JP7123820B2 - LAMINATED FILM, PACKAGE, AND LAMINATED FILM MANUFACTURING METHOD - Google Patents

Description

TECHNICAL FIELD The present invention relates to a laminated film, a package, and a method for producing a laminated film.

In recent years, there has been an increase in the number of occasions when foods and medicines are housed in plastic packages. Foods and medicines can be degraded by moisture and oxygen, so in order to prolong the shelf life of the food and medicines contained in them, packages containing them are required to have high water vapor barrier properties and oxygen barrier properties. .
In addition, in recent years, there has been an increase in the number of consumers who seek more convenience, and the package can be easily opened by hand without using scissors or knives when opening the package, and can be opened straight. (packaging body having easy-open property) is increasing in demand.

As an easy-to-open package, for example, Patent Document 1 proposes a package film including a base layer having a layer of biaxially oriented polypropylene and an oxygen barrier layer, and a sealant layer. there is
In the packaging film of Patent Literature 1, orientation is imparted to the film itself to improve easy-openability.

JP 2017-24377 A

However, when a means for imparting orientation to the film itself is applied as in the film for packaging of Patent Document 1, it is difficult to tear the film straight, and the easy-openability is not sufficient.
When a means for physically forming a tear line is applied, the easy-open property is sufficiently exhibited, but the surface of the film is damaged, so there is a possibility that the water vapor barrier property and the oxygen barrier property are lowered. In addition, there is a possibility that tear marks of the film called "whiskers" are generated at the places where the package is torn, and the appearance of the film is spoiled.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a laminated film, a packaging body, and a method for producing a laminated film that are excellent in appearance, water vapor barrier properties, and oxygen barrier properties after being cleaved, and are also excellent in easy opening properties. and

As a result of extensive studies, the present inventors have found that a laminated film having the following structure can solve the above problems.
That is, the packaging film of the present invention has the following configuration.
[1] A substrate having a straight cutting property, and a sealant material located on one surface of the substrate, the sealant material having an aluminum vapor deposition film, and a gap between the substrate and the aluminum vapor deposition film. Having an adhesive layer therebetween, the adhesive layer is a cured product of an adhesive containing a polyester polyol having a carbon-carbon double bond and a compound having an isocyanate group, and unreacted in the adhesive layer is 3 to 30 mol%, the thickness of the adhesive layer is 1.5 to 5.0 μm, and the sealant material contains The elongation in the MD direction is 450 to 1000%, the elongation in the TD direction of the sealant material is 500 to 1100%, the tensile modulus of elasticity in the MD direction of the sealant material is 700 to 1200 MPa, and the sealant material A laminated film having a tensile modulus of elasticity in the TD direction of 700 to 1200 MPa.
[2] The laminated film according to [1], wherein a tear line is formed on the other surface of the base material.
[3] The laminated film according to [1] or [2], wherein the glass transition temperature of the adhesive layer is -10°C or higher.
[4] A package made of the laminated film according to any one of [1] to [3].

[5] The method for producing a laminated film according to any one of [1] to [3], wherein the base material and the aluminum vapor-deposited film are laminated via the adhesive. Method.

The laminated film of the present invention is excellent in appearance, water vapor barrier properties and oxygen barrier properties after being cleaved, and is also excellent in ease of opening.

1 is a cross-sectional view of a laminated film according to a first embodiment of the invention; FIG. FIG. 4 is a cross-sectional view of a laminated film according to a second embodiment of the invention;

The laminated film of the present invention comprises a substrate and a sealant material located on one side of the substrate.
Furthermore, the sealant material of the laminated film of the present invention has an aluminum deposition film. The laminated film of the present invention has an adhesive layer between the substrate and the aluminum deposited film.
Hereinafter, the laminated film of the present invention will be described with reference to embodiments.

[First embodiment]
≪Laminated film≫
A laminated film according to a first embodiment of the present invention will be described with reference to the drawings.
The laminated film 1 of FIG. 1 is obtained by laminating a substrate 10, an adhesive layer 30, and a sealant material 20 in this order. That is, the laminated film 1 includes a substrate 10 , a sealant material 20 located on one side A of the substrate 10 , and an adhesive layer 30 located between the substrate 10 and the sealant material 20 . The sealant material 20 has a sealant layer 22 and an aluminum deposited film 24 . The adhesive layer 30 is positioned between the substrate 10 and the aluminum deposition film 24 .

The water vapor permeability of the laminated film 1 is, for example, preferably 2.0 g/(m ² ·day) or less, more preferably 1.0 g/(m ² ·day) or less, and 0.5 g/(m ² ·day). More preferred are: When the water vapor transmission rate of the laminated film 1 is equal to or less than the above upper limit, the intrusion of moisture from the outside of the package can be sufficiently suppressed, and the contents are less likely to deteriorate and more difficult to deteriorate. That is, the steam barrier property of the laminated film 1 can be further enhanced.
Incidentally, the water vapor transmission rate in the present invention is a value determined by the humidity sensor method of JIS K7129:2008.
The water vapor transmission rate of the laminated film 1 can be adjusted by the material and thickness of the substrate 10, the thickness of the aluminum deposition film 24, the material and thickness of the sealant layer 22, and combinations thereof.

The oxygen permeability of the laminated film 1 is preferably 2.0 cm ³ /(m ² ·day · atm) or less, more preferably 1.0 cm ³ /(m ² ·day · atm) or less, and 0.5 cm ³ /( m ² ·day·atm) or less is more preferable. When the oxygen permeability of the laminated film 1 is equal to or less than the above upper limit value, the intrusion of oxygen from the outside of the package can be sufficiently suppressed, and the contents are less likely to deteriorate and more difficult to deteriorate. That is, the oxygen barrier property of the laminated film 1 can be further enhanced.
The oxygen permeability in the present invention is a value determined by the electric field sensor method of JIS K7126-2:2006.
The oxygen permeability of the laminated film 1 can be adjusted by the material and thickness of the substrate 10, the thickness of the aluminum deposition film 24, the material and thickness of the sealant layer 22, and combinations thereof.

The thickness T1 of the laminated film ₁ is not particularly limited, but is preferably 35 to 250 μm, more preferably 40 to 200 μm, even more preferably 50 to 150 μm. When the thickness T1 of the laminate film ₁ is at least the above lower limit, the vapor barrier properties and oxygen barrier properties of the laminate film 1 can be further enhanced. When the thickness T1 of the laminated film ₁ is equal to or less than the above upper limit, the easy-openability of the laminated film 1 can be further enhanced.
The thickness T1 of the laminated film ₁ can be measured with, for example, a thickness gauge.

<Base material>
The base material 10 has straight cutability. Examples of the base material 10 include a resin film having straight cuttability. In the present specification, the term "having straight cutability" means that when the base material 10 is torn, the difference between the position of the cut end at the beginning of tearing and the position of the cut end when the tear propagation reaches 100 mm (perpendicular to the tearing direction direction) is 10 mm or less.
Resin films include polyethylene terephthalate (PET), biaxially oriented PET, polyester films such as polybutylene terephthalate (PBT), polypropylene (PP), biaxially oriented polypropylene (OPP), non-oriented polypropylene (CPP), high density Examples include polyolefin films such as polyethylene (HDPE) and medium density polyethylene (MDPE), polyamide (PA) films such as biaxially oriented nylon (ONY), and laminates thereof. Among them, PET, biaxially stretched PET, PP, OPP and PA are preferred, and biaxially stretched PET and OPP are more preferred.
Examples of the laminate include a laminate of the resin films described above.
The base material 10 may be printed on its surface or between layers.

The base material 10 has an orientation degree α in the MD direction (flow direction when manufacturing a film) that is preferably more than 1.0 and 3.5 or less, more preferably 1.1 to 3.2, and 1.2 to 3.5. 0 is more preferred. When the degree of orientation α is at least the above lower limit, the easy-openability can be further enhanced. When the degree of orientation α is equal to or less than the above upper limit, it is easy to suppress the generation of whiskers when the package is opened. That is, the appearance of the package after being opened can be improved.
The base material 10 has an orientation degree β in the TD direction (direction perpendicular to the MD direction) that is preferably more than 1.0 and 3.5 or less, more preferably 1.1 to 3.2, and more preferably 1.2 to 3.0. More preferred. When the degree of orientation β is equal to or higher than the above lower limit, the easy-openability can be further enhanced. When the degree of orientation β is equal to or less than the above upper limit, it is easy to suppress the generation of whiskers when the package is opened. That is, the appearance of the package after being opened can be improved.
The ratio represented by the orientation degree α/orientation degree β of the substrate 10 (hereinafter sometimes referred to as the α/β ratio) is preferably 0.5 to 2.0, more preferably 0.5 to 1.5. . When the α/β ratio is within the above numerical range, the easy-openability can be further enhanced. In particular, when the laminated film 1 is made into a bag to form a package, the linear cuttability can be further enhanced. That is, it becomes easier to open the package in the intended direction.
The easy-open property of the laminated film 1 is affected by the α/β ratio of the substrate 10 . In particular, when a biaxially stretched resin film is used as the substrate 10, this effect becomes stronger.

The degree of orientation α and the degree of orientation β are calculated from values measured by an infrared dichroism method.
The degree of orientation is measured by a transmission method using an infrared spectrophotometer with linearly polarized light whose electric field oscillates only in a fixed direction.
As a measurement method, first, the background (BKG) measurement is performed with the installation angle of the polarizer set to 0 ° (the direction of the electric field is vertical), and then the stretching direction of the sample is aligned with the longitudinal direction, and the absorbance is measured ( At this time, the direction of polarization and the direction of the stretching axis are parallel.). The obtained value is defined as the absorbance "A//".
Next, the angle of the sample is rotated by 90°, and the absorbance is measured with the stretching axis of the sample perpendicular to the polarization direction. The obtained value is defined as the absorbance "A⊥".
The absorbance ratio ([A//]/[A⊥]) of the two absorbances A// and A⊥ obtained with polarized light parallel to and perpendicular to the stretching axis of the sample is defined as the degree of orientation.

A tear line may be formed on the other surface B of the substrate 10 . The rupture line is a linear or perforated cut, and is formed by subjecting the other surface B of the base material 10 to cutting or the like. Since the tear line is formed, the laminated film 1 can be easily torn without using a cutting tool such as scissors. In addition, since the tear line is formed, the straight cutting property of the substrate 10 can be further enhanced. In addition, the linear cut means that a linear groove is continuously formed in the base material 10 with a slight thickness left. A perforated cut means that slits or grooves are continuously formed in the substrate 10 at predetermined intervals.

The tear line is formed in order to enhance the easy-opening property of the laminated film 1 . From the viewpoint of enhancing the easy-openability of the laminated film 1, the tear line is preferably formed to a depth of at least about half the thickness T10 of the base material ₁₀ , and penetrates the base material 10 to form the adhesive layer 30. or penetrate the adhesive layer 30 .
The maximum depth of the tear line is, for example, preferably 20 to 80%, more preferably 30 to 70%, even more preferably 40 to 60% of the thickness T1 of the laminated film ₁ . When the maximum depth of the tear line is at least the above lower limit, the easy-openability of the laminated film 1 can be further enhanced. When the maximum depth of the tear line is equal to or less than the above upper limit, the vapor barrier properties and oxygen barrier properties of the laminated film 1 can be further enhanced.
The maximum depth of the tear line can be measured, for example, by observing a cut surface obtained by cutting the laminated film 1 in the thickness direction at the position where the tear line is formed, with a microscope or the like.

The thickness T ₁₀ of the base material 10 is determined in consideration of the material, configuration, etc., and is preferably 5 to 100 μm, more preferably 10 to 50 μm. When the thickness T10 of the base material ₁₀ is at least the above lower limit, the vapor barrier properties and oxygen barrier properties of the laminated film 1 can be further enhanced. When the thickness T10 of the base material ₁₀ is equal to or less than the above upper limit value, the easy-opening property of the laminated film 1 can be further enhanced.
The thickness of the base material 10 can be measured with a thickness gauge, for example.

<Sealant material>
A sealant material 20 is located on one side A of the substrate 10 . The sealant material 20 has a sealant layer 22 and an aluminum deposited film 24 . The aluminum deposition film 24 is located on one surface C of the sealant layer 22 . An adhesive layer 30 is positioned between the base material 10 and the aluminum deposited film 24 , and the sealant material 20 is laminated on one surface A of the base material 10 with the adhesive layer 30 interposed therebetween.

The MD elongation of the sealant material 20 is 450 to 1000%, preferably 450 to 800%, more preferably 500 to 650%. When the elongation in the MD direction of the sealant material 20 is equal to or higher than the above lower limit, the strength of the laminated film 1 can be further increased. When the elongation in the MD direction of the sealant material 20 is equal to or less than the above upper limit, it is easy to suppress the generation of whiskers when the laminated film 1 is cleaved. That is, the appearance of the laminated film 1 after being cleaved can be improved.
The MD elongation of the sealant material 20 can be measured according to the test method described in JIS K7127:1999. The elongation of the sealant material 20 in the MD direction is obtained by dividing the increase in the distance between the gauge lines in the MD direction (mm) of the test piece by the distance between the gauge lines (mm) of the test piece and multiplying by 100 (% ).
The elongation of the sealant material 20 in the MD direction can be adjusted by the thickness of the aluminum deposition film 24, the material and thickness of the sealant layer 22, and a combination thereof.

The elongation of the sealant material 20 in the TD direction is 500 to 1100%, preferably 500 to 900%, more preferably 550 to 750%. When the elongation in the TD direction of the sealant material 20 is equal to or higher than the above lower limit, the strength of the laminated film 1 can be further increased. When the elongation in the TD direction of the sealant material 20 is equal to or less than the above upper limit, it is easy to suppress the generation of whiskers when the laminated film 1 is cleaved. That is, the appearance of the laminated film 1 after being cleaved can be improved.
The elongation of the sealant material 20 in the TD direction can be measured in the same manner as the elongation of the sealant material 20 in the MD direction. The elongation in the TD direction of the sealant material 20 is obtained by dividing the increase in the distance between the gauge lines in the TD direction (mm) of the test piece by the distance between the gauge lines (mm) of the test piece and multiplying by 100 (% ).
The elongation in the TD direction of the sealant material 20 can be adjusted by the thickness of the aluminum deposition film 24, the material and thickness of the sealant layer 22, and a combination thereof.

The tensile elastic modulus of the sealant material 20 in the MD direction is 700 to 1200 MPa, preferably 800 to 1100 MPa, more preferably 900 to 1000 MPa. When the tensile modulus of elasticity in the MD direction of the sealant material 20 is equal to or higher than the above lower limit, the straight cuttability of the laminated film 1 can be further enhanced. When the tensile modulus of elasticity in the MD direction of the sealant material 20 is equal to or less than the above upper limit, it is easy to suppress the generation of whiskers when the laminated film 1 is cleaved. That is, the appearance of the laminated film 1 after being cleaved can be improved.
The tensile modulus of elasticity in the MD direction of the sealant material 20 can be measured according to the test method described in JIS K7127:1999.
The tensile elastic modulus of the sealant material 20 in the MD direction can be adjusted by the thickness of the aluminum deposition film 24, the material and thickness of the sealant layer 22, and a combination thereof.

The tensile elastic modulus of the sealant material 20 in the TD direction is the same as the tensile elastic modulus of the sealant material 20 in the MD direction.
The tensile modulus of elasticity in the TD direction of the sealant material 20 can be measured in the same manner as the tensile modulus of elasticity in the MD direction of the sealant material 20 .
The tensile elastic modulus of the sealant material 20 in the TD direction can be adjusted by the thickness of the aluminum deposition film 24, the material and thickness of the sealant layer 22, and a combination thereof.

The thickness T ₂₀ of the sealant material 20 is determined in consideration of the material, structure, etc., and is preferably 5 to 150 μm, more preferably 5 to 100 μm, and even more preferably 10 to 50 μm. When the thickness T20 of the sealant material ₂₀ is at least the above lower limit, the vapor barrier properties and oxygen barrier properties of the laminated film 1 can be further enhanced. When the thickness T20 of the sealant material ₂₀ is equal to or less than the above upper limit value, the easy-opening property of the laminated film 1 can be further enhanced.
The thickness T20 of the sealant material ₂₀ can be measured, for example, with a thickness gauge.

(sealant layer)
The sealant layer 22 enhances the sealing properties of the laminated film 1 .
Examples of the resin constituting the sealant layer 22 include low-density polyethylene (LDPE), linear LDPE (LLDPE), MDPE, HDPE, polyolefins such as CPP, ethylene-vinyl alcohol polymer (EVOH), ethylene-vinyl acetate copolymer. polymer (EVA), ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), ethylene-ethyl acrylate copolymer (EEA), ionomer and the like. Among these, HDPE and CPP are preferable, and CPP is more preferable, from the viewpoint of excellent water vapor barrier properties. These resins may be used individually by 1 type, and may use 2 or more types together.

The thickness T ₂₂ of the sealant layer 22 is determined in consideration of the material and the like, and is preferably 5 to 100 μm, more preferably 5 to 90 μm, and even more preferably 10 to 50 μm. When the thickness T22 of the sealant layer ₂₂ is at least the above lower limit, the sealing property of the laminated film 1 can be further enhanced. When the thickness T22 of the sealant layer ₂₂ is equal to or less than the above upper limit, the easy-opening property of the laminated film 1 can be further enhanced.
The thickness T22 of the sealant layer ₂₂ can be measured, for example, with a thickness gauge.

(aluminum deposition film)
The aluminum deposition film 24 has water vapor barrier properties and oxygen barrier properties. That is, the aluminum deposition film 24 in this embodiment has a role of suppressing permeation of water vapor and oxygen.
In this embodiment, the aluminum deposition film 24 is formed on the sealant layer 22 instead of the base material 10 . Therefore, even if tear lines are formed in the base material 10 and the adhesive layer 30 , the vapor barrier properties and oxygen barrier properties of the laminated film 1 can be maintained by the aluminum deposition film 24 .
In addition, by laminating the sealant material 20 having the aluminum deposition film 24 and the base material 10 having easy-opening property, it is possible to easily produce the laminated film 1 having excellent water vapor barrier property and oxygen barrier property and excellent easy-opening property. and can be obtained inexpensively.

The thickness T ₂₄ of the aluminum deposition film 24 is preferably, for example, 30-70 nm, more preferably 30-50 nm. When the thickness T24 of the aluminum deposition film ₂₄ is equal to or greater than the above lower limit, deterioration of the water vapor barrier property and the oxygen barrier property can be suppressed. That is, when the laminated film 1 is used as a package, the contents are less likely to deteriorate, and the contents are less likely to deteriorate. When the thickness T24 of the aluminum deposition film ₂₄ is equal to or less than the above upper limit value, the easy-opening property of the laminated film 1 can be further enhanced.
The thickness T24 of the aluminum deposition film ₂₄ can be measured, for example, by observing a cut surface obtained by cutting the laminated film 1 in the thickness direction with a microscope or the like.

<Adhesive layer>
The adhesive layer 30 is a cured product of an adhesive containing a polyester polyol having a carbon-carbon double bond and a compound having an isocyanate group (hereinafter also simply referred to as "adhesive").
The adhesive is based on a polyester polyol having a carbon-carbon double bond, and a curing agent is a compound having an isocyanate group. That is, the adhesive of this embodiment is a urethane-based adhesive containing a main agent and a curing agent.
As the adhesive, a two-liquid type adhesive consisting of a main agent and a curing agent is preferable from the viewpoint of high curing speed and excellent adhesive strength.

The adhesive layer 30 of the present embodiment has carbon-carbon double bonds in the adhesive component, and thus has oxygen absorbability. Therefore, the laminated film 1 can further enhance the oxygen barrier property. In addition, since the adhesive layer 30 of the present embodiment has oxygen absorbability, even if the base material 10 is damaged by a tear line, the adhesive layer 30 absorbs oxygen and the oxygen permeates the laminated film 1. can be suppressed. Therefore, deterioration of the oxygen barrier property of the laminated film 1 can be suppressed.
The main agent of the adhesive of this embodiment is a polyester polyol having a carbon-carbon double bond in its component, that is, an unsaturated polyester.
Examples of unsaturated polyesters include polyester polyols composed of polyvalent carboxylic acid components containing at least one aromatic dicarboxylic acid or anhydride thereof.
Phthalic anhydride is preferred as the aromatic dicarboxylic acid or its anhydride.
Examples of curing agents for the 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.
As the curing agent, IPDI is preferable from the viewpoints of low environmental load and excellent adhesive strength.

The main agent of the adhesive of this embodiment may contain an N-hydroxyimide compound, a conjugated diene compound, or a transition metal compound.
Examples of N-hydroxyimide compounds include N-hydroxysuccinimide and the like.
Examples of conjugated diene compounds 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, or poly (α-pinene) obtained by cyclizing these compounds, poly (β-pinene), polyterpenes such as poly(dipentene), and the like.
Examples of transition metal compounds include transition metal elements such as iron, nickel, copper, manganese, cobalt, rhodium, titanium, chromium, vanadium and ruthenium, or salts thereof. As the transition metal compound, iron salts, nickel salts, copper salts, manganese salts and cobalt salts are preferred, manganese salts and cobalt salts are more preferred, and cobalt salts are even more preferred.
Salts of transition metal elements are preferably organic acids such as acetic acid, stearic acid, dimethyldithiocarbamic acid, palmitic acid, 2-ethylhexanoic acid, neodecanoic acid, linoleic acid, toric acid, oleic acid, resinic acid, and caprin. acid, naphthenic acid, and the like.
As the transition metal compound, cobalt neodecanoate and cobalt oleate are preferable.

The mass ratio of the main agent and curing agent in the adhesive of the present embodiment is preferably 100:103 to 100:150, more preferably 100:103 to 100:130, even more preferably 100:105 to 100:125. When the mass ratio of the main agent and the curing agent is at least the above lower limit, the adhesive strength can be further increased. When the mass ratio of the main agent and the curing agent is equal to or less than the above upper limit, the vapor barrier property of the laminated film 1 can be further enhanced.

The content of unreacted isocyanate groups in the adhesive layer 30 is 3 to 30 mol%, preferably 3 to 20 mol%, more preferably 5 to 10 mol%, relative to the content of the generated urethane groups. preferable. When the content of unreacted isocyanate groups is at least the above lower limit, the unreacted isocyanate groups absorb water vapor, so that the vapor barrier properties of the laminated film 1 can be further enhanced. When the content of unreacted isocyanate groups is equal to or less than the above upper limit, the adhesive strength can be further increased, which is advantageous in terms of cost.
The content of unreacted isocyanate groups can be measured with a Fourier transform infrared spectrophotometer (FTIR).
Specifically, the laminated film 1 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 infrared wavelength range of 2,500 to 25,000 nm (2.5 to 25 μm), and the peak height of the urethane group and the isocyanate group in the adhesive layer 30 are determined. The content of unreacted isocyanate groups relative to the content of urethane groups can be determined by determining the ratio of the peak height.

The thickness T ₃₀ of the adhesive layer 30 is 1.5-5.0 μm, preferably 2.0-4.0 μm. When the thickness T30 of the adhesive layer ₃₀ is equal to or greater than the above lower limit, the adhesiveness between the substrate 10 and the aluminum deposited film 24 can be further enhanced. In addition, when the thickness T30 of the adhesive layer ₃₀ is equal to or greater than the above lower limit, the vapor barrier properties and oxygen barrier properties of the laminated film 1 can be further enhanced. When the thickness T30 of the adhesive layer ₃₀ is equal to or less than the above upper limit value, the easy-opening property of the laminated film 1 can be further enhanced.
The thickness T30 of the adhesive layer ₃₀ can be measured, for example, by observing a cut surface obtained by cutting the laminated film 1 in the thickness direction with a microscope or the like.

The glass transition temperature of the adhesive layer 30 is preferably −10° C. or higher, more preferably −5° C. or higher. When the glass transition temperature of the adhesive layer 30 is equal to or higher than the above lower limit, it is easy to suppress the generation of whiskers when the laminated film 1 is cleaved. That is, the appearance of the laminated film 1 after being cleaved can be improved. The upper limit of the glass transition temperature of the adhesive layer 30 is not particularly limited, and is substantially 200°C.
The reason why it is easy to suppress the generation of whiskers when the laminated film 1 is cleaved is presumed as follows. If the glass transition temperature of the adhesive layer 30 is equal to or higher than the above lower limit, the adhesive layer 30 tends to be brittle and hard. Therefore, the base material 10 and the aluminum vapor deposition film 24 are prevented from extending more than necessary while adhering to the adhesive layer 30 . As a result, the substrate 10 of the laminated film 1 and the aluminum deposition film 24 are smoothly torn, and the generation of tear marks can be suppressed.
The glass transition temperature of the adhesive layer 30 can be measured by differential thermal analysis (DTA).

≪Method for producing laminated film≫
The method for producing the laminated film 1 includes a step of laminating the substrate 10 and the aluminum deposited film 24 of the sealant material 20 via an adhesive to obtain a laminate (laminate production step), and subjecting the laminate to a heat treatment. and a step of subjecting the other surface B of the base material 10 of the laminate to cutting with a cutting tool (tear line forming step).

<Laminate manufacturing process>
In the laminate manufacturing process, a laminate of the base material 10 and the sealant material 20 is manufactured. Examples of the method for manufacturing the laminate include conventionally known manufacturing methods, for example, a laminate comprising a step of obtaining the base material 10 (base material manufacturing process) and a process of laminating the sealant material 20 (lamination process). A manufacturing method of

A method for obtaining the substrate 10 in the substrate manufacturing 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, configuration, etc. of the substrate 10 .

A method for laminating the base material 10 and the sealant material 20 in the lamination step is selected from conventionally known methods such as a dry lamination method, for example.
In the dry lamination method, for example, an adhesive is applied to the aluminum deposition film 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 pressed and dried. A laminate is thus obtained. The obtained laminate is wound into a roll, for example.

<Heat treatment process>
After manufacturing the laminate as described above, the laminate is subjected to heat treatment in the heat treatment step. Curing of the adhesive is accelerated by heat-treating the laminate.

The temperature of the heat treatment is preferably 30-60°C, more preferably 35-50°C.
When the temperature of the heat treatment is at least the above lower limit, the curing of the adhesive is sufficiently accelerated, the interlayer adhesion is improved, and the ease of opening is easily improved. In addition, it is easy to suppress the generation of whiskers when the laminated film 1 is cleaved. When the temperature of the heat treatment is equal to or lower than the above upper limit, it is easy to suppress thermal damage to each layer constituting the laminate, and it is easy to suppress deterioration of the steam barrier properties and oxygen barrier properties of the laminated film 1 .

The heat treatment time is 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 at least the above lower limit, the curing of the adhesive is sufficiently accelerated, the interlayer adhesion is improved, and the ease of opening is further enhanced. In addition, it is easy to suppress the generation of whiskers when the laminated film 1 is cleaved. When the heat treatment time is equal to or less than the above upper limit, the productivity of the laminated film 1 can be easily improved.
The heat treatment of the laminate can be performed in a conventionally known constant temperature room or the like.
Note that the heat-treated laminate and the unheated laminate can be distinguished by, for example, analyzing the curing state of the adhesives of both by FTIR or nuclear magnetic resonance (NMR).

<Tear line forming process>
Next, the other surface B of the heat-treated laminate substrate 10 is processed with a knife. In the cutting process, for example, the laminated body is passed between a cutting roll and a metal roll that rotate facing each other with the other surface B of the substrate 10 facing the cutting roll. By making the height of the blade of the blade roll smaller than the thickness of the laminate, a tear line can be applied to the laminate through the substrate 10 without penetrating through the laminate.
The maximum depth of the tear line can be adjusted by adjusting the height of the blades of the blade roll.
By the tear line forming step, the laminate film 1 having the tear line formed on the surface of the substrate 10 is obtained.
In addition, when orientation is imparted to the film itself as the substrate 10, the tear line forming step may be omitted.

≪Package≫
The package of this embodiment is produced by bagging the laminated film 1 of this embodiment. As the package, for example, there is a bag manufactured by cutting the laminated film 1 so as to have a square shape in plan view, and heat-sealing the sealant layers 22 of the laminated film 1 to each other.
The size of the package can be, for example, 100 to 1,000 mm long and 10 to 500 mm wide.
Examples of the form of the package include a folded bag, a three-sided sealed bag, a four-sided sealed bag, a gusset bag, a stand bag, and these bags with zippers.

As described above, according to the laminated film 1 of the present embodiment, the vapor barrier property and the oxygen barrier property are excellent due to the vapor-deposited aluminum film 24 . In addition, according to the laminated film 1 of the present embodiment, the content of unreacted isocyanate groups in the adhesive layer 30 is 3 to 30 mol% with respect to the content of the generated urethane groups, It can absorb water vapor. Therefore, the laminated film 1 is excellent in water vapor barrier properties and oxygen barrier properties, and is suitable as a packaging film for foods, medicines, and the like.
Since the base material 10 of the laminated film 1 has linear cuttability, the laminated film 1 can be linearly cleaved without using a knife or the like, and the appearance after cleavage is excellent and the easy-openability is excellent.

[Second embodiment]
A laminated film according to a second embodiment of the present invention will be described with reference to the drawings. The description will focus on the points that are different from the laminated film 1 of FIG.
The laminated film 2 of FIG. 2 is obtained by laminating the substrate 16, the adhesive layer 32, and the sealant material 20 in this order. That is, the laminated film 2 includes a base material 16 and a sealant material 20 positioned on one side A of the base material 16 and has an adhesive layer 32 between the base material 16 and the sealant material 20 .
The base material 16 includes a first resin film 12, a second resin film 14, and a laminate layer .
This embodiment differs from the first embodiment in that the substrate 16 has a multi-layer structure.

Examples of the first resin film 12 include resin films similar to the base material 10, such as PET, OPP, CPP, HDPE, and MDPE.
As the second resin film 14, a resin film similar to the first resin film 12 can be used.
As the laminate layer 34, the same adhesive as the adhesive layer 30 can be used.
By using a multi-layer film as the base material 16, the base material can be a base material that suppresses the permeation of water vapor in addition to the permeation of oxygen.

The thickness T12 of the first resin film ₁₂ is determined in consideration of the material, construction, and the like. The thickness T12 of the first resin film ₁₂ is, for example, preferably 15-130 μm, more preferably 25-65 μm. When the thickness T12 of the first resin film ₁₂ is equal to or greater than the above lower limit, the vapor barrier properties and oxygen barrier properties of the laminated film 2 can be further enhanced. Therefore, the contents are less likely to deteriorate and more difficult to deteriorate. When the thickness T12 of the first resin film ₁₂ is equal to or less than the above upper limit, the easy-opening property of the laminated film 2 can be further enhanced.
The thickness T12 of the first resin film ₁₂ can be measured, for example, with a thickness gauge.

The thickness T ₁₄ of the second resin film 14 is similar to the thickness T ₁₂ of the first resin film 12 .

The thickness T ₃₄ of laminate layer 34 is similar to the thickness T ₃₀ of adhesive layer 30 .
The glass transition temperature of laminate layer 34 is similar to the glass transition temperature of adhesive layer 30 .

A tear line is formed on the other surface B of the second resin film 14 .
The tear line preferably penetrates at least the second resin film 14 and may reach the adhesive layer 32 .
The maximum depth of the tear line is the same as the maximum depth of the tear line formed on the other surface B of the substrate 10 in the first embodiment.

The adhesive layer 32 is the same as the adhesive layer 30 in the first embodiment.
The thickness T ₃₂ of adhesive layer 32 is similar to the thickness T ₃₀ of adhesive layer 30 .
The glass transition temperature of adhesive layer 32 is similar to the glass transition temperature of adhesive layer 30 .

As a method for manufacturing the laminated film 2, the same manufacturing method as for the laminated film 1 can be adopted. For example, a laminate is obtained by obtaining the base material 16 as a base material, laminating the base material 16 and the sealant material 20 via an adhesive, pressing each layer, and drying the layers.
The conditions for heat-treating the laminate are the same as the conditions for heat-treating the laminate in the first embodiment.
Next, the other surface B of the second resin film 14 of the heat-treated laminate is processed with a knife. In the cutting process, for example, the laminate is passed between a cutting roll and a metal roll that rotate in opposition to each other, with the second resin film 14 on the side of the cutting roll. By making the height of the blade of the blade roll smaller than the thickness of the laminate, the tear line can be applied to the laminate through the second resin film 14 without penetrating through the laminate.
The maximum depth of the tear line can be adjusted by adjusting the height of the blades of the blade roll.
Through the tear line forming step, the laminate film 2 having the tear line formed on the surface of the substrate 16 is obtained.
In addition, when orientation is imparted to the film itself as the substrate 16, the tear line forming step may be omitted.

≪Package≫
The package of the present embodiment is obtained by bag-making the laminated film 2 . Examples of the package include a bag formed by cutting the laminated film 2 into a square shape in plan view and heat-sealing the sealant layers 22 of the laminated film 2 to each other.
The size of the package can be, for example, 100 to 1,000 mm long and 10 to 500 mm wide.
Examples of the form of the package include a folded bag, a three-sided sealed bag, a four-sided sealed bag, a gusset bag, and a stand bag.

According to the present embodiment, the water vapor barrier properties and oxygen barrier properties of the substrate can be further enhanced, so that the laminated film can be further improved in water vapor barrier properties and oxygen barrier properties.

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to the following examples.
The materials used in this example are as follows.

[Materials used]
≪Base material≫
· PET: Lumirror (registered trademark), manufactured by Toray Advanced Film Co., Ltd., thickness 12 μm.
Easy-open PET: Eastar (registered trademark), Eastman Chemical Co., Ltd., thickness 12 µm, orientation degree α in MD direction = 3.0, orientation degree in TD direction β = 3.0.
· Easy-to-open OPP: MCMD (registered trademark)-AS, manufactured by Futamura Chemical Co., Ltd., thickness 20 μm, degree of orientation in MD direction α=3.0, degree of orientation in TD direction β=1.5.

≪Sealant material≫
· AL deposition CPP: VM-CPP, manufactured by Toray Advanced Film Co., Ltd., thickness 25 μm.
· AL deposition CPP: Sunmirror (registered trademark), manufactured by Reiko Co., Ltd., thickness 50 μm.
• Silica deposition CPP: MOS (registered trademark), manufactured by Oike Industry Co., Ltd., thickness 30 μm.
· CPP: Pyrene (registered trademark) film-CT, manufactured by Toyobo Co., Ltd., thickness 25 μm.

≪Adhesive layer≫
<Main agent>
・Saturated polyester: manufactured by Nippon Synthetic Chemical Co., Ltd.
・Phthalic anhydride: manufactured by Junsei Chemical Co., Ltd.
・Conjugated diene compound: manufactured by Nippon Synthetic Chemical Co., Ltd.
- Transition metal compound: Organometallic reagent, manufactured by Tokyo Chemical Industry Co., Ltd.
· N-hydroxyimide compound: N-hydroxysuccinimide, manufactured by Tokyo Chemical Industry Co., Ltd.
<Curing agent>
IPDI: Isophorone diisocyanate, Takenate (registered trademark), manufactured by Mitsui Chemicals, Inc.
· HDI: hexamethylene diisocyanate, Takenate (registered trademark), manufactured by Mitsui Chemicals, Inc.

[Examples 1 to 9, Comparative Examples 1 to 7]
Laminates according to the structures of Examples 1 to 9 and Comparative Examples 1 to 7 were produced by laminating the base material, adhesive layer, and sealant material shown in Table 1 and dry laminating them. The thickness of the aluminum deposition film was 50 nm. The easy-open property of the base material in each example was imparted by imparting orientation to the film itself or by cutting the laminate. The height of the blade in the blade processing was 30 μm. The laminate film of each example was obtained by cutting the laminate of each example, if necessary.
In Example 3, the substrate has a multi-layer structure, and PET, which does not impart easy-openability, is the outermost layer. HDI in Example 3 is the curing agent in the laminate layer of the substrate.
The sealant material of Comparative Example 1 is CPP on which aluminum is not vapor-deposited. The sealant material of Comparative Example 7 is CPP in which silica is deposited instead of aluminum.

The obtained laminated film of each example was measured for elongation in the MD or TD direction, tensile elastic modulus in the MD or TD direction, and glass transition temperature of the adhesive layer.
Elongation and tensile modulus were measured according to the test method described in JIS K7127:1999.
The glass transition temperature was measured by DTA.
The content of unreacted isocyanate groups is measured by FTIR (IRAffinity, manufactured by Shimadzu Corporation, irradiation wavelength 1,282 to 28,570 nm) for 1 g of the laminated film, and the peak height of the urethane groups in the adhesive layer and the isocyanate It was calculated from the ratio to the base peak height.
Table 2 shows the results.

[Evaluation method]
<Evaluation of water vapor barrier property>
The laminated film obtained in each example was measured for water vapor transmission rate by the humidity sensor method of JIS K7129:2008, and the water vapor barrier property was evaluated based on the following evaluation criteria. Table 2 shows the results.
"Evaluation criteria"
A: Water vapor permeability of 0.5 g/(m ² ·day) or less.
Good: Water vapor transmission rate more than 0.5 g/(m ² ·day) and 2.0 g/(m ² ·day) or less.
x: More than 2.0 g/(m ² ·day) of water vapor permeability.

<Evaluation of oxygen barrier property>
Regarding the laminated film obtained in each example, the oxygen permeability was measured by the electric field sensor method of JIS K7126-2:2006, and the oxygen barrier property was evaluated based on the following evaluation criteria. Table 2 shows the results.
"Evaluation criteria"
A: Oxygen permeability of 0.5 cm ³ /(m ² ·day·atm) or less.
◯: Oxygen permeability greater than 0.5 cm ³ /(m ² ·day·atm) and less than or equal to 2.0 cm ³ /(m ² ·day·atm).
x: Oxygen permeability greater than 2.0 cm ³ /(m ² ·day · atm).

The sealant layer of the laminated film 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 form a square of 130 mm × 170 mm. A sealed bag (flat bag) was produced. Using this flat bag as a sample for evaluation, the ease of opening and appearance after tearing were evaluated as follows. Table 2 shows the results.

<Evaluation of easy-openability>
The evaluation sample was torn with Strograph E3-L (manufactured by Toyo Seiki Co., Ltd.) to measure the opening force.
At this time, the difference (difference in height from the bottom surface) between the position of the incision at the start of tearing and the position of the incision when the tearing propagation reached 100 mm was measured to evaluate straight cutability. It can be evaluated that the smaller this difference is, the better the straight cutting property.
From the measurement result of the opening force and the evaluation result of the straight cutting property, the easy opening property was evaluated based on the following evaluation criteria.
"Evaluation criteria"
A: Opening force less than 5 N and straight cutability 10 mm or less.
◯: Opening force of 5 N or more and less than 10 N, and straight cutability of 10 mm or less.
x: Unsealing force of 10 N or more, or straight cutting property of more than 10 mm.

<Evaluation of Appearance after Cleavage>
The open end face (the cut end after opening) of the evaluation sample for which easy-openability was evaluated was visually observed, and the appearance after cleavage was evaluated based on the following evaluation criteria.
"Evaluation criteria"
(double-circle): Generation|occurrence|production of a mustache is not recognized.
◯: The occurrence of whiskers is slightly observed, but not conspicuous.
x: Whiskers are conspicuous.

<Comprehensive evaluation>
Based on the evaluation results of the above evaluation of water vapor barrier properties, evaluation of oxygen barrier properties, evaluation of easy openability, and evaluation of appearance after tearing, the laminated film (or package) of each example was comprehensively evaluated according to the following evaluation criteria. Those with a comprehensive evaluation of "⊚" or "◯" were regarded as acceptable.
"Evaluation criteria"
⊚: All the evaluation results of the evaluation of water vapor barrier properties, the evaluation of oxygen barrier properties, the evaluation of easy-to-open properties, and the evaluation of appearance after cleavage are "⊚."
◯: There is no "x" in any of the evaluation results of water vapor barrier property evaluation, oxygen barrier property evaluation, easy opening property evaluation, and appearance evaluation after cleavage.
x: There is "x" in any of the evaluation results of water vapor barrier property evaluation, oxygen barrier property evaluation, easy opening property evaluation, and appearance evaluation after cleavage.

As shown in Tables 1 and 2, Examples 1 to 9, to which the present invention was applied, were rated as "⊚" or "○" in overall evaluation, and had excellent water vapor barrier properties, oxygen barrier properties, easy opening properties, and appearance after cleavage. I was able to confirm that it is excellent.
On the other hand, in Comparative Example 1, which does not have an aluminum deposition film, the evaluation of the water vapor barrier property and the evaluation of the oxygen barrier property were "x".
Comparative Example 2, in which the main component of the adhesive layer has no carbon-carbon double bond, was rated "x" in the evaluation of water vapor barrier property, oxygen barrier property, easy opening property, and appearance after cleavage.
Comparative Example 3, in which the content of unreacted isocyanate groups was small, was evaluated as "poor" in the water vapor barrier property.
Comparative Example 4, in which the thickness of the adhesive layer is thin, was evaluated as "poor" in the evaluation of the water vapor barrier property and the evaluation of the oxygen barrier property.
In Comparative Example 5, in which the elongation of the sealant material was large, the evaluation of the easy-openability and the evaluation of the appearance after cleavage were "x".
Comparative Example 6, in which the tensile elastic modulus of the sealant material is small, was evaluated as "Poor" in the easy-openability evaluation and the evaluation of the appearance after cleavage.
Comparative Example 7, which used a sealant material in which silica was vapor-deposited instead of aluminum, was evaluated as "poor" in the easy-openability evaluation and the evaluation of the appearance after cleavage.

From the above results, it was confirmed that by applying the present invention, a laminated film having excellent water vapor barrier properties and oxygen barrier properties can be obtained, the package can be opened more easily, and the opening end face of the package can be cleaned. .

1, 2 Laminated film 10 Base material 20 Sealant material 22 Sealant layer 24 Aluminum deposited film 30 Adhesive layer

Claims (5)

A base material having straight cutability and a sealant material located on one side of the base material,
The sealant material has an aluminum deposition film,
Having an adhesive layer between the base material and the aluminum deposition film,
The adhesive layer is a cured product of an adhesive containing a polyester polyol having a carbon-carbon double bond and a compound having an isocyanate group,
The content of unreacted isocyanate groups in the adhesive layer is 3 to 30 mol% with respect to the content of generated urethane groups,
The adhesive layer has a thickness of 1.5 to 5.0 μm,
The elongation in the MD direction of the sealant material is 450 to 1000%, the elongation in the TD direction of the sealant material is 500 to 1100%,
The laminated film, wherein the sealant material has a tensile modulus of elasticity in the MD direction of 700 to 1200 MPa, and a tensile modulus of elasticity in the TD direction of the sealant material is 700 to 1200 MPa. 2. The laminated film according to claim 1, wherein a tear line is formed on the other surface of said substrate. 3. The laminated film according to claim 1, wherein the adhesive layer has a glass transition temperature of −10° C. or higher. A package made of the laminated film according to any one of claims 1 to 3. A method for producing a laminated film according to any one of claims 1 to 3,
A method for producing a laminated film, comprising laminating the base material and the aluminum deposition film via the adhesive.

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