JP6659309B2 - Film for packaging and package - Google Patents

Description

  The present invention relates to a package film and a package.

2. Description of the Related Art In recent years, opportunities to accommodate foods and drugs in plastic packaging have been increasing. Since foods and medicines may be degraded by oxygen gas, in order to extend the shelf life of foods and medicines, which are contained, a package containing these is required to have high oxygen gas barrier properties.
The package containing the food and the medicine is transported or stored until it is used. If the seal part is peeled off due to impact during transportation or storage and the sealing property of the package is impaired, or if the package is cracked by dropping, etc., oxygen gas will enter the package and alter the contents. Or the contents are leaked. For this reason, the package is required to have excellent sealing properties and impact resistance that does not easily cause cracks or the like upon impact such as dropping.
Patent Document 1 discloses a laminated packaging material in which a saponified ethylene-vinyl acetate copolymer is used as an intermediate layer, a surface layer is provided on both sides of the intermediate layer, and the respective layers are arranged via an adhesive resin layer. Further, a laminated packaging material in which the main component of the surface layer is a blend of linear low-density polyethylene and high-pressure low-density polyethylene is disclosed. According to Patent Document 1, the laminated packaging material is said to be excellent in gas barrier properties and tearability.
Patent Document 2 discloses a multilayer active oxygen barrier film including a passive oxygen barrier layer and an active oxygen barrier layer. According to Patent Document 2, the film can maintain a high oxygen barrier property.

JP-A-5-345390 JP 2010-537849 A

By the way, in recent years, consumers who demand more convenience are increasing, and from the viewpoint of barrier-free, a package which can be easily opened by hand without using scissors or a knife when opening the package. Demand is growing. Further, when the package is torn in an unintended direction at the time of opening, there is a problem that the contents are scattered around. For this reason, the package is required to have easy-openability that can be easily opened by hand and can be opened in the intended direction.
However, the techniques of Patent Documents 1 and 2 have not been able to sufficiently satisfy all of the oxygen gas barrier properties, sealing properties, impact resistance, and easy-openability. Further, the laminated packaging material described in Patent Document 1 and the multilayer active oxygen barrier film described in Patent Document 2 have five or more layers, and are not excellent in productivity and economy.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a packaging film having excellent oxygen gas barrier properties, sealing properties, impact resistance, and excellent openability.

As a result of intensive studies, the present inventors have found that the following film for a package can solve the above-mentioned problems.
That is, the packaging film of the present invention has the following configuration.
[1] A package film including a sealant material including a laminate layer, a seal layer, and an intermediate layer disposed between the laminate layer and the seal layer, wherein the laminate layer and the seal layer include: A layer of a mixture of an acid-modified polyolefin and a polyolefin, and containing 10 to 70% by mass of the acid-modified polyolefin, wherein the intermediate layer is selected from an ethylene-vinyl alcohol polymer, polyvinyl alcohol, and a xylylenediamine-based polyamide resin A layer containing at least one of the above, wherein the thickness of the sealant material is more than 20 μm and less than 130 μm.
[2] The film for a package according to claim 1, wherein at least one of the laminate layer and the seal layer contains a lubricant and an antiblocking agent.
[3] The film for a package according to [1] or [2], wherein the intermediate layer contains an oxygen absorbent.
[4] The package film according to any one of claims 1 to 3, further comprising a substrate provided on the laminate layer.
[5] A package in which the package film of [1] to [4] is formed.

  The film for a package of the present invention is excellent in oxygen gas barrier properties, sealing properties, impact resistance, and excellent in easy-openability.

It is sectional drawing of the film for packages of this invention.

The package film of the present invention includes a sealant material including a laminate layer, a seal layer, and an intermediate layer disposed between the laminate layer and the seal layer.
Hereinafter, the package film of the present invention will be described with reference to embodiments.

  A film for a package according to an embodiment of the present invention will be described with reference to the drawings.

(Packaging film)
The film 1 for a package shown in FIG. 1 is a film in which a base material 10 and a sealant material 30 are laminated.
The sealant material 30 includes a laminate layer 22, a seal layer 24, and an intermediate layer 26 disposed between the laminate layer 22 and the seal layer 24.
The base material 10 is provided on the laminate layer 22.
The thickness T1 of the film for a package ₁ is not particularly limited, but is preferably, for example, 35 to 250 μm, more preferably 40 to 200 μm, and still more preferably 50 to 150 μm. When it is not less than the above lower limit, the strength of the film for packaging 1 is easily increased, and when it is not more than the above upper limit, the flexibility of the film for packaging 1 is enhanced and the handling property is improved.

Oxygen permeability of the wrapping material film 1 is preferably ^{4.0cc / (m 2 · day ·} atm) or ^{less, 3.0cc / (m 2 · day} · atm) , more preferably less, 1.0 cc / (m ² · day · atm) or less, more preferably 0.5 cc / (m ² · day · atm) or less. When the oxygen permeability of the film 1 for a package is equal to or less than the upper limit, deterioration and deterioration of the contents can be easily suppressed.
The oxygen permeability in the present invention is a value determined by the Mocon method of JIS K7126-1.

Water vapor permeability of the wrapping material film 1, for example, preferably 3g ^/ (m 2 · day) or ^{less, 1g / (m 2 · day} ) or less is more preferable. When the water vapor permeability of the film for a package 1 is equal to or less than the upper limit, intrusion of moisture from the outside of the package can be sufficiently suppressed, and deterioration and deterioration of the contents can be easily suppressed.
The water vapor transmission rate in the present invention is a value determined by the Mocon method of JIS K7129 (2008).

<Base material 10>
Examples of the substrate 10 include a resin film, metal foil, paper, and a laminate thereof.
Examples of the resin film include polyolefins such as polyethylene terephthalate (PET) such as biaxially oriented polyethylene terephthalate, biaxially oriented polypropylene (OPP), unoriented polypropylene (CPP), high-density polyethylene (HDPE), and medium-density polyethylene (MDPE). , Polyamide (PA) such as biaxially stretched nylon (ONY), and a laminate thereof. Among them, PET, OPP, and nylon (NY) are preferred.
Further, as the base material 10, a vapor-deposited film in which a metal such as aluminum or silica or the like is vapor-deposited on the resin film may be used. Among them, a metal-deposited film in which a metal is deposited on PET, OPP, and ONY is preferable, and an aluminum-deposited film is more preferable.
Aluminum foil is preferred as the metal foil.
Examples of the laminate include a laminate of the above resin films and a laminate of the above resin film and metal foil.
The substrate 10 may be printed on the surface or between layers.

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. When it is not less than the lower limit, the strength of the film for packaging 1 is easily increased, and when it is not more than the above upper limit, the flexibility of the film for packaging 1 is enhanced and handling is easy.

The substrate 10 has a degree of orientation α in the MD direction (the flow direction in producing a film) of preferably 0.5 to 3.5, more preferably 0.7 to 3.2, and 1.0 to 3.0. Is more preferred. When the degree of orientation α is equal to or more than the lower limit, the easy-open property is easily enhanced. When the orientation degree α is equal to or less than the upper limit, the sealing property and the impact resistance are easily improved. Further, the blocking resistance is easily increased.
The substrate 10 has a degree of orientation β in the TD direction (a direction perpendicular to the MD direction) of preferably 0.2 to 3.5, more preferably 0.5 to 3.2, and more preferably 0.7 to 3.0. preferable. When the content is equal to or more than the lower limit, the easy opening property is easily improved. When the content is equal to or less than the upper limit, the sealing property and the impact resistance are easily improved. Further, the blocking resistance is easily increased.
The ratio represented by the degree of orientation α / degree of orientation 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-mentioned preferred range, the easy-opening property is easily enhanced. In particular, when the film 1 for a package is formed into a package by bag-making, the straight-line cutting property is easily enhanced. That is, the package can be easily opened in the intended direction.
In addition, the easy opening property of the film 1 for a package is affected by the α / β ratio of the base material 10. In particular, when a biaxially stretched resin film is used as the base material 10, this effect becomes strong.

The orientation degree α and the orientation degree β are calculated from values measured by the infrared two-color method.
The degree of orientation is measured by a transmission method using light called linearly polarized light whose electric field vibrates only in a certain direction in an infrared spectrophotometer.
As a measuring method, first, a BKG (background) measurement is performed by setting the installation angle of the polarizer to 0 ° (the direction of the electric field is vertical), and then the stretching direction of the sample is adjusted to the vertical direction, and the absorbance is measured ( At this time, the polarization direction and the direction of the stretching axis are parallel.) The obtained value is defined as absorbance “A //”.
Next, the angle of the sample is rotated by 90 °, and the absorbance is measured in a state in which the stretching axis of the sample is perpendicular to the polarization direction. The obtained value is defined as absorbance “A⊥”.
The degree of orientation is defined as the ratio of the two absorbances A // and A ［([A //] / [A⊥]) obtained with polarized light parallel and perpendicular to the stretching axis of the sample.
The measurement wave number in the infrared two-color method is appropriately selected according to the material to be measured (“Jinji Kobayashi,“ Molecular Orientation by Infrared Two-Color Method ”), Journal of the Society of Polymer Science,“ Polymer ”, Vol. No. 175, pp. 877-883 ”).
Further, the degree of orientation can be easily obtained from the tensile modulus measured according to JIS K7127 (1999).

<Sealant material 30>
The sealant material 30 includes a laminate layer 22, a seal layer 24, and an intermediate layer 26. The intermediate layer 26 is disposed between the laminate layer 22 and the seal layer 24. In the present embodiment, the sealant material 30 includes three layers: a laminate layer 22, a seal layer 24, and an intermediate layer 26.
The thickness _{T 30} of the sealant material 30 is less than 20μm ultra 130 .mu.m. When T ₃₀ is a 20μm greater, sealability, impact resistance is enhanced. When T ₃₀ is less than 130 .mu.m, easy-open performance can be enhanced. Further, the blocking resistance is improved. T30 is preferably 25 to 125 µm, more preferably ₃₀ to 100 µm, still more preferably 35 to 80 µm, and particularly preferably 40 to 60 µm.

The oxygen permeability of the sealant material 30 is the same as the oxygen permeability of the packaging film 1.
The water vapor transmission rate of the sealant material 30 is the same as the water vapor transmission rate of the packaging film 1.
The degree of orientation α of the sealant material 30 is the same as the degree of orientation α of the film for packaging 1.
The degree of orientation β of the sealant material 30 is the same as the degree of orientation β of the film 1 for a package.
The α / β ratio of the sealant material 30 is the same as the α / β ratio of the film 1 for a package.

<< Lamination layer 22 >>
The laminate layer 22 is a layer of a mixture of an acid-modified polyolefin and a polyolefin. The acid-modified polyolefin has polarity. By forming the laminate layer 22 as a layer of a mixture of an acid-modified polyolefin and a polyolefin, the orientation of the laminate layer 22 is enhanced, and the easy-openability is enhanced. Further, the adhesion between the laminate layer 22 and an intermediate layer 26 described later is enhanced. In addition, the winding property at the time of winding the sealant material 30 into a roll is improved, and the handling property is enhanced.
The laminate layer 22 contains 10 to 70% by mass of the acid-modified polyolefin with respect to the total mass of the laminate layer 22 (that is, the total mass of the acid-modified polyolefin and the polyolefin). When the content of the acid-modified polyolefin is equal to or more than the lower limit, the easy opening property is improved. Further, it becomes easy to adjust the degree of orientation of the sealant material 30 to a desired range. Further, the adhesion between the laminate layer 22 and an intermediate layer 26 described later is enhanced. When the content of the acid-modified polyolefin is equal to or less than the upper limit, the sealing property and the impact resistance are improved. Further, blocking resistance is enhanced.
When the content of the acid-modified polyolefin is less than the lower limit, the adhesive strength between the laminate layer 22 and the base material 10 and the adhesive strength between the laminate layer 22 and the intermediate layer 26 described below cannot be ensured. Propagation at break is deteriorated, and easy-openability is impaired.
The content of the acid-modified polyolefin is preferably from 20 to 70% by mass, more preferably from 30 to 70% by mass, and still more preferably from 40 to 60% by mass, based on the total mass of the laminate layer 22.

The polyolefin is not particularly limited. For example, polyethylene (PE) such as low-density polyethylene (LDPE), linear LDPE (LLDPE), medium-density polyethylene (MDPE), and high-density polyethylene (HDPE); OPP), polypropylene (PP) such as unstretched polypropylene (CPP), an ethylene-propylene copolymer, an ethylene-butene-1 copolymer, and the like.
Any of these may be used alone or two or more of them may be used in combination.

The acid-modified polyolefin is obtained by polymerizing an unsaturated carboxylic acid or a derivative thereof on a polyolefin.
The polyolefin used as the raw material of the acid-modified polyolefin is not particularly limited, and examples thereof include the above-mentioned polyolefins.
Examples of the unsaturated carboxylic acid as a raw material of the acid-modified polyolefin include, for example, acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid or anhydrides thereof, among which maleic acid, anhydride Maleic acid, itaconic acid and itaconic anhydride are preferred, and maleic acid or maleic anhydride is more preferred.
As the acid-modified polyolefin, acid-modified polypropylene and acid-modified polyethylene are preferable.
Examples of the acid-modified polypropylene include maleic acid-modified polypropylene, maleic anhydride-modified polypropylene, itaconic acid-modified polypropylene, and itaconic anhydride-modified polypropylene.
Examples of the acid-modified polyethylene include maleic acid-modified polyethylene, maleic anhydride-modified polyethylene, itaconic acid-modified polyethylene, and itaconic anhydride-modified polyethylene.
These acid-modified polyolefins may be used alone or in combination of two or more.

The laminate layer 22 is preferably made of a mixture of acid-modified polypropylene and polypropylene, a mixture of acid-modified polyethylene and polyethylene, and a mixture of maleic acid-modified polypropylene or maleic anhydride-modified polypropylene and polypropylene, maleic acid-modified polyethylene or anhydrous. More preferably, it is composed of a mixture of maleic acid-modified polyethylene and polyethylene, more preferably, a mixture of maleic acid-modified polyethylene or maleic anhydride-modified polyethylene and polyethylene.
When the laminate layer 22 is formed from the above mixture, the easy-opening property, the sealing property, and the impact resistance are easily improved. In addition, the adhesiveness to the later described intermediate layer 26 is easily increased.

The laminate layer 22 preferably contains a lubricant and / or an anti-blocking agent.
When the laminate layer 22 contains a lubricant and / or an anti-blocking agent, the blocking resistance of the sealant material 30 is improved.

Examples of the lubricant include, but are not particularly limited to, liquid paraffin, microcrystalline wax, natural paraffin, synthetic paraffin, aliphatic hydrocarbon-based lubricants such as polyethylene, stearic acid, lauric acid, hydroxystearic acid, and fatty acids such as hardened castor oil fatty acid. System lubricant, stearic acid amide, oleic acid amide, erucic acid amide, lauric acid amide, palmitic acid amide, behenic acid amide, ricinoleic acid amide, oxystearic acid amide, methylenebisstearic acid amide, ethylene bisstearic acid amide, ethylene bis Fatty acid amide lubricants such as oleic acid amide, ethylenebisbehenic acid amide, ethylenebislauric acid amide, lead stearate, calcium stearate, hydroxystearic acid Metal soap-based lubricants which are metal salts of fatty acids having 12 to 30 carbon atoms such as lucium, glycerin fatty acid esters, hydrogenated castor oil, fatty acid (partial) ester-based lubricants of polyhydric alcohols such as hydroxystearic acid triglyceride, sorbitan fatty acid esters, stearic acid Fatty acid ester-based lubricants such as long-chain ester waxes having 8 to 50 carbon atoms such as butyl ester and montan wax, or composite lubricants obtained by combining these lubricants.
Of these, fatty acid amide-based lubricants are preferred.
The antiblocking agent is not particularly limited, but examples thereof include silica, calcium carbonate, titania, mica, talc, and acrylic resins such as polymethyl methacrylate (PMMA).
Among these, silica and PMMA are preferred.

The content of the lubricant in the laminate layer 22 is not particularly limited, and is appropriately adjusted according to the type of the lubricant, but is preferably 200 ppm or more based on the total mass of the laminate layer 22. When the content of the lubricant is equal to or more than the lower limit, the blocking resistance of the sealant material 30 is more easily increased. The content of the lubricant is preferably 500 ppm or more, more preferably 1000 ppm or more, and may be 2000 ppm or more based on the total mass of the laminate layer 22.
On the other hand, the upper limit of the content of the lubricant is not particularly limited, but from the viewpoint that the effect of blending the lubricant saturates and that the sealing property and impact resistance of the film for packaging 1 may be impaired. , Less than 6000 ppm, more preferably 5,000 ppm or less.
The content of the lubricant is preferably 200 ppm or more and less than 6000 ppm, more preferably 200 to 5000 ppm, further preferably 500 to 5000 ppm, and particularly preferably 1000 to 5000 ppm, based on the total mass of the laminate layer 22.

The content of the anti-blocking agent in the laminate layer 22 is not particularly limited, and is appropriately adjusted according to the type of the anti-blocking agent, but is preferably 200 ppm or more based on the total mass of the laminate layer 22. When the content of the anti-blocking agent is equal to or more than the lower limit, the blocking resistance of the sealant material 30 is easily increased. The content of the antiblocking agent is preferably 500 ppm or more, more preferably 1000 ppm or more, and may be 2000 ppm or more, based on the total mass of the laminate layer 22.
On the other hand, the upper limit of the content of the anti-blocking agent is not particularly limited, but there is a possibility that the effect of adding the anti-blocking agent is saturated, and that the sealing property and impact resistance of the film for a package 1 are impaired. From a certain point or the like, it is preferably less than 10,000 ppm, more preferably 5000 ppm or less.
The content of the antiblocking agent is preferably 200 ppm or more and less than 10000 ppm, more preferably 200 to 5000 ppm, still more preferably 500 to 5000 ppm, and particularly preferably 1000 to 5000 ppm based on the total mass of the laminate layer 22.

The laminate layer 22 preferably contains both a lubricant and an anti-blocking agent. Among them, a fatty acid amide-based lubricant is preferably used as a lubricant, and silica or PMMA is preferably used as an anti-blocking agent.
When the laminate layer 22 contains both a lubricant and an anti-blocking agent, the mass ratio of the lubricant to the anti-blocking agent in the laminate layer 22 is preferably lubricant: anti-blocking agent = 1: 9 to 8: 2, preferably 2 to 8. : 8 to 7: 3 is more preferable. When the mass ratio of the lubricant to the anti-blocking agent is within the above-mentioned preferred range, the anti-blocking property is more easily enhanced.
When the laminate layer 22 contains both a lubricant and an anti-blocking agent, the total content thereof is preferably 400 ppm or more based on the total mass of the laminate layer 22. When the total content of the lubricant and the anti-blocking agent is equal to or more than the lower limit, the blocking resistance of the sealant material 30 is easily increased. The total content of the lubricant and the antiblocking agent is more preferably 1000 ppm or more, more preferably 2000 ppm or more, and may be 4000 ppm or more, based on the total mass of the laminate layer 22.
On the other hand, the upper limit value of the total content of the lubricant and the anti-blocking agent is not particularly limited, but the effect of compounding the lubricant and the anti-blocking agent is saturated, and the sealing property and the impact resistance of the film 1 for a package. Is less than 16000 ppm, and more preferably 10,000 ppm or less, from the viewpoint that is likely to be damaged.
The total content of the lubricant and the antiblocking agent is preferably 400 ppm or more and less than 16000 ppm, more preferably 400 to 10000 ppm, still more preferably 1000 to 5000 ppm, and particularly preferably 2000 to 5000 ppm, based on the total mass of the laminate layer 22.

The thickness _{T 22} of the laminate layer 22, 10 to 50 [mu] m is preferred, 15～35Myuemu is more preferable. When T ₂₂ is at the lower limit or more, sealability, impact resistance tends enhanced. When T ₂₂ is less than the upper limit, the easy-open can easily be increased.
T _22, from the viewpoint of impact resistance can be further increased, it is preferably larger than the thickness T ₂₆ of the intermediate layer 26 will be described later. The difference between T ₂₂ and _{T 26} is preferably at 5μm or more. On the other hand, flexibility is enhanced wrapping material film 1, from the viewpoint of handling properties are further enhanced, the difference between T ₂₂ and T ₂₆ is preferably 20μm or less.

{Seal layer 24}
The seal layer 24 is the same as the laminate layer 22. That is, the seal layer 24 is a layer of a mixture of an acid-modified polyolefin and a polyolefin similarly to the laminate layer 22, and contains 10 to 70% by mass of the acid-modified polyolefin in the layer. As the acid-modified polyolefin and the polyolefin in the seal layer 24, the same ones as the laminate layer 22 are used.
The seal layer 24 preferably contains the same lubricant and / or anti-blocking agent as the laminate layer 22.
The thickness _{T 24} of the sealing layer 24 is the same as the thickness _{T 22} of the laminate layer 22.
The seal layer 24 and the laminate layer 22 may be the same (the same composition and thickness) or may be different. When the seal layer 24 and the laminate layer 22 are the same, it is easy to suppress the distortion and curling of the sealant material 30.

≪Mid layer 26≫
The intermediate layer 26 is disposed between the laminate layer 22 and the seal layer 24.
The intermediate layer 26 is a layer containing at least one selected from ethylene-vinyl alcohol polymer (EVOH), polyvinyl alcohol (PVOH), and xylylenediamine-based polyamide resin.
The sealant material 30 has an oxygen gas barrier property by including the intermediate layer 26.
As the above EVOH, those having a copolymerization ratio of ethylene of 10 to 50 mol% are preferable.
The xylylenediamine-based polyamide resin is a polycondensate of xylylenediamine and a linear aliphatic dicarboxylic acid. Examples of the xylylenediamine include metaxylylenediamine, a mixture of metaxylylenediamine and paraxylylenediamine, and the like. Examples of the linear aliphatic dicarboxylic acid include linear aliphatic dicarboxylic acids having 6 to 12 carbon atoms, and include adipic acid, sebacic acid, suberic acid, dodecane diacid, and mixtures thereof. As the xylylenediamine-based polyamide resin, a polycondensate of metaxylylenediamine and adipic acid is preferable.
As the xylylenediamine-based polyamide resin, a synthetic product may be used, or a commercially available product may be used. Examples of commercially available products include the “MX Nylon” series manufactured by Mitsubishi Gas Chemical Company, Ltd.

The thickness T26 of the intermediate layer ₂₆ is appropriately adjusted in consideration of the material of the intermediate layer 26 and the like, but is preferably, for example, 1 to 50 μm, more preferably 2 to 30 μm, and still more preferably 5 to 15 μm. If T ₂₆ is equal to or greater than the lower limit, oxygen gas barrier properties are easily improved. If T ₂₆ is less than the upper limit, flexibility is enhanced wrapping material film 1, the handling of the wrapping material film 1 is improved.

The mid layer 26 preferably contains an oxygen absorbent. When the film for a package 1 is provided with an intermediate layer 26 containing an oxygen absorbent, when the film for a package 1 is formed into a package, oxygen entering from the outside of the package to the inside is removed. Since the oxygen gas can be captured by the layer 26, the oxygen gas barrier property is further enhanced. Further, when the contents are stored in the package, oxygen entering the head space or the like of the container can be absorbed by the intermediate layer 26. For this reason, the amount of oxygen inside the package can be further reduced, the deterioration of the contents can be further suppressed, and the shelf life of the contents can be further extended.
In particular, when a metal foil such as an aluminum foil or a metal vapor-deposited film on which a metal such as aluminum is vapor-deposited is used as the base material 10, it is preferable to use the sealant 30 having the intermediate layer 26 containing an oxygen absorbent as the sealant material 30. preferable.

Known materials can be used as the oxygen absorbent. Examples of the oxygen absorbent include transition metal salts, compounds having a carbon-carbon double bond, and the like. The transition metal salt also has a function as an oxygen absorption catalyst.
Examples of the transition metal salts include iron salts, nickel salts, copper salts, manganese salts, cobalt salts, rhodium salts, titanium salts, chromium salts, vanadium salts, ruthenium salts and the like. Of these, 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.
As the anion constituting the transition metal salt, an organic acid is preferable, for example, acetic acid, stearic acid, dimethyldithiocarbamic acid, palmitic acid, 2-ethylhexanoic acid, neodecanoic acid, linoleic acid, tallic acid, oleic acid, resin acid , Capric acid and naphthenic acid.
As the transition metal salt, cobalt neodecanoate and cobalt oleate are preferable.

  The compound having a carbon-carbon double bond is not particularly limited, but polyterpenes such as poly (α-pinene), poly (β-pinene), and poly (dipentene), conjugated diene polymers, and cyclized products thereof And cyclized conjugated diene polymers.

Examples of the conjugated diene polymer include a homopolymer or a copolymer of a conjugated diene monomer, and a copolymer of a conjugated diene monomer and another monomer. Examples of the other monomer include a monomer copolymerizable with the conjugated diene monomer.
Examples of the conjugated diene monomer include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 2-phenyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1, Examples thereof include 3-pentadiene, 1,3-hexadiene, 4,5-diethyl-1,3-octadiene, and 3-butyl-1,3-octadiene. One of these monomers may be used alone, or two or more thereof may be used in combination. Among these, 1,3-butadiene and isoprene are preferred, and isoprene is more preferred.
The monomer copolymerizable with the conjugated diene monomer is not particularly limited, for example, aromatic vinyl monomers such as styrene, methyl styrene, dimethyl styrene, ethyl styrene, butyl styrene, chlorostyrene, and bromostyrene Linear olefin monomers such as ethylene, propylene and 1-butene; cyclic olefin monomers such as cyclopentene and 2-norbornene; 1,5-hexadiene, 1,6-heptadiene, 1,7-octadiene and dicyclo. Non-conjugated diene monomers such as pentadiene and 5-ethylidene-2-norbornene; (meth) acrylates such as methyl (meth) acrylate and ethyl (meth) acrylate; (meth) acrylonitrile, (meth) acrylamide and the like Is mentioned. One of these monomers may be used alone, or two or more thereof may be used in combination.
Examples of the conjugated diene polymer include natural rubber (NR), styrene-butadiene rubber (SBR), polyisoprene rubber (IR), polybutadiene rubber (BR), isoprene-isobutylene copolymer rubber (IIR), and ethylene-propylene-diene-based polymer. Copolymer rubber, butadiene-isoprene copolymer rubber (BIR) and the like can be mentioned. Among them, polyisoprene rubber and polybutadiene rubber are preferred, and polyisoprene rubber is more preferred.

The cyclized conjugated diene polymer is obtained by cyclizing the conjugated diene polymer in the presence of an acid catalyst.
Examples of the acid catalyst used in the cyclization reaction include sulfuric acid; fluoromethanesulfonic acid, difluoromethanesulfonic acid, p-toluenesulfonic acid, xylenesulfonic acid, alkylbenzenesulfonic acid having an alkyl group having 2 to 18 carbon atoms, Organic sulfonic acid compounds such as anhydrides or alkyl esters; boron trifluoride, boron trichloride, tin tetrachloride, titanium tetrachloride, aluminum chloride, diethyl aluminum monochloride, ethyl ammonium dichloride, aluminum bromide, antimony pentachloride, Metal halides such as tungsten chloride and iron chloride; and the like. One of these acid catalysts may be used alone, or two or more thereof may be used in combination.
The glass transition temperature (Tg) of the cyclized conjugated diene polymer is not particularly limited, but is preferably in the range of 0 to 100 ° C, more preferably 30 to 70 ° C.

  The content of the oxygen absorbent in the intermediate layer 26 is appropriately adjusted according to the oxygen gas barrier properties of the intermediate layer 26, for example, 0.01 to 15% by mass based on the total mass of the intermediate layer 26. Preferably, 0.1 to 10% by mass is more preferable, and 1 to 8% by mass is further preferable. When the content of the oxygen absorbent in the intermediate layer 26 is equal to or more than the lower limit, the oxygen gas barrier property is further improved. In addition, when the packaging film 1 is formed into a package by making a bag, oxygen existing in the head space can be sufficiently absorbed, and the shelf life of the content can be more easily extended. When the content of the oxygen absorbent in the intermediate layer 26 is equal to or less than the upper limit, the flexibility of the intermediate layer 26 is not easily impaired, and the handleability is enhanced.

An adhesive layer may be provided between the intermediate layer 26 and the laminate layer 22. By providing the adhesive layer, the integration between the intermediate layer 26 and the laminate layer 22 is further enhanced, and the impact resistance is more likely to be enhanced.
As the material constituting the adhesive layer, conventionally known materials can be used, for example, polyurethane-based, polyester-based, epoxy-based, polyvinyl acetate-based, acid-modified polyolefin-based adhesives, titanate-based, polyurethane-based, Anchor coating agents such as polyethyleneimine and polybutadiene are exemplified. These materials may be used alone or in combination of two or more.
When an adhesive layer is provided, its thickness is not particularly limited, but is preferably, for example, 0.01 to 4 μm.

(Production method of film 1 for package)
The film 1 for a package is manufactured according to a conventionally known manufacturing method.
The method for manufacturing the packaging film 1 includes a base material forming step of forming the base material 10, a sealant material forming step of forming the sealant material 30, and a laminating step of stacking the base material 10 and the sealant material 30.

  As a manufacturing method of the film 1 for a package, a base material forming step, a sealant material forming step, and a laminating step are independently performed (method A), a base material forming step, a sealant material forming step, and a laminating method. And a method in which the steps are performed in one step (method B).

Method A is a method in which the base material forming step, the sealant material forming step, and the laminating step are performed independently.
The base material forming step in the method A is a step of obtaining the base material 10. The step of obtaining the substrate 10 is selected from conventionally known methods according to the material and configuration of the substrate 10.
The method for obtaining the substrate 10 is selected from conventionally known methods such as an inflation method, a T-die method, and a co-extrusion method, depending on the material and configuration of the substrate 10.
The sealant material forming step in the method A is a step of obtaining the sealant material 30. A method for obtaining the sealant material 30 is selected from conventionally known methods according to the material and configuration of the sealant material 30.
The method for obtaining the sealant material 30 is selected from conventionally known methods such as a co-extrusion method using a T-die co-extruder, an inflation co-extruder, or the like.
The laminating step in the method A is a step of laminating the base material 10 and the sealant material 30 to form the film 1 for a package.
Examples of a method of laminating the base material 10 and the sealant material 30 include a method of applying an adhesive to one surface of the base material 10 and then pressing the base material 10 and the sealant material 30 by pressure.

Method B is a method in which a base material forming step, a sealant material forming step, and a laminating step are performed in one step.
As the method B, for example, there is a method in which the base material 10 and the sealant material 30 are integrally formed by inflation molding using a circular die.
The molding conditions in the inflation molding are appropriately determined in consideration of the material of the base material 10, the degree of orientation, and the like. For example, blow-up ratio: 1.2 to 2.5, take-off speed: 5 to 50 m / min, temperature of resin forming sealant material 30: 160 to 210 ° C., temperature of resin forming base material 10: 200 to Co-extrude at 250 ° C.

As a method for producing the film for a package 1, method B is preferable, and inflation molding is more preferable. In the case of inflation molding, it is easy to reduce the difference in the degree of stretching (degree of orientation) between the layers. For this reason, it is possible to more favorably prevent the package from being warped or twisted when the bag is made.
The difference in the degree of orientation α between the materials is preferably ± 0 to 0.3. Further, the difference in the degree of orientation β between the materials is preferably ± 0 to 0.3. According to inflation molding, it is easy to adjust the difference in the degree of orientation between the materials within the above range.

(Package)
The package of the present invention uses the package film 1. Examples of the package include a bag made by heat-sealing the seal layers 24 of the film 1 for a package. Examples of the form of the package include a gasket-attached bag, a three-side seal bag, a four-side seal bag, a gusset bag, and a stand bag.

  As described above, the package film 1 of the present invention is excellent in oxygen gas barrier properties, sealing properties, impact resistance, and is excellent in easy-openability. For this reason, the packaging film 1 is suitable as a packaging film for foods, medicines, and the like. In particular, when the intermediate layer 26 contains an oxygen absorbent, the oxygen gas barrier property of the film for a package 1 is further enhanced, and the package manufactured from the film for a package 1 can reduce oxygen existing in a head space or the like. It can be absorbed and the contents can be further prevented from being altered by oxygen. Therefore, the shelf life of the contents can be further extended. The film 1 for a package of the present invention is particularly suitable as a film for a package of foods, medicines, and the like, which are easily deteriorated by oxygen. Conventionally, in order to obtain a package film that requires multiple functions such as oxygen gas barrier properties, sealing properties, impact resistance, and easy opening properties, layers each having the above functions are laminated, for example, a multilayer structure of five or more layers. I needed to. In the present invention, the above function can be provided by one layer of the sealant material 30 by configuring the sealant material 30 according to the present invention. Therefore, when manufacturing the packaging film 1, large-scale manufacturing equipment is not required, and the productivity and the economic efficiency are excellent.

  A package made from the film for a package of the present invention has excellent oxygen gas barrier properties, sealing properties, impact resistance, and excellent openability. For this reason, the package of the present invention is suitable as a package for food and medicine. In particular, when the intermediate layer 26 contains an oxygen absorbent, the oxygen gas barrier property of the package is further improved, and oxygen existing in the head space or the like inside the package can be adsorbed, and the contents are altered by oxygen. For a longer period of time. Therefore, the shelf life of the contents can be further extended. For this reason, the package of the present invention is particularly suitable as a package for foods, medicines, and the like that are easily deteriorated by oxygen. Further, according to the package of the present invention, for example, a process such as nitrogen replacement, which is performed when a content that is easily degraded by oxygen is accommodated in the package, can be omitted, and productivity and economic efficiency are excellent.

(Other embodiments)
In the package film 1 of the above embodiment, the base material 10 and the sealant material 30 are laminated, but the package film of the present invention is not limited to this. The base material 10 may be omitted, and the film 1 for a package may be made of only the sealant material 30.
Since the sealant material 30 of the present invention is excellent in oxygen gas barrier properties, sealing properties, impact resistance, and excellent in easy-openability, it can be used as it is as a film for a package. However, by using a material having excellent oxygen gas barrier properties and impact resistance as the base material 10, the oxygen gas barrier properties and impact resistance of the film for packaging 1 can be further improved. It is preferable to provide the base material 10 from the viewpoint of facilitating the modification.
When the base material 10 is omitted, the easy opening property is easily enhanced by setting the α / β ratio of the sealant material 30 to 0.5 to 2.0, preferably 0.5 to 1.5. In particular, when the film for a package is formed into a package by making a bag, the straight-line cutting property is easily enhanced.

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.

(Material used)
<Substrate>
-PET: Lumirror (trade name), manufactured by Toray Film Processing Co., Ltd.
-Alumina deposited PET: Ecosial VE (trade name), manufactured by Toyobo Co., Ltd.
-Al: aluminum foil, manufactured by UACJ Corporation.
-OPP: Pyrene film-OT (trade name), manufactured by Toyobo Co., Ltd.

<Sealant material>
≪Laminating layer, sealing layer≫
-Acid-modified PE: maleic anhydride-modified polyethylene, Modick (trade name), manufactured by Mitsubishi Chemical Corporation.
-PE: polyethylene.
[Lubricant]
-Erucic acid amide.
[Anti-blocking agent (AB agent)]
Silica _(SiO 2).

≪Middle layer≫
EVOH: ethylene content 35 mol%, EVAL (trade name), manufactured by Kuraray Co., Ltd.
-MX nylon: MXD nylon (trade name), manufactured by Mitsubishi Gas Chemical Company, Ltd.
[Oxygen absorbent]
Oxygen absorbent A: conjugated diene polymer cyclized product.
-Oxygen absorbent B: cobalt neodecanoate.

(Examples 1 to 10, Comparative Examples 1 to 4)
The base material and the sealant material shown in Tables 1 and 2 were laminated to produce a package film according to the configurations of Examples 1 to 8, 10 and Comparative Examples 1 to 4. At this time, lamination was performed so that the MD direction of the base material and the MD direction of the sealant material, and the TD direction of the base material and the TD direction of the sealant material were respectively matched.
In Example 9, the sealant material was used as it was as a package film without using a base material. Examples 4 and 5 are reference examples.

  With respect to the obtained packaging films, the oxygen gas barrier properties, sealing properties, impact resistance, and easy-opening properties were evaluated as follows. Table 3 shows the evaluation results.

[Evaluation of oxygen gas barrier properties]
The oxygen permeability of the packaging film of each example was measured by the Mocon method of JIS K7126-1, and when the oxygen permeability was 0.5 cc / (m ² · day · atm) or less, “◎”, 0.5 cc ^{/ (m 2 · day · atm} ) super ^{4.0cc / (m 2 · day ·} atm) following a "○", was ^{4.0cc / (m 2 · day ·} atm) than as "×".

[Evaluation of sealing performance]
Using the packaging film obtained in each example, a 130 mm × 170 mm flat bag was produced.
At this time, a flat bag was produced such that the MD direction of the film for the package was the longitudinal direction of the flat bag, and the TD direction of the film for the package was the short direction of the flat bag. 180 g of water was put into this flat bag, and the opening was sealed by heat sealing (sealing temperature: 180 ° C., sealing time: 1 second, sealing pressure: 3.5 kg / cm ² , sealing width: 10 mm). Sample. The seal strength of the heat seal portion formed at the opening of the evaluation sample was measured under the following measurement conditions in accordance with JIS Z1707 “Heat Seal Strength Test”. The measurement was performed five times, and the average value was defined as the seal strength. Using this seal strength as an index, sealability was evaluated according to the following evaluation criteria.
≪Measurement method≫
Test piece: 15 mm width.
Measurement environment: 23 ° C., 50% RH.
Measuring instrument: Strograph EL (manufactured by Toyo Seiki Seisaku-sho, Ltd.).
Grip interval: 50 mm.
Tensile speed: 300 mm / min.
評 価 Evaluation criteria for sealing performance≫
A: Seal strength is 40 N / 15 mm or more.
：: Sealing strength is more than 15 N / 15 mm and less than 40 N / 15 mm.
X: Seal strength is 15 N / 15 mm or less.

[Evaluation of impact resistance]
The impact resistance of the evaluation sample in the above [Evaluation of Sealability] was evaluated by a drop test. The drop test was performed in accordance with JIS Z0200-8.5.5.2. The test conditions were as follows.
An evaluation sample arranged vertically from a height of 120 cm is dropped on the concrete surface. This operation is repeated three times. Of the ten evaluation samples, the number of samples in which leakage of contents was observed was counted, and evaluated according to the following evaluation criteria.
：: The number of samples where leakage was observed was 0 (“0/10”).
：: The number of samples where leakage was observed was 2 or less (“2/10” or less).
×: The number of samples where leakage was observed was 3 or more (“3/10” or more).

[Evaluation of openability]
The easy-opening property of the evaluation sample in the above [Evaluation of sealing property] was evaluated according to the following evaluation criteria using the following opening property and linear cut property as indices.
<Evaluation of openability>
The expert panelists evaluated the openability felt when the sample for evaluation was torn by hand and opened, according to the following evaluation criteria.
評 価 Evaluation criteria for openability≫
：: When tearing by hand, tearing can be easily performed, and the tearing force during tearing is easily propagated.
×: When tearing by hand, it cannot be easily torn and / or the tearing force during the tearing is difficult to propagate.

<Evaluation of linear cut property>
When the sample for evaluation is torn under the same conditions as in the above <Evaluation of openability>, the difference between the position of the cut at the beginning of the tear and the position of the cut when the tear propagation reaches 100 mm (the difference in height from the bottom surface) Was measured, and the linear cut property was evaluated based on the following evaluation criteria. It can be evaluated that the smaller the difference is, the more excellent the straight-line cutting property is.
評 価 Evaluation criteria for straight cutability≫
：: The difference between the start of the tear and the position of the cut when the propagation of the tear reaches 100 mm is within 20 mm.
×: The difference between the position of the cut and the position of the cut when the propagation of the tear reaches 100 mm exceeds 20 mm.

<Evaluation criteria for easy opening>
：: Both the evaluation of the opening property and the evaluation of the straight-line cut property were “◎”.
X: At least one of the evaluation of the opening property and the evaluation of the linear cut property is "x".

[Evaluation of blocking resistance]
With respect to the package film of each example, the static friction coefficient and the dynamic friction coefficient were measured in accordance with JIS K 7125-1999, and evaluated according to the following evaluation criteria. As a measuring device, using a friction coefficient measuring device (manufactured by Tester Sangyo Co., Ltd.), at a temperature of 23 ° C. and 50% RH, a test speed of 100 mm / min, a vertical load of 1.96 N and a film for a package with a flat indenter specification. The frictional resistance between them was measured.
In the following evaluation criteria, “◎” is the best, “○” is the next best, and if “◎” and “、”, the blocking when the film for a package is wound up with a roll or the like. Is easily suppressed. “X” indicates that blocking is likely to occur.
：: Both the static friction coefficient and the dynamic friction coefficient are 1.5 or less.
：: Both the static friction coefficient and the dynamic friction coefficient are less than 3.0 and other than “」 ”.
×: at least one of the static friction coefficient and the dynamic friction coefficient is 3.0 or more.

[Comprehensive evaluation]
The above evaluations of oxygen gas barrier properties, sealing properties, impact resistance, and easy-opening properties were all "A", and the overall evaluation was "A".
In the above evaluations of oxygen gas barrier properties, sealing properties, impact resistance, and easy-opening properties, those having one or more "O" and no "x" were evaluated as "O".
In the above evaluations of oxygen gas barrier properties, sealing properties, impact resistance, and easy-opening properties, those having one or more "x" were evaluated as "x".

As shown in Table 3, it was confirmed that the films for packages of Examples 1 to 10 to which the present invention was applied or the packages using the same were excellent in oxygen gas barrier properties, sealing properties, impact resistance, and easy opening properties. did it. The packaging films of Examples 1 to 9 containing the lubricant and the AB agent in the laminate layer and the seal layer in predetermined amounts were also excellent in blocking resistance.
On the other hand, when the packaging film (Comparative Example 1) in which the content of the acid-modified polyolefin in the laminate layer and the seal layer is less than the range of the present invention was used, sufficient openability was not obtained. When a packaging film (Comparative Example 2) in which the content of the acid-modified polyolefin in the laminate layer and the seal layer was more than the range of the present invention was used, sufficient sealing performance and impact resistance were not obtained. Furthermore, sufficient blocking resistance was not obtained. When a film for a package (Comparative Example 3) in which the thickness of the sealant material was less than the range of the present invention was used, sufficient sealing performance and impact resistance were not obtained. When a film for a package (Comparative Example 4) having a thickness of the sealant exceeding the range of the present invention was used, sufficient openability was not obtained. Furthermore, sufficient blocking resistance was not obtained.
From the above results, it was confirmed that by applying the present invention, a film for a package excellent in oxygen gas barrier properties, sealing properties, impact resistance, and easy-openability was obtained.

DESCRIPTION OF SYMBOLS 1 Package film 10 Base material 22 Laminate layer 24 Seal layer 26 Intermediate layer 30 Sealant material

Claims (5)

A film for a packaging body comprising a sealant material including a laminate layer, a seal layer, and an intermediate layer disposed between the laminate layer and the seal layer,
The laminate layer and the seal layer are layers of a mixture of an acid-modified polyolefin and a polyolefin, and include 50 to 70% by mass of the acid-modified polyolefin,
The intermediate layer, an ethylene - a layer containing at least one selected vinyl alcohol polymers and polyvinyl alcohol or al,
A film for a package, wherein the thickness of the sealant is more than 20 μm and less than 130 μm.   The package film according to claim 1, wherein both or one of the laminate layer and the seal layer contains a lubricant and an antiblocking agent.   The package film according to claim 1 or 2, wherein the intermediate layer contains an oxygen absorbent.   The package film according to any one of claims 1 to 3, further comprising a substrate provided on the laminate layer.   A package in which the film for a package according to any one of claims 1 to 4 is formed.

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