Freshness-keeping packaging member, and freshness-keeping method of garden stuff

Abstract

To provide: a freshness-keeping packaging member exhibiting an excellent garden stuff deterioration preventing property; and a freshness-keeping method of garden stuff using the freshness-keeping packaging member.SOLUTION: A freshness-keeping packaging member or the like comprises: a film; span-bond nonwoven fabric; and a resin layer for covering at least a part of a fiber face forming nonwoven fabric onto a face on a side where the span-bond nonwoven fabric comes into contact with at least the film, in this order. Total light transmittance in a wavelength range between 320 nm and 780 nm according to a spectral spectrum has a mean value of 1.00% or less. Water-vapor permeability at 5°C is 200 g / m2 24hr to 1200 g / m2 24hr. A hue in CIE 1976 (La*b*) color space on at least one face has a brightness L of 40 or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a freshness-preserving packaging member and a method for preserving the freshness of fruits and vegetables. [Background technology]

[0002] Freshness-maintaining packaging materials are widely used, for example, for the purpose of protecting fruits and vegetables from fluctuations in the external environment during storage or transportation of the fruits and vegetables and maintaining a good state of freshness when packaged. As a freshness-preserving packaging material for fruits and vegetables, for example, a specific polymer resin is used, and the water vapor permeability is 20 g / m 2 A freshness-preserving package for fruits and vegetables has been proposed, which is a bag-shaped package that can be stored for 24 hours at 40°C and 90% RH or higher, in which the carbon dioxide and oxygen concentrations within the package are controlled and the weight loss rate of the entire package is less than 1 wt% (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-146291 Summary of the Invention [Problem to be solved by the invention]

[0004] The freshness-preserving packaging for fruits and vegetables described in Patent Document 1 is formed from a porous resin film sheet, and is said to be able to maintain the humidity, oxygen concentration, etc. inside the packaging at an appropriate level for the fruits and vegetables by controlling the permeation of water vapor, carbon dioxide, oxygen, etc. However, because the porous resin film sheet is a non-hygroscopic material, if the moisture permeability of the film sheet is insufficient, problems such as water droplets forming inside the packaging and discoloration of the contents may occur. Furthermore, when fresh produce such as broccoli and rapeseed flowers is stored, progress in the light response can cause yellowing due to flowering, undesired germination, and other problems, and improvements are needed.

[0005] An object of one embodiment of the present disclosure is to provide a freshness-maintaining packaging member that effectively prevents deterioration of fruits and vegetables. The problem to be solved by another embodiment of the present disclosure is to provide a method for preserving the freshness of fruits and vegetables that can prevent deterioration of the fruits and vegetables using the freshness-preserving packaging member of the present disclosure. [Means for solving the problem]

[0006] The means for solving the above problems include the following aspects.

[0007] <1> The nonwoven fabric has, in this order, a film, a spunbonded nonwoven fabric, and a resin layer on at least the surface of the spunbonded nonwoven fabric that comes into contact with the film, the resin layer covering at least a part of the surface of the fibers that form the nonwoven fabric; The average value of the total light transmittance in the wavelength range of 320 nm to 780 nm in the spectroscopic spectrum is 1.00% or less, Moisture permeability at 5℃ is 200g / m 2 24hr~1200g / m 2 24hrs A freshness-preserving packaging material, at least one surface of which has a hue lightness L of 40 or less in the CIE1976 (La*b*) color space.

[0008] <2> The film is a perforated film. <1> The freshness-preserving packaging member according to claim 1. <3> The perforated film comprises a thermoplastic resin and a filler. <2> The freshness-preserving packaging member according to claim 1. <4> The fibers forming the spunbonded nonwoven fabric are made of one or more resins selected from the group consisting of polyethylene, polypropylene, and polyethylene terephthalate. <1> ~ <3> The freshness-preserving laminate according to any one of <5> The thermoplastic resin comprises one or more resins selected from the group consisting of polyethylene, polypropylene, and polyethylene terephthalate. <3> or <4> The freshness-preserving packaging member according to claim 1.

[0009] <6> The thickness of the film is in the range of 50 μm to 1 mm. <1> ~ <5> 10. The freshness-preserving packaging member according to claim 9, wherein the packaging material is a <7> It is formed into a bag shape and is used to put inclusions inside. The brightness L of one surface is 40 or less, and the brightness L of the other surface is 70 to 100, The surface having a lightness L of 40 or less is the surface on the inclusion side. <1> ~ <6> 10. The freshness-preserving packaging member according to claim 9, wherein the packaging material is a

[0010] <8> <1> ~ <7> a package fabrication process for fabricating a package by forming the freshness-preserving packaging member according to any one of the above into a bag shape and placing fruits and vegetables inside the bag-shaped freshness-preserving packaging member; and adjusting the average humidity inside the obtained package to 95% to 99%. <9> The adjusting step is carried out at a temperature of 20°C or less. <8> The method for preserving the freshness of fruits and vegetables described in the above. [Effects of the Invention]

[0011] According to one embodiment of the present disclosure, a freshness-preserving packaging member that effectively prevents deterioration of fruits and vegetables is provided. According to another embodiment of the present disclosure, there is provided a method for preserving the freshness of fruits and vegetables, which can prevent deterioration of fruits and vegetables using the freshness-preserving packaging member of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0012]

[0023] The following describes embodiments of the present disclosure. These descriptions and examples are intended to illustrate the embodiments and are not intended to limit the scope of the embodiments. In the present disclosure, a numerical range indicated using "to" indicates a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In the numerical ranges described in stages in this disclosure, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. In the numerical ranges described in this disclosure, the upper or lower limit value of the numerical range may be replaced with the value shown in the examples. In the present disclosure, each component may contain multiple types of corresponding substances. In the present disclosure, when referring to the amount of each component in a composition, if multiple substances corresponding to each component are present in the composition, the total amount of the multiple substances present in the composition is meant unless otherwise specified. In the present disclosure, the term "step" includes not only an independent step, but also a step that cannot be clearly distinguished from other steps as long as the purpose of the step is achieved.

[0013] [Freshness-preserving packaging materials] The freshness-preserving packaging member of the present disclosure comprises, in this order, a film, a spunbond nonwoven fabric, and a resin layer that covers at least a portion of the fiber surface of the nonwoven fabric on at least the surface of the spunbond nonwoven fabric that comes into contact with the film, and the freshness-preserving packaging member has an average total light transmittance of 1.00% or less in a wavelength range of 320 nm to 780 nm in a spectroscopic spectrum, and a moisture permeability of 200 g / m at 5°C. 2 24hr~1200g / m 2 24hr, and the hue lightness L in the CIE1976 (La*b*) color space of at least one side is 40 or less. The freshness-preserving packaging member of the present disclosure (hereinafter also referred to as the packaging member of the present disclosure) is used for preserving and transporting vegetables, fruits, etc., and is particularly suitable for preserving and packaging fruits and vegetables.

[0014] The packaging member of the present disclosure comprises, in this order, a film, a nonwoven fabric, and a resin layer that covers at least a portion of the fiber surface forming the nonwoven fabric on at least the side of the spunbond nonwoven fabric that comes into contact with the film, and is therefore believed to have excellent strength, flexibility, and moisture permeability, making it ideal for protecting the fruits and vegetables contained therein.Furthermore, in addition to providing light-blocking properties through control of total light transmittance, by setting the brightness of at least one side to 40 or less, it is believed to effectively suppress deterioration of the fruits and vegetables due to the progression of their photoresponse. Therefore, the packaging member of the present disclosure is suitable for use with fruits and vegetables in general, and is particularly useful for preserving the freshness of broccoli, rape blossoms, spinach, and the like, which are susceptible to deterioration due to photoresponse.

[0015] (film) The packaging member of the present disclosure has a film. From the viewpoint of maintaining the moisture permeability of the packaging member of the present disclosure within the range described below, the film is preferably a resin film having a certain degree of moisture permeability or a porous film.

[0016] As the film material, single-layer, multi-layer, colored or uncolored films made of thermoplastic synthetic resins that are commonly used for packaging materials, such as polyethylene resins, polypropylene resins, and polyvinyl chloride resins, can be used. The film in the freshness-preserving packaging member of the present disclosure is preferably a perforated film. By using a perforated film as the film, water vapor generated from the fruits and vegetables can pass through, preventing stuffiness and making it easier to maintain the moisture permeability of the inside of the packaging material within an appropriate range. A perforated film is a moisture-permeable film that has a plurality of pores inside the film. Examples of perforated films include films perforated by mechanical means such as a laser, and porous films containing a thermoplastic resin and a filler, which will be described later.

[0017] The perforated film preferably comprises a thermoplastic resin and a filler. A perforated film can be formed by stretching a film containing a thermoplastic resin and a filler to generate voids between the filler and the thermoplastic resin.

[0018] The type of thermoplastic resin used for the perforated film is not particularly limited. Examples of thermoplastic resins include polyolefin resins such as polyethylene resins, propylene resins, polymethylpentene, and ethylene-cyclic olefin copolymers; polyamide resins such as nylon-6, nylon-6,6, nylon-6,10, and nylon-6,12; thermoplastic polyester resins such as polyethylene terephthalate and copolymers obtained by adding a copolymerizable component to the same monomer, polyethylene naphthalate, polylactic acid, and aliphatic polyester; and thermoplastic resins such as polycarbonate, atactic polystyrene, syndiotactic polystyrene, and polyphenylene sulfide. These thermoplastic resins may be used alone or in combination of two or more. Among these, from the viewpoints of water resistance, production costs, etc., it is preferable that the thermoplastic resin contains one or more resins selected from the group consisting of polyethylene, polypropylene, and polyethylene terephthalate. As the polyethylene-based resin, ethylene-based resins such as high-density polyethylene, medium-density polyethylene, low-density polyethylene, ethylene-α-olefin copolymer, and compositions thereof can be used. Melt flow rate (MFR) of thermoplastic resin ( MFR 190 (ASTM D 1238, 190°C, load 2160 g) is preferably 0.01 to 20, and more preferably 0.1 to 10 g / 10 min from the viewpoint of film uniformity. Here, the MFR of the polyethylene resin is 190 MFR230: Measured according to ASTM D-1238 at 190°C and a load of 2160g, and the MFR of propylene-based resin is measured according to ASTM D-1238 at 230°C and a load of 2160g.

[0019] The content of the thermoplastic resin in the film is preferably 25% by mass to 80% by mass, more preferably 30% by mass to 70% by mass, based on the total amount of the film. If the content of the thermoplastic resin in the film is 25% by mass or more, scratches tend to be less likely to occur on the surface during stretch molding of the stretched thermoplastic resin film described below. If the content of the thermoplastic resin in the film is 80% by mass or less, a sufficient number of pores tends to be easily obtained.

[0020] Fillers that can be used in the apertured films according to the present disclosure include various inorganic and organic fillers. Examples of inorganic fillers include heavy calcium carbonate, precipitated calcium carbonate, calcined clay, talc, titanium oxide, barium sulfate, aluminum sulfate, silica, zinc oxide, magnesium oxide, and diatomaceous earth. The organic filler used has a melting point or glass transition point (for example, 120°C to 300°C) higher than the melting point or glass transition point of the thermoplastic resin used. For example, if the thermoplastic resin is a polyolefin resin, examples of the organic filler include polyethylene terephthalate, polybutylene terephthalate, polyamide, polycarbonate, polyethylene naphthalate, polystyrene, melamine resin, cyclic olefin homopolymer, ethylene-cyclic olefin copolymer, polyethylene sulfide, polyimide, polyether ether ketone, and polyphenylene sulfide. Among these, it is preferable to use an organic filler that is incompatible with the thermoplastic resin used in terms of pore formation. These fillers may be used alone or in combination of two or more types. When two or more types are used in combination, an inorganic filler and an organic filler may be mixed and used.

[0021] Among these, from the viewpoint of good pore-forming properties and the appearance of the resulting film, at least one selected from metal oxides such as titanium oxide, and metal carbonates such as calcium carbonate and sodium carbonate is preferred, and calcium carbonate is more preferred.

[0022] In order to adjust the size of pores generated in the film by stretching the film as described below, the average particle size of the inorganic filler or the average dispersed particle size of the organic filler can be preferably in the range of 0.05 μm to 2.0 μm, more preferably in the range of 0.1 μm to 1.5 μm. Using a filler with an average particle size or average dispersed particle size of 0.05 μm or more tends to make it easier to obtain desired pores. Using a filler with an average particle size or average dispersed particle size of 2.0 μm or less tends to make the pore size of the porous film more uniform.

[0023] The porosity of the porous film in the present disclosure is preferably 25% to 60%, which makes it easier to control the total light transmittance and moisture permeability (described below) within preferred ranges.

[0024] From the viewpoint of adjusting the pore volume of the porous film, the amount of the filler blended in the film is preferably 20% to 60% by mass, more preferably 21% to 50% by mass, and even more preferably 22% to 40% by mass. If the filler content in the porous film is 20% by mass or more, a sufficient number of pores tends to be obtained, and if the filler content is 75% by mass or less, the occurrence of scratches on the surface tends to be further suppressed.

[0025] The film used in the packaging member of the present disclosure may contain, as necessary, a dye, a fluorescent brightener, a heat stabilizer, a UV absorber, a light stabilizer such as a UV stabilizer, a dispersant, a lubricant, etc. Examples of heat stabilizers include sterically hindered phenolic, phosphorus-based, and amine-based stabilizers. The content of the heat stabilizer may be 0.001% by mass to 1% by mass relative to the total amount of the film. Examples of light stabilizers include sterically hindered amines, benzotriazole-based, and benzophenone-based light stabilizers. The content of the light stabilizer may be 0.001% by mass to 1% by mass relative to the total amount of the film. Examples of dispersants include silane coupling agents, higher fatty acids (e.g., oleic acid, stearic acid, etc.), metal soaps, polyacrylic acid, polymethacrylic acid, and salts thereof. The content of the dispersant may be 0.01% by mass to 4% by mass relative to the total amount of the film.

[0026] The content of the ultraviolet absorber, ultraviolet stabilizer, and antioxidant that can be contained in the film is preferably 0.1 to 15% by mass, more preferably 0.5 to 10% by mass, relative to the total amount of the film.

[0027] The basis weight of the film is not particularly limited and is adjusted appropriately depending on the application. From the viewpoint of obtaining a covering sheet that has a good balance between rigidity and flexibility, the basis weight of the film is preferably 15 g / m 2 ~60g / m 2 , more preferably 30 g / m 2 ~50g / m 2 The method for measuring the basis weight of the film is the same as that described in the examples.

[0028] The thickness of the film is not particularly limited and is adjusted appropriately depending on the application. From the viewpoint of obtaining a protective member that has a good balance between durability and flexibility, the thickness of the film is preferably 50 μm to 1 mm, and more preferably 50 μm to 500 μm. The method for measuring the thickness of the film in the present disclosure is the same as that described in the Examples.

[0029] The film may be a commercially available product, or may be a film obtained by molding a resin. The method for forming the resin into a film is not particularly limited, and any general method for forming a film can be applied. Film molding methods that can be used include a combination of standard extrusion molding with uniaxial or biaxial stretching. Specific examples of stretch molding include a method in which molten resin is extruded into a sheet using a single- or multi-layer T-die or I-die connected to a screw extruder, followed by uniaxial stretching using longitudinal stretching that utilizes the difference in peripheral speed between a group of rolls; a sequential biaxial stretching method in which this is then combined with transverse stretching using a tenter oven; a simultaneous biaxial stretching method in which a tenter oven is combined with a linear motor; and an inflation molding method in which molten resin is extruded into a cylindrical shape using a single- or multi-layer O-die connected to a screw extruder, followed by air blowing. The stretching temperature is 2°C to 60°C lower than the melting point of the thermoplastic resin used and 2°C to 60°C higher than the glass transition point, and is preferably 95°C to 165°C when the resin is a propylene homopolymer (melting point 155°C to 167°C) and 100°C to 130°C when the resin is polyethylene terephthalate (glass transition point: approximately 70°C). The stretching speed is preferably 20 m / min to 350 m / min. In order to adjust the amount and size of pores formed in the perforated film, the stretching ratio of the breathable film is preferably in the range of 3 to 8, which makes it easier to obtain sufficient fine pores. Here, the stretching ratio refers to the longitudinal stretching ratio of the film.

[0030] (spunbond nonwoven fabric) The packaging member of the present disclosure comprises a spunbond nonwoven fabric. By including a spunbond nonwoven fabric in the packaging member of the present disclosure, the tear strength and tensile elongation are improved compared to when the packaging member does not include a spunbond nonwoven fabric. The spunbond nonwoven fabric is not particularly limited as long as it has the necessary mechanical strength, and among these, the spunbond nonwoven fabric is preferably a nonwoven fabric comprising at least one thermoplastic composition. The fibers forming the spunbonded nonwoven fabric are preferably made of one or more resins selected from the group consisting of polyethylene, polypropylene, and polyethylene terephthalate. Examples of thermoplastic resins include polyethylene resins, polypropylene resins, and polyvinyl chloride resins. Among these, resins selected from polypropylene resins and polyester resins are preferred. Furthermore, from the viewpoint of improving strength, it is also preferred that the thermoplastic resin contains polyethylene terephthalate fibers in addition to a resin selected from polypropylene resins and polyester resins. The constituent fibers may be monocomponent or multicomponent fibers, and the cross-sectional shape of the constituent fibers is not particularly limited and may be round, flat, hollow, etc. The spunbond nonwoven fabric may be single-layered, multi-layered, colored, or uncolored.

[0031] The propylene-based resin (hereinafter also referred to as "propylene-based polymer (A)") used in the spunbonded nonwoven fabric is preferably a propylene homopolymer or a copolymer of propylene and a small amount of one or more α-olefins having 2 or more carbon atoms (excluding 3 carbon atoms), preferably 2 to 8 carbon atoms (excluding 3 carbon atoms), such as ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene, or 4-methyl-1-pentene, each of which has a melting point (Tm) of 125°C or higher, preferably in the range of 130 to 165°C.

[0032] The melt flow rate (MFR230: ASTM D-1238, 230°C, load 2160 g) of the propylene polymer (A) is not particularly limited as long as it can be melt-spun, and can be, for example, in the range of 1 g / 10 min to 500 g / 10 min, preferably 5 g / 10 min to 200 g / 10 min, and more preferably 10 g / 10 min to 100 g / 10 min.

[0033] The ratio (Mw / Mn) of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn) of the propylene polymer (A) is usually 1.5 to 5.0. The ratio (Mw / Mn) is preferably in the range of 1.5 to 4.5, since fibers having good spinnability and particularly excellent fiber strength can be obtained. Mw and Mn can be measured by a known method such as GPC (gel permeation chromatography). From the viewpoints of the strength of the resulting spunbonded nonwoven fabric (such as the bonding strength of the heat-embossed portion) and the strength and durability of the covering sheet, it is preferable that the values ​​are within the above ranges.

[0034] Ethylene-based polymers (hereinafter also referred to as "ethylene-based polymers (B)"), which are other components of the propylene-based polymer composition that is the raw material for spunbond nonwoven fabrics, are polymers mainly composed of ethylene, such as high-pressure low-density polyethylene, linear low-density polyethylene (so-called LLDPE), medium-density polyethylene (so-called MDPE), and high-density polyethylene (so-called HDPE), which are ethylene homopolymers or copolymers of ethylene with small amounts of α-olefins such as propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene.

[0035] The ethylene polymer (B) has a density of 0.94 to 0.97 g / cm3 from the viewpoint of spinnability and strength of the fiber. 3 , and even 0.95 to 0.97 g / cm 3 High density polyethylene (HDPE) in the range of

[0036] The ethylene polymer (B) should have a melt flow rate (MFR) as high as possible for it to be added to the propylene polymer (A) and be melt-spun. 190 The melt flow rate (ASTM D 1238, 190°C, load 2160g) is not particularly limited, but can usually be in the range of 0.10g / 10 minutes to 100g / 10 minutes, more preferably 0.50g / 10 minutes to 50g / 10 minutes, even more preferably 10g / 10 minutes to 30g / 10 minutes, and particularly preferably 20g / 10 minutes to 10g / 10 minutes. When the melt flow rate of the ethylene polymer is in the above range, the resulting spunbond nonwoven fabric will have excellent strength.

[0037] The polyester resin may be a homopolymer selected from the group consisting of polyethylene terephthalate, polytrimethylene terephthalate, and polybutylene terephthalate, or a copolymer or blend in which one of these groups is present in some of the repeating units. The polyester resin film and polyester resin nonwoven fabric are preferred from the viewpoint of enhancing the adhesiveness between the two layers. Adhesion can be further improved by performing corona treatment, if necessary.

[0038] The propylene-based composition or polyester-based resin composition used for the spunbonded nonwoven fabric may contain various known additives such as colorants, antioxidants, weathering stabilizers, light resistance stabilizers, antiblocking agents, and lubricants, within the scope of the present disclosure.

[0039] The average fiber diameter of the fibers constituting the spunbonded nonwoven fabric is preferably 0.05 μm to 100 μm. When the average fiber diameter of the nonwoven fabric is 0.05 μm or more, sufficient mechanical strength, specifically tensile strength, is obtained, making it less likely to break and resulting in superior handling properties of the packaging material. When the average fiber diameter of the nonwoven fabric is 100 μm or less, the thickness of the nonwoven fabric is less likely to increase, making it easier to adjust the breathability and moisture permeability to an appropriate range, which is preferable. From the same viewpoint, the average fiber diameter of the nonwoven fabric is more preferably 20 μm to 100 μm.

[0040] The average fiber diameter of the fibers constituting the nonwoven fabric can be measured using an electron microscope. For example, a photograph of the surface of the nonwoven fabric is taken at 1000x magnification using an electron microscope. From the photograph, 100 fibers are randomly selected, and the diameters (widths) of the selected fibers are measured. The arithmetic mean value can be calculated as the average fiber diameter.

[0041] The basis weight of the spunbond nonwoven fabric is preferably 10 g / m 2 ~100g / m 2 , more preferably 15 g / m 2 ~60g / m 2The fiber diameter (average fiber diameter) of the spunbond nonwoven fabric is preferably 8 μm to 50 μm, more preferably 13 μm to 40 μm, and even more preferably more than 20 μm and 35 μm or less. When the basis weight of the spunbonded nonwoven fabric is within the above range, the packaging member of the present disclosure has good flexibility and strength, and is able to better retain the fruit and vegetables contained therein. The method for measuring the basis weight of the spunbonded nonwoven fabric is the same as the method described in the Examples.

[0042] The thickness of the spunbond nonwoven fabric is not particularly limited and may be appropriately selected depending on the application. From the viewpoint of obtaining a packaging member that has a good balance between rigidity and flexibility, the thickness of the spunbond nonwoven fabric is preferably 40 μm to 200 μm, more preferably 40 μm to 150 μm, and even more preferably 50 μm to 120 μm. The method for measuring the thickness of the spunbond nonwoven fabric is the same as that described in the examples.

[0043] By having the packaging member of the present disclosure contain spunbond nonwoven fabric, it is possible to expect a moisturizing effect inside the packaging member due to the low-brightness gaps between the fibers of the spunbond nonwoven fabric, or a drug retention effect when a drug is used.

[0044] (resin layer) The packaging member of the present disclosure has a resin layer on at least the surface of the spunbond nonwoven fabric that comes into contact with the film, the resin layer covering at least a portion of the surface of the fibers that form the nonwoven fabric. By having the resin layer cover at least a portion of the fiber surface that forms the nonwoven fabric, in the packaging member of the present disclosure, the adhesion between the film and the spunbond nonwoven fabric is improved without impairing the breathability and moisture permeability of the film, preferably the perforated film and the spunbond nonwoven fabric, and interlayer delamination with the film nonwoven fabric is suppressed, resulting in a packaging member with good moisture permeability, flexibility, and strength.

[0045] Examples of resins (i.e., adhesives) used to form the resin layer include hot-melt adhesives, hydrocarbons, polyolefins, etc., and hot-melt adhesives are particularly preferred. This allows the nonwoven fabric and film to be bonded together without impairing the moisture permeability of the packaging material, as compared to when a solvent-based adhesive is used. This is presumably because a coating of a hot-melt adhesive is less likely to penetrate into the interior of the spunbond nonwoven fabric than a coating of a solvent-based adhesive. Paraffin wax is a preferred hot melt adhesive.

[0046] The amount of resin in the adhesive layer of the packaging member of the present disclosure (i.e., the amount of adhesive applied) is 3 g / m 2 More than 20g / m 2 Preferably, it is 4 g / m or less. 2 More than 15g / m 2 More preferably, it is: The resin amount in the adhesive layer is 4g / m 2 This ensures sufficient adhesive strength between the film and the spunbond nonwoven fabric, and the adhesive strength is 15 g / m 2 By satisfying the condition of 0.1 to 1.0 wt %, a flexible packaging member having good durability can be obtained without impairing moisture permeability.

[0047] The thickness of the packaging member of the present disclosure is preferably 150 μm (0.15 mm) to 500 μm (0.5 mm), more preferably 150 μm to 400 μm, and even more preferably 180 μm to 300 μm. When the total thickness of the packaging member is 150 μm or more, the strength and durability of the packaging member are good, and when the thickness is 400 μm or less, the flexibility and handling properties are better.

[0048] The weight of the packaging material can be adjusted depending on the application, but is usually 30 g / m 2 ~200g / m 2 is preferred, and 50 g / m 2 ~150g / m 2 More preferably, 60 g / m 2 ~110g / m 2 It is more preferable that the range is: By having the basis weight of the packaging material in the above range, the weight per unit area is not made too large, and workability when packaging fruits and vegetables is improved. The method for measuring the basis weight of the packaging material is the same as the method described in the Examples.

[0049] (Packaging material properties: moisture permeability) The moisture permeability of the packaging material of the present disclosure at 5°C is 200 g / m 2 24hr~1200g / m 2 24hr, 200g / m 2 24hr~1200g / m 2 24 hours is preferable, 200 g / m 2 24hr~1200g / m 2 24 hours is preferable. In the present disclosure, the moisture permeability is measured using the cup method according to JIS K6549 Z-0208, with the measurement temperature set to 5°C, which is close to the actual storage conditions. Specifically, to adjust the humidity to 95% Rh or higher at a measurement temperature of 5°C, a nonwoven fabric, Bemcot® M-II (manufactured by Ozu Industries), was cut into pieces the size of which would fit into one aluminum dish 43 mm in diameter and 12.7 mm deep, and placed inside a 40 μm thick J4 (240-340 / A4) zippered polyethylene bag. One piece was allowed to absorb 10 ml of water, three test pieces were prepared for each packaging material, and three sets of test specimens sealed in accordance with JIS K6549 Z-0208, and one data logger, "Ondotori TR-75nw (manufactured by T&D Co., Ltd.)," were placed inside, and the zipper was closed to seal the bag. The bag was then placed in a refrigerator adjusted to 5°C, and it was confirmed that the temperature inside the bag had reached 5°C and the humidity had reached 95% Rh. Two hours later, the test began and the cup weight was measured, and then it was measured again at 24-hour intervals, with the end point being 72 hours. The average value of the three test packaging materials was calculated and used as the moisture permeability.

[0050] It is believed that by having the moisture permeability of the packaging material of the present disclosure be in the above range, secondary effects can be achieved, such as preventing spoilage and odor generation of fruits and vegetables by maintaining good humidity inside the packaging material, and preventing weight changes due to moisture absorption by cardboard used in combination.

[0051] (Packaging material properties: total light transmittance) The average total light transmittance in the wavelength range of 320 nm to 780 nm in the optical spectrum of the packaging material of the present disclosure is 1.00% or less, preferably 0.95% or less, and more preferably less than 0.9%. When the total light transmittance of the packaging material in the above wavelength range is 1.00% or less, deterioration of fruits and vegetables due to their photoresponse, more specifically, flowering, yellowing, and undesired germination of broccoli, rape blossoms, etc., is effectively suppressed.

[0052] The total light transmittance in the present disclosure is measured by the following method. The measurement is carried out by the UV-VIS method. Equipment used: Shimadzu UV-31008 Reference side No sample Measurement wavelength 800nm-200nm Scan speed: Medium Sample pitch 1.0nm The packaging material of the present disclosure is cut into three 3 cm square test pieces, and the total light transmittance of each is measured. The average value of the three measurements is taken as the total light transmittance.

[0053] It is particularly preferable that the average value of the total light transmittance in the wavelength range of 600 to 780 nm, among the wavelength range of 320 to 780 nm, is 0 to 10% from the viewpoint of improving the heat shielding properties.

[0054] (Packaging material properties: brightness) The packaging member of the present disclosure has, on at least one surface, a hue lightness L in the CIE1976 (La*b*) color space of 40 or less. The lightness L is preferably 35 or less, and more preferably 30 or less. The lightness is measured using the L value (lightness) with a Konica Minolta Color Reader color difference meter CR-20. In the present disclosure, measurements are repeated three times at different measurement locations, and the average value is used. In particular, from the viewpoint of freshness-preserving effect, it is preferable that the packaging member of the present disclosure has a hue lightness L of 40 or less in the CIE1976 (La*b*) color space at least on the surface facing the fruit or vegetable. One embodiment of the packaging member of the present disclosure is a bag-shaped packaging member that is formed into a bag shape and is used to place contents inside. Furthermore, in the present disclosure, it is more preferable that the product is formed into a bag shape and used to place inclusions inside, and that the brightness L of one side is 40 or less and the brightness L of the other side is 70 to 100, and that the side with the brightness L of 40 or less is the side facing the inclusions. Hereinafter, the surface of the packaging material opposite to the surface on the inclusion side may be referred to as the outer surface. Also, the surface on the inclusion side may be referred to as the inclusion side, and the surface opposite to the inclusion surface may be referred to as the outer surface side. By setting the brightness L of the surface facing the inclusions to 40 or less and the brightness L of the opposite side, i.e., the outer surface which is more susceptible to the influence of external light, to 70 to 100, external light is reflected by the outer surface, and the low brightness of the surface facing the inclusions causes the transmitted light to be absorbed, more effectively suppressing the light from reaching the inclusion fruits and vegetables and the influence of external temperature, thereby more effectively maintaining the freshness of the fruits and vegetables. The lightness L of the outer surface is preferably 70-100, and more preferably 80-100.

[0055] In the packaging member of the present disclosure, the outer surface may be colored to achieve a brightness of 70 or more. For example, porous films containing inorganic fillers are often white, while polyolefin resin films are often transparent. Furthermore, nonwoven fabrics containing fibers such as the aforementioned polyester resins and polyolefin resins are often nearly white. When the outer surface of the packaging member is white and the brightness L is set to 70 or more, the film or nonwoven fabric on the outer surface may be colored white. On the other hand, the surface of the packaging material that faces the contents is preferably non-white, preferably dark, close to black.

[0056] The dark black coloring preferably includes a dark colorant (e.g., a black dye or pigment). Examples of black dyes or pigments include inorganic black pigments such as carbon black and graphite; and organic black dyes or pigments such as azo dyes or pigments, aniline black, and sulfide dyes. These black dyes or pigments can be used alone or in combination.

[0057] (Manufacturing method of packaging material) There are no particular limitations on the method for producing the packaging member of the present disclosure, and any known method for producing a laminate in which a film, an adhesive layer, and a spunbond nonwoven fabric are laminated in this order can be applied. Among these, a preferred production method includes the steps of: preparing a black spunbond nonwoven fabric according to information using a resin containing a black pigment such as carbon black as the fiber resin for the nonwoven fabric; adding a filler such as calcium carbonate to the resin, melt-forming the resulting resin into a film, and stretching it to obtain a perforated film; and applying a resin for forming an adhesive layer, i.e., an adhesive, to the spunbond nonwoven fabric, laminating the perforated sheet on the applied surface, and preferably pressing them together to obtain a packaging member. The step of preparing the nonwoven fabric and the step of obtaining the perforated film may be performed in either order, or may be performed simultaneously as separate steps. The method for applying the adhesive is not particularly limited, and a known method may be appropriately selected depending on the type of adhesive. Examples of application methods include spray coating, bead coating, slot coating, curtain coating, gravure coating, Mayer bar coating, scattering, and melt extrusion lamination. To ensure moisture permeability of the packaging material, the adhesive layer is preferably interposed in at least a portion of the fibers constituting the nonwoven fabric. Among these, spray coating is preferred from the viewpoint of uniformly applying the adhesive to the interface between the film and the spunbond nonwoven fabric (i.e., the surface of the nonwoven fabric to which the adhesive is applied).

[0058] The method for laminating the nonwoven fabric and the film is not particularly limited, and any known method may be used, such as dry lamination or melt lamination.

[0059] The method for manufacturing the packaging member of the present disclosure is not limited to the above. The resulting packaging member of the present disclosure can be used to package fruits and vegetables, and can effectively maintain the freshness of the fruits and vegetables contained therein. The fruits and vegetables are not particularly limited, but are preferably used for fruits and vegetables that are susceptible to photoresponse, for example, leafy vegetables such as broccoli, rape blossoms, spinach, and Japanese mustard spinach, tubers such as potatoes and sweet potatoes, flowers, etc. In the present disclosure, the term "fruits and vegetables" is used to encompass flowers that are susceptible to photoresponse, such as flowers or leaves.

[0060] [Methods for keeping fruits and vegetables fresh] The method for preserving the freshness of fruits and vegetables disclosed herein includes a package preparation process in which the previously described freshness-preserving packaging material disclosed herein is formed into a bag shape and the fruits and vegetables are placed inside the bag-shaped freshness-preserving packaging material to produce a package, and an adjustment process in which the average humidity inside the obtained package is adjusted to 95% to 99%. The adjusting step is preferably carried out at a temperature of 20° C. or less.

[0061] Examples of a method for adjusting the average humidity inside the obtained package to 95% to 99% include a method for preventing the wind from the refrigerator or storage cabinet from blowing into the inside of the package by folding up the opening of the package, temporarily sealing it with masking tape, etc. Furthermore, a method can also be used in which a storage cabinet that is cooled in a windless state inside the cabinet, such as a vegetable compartment of a refrigerator or a constant temperature and humidity cabinet manufactured for preserving fruits and vegetables, is used. For example, when fruits and vegetables with a moisture content of 95% are packaged, moisture evaporates from the fruits and vegetables, so the humidity inside the package is generally maintained at 95% to 99% until the packaged fruits and vegetables are completely dried. Therefore, by keeping the inside of the package in a state where air drying due to air blowing in is suppressed, it becomes easier to maintain the desired humidity.

[0062] The packaging method may be, for example, a method in which the outside of a cardboard box containing fresh produce is covered with a packaging member of the present disclosure formed into a bag shape (a method in which the packaging member of the present disclosure is used as the outer bag), a method in which the fresh produce is placed directly into a packaging member of the present disclosure formed into a bag shape and stored as is, or a method in which the bag containing the fresh produce is further placed into a cardboard box (a method in which the packaging member of the present disclosure is used as the inner bag). [Example]

[0063] The present disclosure will be described in more detail below based on examples, but the present disclosure is not limited to these examples.

[0064] [1]Measurement method Physical properties in the examples and comparative examples were measured by the following methods.

[0065] [1.1] Nonwoven fabric weight (g / m 2 ) Ten test pieces measuring 100 mm in the machine direction (MD) × 100 mm in the cross direction (CD) were taken from the nonwoven fabric, and the weight of the nonwoven fabric was calculated from the measured mass. The average weight of the 10 test pieces was recorded as "weight (g / m)". 2 )"

[0066] [1.2] Thickness (mm) Ten test pieces measuring 100 mm in the machine direction (MD) × 100 mm in the cross direction (CD) were taken from the freshness-preserving packaging material. The thickness of the freshness-preserving packaging material (total) was measured using a digital film thickness meter ID-F125 (Mitutoyo Corporation). When the packaging member consisted of a film alone, the thickness was measured in the same manner as above. The average thickness of each of the 10 test pieces was recorded as "thickness (mm)." Since it is difficult to peel off a laminate of a film and a nonwoven fabric, the basis weight of the film is recorded as the value obtained by subtracting the basis weight of the nonwoven fabric from the basis weight of the packaging member.

[0067] [1.3] Adhesive usage (g / m 2 ) The amounts of adhesive used are as shown in Tables 1 and 2.

[0068] [1.4] Moisture permeability Measurement was performed in accordance with the cup method described in JIS K 6549 Z-0208. The measurement was performed in the same manner, except that the measurement temperature was set to 5°C, which is close to the actual storage conditions. Specifically, to adjust the humidity to 95% or more at a measurement temperature of 5°C, nonwoven fabric (Bencott R M-II (manufactured by Ozu Sangyo)) cut into pieces the size of which would fit into an aluminum dish 43 mm in diameter and 12.7 mm deep was placed inside a 40 μm thick polyethylene bag with a zipper (J4 240-340 / A4), and one piece was allowed to absorb 10 ml of water. Three test pieces were prepared for each packaging material, and three sets of test specimens sealed in accordance with JIS K6549 Z-0208 were placed inside, along with one data logger "Ondotori TR-75nw (manufactured by T&D Co., Ltd.)", and the bag was then sealed by closing the zipper. The bags were then placed in a refrigerator adjusted to 5°C, and the test began once it was confirmed that the temperature inside the bags had reached 5°C and 95% Rh. The average value of the three test packaging materials was calculated and used as the moisture permeability. Measurements were carried out three times, and the average value of the three measurements was rounded to an integer according to Rule B (rounding method) of JIS Z 8401, and the moisture permeability (g / m 2 / 24hr).

[0069] [1.5] Total light transmittance from 320nm to 780nm The total light transmittance of the freshness-preserving packaging material was measured by the following method. The measurement was carried out by the UV-VIS method. Equipment used: Shimadzu UV-31008 Reference side No sample Measurement wavelength 800nm-200nm Scan speed: Medium Sample pitch 1.0nm Three test pieces of 3 cm square were cut out from each of the packaging members of the Examples and Comparative Examples, and the total light transmittance of each was measured, and the average value of the three measurements was taken as the total light transmittance.

[0070] [1.6] Hue lightness L in the CIE1976 (La*b*) color space The lightness L was measured using the L value (lightness) with a Color Reader color difference meter CR-20 manufactured by Konica Minolta. In each example and comparative example, measurements were repeated three times at different measurement locations, and the average value was used. Measurement was performed by the UV-VIS method. The measurement device used was a UV-31008 manufactured by Shimadzu Corporation. The measurement was repeated three times at different measurement locations, and the average value was taken as the "total light transmittance."

[0071] [2] Manufacturing of packaging members of examples and comparative examples [Example 1] Layer structure of packaging member of Example 1: black spunbond nonwoven fabric / adhesive layer / white porous film

[0072] [Preparation of nonwoven fabric] The thermoplastic resin composition was melt-spun at 230°C in a spunbond nonwoven fabric molding machine having a spinning nozzle with a diameter of 0.6 mm using 92.7 parts by mass of a propylene homopolymer having a melt flow rate (MFR) of 60 g / 10 min (ASTM D-1238, 230°C, load 2,160 g), 3.3 parts by mass of a hindered amine light stabilizer as a light stabilizer, and 4.0 parts by mass of a black masterbatch obtained by kneading 20% ​​by mass of carbon black and 80% by mass of a polypropylene resin having an MFR of 60 g / 10 min (ASTM D-1238, 230°C, load 2,160 g). The resulting fibers were deposited on a collecting surface and embossed (embossed area ratio: 10%) to produce a fiber with a diameter of 22 μm and a basis weight of 40 g / m. 2 A black spunbond nonwoven fabric of 100g was obtained.

[0073] [Preparation of porous film] Linear low-density polyethylene (density: 0.92 g / cm 3 , MFR (ASTM D-1238, 190°C, load 2,160g): 2g / 10min) 38.0 parts by mass, branched low-density polyethylene (density: 0.92g / cm 32.0 parts by mass of ethylene bisstearic acid amide (MFR: 4g / 10 min), 60.0 parts by mass of calcium carbonate (average particle size 1.1 μm), 3.0 parts by mass of ethylene bisstearic acid amide, and 3.3 parts by mass of a hindered amine-based light stabilizer were mixed in a tumbler mixer, and then uniformly kneaded at 230°C using a tandem kneading extruder and processed into pellets. The pellets were melt-formed into a film at 260°C using an extruder equipped with a T-die. The film was uniaxially stretched in the machine direction at a stretch ratio of 3.5 times and a line speed of 80 m / min between a preheating roll heated to 75°C and a stretching roll, resulting in a film with a basis weight of 40 g / m. 2 A film of

[0074] Spunbond nonwoven fabric with olefin thermoplastic resin at 10g / m as adhesive layer. 2 is sprayed onto the coated surface, a perforated film is placed over it, and then it is heated and pressurized with a heated roll (hereinafter also referred to as "hot melt laminating") to produce a fabric with a basis weight of 78 g / m 2 The packaging material was produced. The resulting packaging member of Example 1 was evaluated by the methods described above, and the results are shown in Table 1. The packaging member of Example 1 was formed into a bag shape with a size of (W) 600 mm x (D) 400 mm x (H) 850 mm, which had one opening, and was subjected to a storage test described later.

[0075] [Example 2] The laminate of the film, adhesive layer, and nonwoven fabric obtained in Example 1 was molded into a bag shape with a size of (W) 600 mm × (D) 400 mm × (H) 850 mm, with one opening, to obtain the packaging material of Example 2, which was subjected to a storage test described below under conditions different from those of Example 1. [Example 3] The laminate of the film, adhesive layer, and nonwoven fabric obtained in Example 1 was molded into a bag with a size of (W) 485 mm × (D) 365 mm × (H) 690 mm, with one opening, to obtain the packaging material of Example 3, which was subjected to the storage test described below under conditions different from those of Example 1. [Example 4] The laminate of the film, adhesive layer, and nonwoven fabric obtained in Example 1 was formed into a bag shape with a size of (W) 420 mm × (D) 320 mm × (H) 690 mm, with one opening, to obtain the packaging member of Example 4, which was subjected to a storage test described below under conditions different from those of Example 1.

[0076] [Comparative Example 1] Commercially available product weight: 128g / m 2 Tyvek (registered trademark) 760AG (Asahi DuPont Flash Spun Products Co., Ltd.) was molded into a bag shape of the same size as in Example 3 to form a packaging member for Comparative Example 1. Comparative Example 2 Commercially available product weight: 128g / m 2 Tyvek (registered trademark) 760AG (Asahi DuPont Flash Spun Products Co., Ltd.) was molded into a bag shape of the same size as in Example 4 to form a packaging member for Comparative Example 2.

[0077] Comparative Example 3 Layer structure of packaging member of Comparative Example 1: spunbond nonwoven fabric / meltblown nonwoven fabric / spunbond nonwoven fabric A propylene homopolymer with a melt flow rate (MFR) of 60 g / 10 min (ASTM D-1238, 230°C, load 2,160 g) was used to form fibers by melt spinning at a melt temperature of 230°C with a spinneret of 0.6 mmφ, to form a spunbond nonwoven fabric layer. Next, a propylene homopolymer having a melt flow rate (MFR) (ASTM D-1238, 230°C, load 2,160 g) of 400 g / 10 min was used, and a molten material melted at a melting temperature of 280°C was extruded from a spinneret, and heated air at 280°C was blown onto the outlet of the spinneret's nozzles to form fibers by a meltblown method. The formed fibers were deposited on the spunbond nonwoven fabric layer to form a meltblown nonwoven fabric layer. Next, a spunbond nonwoven fabric layer was formed on the meltblown nonwoven fabric layer under the same conditions as for forming the spunbond nonwoven fabric layer, thereby obtaining a laminate having a layered structure in which a spunbond nonwoven fabric layer, a meltblown nonwoven fabric layer, and a spunbond nonwoven fabric layer were arranged in this order.

[0078] Next, the obtained laminate was embossed under the conditions of an embossed area ratio of 18% and an embossing temperature of 145°C, thereby integrating the spunbond nonwoven fabric layer, the meltblown nonwoven fabric layer, and the spunbond nonwoven fabric layer, and forming a laminate with a basis weight of 55 g / m 2 The SMS nonwoven fabric (synthetic fiber nonwoven fabric) was obtained and used as a packaging member of Comparative Example 3.

[0079] Comparative Example 4 A commercially available polyester film (PE) having a thickness of 20 μm was used as the packaging material of Comparative Example 4.

[0080] Comparative Example 5 Layer structure of packaging member of Comparative Example 5: spunbond nonwoven fabric / meltblown nonwoven fabric / spunbond nonwoven fabric / adhesive layer / polyethylene film Melt flow rate (MFR) (ASTM D-1238, 190°C, 2,160g load) 30g / 10min, density 940kg / m 3 A spunbond nonwoven fabric layer was formed by melt spinning medium-density polyethylene at a melt temperature of 230°C using a spinneret of 0.6 mm in diameter. Next, a medium-density polyethylene with a melt flow rate (MFR) (ASTM D-1238, 190°C, load 2,160 g) of 100 g / 10 min and a density of 940 kg / m3 was used, and a molten material melted at a melting temperature of 280°C was extruded from a spinneret, and heated air at 280°C was blown onto the outlet of the spinneret's discharge holes by a meltblown method to form fibers. The formed fibers were deposited on the spunbond nonwoven fabric layer to form a meltblown nonwoven fabric layer. Next, a spunbond nonwoven fabric layer was formed on the meltblown nonwoven fabric layer under the same conditions as for forming the spunbond nonwoven fabric layer, thereby obtaining a laminate having a layered structure in which a spunbond nonwoven fabric layer, a meltblown nonwoven fabric layer, and a spunbond nonwoven fabric layer were arranged in this order. Next, the obtained laminate was embossed under the conditions of an embossed area ratio of 18% and an embossing temperature of 145°C, thereby integrating the spunbond nonwoven fabric layer, the meltblown nonwoven fabric layer, and the spunbond nonwoven fabric layer, and forming a laminate with a basis weight of 25 g / m 2 As a result, an SMS nonwoven fabric (synthetic fiber nonwoven fabric) was obtained. The obtained SMS nonwoven fabric was coated with 25 g / m of olefin thermoplastic resin as an adhesive layer. 2 A linear low-density polyethylene film (TUX-FUD-NP manufactured by Mitsui Chemicals Tohcello) was then placed on top of it, and the film was then hot-melted and laminished to a basis weight of 38.4 g / m. 2 A packaging member of Comparative Example 5 was produced.

[0081] Comparative Example 6 A commercially available polypropylene film (PP) having a thickness of 20 μm was used as the packaging material of Comparative Example 6.

[0082] [Physical property evaluation] Each packaging material was formed by the method described in Example 1 above, and stored under the following conditions. The physical properties of the broccoli after storage were evaluated. The results are shown in Table 1. The storage conditions below are those intended for export, and involve packing broccoli into a cardboard box, which is then wrapped in a bag made from each packaging component (outer bag), or packing broccoli into each packaging component, which is then packed into a cardboard box (inner bag), and storing the product at a storage temperature of 2°C for 14 days.

[0083] [Evaluation of freshness preservation method: outer bag] A number of broccoli heads were directly packed into a cardboard box measuring 420 mm (W) × 330 mm (D) × 240 mm (H), and the cardboard box was closed, after which the broccoli heads were packaged using the packaging materials of Example 1 and Comparative Examples 1 to 3. The packaging materials were packaged using the test packaging materials. The openings of the packaging materials were folded and sealed, but the packaging materials were not airtight.

[0084] [Evaluation of freshness preservation method: inner bag] Each bag-shaped packaging element was placed in a cardboard box measuring (W) 420 mm x (D) 330 mm x (H) 240 mm, and 12 broccoli heads for the May harvest and 20 broccoli heads for the November harvest were packed inside the packaging element. The top opening of the packaging element was simply folded over to form the package, and the product was stored at 2°C for 14 days. The packaging member is in an unsealed state. The same items as in Example 1 were evaluated, and the results are shown in Table 1. The fruits and vegetables stored in the packaging materials were evaluated as follows after storage. The results are shown in Table 1.

[0085] (1. Weighing) Before the start of the test and after 14 days of storage at 1°C, the weights of each box, test packaging material, and broccoli were measured, and the change in weight compared to before the start of the test was calculated. The change in box weight indicates the amount of water absorbed by the box. If the box absorbs a large amount of water, for example, if the weight increase rate exceeds 15%, the box will soften and may collapse when stacked or the bottom may fall out when carried, so it was deemed to have failed. The change in weight of the packaging material indicates the amount of condensation that occurs inside the packaging material, and if the amount of condensation is large, it can cause mold and decay. The change in weight of broccoli indicates the degree of wilting, the amount of buds that have fallen, etc.

[0086] (2. Sensory evaluation: appearance, presence or absence of unpleasant odor) The broccoli was visually assessed for mold, yellowing or browning of the florets, and decay, and its texture was assessed for wilting. The olfactory sense was also used to assess the presence or absence of off-flavors. These sensory assessments were performed by at least three people with experience in assessing the freshness of fruits and vegetables.

[0087] [Table 1]

[0088] In Tables 1 and 2, "PE" refers to polyethylene, "PP" refers to propylene homopolymer, and "HDPE" refers to high-density polyethylene.

[0089] The evaluation results showed that the sheet had a film, a spunbond nonwoven fabric, and a resin layer in this order, an average total light transmittance in the wavelength range of 320 nm to 780 nm of 1.0% or less, and a moisture permeability of 200 g / m at 5°C. 2 24hr~1200g / m 2 The packaging members of each Example, which had a durability of 24 hours and a lightness L of 40 or less on at least one side, were better than the respective Comparative Examples in all of the above evaluations, with a non-defective product rate of 95% or more and good performance in preventing deterioration of fruits and vegetables.

[0090] [Examples 5 and 6] The packaging members of Examples 5 and 6 were formed into a bag shape with the same size as the packaging members of Examples 2 to 4 described above, and were evaluated under the following storage conditions.

[0091] [Comparative Examples 7 to 8] The Tyvek (registered trademark) 760AG (Asahi DuPont Flash Spun Products Co., Ltd.) used in Comparative Examples 1 and 2 was molded into bags of the same size as those in Comparative Examples 1 and 2, respectively, to form the packaging materials for Comparative Examples 7 and 8. Comparative Example 9 A commercially available polypropylene film (PP) having a thickness of 20 μm was formed into a bag of the same size as that of Comparative Example 6 to form a packaging member for Comparative Example 9.

[0092] [Physical property evaluation] The packaging materials obtained above were stored under the following conditions, and the physical properties of the broccoli after storage were evaluated. The results are shown in Table 2. In Table 2, "-" indicates that the evaluation was not performed. The storage conditions below simulate the conditions that would occur after refrigerated storage for four days at a store after storage for export. After storing packages filled with broccoli for export at a storage temperature of 2°C for 14 days, the packaging material intended for retail sale was removed and the broccoli was placed directly into the box and stored at 7°C for four days.

[0093] [Table 2]

[0094] The evaluation results showed that the sheet had a film, a spunbond nonwoven fabric, and a resin layer in this order, an average total light transmittance in the wavelength range of 320 nm to 780 nm of 1.0% or less, and a moisture permeability of 200 g / m at 5°C. 2 24hr~1200g / m 2 The packaging members of each Example, which had a durability of 24 hours and a lightness L of 40 or less on at least one side, were better than the respective Comparative Examples in all of the above evaluations, had a non-defective product rate of 90% or more, and were good at preventing deterioration of fruits and vegetables.

Claims

1. The nonwoven fabric has, in this order, a film, a spunbonded nonwoven fabric, and a resin layer on at least the surface of the spunbonded nonwoven fabric that comes into contact with the film, the resin layer covering at least a part of the surface of the fibers that form the nonwoven fabric; the average value of the total light transmittance in the wavelength range of 320 nm to 780 nm in the spectroscopic spectrum is 1.00% or less; Moisture permeability at 5°C is 200g / m ２ ・24hr~1200g / m ２ 24 hours, A freshness-preserving packaging member having a hue lightness L of 40 or less in the CIE1976 (La*b*) color space on at least one surface.

2. 10. The freshness-modifying packaging member of claim 1, wherein the film is a perforated film.

3. The freshness-preserving packaging member of claim 2 , wherein the perforated film comprises a thermoplastic resin and a filler.

4. 2. The freshness-preserving packaging member according to claim 1, wherein the fibers forming the spunbond nonwoven fabric are made of one or more resins selected from the group consisting of polyethylene, polypropylene, and polyethylene terephthalate.

5. The freshness-preserving packaging member according to claim 3, wherein the thermoplastic resin comprises one or more resins selected from the group consisting of polyethylene, polypropylene, and polyethylene terephthalate.

6. The freshness-preserving packaging material according to claim 1, wherein the thickness of the film is in the range of 50 μm to 1 mm.

7. It is formed into a bag shape and is used to put inclusions inside. The brightness L of one surface is 40 or less, and the brightness L of the other surface is 70 to 100, The freshness-preserving packaging material according to claim 1, wherein the surface having a brightness L of 40 or less is the surface facing the contents.

8. a package fabrication process for forming the freshness-maintaining packaging material according to claim 1 into a bag shape and placing fruits and vegetables inside the bag-shaped freshness-maintaining packaging material to fabricate a package; and an adjusting step of adjusting the average humidity inside the obtained package to 95% to 99%.

9. 9. The method for preserving the freshness of fruits and vegetables according to claim 8, wherein the adjusting step is carried out at a temperature of 20°C or lower.

Images