Film for packaging body and packaging body

Abstract

To provide a film for a package and a package which have oxygen barrier property, water vapor barrier property, light shielding property and impact resistance and can be easily recycled.SOLUTION: There is provided a film for a package 1 which comprises a base material 10 in which a coating layer 14 containing a specific amount of titanium dioxide is formed on the 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 in which an aluminum vapor deposition layer 24 having a specific thickness is formed on one surface of a sealant layer 22 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.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a film for a package and a package.

Background Art

[0002] Gas barrier films having a function of shielding oxygen and water vapor are known and are also widely used as packaging materials. It is known that contents such as foods and drugs cause quality deterioration by ultraviolet rays and oxygen. For example, fats and oils are strongly affected by ultraviolet rays and oxidative deterioration progresses. Many natural pigments are unstable to ultraviolet rays and may change color.

[0003]

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the invention of Patent Document 1, since various functions are imparted by combining a plurality of materials having different characteristics, there is a problem that recycling is difficult.

[0006] The present invention has been made in view of the above circumstances, and an object thereof is to provide a film for a package and a package that have oxygen barrier properties, water vapor barrier properties, light shielding properties, and impact resistance and can be easily recycled.

Means for Solving the Problems

[0007] As a result of intensive studies, the present inventors have found that a film for a package having the following configuration can solve the above problems. That is, the film for a package of the present invention has the following configuration. [1] On the surface of a base layer made of a biaxially stretched polypropylene film, a coating layer containing 0.5 to 5.0 g / m 2 of titanium dioxide is formed, a sealant material located on one surface of the base material and having an aluminum vapor deposition layer formed on one side of a sealant layer made of an unstretched polypropylene film, and an adhesive layer located between the base material and the sealant material, wherein the aluminum vapor deposition layer faces the base material, the thickness of the aluminum vapor 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, and the content of the oxygen absorber is 1% by mass or more based on the total mass of the isocyanate-based adhesive. A film for a package. [2]A base material which is a biaxially stretched polypropylene film, a sealant material located on one surface of the base material, on one side of a sealant layer made of an unstretched polypropylene film, an aluminum vapor deposition layer is formed, an adhesive layer located between the base material and the sealant material, the base material contains titanium dioxide, the content of the titanium dioxide is more than 5% by mass and less than 50% by mass with respect to the total mass of the base material, the aluminum vapor deposition layer faces the base material, the thickness of the aluminum vapor 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, and the content of the oxygen absorber is 1% by mass or more with respect to the total mass of the isocyanate-based adhesive, a film for a package. [3]The film for a package according to [1] or [2], wherein the oxygen absorber is at least one selected from a conjugated diene polymer cyclized product and a transition metal salt. [4]A package in which the film for a package according to any one of [1] to [3] is made into a bag.

Advantages of the Invention

[0008] According to the film for a package of the present invention, it has oxygen barrier properties, water vapor barrier properties, light shielding properties and impact resistance, and can be easily recycled.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0010] The film for a package of the present invention includes a base material in which a coating layer containing titanium dioxide is formed on a base layer made of a biaxially stretched polypropylene film, and a sealant material located on one surface of the base material, in which an aluminum vapor deposition layer is formed on a sealant layer made of an unstretched polypropylene film. In the film for a package of the present invention, the resin of the base material and the resin of the sealant material are of the same type (polypropylene). Therefore, when recovering the film for a package of the present invention, it is not necessary to separately recover the base material and the sealant material, and it can be easily recycled.

[0011] [First Embodiment] ≪Film for Package≫ The film for a package according to the first embodiment of the present invention will be described with reference to the drawings. The film for a package 1 in FIG. 1 is formed by laminating a base material 10, an adhesive layer 30, and a sealant material 20 in this order. That is, the film for a package 1 includes a base material 10 in which a coating layer 14 is formed on the surface of a base layer 12, a sealant material 20 located on one surface of the base material 10, and an adhesive layer 30 located between the base material 10 and the sealant material 20. The sealant material 20 is formed with an aluminum vapor deposition layer 24 on one side of a sealant layer 22. The surface of the coating layer 14 of the base material 10 faces the surface of the aluminum vapor deposition layer 24 of the sealant material 20.

[0012] The oxygen permeability of the film for a package 1 is preferably 4.0 mL / (m 2 ·day) or less, more preferably 2.0 mL / (m 2 ·day) or less, and even more preferably 1.0 mL / (m 2 ·day) or less. When the oxygen permeability of the film for a package 1 is below the above upper limit value, it has excellent oxygen barrier properties. The lower the oxygen permeability of the film for a package 1, the more preferable it is, and the lower limit value of the oxygen permeability is preferably 0 mL / (m 2 ·day). The oxygen permeability of the film for a package 1 can be measured according to the test method for oxygen gas permeability by the electrolytic sensor method described in Appendix A of JIS K7126-2:2006. The oxygen permeability of the film 1 for the package can be adjusted by the material and thickness of the base material 10, the material and thickness of the sealant material 20, the thickness of the aluminum vapor deposition layer 24, the type and content of the oxygen absorber, and combinations thereof.

[0013] The light transmittance of the film 1 for the package at a wavelength of 450 nm of visible light (hereinafter, also simply referred to as "light transmittance") is preferably 20% or less, more preferably 10% or less, and even more preferably 4% or less. When the light transmittance of the film 1 for the package is equal to or less than the above upper limit value, the light shielding property is excellent. The lower the light transmittance of the film 1 for the package, the more preferable it is, and the lower limit value of the light transmittance is preferably 0%. The light transmittance of the film 1 for the package can be measured, for example, using an ultraviolet-visible spectrophotometer. The light transmittance of the film 1 for the package can be adjusted by the material and thickness of the coating layer 14, the content of the light shielding inorganic substance, the thickness of the aluminum vapor deposition layer 24 described later, and combinations thereof.

[0014] The thickness T1 of the film 1 for the package is not particularly limited, but for example, 35 to 250 μm is preferable, 40 to 200 μm is more preferable, and 50 to 150 μm is even more preferable. When the thickness T1 is equal to or greater than the above lower limit value, the strength of the film 1 for the package is increased. When the thickness T1 is equal to or less than the above upper limit value, the flexibility of the film 1 for the package is increased and handling becomes easy. The thickness T1 of the film 1 for the package can be measured, for example, using a thickness gauge or the like.

[0015] <Base material> The base material 10 is formed by forming a coating layer 14 on one side of a base layer 12 made of a biaxially stretched polypropylene film. The coating layer 14 is located between the base layer 12 and the sealant material 20. That is, the coating layer 14 is formed on the surface of the base layer 12 on the side of the sealant material 20.

[0016] The thickness T of the base material 10 10 is determined in consideration of the material, configuration, etc., and for example, 5 to 100 μm is preferable, and 10 to 50 μm is more preferable. The thickness T of the base material 10 10If it is equal to or greater than the above lower limit value, the strength of the film 1 for the package is enhanced. In addition, the thickness T of the base material 10 10 If it is equal to or greater than the above lower limit value, the water vapor barrier property of the film 1 for the package is enhanced. The thickness T of the base material 10 10 If it is equal to or less than the above upper limit value, the flexibility of the film 1 for the package is enhanced, and handling becomes easier. The thickness T of the base material 10 10 can be measured, for example, with a thickness gauge or the like.

[0017] (Base layer) The base layer 12 is made of a biaxially stretched polypropylene film. By using a biaxially stretched polypropylene film as the base layer 12, the water vapor barrier property of the film 1 for the package can be enhanced. This is presumably because the crystallinity of polypropylene can be increased by stretching the polypropylene film. Examples of the polypropylene in the base layer 12 include homopolypropylene, a copolymer of polypropylene containing about 10% by mass of polyethylene and polyethylene, and block polypropylene. The base layer 12 only needs to contain 50% by mass or more of polypropylene. The base layer 12 may be a single layer or a multilayer in which two or more layers are laminated.

[0018] The base layer 12 preferably has an orientation degree α in the MD direction (the flow direction during film production) of 0.5 to 2.5, more preferably 0.7 to 2.0, and even more preferably 1.0 to 1.5. When the orientation degree α is equal to or greater than the above lower limit value, the film 1 for the package is more excellent in water vapor barrier property. When the orientation degree α is equal to or less than the above upper limit value, the impact resistance of the package formed by bagging the film 1 for the package can be further enhanced. The base layer 12 preferably has an orientation degree β in the TD direction (the direction perpendicular to the MD direction) of 0.2 to 2.5, more preferably 0.5 to 2.0, and even more preferably 0.7 to 1.5. When the orientation degree β is equal to or greater than the above lower limit value, the film 1 for the package is more excellent in water vapor barrier property. When the orientation degree β is equal to or less than the above upper limit value, the impact resistance of the package formed by bagging the film 1 for the package can be further enhanced. The ratio represented by the degree of orientation α / the degree of orientation β is preferably from 0.5 to 2.0, more preferably from 0.5 to 1.5.

[0019] The degree of orientation α and the degree of orientation β are calculated from the values measured by the infrared dichroism method. The degree of orientation is measured by a transmission method using light called linearly polarized light, in which the electric field of light vibrates only in a certain direction, with an infrared spectrophotometer. As a measurement method, first, after performing BKG (background) measurement with the installation angle of the polarizer set to 0° (the direction of the electric field is the vertical direction), the stretching direction of the sample is aligned vertically, and the absorbance is measured (at this time, the polarization direction and the stretching axis direction are parallel). The obtained value is defined as the absorbance “A / / ”. Next, the sample is rotated by 90°, and the absorbance is measured with the stretching axis of the sample and the polarization direction perpendicular to each other. The obtained value is defined as the absorbance “A⊥”. The degree of orientation is defined as the absorbance ratio of the two absorbances A / / and A⊥ obtained with polarized light parallel to the stretching axis of the sample and polarized light perpendicular to it. The measurement wave number in the infrared dichroism method is appropriately selected according to the material to be measured (see "Seiji Kobayashi, 'Molecular Orientation by Infrared Dichroism Method', Journal of the Society of Polymer Science 'Polymer', Vol. 15, No. 175, p. 877-883"). In addition, the degree of orientation can be simply determined from the tensile modulus of elasticity measured according to JIS K7127:1999.

[0020] The water vapor transmission rate of the base layer 12 is preferably 4.0 g / (m 2 ·day) or less, more preferably 2.0 g / (m 2 ·day) or less, and even more preferably 1.0 g / (m 2 ·day) or less. When the water vapor transmission rate of the base layer 12 is below the above upper limit value, the film 1 for packaging has excellent water vapor barrier properties. The smaller the water vapor transmission rate of the base layer 12, the more preferable it is, and the lower limit value of the water vapor transmission rate is preferably 0 g / (m 2 ·day). The water vapor transmission rate of the base layer 12 can be measured under test condition 1 described in Table A.1 in accordance with the test method described in the humidity sensor method of JIS K7129:2008. The water vapor transmission rate of the base layer 12 can be adjusted according to the material, thickness, and combinations thereof of the base layer 12.

[0021] The thickness T of the base layer 12 12 is determined in consideration of materials, configurations, etc. For example, 4.5 to 95 μm is preferable, and 9.5 to 45 μm is more preferable. The thickness T of the base layer 12 12 If it is at least the above lower limit value, the strength of the film 1 for packaging can be increased. In addition, if the thickness T of the base layer 12 12 is at least the above lower limit value, the water vapor barrier property of the film 1 for packaging can be enhanced. If the thickness T of the base layer 12 12 is at most the above upper limit value, the flexibility of the film 1 for packaging is enhanced, and handling becomes easy. The thickness T of the base layer 12 12 can be measured, for example, with a thickness gauge or the like.

[0022] (Coating layer) The coating layer 14 is provided on one surface of the base layer 12. The coating layer 14 contains titanium dioxide as a light-shielding inorganic substance. The film 1 for packaging has excellent light-shielding properties by having the coating layer 14. The content of titanium dioxide is 0.5 to 5.0 g / m per unit area of the coating layer 14 2 and 1.0 to 4.0 g / m 2 is preferable, and 1.5 to 3.0 g / m 2 is more preferable. If the content of titanium dioxide is at least the above lower limit value, the light-shielding property of the film 1 for packaging can be further enhanced. If the content of titanium dioxide is at most the above upper limit value, aggregation failure of the coating layer 14 is suppressed, and delamination is easily suppressed. If the film 1 for packaging causes delamination, the light transmittance increases and the light-shielding property decreases. In addition, if the film 1 for packaging causes delamination, the impact resistance of the package formed by bagging the film 1 for packaging decreases. Therefore, if the content of titanium dioxide is at most the above upper limit value, a decrease in light-shielding property and a decrease in impact resistance can be suppressed. The content of titanium dioxide in the coating layer 14 can be calculated from the content of titanium dioxide contained in the coating agent forming the coating layer 14 and the coating amount of the coating agent.

[0023] The light-shielding inorganic substance contained in the coating layer 14 is titanium dioxide (titanium(IV) oxide). When, for example, calcium carbonate is used as the light-shielding inorganic substance, it is difficult to form a uniform coating film on one surface of the base layer 12. For this reason, a coating layer using calcium carbonate as the light-shielding inorganic substance is likely to cause a delamination phenomenon and the light-shielding property decreases. Further, when, for example, zinc oxide is used as the light-shielding inorganic substance, it is difficult to obtain sufficient scattering intensity and the light-shielding property cannot be enhanced.

[0024] The average primary particle diameter of the titanium dioxide contained in the coating layer 14 is preferably 100 to 500 nm, more preferably 200 to 400 nm. When the average primary particle diameter of the titanium dioxide is at least the above lower limit value, it is easy to scatter visible light and easy to enhance the light-shielding property. When the average primary particle diameter of the titanium dioxide is at most the above upper limit value, it is easy to form the coating layer 14 into a uniform coating film. The average primary particle diameter of the titanium dioxide is determined, for example, by analyzing an image taken using a transmission electron microscope.

[0025] The thickness T of the coating layer 14 14 is, for example, preferably 0.5 to 5.0 μm, more preferably 1.0 to 4.0 μm, and still more preferably 1.5 to 3.0 μm. The thickness T of the coating layer 14 14 When it is at least the above lower limit value, the light-shielding property of the film 1 for a package can be further enhanced. The thickness T of the coating layer 14 14 When it is at most the above upper limit value, aggregation breakdown of the coating layer 14 can be further suppressed. The thickness T of the coating layer 14 14 is measured, for example, by observing a cut surface obtained by cutting the film 1 for a package in the thickness direction with a microscope or the like.

[0026] <Adhesive layer> The adhesive layer 30 is provided on the surface of the coating layer 14 of the base material 10. That is, the adhesive layer 30 is located between the base material 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. Since the adhesive layer 30 has a carbon-carbon double bond in the components of the isocyanate-based adhesive, it has oxygen absorption properties. In addition, since the isocyanate-based adhesive of the present embodiment contains an oxygen absorber, the adhesive layer 30 can absorb oxygen and suppress the permeation of oxygen through the packaging film 1. Therefore, the packaging film 1 can have higher oxygen barrier properties by having the adhesive layer 30.

[0027] In the isocyanate-based adhesive of the present embodiment, the polyester polyol having a carbon-carbon double bond is the main agent, and the compound having an isocyanate group is the curing agent. That is, the isocyanate-based adhesive of the present embodiment is a urethane-based adhesive containing a main agent and a curing agent. Examples of the polyester polyol include unsaturated polyesters composed of a polyvalent carboxylic acid component containing at least one aromatic dicarboxylic acid or its anhydride. Phthalic anhydride is preferred as the aromatic dicarboxylic acid or its anhydride. Examples of the curing agent for the isocyanate-based adhesive of the present embodiment include toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate), and the like. From the viewpoint of low environmental impact and excellent adhesive strength, IPDI is preferred as the curing agent.

[0028] Examples of the oxygen absorber include one or more selected from conjugated diene polymer cyclized products and transition metal salts. Examples of the conjugated diene polymer cyclized product include polyterpenes such as 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, or poly(α-pinene), poly(β-pinene), poly(dipentene), etc. obtained by cyclizing these compounds. As the conjugated diene polymer cyclized product, a polyisoprene cyclized product is preferable.

[0029] Examples of the transition metal salt include salts of transition metal elements and organic acids. 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, cobalt are preferable, manganese and cobalt are more preferable, and cobalt is even more preferable. Examples of the organic acid include acetic acid, stearic acid, dimethyldithiocarbamic acid, palmitic acid, 2-ethylhexanoic acid, neodecanoic acid, linoleic acid, toluic acid, oleic acid, resin acid, capric acid, naphthenic acid, etc. As the organic acid, stearic acid, palmitic acid, neodecanoic acid, linoleic acid, oleic acid are preferable, and neodecanoic acid and oleic acid are preferable. As the transition metal salt, cobalt neodecanoate and cobalt oleate are preferable. These oxygen absorbers may be used alone or in combination of two or more.

[0030] The content of the oxygen absorber is 1% by mass or more based on the total mass of the isocyanate-based adhesive, preferably 1 to 10% by mass, more preferably 3 to 8% by mass, and even more preferably 4 to 6% by mass. When the content of the oxygen absorber is at least the above lower limit value, the oxygen barrier property of the film 1 for packaging can be further enhanced. When the content of the oxygen absorber is at most the above upper limit value, the adhesiveness between the base material 10 and the sealant material 20 can be further enhanced. In addition, when the content of the oxygen absorber is at most the above upper limit value, it is advantageous in terms of cost.

[0031] In the isocyanate-based adhesive, the mass ratio of the main agent to the curing agent is preferably from 100:103 to 100:150, more preferably from 100:103 to 100:130, and even more preferably from 100:105 to 100:125. When the mass ratio of the main agent to the curing agent is at least the above lower limit value, the adhesiveness between the base material 10 and the sealant material 20 can be further enhanced. When the mass ratio of the main agent to the curing agent is at most the above upper limit value, the water vapor barrier property of the film 1 for packaging can be further enhanced.

[0032] The content of the 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% with respect to the content of the generated urethane groups. When the content of the unreacted isocyanate groups is at least the above lower limit value, since the unreacted isocyanate groups absorb water vapor, the water vapor barrier property of the film 1 for packaging can be further enhanced. When the content of the unreacted isocyanate groups is at most the above upper limit value, the adhesiveness between the base material 10 and the sealant material 20 can be further enhanced, which is also advantageous in terms of cost. The content of the unreacted isocyanate groups can be measured by a Fourier transform infrared spectrophotometer (FTIR). Specifically, the film 1 for packaging is irradiated with infrared light, and transmission mapping measurement is performed using an infrared microscope. The spectrum obtained by the transmission mapping measurement is analyzed in the range of the wavelength of the infrared light of 2,500 to 25,000 nm (2.5 to 25 μm), and by obtaining the ratio of the height of the peak of the urethane groups to the height of the peak of the isocyanate groups in the adhesive layer 30, the content of the unreacted isocyanate groups with respect to the content of the urethane groups can be obtained.

[0033] The isocyanate-based adhesive may be a one-component type adhesive or a two-component type adhesive. From the viewpoint of fast curing speed and excellent adhesive strength, a two-component type adhesive of the main agent and the curing agent is preferred as the isocyanate-based adhesive. The isocyanate-based adhesive may contain a main agent, a curing agent, and other components other than the oxygen absorber. Examples of the other components include additives and organic solvents commonly 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.

[0034] The thickness T of the adhesive layer 30 30 is preferably, for example, 1.5 to 5.0 μm, more preferably 2.0 to 4.0 μm. When the thickness T of the adhesive layer 30 30 is equal to or greater than the above lower limit value, the adhesiveness between the base material 10 and the sealant material 20 can be further enhanced. In addition, when the thickness T of the adhesive layer 30 30 is equal to or greater than the above lower limit value, the oxygen barrier property and water vapor barrier property of the packaging film 1 can be further enhanced. When the thickness T of the adhesive layer 30 30 is equal to or less than the above upper limit value, cohesive failure of the adhesive layer 30 can be suppressed. The thickness T of the adhesive layer 30 30 can be measured, for example, by observing a cut surface obtained by cutting the packaging film 1 in the thickness direction with a microscope or the like.

[0035] <Sealant material> The sealant material 20 is formed by forming an aluminum vapor deposition layer 24 on one side of a sealant layer 22 made of an unstretched polypropylene film. That is, the sealant material 20 is an aluminum vapor-deposited unstretched polypropylene film. The surface of the aluminum vapor deposition layer 24 of the sealant material 20 faces one surface of the base material 10. By using an aluminum vapor-deposited unstretched polypropylene film as the sealant material 20, the packaging film 1 is excellent in oxygen barrier property, water vapor barrier property, light shielding property, and impact resistance.

[0036] The thickness T of the sealant material 20 20 is determined in consideration of the material, configuration, etc., and is preferably, for example, 5 to 150 μm, more preferably 10 to 100 μm, and even more preferably 20 to 60 μm. When the thickness T of the sealant material 20 20 is equal to or greater than the above lower limit value, the oxygen barrier property, water vapor barrier property, and light shielding property of the packaging film 1 can be further enhanced. When the thickness T of the sealant material 2020 When it is below the above upper limit value, the flexibility of the film 1 for packaging is enhanced and handling becomes easier. The thickness T of the sealant material 20 20 can be measured, for example, with a thickness gauge.

[0037] (Sealant layer) The sealant layer 22 is made of an unstretched polypropylene film. Examples of the polypropylene in the unstretched polypropylene film include homopolypropylene, a copolymer of polypropylene containing about 10% by mass of polyethylene and polyethylene, block polypropylene, and the like. The sealant layer 22 may contain 50% by mass or more of polypropylene. The unstretched polypropylene film is excellent in heat sealability. Therefore, by using the unstretched polypropylene film as the sealant layer 22, the sealability when sealing the film 1 for packaging can be enhanced. As a result, the impact resistance of the package formed by bagging the film 1 for packaging can be enhanced. The sealant layer 22 may be a single layer or a multilayer in which two or more layers are laminated.

[0038] The thickness T of the sealant layer 22 22 is determined in consideration of materials and the like. For example, 5 to 100 μm is preferable, 5 to 90 μm is more preferable, and 10 to 50 μm is even more preferable. The thickness T of the sealant layer 22 22 When it is above the above lower limit value, the impact resistance of the film 1 for packaging can be further enhanced. The thickness T of the sealant layer 22 22 When it is below the above upper limit value, the flexibility of the film 1 for packaging is enhanced and handling becomes easier. The thickness T of the sealant layer 22 22 can be measured, for example, with a thickness gauge.

[0039] (Aluminum vapor deposition layer) The aluminum vapor deposition layer 24 has oxygen barrier properties, water vapor barrier properties, and light shielding properties. That is, the aluminum vapor deposition layer 24 in the present embodiment has a role of suppressing the transmission of oxygen, water vapor, ultraviolet rays, and visible light. In this embodiment, the aluminum vapor deposition layer 24 is formed on the sealant layer 22 instead of the base material 10. Therefore, by providing a printing layer on the base material 10, a predetermined appearance can be imparted to the packaging film 1 without being shielded by the aluminum vapor deposition layer 24. As a result, the appearance of the packaging film 1 can be made beautiful. In addition, in this embodiment, by using the aluminum vapor deposition layer 24 and the coating layer 14 in combination, the light shielding property of the packaging film 1 can be further enhanced, and deterioration of the contents of the package formed by bagging the packaging film 1 due to ultraviolet rays or the like can be suppressed.

[0040] The thickness T of the aluminum vapor deposition layer 24 24 is 20 to 100 nm, preferably 35 to 85 nm, and more preferably 50 to 70 nm. The thickness T of the aluminum vapor deposition layer 24 24 When it is equal to or greater than the above lower limit value, it is easier to further enhance the oxygen barrier property, water vapor barrier property, and light shielding property of the packaging film 1. The thickness T of the aluminum vapor deposition layer 24 24 When it is equal to or less than the above upper limit value, the occurrence of delamination due to cohesive failure can be suppressed. Therefore, a decrease in the impact resistance of the packaging film 1 can be suppressed. In addition, when the thickness T of the aluminum vapor deposition layer 24 24 is equal to or less than the above upper limit value, it is advantageous in terms of cost. The thickness T of the aluminum vapor deposition layer 24 24 can be measured, for example, by observing a cut surface obtained by cutting the packaging film 1 in the thickness direction with a microscope or the like.

[0041] ≪Method for manufacturing a packaging film≫ The method for manufacturing the packaging film 1 includes a step of obtaining the base layer 12 (base layer manufacturing step), a step of providing the coating layer 14 on the surface of the base layer 12 to obtain the base material 10 (coating step), a step of obtaining the sealant layer 22 (sealant layer manufacturing step), a step of providing the aluminum vapor deposition layer 24 on one side of the sealant layer 22 to obtain the sealant material 20 (sealant material manufacturing step), a step of laminating the base material 10 and the sealant material 20 via an adhesive to obtain a laminate (laminate manufacturing step), and a step of subjecting the laminate to a heat treatment (heat treatment step).

[0042] <Base layer manufacturing step> The method for obtaining the base layer 12 in the base layer manufacturing process is selected from conventionally known methods such as the inflation method, the T-die method, and the co-extrusion method according to the material, configuration, etc. of the base layer 12.

[0043] <Coating process> In the coating process, a coating layer 14 is provided on one surface of the base layer 12. The coating layer 14 is obtained by applying a coating agent containing titanium dioxide to one surface of the base layer 12 and drying it.

[0044] The coating agent contains titanium dioxide and a solvent. The content of titanium dioxide in the coating agent is preferably 10 to 50% by mass, more preferably 15 to 40% by mass, and even more preferably 20 to 30% by mass with respect to the total mass of the coating agent. When the content of titanium dioxide in the coating agent is at least the above lower limit value, the light shielding property can be further enhanced. When the content of titanium dioxide in the coating agent is at most the above upper limit value, it is easy to form a stable coating film. Examples of the solvent contained in the coating agent include propyl acetate (normal propyl acetate), ethyl acetate, isopropyl alcohol (IPA), ethanol, butyl acetate, methyl ethyl ketone, hexane, etc. Since the compatibility with titanium dioxide is good, the solvents contained in the coating agent are preferably propyl acetate, ethyl acetate, and isopropyl alcohol. These solvents may be used alone or in combination of two or more.

[0045] The coating agent may contain various resins in addition to titanium dioxide and the solvent. Examples of the various resins include chlorinated polypropylene (chlorinated PP), chlorinated polyolefin (chlorinated PO), nitrocellulose, etc. The coating agent can further enhance the stability of the coating film by containing various resins. For the purpose of imparting a predetermined appearance to the film 1 for packaging, a coating agent may be used as printing ink. The printing ink contains various resins and pigments of various colors described above. When the coating agent is used as printing ink, the coating layer 14 also serves as a printing layer.

[0046] The coating amount of the coating agent in the coating step is, for example, 1 to 30 g / m 2 is preferable, 2 to 25 g / m 2 is more preferable, and 3 to 20 g / m 2 is even more preferable. When the coating amount of the coating agent is within the above numerical range, it is easy to control the titanium dioxide content of the coating layer 14 within a desired range.

[0047] The method of applying the coating agent to the base layer 12 is not particularly limited, and for example, it may be applied using a brush or the like, or it may be applied using a spray or the like.

[0048] After applying the coating agent to the base layer 12, the temperature during drying is not particularly limited. For example, 30 to 60 °C is preferable, and 35 to 50 °C is more preferable. When the temperature during drying is equal to or higher than the above lower limit value, it is easier to further improve the stability of the coating film of the coating layer 14. When the temperature during drying is equal to or lower than the above upper limit value, it is easy to make the thickness T 14 of the coating layer 14 uniform. By providing the coating layer 14 on one surface of the base layer 12, the base material 10 is obtained.

[0049] <Sealant layer manufacturing process> The method for obtaining the sealant layer 22 in the sealant layer manufacturing process is selected from conventionally known methods such as the inflation method, the T-die method, and the coextrusion method according to the material and configuration of the sealant layer 22.

[0050] <Sealant material manufacturing process> In the sealant material manufacturing process, an aluminum vapor deposition layer 24 is provided on one side of the sealant layer 22. The method of providing the aluminum vapor deposition layer 24 on the sealant layer 22 is not particularly limited, and a conventionally known vacuum vapor deposition method can be applied (vapor deposition operation). In the vapor deposition operation, the degree of vacuum in the vapor deposition chamber is preferably, for example, 0.1 to 0.5 Pa. In the vapor deposition operation, the conveyance speed of the unstretched polypropylene film is preferably, for example, 100 to 400 m / min. By the vapor deposition operation, a sealant material 20 having an aluminum vapor deposition layer 24 formed on one side of the sealant layer 22 is obtained.

[0051] <Laminate manufacturing process> In the laminate manufacturing process, a laminate of the base material 10 and the sealant material 20 is manufactured. The method of laminating the base material 10 and the sealant material 20 in the laminate manufacturing process is selected from conventionally known methods such as the dry lamination method. In the dry lamination method, for example, an adhesive is applied to the surface of the aluminum vapor deposition layer 24 of the sealant material 20 to be laminated, the base material 10 and the sealant material 20 are laminated via the adhesive, and each layer is pressure-bonded and dried to obtain a laminate. The obtained laminate is wound up in a roll shape, for example. The adhesive may be applied to the coating layer 14 of the base material 10.

[0052] <Heat treatment process> After manufacturing the laminate as described above, in the heat treatment process, the laminate is subjected to heat treatment. By subjecting the laminate to heat treatment, the curing of the adhesive is promoted.

[0053] The temperature of the heat treatment is preferably, for example, 30 to 60°C, and more preferably 35 to 50°C. When the temperature of the heat treatment is equal to or higher than the above lower limit value, the curing of the adhesive is sufficiently promoted, and the adhesiveness between the base material 10 and the sealant material 20 can be further enhanced. When the temperature of the heat treatment is equal to or lower than the above upper limit value, damage to each layer constituting the laminate due to heat can be suppressed, and a decrease in the oxygen barrier property and water vapor barrier property of the packaging film 1 can be further suppressed.

[0054] The heat treatment time is preferably, for example, 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 longer than the above lower limit value, the curing of the adhesive is sufficiently promoted, and the adhesiveness between the base material 10 and the sealant material 20 can be further enhanced. When the heat treatment time is equal to or shorter than the above upper limit value, the productivity of the film 1 for packaging can be improved. The heat treatment of the laminate can be performed in a conventionally known constant temperature chamber or the like. In addition, the laminate subjected to this heat treatment and the laminate not subjected to this heat treatment can be discriminated, for example, by analyzing the curing state of the adhesives of both by FTIR or nuclear magnetic resonance method (NMR).

[0055] In addition to the above-described steps, the method for manufacturing the film for packaging may include a printing step of providing a printing layer (not shown) on the base material 10 for the purpose of imparting a predetermined appearance to the film for packaging. The printing step is not particularly limited, and various printing methods such as offset printing, gravure printing, flexographic printing, screen printing, and inkjet printing can be adopted.

[0056] ≪Package≫ The package of this embodiment is obtained by bagging the film 1 for packaging of this embodiment. Examples of the package include a bag formed by heat-sealing the sealant layers 22 of the film 1 for packaging. Examples of the form of the package include a gusseted bag, a three-side sealed bag, a four-side sealed bag, a gusset bag, a stand-up bag, and a bag with a chuck of these. Further, for example, the package includes a container body having an opening and a lid body made of the film 1 for packaging, the sealant layer 22 is brought into contact with the peripheral edge of the opening of the container body, and the film 1 for packaging is heat-sealed to the container body. In this case, polypropylene is preferable as the material of the container body from the viewpoint of easy recyclability.

[0057] As described above, since the film 1 for a package of the present embodiment includes the base material 10 in which the coating layer 14 containing titanium dioxide is formed on the base layer 12, it is excellent in water vapor barrier property and light shielding property. Since the film 1 for a package of the present embodiment includes the sealant material 20 in which the aluminum vapor deposition layer 24 is formed on the sealant layer 22, it is excellent in oxygen barrier property, water vapor barrier property, and light shielding property. Since the film 1 for a package of the present embodiment uses an isocyanate-based adhesive containing a polyester polyol having a carbon-carbon double bond and a compound having an isocyanate group, it is excellent in oxygen absorption property. Therefore, the film 1 for a package of the present embodiment is excellent in oxygen barrier property. Since the adhesive layer 30 of the film 1 for a package of the present embodiment contains an oxygen absorber, it is excellent in oxygen absorption property. Therefore, the film 1 for a package of the present embodiment is excellent in oxygen barrier property. The resins of the base material 10 and the sealant material 20 of the film 1 for a package of the present embodiment are both polypropylene. Thus, since the film 1 for a package of the present embodiment is a monomaterial (single material), it can be easily recycled. The package formed by bagging the film 1 for a package of the present embodiment has a sealant layer 22 excellent in heat sealability, so that the seal strength can be maintained and it is excellent in impact resistance. The package formed by bagging the film 1 for a package of the present embodiment can use the coating layer 14 also as a printing layer, so that a predetermined appearance can be imparted and the appearance can be made beautiful. The package formed by bagging the film 1 for a package of the present embodiment is a monomaterial, so that it can be easily recycled.

[0058] [Second Embodiment] ≪Film for Package≫ The film for a package according to the second embodiment of the present invention will be described with reference to the drawings. The same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted. The film 2 for the package shown in FIG. 2 is formed by laminating a base material 16, an adhesive layer 30, and a sealant material 20 in this order. That is, the film 2 for the package includes a base material 16, a sealant material 20 located on one surface of the base material 16, and an adhesive layer 30 located between the base material 16 and the sealant material 20.

[0059] The film 2 for the package of the present embodiment includes a base material 16 which is a biaxially stretched polypropylene film, and a sealant material 20 located on one surface of the base material 16, on which an aluminum vapor deposition layer 24 is formed on one side of a sealant layer 22 made of an unstretched polypropylene film. In the film 2 for the package of the present embodiment, the resin of the base material 16 and the resin of the sealant material 20 are of the same type (polypropylene). Therefore, when recovering the film 2 for the package of the present embodiment, it is not necessary to separately recover the base material 16 and the sealant material 20, and it can be easily recycled. The film 2 for the package of the present embodiment is different from the film 1 for the package of the first embodiment in that the base material does not have a coating layer.

[0060] The oxygen permeability of the film 2 for the package is the same as that of the film 1 for the package of the first embodiment. The light transmittance of the film 2 for the package is the same as that of the film 1 for the package of the first embodiment. The light transmittance of the film 2 for the package can be adjusted by the material and thickness of the base material 16, the content of the light-shielding inorganic substance, the thickness of the aluminum vapor deposition layer 24, and the combination thereof. The thickness T2 of the film 2 for the package is the same as the thickness T1 of the film 1 for the package of the first embodiment.

[0061] <Base material> The base material 16 is a biaxially stretched polypropylene film. The base material 16 contains polypropylene and titanium dioxide. By using a biaxially stretched polypropylene film as the base material 16, the water vapor barrier property of the film 2 for the package can be enhanced. This is presumably because the crystallinity of polypropylene can be increased by stretching the polypropylene film. Also, polypropylene has excellent dispersibility of titanium dioxide compared to other resins such as polyethylene terephthalate. Therefore, the light-shielding property of the film 2 for the package can be further enhanced. Examples of the polypropylene in the base material 16 include homopolypropylene, a copolymer of polypropylene containing about 10% by mass of polyethylene and polyethylene, block polypropylene, and the like. The base material 16 may contain 50% by mass or more of polypropylene. The base material 16 may be a single layer or a multilayer in which two or more layers are laminated.

[0062] The base material 16 contains titanium dioxide as a light-shielding inorganic substance. The film 2 for the package has excellent light-shielding property by having the base material 16. The content of titanium dioxide in the base material 16 is more than 5% by mass and less than 50% by mass with respect to the total mass of the base material 16, preferably 10% by mass or more and 45% by mass or less, and more preferably 15% by mass or more and 40% by mass or less. When the content of titanium dioxide exceeds the above lower limit value, the light-shielding property of the film 2 for the package can be further enhanced. When the content of titanium dioxide is less than the above upper limit value, the strength of the base material 16 can be further increased, and a decrease in the impact resistance of the film 2 for the package can be suppressed.

[0063] The light-shielding inorganic substance contained in the base material 16 is titanium dioxide. When, for example, calcium carbonate or zinc oxide is used as the light-shielding inorganic substance, it is difficult to obtain sufficient scattering intensity and the light-shielding property cannot be enhanced.

[0064] The average primary particle diameter of the titanium dioxide contained in the base material 16 is the same as that of the titanium dioxide contained in the coating layer 14 in the first embodiment.

[0065] <<Method for Manufacturing Film for Package>> The method for manufacturing the film 2 for package includes a step of obtaining a base material 16 (base material manufacturing step), a step of obtaining a sealant layer 22 (sealant layer manufacturing step), a step of providing an aluminum vapor deposition layer 24 on one side of the sealant layer 22 to obtain a sealant material 20 (sealant material manufacturing step), a step of laminating the base material 16 and the sealant material 20 via an adhesive to obtain a laminate (laminate manufacturing step), and a step of subjecting the laminate to a heat treatment (heat treatment step).

[0066] <<Base Material Manufacturing Step>> In the base material manufacturing step, a base material 16 containing titanium dioxide is obtained. The resin composition serving as the raw material of the base material 16 is formed by a conventionally known method such as an inflation method, a T-die method, a coextrusion method, etc. At this time, the base material 16 is obtained by forming the resin composition while stretching in the MD direction and the TD direction. The resin composition contains polypropylene and titanium dioxide. Examples of the polypropylene in the resin composition include homopolypropylene, a copolymer of polypropylene and polyethylene containing about 10% by mass of polyethylene, block polypropylene, etc. The resin composition may contain 50% by mass or more of polypropylene.

[0067] The content of titanium dioxide in the resin composition is more than 5% by mass and less than 50% by mass with respect to the total mass of the resin composition, preferably 10% by mass or more and 45% by mass or less, and more preferably 15% by mass or more and 40% by mass or less. When the content of titanium dioxide exceeds the above lower limit value, the light shielding property of the film 2 for package can be further enhanced. When the content of titanium dioxide is less than the above upper limit value, the strength of the base material 12 can be further increased, and a decrease in the impact resistance of the film 2 for package can be suppressed.

[0068] The resin composition may contain other components in addition to polypropylene and titanium dioxide. Examples of other components include additives such as nucleating agents, flame retardants, lubricants, etc. generally used in polypropylene films.

[0069] The process for manufacturing the sealant layer, the process for manufacturing the sealant material, the process for manufacturing the laminate, and the heat treatment process are the same as those for the method of manufacturing the film 1 for the package in the first embodiment.

[0070] ≪Package≫ The package of this embodiment is formed by bagging the film 2 for the package of this embodiment. Examples of the package include, for example, a bag formed by heat-sealing the sealant layers 22 of the film 2 for the package. Examples of the form of the package include, for example, a gusseted bag, a three-side sealed bag, a four-side sealed bag, a gusset bag, a stand-up bag, and these bags with zippers. Also, for example, as the package, there is a container having a container body with an opening and a lid made of the film 2 for the package, with the sealant layer 22 in contact with the peripheral edge of the opening of the container body, and the film 2 for the package is heat-sealed to the container body. In this case, from the viewpoint of easy recyclability, polypropylene is preferable as the material of the container body.

[0071] As described above, since the film 2 for the package of this embodiment includes the base material 16 containing titanium dioxide, it has excellent water vapor barrier properties and light-shielding properties. In the film 2 for the package of this embodiment, the resins of the base material 16 and the sealant material 20 are both polypropylene. Thus, since the film 2 for the package of this embodiment is a single material, it can be easily recycled. A printed layer may be provided on the base material 16 of the package formed by bagging the film 2 for the package of this embodiment. Therefore, a predetermined appearance can be imparted, and the appearance can be made beautiful. The package formed by bagging the film 2 for the package of this embodiment is a single material, so it can be easily recycled.

[0072] [Other Embodiments] In the above-described first embodiment, the coating layer 14 is formed on the surface of the base layer 12 facing the sealing material 20. However, the present invention is not limited to this, and the coating layer may be formed on the surface opposite to the surface of the base layer facing the sealing material. However, from the viewpoint of suppressing the adhesion of dirt to the surface of the base material, the coating layer is preferably formed on the surface of the base layer facing the sealing material. In the above-described first embodiment, the coating layer 14 is formed on one side of the base layer 12. However, the present invention is not limited to this, and the coating layer may be formed on both sides of the base layer. In the above-described second embodiment, the base material 16 does not include a coating layer. However, the present invention is not limited to this, and the base material 16 and the coating layer may be used in combination.

Examples

[0073] Hereinafter, the present invention will be described 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.

[0074] [Materials Used] ≪Base Material≫ ·OPP: Biaxially oriented polypropylene film, Pyren (registered trademark) film - OT (product name), manufactured by Toyobo Co., Ltd., thickness 30 μm. ·OPP: Biaxially oriented polypropylene film, Pyren (registered trademark) film - OT (product name), manufactured by Toyobo Co., Ltd., thickness 20 μm. ·PET: Polyethylene terephthalate film, Toyobo ester film (product name), manufactured by Toyobo Co., Ltd., thickness 38 μm.

[0075] ≪Coating Layer≫ <Light-Shielding Inorganic Substance> ·TiO2: Titanium dioxide, Titanium Oxide (product name), manufactured by Sakai Chemical Industry Co., Ltd., average primary particle diameter (average particle diameter of 100 primary particles) 200 nm. · CaCO3: Calcium carbonate, Neolite (trade name), manufactured by Takehara Chemical Industry Co., Ltd., average primary particle diameter (average particle diameter of 100 primary particles) 80 nm. · ZnO: Zinc oxide, one type (trade name), manufactured by Sakai Chemical Industry Co., Ltd., average primary particle diameter (average particle diameter of 100 primary particles) 750 nm.

[0076] <Coating agent> (Solvent) · Solvent A: Propyl acetate, manufactured by Sankyo Chemical Co., Ltd. · Solvent B: Ethyl acetate, manufactured by Sankyo Chemical Co., Ltd. · Solvent C: Isopropyl alcohol, manufactured by Sankyo Chemical Co., Ltd. (Resin) · Resin a: Chlorinated PP, Hardlen (registered trademark) (trade name), manufactured by Toyobo Co., Ltd. · Resin b: Chlorinated PO, Superclone (registered trademark) (trade name), manufactured by Nippon Paper Industries Co., Ltd. · Resin c: Nitrocellulose, industrial nitrocellulose (trade name), manufactured by Taihei Chemical Products Co., Ltd. (Coating agents used in each example) · Example 1: A liquid prepared by mixing 30% by mass of titanium dioxide in Solvent D (an equal mixture of Solvent A, Solvent B, and Solvent C). · Example 2: A liquid prepared by mixing 15% by mass of titanium dioxide in Solvent D. · Examples 3 - 6: A liquid prepared by mixing Solvent D, Resin a, and titanium dioxide in a mass ratio of 6:2:2. · Example 7: A liquid prepared by mixing Solvent D, Resin b, and titanium dioxide in a mass ratio of 6:2:2. · Example 8: A liquid prepared by mixing Solvent D, Resin c, and titanium dioxide in a mass ratio of 6:2:2. · Comparative Example 1: A liquid prepared by mixing Solvent D, Resin a, and calcium carbonate in a mass ratio of 6:2:2. · Comparative Example 2: A liquid prepared by mixing Solvent D, Resin a, and zinc oxide in a mass ratio of 6:2:2. · Comparative Example 3: A liquid prepared by mixing 7% by mass of titanium dioxide in Solvent D. · Comparative Example 4: A liquid prepared by mixing 90% by mass of titanium dioxide in Solvent D. · Comparative Examples 5 to 7: A liquid prepared by mixing Solvent D, Resin a, and titanium dioxide in a mass ratio of 6:2:2.

[0077] ≪Sealant Material≫ <Sealant Layer> · CPP: Unstretched polypropylene film, Taiko (registered trademark) FC, manufactured by Futamura Chemical Co., Ltd., thickness 30 μm. · CPP: Unstretched polypropylene film, Pyren (registered trademark) Film - CT (product name), manufactured by Toyobo Co., Ltd., thickness 20 μm. <Aluminum Evaporation Layer> (Evaporation Conditions) · Name of evaporation device: Winding type vacuum evaporation device EWA series (product name), manufactured by ULVAC, Inc. · Evaporation source: Aluminum. · Vacuum degree inside the evaporation chamber: 0.2 Pa. · Conveying speed of the film: 200 m / min.

[0078] ≪Adhesive Layer≫ <Main Agent> · Saturated polyester: Manufactured by Nippon Gohsei Co., Ltd. · Phthalic anhydride: Manufactured by Junsei Chemical Co., Ltd. <Hardening Agent> · IPDI: Isophorone diisocyanate, Takenate (registered trademark), manufactured by Mitsui Chemicals, Inc. · TDI: Toluene diisocyanate, Takenate (registered trademark), manufactured by Mitsui Chemicals, Inc. <Oxygen Absorbent> · Conjugated diene: Conjugated diene polymer cyclized product (polyisoprene cyclized product). · Transition metal: Transition metal salt, cobalt neodecanoate, manufactured by Nippon Chemical Industry Co., Ltd.

[0079] [Examples 1 to 8, Comparative Examples 1 to 7] The coating agent of each example was applied by spraying on one side of the base layer shown in Table 1, and then dried at 80 °C for 1 hour to form a coating layer with the film thickness shown in Table 1, thereby obtaining a base material. An adhesive containing the oxygen absorber shown in Table 1 was applied to the aluminum vapor deposition layer of the sealant material on which the aluminum vapor deposition layer with the film thickness shown in Table 1 was formed, and the surface of the base material on which the coating layer was formed was laminated to obtain a laminate. This laminate was heat-treated at 40 °C for 72 hours to produce a packaging film according to the configurations of Examples 1 to 8 and Comparative Examples 1 to 7. In the table, "-" indicates that no oxygen absorber is contained.

[0080] [Examples 9 to 10, Comparative Examples 8 to 11] An adhesive containing the oxygen absorber shown in Table 3 was applied to the aluminum vapor deposition layer of the sealant material on which an aluminum vapor deposition layer with a thickness of 60 nm was formed, and the base material shown in Table 3 was laminated to obtain a laminate. This laminate was heat-treated at 40 °C for 72 hours to produce a packaging film according to the configurations of Examples 9 to 10 and Comparative Examples 8 to 11.

[0081] [Evaluation Method] <Evaluation of Oxygen Barrier Property> For the packaging films obtained in each example, the oxygen permeability was measured according to the test method for oxygen gas permeability by the electrolytic sensor method 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 Tables 2 and 4. 《Evaluation Criteria》 ◎: Oxygen permeability 2.0 mL / (m 2 ·day) or less. ○: Oxygen permeability exceeds 2.0 mL / (m 2 ·day) and is 4.0 mL / (m 2 ·day) or less. ×: Oxygen permeability exceeds 4.0 mL / (m 2 ·day).

[0082] <Evaluation of Water Vapor Barrier Property> For the base materials of each example, the water vapor transmission rate was measured under Test Condition 1 described in Table A.1 in accordance with the test method described in the humidity 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 Tables 2 and 4. 《Evaluation Criteria》 ◎: Water vapor transmission rate is 2.0 g / (m 2 ·day) or less. ○: Water vapor transmission rate exceeds 2.0 g / (m 2 ·day) and is 4.0 g / (m 2 ·day) or less. ×: Water vapor transmission rate exceeds 4.0 g / (m 2 ·day).

[0083] <Evaluation of Light Shielding Property> For the film for packaging obtained in each example, the light transmittance of visible light with a wavelength of 450 nm was measured using an ultraviolet-visible spectrophotometer (manufactured by Shimadzu Corporation, UV-2600i), and the light shielding property was evaluated based on the following evaluation criteria. The results are shown in Tables 2 and 4. 《Evaluation Criteria》 ◎: Light transmittance is 4% or less. ○: Light transmittance exceeds 4% and is 10% or less. △: Light transmittance exceeds 10% and is 20% or less. ×: Light transmittance exceeds 20%.

[0084] <Evaluation of Impact Resistance> The sealant layer of the film for packaging obtained in each example was heat-sealed (sealing temperature: 180 °C, sealing time: 1 second, sealing pressure: 3.5 kg / cm 2 , sealing width: 10 mm) to produce a three-side sealed bag (flat bag) of 130 mm × 170 mm. This flat bag was filled with 180 mL of water, and the opening was heat-sealed under the same conditions as above to obtain a sample for evaluation. This sample for evaluation was dropped vertically from a height of 1.2 m onto a concrete surface, and this operation was repeated 3 times (drop strength test). Among the 10 samples for evaluation, the number of samples (number of broken bags) in which leakage of the contents was observed was counted, and the impact resistance was evaluated based on the following evaluation criteria. The results are shown in Tables 2 and 4. 《Evaluation Criteria》 ◎: Number of broken bags is 0. ○: The number of broken bags is 1 or 2. ×: The number of broken bags is 3 or more.

[0085] <Overall Evaluation> Based on the evaluation results of the above evaluations of oxygen barrier property, water vapor barrier property, light shielding property, and impact resistance, the films for packages of each example were comprehensively evaluated according to the following evaluation criteria. The results are shown in Tables 2 and 4. Those with an overall evaluation of "◎" or "○" were considered qualified. 《Evaluation Criteria》 ◎: All evaluation results are "◎". ○: There is one or more "○" in the evaluation results, and there is no "×" in the evaluation results. ×: There is one or more "×" in the evaluation results.

[0086]

Table 1

[0087]

Table 2

[0088]

Table 3

[0089]

Table 4

[0090] As shown in Tables 1 to 4, the films for packages and the packages of Examples 1 to 10 to which the present invention was applied were confirmed to have an overall evaluation of "◎" or "○" and to be excellent in oxygen barrier property, water vapor barrier property, light shielding property, and impact resistance. On the other hand, in Comparative Examples 1 to 2 where the coating layer does not contain titanium dioxide, the light transmittance was high and the evaluation of light shielding property was "×". In Comparative Examples 3 to 4 where the content of titanium dioxide was outside the scope of the present invention, the light transmittance was high and the evaluation of light shielding property was "×". In Comparative Example 5 where the adhesive layer does not contain an oxygen absorber, the oxygen permeability was high and the evaluation of oxygen barrier property was "×". In addition, the number of broken bags was large and the evaluation of impact resistance was "×". In Comparative Example 6 where PET was used for the base layer, the water vapor permeability was high and the evaluation of water vapor barrier property was "×". In addition, the light transmittance was high and the evaluation of light shielding property was "×". In Comparative Example 7 where the film thickness of the aluminum vapor deposition layer was outside the scope of the present invention, the number of broken bags was large and the evaluation of impact resistance was "×". In Comparative Example 8 where the content of titanium dioxide was outside the scope of the present invention, the light transmittance was high and the evaluation of light shielding property was "×". In Comparative Examples 9 to 10 where the base material does not contain titanium dioxide, the light transmittance was high and the evaluation of light shielding property was "×". In Comparative Example 11 where PET was used for the base material, the water vapor permeability was high and the evaluation of water vapor barrier property was "×". In addition, the light transmittance was high and the evaluation of light shielding property was "×".

[0091] From the above results, it was confirmed that by applying the present invention, excellent oxygen barrier property, water vapor barrier property, light shielding property and impact resistance can be obtained.

Explanation of Signs

[0092] 1,2 Film for packaging body 10,16 Base material 12 Base layer 14 Coating layer 20 Sealing material 22 Sealing layer 24 Aluminum vapor deposition layer 30 Adhesive layer

Claims

1. On the surface of a base layer made of a biaxially stretched polypropylene film, a coating layer containing 0.5 to 5.0 g / m of titanium dioxide is formed, and ２ a base material, a sealant material located on one surface of the base material, on one side of a sealant layer made of an unstretched polypropylene film, an aluminum vapor deposition layer is formed, and an adhesive layer located between the base material and the sealant material, and the aluminum vapor deposition layer faces the base material, the thickness of the aluminum vapor 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 film for a package.

2. a base material which is a biaxially stretched polypropylene film, a sealant material located on one surface of the base material, on one side of a sealant layer made of an unstretched polypropylene film, an aluminum vapor deposition layer is formed, and an adhesive layer located between the base material and the sealant material, and the base material contains titanium dioxide, the content of the titanium dioxide is more than 5% by mass and less than 50% by mass based on the total mass of the base material, the aluminum vapor deposition layer faces the base material, the thickness of the aluminum vapor 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 oxygen absorber content is 1% by mass or more with respect to the total mass of the isocyanate-based adhesive, a film for a package.

3. The coating layer faces the surface of the aluminum vapor deposition layer, the film for a package according to Claim 1.

4. The thickness of the coating layer is 0.5 to 5.0 μm, the film for a package according to Claim 1.

5. The oxygen absorber content is 1 to 10% by mass with respect to the total mass of the isocyanate-based adhesive, the film for a package according to any one of Claims 1 to 4.

6. The average primary particle diameter of the titanium dioxide is 100 to 500 nm, the film for a package according to any one of Claims 1 to 5.

7. The oxygen absorber is one or more selected from a conjugated diene polymer cyclized product and a transition metal salt, the film for a package according to any one of Claims 1 to 6.

8. A package in which the film for a package according to any one of Claims 1 to 7 is formed into a bag.

Images