JP2020121453A - Laminated film, package, and method for producing laminated film - Google Patents

Abstract

To provide a laminated film which is excellent in an appearance after cleavage, a water vapor barrier property, and an oxygen barrier property, and is more excellent in an easy opening property; a package; and a method for producing the laminated film.SOLUTION: The laminated film 1 includes: a base material 10 having a linear cut property; and a sealant material 20 which is positioned on one surface A of the base material 10. The sealant material 20 has a vapor deposition film 24 of aluminum. The laminated film 1 includes an adhesive layer 30 which is provided between the base material 10 and the vapor deposition film 24 of aluminum. The adhesive layer 30 is a cured product of an adhesive which contains a polyester polyol having a carbon-carbon double bond, and a compound having an isocyanate group. In the adhesive layer 30, a content of unreacted isocyanate groups is 3 to 30 mol% with respect to a content of the generated urethane groups, and the thickness of the adhesive layer 3 is 1.5 to 5.0 μm. In the sealant material 20, degrees of elongation in an MD direction and a TD direction are each in a specific range, and tensile elastic moduli in the MD direction and the TD direction are each in a specific range.SELECTED DRAWING: Figure 1

Description

The present invention relates to a laminated film, a package, and a method for manufacturing the laminated film.

In recent years, there have been increasing opportunities to store foods and medicines in plastic packaging. Since foods and drugs may be altered by water and oxygen, in order to extend the shelf life of the foods and drugs that are the contents, high moisture vapor barrier property and oxygen barrier property are required for the package containing them. ..
Further, in recent years, the number of consumers demanding more convenience is increasing, and a packaging body that can be easily opened by hand without using scissors or a knife at the time of opening the packaging body and can be torn straightly. The demand for (a package having an easy-open property) is increasing.

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

JP, 2017-24377, A

However, when a means for imparting orientation to the film itself is applied like the film for a packaging body of Patent Document 1, it is difficult to cleave the film in a straight line, and the easy opening property is not sufficient.
When a means for physically forming a tear line is applied, the easy-opening property is sufficiently exhibited, but the surface of the film is scratched, so that the water vapor barrier property and the oxygen barrier property may be deteriorated. In addition, a tear mark of the film called "beard" may be generated at the portion where the package is torn, and the appearance of the film may be impaired.

The present invention has been made in view of the above circumstances, and has an appearance after cleavage, excellent water vapor barrier property and oxygen barrier property, and a laminated film excellent in easy opening property, a packaging body, and a method for producing a laminated film. And

As a result of intensive studies, the present inventors have found that a laminated film having the following constitution can solve the above problems.
That is, the film for a package of the present invention has the following constitution.
[1] A base material having a linear cut property and a sealant material located on one surface of the base material, the sealant material having an aluminum vapor deposition film, and the base material and the aluminum vapor deposition film. An adhesive layer is provided between the adhesive layer and the adhesive layer, which 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 which is unreacted in the adhesive layer. The content of the isocyanate group is 3 to 30 mol% with respect to the content of the generated urethane group, the thickness of the adhesive layer is 1.5 to 5.0 μm, and the sealant material The MD direction elongation is 450 to 1000%, the TD direction elongation of the sealant material is 500 to 1100%, the MD elastic modulus of the sealant material is 700 to 1200 MPa, and the sealant material is The laminated film having a tensile elastic modulus 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 in which the laminated film according to any one of [1] to [3] is formed into a bag.

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

According to the laminated film of the present invention, the appearance after cleavage, the water vapor barrier property and the oxygen barrier property are excellent, and the easy opening property is excellent.

It is sectional drawing of the laminated film which concerns on 1st embodiment of this invention. It is sectional drawing of the laminated film which concerns on 2nd embodiment of this invention.

The laminated film of the present invention includes a base material and a sealant material located on one surface of the base material.
Furthermore, the sealant material of the laminated film of the present invention has an aluminum vapor deposition film. The laminated film of the present invention has an adhesive layer between the base material and the aluminum vapor deposition 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 the first embodiment of the present invention will be described with reference to the drawings.
The laminated film 1 of 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 laminated film 1 includes the base material 10, the sealant material 20 located on one surface A of the base material 10, and the adhesive layer 30 located between the base material 10 and the sealant material 20. The sealant material 20 has a sealant layer 22 and an aluminum vapor deposition film 24. The adhesive layer 30 is located between the base material 10 and the aluminum vapor 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). The following is more preferable. When the water vapor permeability of the laminated film 1 is equal to or less than the above upper limit, it is possible to sufficiently suppress the intrusion of moisture from the outside of the package, the contents are less likely to be deteriorated, and the contents are less likely to be deteriorated. That is, the water vapor barrier property of the laminated film 1 can be further enhanced.
The water vapor permeability in the present invention is a value determined by the humidity sensor method of JIS K7129:2008.
The water vapor permeability of the laminated film 1 can be adjusted by the material and thickness of the base material 10, the thickness of the aluminum vapor deposition film 24, the material and thickness of the sealant layer 22, and a combination 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, oxygen invasion from the outside of the package can be sufficiently suppressed, the contents can be more unlikely to be altered, and the contents can be less likely to be deteriorated. 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 obtained 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 base material 10, the thickness of the aluminum vapor deposition film 24, the material and thickness of the sealant layer 22, and a combination thereof.

The thickness _{T 1} of the laminate film 1 is not particularly limited, for example, preferably 35～250Myuemu, more preferably from 40 to 200 [mu] m, more preferably 50 to 150 [mu] m. When the thickness T ₁ of the laminated film 1 is at least the above lower limit value, the water vapor barrier property and the oxygen barrier property of the laminated film 1 can be further enhanced. When the thickness T ₁ of the laminated film 1 is not more than the above upper limit value, the easy-open property of the laminated film 1 can be further enhanced.
The thickness T ₁ of the laminate film 1, for example, can be measured by thickness gauge or the like.

<Substrate>
The base material 10 has a linear cutting property. Examples of the base material 10 include a resin film having a linear cut property. In the present specification, “having a linear cut property” means that, when the base material 10 is torn, the difference between the position of the cut at the beginning of tearing and the position of the cut when the tear propagation reaches 100 mm (perpendicular to the tearing direction). Direction distance) is 10 mm or less.
As the resin film, polyethylene terephthalate (PET), biaxially oriented PET, polyester film such as polybutylene terephthalate (PBT), polypropylene (PP), biaxially oriented polypropylene (OPP), non-oriented polypropylene (CPP), high density Examples thereof 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 preferable, and biaxially stretched PET and OPP are more preferable.
Examples of the laminate include a laminate of the above resin films.
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 producing a film) of more than 1.0 and 3.5 or less, preferably 1.1 to 3.2, more preferably 1.2 to 3. 0 is more preferable. When the degree of orientation α is not less than the above lower limit, the easy-open property can be further enhanced. When the orientation degree α is equal to or less than the above upper limit, it is easy to suppress the occurrence of beard when the package is cleaved. That is, the appearance of the package after cleavage can be improved.
The substrate 10 has an orientation degree β in the TD direction (direction perpendicular to the MD direction) of more than 1.0 and preferably 3.5 or less, more preferably 1.1 to 3.2, and 1.2 to 3.0. More preferable. When the degree of orientation β is at least the above lower limit, the easy-open property 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 occurrence of beard when the package is cleaved. That is, the appearance of the package after cleavage can be improved.
The ratio represented by the orientation degree α/orientation degree β of the base material 10 (hereinafter sometimes referred to as α/β ratio) is preferably 0.5 to 2.0, and more preferably 0.5 to 1.5. .. When the α/β ratio is within the above numerical range, the easy-open property can be further improved. In particular, when the laminated film 1 is made into a bag to form a package, the linear cuttability can be further improved. That is, it becomes easy 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 base material 10. This effect becomes particularly strong when a biaxially stretched resin film is used as the base material 10.

The orientation degree α and the orientation degree β are calculated from the values measured by the infrared dichroic 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, in an infrared spectrophotometer.
As a measuring method, first, a background (BKG) measurement is performed with a polarizer installation angle of 0° (the electric field is oriented in the vertical direction), and then the stretching direction of the sample is aligned with the longitudinal direction to measure the absorbance ( At this time, the polarization direction and the stretching axis direction are parallel to each other.). The obtained value is defined as the absorbance “A//”.
Next, the angle of the sample is rotated by 90°, and the absorbance is measured in a state where the stretching axis of the sample is perpendicular to the polarization direction. Let the obtained value be the absorbance “A⊥”.
The degree of orientation is defined as the absorbance ratio ([A//]/[A⊥]) of the two absorbances A// and A⊥ obtained with polarized light parallel to the stretching axis of the sample and polarized light perpendicular to the stretching axis.

A tear line may be formed on the other surface B of the base material 10. The tear line is a linear or perforated cut and is formed by subjecting the other surface B of the base material 10 to a cutting tool process or the like. Since the tear line is formed, the laminated film 1 can be easily torn without using a knife such as scissors. In addition, since the tear line is formed, the linear cuttability of the base material 10 can be further enhanced. The linear cut is a continuous groove in which a slight thickness is left on the base material 10. The perforation-like cut is a slit or groove formed continuously in the base material 10 at a predetermined interval.

The tear line is formed to enhance the easy-open property of the laminated film 1. From the viewpoint of improving the easy-opening property of the laminated film 1, the tear line is preferably formed to a depth of at least about half the thickness T ₁₀ of the base material 10, and penetrates the base material 10 to form the adhesive layer 30. More preferably, or penetrates the adhesive layer 30.
Maximum depth of the tear line is preferably, for example, 20-80% of the thickness _{T 1} of the laminate film 1, and more preferably from 30% to 70%, more preferably 40 to 60%. When the maximum depth of the tear line is at least the above lower limit value, the easy-open property of the laminated film 1 can be further enhanced. When the maximum depth of the tear line is not more than the above upper limit value, the water vapor barrier property and the oxygen barrier property 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 substrate 10 is determined in consideration of the material and configuration and the like, for example, preferably 5 to 100 [mu] m, 10 to 50 [mu] m is more preferable. If the thickness T ₁₀ of the substrate 10 is not less than the above lower limit, is increased more water vapor barrier properties and oxygen barrier properties of the laminated film 1. If the thickness T ₁₀ of the substrate 10 is not more than the above upper limit, it is increased more the easily openable of the laminated film 1.
The thickness of the base material 10 can be measured with a thickness gauge, for example.

<Sealant material>
The sealant material 20 is located on one surface A of the base material 10. The sealant material 20 has a sealant layer 22 and an aluminum vapor deposition film 24. The aluminum vapor deposition film 24 is located on one surface C of the sealant layer 22. The adhesive layer 30 is located between the base material 10 and the aluminum vapor deposition film 24, and the sealant material 20 is laminated on the one surface A of the base material 10 via the adhesive layer 30.

The MD direction elongation of the sealant material 20 is 450 to 1000%, preferably 450 to 800%, and more preferably 500 to 650%. When the MD direction elongation of the sealant material 20 is equal to or more than the above lower limit value, the strength of the laminated film 1 can be further increased. When the elongation of the sealant material 20 in the MD direction is equal to or less than the above upper limit value, it is easy to suppress the occurrence of beard when the laminated film 1 is cleaved. That is, the appearance after cleavage of the laminated film 1 can be improved.
The MD direction 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 a value obtained by dividing the increase amount (mm) of the distance between marked lines in the MD direction of the test piece by the distance between marked lines of the test piece (mm) and multiplying by 100 (%). ).
The MD elongation of the sealant material 20 can be adjusted by the thickness of the aluminum vapor 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 at least the above lower limit value, 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 value, it is easy to suppress the occurrence of beard when the laminated film 1 is cleaved. That is, the appearance of the laminated film 1 after cleavage can be improved.
The elongation in the TD direction of the sealant material 20 can be measured in the same manner as the elongation in the MD direction of the sealant material 20. The elongation in the TD direction of the sealant material 20 is a value obtained by dividing the increase amount (mm) of the distance between marked lines in the TD direction of the test piece by the distance between marked lines of the test piece (mm) and multiplying by 100 (%). ) Is given.
The elongation in the TD direction of the sealant material 20 can be adjusted by the thickness of the aluminum vapor deposition film 24, the material and thickness of the sealant layer 22, and a combination thereof.

The tensile modulus in the MD direction of the sealant material 20 is 700 to 1200 MPa, preferably 800 to 1100 MPa, more preferably 900 to 1000 MPa. When the tensile elastic modulus in the MD direction of the sealant material 20 is at least the above lower limit value, the linear cuttability of the laminated film 1 can be further enhanced. When the tensile elastic modulus in the MD direction of the sealant material 20 is equal to or less than the above upper limit value, it is easy to suppress the occurrence of beard when the laminated film 1 is cleaved. That is, the appearance after cleavage of the laminated film 1 can be improved.
The tensile modulus 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 in the MD direction of the sealant material 20 can be adjusted by the thickness of the aluminum vapor 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 elastic modulus of the sealant material 20 in the TD direction can be measured by the same method as the tensile elastic modulus of the sealant material 20 in the MD direction.
The tensile elastic modulus in the TD direction of the sealant material 20 can be adjusted by the thickness of the aluminum vapor 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 and configuration and the like, for example, preferably from 5 to 150 m, more preferably from 5 to 100 [mu] m, more preferably 10 to 50 [mu] m. If the thickness T ₂₀ of the sealant material 20 is not less than the above lower limit, is increased more water vapor barrier properties and oxygen barrier properties of the laminated film 1. If the thickness T ₂₀ of the sealant material 20 is not more than the above upper limit, it is increased more the easily openable of the laminated film 1.
The thickness _{T 20} of the sealant material 20 can be measured, for example, in thickness gauge.

(Sealant layer)
The sealant layer 22 enhances the sealing property of the laminated film 1.
Examples of the resin forming the sealant layer 22 include low-density polyethylene (LDPE), linear LDPE (LLDPE), MDPE, HDPE, polyolefins such as CPP, ethylene-vinyl alcohol polymer (EVOH), and ethylene-vinyl acetate copolymer. Examples thereof include a polymer (EVA), an ethylene-acrylic acid copolymer (EAA), an ethylene-methacrylic acid copolymer (EMAA), an ethylene-ethyl acrylate copolymer (EEA), and an ionomer. 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 alone or in combination of two or more.

The thickness _{T 22} of the sealant layer 22 is determined in consideration of the material and the like, for example, preferably from 5 to 100 [mu] m, more preferably 5～90Myuemu, more preferably 10 to 50 [mu] m. If the thickness T ₂₂ of the sealant layer 22 is not less than the above lower limit, is increased more the sealability of the laminated film 1. If the thickness T ₂₂ of the sealant layer 22 is not more than the upper limit, it is increased more the easily openable of the laminated film 1.
The thickness _{T 22} of the sealant layer 22, for example, can be measured by thickness gauge.

(Aluminum vapor deposition film)
The aluminum vapor deposition film 24 has a water vapor barrier property and an oxygen barrier property. That is, the aluminum vapor deposition film 24 in this embodiment has a role of suppressing permeation of water vapor and oxygen.
In the present embodiment, the aluminum vapor deposition film 24 is formed on the sealant layer 22 instead of the base material 10. Therefore, even if a tear line is formed on the base material 10 and the adhesive layer 30, the vapor-deposited aluminum film 24 can maintain the water vapor barrier property and the oxygen barrier property of the laminated film 1.
In addition, by laminating the sealant material 20 having the aluminum vapor deposition film 24 and the base material 10 having an easy opening property, the laminated film 1 having an excellent steam barrier property and an oxygen barrier property and an easy opening property is easily formed. In addition, it can be obtained at low cost.

For example, the thickness T ₂₄ of the aluminum vapor deposition film 24 is preferably 30 to 70 nm, more preferably 30 to 50 nm. If the thickness T ₂₄ of the aluminum deposited layer 24 is not less than the above lower limit, it is possible to suppress the deterioration of water vapor barrier properties and oxygen barrier properties. 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. If the thickness T ₂₄ of the aluminum deposited layer 24 is not more than the above upper limit, it is increased more the easily openable of the laminated film 1.
The thickness T ₂₄ of the aluminum vapor 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 (hereinafter, also simply referred to as “adhesive”) containing a polyester polyol having a carbon-carbon double bond and a compound having an isocyanate group.
The adhesive is mainly composed of a polyester polyol having a carbon-carbon double bond, and a compound having an isocyanate group is a curing agent. That is, the adhesive of the present embodiment is a urethane-based adhesive containing a main agent and a curing agent.
As the adhesive, a two-liquid type adhesive containing a main agent and a curing agent is preferable from the viewpoints of rapid curing speed and excellent adhesive strength.

The adhesive layer 30 of the present embodiment has a carbon-carbon double bond in the components of the adhesive, and thus has an oxygen absorbing property. Therefore, the laminated film 1 can further improve the oxygen barrier property. In addition, since the adhesive layer 30 of the present embodiment has an oxygen absorbing property, even if the base material 10 is damaged by a tear line, the adhesive layer 30 absorbs oxygen and oxygen permeates the laminated film 1. Can be suppressed. Therefore, it is possible to suppress deterioration of the oxygen barrier property of the laminated film 1.
The main component 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 a polyvalent carboxylic acid component containing at least one aromatic dicarboxylic acid or anhydride thereof.
As the aromatic dicarboxylic acid or its anhydride, phthalic anhydride is preferable.
Examples of the curing agent 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 base material of the adhesive of the present embodiment may contain an N-hydroxyimide compound, a conjugated diene compound, and a transition metal compound.
Examples of the N-hydroxyimide compound include N-hydroxysuccinimide and the like.
Examples of the conjugated diene compound 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 Examples include polyterpenes such as (β-pinene) and poly(dipentene).
Examples of the transition metal compound include transition metal elements such as iron, nickel, copper, manganese, cobalt, rhodium, titanium, chromium, vanadium and ruthenium, and salts thereof. The transition metal compound is preferably iron salt, nickel salt, copper salt, manganese salt and cobalt salt, more preferably manganese salt and cobalt salt, and further preferably cobalt salt.
As the salt of the transition metal element, an organic acid is preferable, and examples thereof include acetic acid, stearic acid, dimethyldithiocarbamic acid, palmitic acid, 2-ethylhexanoic acid, neodecanoic acid, linoleic acid, tallic acid, oleic acid, resin acid and capric acid. Acid, naphthenic acid, etc. are mentioned.
The transition metal compound is preferably cobalt neodecanoate or cobalt oleate.

The mass ratio of the main agent and the curing agent in the adhesive of the present embodiment is preferably 100:103 to 100:150, more preferably 100:103 to 100:130, and even more preferably 100:105 to 100:125. When the mass ratio of the main agent to the curing agent is at least the above lower limit value, the adhesive strength can be further increased. When the mass ratio of the main agent and the curing agent is not more than the above upper limit value, the water vapor barrier property of the laminated film 1 can be further enhanced.

The content of the unreacted isocyanate group in the adhesive layer 30 is 3 to 30 mol %, preferably 3 to 20 mol %, more preferably 5 to 10 mol% with respect to the content of the generated urethane group. preferable. When the content of the unreacted isocyanate group is not less than the above lower limit value, the unreacted isocyanate group absorbs water vapor, so that the water vapor barrier property of the laminated film 1 can be further enhanced. When the content of the unreacted isocyanate group is less than or equal to the above upper limit, the adhesive strength can be further increased, which is also advantageous in terms of cost.
The content of unreacted isocyanate groups can be measured by a Fourier transform infrared spectrophotometer (FTIR).
Specifically, 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 wavelength range of infrared light of 2,500 to 25,000 nm (2.5 to 25 μm) to find the peak height of the urethane group and the isocyanate group of the adhesive layer 30. By determining the ratio with the height of the peak, the content of unreacted isocyanate groups with respect to the content of urethane groups can be determined.

The thickness T ₃₀ of the adhesive layer 30 is 1.5 to 5.0 μm, preferably 2.0 to 4.0 μm. If the thickness T ₃₀ of the adhesive layer 30 is not less than the above lower limit is more enhanced the adhesion between the substrate 10 and the aluminum deposited layer 24. In addition, the thickness T ₃₀ of the adhesive layer 30 is the not less than the above lower limit, is increased more water vapor barrier properties and oxygen barrier properties of the laminated film 1. If the thickness T ₃₀ of the adhesive layer 30 is not more than the upper limit, it is increased more the easily openable of the laminated film 1.
The thickness T ₃₀ 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 occurrence of whiskers when the laminated film 1 is cleaved. That is, the appearance after cleavage of the laminated film 1 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 occurrence of whiskers when the laminated film 1 is cleaved is presumed as follows. When the glass transition temperature of the adhesive layer 30 is at least the above lower limit value, the adhesive layer 30 tends to be brittle and hard. Therefore, it is possible to prevent the base material 10 and the aluminum vapor deposition film 24 from extending more than necessary while being attached to the adhesive layer 30. As a result, the base material 10 of the laminated film 1 and the aluminum vapor deposition film 24 are smoothly torn, and the occurrence of tear marks can be suppressed.
The glass transition temperature of the adhesive layer 30 can be measured by a differential thermal analysis method (DTA).

<<Method for manufacturing laminated film>>
The manufacturing method of the laminated film 1 includes a step of obtaining a laminated body by laminating the base material 10 and the aluminum vapor deposition film 24 of the sealant material 20 with an adhesive (a laminated body manufacturing step), and a heat treatment to the laminated body. The method includes a step of performing (heat treatment step) and a step of subjecting the other surface B of the base material 10 of the above-mentioned laminated body to a cutting tool (breaking line forming step).

<Laminate manufacturing process>
In the laminated body manufacturing process, a laminated body of the base material 10 and the sealant material 20 is manufactured. As a method for manufacturing the laminate, a conventionally known manufacturing method can be mentioned, and for example, a laminate including a step of obtaining the base material 10 (base material manufacturing step) and a step of laminating the sealant material 20 (lamination step) The manufacturing method of is mentioned.

The method of obtaining the base material 10 in the base material manufacturing step is selected from conventionally known methods such as an inflation method, a T-die method, a co-extrusion method, etc., depending on the material and configuration of the base material 10.

The method of laminating the base material 10 and the sealant material 20 in the laminating step is selected from conventionally known methods such as a dry laminating method.
In the dry laminating method, for example, an adhesive is applied to the aluminum vapor deposition film 24 of the sealant material 20 to be laminated, the base material 10 and the sealant material 20 are laminated with the adhesive, and each layer is pressure-bonded and dried. Thereby, a laminated body is obtained. The obtained laminated body is wound into a roll, for example.

<Heat treatment step>
After the laminated body is manufactured as described above, in the heat treatment step, the laminated body is subjected to heat treatment. The heat treatment of the laminate accelerates the curing of the adhesive.

30-60 degreeC is preferable and, as for the temperature of heat processing, 35-50 degreeC is more preferable.
When the temperature of the heat treatment is at least the above lower limit, the curing of the adhesive is sufficiently promoted, the interlayer adhesiveness becomes good, and the easy-open property is easily enhanced. In addition, it is easy to suppress the occurrence 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 value, it is easy to prevent each layer constituting the laminate from being damaged by heat, and it is easy to suppress deterioration of the water vapor barrier property and the oxygen barrier property of the laminated film 1.

The heat treatment time is preferably 5 hours or longer, more preferably 5 to 96 hours, still more preferably 12 to 48 hours. When the time of the heat treatment is not less than the above lower limit value, the curing of the adhesive is sufficiently promoted, the interlayer adhesiveness becomes good, and the easy-open property is further enhanced. In addition, it is easy to suppress the occurrence of beard when the laminated film 1 is cleaved. When the heat treatment time is not more than the above upper limit, the productivity of the laminated film 1 is likely to be improved.
The heat treatment of the laminate can be performed in a conventionally known constant temperature chamber or the like.
The laminated body subjected to the heat treatment and the laminated body not subjected to the heat treatment can be discriminated by, for example, analyzing the cured state of both adhesives by FTIR or nuclear magnetic resonance (NMR).

<Rupture line forming step>
Next, the other surface B of the base material 10 of the heat-treated laminated body is subjected to cutting tool processing. In the blade processing, for example, the layered body is passed between the blade roll and the metal roll that face each other with the other surface B of the substrate 10 as the blade roll side. By making the height of the blade of the blade roll smaller than the thickness of the laminated body, a tear line penetrating the base material 10 can be applied to the laminated body without penetrating the laminated body.
The maximum depth of the tear line can be adjusted by the height of the blade of the blade roll.
By the tear line forming step, the laminated film 1 in which the tear lines are formed on the surface of the base material 10 is obtained.
When the film itself as the base material 10 is provided with orientation, the tear line forming step may be omitted.

<<Package>>
The package of the present embodiment is obtained by bag-making the laminated film 1 of the present embodiment. As the package, for example, a bag formed by cutting the laminated film 1 so as to have a rectangular shape in a plan view and heat-sealing the sealant layers 22 of the laminated film 1 to each other can be cited.
The size of the package may be, for example, 100 to 1,000 mm in length and 10 to 500 mm in width.
The form of the package includes, for example, a joint-sealed bag, a three-sided sealed bag, a four-sided sealed bag, a gusset bag, a stand bag, a zipper bag of these, and the like.

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

[Second embodiment]
A laminated film according to the second embodiment of the present invention will be described with reference to the drawings. Description will be focused on points different from the laminated film 1 of FIG. 1, and the same members will be denoted by the same reference numerals and description thereof will be omitted.
The laminated film 2 of FIG. 2 is obtained by laminating the base material 16, the adhesive layer 32, and the sealant material 20 in this order. That is, the laminated film 2 includes the base material 16 and the sealant material 20 located on one surface A of the base material 16, and has the 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 34.
The present embodiment differs from the first embodiment in that the base material 16 has a multilayer structure.

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

The thickness T ₁₂ of the first resin film 12 is determined in consideration of the material, the configuration and the like. The thickness T ₁₂ of the first resin film 12 is preferably, for example, 15 to 130 μm, more preferably 25 to 65 μm. When the thickness T _{12 of} the first resin film 12 is at least the above lower limit value, the water vapor barrier property and the oxygen barrier property of the laminated film 2 can be further enhanced. Therefore, the contents are less likely to be altered and the contents are less likely to be deteriorated. When the thickness T _{12 of} the first resin film 12 is not more than the above upper limit value, the easy-open property of the laminated film 2 can be further enhanced.
The thickness T ₁₂ of the first resin film 12 can be measured with a thickness gauge, for example.

The thickness _{T 14} of the second resin film 14 is the same as the thickness _{T 12} of the first resin film 12.

The thickness _{T 34} of the laminate layer 34 are the same as the thickness _{T 30} of the adhesive layer 30.
The glass transition temperature of the laminate layer 34 is similar to the glass transition temperature of the 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 rupture line is the same as the maximum depth of the rupture line formed on the other surface B of the base material 10 in the first embodiment.

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

As a method of manufacturing the laminated film 2, the same manufacturing method as that of the laminated film 1 can be adopted. For example, a laminated body 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 under pressure, and drying.
The conditions for applying heat treatment to the laminate are the same as the conditions for applying heat treatment to the laminate in the first embodiment.
Then, the other surface B of the second resin film 14 of the heat-treated laminated body is subjected to blade processing. In the blade processing, for example, the second resin film 14 is passed between the blade roll and the metal roll, which face each other and face each other, with the second resin film 14 being the blade roll side. By making the height of the blade of the blade roll smaller than the thickness of the laminated body, a tear line penetrating the second resin film 14 can be applied to the laminated body without penetrating the laminated body.
The maximum depth of the tear line can be adjusted by the height of the blade of the blade roll.
By the tear line forming step, the laminated film 2 having the tear lines formed on the surface of the base material 16 is obtained.
When the film itself is provided with orientation as the base material 16, the tear line forming step may be omitted.

<<Package>>
The package of the present embodiment is a bag in which the laminated film 2 is manufactured. Examples of the package include a bag formed by cutting the laminated film 2 and heat-sealing the sealant layers 22 of the laminated film 2 so as to form a quadrangle in a plan view.
The size of the package may be, for example, 100 to 1,000 mm in length and 10 to 500 mm in width.
The form of the package includes, for example, a joint-sealed bag, a three-sided sealed bag, a four-sided sealed bag, a gusset bag, and a stand bag.

According to this embodiment, since the water vapor barrier property and the oxygen barrier property of the base material can be further enhanced, the water vapor barrier property and the oxygen barrier property of the laminated film can be further improved.

Hereinafter, the present invention will be described 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]
<<Substrate>>
-PET: Lumirror (registered trademark), manufactured by Toray Film Processing Co., Ltd., thickness 12 μm.
Easy-open PET: Eastar (registered trademark), Eastman Chemical Co., thickness 12 μm, orientation degree α in MD direction α=3.0, orientation degree β in TD direction=3.0.
Easy opening OPP: MCMD (registered trademark)-AS, manufactured by Futamura Chemical Co., Ltd., thickness 20 μm, degree of orientation α in MD direction α=3.0, degree of orientation β in TD direction β=1.5.

≪Sealant material≫
-AL vapor deposition CPP: VM-CPP, Toray Film Co., Ltd. thickness, 25 micrometers.
-AL vapor deposition CPP: Sunmirror (registered trademark), manufactured by Reiko Co., Ltd., thickness 50 μm.
Silica vapor deposition CPP: MOS (registered trademark), manufactured by Oike Kogyo 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 type 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 and Comparative Examples 1 to 7]
By laminating the base material, the adhesive layer, and the sealant material shown in Table 1, and performing dry lamination, a laminate according to the configurations of Examples 1 to 9 and Comparative Examples 1 to 7 was manufactured. The thickness of the aluminum vapor deposition film was 50 nm. The easy-opening property of the base material of each example was imparted by making the film itself oriented or by subjecting the laminate to cutting tool processing. The height of the blade in processing the blade was 30 μm. The laminated body of each example was obtained by subjecting the laminated body of each example to a cutting tool if necessary.
In addition, in Example 3, the base material has a multi-layer structure, and PET which does not impart easy opening property is the outermost layer. HDI in Example 3 is a curing agent in the laminate layer of the substrate.
The sealant material of Comparative Example 1 is CPP on which aluminum is not deposited. The sealant material of Comparative Example 7 is CPP in which silica is deposited instead of aluminum.

With respect to the obtained laminated film of each example, the elongation in the MD direction or the TD direction, the tensile elastic modulus in the MD direction or the TD direction, and the glass transition temperature of the adhesive layer were measured.
The elongation and the tensile elastic 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 was measured by FTIR (IRAffinity, manufactured by Shimadzu Corporation, irradiation wavelength 1,282-28,570 nm) for 1 g of the laminated film, and the peak height of the urethane group and the isocyanate in the adhesive layer were measured. It was calculated from the ratio with the height of the base peak.
The results are shown in Table 2.

[Evaluation method]
<Evaluation of water vapor barrier properties>
The water vapor permeability of the laminated film obtained in each example was measured by 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 Table 2.
"Evaluation criteria"
⊚: Water vapor permeability is 0.5 g/(m ² ·day) or less.
◯: Water vapor permeability of more than 0.5 g/(m ² ·day) and 2.0 g/(m ² ·day) or less.
X: Water vapor permeability exceeding 2.0 g/(m ² ·day).

<Evaluation of oxygen barrier property>
The oxygen permeability of the laminated film obtained in each example 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. The results are shown in Table 2.
"Evaluation criteria"
⊚: Oxygen permeability of 0.5 cm ³ /(m ² ·day·atm) or less.
◯: Oxygen permeability of more than 0.5 cm ³ /(m ² ·day·atm) and 2.0 cm ³ /(m ² ·day·atm) or less.
X: Oxygen permeability of more 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 obtain a 130 mm×170 mm square A seal bag (flat bag) was produced. Using this flat bag as a sample for evaluation, the ease of opening and the appearance after cleavage were evaluated as follows. The results are shown in Table 2.

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

<Evaluation of appearance after cleavage>
The open end surface (cut end after opening) of the evaluation sample for which easy-opening property was evaluated was visually observed, and the appearance after cleavage was evaluated based on the following evaluation criteria.
"Evaluation criteria"
⊚: No beard was observed.
◯: Whiskers were slightly observed but not noticeable.
X: The occurrence of whiskers is noticeable.

<Comprehensive evaluation>
Based on the evaluation results of the evaluation of the water vapor barrier property, the evaluation of the oxygen barrier property, the evaluation of the easy-open property, and the evaluation of the appearance after cleavage, the laminated film (or the package) of each example was comprehensively evaluated according to the following evaluation criteria. Those with a comprehensive evaluation of "◎" or "○" were judged to be acceptable.
"Evaluation criteria"
⊚: All the evaluation results of evaluation of water vapor barrier property, evaluation of oxygen barrier property, evaluation of easy-open property, and evaluation of appearance after cleavage are “⊚”.
◯: “X” does not exist in all evaluation results of evaluation of water vapor barrier property, evaluation of oxygen barrier property, evaluation of easy-open property, and evaluation of appearance after cleavage.
X: "x" is present in any of the evaluation results of the evaluation of water vapor barrier property, the evaluation of oxygen barrier property, the evaluation of easy opening property, and the evaluation of appearance after cleavage.

As shown in Tables 1 and 2, in Examples 1 to 9 to which the present invention was applied, the comprehensive evaluation was “⊚” or “∘”, and the water vapor barrier property, the oxygen barrier property, the easy-open property, and the appearance after cleavage were evaluated. It was confirmed to be excellent.
On the other hand, in Comparative Example 1 not provided with the aluminum vapor deposition film, the evaluation of the water vapor barrier property and the evaluation of the oxygen barrier property were “x”.
In Comparative Example 2 in which the main component of the adhesive layer had no carbon-carbon double bond, the evaluation of the water vapor barrier property, the evaluation of the oxygen barrier property, the evaluation of the easy-open property, and the evaluation of the appearance after cleavage were “X”.
In Comparative Example 3 in which the content of unreacted isocyanate groups was small, the water vapor barrier property was evaluated as “x”.
In Comparative Example 4 in which the thickness of the adhesive layer was thin, the water vapor barrier property evaluation and the oxygen barrier property evaluation were “x”.
In Comparative Example 5 in which the sealant material had a large elongation, the evaluation of the easy-open property and the evaluation of the appearance after cleavage were “X”.
In Comparative Example 6 in which the tensile elastic modulus of the sealant material was small, the evaluation of the easy-open property and the evaluation of the appearance after cleavage were “X”.
In Comparative Example 7 in which a sealant material obtained by depositing silica instead of aluminum was used, the evaluation of the easy-open property and the evaluation of the appearance after cleavage were “X”.

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

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

Claims (5)

A base material having a linear cut property, and a sealant material located on one surface of the base material,
The sealant material has an aluminum vapor deposition film,
An adhesive layer is provided between the base material and the aluminum vapor 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 the unreacted isocyanate group in the adhesive layer is 3 to 30 mol% with respect to the content of the generated urethane group,
The thickness of the adhesive layer is 1.5 to 5.0 μm,
The MD direction elongation of the sealant material is 450 to 1000%, the TD direction elongation of the sealant material is 500 to 1100%,
A laminated film in which the tensile elastic modulus in the MD direction of the sealant material is 700 to 1200 MPa, and the tensile elastic modulus in the TD direction of the sealant material is 700 to 1200 MPa. The laminated film according to claim 1, wherein a tear line is formed on the other surface of the base material. The laminated film according to claim 1 or 2, wherein the glass transition temperature of the adhesive layer is -10°C or higher. A package in which the laminated film according to any one of claims 1 to 3 is formed into a bag. It is a manufacturing method of the laminated film as described in any one of Claims 1-3,
A method for producing a laminated film, comprising laminating the base material and the aluminum vapor deposition film via the adhesive.

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