Packaging film and packaging material

Abstract

To provide a film for a package and a package which have oxygen barrier property and water vapor barrier property for repeated uses, have reduced odor and can be easily recycled.SOLUTION: There is provided a film for a package 1 which comprises a base material 10 in which a vapor deposition layer 14 having a specific thickness is formed on one surface of a base layer 12 composed of a biaxially oriented polypropylene film, a sealant material 20 which is positioned on one surface of the base material 10 and is composed of a non-stretched polypropylene film and an adhesive layer 30 which is positioned between the base material 10 and the sealant material 20 and contains a specific amount of an oxygen absorber, wherein the calorie ratio of the endothermic peak of β'-crystal group derived from β-crystal to the total calorie of the endothermic peak of the base material 10 measured by heat-flux differential scanning calorimetry is 10% or less.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a film for packaging and a packaging material. [Background technology]

[0002] Gas barrier films that have the function of blocking oxygen and water vapor are known and are widely used as packaging materials. It is known that ultraviolet rays and oxygen can cause the quality of contents such as food and medicine to deteriorate. For example, fats and oils are strongly affected by ultraviolet rays, and oxidative deterioration progresses. Many natural pigments are unstable when exposed to ultraviolet rays, and there is a risk of discoloration.

[0003] To address these problems, for example, Patent Document 1 proposes a barrier laminate film that includes a gas barrier coating film provided on an unstretched polyolefin resin film and an aluminum vapor-deposited layer provided on the gas barrier coating film. The invention of Patent Document 1 has oxygen barrier properties, water vapor barrier properties, light-shielding properties, and gloss properties equivalent to those of aluminum vapor-deposited polyethylene terephthalate (aluminum vapor-deposited PET), and is improved in adhesion and heat sealability. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2013-22918 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the invention of Patent Document 1 has a problem in that recycling is difficult because various functions are imparted by combining a plurality of materials with different properties. Packaging films are also required to reduce odors caused by residual solvents, and are also required to maintain oxygen barrier properties and water vapor barrier properties even when used repeatedly.

[0006] The present invention has been made in consideration of the above circumstances, and aims to provide a packaging film and a packaging material that have oxygen barrier properties and water vapor barrier properties even when used repeatedly, have reduced odor, and can be easily recycled. [Means for solving the problem]

[0007] It is known that the crystal structure of polypropylene includes α crystals (also called monoclinic), β crystals (also called hexagonal), and γ crystals (also called triclinic). It is known that β crystals include β' crystals (β prime crystals, also called pseudohexagonal crystals) derived from β crystals. As a result of extensive research, the inventors discovered that the β' crystal group derived from β crystals (β' crystals and crystals similar to β' crystals) is easily able to absorb organic solvents contained in adhesives, such as ethyl acetate and methyl ethyl ketone (MEK), and that by suppressing the production of the β' crystal group, the odor caused by residual solvents can be reduced.

[0008] That is, the packaging film of the present invention has the following configuration. [1] A substrate having a deposition layer formed on one side of a base layer made of a biaxially oriented polypropylene film; A sealant material located on one surface of the base material and made of a non-oriented polypropylene film; an adhesive layer located between the substrate and the sealant material; the deposition layer faces the sealant material, The thickness of the deposition layer is 20 to 100 nm; the adhesive layer is a cured product of an isocyanate-based adhesive containing a polyester polyol having a carbon-carbon double bond and a compound having an isocyanate group, The isocyanate-based adhesive contains an oxygen absorber, The content of the oxygen absorber is 1% by mass or more based on the total mass of the isocyanate-based adhesive, A packaging film, in which the ratio of the heat quantity of the endothermic peak of the β' crystal group derived from the β crystal to the total heat quantity of the endothermic peak of the substrate measured with a heat flux differential scanning calorimeter is 10% or less. [2] The film for packaging according to [1], wherein the ratio of the heat quantity of the endothermic peak of α crystals to the total heat quantity of the endothermic peak of the substrate measured with a heat flux differential scanning calorimeter is 80% or more. [3] The film for packaging according to [1] or [2], wherein the oxygen absorber is at least one selected from the group consisting of a conjugated diene polymer cyclized product, a transition metal salt of an organic acid, tetrahydrophthalic acid, and a derivative of tetrahydrophthalic acid. [4] A packaging material produced using the packaging film according to any one of [1] to [3]. Effect of the Invention

[0009] The packaging film of the present invention has oxygen barrier properties and water vapor barrier properties against repeated use, reduces odors, and can be easily recycled. [Brief description of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view of a packaging film according to one embodiment of the present invention. [Diagram 2] 2 is an example of a DSC curve of a substrate according to an embodiment of the present invention. [Diagram 3] 4 is an example of a DSC curve of a packaging film according to a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The packaging film of the present invention comprises a substrate having a vapor deposition layer formed on one side of a base layer made of a biaxially oriented polypropylene film, and a sealant material made of a non-oriented polypropylene film and positioned on one side of the substrate. In the packaging film of the present invention, the resin of the substrate and the resin of the sealant are the same type (polypropylene), so that when the packaging film of the present invention is collected, it is not necessary to collect the substrate and the sealant separately, and the film can be easily recycled.

[0012] <Packaging film> DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A packaging film according to one embodiment of the present invention will be described with reference to the drawings. 1 is formed by laminating a substrate 10, an adhesive layer 30, and a sealant 20 in this order. That is, the film 1 for packaging includes the substrate 10, the sealant 20 located on one side of the substrate 10, and the adhesive layer 30 located between the substrate 10 and the sealant 20. The substrate 10 is formed by forming a deposition layer 14 on one side of a base layer 12. The surface of the deposition layer 14 faces the surface of the sealant 20.

[0013] The oxygen permeability of the packaging film 1 is 4.0 mL / (m 2 ·day) or less is preferable, and 2.0mL / (m 2 ·day) or less is more preferable, and 1.0mL / (m 2 ·day) or less is even more preferable. When the oxygen permeability of the film 1 for packaging is the above upper limit or less, the film 1 for packaging has excellent oxygen barrier properties. The smaller the oxygen permeability of the film 1 for packaging, the more preferable it is. The lower limit of the oxygen permeability is 0 mL / (m 2 ·day) is preferred. The oxygen permeability of the packaging film 1 can be measured in accordance with the test method for oxygen gas permeability using an electrolytic sensor method described in Appendix A of JIS K7126-2:2006. The oxygen permeability of the packaging film 1 can be adjusted by the material and thickness of the base layer 12, the material and thickness of the vapor deposition layer 14, the material and thickness of the sealant material 20, the type and content of the oxygen absorbent, or a combination of these.

[0014] The oxygen permeability of the packaging film 1 after the accelerated deterioration test was 6.0 mL / (m 2 ·day) or less is preferable, and 2.0mL / (m 2·day) or less is more preferable, and 1.0mL / (m 2 ·day) or less is even more preferable. When the oxygen transmission rate of the film for packaging 1 after the accelerated deterioration test is the above upper limit or less, the film has excellent oxygen barrier properties for repeated use. The lower the oxygen transmission rate of the film for packaging 1 after the accelerated deterioration test, the more preferable it is, and the lower limit of the oxygen transmission rate after the accelerated deterioration test is 0 mL / (m 2 ·day) is preferred. The oxygen permeability of the packaging film 1 after the accelerated deterioration test can be measured in the same manner as the oxygen permeability (initial) described above. The oxygen permeability of the packaging film 1 after the accelerated deterioration test can be adjusted by the material and thickness of the base layer 12, the material and thickness of the vapor deposition layer 14, the material and thickness of the sealant material 20, the type and content of the oxygen absorber, and combinations of these.

[0015] An example of an accelerated deterioration test for the packaging film 1 is the Gelbo test. The Gelbo test is a test method for evaluating the pinhole resistance of packaging films, in which the film is repeatedly locally bent and evaluated for fatigue failure caused by the bending. Details of the Gelbo test are described in the Examples.

[0016] The residual solvent content of the packaging film 1 is 5.0 mg / m 2 Less than 2.0 mg / m is preferred. 2 Less than 1.0 mg / m is more preferable. 2 It is more preferable that the content of the residual solvent in the packaging film 1 is equal to or less than the above upper limit, the odor can be further reduced. The amount of residual solvent in the packaging film 1 can be measured, for example, by using a capillary gas chromatograph. The amount of residual solvent in the packaging film 1 can be adjusted by the ratio of the heat quantity of the endothermic peak of the β' crystal group to the total heat quantity of the endothermic peak of the substrate 10 described later.

[0017] The thickness T1 of the film for packaging 1 is not particularly limited, but is, for example, preferably 35 to 250 μm, more preferably 40 to 200 μm, and even more preferably 50 to 150 μm. When the thickness T1 is equal to or greater than the above lower limit, the strength of the film for packaging 1 is increased. When the thickness T1 is equal to or less than the above upper limit, the flexibility of the film for packaging 1 is increased, making it easier to handle. The thickness T1 of the packaging film 1 can be measured, for example, by a thickness gauge.

[0018] <Base material> The substrate 10 is formed by forming a vapor-deposited layer 14 on one side of a base layer 12 made of a biaxially oriented polypropylene film. In other words, the substrate 10 is a vapor-deposited biaxially oriented polypropylene film. The surface of the vapor-deposited layer 14 of the substrate 10 faces one side of the sealant material 20. By using a vapor-deposited biaxially stretched polypropylene film as the substrate 10, the film for packaging 1 has excellent oxygen barrier properties and water vapor barrier properties even when used repeatedly. This is thought to be because by providing a vapor-deposited layer that is difficult to stretch on a biaxially oriented polypropylene film that is also difficult to stretch, the vapor-deposited layer is less likely to be destroyed by friction or bending, and peeling between the vapor-deposited layer and the polypropylene film is less likely to occur, compared to when the vapor-deposited layer is provided on a non-oriented polypropylene film that is more likely to stretch.

[0019] The tensile modulus of the substrate 10 in the MD direction (the extrusion direction when the film is produced) is preferably 1.8 GPa or more, more preferably 1.9 GPa or more, and even more preferably 2.0 GPa or more. When the tensile modulus of the substrate 10 in the MD direction is equal to or more than the lower limit, the film 1 for packaging has excellent water vapor barrier properties. The upper limit of the tensile modulus of the substrate 10 in the MD direction is not particularly limited, but is, for example, 5.0 GPa. The tensile modulus of elasticity in the MD direction of the substrate 10 can be measured in accordance with the test method described in JIS K7127:1999. The tensile modulus of elasticity in the MD direction of the substrate 10 can be adjusted by the material and thickness of the substrate 10, molding conditions (molding temperature, cooling time, extrusion speed), and the like.

[0020] The tensile modulus of the substrate 10 in the TD direction (direction perpendicular to the MD direction) is preferably 3.6 GPa or more, more preferably 3.7 GPa or more, and even more preferably 3.8 GPa or more. When the tensile modulus of the substrate 10 in the TD direction is equal to or more than the lower limit, the film 1 for packaging has excellent water vapor barrier properties. The upper limit of the tensile modulus of the substrate 10 in the TD direction is not particularly limited, but is, for example, 7.0 GPa. The tensile modulus of elasticity in the TD direction of the substrate 10 can be measured in the same manner as the tensile modulus of elasticity in the MD direction of the substrate 10. The tensile modulus of elasticity in the TD direction of the substrate 10 can be adjusted by the material and thickness of the substrate 10, molding conditions (molding temperature, cooling time, extrusion speed), and the like.

[0021] The water vapor permeability of the substrate 10 is 4.0 g / (m 2 ·day) or less is preferable, and 2.0g / (m 2 ·day) or less is more preferable, and 1.0g / (m 2 ·day) or less is even more preferable. When the water vapor permeability of the substrate 10 is equal to or less than the above upper limit, the film 1 for packaging has excellent water vapor barrier properties. The lower the water vapor permeability of the substrate 10, the more preferable, and the lower limit of the water vapor permeability is 0 g / (m 2 ·day) is preferred. The water vapor permeability of the substrate 10 can be measured in accordance with the test method described in the moisture sensor method of JIS K7129:2008 under test condition 1 described in Table A.1. The water vapor permeability of the substrate 10 can be adjusted by the material and thickness of the substrate 10, the tensile modulus of elasticity in the MD direction, the tensile modulus of elasticity in the TD direction, or a combination thereof.

[0022] The water vapor permeability of the substrate 10 after the accelerated deterioration test was 4.0 g / (m 2 ·day) or less is preferable, and 2.0g / (m 2 ·day) or less is more preferable, and 1.0g / (m 2·day) or less is even more preferable. When the water vapor transmission rate of the substrate 10 after the accelerated deterioration test is the above upper limit or less, the packaging film 1 has excellent water vapor barrier properties with respect to repeated use. The lower the water vapor transmission rate of the substrate 10 after the accelerated deterioration test, the more preferable it is, and the lower limit of the water vapor transmission rate after the accelerated deterioration test is 0 g / (m 2 ·day) is preferred. The water vapor permeability of the substrate 10 after the accelerated deterioration test can be measured in the same manner as the water vapor permeability (initial) described above. The water vapor permeability of the substrate 10 after the accelerated deterioration test can be adjusted by the material and thickness of the substrate 10, the tensile modulus of elasticity in the MD direction, the tensile modulus of elasticity in the TD direction, or a combination of these.

[0023] When the substrate 10 is subjected to a heat flux differential scanning calorimeter (hereinafter also referred to as a DSC device) for calorimetry, endothermic peaks are observed at the melting points of the crystals (α crystals, β crystals, β' crystals, etc.) of the substrate 10. The melting points of the β crystals and β' crystals are lower than that of the α crystals. When the substrate 10 having β crystals is treated at high temperatures (e.g., 80°C or higher), the β crystals collapse, and a β' crystal group is formed, which is made up of β' crystals and crystals similar to β' crystals, which are less stable than β crystals. The β' crystal group has a more unstable crystal structure than the β crystals, and therefore multiple endothermic peaks are observed. In this manner, the formation of the β' crystal group can be determined by observing an endothermic peak in a DSC curve obtained by performing heat flux differential scanning calorimetry (DSC measurement).

[0024] For example, in the case of the DSC curve shown in FIG. 2, the curve C1 has a first endothermic peak P1 at 162.91° C. and a second endothermic peak P2 at 171.01° C. The endothermic peak P2 observed on the high temperature side is an endothermic peak derived from the melting point of the α crystal. The endothermic peak P1 observed on the low temperature side is a single peak and is considered to be an endothermic peak derived from the melting point of the β crystal. On the other hand, in the case of the DSC curve shown in FIG. 3, the curve C2 has an endothermic peak P3 branched at 163.37°C and 164.75°C, an endothermic peak P4 at 167.65°C, and an endothermic peak P5 at 170.99°C. The endothermic peak P5 observed on the high temperature side is an endothermic peak derived from the melting point of the α crystal. The multiple endothermic peaks P3 and P4 observed on the low temperature side are considered to be endothermic peaks derived from the melting point of the β' crystal group, not the β crystal. In this specification, when two or more endothermic peaks are observed in a DSC curve other than the endothermic peak due to the melting point of the α crystal, the two or more endothermic peaks are determined to be endothermic peaks due to the melting point of the β' crystal group.

[0025] The measurement conditions for the DSC measurement are as follows. An endothermic peak is observed from the DSC curve obtained during the first heating. The calorific value ratio of each endothermic peak is calculated using the analysis software of the DSC device based on the area of ​​each endothermic peak. The calorific value ratio of each endothermic peak is the average value of two DSC measurements performed on the same sample. (Measuring Equipment) Heat flux differential scanning calorimetry (DSC) device: Differential scanning calorimeter, DSC-60Plus (Shimadzu Corporation). (Measurement conditions) Sample size: 5.5±0.5mg. Reference (alumina) content: 5mg. Nitrogen gas flow rate: 20mL / min. Number of tests: 2. First heating condition: Heat from 20℃ to 190℃ at a heating rate of 5℃ / min. ·Holding time: 0min. First cooling condition: Cool down from 190℃ to 50℃ at a cooling rate of -5℃ / min. Second heating conditions: Heat from 50℃ to 190℃ at a heating rate of 5℃ / min. ·Holding time: 0min. Second cooling condition: Cool down from 190℃ to 50℃ at a cooling rate of -5℃ / min.

[0026] The calorific value ratio of the endothermic peak of the β' crystal group to the total calorific value of the endothermic peak of the substrate 10 measured by a DSC device is 10% or less, preferably 5% or less, more preferably 3% or less, and most preferably 0%. When the calorific value ratio of the endothermic peak of the β' crystal group is equal to or less than the upper limit, odor can be further reduced. When the calorific value ratio of the endothermic peak of the β' crystal group is 0%, it means that no endothermic peak derived from the melting point of the β' crystal group is observed. The calorific value ratio of the endothermic peak of the β' crystal group can be determined using analysis software for a DSC apparatus based on the area of ​​the endothermic peak of the β' crystal group observed in a DSC curve. The calorific value ratio of the endothermic peak of the β' crystal group can be adjusted by the treatment temperature, treatment time, or a combination thereof when the substrate 10 is heat-treated.

[0027] The calorific value ratio of the endothermic peak of α-crystal to the total calorific value of the endothermic peak of the substrate 10 measured by a DSC device is preferably 80% or more, more preferably 85% or more, and even more preferably 90% or more. When the calorific value ratio of the endothermic peak of α-crystal is equal to or more than the above lower limit, the strength of the substrate 10 can be further increased. In addition, when the calorific value ratio of the endothermic peak of α-crystal is equal to or more than the above lower limit, odor can be further reduced. The upper limit of the calorific value ratio of the endothermic peak of α-crystal is not particularly limited, but is, for example, 99%. The calorific value ratio of the endothermic peak of the α-crystal can be determined using analysis software for a DSC apparatus based on the area of ​​the endothermic peak of the α-crystal observed in a DSC curve. The calorific value ratio of the endothermic peak of the α crystal can be adjusted by the treatment temperature, treatment time, or a combination thereof when the substrate 10 is heat-treated.

[0028] Thickness T of the substrate 10 10 is determined taking into consideration the material, configuration, and the like, and is, for example, preferably 5 to 100 μm, and more preferably 10 to 50 μm. 10 When the thickness T of the substrate 10 is equal to or greater than the lower limit, the strength of the film for packaging 1 is increased. 10 When the thickness T of the substrate 10 is equal to or greater than the lower limit, the water vapor barrier property of the film 1 for packaging can be improved. 10When the thickness is equal to or less than the upper limit, the flexibility of the packaging film 1 is increased, making it easy to handle. Thickness T of the substrate 10 10 can be measured, for example, by a thickness gauge.

[0029] (base layer) The base layer 12 is made of a biaxially oriented polypropylene film. By using a biaxially oriented polypropylene film as the base layer 12, it is possible to improve the water vapor barrier property of the packaging film 1. This is believed to be because the crystallinity of polypropylene can be increased by stretching the polypropylene film. Examples of the polypropylene resin in the base layer 12 include homopolypropylene, a copolymer of polypropylene and polyethylene containing about 10% by mass of polyethylene, block polypropylene, etc. The base layer 12 may contain 50% by mass or more of polypropylene. The base layer 12 may be a single layer, or may be a multi-layer in which two or more layers are laminated.

[0030] Thickness T of base layer 12 12 is determined taking into consideration the material and the like, and is, for example, preferably 4.9 to 99 μm, and more preferably 10 to 50 μm. 12 When the thickness T of the base layer 12 is equal to or greater than the above lower limit, the strength of the packaging film 1 is increased. 12 When the thickness T of the base layer 12 is equal to or greater than the lower limit, the water vapor barrier property of the film for packaging material 1 can be improved. 12 When the thickness is equal to or less than the upper limit, the flexibility of the packaging film 1 is increased, making it easy to handle. Thickness T of base layer 12 12 can be measured, for example, by a thickness gauge.

[0031] (deposited layer) The vapor-deposited layer 14 has oxygen barrier properties, water vapor barrier properties, and light-shielding properties. That is, the vapor-deposited layer 14 in this embodiment has the role of suppressing the transmission of oxygen, water vapor, ultraviolet light, and visible light. In this embodiment, the vapor deposition layer 14 is formed on the base layer 12, not on the sealant material 20. Both the base layer 12 and the vapor deposition layer 14 are made of materials that are not easily stretched, so that the vapor deposition layer 14 is less likely to be damaged by friction or bending, and the vapor deposition layer 14 is less likely to peel off from the base layer 12. As a result, the oxygen barrier property and water vapor barrier property of the packaging film 1 against repeated use can be improved. In addition, in this embodiment, by having the vapor deposition layer 14, the light-blocking properties of the packaging film 1 can be further improved, and deterioration of the contents of the packaging body made from the packaging film 1 due to ultraviolet rays, etc. can be suppressed.

[0032] Examples of materials for forming the deposition layer 14 include aluminum (Al), silica (SiO2), etc. From the viewpoint of cost, excellent suitability for bending, and improved oxygen barrier properties and water vapor barrier properties against repeated use, aluminum is preferred as the material for forming the deposition layer 14.

[0033] Thickness T of the deposition layer 14 14 The thickness T of the deposition layer 14 is 20 to 100 nm, preferably 35 to 85 nm, and more preferably 50 to 70 nm. 14 When the thickness T of the vapor-deposited layer 14 is equal to or greater than the above lower limit, the oxygen barrier property and water vapor barrier property of the film 1 for packaging can be further improved. 14 When the thickness T of the vapor deposition layer 14 is equal to or less than the upper limit, the occurrence of delamination (interlayer peeling) due to cohesive failure can be suppressed. This can suppress the deterioration of the oxygen barrier property and the water vapor barrier property of the packaging film 1 with repeated use. 14 When the amount of the sintering agent is equal to or less than the upper limit, it is advantageous in terms of cost. Thickness T of the deposition layer 14 14 can be measured, for example, by observing a cross section obtained by cutting the packaging film 1 in the thickness direction with a microscope or the like.

[0034] <Adhesive layer> The adhesive layer 30 is located between the substrate 10 and the sealant material 20. The adhesive layer 30 is a cured product of an isocyanate-based adhesive containing a polyester polyol having a carbon-carbon double bond and a compound having an isocyanate group. The adhesive layer 30 has oxygen absorbing properties because the isocyanate-based adhesive contains a carbon-carbon double bond. In addition, the isocyanate-based adhesive of the present embodiment contains an oxygen absorber, so that the adhesive layer 30 absorbs oxygen and can suppress the oxygen from passing through the packaging film 1. Therefore, the packaging film 1 can have improved oxygen barrier properties by having the adhesive layer 30.

[0035] The isocyanate-based adhesive of the present embodiment is a urethane-based adhesive containing a base agent and a curing agent, and a polyester polyol having a carbon-carbon double bond is a base agent and a compound having an isocyanate group is a curing agent. The polyester polyol may be, for example, an unsaturated polyester made of a polyvalent carboxylic acid component containing at least one aromatic dicarboxylic acid or anhydride thereof. As the aromatic dicarboxylic acid or anhydride thereof, phthalic anhydride is preferred. Examples of the curing agent for the isocyanate-based adhesive of this embodiment include toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), hexamethylene diisocyanate (HDI), and isophorone diisocyanate (IPDI, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate). As the curing agent, IPDI is preferred from the viewpoints of low environmental impact and excellent adhesive strength.

[0036] The oxygen absorber may be at least one selected from the group consisting of conjugated diene polymer cyclized products, transition metal salts of organic acids, tetrahydrophthalic acid and derivatives of tetrahydrophthalic acid. Examples of the conjugated diene polymer cyclized product include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 2-phenyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 4,5-diethyl-1,3-octadiene, 3-butyl-1,3-octadiene, and polyterpenes obtained by cyclizing these compounds, such as poly(α-pinene), poly(β-pinene), and poly(dipentene). As the conjugated diene polymer cyclized product, polyisoprene cyclized product is preferable.

[0037] Examples of the transition metal salt of an organic acid include salts of a transition metal element and an organic acid. Examples of the transition metal element include iron, nickel, copper, manganese, cobalt, rhodium, titanium, chromium, vanadium, ruthenium, etc. As the transition metal element, iron, nickel, copper, manganese, and cobalt are preferable, manganese and cobalt are more preferable, and cobalt is further preferable. Examples of organic acids include acetic acid, stearic acid, dimethyldithiocarbamic acid, palmitic acid, 2-ethylhexanoic acid, neodecanoic acid, linoleic acid, tallic acid, oleic acid, resin acid, capric acid, naphthenic acid, etc. Preferred organic acids are stearic acid, palmitic acid, neodecanoic acid, linoleic acid, and oleic acid, and more preferred are neodecanoic acid and oleic acid. As the transition metal salt of an organic acid, cobalt neodecanoate and cobalt oleate are preferred.

[0038] Examples of tetrahydrophthalic acid or a derivative of tetrahydrophthalic acid include methyltetrahydrophthalic acid or a derivative thereof, and methyltetrahydrophthalic anhydride or a derivative thereof. Specific examples of such tetrahydrophthalic acid or a derivative thereof include 1,2,3,6-tetrahydrophthalic anhydride, 1,2,3,6-tetrahydrophthalimide, 3,4,5,6-tetrahydrophthalic anhydride, methyl-1,2,3,6-tetrahydrophthalic anhydride, and methyl-3,6-endomethylene-1,2,3,6-tetrahydrophthalic anhydride. As tetrahydrophthalic acid or a derivative of tetrahydrophthalic acid, methyltetrahydrophthalic acid or a derivative thereof, or methyltetrahydrophthalic anhydride or a derivative thereof is preferred, and methyl-1,2,3,6-tetrahydrophthalic anhydride is more preferred, because of their excellent oxygen absorbing properties. These oxygen absorbents may be used alone or in combination of two or more kinds.

[0039] The content of the oxygen absorbent is 1% by mass or more, preferably 1 to 10% by mass, more preferably 2 to 8% by mass, and even more preferably 3 to 6% by mass, based on the total mass of the isocyanate adhesive. When the content of the oxygen absorbent is equal to or more than the above lower limit, the oxygen barrier property of the packaging film 1 can be further improved. When the content of the oxygen absorbent is equal to or less than the above upper limit, the adhesion between the substrate 10 and the sealant 20 can be further improved. In addition, when the content of the oxygen absorbent is equal to or less than the above upper limit, it is advantageous in terms of cost.

[0040] The mass ratio of the base agent to the curing agent in the isocyanate adhesive is preferably 100:103 to 100:150, more preferably 100:103 to 100:130, and even more preferably 100:105 to 100:125. When the mass ratio of the base agent to the curing agent is equal to or greater than the above lower limit, the adhesiveness between the substrate 10 and the sealant 20 can be further improved. When the mass ratio of the base agent to the curing agent is equal to or less than the above upper limit, the water vapor barrier property of the packaging film 1 can be further improved.

[0041] The content of unreacted isocyanate groups in the adhesive layer 30 is preferably 3 to 30 mol %, more preferably 3 to 20 mol %, and even more preferably 5 to 10 mol %, based on the content of the generated urethane groups. When the content of unreacted isocyanate groups is equal to or greater than the above lower limit, the unreacted isocyanate groups absorb water vapor, and the water vapor barrier property of the packaging film 1 can be further improved. When the content of unreacted isocyanate groups is equal to or less than the above upper limit, the adhesion between the substrate 10 and the sealant material 20 can be further improved, which is also advantageous in terms of cost. The content of unreacted isocyanate groups can be measured by a Fourier transform infrared spectrophotometer (FTIR). Specifically, infrared light is irradiated onto the packaging film 1, and a transmission mapping measurement is performed using an infrared microscope. The spectrum obtained by the transmission mapping measurement is analyzed in the infrared wavelength range of 2,500 to 25,000 nm (2.5 to 25 μm) to determine the ratio of the peak height of the urethane group to the peak height of the isocyanate group in the adhesive layer 30, thereby making it possible to determine the content of unreacted isocyanate groups relative to the content of urethane groups.

[0042] The isocyanate adhesive may be a one-liquid adhesive or a two-liquid adhesive. As the isocyanate adhesive, a two-liquid adhesive consisting of a base agent and a curing agent is preferable from the viewpoint of a fast curing speed and excellent adhesive strength. The isocyanate-based adhesive may contain other components in addition to the base agent, the curing agent, and the oxygen absorber. Examples of the other components include additives and organic solvents that are generally used in adhesives. The content of the other components is preferably 0 to 20% by mass based on the total mass of the isocyanate-based adhesive.

[0043] Thickness T of adhesive layer 30 30 The thickness T of the adhesive layer 30 is preferably, for example, 1.5 to 5.0 μm, and more preferably 2.0 to 4.0 μm. 30 When the thickness T of the adhesive layer 30 is equal to or greater than the lower limit, the adhesiveness between the substrate 10 and the sealant material 20 can be further improved. 30 When the thickness T of the adhesive layer 30 is equal to or greater than the lower limit, the oxygen barrier property and water vapor barrier property of the film 1 for packaging can be further improved. 30 When it is equal to or less than the upper limit, cohesive failure of the adhesive layer 30 can be suppressed. Thickness T of adhesive layer 30 30 can be measured, for example, by observing a cross section obtained by cutting the packaging film 1 in the thickness direction with a microscope or the like.

[0044] <Sealant material> The sealant 20 is made of a non-oriented polypropylene film. Examples of the polypropylene in the non-oriented polypropylene film include homopolypropylene, a copolymer of polypropylene and polyethylene containing about 10% by mass of polyethylene, block polypropylene, etc. The sealant 20 may contain 50% by mass or more of polypropylene. Unstretched polypropylene film has excellent heat sealability. Therefore, by using an unstretched polypropylene film as the sealant material 20, the sealability when sealing the film for packaging 1 can be improved. As a result, the impact resistance of the package produced by making a bag from the film for packaging 1 can be improved. In addition, unstretched polypropylene film has excellent water vapor barrier properties. Therefore, by using an unstretched polypropylene film as the sealant material 20, the water vapor barrier property of the film for packaging 1 can be improved. The sealant material 20 may be a single layer, or may be a multi-layer in which two or more layers are laminated.

[0045] Sealant material 20 thickness T 20 The thickness T of the sealant material 20 is determined taking into consideration the material and the like, and is, for example, preferably 5 to 150 μm, more preferably 10 to 100 μm, and further preferably 20 to 60 μm. 20 When the thickness T of the sealant material 20 is equal to or greater than the above lower limit, the water vapor barrier property of the film 1 for packaging can be further improved. 20 When the thickness is equal to or less than the upper limit, the flexibility of the packaging film 1 is increased, making it easy to handle. Sealant material 20 thickness T 20 can be measured, for example, with a thickness gauge.

[0046] <Manufacturing method of packaging film> The manufacturing method of the packaging film 1 includes a step of obtaining a base layer 12 (base layer manufacturing step), a step of providing a vapor deposition layer 14 on one side of the base layer 12 to obtain a substrate 10 (substrate manufacturing step), a step of obtaining a sealant material 20 (sealant material manufacturing step), a step of laminating the substrate 10 and the sealant material 20 with an adhesive to obtain a laminate (laminate manufacturing step), and a step of subjecting the laminate to a heat treatment (heat treatment step).

[0047] <Base layer manufacturing process> The method for obtaining the base layer 12 in the base layer manufacturing step is selected from conventionally known methods such as an inflation method, a T-die method, and a co-extrusion method depending on the material and configuration of the base layer 12 .

[0048] <Base material manufacturing process> In the substrate manufacturing process, a vapor deposition layer 14 is provided on one side of the base layer 12. The method for providing the vapor deposition layer 14 on the base layer 12 is not particularly limited, and a conventionally known vacuum vapor deposition method can be applied (vapor deposition operation). In the deposition operation, the degree of vacuum in the deposition chamber is preferably 0.1 to 0.5 Pa, for example. In the deposition operation, the conveying speed of the base layer 12 is preferably, for example, 100 to 400 m / min. The deposition operation results in a substrate 10 having a base layer 12 and a deposition layer 14 formed on one side thereof.

[0049] <Sealant manufacturing process> The method for obtaining the sealant 20 in the sealant production process is selected from conventionally known methods such as an inflation method, a T-die method, a co-extrusion method, etc., depending on the material and configuration of the sealant 20 .

[0050] <Laminate manufacturing process> In the laminate manufacturing process, a laminate is manufactured of the substrate 10 and the sealant material 20. The method for laminating the substrate 10 and the sealant material 20 in the laminate manufacturing process is selected from conventionally known methods such as a dry lamination method. In the dry lamination method, for example, an adhesive is applied to the surface of the sealant material 20 to be laminated, the deposition layer 14 of the substrate 10 and the sealant material 20 are laminated via the adhesive, and each layer is pressed and dried to obtain a laminate. The obtained laminate is, for example, wound into a roll. The adhesive may be applied to the surface of the vapor-deposited layer 14 of the substrate 10 .

[0051] In the laminate manufacturing process, the obtained laminate is subjected to a heat treatment, which promotes the curing of the adhesive.

[0052] The temperature of the heat treatment is, for example, preferably 30 to 60°C, and more preferably 35 to 50°C. When the heat treatment temperature is equal to or higher than the lower limit, curing of the adhesive is sufficiently promoted, and the adhesion between the substrate 10 and the sealant material 20 can be further improved. When the heat treatment temperature is equal to or lower than the upper limit, damage to the layers constituting the laminate due to heat can be suppressed, and deterioration of the oxygen barrier property and water vapor barrier property of the packaging film 1 can be further suppressed.

[0053] The heat treatment time is, for example, preferably 5 hours or more, more preferably 5 to 96 hours, and even more preferably 12 to 48 hours. When the heat treatment time is equal to or more than the above lower limit, curing of the adhesive is sufficiently promoted, and the adhesion between the substrate 10 and the sealant material 20 can be further improved. When the heat treatment time is equal to or less than the above upper limit, the productivity of the packaging film 1 can be improved. The heat treatment of the laminate can be carried out in a conventionally known thermostatic chamber or the like. The laminate that has been subjected to this heat treatment can be distinguished from the laminate that has not been subjected to the heat treatment, for example, by analyzing the cured state of the adhesive of both of them by FTIR or nuclear magnetic resonance (NMR) spectroscopy.

[0054] <Heat treatment process> After the laminate is manufactured as described above, the laminate is further subjected to a heat treatment in the heat treatment step. By further heat treating the laminate, the crystallization of the base material 10 is promoted. In addition, by further heat treating the laminate, the calorific value ratio of the endothermic peak of the β' crystal group of the base material 10 can be controlled.

[0055] The temperature of the heat treatment is, for example, preferably 30 to 60°C, and more preferably 35 to 50°C. When the heat treatment temperature is equal to or higher than the lower limit, the crystallization of the substrate 10 is sufficiently promoted, and the strength of the packaging film 1 can be further increased. When the heat treatment temperature is equal to or lower than the upper limit, the generation of β' crystal groups can be suppressed, and the odor of the packaging film 1 can be further suppressed.

[0056] The heat treatment time is, for example, preferably 3 to 60 seconds, more preferably 3 to 30 seconds, and even more preferably 5 to 15 seconds. When the heat treatment time is equal to or more than the above lower limit, crystallization of the substrate 10 is sufficiently promoted, and the strength of the packaging film 1 can be further increased. When the heat treatment time is equal to or less than the above upper limit, the generation of β' crystal groups can be suppressed, and the odor of the packaging film 1 can be further suppressed. The heat treatment of the laminate can be carried out using a hot air blowing device or the like provided in the production line of the packaging film 1.

[0057] In addition to the steps described above, the method for producing the packaging film may also include a printing step of providing a printed layer (not shown) on the substrate 10 for the purpose of imparting a predetermined appearance to the packaging film. The printing process is not particularly limited, and various printing methods such as offset printing, gravure printing, flexographic printing, screen printing, and inkjet printing can be used.

[0058] ≪Packaging body≫ The packaging body of the present embodiment is a bag made from the packaging film 1 of the present embodiment. An example of the packaging body is a bag made by heat-sealing the sealant materials 20 of the packaging film 1 together. Examples of the form of the package include a palm-sealed bag, a three-side sealed bag, a four-side sealed bag, a gusseted bag, a stand-up bag, and bags with zippers attached to these bags. Further, for example, the packaging body may be a container comprising a container body having an opening and a lid body made of the packaging film 1, in which the sealant material 20 is applied to the periphery of the opening of the container body, and the packaging film 1 is heat-sealed to the container body. In this case, polypropylene is preferable as the material for the container body from the viewpoint of easy recycling.

[0059] As described above, the packaging film 1 of this embodiment can further suppress odor because the ratio of the heat quantity of the endothermic peak of the β' crystal group to the total heat quantity of the endothermic peak of the substrate 10 measured by a DSC device is 10% or less. The packaging film 1 of this embodiment includes the substrate 10 having the deposition layer 14 formed on the base layer 12, and therefore has excellent oxygen barrier properties and water vapor barrier properties even when used repeatedly. The packaging film 1 of this embodiment uses an isocyanate-based adhesive containing a polyester polyol having a carbon-carbon double bond and a compound having an isocyanate group, and therefore has excellent oxygen absorption properties and therefore excellent oxygen barrier properties. The film for packaging 1 of this embodiment has excellent oxygen absorbing properties because the adhesive layer 30 contains an oxygen absorbent, and therefore the film for packaging 1 of this embodiment has excellent oxygen barrier properties. In the packaging film 1 of this embodiment, both the base material 10 and the sealant material 20 are made of polypropylene resin. As described above, the packaging film 1 of this embodiment is a mono-material, and therefore can be easily recycled. A package produced using the film for packaging 1 of this embodiment has excellent heat sealing properties of the sealant 20, and therefore can maintain its seal strength and has excellent impact resistance. The packaging material produced using the packaging film 1 of this embodiment is a mono-material, and therefore can be easily recycled.

[0060] [Other embodiments] In the above embodiment, the substrate 10 is a single layer, but the present invention is not limited thereto, and the substrate 10 may be a multi-layer substrate made up of two or more layers. In the above embodiment, the substrate 10 is a single layer, but the present invention is not limited thereto, and a printed layer may be formed on one side of the substrate 10. By forming a printed layer on one side of the substrate 10, a predetermined appearance can be imparted to the packaging film, making the appearance beautiful. EXAMPLES

[0061] The present invention will be described below with reference to examples, but the present invention is not limited to the following examples. The materials and test conditions used in this example are as follows:

[0062] [Materials used] <Base material> (base layer) OPP1: Biaxially oriented polypropylene film, PYLENE (registered trademark) Film-OT (product name), manufactured by Toyobo Co., Ltd., thickness 30 μm. OPP2: Biaxially oriented polypropylene film, PYLENE® Film-OT (product name), manufactured by Toyobo Co., Ltd., thickness 20 μm. (deposited layer) <Deposition conditions> - Name of deposition equipment: Roll-type vacuum deposition equipment EWA series (product name), manufactured by ULVAC, Inc. · Evaporation source: Aluminum (Al) or Silicon (Si). - Vacuum level in deposition chamber: 0.2 Pa. -Film conveying speed: 200m / min.

[0063] <Sealant material> CPP1: Non-oriented polypropylene film, Pylen® Film-CT (product name), manufactured by Toyobo Co., Ltd., thickness 30 μm. · CPP2: Non-oriented polypropylene film, Taiko (registered trademark) FC (product name), manufactured by Futamura Chemical Co., Ltd., thickness 30 μm (coextrusion layer of three layers of 10 μm-thick CPP). · CPP3: CPP1 is an aluminum-deposited non-oriented polypropylene film with a 60 nm thick aluminum-deposited layer on one side.

[0064] <Adhesive layer> (Main ingredient) Saturated polyester: Manufactured by Nippon Synthetic Chemical Industry Co., Ltd. ·Phthalic anhydride: Manufactured by Junsei Chemical Co., Ltd. (hardening agent) IPDI: Isophorone diisocyanate, Takenate®, manufactured by Mitsui Chemicals, Inc. · TDI: Toluene diisocyanate, Takenate (registered trademark), manufactured by Mitsui Chemicals, Inc. (Oxygen absorber) Conjugated diene: Conjugated diene polymer cyclized product (polyisoprene cyclized product). · Transition metals: Transition metal salts of organic acids, cobalt neodecanoate, manufactured by Nippon Chemical Industries Co., Ltd. Tetrahydrophthalic acid: 3or4-Methyl-1,2,3,6-tetrahydrophthalic anhydride, manufactured by Showa Denko Materials Co., Ltd.

[0065] [Examples 1 to 7, Comparative Examples 1 to 6] An adhesive containing an oxygen absorbent shown in Table 1 was applied to a sealant shown in Table 1, and the surface of the deposition layer of the base material on which a deposition layer with a thickness shown in Table 1 had been formed was laminated with the adhesive-coated surface of the sealant to obtain a laminate. This laminate was subjected to a heat treatment under the heat treatment conditions shown in Table 1 (heat treatment step) to produce films for packaging according to the configurations of Examples 1 to 7 and Comparative Examples 1 to 6. However, in Comparative Example 1, a film for packaging was produced in the same manner as in Example 1, except that an adhesive was applied to the surface of the aluminum deposition layer of the sealant. In the table, "-" in Comparative Example 1 indicates that no deposition layer was formed on the base material. "-" in Comparative Example 2 indicates that no oxygen absorbent was included.

[0066] [Evaluation method] <Measurement of crystal growth rate> DSC measurements were performed on the substrates used in each example. The measurement conditions for the DSC measurements are as follows. Endothermic peaks were observed from the DSC curve obtained during the first heating. The heat ratio of each endothermic peak was calculated using the analysis software of the DSC device based on the area of ​​each endothermic peak. The heat ratio of each endothermic peak was taken as the average value of two DSC measurements performed on the same sample. The heat ratio of each endothermic peak was taken as the crystallization rate (%) of each crystal. The results are shown in Table 1. (Measuring Equipment) Heat flux differential scanning calorimetry (DSC) device: Differential scanning calorimeter, DSC-60Plus (Shimadzu Corporation). (Measurement conditions) Sample size: 5.5±0.5mg. Reference (alumina) content: 5mg. Nitrogen gas flow rate: 20mL / min. Number of tests: 2. First heating condition: Heat from 20℃ to 190℃ at a heating rate of 5℃ / min. ·Holding time: 0min. First cooling condition: Cool down from 190℃ to 50℃ at a cooling rate of -5℃ / min. Second heating conditions: Heat from 50℃ to 190℃ at a heating rate of 5℃ / min. ·Holding time: 0min. Second cooling condition: Cool down from 190℃ to 50℃ at a cooling rate of -5℃ / min.

[0067] <Measurement of residual solvent amount (evaluation of odor)> For the packaging films obtained in each example, the amount of residual solvent was measured using a capillary gas chromatograph, and the odor was evaluated based on the following evaluation criteria. The results are shown in Table 2. Evaluation Criteria ◎: Residual solvent amount 2.0mg / m 2 below. ○: Residual solvent amount 2.0 mg / m 2 Super 5.0mg / m 2 below. ×: Residual solvent amount 5.0 mg / m 2 Super.

[0068] <Evaluation of oxygen barrier properties (initial stage)> For the packaging films obtained in each example, the oxygen permeability was measured according to the oxygen gas permeability test method using an electrolytic sensor as described in Appendix A of JIS K7126-2:2006, and the oxygen barrier property was evaluated based on the following evaluation criteria. The results are shown in Table 2. Evaluation Criteria ◎: Oxygen permeability 2.0mL / (m 2 ·day) or less. ○: Oxygen permeability 2.0mL / (m 2 ·day)Ultra 4.0mL / (m 2 ·day) or less. ×: Oxygen permeability 4.0mL / (m 2 ·day) Super 12mL / (m 2 ·day) or less. ××: Oxygen permeability 12mL / (m 2 ·day) Super.

[0069] <Evaluation of oxygen barrier properties (after Gelbo test)> The packaging film obtained in each example was subjected to a Gelbo test, and the oxygen permeability after the Gelbo test was measured. The Gelbo test was carried out using a Gelbo flex tester (MIL-B131H, manufactured by Rigaku Kogyosha). Using the above Gelbo flex tester, a packaging film cut to a size of 21 cm x 29 cm was twisted 400° with a stroke of 3 inches (7.62 cm) under conditions of 23°C and relative humidity of 65%. This reciprocating motion was repeated 100 times at a speed of 40 times per minute (40 times / min), and then the oxygen permeability was measured in the same manner as in the above <Evaluation of oxygen barrier property (initial)>. The oxygen barrier property was evaluated based on the measured oxygen permeability value and the following evaluation criteria. The results are shown in Table 2. Evaluation Criteria ◎: Oxygen permeability 2.0mL / (m 2 ·day) or less. ○: Oxygen permeability 2.0mL / (m 2 ·day)Ultra 6.0mL / (m 2 ·day) or less. ×: Oxygen permeability 6.0mL / (m2 ·day) Super 12mL / (m 2 ·day) or less. ××: Oxygen permeability 12mL / (m 2 ·day) Super.

[0070] <Evaluation of water vapor barrier properties (after Gelbo test)> The packaging films obtained in each example were subjected to the Gelbo test in the same manner as described above in <Evaluation of oxygen barrier property (after Gelbo test)>. For the packaging films after the Gelbo test, the water vapor permeability was measured under test condition 1 in Table A.1 in accordance with the test method described in the moisture sensor method of JIS K7129:2008, and the water vapor barrier property was evaluated based on the following evaluation criteria. The results are shown in Table 2. Evaluation Criteria ◎: Water vapor permeability 2.0g / (m 2 ·day) or less. ○: Water vapor permeability 2.0g / (m 2 ·day) Super 4.0g / (m 2 ·day) or less. ×: Water vapor permeability 4.0g / (m 2 ·day) Super.

[0071] <Overall rating> Based on the odor evaluation, oxygen barrier property evaluation (initial), oxygen barrier property evaluation (after Gelbo test), and water vapor barrier property evaluation (after Gelbo test), each example of the packaging film was comprehensively evaluated according to the following evaluation criteria. The results are shown in Table 2. Films with a comprehensive evaluation of "◎" or "○" were deemed to have passed. Evaluation Criteria ◎: All evaluation results are “◎”. ○: The evaluation result contains one or more “○” and no “×” in the evaluation result. ×: There is no "×" in the odor evaluation results, and there are one or two "×" in the odor evaluation results. XX: The odor evaluation result is "X", or there are three or more "X"s in the evaluation results.

[0072] [Table 1]

[0073] [Table 2]

[0074] As shown in Table 2, the packaging films of Examples 1 to 7 to which the present invention was applied received an overall rating of "◎" or "○", demonstrating that they had excellent oxygen barrier properties and water vapor barrier properties with repeated use and had reduced odor. In contrast, Comparative Example 1, in which the base material was not provided with a deposition layer but the sealant material was provided with a deposition layer, was evaluated as "x" for oxygen barrier property and water vapor barrier property after the Gelbo test. Comparative Example 2, in which the adhesive layer did not contain an oxygen absorber, was evaluated as "x" for oxygen barrier property. Comparative Example 3, in which the heat ratio of the endothermic peak of the β' crystal group was outside the range of the present invention, was evaluated as "x" for odor. Comparative Example 4, in which the thickness of the deposition layer was outside the range of the present invention, was evaluated as "x" for odor and oxygen barrier property. Comparative Example 5, in which the thickness of the deposition layer was outside the range of the present invention, was evaluated as "xx" for oxygen barrier property and as "x" for water vapor barrier property after the Gelbo test. Comparative Example 6, in which the thickness of the deposition layer was outside the range of the present invention, was evaluated as "x" for initial oxygen barrier property, "xx" for oxygen barrier property after the Gelbo test, and "x" for water vapor barrier property after the Gelbo test.

[0075] From the above results, it was confirmed that application of the present invention provides excellent oxygen barrier properties and water vapor barrier properties with repeated use, and reduces odors. [Explanation of symbols]

[0076] 1 Packaging film 10 Base material 12 Base layer 14 Deposited layer 20 Sealant 30 Adhesive layer

Claims

1. A substrate having a deposition layer formed on one side of a base layer made of a biaxially oriented polypropylene film; A sealant material located on one surface of the base material and made of a non-oriented polypropylene film; an adhesive layer located between the substrate and the sealant material; the deposition layer faces the sealant material, The thickness of the deposition layer is 20 to 100 nm; the adhesive layer is a cured product of an isocyanate-based adhesive containing a polyester polyol having a carbon-carbon double bond and a compound having an isocyanate group, The isocyanate-based adhesive contains an oxygen absorber, The content of the oxygen absorber is 1% by mass or more based on the total mass of the isocyanate-based adhesive, a ratio of the heat quantity of the endothermic peak of the β' crystal group derived from the β crystal to the total heat quantity of the endothermic peak of the base material measured by a heat flux differential scanning calorimeter is 10% or less; and the ratio of the heat quantity of the endothermic peak of the β crystal to the total heat quantity of the endothermic peak of the base material measured by a heat flux differential scanning calorimeter is 1 to 20%. Packaging film.

2. α relative to the total heat quantity of the endothermic peak of the substrate measured by a heat flux differential scanning calorimeter 2. The film for packaging according to claim 1, wherein the calorific value ratio of the endothermic peak of the crystal is 80% or more.

3. The oxygen absorber is a conjugated diene polymer cyclized product, a transition metal salt of an organic acid, a tetrahydrofuran 3. The compound according to claim 1 or 2, which is at least one selected from the group consisting of derivatives of phthalic acid and tetrahydrophthalic acid. The packaging film described above.

4. A packaging body produced by using the packaging film according to any one of claims 1 to 3.

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