in the residue.

[0021] In treatment residues such as tree VMSD treatment residue, the essential oil is not completely removed, and some essential oil components contained in the xylem and / or leaves of the tree remain, and it is considered that the essential oil contributes to the antifungal effect. It is presumed that the combined action of the remaining essential oil components and the porous structure of treatment residues such as tree VMSD treatment residue exhibits sustained release, and the antifungal effect is continuously exerted over a long period.

[0022] As the essential oil components remaining in treatment residues such as tree VMSD treatment residue, it is preferable to contain those with relatively high boiling points among monoterpenes, sesquiterpenes, diterpenes, etc. from the viewpoint of the sustainability of the effect. The essential oil remaining in the tree VMSD treatment residue preferably contains less monoterpenes and more sesquiterpenes, diterpenes and / or tetraterpenes. When the proportion of terpenes with large molecular weights such as sesquiterpenes and diterpenes is large, an excellent antifungal effect can be maintained over a long period.

[0023] The above-mentioned tree VMSD treatment residue and other tree distillation treatment residues can be used as fungicides as they are, but they may also be further finely ground into powder (hereinafter referred to as "tree VMSD treatment residue powder" and "tree distillation treatment residue powder"), in which case the average particle size is preferably 1 to 15 μm. If the average particle size is less than 1 μm, it may aggregate during molding, making it difficult to mold, and if it is greater than 15 μm, the fungicide effect may be inferior. A more preferable average particle size is 5 to 10 μm. Furthermore, if the maximum particle size of the tree VMSD treatment residue powder and other tree distillation treatment residue powder is too large, it may be difficult to form a film when making it into a sheet, as will be described later, so it is preferable that the maximum particle size is less than 100 μm. The average particle size and maximum particle size can be measured with a precision particle size distribution analyzer, and the average particle size is expressed as the median diameter (D50).

[0024] The method of precision grinding is not particularly limited, and conventionally known precision grinders can be used. Examples of precision grinders include turbo mills, jet mills, bead mills, blade mills, motor grinders, rotor mills, cutting mills, disc mills, and vibratory mills.

[0025] Tree VMSD treatment residue powder and other tree distillation treatment residue powders can be used in powder form, or in sheet form or compressed and molded into molded products such as hangers. They can also be dispersed in a suitable solvent to form a liquid formulation if necessary. Furthermore, they can be supported on a carrier to form a solid formulation.

[0026] When used as a solid agent, the carrier to which the agent is supported is not particularly limited, but examples include wood, cellulose, paper, rayon, polyethylene, polypropylene, polyester, polyurethane, wool, talc, clay, unglazed pottery, cloth, nonwoven fabric, silica, talc, activated carbon, silica gel, zeolite, cellulose beads, activated carbon, ceramics, etc. Sublimable carriers such as triisopropyltrioxane and cyclododecane can also be used.

[0027] Of these, preferred methods include mixing tree VMSD treatment residue powder or other tree distillation treatment residue powder with a material constituting a sheet-like material such as a nonwoven fabric, and forming a sheet together with the material and the tree distillation treatment residue powder, or applying a suspension containing tree distillation treatment residue powder to a sheet-like material such as a nonwoven fabric, and evaporating the liquid as needed to support the tree distillation treatment residue powder on a carrier.

[0028] When forming a sheet-like material, one particularly noteworthy method is to incorporate the tree distillation or other processing residue powder together with fibers to form a wet nonwoven fabric. By incorporating the tree distillation or other processing residue powder together with fibers, the powder can be relatively easily supported on the nonwoven fabric.

[0029] Known coating methods for applying a suspension to a sheet-like material include dip coater, spray coater, flow coater, die coater, roll coater, blade coater, rod coater, bar coater, and spin coater.

[0030] The antifungal agent of the present invention can be placed, for example, in closets, storage spaces, etc., to prevent the growth of mold on stored clothing, etc. This is thought to be because essential oil components remaining in the residue of tree distillation and other processing volatilize into the space, exhibiting a sustained antifungal effect. [Examples]

[0031] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. It is not something that should be done.

[0032] (Manufacturing of Product 1 of the present invention) Fir branches and leaves were crushed using a crushing machine (manufactured by KYB Manufacturing Co., Ltd.), and approximately 50 kg of the crushed material was placed in the distillation tank of a microwave steam distillation apparatus. While stirring, the pressure inside the distillation tank was maintained under reduced pressure conditions of approximately 20 kPa (steam temperature approximately 67°C), and microwave irradiation was performed for 1 hour. The generated steam (oil and water) was removed from the distillation tank by suction using a vacuum pump, and the fir VMSD treated residue was obtained.

[0033] The obtained fir VMSD-treated residue was dried with stirring at 60°C to 70°C for 2.5 to 3 hours using a low-temperature drying apparatus (manufactured by Yokoyama Engineering Co., Ltd.). After that, it was classified using a rotary sieve classifier (16 mesh, sieve opening 1.0 mm) to obtain coarse powder.

[0034] The obtained coarse powder was fed into a jet mill (supersonic jet pulverizer: manufactured by Nippon Pneumatic Mfg. Co., Ltd.) and subjected to grinding for approximately 4 hours to obtain approximately 81 kg of fir VMSD treatment residue powder (product 1 of the present invention) with an average particle size of 8 μm (maximum particle size less than 100 μm). The residual essential oil component content was 1.18% by mass. The average particle size and maximum particle size were measured using a precision particle size distribution analyzer (such as Beckman Coulter Multisizer). The essential oil component content was analyzed by gas chromatography after methanol extraction of product 1 of the present invention.

[0035] Example 1 The following mold spores were subjected to antifungal testing. (1) Cladosporium sphaerospermum NBRC6348 (hereinafter referred to as CS) (2) Penicillium citrinum NBRC6352 (hereinafter referred to as PC) (3) Aspergillus niger NBRC9455 (hereinafter referred to as AN)

[0036] (Creation of collodion glass) A solution of collodion (5%) and diethyl ether in a 1:1 ratio was prepared, and a washed glass slide (25 mm × 75 mm) was immersed in the solution for 1 minute. The glass slide was removed from the solution and dried for 1 minute to create collodion glass.

[0037] (Preparation of potato dextrose (PDB) liquid medium for fungal spore suspension) Potato dextrose (PDB) liquid culture medium for suspending each type of mold spore was prepared using sterile water to the following concentrations. For CS: PDB concentration 1% For PC: PDB concentration 40% For AN: PDB concentration 1.3%

[0038] (Preparation of mold spore suspension) 0.1 ml of a glycerin solution (80% glycerin, 20% water) for each mold was spread onto potato dextrose agar plates and incubated at 25°C for 14 days. Then, approximately 7 cm of mold was scraped off using a platinum loop and suspended in the respective potato dextrose liquid medium prepared above. Next, the suspensions were passed through a filter-filled tip to remove the hyphae and obtain the individual mold suspensions. The number of spores was measured at five locations using a hemocytometer, and the average value was calculated. The total number of spores was then determined using the following formula. Spore count (spores / ml) = Average spore count ÷ (4 × 10) -6 ) Based on the calculated spore count, the final number of spores in the suspension was 5.0 × 10⁶. 5 The solution was diluted to approximately 1 / ml.

[0039] (Antifungal test) A filter paper moistened with 1 ml of sterile water was placed on the lid side of a tall petri dish (with a diameter of 75 mm and a height of 120 mm, and an internal volume of 500 ml). Meanwhile, a collodion glass was placed in the center of the tall petri dish container as shown in Figure 2, and 5g of the present invention was placed around the collodion glass in a roughly circular pattern. Three drops of 0.01ml of spore suspension were then added. The lid was placed over the container, and the petri dish was sealed by wrapping it with Parafilm. The container was then incubated at 25°C for 18 hours. After culturing, 0.002 ml of lactophenol blue solution was added dropwise to stain the hyphae and spores. A slide glass was placed over the sample, and the number of spores and germinated spores were counted using a microscope at 100x magnification (10x eyepiece, 10x objective lens), and the average value from three locations was calculated. The inhibition rate was calculated using the following formula. For the blank, a model without the present invention installed was used. The results are shown in Table 1.

[0040]

number

[0041] [Table 1]

[0042] As is clear from Table 1, the present invention inhibited spore germination of all types of mold without contact with the target material, demonstrating excellent antifungal effects. [Industrial applicability]

[0043] As described above, the volatile antifungal agent of the present invention has excellent antifungal effects, and by installing it in closets, storage spaces, etc., it can prevent mold growth on stored clothing and other items.

Claims

1. A volatile fungicide characterized by containing a material from which at least a portion of essential oils and moisture has been removed from the woody part and / or leaves of a tree of the genus Abies in the family Pinaceae, wherein the tree of the genus Abies in the family Pinaceae is Abies sachalinensis, and the material is a powder from which at least a portion of essential oils and moisture has been removed by heating the woody part and / or leaves of Abies sachalinensis under reduced pressure with microwave irradiation, with an average particle size of 5 to 10 μm and a maximum particle size of less than 100 μm, and the target fungal species is at least one species from the group consisting of Cladosporium sphaerospermum (black mold) and Penicillium citrinum (blue mold).

2. The volatile antifungal agent according to Claim 1, wherein the content of essential oil components in the material is 0.1 to 5% by mass.

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