阅读说明：本技术 包装材料及其使用方法 (Packaging material and method of use thereof ) 是由 池山昭弘 片野祥吾 于 2018-11-06 设计创作，主要内容包括：本发明提供一种即使将密封包装有蔬果等的包装体冷藏并长期保存,在包装材料内侧也不会发生结露且抑制被包装物变干的包装材料及其使用方法。包装材料由具有含有纤维素酰化物的基材(11)和树脂层(12)的层叠膜(10、50)构成。树脂层(12)形成于基材(11)的一表面(11a),并含有丙烯酸树脂与纤维素衍生物的混合物、硅酮弹性体或氨基甲酸酯弹性体中的任一种。包装材料由在40℃、相对湿度90％下的透湿度在60g/m<Sup>2</Sup>·天以上且700g/m<Sup>2</Sup>·天以下的范围内的层叠膜(10、50)构成。(The invention provides a packaging material and a method of using the same, wherein even if a packaging body hermetically packaged with vegetables and fruits and the like is refrigerated and stored for a long time, condensation does not occur on the inner side of the packaging material, and the drying of the packaged object is suppressed. The packaging material is composed of a laminated film (10, 50) having a base material (11) containing a cellulose acylate and a resin layer (12). The resin layer (12) is formed on one surface (11a) of the base material (11), and contains any one of a mixture of an acrylic resin and a cellulose derivative, a silicone elastomer, and a urethane elastomer. The packaging material has a moisture permeability of 60g/m at 40 deg.C and 90% relative humidity 2 Day or more and 700g/m 2 A laminated film (10, 50) in a range of days or less.)

1. A packaging material comprising a laminated film, wherein,

the laminated film comprises a base material and a resin layer formed on one surface of the base material, and has a moisture permeability of 60g/m at 40 ℃ and a relative humidity of 90%²Day or more and 700g/m²In the range of up to day,

the substrate contains a cellulose acylate,

the resin layer contains any one of a composition composed of an acrylic resin and a cellulose derivative, a silicone elastomer, and a urethane elastomer.

2. The packaging material of claim 1,

the moisture permeability resistance per 1 μm thickness of the resin layer calculated from the moisture permeability at 40 deg.C and relative humidity of 90% is 3.0 × 10^-5(m²Day/g)/μm or more and 7.5 × 10^-4(m²Day/g)/μm or less.

3. The packaging material of claim 1 or 2,

the laminated film includes a saponification layer formed on the other surface of the base material on the side opposite to the one surface,

the saponified layer contains a saponified cellulose acylate.

4. The packaging material according to any one of claims 1 to 3, wherein,

the base material contains any one of an ester derivative of monosaccharide, an ester derivative of polysaccharide, an ester oligomer, or a propylene polymer.

5. The packaging material according to any one of claims 1 to 4,

the thickness of the laminated film is in the range of 10 [ mu ] m or more and 120 [ mu ] m or less.

6. The packaging material according to any one of claims 1 to 5, which is in a bag shape with the resin layer disposed outside.

7. The packaging material according to any one of claims 1 to 5, which is in a box shape in which the resin layer is disposed on the outer side.

8. The packaging material according to any one of claims 1 to 5, which is in a cylindrical shape with the resin layer disposed outside.

9. A packaging material according to any one of claims 1 to 8, having a folded portion of the laminated film.

10. The packaging material according to any one of claims 1 to 9, for packaging plants.

11. Packaging material according to any one of claims 1 to 9 for packaging vegetables and fruits.

12. A packaging material according to any one of claims 1 to 9 for use in packaging a food product.

13. A method of using the packaging material of any one of claims 1 to 12, which hermetically packages packaged objects with the packaging material.

Technical Field

The invention relates to a packaging material and a using method thereof.

Background

When preserving vegetables, fruits and other plants, it is important to prevent the freshness from being decreased. For example, vegetables and fruits are packaged with a packaging material in order to prevent the vegetables and fruits from rotting, drying, and the like due to respiration. When the vegetables and fruits are packed with the packing material, the vegetables and fruits can be prevented from drying. On the other hand, when the package is sealed, the following problems sometimes occur: in particular, moisture condensation occurs on the inner side of the packaging material, the vegetables and fruits become moldy, and the color of the vegetables and fruits changes due to moisture adhering thereto. Therefore, it is preferable that condensation does not occur, and this is particularly important for long-term storage.

As a packaging method for preventing condensation inside a packaging material and preserving vegetables and fruits for a long period of time, MA (Modified Atmosphere) packaging, antifog packaging for preventing condensation inside a packaging material, and the like have been used. For example, as MA packaging, a packaging film, which is a laminated film having oxygen barrier property and moisture permeability and including a base material having oxygen barrier property and moisture permeability, an anchor coat layer, and a thermoplastic resin layer formed in a stripe shape, is disclosed (patent document 1). As the substrate having oxygen barrier properties and moisture permeability, a polyamide film, a film obtained by laminating the polyamide film with another film, or the like can be used. The following are described: the packaging film has oxygen barrier property, but has a moisture permeability of 100g/m according to JIS K-0208²MPa · day or more, therefore, even when sealed, excess water vapor can be discharged to the outside, oxygen barrier properties are high, and oxidative deterioration of the contents is prevented, whereby the contents can be stored for a long period of time.

As a film whose moisture permeability is controlled by a film made of a resin having moisture permeability such as cellulose triacetate, a laminated film is disclosed as an optical film having a layer made of a specific curable composition, in which a film made of a resin having moisture permeability such as cellulose triacetate is used as a base film (patent document 2). The film is described as an optical film with reduced moisture permeability.

Disclosure of Invention

Technical problem to be solved by the invention

The film of patent document 1 has moisture permeability and is made of polyamide, and therefore, there is a possibility that condensation cannot be sufficiently prevented. Further, since the moisture permeability is as described above, after the storage for 1 week, the moisture content of the content is gradually released to the outside and the surface of the content may be excessively dried (patent document 1, reference example 3), and thus it is not sufficient to prevent the drying of the content. Therefore, when vegetables and fruits are packed with the packing material and stored for a long period of time, the vegetables and fruits gradually dry, and thus may not be preserved. Further, since the film is made of polyamide, when contents are packaged and moisture permeability is exhibited, there is a possibility that the packaging material is deformed such as stretched by moisture absorbed by polyamide.

The film of patent document 2 is used as an optical film, and when the film is processed into a bag-like or box-like packaging material for vegetables and fruits, the folded portion may be broken or the like. In many cases, the contents are put into a packaging material processed into a shape such as a bag or a box and then used in a sealed state, and in order to sufficiently exhibit the effect of adjusting the humidity of the space in the packaging material, it is necessary that the portion of the packaging material to be bent is not cracked or damaged. Further, when the package is stored for a long period of time, it is preferable that the packaging material is not deformed such as stretched or wrinkled due to humidity or the like during long-term storage. As described above, further improvement of packaging materials for vegetables and fruits is demanded. In the present specification, the term "package" refers to a combination of a stored article or the like and a packaging material such as a packaging bag, and the term "packaging material" refers to the packaging material itself such as a packaging bag.

Accordingly, an object of the present invention is to provide a packaging material and a method of using the same, in which even when a packaged body hermetically packed with vegetables and fruits or the like is refrigerated and stored for a long period of time, condensation does not occur inside the packaging material, and drying of the packaged object is suppressed.

Means for solving the technical problem

In order to solve the above problems, the packaging material of the present invention is formed of a laminated filmWherein the laminated film comprises a base material and a resin layer formed on one surface of the base material, and has a moisture permeability of 60g/m at 40 ℃ and a relative humidity of 90%²Day or more and 700g/m²Within a range of days or less. The substrate contains cellulose acylate. The resin layer contains any one of a composition composed of an acrylic resin and a cellulose derivative, a silicone elastomer, and a urethane elastomer.

Preferably, the moisture permeability resistance of the resin layer per 1 μm thickness calculated from the moisture permeability at 40 ℃ and 90% relative humidity is 3.0 × 10^-5(m²Day/g)/μm or more and 7.5 × 10^-4(m²Day/g)/μm or less.

Preferably, the laminated film contains a saponified layer formed on the other surface of the substrate on the side opposite to the one surface, and the saponified layer contains a saponified cellulose acylate.

Preferably, the base material contains any one of an ester derivative of monosaccharide, an ester derivative of polysaccharide, an ester oligomer, or a propylene polymer.

The thickness of the laminated film is preferably in the range of 10 μm to 100 μm.

The resin layer is preferably arranged in a bag shape. Further, the resin layer is preferably in a box shape disposed on the outside. Further, the resin layer is preferably arranged in a cylindrical shape on the outer side. It is preferable to have a bent portion of the laminated film.

Preferably the packaging material is used for packaging plants. And, preferably, for packaging vegetables and fruits. And, preferably, for packaging food products.

The method of using the packaging material of the present invention is preferably a method of hermetically packaging an object to be packaged with a packaging material.

Effects of the invention

The packaging material of the present invention prevents dew condensation from occurring on the inner side of the packaging material and prevents the object to be packaged from drying even when the packaging material hermetically packed with vegetables and fruits is refrigerated and stored for a long period of time. Further, according to the method of using the packaging material of the present invention, vegetables and fruits can be stored in a fresh state for a long period of time.

Drawings

Fig. 1 is a schematic cross-sectional view of a laminated film.

Fig. 2 is a schematic view of a packaging material in the shape of a bag.

Fig. 3 is a schematic view of a packaging material in the shape of a cylinder.

Fig. 4 is a schematic view of a roll of packaging material.

Fig. 5 is a schematic view of a box-shaped packaging material.

Fig. 6 is a schematic view of a laminated film forming apparatus.

Fig. 7 is a schematic view of a sealed package.

Fig. 8 is a schematic cross-sectional view of a laminated film.

Fig. 9 is a schematic diagram of a laminated film forming apparatus.

Detailed Description

[ embodiment 1]

The packaging material of the present invention is composed of a laminated film. As shown in fig. 1, the laminated film 10 has at least a substrate 11 and a resin layer 12 and is formed into a film shape. The shape of the film is not limited, and may be a long film or a sheet such as a rectangle. The laminated film 10 may also have other layers.

The moisture permeability of the laminated film 10, which is determined according to JIS Z0208 and Condition B (40 ℃ C., relative humidity 90%) (hereinafter, the relative humidity is referred to as RH (relative humidity)), is 60g/m²Day or more and 700g/m²Within a range of days or less. More preferably at 90g/m²550g/m at a rate of more than day²Within a range of not more than day, more preferably 100g/m²Day or more and 450g/m²Within a range of days or less. In the present specification, the moisture permeability is defined as a moisture permeability determined according to JIS Z0208 and condition B (40 ℃, 90% RH).

The overall thickness T10 of the laminated film 10 including the substrate 11, the resin layer 12, and other layers (as the case may be) is preferably in the range of 10 μm to 120 μm. More preferably 20 μm or more and 100 μm or less, and still more preferably 30 μm or more and 80 μm or less.

The substrate 11 is a base of the laminated film 10 and a support for supporting the resin layer 12. And, depending on the situationWhen another layer is provided, the support functions as a support for supporting the other layer. The thickness T11 of the substrate 11 is in the range of 10 μm to 100 μm, preferably 20 μm to 80 μm. The moisture permeability of the substrate 11 is preferably 300g/m²Day or more and 2000g/m²Within a range of days or less.

In the present embodiment, the substrate 11 contains cellulose acylate. Thus, the substrate 11 is formed of cellulose acylate. The cellulose acylate is cellulose triacetate (triacetyl cellulose, hereinafter referred to as TAC) in the present embodiment, but is not limited to TAC, and may be another cellulose acylate different from TAC. The substrate 11 has a moisture permeability of 100g/m²More than day and 3000g/m²Within a range of up to day, preferably 200g/m²Day or more and 2500g/m²Within a range of up to day, more preferably 300g/m²Day or more and 2000g/m²Within a range of days or less.

Since the packaging material has the base material 11 containing the cellulose acylate, water absorption and water release are appropriately performed by a temperature change and a humidity change depending on the equilibrium moisture content of the cellulose acylate. That is, the humidity of the space inside the packaging material rises due to the moisture released from the packaged object, and the equilibrium moisture content of the cellulose acylate contained in the base material 11 rises. The substrate 11 absorbs water by the increase in the equilibrium water content. When the base material 11 absorbs moisture, the humidity in the space inside the packaging material decreases, and the equilibrium moisture content of the base material 11 decreases, thereby releasing the moisture. Since the cellulose acylate contained in the base material 11 has a water content ratio that is balanced with appropriate moisture absorption/desorption performance, even when the vegetable or fruit is packaged in a sealed state, the packaging material suppresses dew condensation on the surface of the vegetable or fruit side, i.e., the inner surface of the packaging material, while maintaining the inside of the packaging material at a moderately high humidity level that suppresses drying-out of the vegetable or fruit. Further, even if the outside temperature and/or humidity changes, the change in the inside humidity of the packaging material is suppressed to be smaller than the outside change. Further, the effect of suppressing the occurrence of condensation can be obtained even in cold storage and the effect can be maintained for a long period of time, for example, 14 days. As a result, the occurrence and proliferation of mold can be suppressed, and the vegetables and fruits can be preserved in a fresh state for a long period of time. As described above, the discoloration of the vegetable and fruit can be suppressed by maintaining the environment at a moderately high temperature and suppressing dew condensation.

With respect to cellulose acylate, a hydroxyl group of cellulose is esterified by a carboxylic acid and thus has an acyl group. The degree of substitution with acyl groups of the cellulose acylate contained in the substrate 11 is preferably in the range of 2.00 or more and 2.97 or less. When the degree of substitution with an acyl group is within the above range, deformation due to water absorption of the base material 11 caused by an increase in humidity inside the packaging material can be suppressed. As the degree of substitution with acyl groups is smaller, the amount of water absorbed by the cellulose acylate also increases, and thus deformation due to water absorption is likely to occur. Therefore, the degree of substitution with acyl groups of the cellulose acylate contained in the substrate 11 is preferably 2.00 or more. On the other hand, cellulose acylate having a degree of substitution with acyl group exceeding 2.97 is not easily synthesized. Therefore, the degree of substitution with acyl groups is preferably 2.97 or less.

The degree of substitution with acyl groups of the cellulose acylate contained in the substrate 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. It is also known that the degree of substitution with acyl groups is the ratio of esterification of the hydroxyl groups of cellulose with carboxylic acid, i.e., the degree of substitution with acyl groups.

The acyl group of the cellulose acylate constituting the substrate 11 is not particularly limited, and may be an acetyl group having 1 carbon atom or an acetyl 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, alkenylcarbonyl ester, aromatic carbonyl ester, and 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, cyclohexylcarbonyl group, oleoyl group, benzoyl group, naphthylcarbonyl group, cinnamoyl group and the like.

The acyl group of the cellulose acylate constituting the substrate 11 may be only 1 kind or 2 or more kinds, but preferably at least 1 kind is an acetyl group. Since the substrate 11 easily absorbs moisture by the cellulose acylate having an acetyl group, the effect of suppressing dew condensation and the like is further improved. Most preferred is cellulose acylate in which all of the acyl groups are acetyl groups, that is, cellulose acylate is more preferably cellulose acetate.

The degree of acyl substitution can be determined by a conventional method. For example, the degree of acetylation (degree of acetyl substitution) may be according to ASTM: the degree of acetylation in D-817-91 (test method for cellulose acetate, etc.) is determined by measurement and calculation. Further, the degree of acylation (degree of substitution with acyl) can also be measured by measuring the distribution thereof by high performance liquid chromatography. As an example of this method, the degree of acetylation of cellulose acetate is measured as follows: the sample was dissolved in methylene chloride, and the degree of acetic acid distribution was measured by linear gradient from a mixture of methanol and water as an eluent (the mass ratio of methanol to water was 8: 1) to a mixture of methylene chloride and methanol (the mass ratio of methylene chloride to methanol was 9: 1) using a column Novapac-phenyl (manufactured by Waters corporation), and the degree of acetic acid distribution was determined by comparison with a standard curve based on a standard sample having a different degree of acetic acid. These measurement methods can be obtained by referring to the methods described in japanese patent application laid-open No. 2003-201301. Since the sample is taken from the substrate 11 as containing an additive, the measurement of the acetylation degree of cellulose acylate is preferably based on the measurement by high performance liquid chromatography.

In order to form the substrate 11, a plasticizer is preferably added to the cellulose acylate. As the plasticizer for cellulose acylate, various known plasticizers can be used. Even if a plasticizer is used, condensation can be suppressed and discoloration of vegetables and fruits can be reliably suppressed. Examples of the preferred plasticizer include Triphenylacetate (TPP) and Biphenyl Diphenyl Phosphate (BDP), but various plasticizers can be used from the viewpoint of suppressing dew condensation and discoloration of vegetables and fruits. When the packaged material is a vegetable or fruit, various known plasticizers can be used as long as the safety is confirmed.

The substrate 11 preferably contains any of an ester derivative of a sugar, an ester oligomer, and a propylene polymer in addition to the cellulose acylate. The ester derivative and the ester oligomer of the saccharide function as a plasticizer for cellulose acylate. By using the plasticizer, the water content of the cellulose acylate can be adjusted, and the bending property that is not easily broken even when it is bent can be improved.

The ester derivative of the saccharide may be any one of an ester derivative of a monosaccharide and an ester derivative of a polysaccharide, and the substrate 11 may contain both of these. In view of safety when packaged vegetables and fruits are used as the sugar, monosaccharides such as glucose, galactose, mannose, fructose, xylose and arabinose, polysaccharides such as lactose, sucrose, nystose, 1F-fructosyl nystose, stachyose, maltitol, lactitol, lactulose, cellobiose, maltose, cellotriose, maltotriose, raffinose or kestose, gentiobiose, gentiotriose, gentiotetraose, xylotriose and galactosylsucrose may be used. Preferably glucose, fructose, sucrose, kestose, nystose, 1F-fructosyl nystose, stachyose and the like, more preferably sucrose and glucose. As the polysaccharide, oligosaccharides can also be used, and oligosaccharides can be produced by allowing an enzyme such as amylase to act on starch, sucrose, or the like, and examples of oligosaccharides 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 2 or more kinds.

Preferred aliphatic monocarboxylic acids include acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, 2-ethyl-hexane carboxylic 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, fulvic acid, melissic acid, lacceric acid and other saturated fatty acids, undecylenic acid, oleic acid, sorbic acid, linoleic acid, linolenic acid, arachidonic acid, octenoic acid and other unsaturated fatty acids, cyclopentane carboxylic acid, cyclohexane carboxylic acid, cyclooctane carboxylic acid and other alicyclic monocarboxylic acids.

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

In the present embodiment, an ester derivative of sucrose, more specifically, benzoate (DKS co., ltd., product of MONOPET (registered trademark) SB) is used as the sugar ester.

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 repeating unit is about several to 100, and is preferably an aliphatic ester oligomer. This is because the effect as a plasticizer for cellulose acylate is more reliable than that of the aromatic ester oligomer.

The molecular weight of the ester oligomer is preferably in the range of 500 or more and 10000 or less. When the molecular weight is 500 or more, the flexibility (flexibility) and heat sealability of the base material 11 are improved as compared with the case of less than 500, and when the molecular weight is 10000 or less, the compatibility with the cellulose acylate is more reliable as compared with the case of more than 10000. The molecular weight of the ester oligomer is preferably in the range of 700 to 5000, and 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 or a number average molecular weight by GPC (Gel Permeationchromatography), a number average molecular weight measurement method by a terminal functional group amount measurement or an osmotic pressure measurement, a viscosity average molecular weight by a viscosity measurement, or the like. In the present embodiment, the molecular weight is determined by a number average molecular weight measurement method based on measurement of a hydroxyl group or an acid group of an ester as a terminal functional group.

The ester oligomer more preferably has a dicarboxylic acid having a carbon number in the range of 2 or more and 10 or less as a dicarboxylic acid, and more preferably has a diol having a carbon number in the range of 2 or more and 10 or less as a diol. 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 substrate 11 and the water content is more preferable. 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 end-cap the terminal hydroxyl group or acid group of the ester oligomer with a monocarboxylic acid, a monohydric alcohol, or the like. Among them, 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 the masses) was MP. When the substrate 11 contains at least one of an ester derivative of a monosaccharide, an ester derivative of a polysaccharide, and an ester oligomer, the total mass MP of cellulose acylate is preferably in the range of 5 to 30, assuming that the mass is 100. When the total mass MP is 5 or more, the flexibility of the base material 11 is good and/or the laminated film 10 by the laminated film manufacturing apparatus 30 (see fig. 6) is easily manufactured, as compared with the case of less than 5. When the total mass MP is 30 or less, the water content of the substrate 11 is more preferable than the case of more than 30.

As the additive, the substrate 11 may contain, in addition to the plasticizer, an ultraviolet absorber, fine particles as a so-called matting agent that prevents the substrates 11 from adhering to each other, and the like. The additive is preferably an additive whose safety has been confirmed when the material to be packaged is a vegetable or fruit. By adjusting the type and amount of the additive, the water content of the base material 11 can be adjusted, and as a result, the humidity inside the packaged object, for example, during packaging of vegetables and fruits, can be adjusted by the base material 11, so that drying-out of the packaged object can be suppressed.

The propylene polymer (acrylic resin) functions as a regulator of the water content and/or flexibility of the base material 11. Examples of the propylene polymer include methyl acrylate, methyl methacrylate, and copolymers with these acrylic acid or methacrylic acid. When the substrate 11 contains a propylene polymer, the mass of the propylene 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, oligoesters and propylene polymers is described in the following documents. That is, esters of sugars are described in Journal of synthetic organic chemistry, Japan Vol.21(1963) No.1, pages 19 to 27, DKS Co.Ltd. catalog, Japanese patent application laid-open No. 2011-. DKS co, ltd. The ester oligomer includes a content of inhibiting the transfer to Vinyl chloride as an additive to Vinyl chloride, and is described in the homepage of Vinyl Environmental Council, plasticizer industry association data, and the like, and is described in jp 2009-173740 a, including a mixture with cellulose triacetate. Propylene 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.

In the present embodiment, the substrate 11 is formed as a long film. A dope is prepared from the material constituting the substrate 11 as described above, and other additives, solvents, and the like as necessary, and is manufactured by a film forming apparatus (not shown) based on a known solution film forming method. The manufactured long substrate 11 is wound into a roll and proceeds to the next process.

The resin layer 12 is formed of a resin on one surface 11a of the substrate 11, and constitutes the substrate 11 and the laminated film 10. The resin layer 12 functions as a moisture-proof layer, and suppresses release of moisture, which has passed through the substrate 11 having high moisture permeability, to the outside. The resin layer 12 optimizes the bending workability of the laminated film 10 without impairing the workability of the base material 11. By configuring the laminated film 10 as described above, when the base material 11 supplies water to the water vapor present in the inside air of the packaging material and releases the absorbed moisture to the outside of the packaging material in accordance with the humidity or the like outside the packaging material, the resin layer 12 disposed at the outermost layer of the packaging material suppresses the release. Therefore, the resin layer 12 suppresses the release of moisture from the base material 11, thereby suppressing an excessive decrease in the humidity of the space inside the packaging material. Further, even if the packaging material is subjected to bending, the bent portion is not easily broken. In order to more suitably exhibit these effects, when the packaging material is formed of the laminated film 10, the resin layer 12 is preferably disposed on the outer side. The other surface 11b of the base material 11 constitutes the inner side surface of the packaging material. Further, another layer may be formed on the surface 11b, and in this case, the other layer constitutes the inner surface of the packaging material.

Here, the moisture permeation resistance will be explained. The moisture permeability resistance R is calculated as the reciprocal of the moisture permeability, and indicates the difficulty of passing water vapor. Specifically, the moisture permeability is A (g/m)²Day), the moisture permeation resistance R was 1/A. The moisture permeability resistance R per unit thickness of the material is determined by dividing the moisture permeability resistance R by the thickness of the material. For example, when the thickness of the film is d (unit um), the moisture permeation resistance R per unit thickness of the film passes through R/d (unit (m)²Day/g)/μm), i.e., (1/A)/d.

The moisture permeability resistance R of the resin layer 12 can be calculated from the moisture permeability a of each of the laminated film 10 and the substrate 11. This is because the moisture permeability and the moisture permeation resistance are additive in the laminated film. Therefore, when the moisture permeability resistance of the resin layer 12 is R12, the thickness is T12, the moisture permeability resistance of the substrate 11 is R11, the thickness is T11, and the moisture permeability of the laminate film 10 is a10, a10 is 1/(R12+ R11). When the moisture permeation resistance of the laminate film 10 is R10, R10 ═ R11+ R12 is satisfied. Therefore, when the moisture permeability a12 of the resin layer 12 is not measured, the moisture permeability resistance R12 of the resin layer 12 can be calculated from the above calculation formula.

In the resin layer 12, the moisture permeation resistance R12 per 1 μm thickness of the resin layer 12 is preferably 3.0 × 10^-5(m²Day/g)/μm or more and 7.5 × 10-⁴(m²In the range of not more than day/g)/μm, more preferably 3.1 × 10^-5(m²Day/g)/μm or more and 6.0 × 10-⁴(m²In the range of not more than day/g)/μm, more preferably 3.5 × 10^-5(m²Day/g)/μm or more and 2.0 × 10^-4(m²In the range of day/g)/μm or less, the moisture permeation resistance R12 per 1 μm thickness through the resin layer 12 is 3.0 × 10^-5(m²In the range of more than and less than 3.0 × 10^-5(m²The resin layer 12 can more appropriately function as a moisture-proof layer by suppressing the moisture permeability a12 of the resin layer 12 to be smaller than the moisture permeability a11 of the substrate 11 compared to the case of day/g)/μm, and the moisture permeability a10 of the entire laminated film 10 can be set to the specific range described above, the moisture permeation resistance R12 per 1 μm thickness T12 of the resin layer 12 is 7.5 × 10^-4(m²Day/g)/μm or less, and greater than 7.5 × 10^-4(m²The resin layer 12 was less likely to be broken at the time of bending than the case of day/g)/μm. The reason is as follows: when the moisture permeation resistance R12 per 1 μm thickness of the resin layer 12 is high, the thickness of the resin layer 12 is formed to be thin in order to achieve the moisture permeability required for the packaging material, but if the resin layer 12 is too thin, the packaging material is easily broken when it is folded.

The thickness T12 of the resin layer 12 is preferably in the range of 2 μm to 80 μm. Preferably in the range of 4 to 50 μm, more preferably in the range of 10 to 40 μm. When the thickness is 2 μm or more, breakage is less likely to occur when the moisture permeability required for the packaging material is achieved as compared with the case of less than 2 μm, and when the thickness is 80 μm or less, the packaging material becomes thicker and is less likely to appropriately function as a moisture-proof layer as compared with the case of more than 80 μm.

The resin layer 12 is formed of a resin on the surface 11a using the substrate 11 as a support. As a method for forming the resin layer 12, any method can be applied as long as it can be formed on the surface 11a without impairing the function of the substrate 11. Therefore, for example, a resin composition containing a resin forming the resin layer 12 may be formed by coating, or a separate film formed of the resin composition may be bonded to the substrate 11.

In the present embodiment, the resin layer 12 is formed by applying a resin composition prepared for coating (hereinafter referred to as a coating resin composition) to the surface 11a, for example. The resin layer 12 is formed well without the possibility of peeling from the substrate 11 or the like. The resin layer 12 of the present invention needs to have any of a composition composed of an acrylic resin and a cellulose derivative, a silicone elastomer, and a urethane elastomer. A resin composition containing these can be prepared, and the resin layer 12 is formed.

When a film made of a resin composition is formed by laminating the substrate 11 as the resin layer 12, the resin layer 12 can be formed on the surface 11a by a laminating apparatus which is generally used. For example, the surface 11a and the resin layer 12 are bonded to each other with an adhesive or a bonding agent.

The composition comprising an acrylic resin and a cellulose derivative (hereinafter referred to as an acrylic resin mixture), that is, the acrylic resin constituting the mixture with the cellulose resin is not particularly limited as long as it is an acrylic resin capable of being mixed with a cellulose derivative. The acrylic resin is preferred in the following respects: in addition to compatibility with the cellulose derivative as another component of the mixture, other components such as a solvent and, if necessary, other additives can be added as the resin composition, and compatibility with these components is excellent. In some cases, it is preferable to use an acrylic resin having excellent transparency

Specifically, the acrylic resin constituting the resin layer 12 is, for example, methyl acrylate, methyl methacrylate, and a copolymer with these acrylic acid and/or methacrylic acid. In the present specification, the acrylic resin mainly represents acrylic acid, methacrylic acid, and derivatives thereof, and represents polymers such as acrylamide and acrylonitrile. Thus, for example, acrylic resins include methyl acrylate and methyl methacrylate.

Specific examples of the acrylic resin are not particularly limited, and for example, acrylic resins composed of 50 to 99 mass% of methyl acrylate units and 1 to 50 mass% of other monomer units copolymerizable with the methyl acrylate units can be used. Specific examples of the monomer include acrylic esters such as methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, 2-ethyl hexyl acrylate, lauryl acrylate, benzyl acrylate, glycidyl acrylate, and dicyclopentyl acrylate. These monomers may be 1 monomer polymerized alone or 2 or more monomers polymerized in combination. In addition to the above-mentioned acrylate monomers, there may be mentioned resins obtained by using 1 kind or 2 or more kinds in combination of monomers such as aromatic vinyl monomers such as styrene and α -methylstyrene, conjugated dienes such as butadiene and isoprene, macromonomers having a polymerizable unsaturated group such as an acryloyl group at one end of a polymer chain, e.g., polystyrene, polymethyl acrylate, polyethyl acrylate and benzyl acrylate, and phenolic hydroxyl group-containing monomers such as o-hydroxystyrene, m-hydroxystyrene and p-hydroxystyrene. Among the acrylic resins contained in the resin layer 12, acrylic resins obtained by copolymerizing 50 mass% or more of methyl acrylate or methyl methacrylate units are preferable, and resins obtained by copolymerizing ethyl, propyl, n-butyl, or isobutyl esters of acrylic acid or methacrylic acid are more preferable, from the viewpoint of good compatibility with cellulose acylate and excellent transparency.

The molecular weight of the acrylic resin is preferably 5000 to 100 ten thousand, more preferably 1 to 80 ten thousand, and particularly preferably 2 to 50 ten thousand. When the amount is in the range of 5000 to 100 ten thousand, the resin layer is less likely to crack and has good compatibility with the cellulose acylate. The molecular weight of the acrylic resin is a weight average molecular weight (Mw) estimated by a Gel Permeation Chromatography (GPC) method based on a calibration curve prepared using polystyrene standard substances.

As the acrylic resin according to the present invention, commercially available products can be used. Specifically, various homopolymers and copolymers produced from the above-mentioned monomers as raw materials are commercially available, and preferred products can be appropriately selected from them. Examples thereof include Dianal (registered trademark) BR series (Dianal BR-87, BR-77, BR-113, etc., MITSUBISHI RAYONCO., LTD., manufactured by DELPET (registered trademark) 60N, 80N (Asahi Kasei Chemicals Corporation), Sumipex (registered trademark) MH5(Sumitomo Chemical Co., Ltd., manufactured by Ltd.), KT75(Denka Company Limited), etc. In addition, the acrylic resin can be used in 2 or more.

The cellulose derivative constituting the mixture with the acrylic resin is not particularly limited as long as it is a cellulose resin that can be mixed with the acrylic resin. In the present embodiment, the resin layer 12 is formed by applying a coating resin composition 47 (see fig. 6) to the surface 11 a. Therefore, the cellulose derivative is preferable in the following respects: in addition to the compatibility with the acrylic resin as another component of the mixture, other components such as a solvent and other additives may be added as necessary to form a resin composition, and the compatibility with these components is excellent. In some cases, a cellulose derivative having excellent transparency is preferably used.

Specific examples of the cellulose derivative constituting the resin layer 12 are not particularly limited, and examples thereof include cellulose esters, nitrocellulose; cellulose acylate such as acetyl cellulose, diacetyl cellulose, and triacetyl cellulose; cellulose acetate propionate; cellulose acetate butyrate, and the like. The same cellulose acylate as used for the substrate 11 can also be used. Among these cellulose derivatives, a mixed fatty acid ester composed of 2 or more acyl groups can be preferably used for reasons of compatibility with acrylic resins. In this case, the acyl group is preferably an acetyl group or an acyl group having 3 to 4 carbon atoms. When a mixed fatty acid ester is used, the substitution degree of the acetyl group is preferably less than 2.5, and more preferably less than 1.9. On the other hand, the degree of substitution of the acyl group having 3 to 4 carbon atoms is preferably 0.1 to 1.5, more preferably 0.2 to 1.2, and particularly preferably 0.5 to 1.1. Specifically, cellulose acetate butyrate and cellulose acetate propionate are preferably used.

As the cellulose derivative according to the present invention, commercially available products can 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. In addition, more than 2 cellulose derivatives can be used simultaneously.

The acrylic resin mixture constituting the resin layer 12 is not particularly limited as long as the resin layer 12 can be formed on the surface 11 a. In the present embodiment, the resin layer 12 is formed on the surface 11a by applying the coating resin composition 47 (see fig. 6). Therefore, as the acrylic resin mixture constituting the coating resin composition 47 (see fig. 6), TAC and the coating resin composition 47 can be used without limitation as long as TAC and the coating resin composition 47 can be formed. The content ratio of the acrylic resin and the cellulose derivative in the acrylic resin mixture is in the range of 90 to 20, preferably 80 to 30, and more preferably 80 to 40, when the weight of the acrylic resin mixture is 100. When the acrylic resin is 90 or more, the resin layer is less likely to be broken than when the acrylic resin is more than 90. If the acrylic resin is 20 or less, the function of the moisture-proof layer is less likely to be obtained than in the case where the acrylic resin is more than 20.

The acrylic resin mixture can be adjusted by adding additives, adjusting the viscosity by a solvent or the like, as appropriate, according to the coating method of the coating resin composition 47 (see fig. 6) or the like. Preferred examples of the additives include plasticizers, delustering agents, preservatives, and ultraviolet absorbers. The plasticizer can be appropriately selected depending on the function of the moisture-proof layer or the easy-to-crack property of the resin layer. A coating resin composition 47 (see fig. 6) described later was prepared from the acrylic resin mixture and their additives. Examples of the solvent include hydrocarbon solvents such as benzene and toluene; halogenated hydrocarbon solvents such as dichloromethane and chlorobenzene: alcohol solvents such as methanol, ethanol, and isopropanol; ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; ester solvents such as methyl acetate, ethyl acetate, and propyl acetate; ether solvents such as tetrahydrofuran and methyl cellosolve; and the like, and these can be used alone or in combination of 2 or more.

After a coating resin composition 47 (see fig. 6) containing an acrylic resin mixture is applied to the surface 11a, it is cured to form the resin layer 12. The method of curing may be appropriately selected depending on the kind of the acrylic resin and the cellulose derivative contained in the acrylic resin mixture, and curing is usually performed by heating. For example, after coating, the coating can be cured by selecting an appropriate heating method such as heating with a heater, blowing hot air, and placing in an oven, and heating under a predetermined condition. The time for hardening and other conditions can be appropriately adopted depending on the kind of the acrylic resin and the cellulose derivative contained in the acrylic resin mixture.

The silicone elastomer constituting the resin layer 12 is not particularly limited as long as the resin layer 12 can be formed on the surface 11 a. In the present embodiment, the resin layer 12 is formed on the surface 11a by applying the coating resin composition 47 (see fig. 6). Therefore, the silicone elastomer constituting the resin layer 12 can be used without limitation as long as it can be the coating resin composition 47. Among them, the liquid substance is selected from the viewpoint of easy application of the coating liquid, and smoothing of the surface of the resin layer 12 by self-leveling. In addition, the silicone elastomer can be either an addition type or a condensation type, and an addition type silicone elastomer is preferable in that no by-product is generated and reduction due to hardening is small.

The coating resin composition 47 containing a silicone elastomer (see fig. 6) can be adjusted by adding additives, adjusting the viscosity by a solvent, a diluent, or the like, as appropriate depending on the coating method or the like. The silicone elastomer used in the present invention may be a silicone elastomer that is cured at normal temperature, or a silicone elastomer that is cured by heating.

After a coating resin composition 47 (see fig. 6) containing a silicone elastomer is applied to the surface 11a, it is cured to form the resin layer 12. The method of curing may be appropriately selected depending on the type of silicone elastomer contained therein, and the like. For example, if the coating material is a material that hardens at room temperature, the coating material can be hardened by leaving it at room temperature after coating. In the case of a material cured by heating, after coating, it can be cured by heating under predetermined conditions by selecting an appropriate heating method such as heating with a heater, blowing hot air, and putting in an oven. The time for curing and other conditions can be appropriately adopted depending on the resin composition, the silicone elastomer contained therein, and the like.

As the silicone elastomer according to the present invention, commercially available products can be used. Specifically, examples of the addition-type silicone elastomer include "TSE 3033", "TSE 3320" (manufactured by Momentive Performance Materials inc.), and "KE 1212", "KE 1800", and "KE 109" (manufactured by Shin-Etsu Chemical co., ltd.) which are commercially available as two-component thermosetting adhesive liquid silicone rubber. In addition, 2 or more silicone elastomers can be used simultaneously.

The urethane elastomer constituting the resin layer 12 is not particularly limited as long as the resin layer 12 can be formed on the surface 11 a. In the present embodiment, the resin layer 12 is formed on the surface 11a by applying the coating resin composition 47 (see fig. 6). Or by laminating a film made of a resin composition containing a urethane elastomer on the substrate 11, the resin layer 12 is formed on the surface 11 a. Therefore, the urethane elastomer constituting the resin layer 12 can be used without limitation as long as it can be used as the coating resin composition 47 or a film. Among them, liquid, powder, and slurry materials can be selected from the viewpoint of ease of use as a coating solution.

The coating resin composition 47 (see fig. 6) containing the urethane elastomer can be adjusted by adding additives, adjusting the viscosity by a solvent, a diluent, or the like, as appropriate depending on the coating method or the like. The urethane elastomer used in the present invention can be cured by ultraviolet rays or by heating.

After a coating resin composition 47 (see fig. 6) containing a urethane elastomer is applied to the surface 11a, it is cured to form the resin layer 12. The method of curing may be appropriately selected depending on the type of urethane elastomer to be contained. For example, in the case of a material cured by ultraviolet rays, the material can be cured by irradiating ultraviolet rays after coating. In the case of a material cured by heating, after coating, it can be cured by heating under predetermined conditions by selecting an appropriate heating method such as heating with a heater, blowing hot air, and putting in an oven. The time for curing and other conditions can be appropriately adopted depending on the resin composition, the urethane elastomer contained therein, and the like.

As the urethane elastomer according to the present invention, commercially available products can be used. Specifically, ester (adipate) type, ester (lactone) type, ether type, polycarbonate type, aliphatic non-yellowing type, and the like can be used as the two-component curable polyurethane and thermoplastic polyurethane elastomer. Commercially available products include PANDEX (registered trademark) GW series "GW-3670/HX-770" (manufactured by DIC CORPORATION), Elastollan (registered trademark) C80A, C85A, C90A, C95A, C64D, 1180A, 1185A, 1190A, 1195A, 1164D, ET, ET880, ET885, ET890, ET858D, ET860D, ET864D, NY585, NY90A, NY1197A (manufactured by BASFJapan Ltd.), PANDEX (registered trademark) T-5105, T-5201, T-5265, T8175, T8180, T8185, T8190, T8195, T6370, A, A7A, 588, K588U 62-685, K-62, and Polyamfdep 2 (registered trademark) WO 7000, 2000, polyFdDP 6326, and polyFdP 2. In addition, the urethane elastomer can be used in 2 or more kinds at the same time.

The shape of the packaging material is not limited as long as the packaging material is composed of the laminate film 10, and in order to sufficiently exhibit the function of adjusting the amount of water vapor in the space inside the packaging material, the configuration is preferably such that the resin layer 12 of the laminate film 10 is disposed outside the package. This makes it possible to more effectively exhibit the effect of suppressing, by the resin layer 12: after the base material 11 absorbs the water vapor present in the space inside the packaging material, the supplied moisture is released to the outside of the packaging material in accordance with the environment outside the packaging material.

The shape of the packaging material is not particularly limited as long as it is formed of the laminate film 10 and can package the object to be packaged. For example, the film-shaped packaging material alone may be packaged so that the object to be packaged is wrapped with the laminated film 10. The packaging material can be formed into other shapes such as a bag shape, a box shape, and a cylindrical shape by processing the laminated film 10. The processing method is not particularly limited as long as the laminated film 10 can be processed into a shape of a packaging material.

For example, as shown in fig. 2, the laminated film 10 may be formed into a bag-shaped packaging material 14. The packaging material 14 is prepared by cutting the laminated film 10 into 2 films in a rectangular sheet shape having a long side of 300mm and a short side of 220mm, disposing the resin layer 12 on the outer side, overlapping the films, and heat-sealing and bonding three of 2 long sides and 1 short side to form the heat-sealed portion 16, thereby forming a bag-shaped packaging material. The width W14 of the packaging material 14 was 220mm and the height H14 was 300mm, with the shorter side not heat-sealed being the opening 18, the shorter side being the width, and the longer side being the height.

The object to be packaged is placed through the opening 18, and is thereby packaged. When the amount of water vapor in the space inside the packaging material 14 is appropriately maintained and adjusted, the opening 18 is preferably sealed. The sealing method is not particularly limited as long as it can seal the opening 18, and tape sealing, heat sealing, and the like are used. In the packaging material 14, the base materials 11 are disposed on the inner side and the resin layer 12 is disposed on the outer side, and therefore the base materials 11 are heat-sealed to each other. As described above, the substrate 11 is configured to contain cellulose acylate, and therefore, has good heat sealability.

For example, as shown in fig. 3, the laminated film 10 may be a tubular packaging material 20 having a tubular shape. The wrapping material 20 is formed from a wrapping material roll 24 (formed from a long strip of laminated film 10 having a width of 310 mm) as shown in figure 4. The laminated film 10 was laminated with adhesive portions 22 each having a width direction end portion of 10mm, and was then wound into a roll to form a packaging material roll 24. The width W22 of the overlapping portion of the glue application portion 22 is 10 mm. Therefore, the width-directional length W24 of the packaging material roll 24 is 150 mm. The packaging material 20 is obtained by cutting a predetermined length from a packaging material roll 24. When the wrapping material 20 is formed into a substantially cylindrical shape, the width W20 of the wrapping material 20 is about 96 mm.

The opening 18 at 2 of the packaging material 20 may be closed or not. When the amount of water vapor in the space inside the packaging material 20 is appropriately maintained and adjusted, it is preferable that the 2-position opening 18 is sealed. The method of sealing can be the same as for the packaging material 14. Also, a cover and/or a base formed of other components may be provided. When both ends of the laminated film 10 in the width direction are overlapped and bonded, the substrate 11 is placed on the inside and the resin layer 12 is placed on the outside. Therefore, the inner side of the packaging material 20 is the base material 11, and the outer side is the resin layer 12.

The widthwise end of the web of packaging material 24 is formed into a folded portion 26. The folded portion 26 is a portion of the laminated film 10 that is folded with the resin layer 12 disposed on the outside, but the folded portion of the packaging material of the present invention is not easily broken. Further, the packaging material is preferably provided with a folded portion because the packaging material can be formed into various shapes according to the objects to be packaged.

For example, as shown in fig. 5, the laminated film 10 may be formed into a box-shaped packaging material 27 having a box shape. The packaging material 27 is formed into a rectangular parallelepiped shape having a rectangular bottom portion B27 by folding the laminated film 10 at one opening portion of the cylindrical packaging material, then bonding the film with an adhesive, and processing the film into a bottom gusset shape. In addition, illustration of the gusset is omitted. The other opening is opened as an opening 18. The wrapping material 27 has a glue application portion 22 and an opening portion 18. In rectangular bottom B27, width W27 of packaging material 27 as the long side is 150mm, width D27 of the bottom as the short side is 90mm, and height H27 of opening 18 provided on the upper surface is 280 mm. Therefore, the width of the cylindrical packaging material before processing into a box shape was 480 mm.

In the cylindrical packaging material, when both ends of the laminated film 10 in the width direction are overlapped and bonded, the base 11 is located inside and the resin layer 12 is located outside, and therefore, in the packaging material 27, the inside of the packaging material is located as the base 11 and the outside of the packaging material is located as the resin layer 12. The packing material 27 has a folded portion 26. As described above, the folded portion 26 is not easily broken, and can be formed into a packaging material having various shapes according to the object to be packaged.

In the present embodiment, as a method for forming the resin layer 12 on the surface 11a, a method of applying a resin composition for coating is adopted as described above, and the multilayer film can be produced by a multilayer film production apparatus. The laminated film manufacturing apparatus 30 shown in fig. 6 is an example of an apparatus for continuously manufacturing the laminated film 10. The laminated film manufacturing apparatus 30 includes a feeder 31, a resin layer forming unit 32, a drying device 33, and a winder 34 in this order from the upstream side in the conveyance direction of the long substrate 11. Further, a roller 44 is provided. Although a plurality of rollers 44 are provided, only one roller is illustrated in fig. 6. The roller 44 supports the substrate 11 from below on the circumferential surface, and rotates around the rotation axis, thereby conveying the substrate 11. In this example, the substrate 11 is manufactured by a film forming apparatus (not shown) based on a known solution film forming method. As described above, the substrate 11 contains cellulose acylate as an essential component, and is TAC in this embodiment.

The feeder 31 continuously feeds the long substrate 11. The base material 11 is set in the feeder 31 in a state of being wound around the winding core 38 in a roll shape, and the base material 11 is continuously fed by rotating the winding core 38.

The resin layer forming unit 32 is for continuously forming the resin layer 12 on the surface 11 a. The resin layer forming unit 32 includes an application device 41 and an infrared heater 42.

The coating device 41 is used to coat the surface 11a with a coating resin composition 47 for forming the resin layer 12. In fig. 6, the coating resin composition 47 is described as a "composition". In the coating device 41, the supplied coating resin composition 47 is continuously discharged from the outlet 41a facing the surface 11 a. The coating device 41 continuously flows out the coating resin composition 47 to the substrate 11 being conveyed, whereby the coating resin composition 47 is continuously applied to the surface 11 a.

The infrared heater 42 is used to heat the substrate 11 to cure the coating resin composition 47. The infrared heater 42 is provided in a state where an emission surface from which infrared rays are emitted faces the substrate 11 being conveyed. The infrared heater 42 may be disposed so as to face the surface 11a on which the coating film 48 formed of the coating resin composition 47 is formed, or may be disposed so as to face the surface 11b, which is the film surface opposite to the surface 11a, as in the present embodiment shown in fig. 6.

Instead of the infrared heater 42 (or in addition to the infrared heater 42), a blowing type blower for blowing the heated gas to the substrate 11, a chamber type blower for supplying the heated gas to a transfer passage surrounding the substrate 11 through a chamber, or the like may be used. When a resin composition cured by ultraviolet light is used, the ultraviolet irradiation device is disposed in a state of facing the surface 11 a.

The resin layer 12 is formed on the substrate 11 passing through the infrared heater 42, and the substrate 11 is introduced into the drying device 33 to be dried. In the present embodiment, a chamber type drying apparatus is used in which a transfer path is surrounded by a chamber and heated gas is supplied to the chamber, but the drying apparatus is not particularly limited. By this drying, the solvent contained is evaporated, thereby obtaining a long laminated film 10. The laminated film 10 is introduced into the winder 34, and wound around the provided winding core 49 in a roll shape.

The packaging material of the present invention is configured as described above, and therefore, even if the packaged body is stored for a long period of time after the packaged object is placed in the packaging material and the packaged body is hermetically sealed by refrigeration, the packaged object is prevented from being dried without dew condensation occurring on the inside of the packaging material, and deformation after water absorption is reduced. Further, the packaging material is less likely to be damaged by bending. Therefore, according to the packaging material of the present invention, for example, when the packaged object is vegetables and fruits, the vegetables and fruits can be preserved for a long period of time while maintaining their freshness. And, it is suitable for packaging the packaged article that preferably suppresses drying of the packaged article. Therefore, preferable objects to be packaged include, in addition to vegetables and fruits, plants including flowers, culture solutions for cultured cells, and foods.

As shown in fig. 7, a package 28, which is an example of a method of using the packaging material of the present invention, is a sealed package in which broccoli, which is a vegetable, is put into the packaging material 14 as an object to be packed 25, the upper portion of the packaging material 14 in fig. 7 is folded, and the opening 18 is closed and sealed with an adhesive tape 29. Since the folded portion 26 of the packaging material 14 is not easily broken, a sealed package can be formed by an easy method of folding and sealing with the tape 29. Further, a method such as heat sealing may be used to close the opening 18.

For example, since vegetables and fruits maintain physiological actions such as moisture release and respiration, when the packaging materials 14, 20, and 27 are used, the effects of suppressing dew condensation and adjusting the humidity inside the packaging material by the moisture contained in the laminated film 10 can be reliably obtained by the actions of the base material 11 and the resin layer 12. Examples of such vegetables and fruits include broccoli such as broccoli and cauliflower, leafy vegetables such as spinach and komatsuna, fruit vegetables such as green pepper, eggplant, tomato, cucumber, strawberry and green soy bean, fruits such as banana, grape, apple, pear and orange, root vegetables such as yam and burdock, mushrooms such as shiitake and hypsizygus marmoreus, and cut flowers such as chrysanthemum and lily. Among them, the packaging material can be preferably used for, in particular, cauliflower, leaf vegetables, fruit vegetables, mushrooms, cut flowers, and the like, because moisture is released in a large amount and condensation during long-term storage and distribution in refrigeration is remarkable.

The packaging materials 14, 20, 27 are suppressed in dew condensation and discoloration during storage at room temperature, and are prevented from dew condensation and discoloration during refrigeration and can be stored for a long period of time. Dew condensation is suppressed and thus mold is also suppressed. The storage at room temperature means a range of 10 ℃ to 30 ℃ inclusive, and the storage at a low temperature means a range of 0 ℃ to 10 ℃ inclusive. The packaging materials 14, 20, and 27 can sufficiently prevent dew condensation during refrigeration, and therefore, more preferable effects can be obtained in the refrigerated storage.

In order to maintain freshness of the vegetables and fruits, it is preferable to store the vegetables and fruits under refrigeration, and the temperature during storage is preferably in the range of 0 ℃ to 10 ℃. In cold storage, air is generally cooled by a heat exchanger, and at this time, moisture in the air is removed by the heat exchanger, and the humidity in the refrigerator tends to decrease. On the other hand, since the saturated water vapor amount in the air is smaller than that at normal temperature at the temperature of cold preservation, condensation occurs when humidification, packaging of vegetables and fruits, or the like is performed during cold preservation. In the case of using a conventional packaging material for packaging or packaging with a microporous MA (Modified atmosphere), moisture permeability of the packaging material is low, and thus moisture is released from vegetables and fruits to cause condensation on the inside of the packaging material. The occurrence of dew condensation causes, for example, the occurrence and proliferation of mold, the suppression of respiration of vegetables and fruits due to dew condensation on the surface of vegetables and fruits, and the decrease in MA packaging effect due to clogging of fine pores. The packing materials 14, 20, and 27 absorb and release moisture in accordance with a change in humidity inside the packing material in accordance with the equilibrium moisture content of the base material 11, and therefore dew condensation is prevented inside the packing material. The resin layer 12 prevents excessive moisture release and maintains a humidity at which the drying of the vegetables and fruits is suppressed.

The packaging materials 14, 20, and 27 can be used in both of the sealed packaging and the open packaging, but when packaging is performed by the sealed packaging, the effect of suppressing dew condensation can be more remarkably improved, and when the object to be packaged is a vegetable or fruit, the effect of suppressing discoloration of the vegetable or fruit, and the effect of suppressing mold can be more remarkably confirmed. The inhibition of mold means inhibition of the generation and growth of mold. In addition, sealed packaging is more preferable than open packaging in terms of suppressing contamination of the vegetables and fruits by bacteria, dust, and the like and drying of the vegetables and fruits. As the sealed package, for example, a sealed package is provided in which vegetables and fruits are put in the packaging material 14 and the opening 18 is closed with an adhesive tape, that is, a sealed package is provided. Further, the open package includes a so-called handkerchief package in which an object is placed on a rectangular sheet-like packing material and 4 corner ends are folded and twisted at the upper portion as wrapped with a handkerchief. The open package also includes a package formed by a packaging material having a plurality of micro holes penetrating through the packaging material in the thickness direction. When the laminated film 10 is formed into various packaging materials, the formation by heat sealing is not limited, and the laminated film may be formed using an adhesive or an adhesive.

[ 2 nd embodiment ]

In the present embodiment, as shown in fig. 8, the laminated film 50 includes a substrate 11 and a resin layer 12, and has a saponification layer 13 on a surface 11 b. The saponified layer 13 is a layer formed on the side of the face 11b by the saponification treatment, and is a layer containing saponified cellulose acylate. The laminated film 50 of the present embodiment is the same as that of embodiment 1 except that it has a saponification layer 13. Therefore, the description of the same components as those of embodiment 1 will be omitted. In fig. 8, the same reference numerals as those in fig. 1 to 7 denote the same components as those in embodiment 1, and therefore, the description thereof will be omitted.

The saponified layer 13 is made of saponified cellulose acylate, and in the present embodiment, saponified TAC is formed by saponification that is an alkali hydrolysis reaction of cellulose ester. The saponification treatment reduces the number of acyl groups contained in the cellulose acylate by converting the acyl groups into hydroxyl groups through substitution reaction. The saponified layer 13 of cellulose acylate having hydroxyl groups has hydrophilicity. Therefore, by providing the saponification layer 13 on the surface 11b and disposing the saponification layer 13 inside the packaging material, the inside of the packaging material has hydrophilicity. Accordingly, even if water vapor that cannot be absorbed by the base material 11 is generated in the space inside the packaging material, for example, the moisture content due to the water vapor becomes a hydrophilic film because the surface of the saponification layer 13 has hydrophilicity, and condensation does not easily occur inside the packaging material. As described above, the saponification layer 13 is preferable because dew condensation is highly prevented.

The thickness T13 of the saponified layer is preferably in the range of 1 to 6 μm, more preferably in the range of 2 to 5 μm. In the present embodiment, the thickness is set to 2 μm. The thickness T13 is preferably 1 μm or more because it is superior to the case of less than 1 μm in initial antifogging property, i.e., the function of preventing instantaneous condensation, and condensation is less likely to occur inside the packaging material, for example, when the package is put into a refrigerator. On the other hand, a thickness of 6 μm or less is preferable because the long-term antifogging property, that is, the function of preventing dew condensation for a long time is superior to that in the case of more than 6 μm, and the effect of preventing dew condensation inside the packaging material is maintained for a long time, and therefore, dew condensation is not likely to occur. In the present embodiment, the thickness T13 is determined by the following method. A sample taken from the substrate 11 was immersed in methylene chloride for 24 hours. The sample remaining after dissolution by immersion was dried, and the thickness of the dried sample was measured 3 times. The average of the 3 measured values was defined as thickness T13.

In the present embodiment, the saponified layer 13 can be formed by a laminated film forming apparatus. The laminated film forming apparatus 51 shown in fig. 9 is a part of the laminated film 50, and is an example of an apparatus for continuously producing a laminated film material 54 composed of the base material 11 and the saponified layer 13. The laminated film 50 includes a substrate 11, a resin layer 12, and a saponified layer 13, and a laminated film forming apparatus 51 shown in fig. 9 forms the saponified layer 13 on the substrate 11. Therefore, the laminated film 50 is manufactured by manufacturing the laminated film material 54 composed of the base material 11 and the saponified layer 13 by the laminated film forming apparatus 51, and then forming the resin layer 12 on the laminated film material 54. Specifically, the laminated film material 54 is produced by the laminated film forming apparatus 51, and is fed to the laminated film producing apparatus 30 (refer to fig. 6) after being wound around the winding core 62. In the laminated film manufacturing apparatus 30 (see fig. 6), the laminated film 50 is manufactured by providing the laminated film material 54 instead of the base material 11 and forming the resin layer 12 on the surface 11a of the laminated film material 54. The order of forming the resin layer 12 and the saponified layer 13 on the substrate 11 is not limited to this. For example, the saponification layer 13 may be formed after the resin layer 12 is formed on the substrate 11, and the resin layer 12 and the saponification layer 13 may be formed simultaneously on the substrate 11.

The laminated film forming apparatus 51 includes a feeder 31, a saponification unit 52, a drying device 33, and a winder 34 in this order from the upstream side in the conveyance direction of the long substrate 11. Further, a roller 44 is provided. Although a plurality of rollers 44 are provided, only two rollers are illustrated in fig. 9. The roller 44 supports the substrate 11 or the laminated film material 54 from below on the circumferential surface, and rotates around a rotation axis, thereby conveying the substrate 11 or the laminated film material 54. The substrate 11 constitutes a laminated film 50, and in this example, is manufactured by a film forming apparatus (not shown) based on a known solution film forming method. As described above, the substrate 11 contains cellulose acylate as an essential component, and is TAC in this embodiment.

The feeder 31 continuously feeds the long substrate 11. The base material 11 is set in the feeder 31 in a state of being wound around the winding core 56 in a roll shape, and the base material 11 is continuously fed by rotating the winding core 56.

The saponification unit 52 is used to form a laminated film material 54 by continuously saponifying the substrate 11. The saponification unit 52 includes an application device 41, an infrared heater 42, and a cleaning device 43.

The application device 41 is used to apply the saponification liquid 58 to the surface 11 b. In the coating device 41, the supplied saponification liquid 58 is continuously discharged from the outlet 41a facing the surface 11 b. The application device 41 continuously discharges the saponification liquid 58 to the substrate 11 being conveyed, whereby the saponification liquid 58 is continuously applied to the surface 11 b. As a method of the saponification treatment, a method of applying the saponification liquid 58 by coating, a method of applying by dipping, and the like can be cited as well as the embodiment.

The saponification solution 58 is used for saponifying the surface 11b side of the base material 11 to form a saponified layer 13 (see fig. 8), and contains alkali and water. In the present embodiment, the base is potassium hydroxide (KOH), but is not limited thereto, and sodium hydroxide (NaOH) may be used instead of KOH. In this example, the saponification liquid 58 contains an alcohol having 2 to 3 carbon atoms in addition to the alkali and water, and the application device 41 applies the saponification liquid 58 to the surface 11 b. The alcohol serves to facilitate penetration of the base into the substrate 11. As the alcohol having 2 to 3 carbon atoms, isopropyl alcohol is particularly preferable, and in the present embodiment, isopropyl alcohol is also used.

In this example, the alcohol is applied by saponification liquid application, but the method is not limited to this, and for example, a method of sequentially applying an alcohol and an aqueous alkali solution may be used. In this case, it is more preferable to apply the saponification liquid after applying the alcohol.

In every 1m of the face 11b²An area of at least 17g, i.e. in an amount of 17g/m²The alcohol was applied to the surface 11b at the above-mentioned application amount. The amount of alcohol to be applied is preferably 17g/m²Above and 39.6g/m²More preferably in the range of 22g/m²Above and 39.6g/m²More preferably, it is in the range of 33.4g/m²Above and 39.6g/m²Within the following ranges.

In every 1m of the face 11b²An area of at least 0.3g, i.e. in an amount of 0.3g/m²The alkali is applied to the surface 11b at the above-mentioned application amount. Thereby, the alkali reliably and quickly penetrates into the base material 11. The amount of the base to be applied is preferably 0.3g/m²Above and 1.3g/m²More preferably in the range of 0.6g/m²Above and 1.3g/m²The following rangeIn the enclosure, it is further preferably 0.7g/m²Above and 1.3g/m²Within the following ranges.

The infrared heater 42 is used to heat the substrate 11 and maintain the substrate within a predetermined temperature range for a predetermined time. The infrared heater 42 is provided in a state where an emission surface from which infrared rays are emitted faces the substrate 11 being conveyed. The infrared heater 42 may be disposed so as to face the surface 11b on which the coating film 60 formed of the saponification liquid 58 is formed, but in consideration of the fact that the alkali can more reliably and efficiently permeate from the surface 11b side, it is preferably disposed so as to face the surface 11a, which is the film surface on the side opposite to the surface 11b, as in the present embodiment shown in fig. 9.

Instead of the infrared heater 42 (or in addition to the infrared heater 42), a blowing type blower for blowing the heated gas to the substrate 11, a chamber type blower for supplying the heated gas to a transfer passage surrounding the substrate 11 through a chamber, or the like may be used.

If the thickness T13 (see fig. 8) of saponified layer 13 is too small, initial antifogging properties are hard to develop, and if it is too large, long-term antifogging properties are hard to develop. Therefore, in order to achieve both the initial antifogging property and the long-term antifogging property, the surface 11b is held at a temperature of 40 ℃ to 80 ℃ for a time of 20 seconds to 120 seconds by heating with the infrared heater 42. By keeping at 40 ℃ or higher, saponification proceeds rapidly as compared with the case of lower than 40 ℃, and since saponification layer 13 having a larger thickness T13 is formed, initial antifogging property is reliably exhibited. By keeping the temperature at 80 ℃ or lower, the saponification layer 13 is reliably formed by reliably suppressing the evaporation of alcohol as compared with the case of higher than 80 ℃, and the saponification layer 13 having a small thickness T13 is formed, so that the long-term antifogging property is reliably exhibited. The holding temperature is more preferably in the range of 40 ℃ to 70 ℃, and still more preferably in the range of 50 ℃ to 70 ℃.

The time for maintaining the temperature within the above temperature range is set to 20 seconds or more and 120 seconds or less. By setting to 20 seconds or more, saponification proceeds rapidly as compared with the case of shorter than 20 seconds, and since saponification layer 13 having larger thickness T13 (refer to fig. 8) is formed, initial antifogging property is reliably exhibited. By setting the time to 120 seconds or less, the thickness T13 (see fig. 8) of the saponified layer 13 is formed thinner than that in the case of being longer than 120 seconds, and therefore, long-term antifogging properties are reliably exhibited. The time for holding in the above temperature range is more preferably 30 seconds or more and 100 seconds or less, and still more preferably 30 seconds or more and 50 seconds or less.

The cleaning device 43 is used to stop saponification by cleaning the substrate 11. The cleaning device 43 includes a spray type cleaning machine that sprays water to the surface 11b side on which the coating film 60 is formed. The alkali is rapidly removed from the substrate 11 by spraying water.

The saponified layer 13 is formed on the base material 11 that has passed through the cleaning device 43, and the base material 11 is introduced into the drying device 33 and dried. In the present embodiment, a chamber type drying apparatus is used in which a transfer path is surrounded by a chamber and heated gas is supplied to the chamber, but the drying apparatus is not particularly limited. By this drying, the contained water is evaporated, thereby obtaining a long laminated film material 54. The laminated film material 54 is introduced into the winder 34, and wound around the provided winding core 62 in a roll shape.

As described above, the laminated film material 54 wound around the winding core 62 is sent to the next step, whereby the laminated film 50 is manufactured. That is, in the laminated film manufacturing apparatus 30 (see fig. 6), the core 62 is provided instead of the core 38, the laminated film material 54 is supplied, and the resin layer 12 is formed on the surface 11 a.

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