阅读说明：本技术 农用容器 (Agricultural container ) 是由 藤原祐介 池山昭弘 片野祥吾 于 2018-11-06 设计创作，主要内容包括：本发明提供一种对作用于呼吸的气体的浓度进行调节且进一步提高结露的抑制效果的农用容器。作为农用容器的包装袋(10、30)中,隔开容纳蔬果等农产品的容纳空间与外部空间的隔壁为薄膜。包装袋(10、30)具备CA薄膜(11)及多孔薄膜(12)。CA薄膜(11)含有酰基取代度在2.00以上且2.97以下的范围内的纤维素酰化物。多孔薄膜(12)形成为具有0.0050μm以上且5.0μm以下的范围内的平均孔径的多个孔沿厚度方向贯穿的状态。(The invention provides an agricultural container which adjusts the concentration of gas acting on breath and further improves the condensation inhibition effect. In packaging bags (10, 30) as agricultural containers, a partition wall that partitions a storage space for storing agricultural products such as vegetables and fruits from an external space is a thin film. The packaging bags (10, 30) are provided with a CA film (11) and a porous film (12). The CA film (11) contains a cellulose acylate having an acyl substitution degree in the range of 2.00 to 2.97. The porous thin film (12) is formed in a state where a plurality of pores having an average pore diameter in a range of 0.0050 [ mu ] m or more and 5.0 [ mu ] m or less penetrate in the thickness direction.)

1. An agricultural container in which at least a part of a partition wall partitioning a storage space for storing an object and an external space is a film, comprising:

a cellulose acylate film comprising a cellulose acylate having a degree of substitution of acyl group in a range of 2.00 or more and 2.97 or less: and

a porous film is formed in a state where a plurality of pores having an average pore diameter in a range of 0.0050 [ mu ] m or more and 5.0 [ mu ] m or less penetrate in a thickness direction.

2. The agricultural container of claim 1,

the cellulose acylate has an acetyl group.

3. The agricultural container of claim 1 or 2, wherein,

the cellulose acylate film has an area ratio of at least 10.0%.

4. The agricultural container of any one of claims 1 to 3, wherein,

the area ratio of the porous film is in the range of 0.1% to 20.0%.

5. The agricultural container of any one of claims 1 to 4,

the porous film is communicated with a plurality of holes in the thickness direction.

6. The agricultural container of any one of claims 1 to 5,

the accommodated matters are a seedbed and a seedling,

the porous film is disposed on a side surface of the bed in a standing posture.

7. The agricultural container of claim 6,

the porous film is disposed on each of the 1 st side surface and the 2 nd side surface that face each other.

8. The agricultural container of claim 6 or 7, wherein,

the cellulose acylate film is disposed on the top surface.

9. The agricultural container according to any one of claims 1 to 5, which is a bag formed with an opening into which the content is put.

Technical Field

The invention relates to an agricultural container.

Background

As an agricultural container for containing a growing object or agricultural products to be produced in the case of agricultural production, for example, there are a seedling raising container for containing seedlings to be grown and a packaging container such as a bag or a box for packaging agricultural products such as vegetables and fruits. As a package for agricultural products, MA (Modified atmosphere) package is known, which regulates oxygen (O) for the purpose of controlling respiration₂) And carbon dioxide (CO)₂) The concentration of (c).

As a packaging container for controlling the concentration of oxygen, carbon dioxide, water vapor, and the like, for example, patent document 1 describes a packaging material including a container formed of a polymer film and a breathable valve which is fastened to a mouth portion of the container by mechanical connection and allows breathing of fresh food. As materials for forming the polymer film of the container, polyethylene, polypropylene, polyethylene terephthalate, polyamide, polystyrene copolymer, cellophane, polylactic acid, cellulose acetate, thermoplastic starch, and derivatives thereof are described. The ventable valve includes a ring disposed around the mouth of the container and an outer peripheral surface of the container, and a ventable cap mechanically connected to the ring. The ventable lid has a plurality of perforations, in embodiments where bananas are packaged, the perforations are micro-perforations having a diameter of 200 μm or 250-300 μm.

Patent document 2 describes a package of garlic using a film made of a synthetic resin film or a semi-synthetic resin film, the film having an opening area of 3.1 × 10^-11～7.1×10^-8m²The opening area per 100g of garlic of (1.96 × 10) is 1.96^-9～5.59×10^-8m²100g, the oxygen concentration and the carbon dioxide concentration in the garlic-packed body are respectively in a predetermined range, and the oxygen transmission rate, the carbon dioxide transmission rate, and the carbon dioxide transmission rate/oxygen transmission rate are all in a predetermined range.

Further, patent document 3 describes a closed plant cultivation system capable of preventing invasion of bacteria. The plant cultivation system forms an inner space for accommodating a plant body such as a seedling by a non-porous hydrophilic film. Then, a part of the outer space side of the nonporous hydrophilic membrane is brought into contact with water or a solution disposed in the outer space.

Disclosure of Invention

Technical problem to be solved by the invention

In storage in an agricultural container, from the viewpoint of controlling respiration, it is preferable to suppress condensation in addition to adjusting the concentration of a gas such as carbon dioxide. This is because the suppression of dew condensation is effective for suppressing fogging of the inner surface of the agricultural container or for suppressing the generation and/or proliferation of mold in the agricultural container.

In this regard, although patent document 1 describes that the concentration of water vapor can be controlled, dew condensation occurs even when vegetables and fruits that emit a larger amount of water than the bananas described as the contents in patent document 1 are packed and/or when the vegetables and fruits are kept in cold for a long period of time. Similarly, in the packaging bag of the package of patent document 2, condensation occurs when vegetables and fruits having a large amount of moisture released therefrom are packaged and/or when the vegetables and fruits are kept in a cold state for a long period of time. In the cultivation system of patent document 3, dew condensation may occur on the inner surface of the nonporous hydrophilic film.

Accordingly, an object of the present invention is to provide an agricultural container that further improves the effect of suppressing dew condensation by adjusting the concentration of a gas that acts on respiration.

Means for solving the technical problem

In order to solve the above problems, an agricultural container according to the present invention includes a cellulose acylate film and a porous film, and at least a part of a partition wall that partitions a storage space for storing an object and an external space is a film. The cellulose acylate film contains a cellulose acylate having a degree of substitution of acyl group in a range of 2.00 or more and 2.97 or less. The porous film is formed in a state where a plurality of pores having an average pore diameter in a range of 0.0050 [ mu ] m or more and 5.0 [ mu ] m or less penetrate in the thickness direction.

The cellulose acylate preferably has an acetyl group.

The area ratio of the cellulose acylate film is preferably at least 10.0%. The area ratio of the porous film is preferably in the range of 0.1% to 20.0%.

The porous film preferably has a plurality of pores communicating with each other in the thickness direction.

The material to be stored is a seedbed or a seedling, and the porous film is preferably disposed on a side surface of the material to be stored in a standing posture with respect to the seedbed. The porous film is preferably disposed on each of the 1 st side and the 2 nd side which face each other. The cellulose acylate film is preferably disposed on the top surface.

Preferably a bag formed with an opening into which the contents are placed.

Effects of the invention

According to the present invention, the concentration of the gas is adjusted and the dew condensation is further suppressed.

Drawings

Fig. 1 is an explanatory view of a packaging bag embodying the present invention.

Fig. 2 is an end view in cross section of the porous membrane.

Fig. 3 is an explanatory diagram of a method of calculating the area ratio, and fig. 3(a) shows the 1 st sheet and fig. 3(B) shows the 2 nd sheet.

Fig. 4 is an explanatory view of a packaging bag according to another embodiment.

Fig. 5 is an explanatory diagram of a method of calculating the area ratio, and fig. 5(a) shows the 1 st sheet and fig. 5(B) shows the 2 nd sheet.

Fig. 6 is a schematic perspective view of a packaging box embodying the present invention.

Fig. 7 is an expanded explanatory view explaining a method of calculating the area ratio.

Fig. 8 is a schematic perspective view of a seedling raising device embodying the present invention.

Detailed Description

In fig. 1, a packaging bag 10, which is an example of an agricultural container, is a bag-shaped packaging container for packaging agricultural products, such as vegetables and fruits, and the agricultural products are stored and/or distributed in a state of being accommodated in an accommodating space inside the packaging bag 10. In the present embodiment, the agricultural products are vegetables and fruits, for example. In addition, the packaging bag 10 is not limited to packaging agricultural products, and can be used for agricultural production. For example, the packaging bag 10 can be used in a state of covering (wrapping) a seedling to be grown.

The packaging bag 10 is formed in a state in which 3 sides of 2 rectangular sheets as sheet-like films are joined to each other. The joint portion 10a, which is a portion to be joined, is provided on 2 sheets. The upper opening 10b in fig. 1 formed by the non-joined edges 1 serves as an entrance for placing vegetables and fruits as the object to be stored, and is sealed with an adhesive tape or the like, for example, during storage and/or distribution of the vegetables and fruits. The accommodation space is thereby sealed, and a sealed package is provided.

The packaging bag 10 can be used in both of a closed type packaging and an open type packaging, but is preferably packaged in a closed type packaging because contamination by viruses, bacteria, fungi (including mold), dust, and the like can be suppressed.

In this example, 2 sheets are joined by heat sealing, but the joining method is not limited to heat sealing, and for example, bonding using an adhesive tape may be used. The packaging bag 10 is formed by joining 2 sheets, but the packaging bag is not limited to this form. For example, a packaging bag having a joint portion and a folded portion may be obtained by folding 1 sheet of a rectangular shape, for example, at the center thereof and joining 2 sides.

The packaging bag 10 is an agricultural container formed into a bag shape before use, but may be an agricultural container formed into a bag shape when packaging, that is, when starting to use. As an example of this, there is a case where an agricultural container at least a part of which is formed of a film and which is formed in a cylindrical shape is formed in a bag shape by inserting an object to be contained into a hollow portion and then joining an opening at an end portion of the cylinder.

One sheet (hereinafter, referred to as a 1 st sheet) to be bonded is composed of a cellulose acylate film (hereinafter, referred to as a CA film) 11 and a porous film 12, and the other sheet (hereinafter, referred to as a 2 nd sheet) is composed of the CA film 11. In fig. 1, the sheet on the front side is drawn as a 1 st sheet, and the sheet on the back side is drawn as a 2 nd sheet. Thus, the packaging bag 10 includes the CA film 11 and the porous film 12, and is entirely formed of a film. In this example, the bonding portion 10a is formed of the CA film 11. Both the 1 st sheet and the 2 nd sheet may be constituted by the CA film 11 and the porous film 12.

In the 1 st sheet, the porous film 12 is disposed at a substantially central position surrounded by the CA film 11. However, the position of the porous film 12 is not limited to this example, and may be any position such as a position closer to the end of the joint 10a or a position closer to the opening 10 b. The porous film 12 is a rectangle whose long side is the horizontal direction in fig. 1. However, the shape of the porous film 12 is not limited to this example, and may be, for example, other polygonal shapes such as a square, a triangle, and a pentagon, a circle such as a perfect circle or an ellipse, an irregular shape, a slit shape extending in one direction, or the like. In this example, the outer periphery of the porous film 12 is joined to the CA film 11 in a state of being superimposed thereon by heat sealing. However, the overlapping area is small, and therefore, illustration is omitted in fig. 1.

Hereinafter, the CA film 11 and the porous film 12 will be described separately. The CA film 11 is formed of cellulose acylate. Cellulose acylate is esterified from a hydroxyl group of cellulose by a carboxylic acid, and thus has an acyl group. The CA film 11 contains (contains) cellulose acylate, and the degree of substitution of acyl groups of the cellulose acylate contained in the packaging bag 10 is in the range of 2.00 or more and 2.97 or less.

When vegetables and fruits are contained, moisture is released from the vegetables and fruits, and the moisture increases the humidity of the containing space, which is the inner space of the packaging bag 10. The increase in humidity increases the equilibrium water content of the CA film 11. The increase in the equilibrium water content causes the CA film 11 to absorb water. The moisture in the packaging bag 10 is reduced by the absorption of the water by the CA film 11, whereby the equilibrium water content of the CA film 11 is reduced and the water is released. The CA film 11 contains cellulose acylate having an acyl substitution degree within the above range, and therefore has a balanced water content having an appropriate moisture absorption and desorption property. Thus, even when the packaging bag 10 is packaged in a state in which the vegetables and fruits are sealed, the packaging bag 10 suppresses the occurrence of condensation on the inner surface, which is the inner surface of the packaging bag 10, while maintaining the storage space at a suitably high humidity level at which the dryness of the vegetables and fruits is suppressed. Further, even if the temperature and/or humidity of the external space (outside) changes, the change in humidity inside the packaging bag 10 is suppressed to be smaller than the change in outside. Further, the effect of suppressing the occurrence of condensation during the cold storage can be obtained, and the freezing storage can be continued for a long time such as 14 days. As a result, the production and proliferation of mold and the like can be suppressed, and the vegetables and fruits can be preserved in a fresh state for a long period of time. Further, discoloration of the vegetables and fruits can be suppressed by maintaining the environment at a suitably high humidity and suppressing dew condensation as described above. Similarly, when the packaging bag 10 is used for growing seedlings, condensation can be suppressed by the CA film 11, and as a result, seedlings grow well. Further, since the CA film 11 can maintain strength even in a high humidity environment, the fruit and vegetable can be protected even when the packaging bag 10 is left under high humidity, and the seedlings can be grown for a long period of time similarly to the case of raising seedlings.

The smaller the degree of substitution with acyl groups, the more the amount of water to be absorbed by the CA film 11 increases, and therefore the packaging bag 10 is easily deformed by this water absorption. Therefore, the degree of substitution with acyl groups of the cellulose acylate constituting the CA film is 2.00 or more. Further, theoretically, the upper limit of the degree of substitution with acyl groups is 3.00, but it is difficult to synthesize cellulose acylate having a degree of substitution with acyl groups exceeding 2.97. Therefore, the degree of substitution with acyl groups of the cellulose acylate constituting the packaging bag 10 is set to 2.97 or less.

The degree of acyl substitution of the cellulose acylate contained in the CA film 11 is more preferably in the range of 2.40 to 2.95, and still more preferably in the range of 2.70 to 2.95. As is well known, the degree of substitution with acyl groups is the ratio of the hydroxyl groups of cellulose to be esterified with carboxylic acids, i.e., the degree of substitution with acyl groups.

The acyl group of the cellulose acylate is not particularly limited, and may be an acetyl group having 1 carbon atom, or an acyl group having 2 or more carbon atoms. The acyl group having 2 or more carbon atoms may be an aliphatic group or an aryl group, and examples thereof include an alkylcarbonyl ester, an alkenylcarbonyl ester, an aromatic carbonyl ester, and an aromatic alkylcarbonyl ester of cellulose, each of which may have a further substituted group. Examples thereof include propionyl group, butyryl group, pentanoyl group, hexanoyl group, octanoyl group, decanoyl group, dodecanoyl group, tridecanoyl group, tetradecanoyl group, hexadecanoyl group, octadecanoyl group, isobutyryl group, tert-butyryl group, cyclohexanecarbonyl group, oleoyl group, benzoyl group, naphthylcarbonyl group, and cinnamoyl group. As the cellulose acylate, commercially available products can also be used. Specifically, CAP-482-20 (manufactured by Eastman Chemical Company) which is cellulose acetate propionate, CAB-381-20 (manufactured by Eastman Chemical Company) which is cellulose acetate butyrate, and the like can be given.

The cellulose acylate may have only 1 kind of acyl group or 2 or more kinds of acyl groups, but preferably at least 1 kind is an acetyl group. Since the cellulose acylate having an acetyl group absorbs moisture more easily, the effect of suppressing dew condensation and the like are further improved. Most preferred is a cellulose acylate in which all of the acyl groups are acetyl groups, that is, most preferred is a cellulose acylate of cellulose acetate.

The degree of acyl substitution can be determined by a conventional method. For example, the degree of acetylation (degree of acetyl substitution) is in accordance with ASTM which is a specification of ASTM International (American Society for testing and Materials): d-817-91 (test method for cellulose acetate, etc.) and the degree of acetylation. Further, the degree of acylation (degree of substitution with acyl group) distribution can also be measured by high-performance liquid chromatography. As an example of this method, in the measurement of the acetylation degree of cellulose acetate, a sample was dissolved in methylene chloride (also referred to as dichromethane), and the acetylation degree distribution was measured by a linear gradient from a mixed solution of methanol and water as an eluent (the mass ratio of methanol to water is 8: 1) to a mixed solution of methylene chloride and methanol (the mass ratio of methylene chloride to methanol is 9: 1) using a column Nova-Pak (registered trademark) phenyl (manufactured by waters corporation), and the acetylation degree distribution was determined by comparing calibration curves of different standard samples based on the acetylation degree. These measurement methods can be determined by referring to the methods described in japanese patent application laid-open No. 2003-201301. In the case where the CA film 11 contains (contains) an additive, the measurement of the acetylation degree of cellulose acylate is preferably based on the measurement by high-performance liquid chromatography.

In the present embodiment, the CA film 11 is produced by a known solution film-forming method, and a plasticizer is preferably added to the cellulose acylate having an acyl substitution degree in the above range in order to produce the C A film 11. Various known plasticizers can be used as the plasticizer for the cellulose acylate, and even if the plasticizer is used, condensation is suppressed and discoloration of the vegetable or fruit is suppressed. For example, it was confirmed that condensation was suppressed by forming an C A film 11 containing triphenyl acetate (TPP), diphenyl phosphate (BDP), and a cellulose acylate having an acyl substitution degree in the above range, placing vegetables and fruits in the thus-produced packaging bag 10, sealing the packaging bag, and storing the packaging bag in a refrigerated state at 5 ℃ for 14 days, and by confirming only a very small amount of condensation on the inner wall of the packaging bag. In addition, during the storage, it was confirmed that the vegetables and fruits were hardly discolored and kept fresh. As such, various plasticizers can be used as the plasticizer from the viewpoint of suppressing dew condensation. In addition, various known plasticizers can be used as the plasticizer as long as safety is confirmed in view of the fact that the storage target is vegetables and fruits.

The CA film 11 may contain at least one of an ester derivative of a sugar, an ester oligomer, and an acrylic polymer, in addition to the cellulose acylate having an acyl substitution degree within the above range. The ester derivative and the ester oligomer of the saccharide function as a plasticizer for cellulose acylate having an acyl substitution degree within the above range.

The ester derivative of the saccharide may be either one of an ester derivative of a monosaccharide and an ester derivative of a polysaccharide, and the CA film 11 may contain both of them. In view of the above safety, examples of the sugar include: monosaccharides such as glucose, galactose, mannose, fructose, xylose, and arabinose; polysaccharides such as lactose, sucrose, Nystose (Nystose), 1F-fructosyl Nystose, stachyose, maltitol, lactitol, lactulose, cellobiose, maltose, cellotriose, maltotriose, raffinose or kestose, gentiobiose, gentiotriose, gentiotetraose, xylotriose, galactosucrose. Preferably glucose, fructose, sucrose, kestose, nystose, 1F-fructosyl nystose, stachyose and the like, and more preferably sucrose and glucose. The polysaccharide may be produced by using an oligosaccharide, which is produced by allowing an enzyme such as amylase to act on starch, sucrose, or the like, and examples of the oligosaccharide include maltooligosaccharide, isomaltooligosaccharide, fructooligosaccharide, galactooligosaccharide, and xylooligosaccharide.

The monocarboxylic acid used for esterifying all or a part of the OH groups in the monosaccharide or polysaccharide structure is not particularly limited, and known aliphatic monocarboxylic acids, alicyclic monocarboxylic acids, aromatic monocarboxylic acids, and the like can be used. The carboxylic acid used may be 1 kind or a mixture of 2 or more kinds.

Preferred aliphatic monocarboxylic acids include: saturated fatty acids such as acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, caproic acid, heptanoic acid, caprylic acid, nonanoic acid, decanoic acid, 2-ethyl-hexanecarboxylic acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, heptadecanoic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, lignoceric acid, hexacosanoic acid, heptacosanoic acid, montanic acid, melissic acid, lacceric acid, etc.; unsaturated fatty acids such as undecylenic acid, oleic acid, sorbic acid, linoleic acid, linolenic acid, arachidonic acid, and octenoic acid; and alicyclic monocarboxylic acids such as cyclopentanecarboxylic acid, cyclohexanecarboxylic acid and cyclooctanecarboxylic acid.

Examples of the preferred aromatic monocarboxylic acid include aromatic monocarboxylic acids having 2 or more benzene rings such as benzoic acid and methylbenzoic acid in which an alkyl group or an alkoxy group is introduced into the benzene ring of benzoic acid, cinnamic acid, benzoic acid, biphenylcarboxylic acid, naphthalenecarboxylic acid, and tetrahydronaphthalenecarboxylic acid, and derivatives thereof, and benzoic acid and naphthalenecarboxylic acid are particularly preferred.

The ester oligomer is a relatively low molecular weight compound having a repeating unit including an ester bond between a dicarboxylic acid and a diol, and the number of the repeating unit is about several to 100, and is preferably an aliphatic ester oligomer. This is because the cellulose acylate acts more reliably as a plasticizer than the aromatic ester oligomer.

The molecular weight of the ester oligomer is preferably in the range of 500 to 10000. This is because the molecular weight of 500 or more improves the flexibility (flexibility) and/or heat sealability of the CA film 11 as compared with the case of less than 500, and the molecular weight of 10000 or less ensures the compatibility with cellulose acylate as compared with the case of more than 10000. The molecular weight of the ester oligomer is more preferably in the range of 700 to 5000, and still more preferably 900 to 3000.

The molecular weight of the ester oligomer has a molecular weight distribution, and therefore can be determined by a weight average molecular weight and/or a number average molecular weight by GPC (Gel permeation chromatography), a number average molecular weight measurement method by a terminal functional group amount measurement and/or an osmotic pressure measurement, a viscosity average molecular weight by a viscosity measurement, and the like. In the present embodiment, the hydroxyl group or the acid group of the ester is measured as the terminal functional group by a number average molecular weight measurement method.

In the ester oligomer, the dicarboxylic acid is more preferably a dicarboxylic acid having 2 to 10 carbon atoms, and the diol is more preferably a diol having 2 to 10 carbon atoms. Particularly, both the dicarboxylic acid and the diol are preferably aliphatic compounds. This is because the use of the aliphatic dicarboxylic acid and the aliphatic diol can impart flexibility to the CA film 11 and further improve the water content. In the present embodiment, the moisture content of the sample was measured by adjusting the humidity of the object to be measured at 25 ℃ and a relative humidity of 80% or 55% for 24 hours, then sampling 500mg, and determining the moisture content of the sample by using karl fischer moisture meter AQ-2200 manufactured by hiramumasangyo co. The dicarboxylic acid includes aromatic carboxylic acids such as phthalic acid, terephthalic acid, and isophthalic acid, and the aliphatic carboxylic acids include malonic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, azelaic acid, cyclohexanedicarboxylic acid, maleic acid, and fumaric acid. Examples of the aliphatic diol include ethylene glycol, 1, 2-propanediol, 1, 3-propanediol, 1, 2-butanediol, 1, 3-butanediol, 2-methyl-1, 3-propanediol, 1, 4-butanediol, 1, 5-pentanediol, 2-dimethyl-1, 3-propanediol (neopentyl glycol), 1, 4-hexanediol, 1, 4-cyclohexanediol, and 1, 4-cyclohexanedimethanol. It is also preferable to seal the terminal hydroxyl and/or acid groups of the ester oligomer by a monocarboxylic acid, a monoalcohol, or the like. Among these, preferred are oligomers having an ester of adipic acid and ethylene glycol as a repeating unit, oligomers having an ester of succinic acid and ethylene glycol as a repeating unit, and oligomers having an ester of terephthalic acid and ethylene glycol and an ester of phthalic acid and ethylene glycol as a repeating unit.

The mass of the ester derivative of monosaccharide was M1, the mass of the ester derivative of polysaccharide was M2, the mass of the ester oligomer was M3, and the sum of the masses obtained by M1+ M2+ M3 (hereinafter referred to as the sum of masses) was MP. When the CA film 11 contains at least one of an ester derivative of monosaccharide, an ester derivative of polysaccharide, and an ester oligomer, the sum MP of the masses is preferably in the range of 5 to 30, where the mass of the cellulose acylate is 100. When the mass and MP are 5 or more, the flexibility of the CA film 11 is good and/or the CA film 11 is easy to manufacture, as compared with the case of less than 5. When the mass sum MP is 30 or less, the water content of the CA film 11 is more preferable than that in the case of more than 30.

As the additive, the CA film 11 may contain (contain) an ultraviolet absorber, fine particles as a so-called matting agent for preventing the CA films 11 from sticking to each other, and the like, in addition to the plasticizer, as long as the above safety is confirmed. As a result of adjusting the moisture content of the CA film 11 by adjusting the type and amount of the additive, the humidity of the packaging bag 10 during storage of the vegetables and fruits is adjusted, and therefore, drying out of the vegetables and fruits can be suppressed in addition to condensation.

The propylene polymer (propylene resin) functions as a regulator of the water content and/or flexibility of the CA film 11. As the acrylic polymer, for example, methyl acrylate, methyl methacrylate, and a copolymer with these acrylic acid or methacrylic acid, and the like are preferable. When the CA film 11 contains an acrylic polymer, the mass of the acrylic polymer is preferably in the range of 10 to 300, assuming that the mass of the cellulose acylate is 100.

The safety of sugar esters, ester oligomers and acrylic polymers is described in the following documents. That is, The sugar esters include The society of Synthetic Organic Chemistry, Japan, Vol.21(1963) No.1, P-19-27 and DKS Co.Ltd. catalog, Japanese patent application laid-open No. 2011-237764, and The like. The product catalogue of dksco.ltd. describes fatty acid esters and benzoic acid esters of sugars. The ester oligomer is described in jp 2009-173740 a, which includes a mixture with cellulose triacetate as an additive to Vinyl chloride, in the netpage of Vinyl Environmental Council and KASOZAI INFORMATION data. Acrylic polymers are described in Japanese patent laid-open Nos. 2003-012859 and 2011-154360. The safety includes not only the safety of the above-mentioned substance itself but also the safety of a decomposition product of the above-mentioned substance.

The thickness of the CA film 11 is preferably in the range of 15 μm to 300 μm. As a result of adjusting the water content of the CA film 11 by adjusting the thickness, the humidity in the packaging bag 10 during storage of the vegetable and fruit is adjusted, and therefore condensation is suppressed and drying out of the vegetable and fruit is also suppressed. In addition, condensation is similarly suppressed when the composition is used for raising seedlings. And, by increasing the thickness, it is durable even in the form of a larger-sized package bag. The thickness of the CA film 11 is more preferably in the range of 20 μm to 200 μm, and still more preferably in the range of 30 μm to 120 μm.

The vegetables and fruits can maintain physiological functions such as water release and/or respiration. Therefore, when the packaging bag 10 is used for vegetables and fruits, condensation is remarkably suppressed, and the effect of suppressing the drying out of the contents is also remarkable. Examples of such fruits and vegetables include: cauliflowers such as broccoli and rape; green vegetables such as spinach and komatsuna; stem vegetables such as garlic and asparagus; fruit vegetables such as green pepper, eggplant, tomato, cucumber, strawberry, green soybean, etc.; fruits such as banana, grape, apple, pear, orange, etc.; rhizome of Chinese yam, burdock, etc.; mushrooms such as shiitake, agaricus blazei; and cut flowers of chrysanthemum, lily, etc. Among these, the packaging bag 10 can be preferably used in, for example, cauliflower, leaf vegetables, fruit vegetables, mushrooms, and cut flowers because of, for example, a particularly large amount of moisture released and a noticeable dew condensation during long-term storage and distribution in refrigeration. The above-described classification of vegetables and fruits is based on japanese standard product classification.

The CA film 11 prevents the packaging bag 10 from dewing or discoloring during normal-temperature storage of vegetables and fruits, and also prevents dewing or discoloring during refrigeration, thereby enabling long-term storage of vegetables and fruits. Dew condensation is suppressed, and thus mold and the like are also suppressed. The storage at room temperature means a range of 10 ℃ to 30 ℃ inclusive, and the storage at 0 ℃ to 10 ℃ inclusive is performed by cold storage.

The freshness of the vegetables and fruits is preferably kept by refrigeration. Since the CA film 11 absorbs and releases moisture according to the change in the humidity of the storage space due to the equilibrium moisture content of the CA film 11, dew condensation is prevented and the moisture content is further maintained at a humidity that suppresses drying out of the vegetables and fruits.

As shown in fig. 2, the porous film 12 is formed with a plurality of pores 15a, 15b, … …, 15g, 15h, … …. In the following description, the holes 15a, 15b, … …, 15g, 15h, and … … are simply referred to as holes 15, unless otherwise noted. The average pore diameter of the formed plurality of pores 15 is in the range of 0.0050 μm or more and 5.0 ℃ m or less. The average pore diameter is more preferably 0.0010 μm or more and 4.5 μm or less, and still more preferably 0.0020 μm or more and 2.0 μm or less. The average pore diameter can be determined based on the average pore diameter of a palm stomatological gauge manufactured by porouserierials corporation (usa), the nominal pore diameter shown in japanese industrial standard JIS K38021029 (pore diameter capable of removing 95% of particles using a uniform standard latex having a particle diameter as an example), and the like. In the present example, the average pore diameter is determined by the palm porosimeter. In the case of using a commercially available product as the porous film 12, the catalog value may be used.

The plurality of holes 15a to 15d are formed so as to penetrate in the thickness direction of the porous film 12 and communicate with each other in the thickness direction. The pores 15 having an average pore diameter within the above range are formed to penetrate in the thickness direction, and carbon dioxide and oxygen exchange gas through these pores 15. Therefore, in the interior of the packaging bag 10, for example, respiration of the vegetable or fruit is controlled or discoloration is suppressed by suppressing an excessive high concentration of carbon dioxide. In the case of using the film for growing seedlings, similarly, the gas acting on the respiration of the seedlings is exchanged with the gas through the porous film 12, and thus the seedlings grow well. The porous film in which the pores 15 having an average pore diameter within the above range are formed so as to penetrate in the thickness direction can be produced by, for example, a phase separation method. The porous film can also be produced by a method of thermally welding a nonwoven fabric such as polyethylene or polypropylene, or a method of forming communicating pores by subjecting a film material to chemical treatment, etching, or the like. Among these forming methods, the phase separation method can increase the volume ratio of the pores 15 in the thickness direction of the porous film. The phase separation method can maintain the strength of the porous film even if the volume ratio of the pores 15 in the thickness direction is further increased, and therefore, when pressure or the like is applied to the porous film, the pores 15 are less likely to collapse, and as a result, the gas exchange efficiency of carbon dioxide and oxygen passing through the pores 15 is increased, and therefore, the effects of storing vegetables and fruits and growing seedlings can be stably maintained.

In fig. 2, the holes 15e and 15f communicate with each other in a direction along the substantial film surface of the porous film 12, but when attention is paid to 5 holes 15a, 15b, 15e, 15f, 15g including these 2 holes 15e, 15f, the holes penetrate in the thickness direction. As described above, the plurality of holes 15 may be formed so as to pass through the package bag 10 from one of the outer film surface (hereinafter, referred to as the 1 st porous surface) 12A and the inner film surface (hereinafter, referred to as the 2 nd porous surface) 12B toward the other by communicating with each other, and all the communication directions of the holes 15 may not be the thickness direction. Further, among the plurality of holes 15 formed, there may be a hole which is not in communication with another hole 15, that is, which is partitioned into one space.

Since the average pore diameter of the plurality of pores 15 formed to penetrate in the thickness direction is 0.0050 μm or more, excessive changes in the concentration of each gas in the packaging bag 10 are reliably suppressed as compared with the case of being smaller than 0.0050 μm. Further, since the average pore diameter is 5.0 μm or less, the concentration of each gas is set in a range suitable for the storage of vegetables and fruits or the respiration of seedlings to be grown as compared with the case of being larger than 5.0 μm. Further, when the average pore diameter is in the range of 0.0050 μm or more and 5.0 μm or less, entry of viruses (having a size of approximately 0.03 μm or more and 0.1 μm or less), bacteria (having a size of approximately 0.2 μm or more and 5 μm or less), and/or fungi (including mold) (having a size of approximately 5 μm or more and 12 μm or less) can be suppressed. For example, the average pore diameter is 1.2. mu.m, the entry of fungi is suppressed, the average pore diameter is 0.20. mu.m, the entry of bacteria is suppressed, and the average pore diameter is 0.030. mu.m, the entry of viruses is suppressed. As a result, the stored vegetables and fruits can be preserved with good freshness, and when used for raising seedlings, the seedlings can be prevented from being damaged. Further, since the plurality of pores 15 having an average pore diameter within the above range are formed so as to communicate in the thickness direction, the entry of viruses, bacteria, and/or fungi is more reliably suppressed while ensuring controllability of the concentration of each gas as described above.

The material of the porous film 12 is not particularly limited as long as it is hydrophobic to such an extent that the pores 15 are not clogged by moisture released from the agricultural product. Examples of the inorganic filler include polysulfone, polyethersulfone, polyethylene, polypropylene, polyvinylidene fluoride, polytetrafluoroethylene, and cellulose acylate.

As the porous film 12, commercially available products distributed on the market may be used. For example, a filter having an average pore size of 0.030 μm attached to a cartridge of a microfilter made by fujifilm corporation Astropore (registered trademark) PSS03, a filter having an average pore size of 0.20 μm attached to a PSE cartridge, a filter having an average pore size of 1.2 μm attached to a PSE cartridge (the above filters are made of polysulfone), a filter having an average pore size of 0.45 μm attached to a FL cartridge (made of polytetrafluoroethylene), a filter having an average pore size of 4.5 μm attached to a PPE cartridge UXL (made of nonwoven fabric made of polypropylene), a filter having an average pore size of 0.65 μm attached to a viport (registered trademark) II cartridge made by Merck & Co Inc (made of polyvinylidene fluoride), and a filter having an average pore size of 0.20 μm attached to a cartridge made by Pall corporation.

The area ratio SR11 of the CA film 11 of the packaging bag 10 is preferably at least 10.0% because condensation can be more reliably suppressed. The area ratio SR11 is more preferably in the range of 10.0% to 99.9%, still more preferably in the range of 15.0% to 99.5%, and particularly preferably in the range of 25.0% to 99.2%.

The area ratio SR12 of the porous film 12 in the packaging bag 10 is preferably in the range of 0.1% to 20.0%, from the viewpoint of controlling the concentration of each gas in the storage space. The area ratio SR12 is more preferably in the range of 0.3% to 15.0%, and particularly preferably in the range of 0.5% to 10.0%.

The area ratio SR11 and the area ratio SR12 are obtained by the following methods. In the packaging bag 10, the total surface area of the partition wall partitioning the inside of the containing space for containing vegetables and fruits from the outside space is SA, the area of the CA film 11 in the partition wall is S11, and the area of the porous film 12 is S12, as shown in fig. 3. Since the joint portion 10a (see fig. 1) does not function as a partition wall partitioning the housing space and the external space, the area of the joint portion 10a is not included in any of the areas S11 and S12. Therefore, in fig. 3, the areas of the joint portion 10a indicated by the two-dot chain line are not hatched, indicating the areas of the symbols S11 and S12. In this example, as described above, there is an overlapping region where the CA film 11 overlaps the outer peripheral portion of the porous film 12. In this way, when there is an overlapping region between the two regions, the overlapping region is omitted and the regions are set to the area S11 and the area S12. That is, the area of only the portion of the CA film 11 is S11, and the area of only the portion of the porous film 12 is S12. In fig. 3, the overlapping region of the CA film 11 and the porous film 12 is not drawn, as in fig. 1. The total surface area SA, the area S11, and the area S12 are the surface area of the inner surface, which is the surface area on the inner side (the accommodating space side) of the packaging bag 10. The area ratio SR11 (unit is%) was determined by (S11/SA). times.100. The area ratio SR12 (unit is%) was determined by (S12/SA). times.100. In addition, since the partition walls of the packaging bag 10 in this example are composed of only the CA film 11 and the porous film 12, the total surface area SA is the sum of the areas S11 and S12 (S11+ S12).

The packaging bag may be provided with other films in addition to the CA film 11 and the porous film 12. The packaging bag 30 shown in fig. 4 is entirely made of a film, as in the packaging bag 10, and includes a CA film 11, a porous film 12, and a polypropylene film (hereinafter, referred to as a PP film) 31. The PP film 31 is an example of a film different from either the CA film 11 or the porous film 12, and is formed of polypropylene. In the PP film 31, the pores 15 as in the porous film 12 are not formed. The 1 st sheet is composed of a CA film 11, a porous film 12 and a PP film 31, and the 2 nd sheet is composed of a PP film 31. In fig. 4, the sheet on the near side is drawn as a 1 st sheet and the sheet on the far side is drawn as a 2 nd sheet, as in fig. 1. At least one of the 1 st sheet and the 2 nd sheet may further include a film different from the PP film 31. The 2 nd sheet may include at least one of the CA film 11 and the porous film 12. In fig. 4, the same components as those in fig. 1 are denoted by the same reference numerals as those in fig. 1, and descriptions thereof are omitted.

In the 1 st sheet, the CA film 11 constitutes the upper region in fig. 3, and the porous film 12 and the PP film 31 constitute the lower region, but the region constituted by each of the CA film 11, the porous film 12, and the PP film 31 and the positional relationship therebetween are not limited to this example. The porous film 12 is disposed in a state of being surrounded by the PP film 31, but the positional relationship between the porous film 12 and the PP film 31 is not limited to this, and for example, the PP film 31 and the porous film 12 may be disposed in a state of being divided into regions in any one of the left-right, up-down, or oblique directions in fig. 3. The porous film 12 is disposed in a state of being surrounded by the PP film 31, but is not limited to this embodiment. For example, the CA film 11 may be arranged so as to be surrounded by the upper CA film in fig. 4. In this example, 2 sheets of the porous film 12 are arranged, but 3 sheets or more may be used, or 1 sheet may be used as in the packaging bag 10. In this manner, the number of the porous film 12 is not particularly limited.

The PP film 31 is used as a film made of a hydrophobic material to such an extent that it is not deformed by moisture released from agricultural products, and may be another film as long as it is made of such a material having hydrophobicity. For example, a polyethylene film made of polyethylene, a polyethylene terephthalate film made of polyethylene terephthalate, or the like can be used.

The CA film 11 and the PP film 31 and the porous film 12 and the PP film 31 in the 1 st sheet are joined to each other with an overlapping area, but the overlapping area is extremely small in width, and therefore, illustration thereof is omitted in fig. 4. The bonding of the CA film 11 and the PP film 31 and the bonding of the porous film 12 and the PP film 31 can be performed by, for example, heat sealing.

In the packaging bag 30, the preferable ranges of the area ratio of the CA film 11 and the area ratio of the porous film 12 are the same as those in the packaging bag 10. As shown in fig. 5, the area of the PP film 31 in the partition wall partitioning the housing space and the external space is S31. The area S31 is indicated by cross hatching in fig. 5, and the area S31 is also the surface area on the accommodating space side, as with the total surface area SA, the area S11, and the area S12. The total surface area SA in this example is S11+ S12+ S31, which are used in the above calculation formulas for the area ratio SR11 and the area ratio SR12, respectively. In the case where a film other than the CA film 11 and the porous film 12 is used in this manner, the area of the film may be included in the total surface area SA. The packaging bag 30 is not limited to packaging agricultural products, and can be used for agricultural production, as with the packaging bag 10.

The agricultural container is not limited to a bag shape, and may be, for example, a box shape. The agricultural container may be provided with a member other than the film. The packing box 50, which is an example of the agricultural container shown in fig. 6, contains agricultural products in the same manner as the packing bags 10 and 30. In this example, although vegetables and fruits are contained as agricultural products, the vegetables and fruits are not shown in fig. 6. In fig. 6, the same components as those in fig. 1 are denoted by the same reference numerals as those in fig. 1, and descriptions thereof are omitted.

As shown in fig. 6, the package case 50 includes a housing member 51 formed in a box shape with an open upper portion, a CA film 11 disposed on a top surface, and a porous film 12 provided in the housing member 51. In fig. 6, the thickness of the CA film 11 is exaggerated relative to the thickness of the housing member 51. The housing member 51 includes a bottom plate 52 as a bottom surface portion and 4 side plates 53a to 53d as side surface portions provided in a standing posture with respect to the bottom plate 52. In the case where the side plates 53a to 53d are not distinguished, they are hereinafter referred to as side plates 53. The housing member 51 is formed of polypropylene, but the material of the housing member 51 is not particularly limited as long as it is hydrophobic to such an extent that it is not deformed by moisture released from the agricultural product. As the material other than polypropylene, for example, polyethylene terephthalate, polystyrene, or the like can be used.

The shape of the bottom plate 52 is set to be rectangular, but is not limited to rectangular. The bottom plate 52 may be rectangular other than rectangular, for example, square, or may be circular (perfect circle or ellipse), and the shape is not particularly limited. A plurality of openings 56 are formed in each of the side plates 53a and 53c arranged in an opposing posture among the side plates 53a to 53d, and the porous film 12 is provided in the side plates 53a and 53c in a state of covering the plurality of openings 56. Thus, the porous film 12 functions as a partition wall for partitioning the storage space for storing the vegetables and fruits from the external space in the opening 56. In this way, in the package case 50, a part of the partition wall partitioning the storage space and the external space is formed of a film, and it is not necessary to form the entire partition wall by a film as in the package bags 10 and 30. That is, at least a part of the packaging container may be formed of a film.

The openings 56 are formed in the side plate 53a and the side plate 53c, respectively, but any one of the side plate 53a and the side plate 53c may be used. However, in order to make the gas exchange in the storage space of the package box 50 more effective, it is more preferable to form two side plates 53a and 53c facing each other. In addition, the opening 56 may be formed in the side plate 53b and the side plate 53d instead of the side plate 53a and the side plate 53c, and may be formed in at least 3 side plates 53 out of all the side plates 53a to 53 d.

The position of the opening 56 is located further upward in the vertical direction in fig. 6, but the present invention is not limited to this, and may be located further downward or at the center in the vertical direction in fig. 6. In this example, the plurality of openings 56 are formed so as to be aligned in the depth direction, but may be formed so as to be aligned in the vertical direction, or may be irregularly arranged.

In this example, the porous film 12 is provided on the surface (outer surface) of each of the side plates 53a and 53c on the external space side, but may be provided on the surface on the accommodation space side. The opening 56 is formed in a circular shape having a diameter of, for example, 8mm, but the shape is not particularly limited to a polygonal shape, an irregular shape, a slit shape, or the like, as long as it is larger than the pores 15 of the porous film 12 so as not to damage the above-described respective functions of the porous film 12. The number of the openings 56 in each of the side plates 53a and 53c is drawn as 4 in fig. 6, but is not particularly limited, and may be 1 to 3, or 5 or more.

The CA film 11 is provided on the upper portion of the housing member 51 as the top surface portion of the package box 50, but the CA film 11 may be provided as a side surface portion instead of a part of the housing member 51. For example, the CA film 11 may be provided on the side plate 53 in a state of covering the opening 56, and in this case, the porous film 12 may be provided as a part of the top surface portion. As described above, the CA film 11 and the porous film 12 may be at any position in the package case 50 as long as they function as partitions for partitioning the storage space from the external space. Therefore, a part of the CA film 11 on the top surface portion may be replaced with the porous film 12.

In the packaging case 50, the preferable ranges of the area ratio of the CA film 11 and the area ratio of the porous film 12 are the same as those in the case of the packaging bag 10. As shown in fig. 7, the area of the accommodating member 51 in the partition wall partitioning the accommodating space and the external space is S51. The area S51 is indicated by cross hatching in fig. 7, and the area S51 is also the surface area on the accommodating space side, as with the total surface area SA, the area S11, the area S12, and the area S31. The total surface area SA in this example is S11+ S12+ S51, which are used in the above calculation formulas for the area ratio SR11 and the area ratio SR12, respectively. In this manner, when a film and/or member other than the CA film 11 and the porous film 12 is used, the area of the film and/or member may be included in the total surface area SA. In addition, since the total surface area SA, the area S11, and the area S12 are also the surface area on the side of the storage space, that is, the area of the inner surface in this example, fig. 7 is a view showing the inner surface side.

The packaging case 50 is not limited to packaging agricultural products, and can be used for agricultural production, as with the packaging bags 10 and 30. For example, it can be used in a nursery box for growing seedlings, and in this case, it is preferable to consider the post-growth size of the seedlings so as to be able to accommodate the grown seedlings. The seedling raising device 69 shown in fig. 8 includes a seedling raising box 70 as an agricultural container and a light source unit 71.

The seedling raising box 70 is formed larger than the packing box 50, and the position and number of the openings 56 and the size of the porous film 12 are different from those of the packing box 50, but the other structure is the same as that of the packing box 50. The same structure and operation as those of the packing case 50 will not be described. In fig. 8, illustration of the side plate 53d (see fig. 6) on the near side of the sheet is omitted. The material to be received is the seedbed 74 and the seedling 75 to be grown, and the seedling 75 is a seedling smaller than the cut seedling, more specifically, a height of 1cm or more and 8cm or less and/or a number of leaves of 2 or more and 5 or less. The seedling 75 is an example of a seedling, and therefore, the seedling 75 may be replaced by a seed (not shown), and in the case of a seed, the seedling raising device 69 performs germination and growth (seedling raising) of a seedling.

The seedling 75 in this example is a seedling of komatsuna, but the seedling is not limited to komatsuna, and may be a seedling of leaf vegetables or fruit vegetables other than komatsuna. Examples of the fruit vegetables include eggplant, green pepper, hot pepper, cucumber, green soybean, corn, tomato, strawberry, and the like. Examples of the other seedlings of the leafy vegetables include seedlings of cabbage, lettuce, broccoli, celery, spinach, and perilla.

The number of seedlings 75 is set to a plurality in this example, but is not limited to a plurality, and may be 1. Further, although the plurality of seedlings 75 are planted on the different beds 74, the number of seedlings 75 planted on one bed 74 is not particularly limited. The seedbeds 74 are arranged in a square shape in the horizontal direction, and the number of rows (the number in the left-right direction in fig. 8) is 5 rows in this example, but the present invention is not limited to this example, and may be in the range of 1 row or more and 4 rows or less, or 6 rows or more. In the figure, an arrow X is given to the column direction, an arrow Y is given to the row direction orthogonal to the column direction X in the horizontal direction, and an arrow Z is given to the vertical direction. In the present embodiment, the number of rows (the number in the row direction Y) of the bed 74 is, for example, 1 row, 2 rows, or 10 rows. The number of rows of the seedbed 74 is not limited to this example, and may be in the range of 3 rows or more and 9 rows or less, or 11 rows or more.

The arrangement of the plurality of seedbeds 74 in the horizontal direction is not limited to the square arrangement, and may be a regular arrangement other than the square arrangement or an irregular (random) arrangement. In this example, the plurality of seedbeds 74 are arranged with a small gap therebetween, but the seedbeds 74 may be arranged in contact with each other.

In this example, the container 76 is further stored as the content. The upper part of the container 76 is opened, and water 77 and the bed 74 are put in. Thereby, at least the lower part of the seedbed 74 is immersed in the water 77. By this impregnation, the seedling 75 is supplied with water. The bed 74 may be any known material, such as soil, sponge, or fiber material. In the present embodiment, Rockwool is used as the seedbed 74, specifically, a gridan (registered trademark) Rockwool cube manufactured by Nippon Rockwool Corporation (Rockwool b.v. the netherlands). The seedling raising device 69 is a device for growing the seedlings 75 by hydroponic cultivation, but the cultivation method by the seedling production device is not limited to hydroponic cultivation. Examples of the other cultivation method include soil cultivation, nutrient solution cultivation, and overhead cultivation, and the seedbed 74 may be changed to a seedbed corresponding to the cultivation method.

The light source unit 71 is used to irradiate light to the seedbed 74 and/or the seedling 75. Before germination in the case of germinating the seeds, the light source unit 71 is used to irradiate the seedbed 74 with light. The light source unit 71 includes a plurality of light sources 81 for emitting light, a support plate 82, and a controller 83, and the light sources 81 and the support plate 82 are disposed above the seedling box 70. The support plate 82 is an example of a support member that supports the plurality of light sources 81, and in this example, the light sources 81 are provided on a lower surface that is an opposing surface opposing the seedling raising box 70. The controller 83 has a 1 st function of adjusting the amount of light emitted from each of the plurality of light sources 81 and a 2 nd function of performing on-off control of each of the plurality of light sources 81. The irradiation amount of light to the seedling 75 or the bed 74 is adjusted by the 1 st function. The timing and time of light irradiation are adjusted according to the type and/or growth degree of the seedling 75 by the function 2. In this manner, the light source 81 irradiates the seedling 75 or the bed 74 with light controlled by the controller 83. Thereby, the seedling 75 grows, and in the case of seeds, germination proceeds. In this example, the distance from the light source 81 to the seedling raising box 70 is set to approximately 100mm, but the present invention is not limited to this example.

The seedling box 70 has a temperature and humidity controller 86. The temperature and humidity controller 86 adjusts the temperature and humidity inside the seedling box 70 to control the growth environment of the seedlings 75. The temperature inside the seedling box 70 is not particularly limited, but is preferably within a range of 10.0 ℃ to 40.0 ℃. In this example, the temperature was set to 20.0 ℃ to confirm that the temperature varied within a range of 17.5 ℃ to 22.5 ℃. The humidity inside the seedling raising box 70 is not particularly limited, but is preferably a relative humidity within a range of 50.0% to 80.0%. In this example, the content is in the range of 40.5% to 91.0%.

The CA film 11 disposed on the top surface of the seedling box 70 is transparent because it is made of cellulose acylate. Therefore, the light from the light source 81 disposed above the seedling raising box 70 is effectively irradiated on the seedling 75 and/or the bed 74, and the growth of the seedling is further promoted. In this manner, the light source 81 and the CA film 11 are preferably arranged in a positional relationship in which they face each other.

The seedling raising box 70 is set to a height capable of accommodating the grown seedlings 75 in consideration of the height of the grown seedlings 75. The opening 56 is formed in the center of the side plate 53a and the side plate 53c in the vertical direction Z. Since the porous film 12 is provided on the side plate 53 forming the side surface of the seedling raising box 70, the porous film 12 is also provided in a standing posture with respect to the bed 74. Thus, the space above the bed 74 in the accommodating space of the seedling box 70 is more reliably exchanged with gas through the porous film 12, and as a result, the respiration of the seedling 75 is more reliably controlled.

Examples of the present invention and comparative examples to the present invention are given below.