Easily breakable film and packaging body

Abstract

Provided is an easy-to-break film which has excellent easy-to-break properties and which has, on the surface thereof, a base material layer containing a cyclic olefin resin, the thickness of the base material layer being 40% or more with respect to the total thickness of the easy-to-break film, said easy-to-break film having excellent easy-to-break properties. Preferably, the base material layer of the easy-to-break film contains a cyclic olefin resin having a glass transition temperature of 60 DEG C or higher. The base material layer is preferably configured from a surface resin layer on the surface side and an inorganic substance-containing layer containing an inorganic substance.

Description

Technical Field

[0001] The invention relates to an easily breakable film and a packaging body. Background Art

[0002] In the packaging of pharmaceuticals such as tablets and capsules, foods, etc., a packaging method called PTP (Press Through Package) is used. This PTP package is usually composed of a blister container and an aluminum film. The blister container is provided with a recessed portion for storing the packaged object on a plate made of a resin system, and the aluminum film is used as a cover material for covering the recessed portion from the back of the blister container after storing the capsule in the recessed portion.

[0003] In pharmaceutical companies, before manufacturing PTP-packaged products, a trial run is conducted using only PTP packaging materials to confirm whether there are any defects in the production line. Therefore, a certain amount of PTP packaging material waste is generated during the trial run. Some of the waste is recycled, but the resin sheet and the aluminum of the lid material are difficult to separate, and are mainly incinerated as industrial waste.

[0004] From the viewpoint of effective utilization of limited resources and reduction of greenhouse gases, it is desired to have a blister container and a lid material with a single resin composition (single material) and to be separately recyclable.

[0005] To date, as a PTP covering laminate film that can be used instead of a PTP covering film using aluminum foil, there has been reported a PTP covering laminate film that has a heat-sealable resin (A) layer, a cyclic olefin resin (B) layer, and a heat-sealable heat-resistant resin (C) layer, wherein these layers are stacked in the order of (A) layer / (B) layer / (C) layer, and the puncture strength of which using a metal needle with a tip diameter of 1 mm is less than 5N (for example, refer to Patent Document 1).

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 11-105217 Summary of the invention

[0009] Problems to be solved by the invention

[0010] The present invention aims to solve the above-mentioned conventional problems and achieve the following objectives: That is, the present invention aims to provide an easily breakable film having excellent breakability and made of a single material.

[0011] Methods for solving problems

[0012] The present invention was completed based on the above findings of the present inventors, and the method for solving the above problems is as follows.

[0013] <1> An easily breakable film, characterized in that it has a substrate layer containing a cyclic olefin resin on its surface, wherein the thickness of the substrate layer is 40% or more of the total thickness of the easily breakable film.

[0014] <2> The easily breakable film according to <1> above, wherein the base layer contains a cyclic olefin resin having a glass transition temperature of 60° C. or higher.

[0015] <3> The easily breakable film according to <1> or <2>, wherein the base layer includes a surface resin layer on the surface side and an inorganic substance-containing layer containing an inorganic substance.

[0016] <4> The easily breakable film according to <3> above, wherein a content of the inorganic substance is 0.1% by mass or more and 10% by mass or less based on a total amount of the easily breakable film.

[0017] <5> The easily breakable film according to any one of <1> to <4>, further comprising a heat seal layer on the surface opposite to the surface.

[0018] <6> The easily breakable film according to any one of <1> to <5>, wherein the extrusion strength when extruded using a jig having a flat plate-shaped tip portion with a diameter of 13 mm is 35 N or less.

[0019] <7> The easily breakable film according to any one of <1> to <6>, further comprising a water vapor and / or oxygen barrier layer.

[0020] <8> The easily breakable film according to <1> above, which is a cover material for a package.

[0021] <9> A package comprising a container having a recessed portion and a cover material, wherein the cover material is the easily breakable film according to any one of <1> to <8>.

[0022] <10> The package according to <9> above, which is for food and beverage packaging or medical use.

[0023] Effects of the Invention

[0024] According to the present invention, the above-mentioned problems of the related art can be solved, the above-mentioned objects can be achieved, and an easily breakable film having excellent easy breakability and made of a single material can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG. 1 is a schematic cross-sectional view showing an example of the easily breakable film of the present invention.

[0026] FIG. 2 is a schematic cross-sectional view showing another example of the easily breakable film of the present invention.

[0027] FIG. 3 is a schematic cross-sectional view showing an example of the package body of the present invention. DETAILED DESCRIPTION

[0028] (Packaging)

[0029] First, the packaging body of the present invention will be described.

[0030] The packaging body of the present invention comprises a container (bottom material) having a recessed portion and a cover material, wherein the cover material is the easily breakable film of the present invention described below. The cover material can be thermally bonded (heat-sealed) to the opening of the container.

[0031] The package body is preferably used for food and beverage packaging or medical use.

[0032] The above-mentioned packaging body is preferably a PTP (Press Through Package, blister packaging). Specifically, the following packaging forms can be cited: it has a container (base material) with multiple independent recesses and a cover material. After the stored objects (also called contents) are stored in the above-mentioned recesses, the cover material is covered, deaeration is performed or replacement is performed with an inert gas, and the contact portion between the container and the cover material is heat-sealed.

[0033] In addition, the above-mentioned packaging body is preferably a packaging body having a container such as a paper bag or a plastic cup and a cover material serving as a straw insertion port. Specifically, the following can be cited: after making a packaging body with the contact portion between the container and the cover material being heat-sealed, a packaging form in which beverages or other objects to be contained are contained in the container portion and sealed; after the container contains the beverages or other objects to be contained, the cover material is covered, deaeration is performed or replacement is performed with an inert gas, and the contact portion between the container and the cover material is heat-sealed, etc.

[0034] The shape of the recess in the packaging body and the sealing width or area between the lid and the container vary depending on the shape and form of the object to be packaged and cannot be uniquely specified. There is no particular limitation and they can be appropriately selected according to the intended application form.

[0035] The package body is preferably used for food and beverage packaging or medical use.

[0036] The pharmaceutical product used for medical treatment is not particularly limited, and a pharmaceutical product in a packaging form using a PTP (Press Through Package) can be appropriately selected according to the purpose, and examples thereof include tablets and capsules.

[0037] The food and beverages are not particularly limited and can be appropriately selected according to the purpose. Examples thereof include: tablet-shaped foods such as supplements, chocolate, ramune, and soft candies; and beverages contained in packaging bodies such as paper bags and plastic cups having lids serving as straw insertion ports.

[0038] (Easy to break film)

[0039] The easily breakable film of the present invention is an easily breakable film having a substrate layer containing a cyclic olefin resin on its surface, wherein the thickness of the substrate layer is 40% or more of the total thickness of the easily breakable film.

[0040] The easily breakable film can be suitably used as a cover material for the package body.

[0041] Here, "easy to break" means that the film is broken and cut when a force is applied, and may be easy to squeeze out or easy to pierce.

[0042] “Easy to squeeze out” means that when force is applied to the film from the outside of the container (bottom material) through the stored object (for example, a tablet), the film is broken and the stored object can be squeezed out.

[0043] The "ease of extrusion" can be evaluated by measuring the extrusion strength when a fixed film is extruded using a jig having a flat-plate-shaped tip (for example, a circular shape with a diameter of 13 mm).

[0044] The extrusion strength of the easily breakable film when extruded using a jig having a circular and flat tip with a diameter of 13 mm is preferably 35 N or less, more preferably 25 N or less, and further preferably 20 N or less. When the extrusion strength is 35 N or less, good extrudability is achieved.

[0045] Specifically, the extrusion strength can be obtained as follows: a film to be measured, such as an easily breakable film, is fixed between two pieces of stainless steel having a hole (diameter: 55 mm) in the center, a fixture having a 13 mm flat front end is extruded toward the film stretched in the hole, and the extrusion strength (compression strength) applied when the film breaks is measured. It should be noted that if the film is not broken, for example, when it is fully extended, or if the extrusion strength exceeds 35 N even if it is broken, it can be judged that it is not an "easy to break film".

[0046] “Easily pierceable” means that when the tip is pressed against the film and force is applied, the film is broken and the tip can penetrate the film. Examples of the tip include the tip of a drinking straw cut obliquely.

[0047] The "ease of piercing" can be evaluated by extruding the fixed film using a jig having a metal needle with a tip diameter of 1 mm, for example.

[0048] The easily breakable film has a substrate layer on the surface. The substrate layer may be a combination of a surface resin layer on the surface side and an inorganic-containing layer containing an inorganic substance, or may be a surface resin layer alone or an inorganic-containing layer alone.

[0049] The easily breakable film preferably further has a heat seal layer on the side opposite to the surface.

[0050] The easily breakable film may further include other layers such as a barrier layer and a printed layer on the surface side of the base material layer.

[0051] One embodiment of the easily breakable film includes at least a base material layer and a heat seal layer, and is laminated in the order of base material layer / heat seal layer.

[0052] Another embodiment of the easily breakable film is an easily breakable film having at least a surface resin layer (A), an inorganic layer (B) and a heat seal layer (C), wherein the surface resin layer (A), the inorganic layer (B) and the heat seal layer (C) are stacked in the order of (A) / (B) / (C).

[0053] The substrate layer or surface resin layer (A) is on the outside of the packaging body, and the heat seal layer (C) is on the inside of the packaging body, forming a heat seal layer with the container (base material).

[0054] The container of the packaging body can be heat-sealed by the heat-seal layer (C) of the easily breakable film.

[0055] The above-mentioned easily breakable film can be suitably used as the easily breakable film for packaging of the present invention.

[0056] The above-mentioned easy-to-break film is preferably a coextruded easy-to-break film having at least a surface resin layer (A), an inorganic substance-containing layer (B) and a heat seal layer (C). In addition, the above-mentioned easy-to-break film is preferably an easy-to-break film having other layers (α) such as a barrier layer and a printing layer on the side of the above-mentioned surface resin layer (A), and is stacked in the order of (α) / (A) / (B) / (C).

[0057] <Base material layer>

[0058] The substrate layer contains a cyclic olefin resin as a main resin component. The resin component may contain an olefin resin having no cyclic structure as required, but is preferably composed of a cyclic olefin resin.

[0059] The substrate layer may be a combination of a surface resin layer and an inorganic substance-containing layer, or may be a surface resin layer alone, or may be an inorganic substance-containing layer alone.

[0060] The substrate layer may be a surface layer on which printing can be provided.

[0061] <<(A) Surface resin layer>>

[0062] The surface resin layer (A) contains a cyclic olefin resin as a main resin component and may contain an olefin resin having no cyclic structure as necessary, but is preferably composed of a cyclic olefin resin.

[0063] The surface resin layer (A) may be a surface layer on which printing can be provided.

[0064] -Cyclic olefin resin-

[0065] The cyclic olefin resin is not particularly limited and may be appropriately selected depending on the intended purpose. Examples of the cyclic olefin resin include norbornene-based polymers, vinyl alicyclic hydrocarbon polymers, and cyclic conjugated diene polymers.

[0066] Examples of the norbornene polymer include ring-opening polymers of norbornene monomers (hereinafter referred to as "COP"), norbornene copolymers obtained by copolymerizing norbornene monomers with olefins such as ethylene (hereinafter referred to as "COC"), and hydrogenated products of COP and COC.

[0067] Among the above-mentioned cyclic olefin resins, norbornene-based polymers are preferred, and hydrogenated products of COP and COC are more preferred.

[0068] The weight average molecular weight of the cyclic olefin resin is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 5,000 to 500,000, more preferably 7,000 to 300,000.

[0069] The norbornene-based polymer and the norbornene-based monomer as a raw material are alicyclic monomers having a norbornene ring.

[0070] Examples of the norbornene monomers include norbornene, tetracyclododecene, ethylidene norbornene, vinyl norbornene, ethylidene tetracyclododecene, dicyclopentadiene, dimethanotetrahydrofluorene, phenyl norbornene, methoxycarbonyl norbornene, methoxycarbonyltetracyclododecene, etc. These monomers may be used alone or in combination of two or more.

[0071] The norbornene-based copolymer is obtained by copolymerizing the norbornene-based monomer and an olefin copolymerizable with the norbornene-based monomer.

[0072] Examples of olefins copolymerizable with the norbornene-based monomers include olefins having 2 to 20 carbon atoms, such as ethylene, propylene, and 1-butene; cycloolefins such as cyclobutene, cyclopentene, and cyclohexene; and non-conjugated dienes such as 1,4-hexadiene. These may be used alone or in combination of two or more.

[0073] The cyclic olefin resin may be a commercially available product or a synthetic product.

[0074] Regarding the above-mentioned commercial products, examples of the ring-opening polymer (COP) of norbornene-based monomers include "ZEONOR" manufactured by ZEON Corporation of Japan; examples of norbornene-based copolymers (COC) include "APEL" manufactured by Mitsui Chemicals, Inc., "TOPAS" manufactured by Polyplastics Co., Ltd., etc.; etc.

[0075] The melt volume flow rate (MVR) of the cyclic olefin resin is not particularly limited and may be appropriately selected depending on the intended purpose. However, when measured under the conditions of a temperature of 230° C. and a load of 2.16 kg, it is preferably 1.0 cm 3 / 10 minutes~50.0cm 3 / 10 minutes, more preferably 1.0 cm 3 / 10 minutes~20.0cm 3 / 10 minutes, more preferably 2.0 cm 3 / 10 minutes~18.0cm 3 / 10 minutes, particularly preferably 2.0 cm 3 / 10 minutes~15.0cm 3 When measured under the conditions of a temperature of 260°C and a load of 2.16 kg, it is preferably 1.0 cm 3 / 10 minutes~50.0cm 3 / 10 minutes, more preferably 1.0 cm 3 / 10 minutes~20.0cm 3 / 10 minutes, more preferably 2.0 cm 3 / 10 minutes~10.0cm 3 / 10 minutes, particularly preferably 2.0 cm 3 / 10 minutes~7.0cm 3 / 10 minutes.

[0076] Here, the melt volume flow rate (MVR) is a value measured at a temperature of 230° C. or 260° C. and a load of 2.16 kg (21.18 N) in accordance with JIS K7210.

[0077] The glass transition temperature (Tg) of the cyclic olefin resin is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 60° C. or higher, more preferably 75° C. or higher.

[0078] Two or more cyclic olefin resins having different Tgs may be used in combination, and the Tg of the cyclic olefin resin having a high Tg is preferably 100° C. or higher, more preferably 125° C. or higher.

[0079] In the above-mentioned easily breakable film, in the case of a form in which the substrate layer contains a cyclic olefin resin and only the surface resin layer is not included in the inorganic substance-containing layer, the content of the cyclic olefin resin with a Tg of 100° C. or higher in the above-mentioned surface resin layer is preferably 50% by mass or more, more preferably 75% by mass or more, and further preferably 90% by mass or more, from the perspective of the easy breakability and excellent rigidity of the obtained easily breakable film.

[0080] In the case where the substrate layer in the easily breakable film is composed of a surface resin layer and an inorganic-containing layer, the content of the cyclic olefin resin with a Tg of 100°C or higher in the surface resin layer and the inorganic-containing layer is preferably 30% by mass or more, and more preferably 40% by mass or more, from the perspective of the easy breakability and excellent rigidity of the obtained easily breakable film.

[0081] The glass transition temperature (Tg) of the cyclic olefin resin is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 200° C. or lower from the viewpoint of being able to produce by coextrusion lamination with other resin layers and from the viewpoint of easy availability of industrial raw materials.

[0082] The glass transition temperature can be measured using a differential scanning calorimeter (DSC) (for example, DSC-7020, manufactured by Hitachi High-Technologies Corporation).

[0083] Norbornene-based copolymers with high glass transition temperatures (for example, Tg above 100°C) sometimes have low tensile strength and are prone to cracking and tearing. Therefore, considering the balance between film-forming properties, traction during slitting, winding adaptability, and lamination strength, high Tg products can be used together with low Tg products with a glass transition temperature of less than 100°C to adjust the physical property balance.

[0084] In particular, when the rigidity is too high and there are problems such as easy tearing and bag breakage due to dropping during transportation, the strength can be improved by adding COC with a Tg of less than 100° C. In addition, olefin resins such as propylene resin and ethylene resin without a cyclic structure that are highly compatible with COC can also be added.

[0085] The thickness ratio of the base material layer is 40% or more, preferably 50% or more, and more preferably 60% or more, relative to the total thickness of the easily breakable film.

[0086] The average thickness of the substrate layer is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 5 μm to 40 μm, more preferably 10 μm to 36 μm.

[0087] The thickness ratio of the surface resin layer (A) is not particularly limited and can be appropriately selected according to the purpose. When the substrate layer is used in combination, the thickness ratio is preferably 10% to 90%, and more preferably 15% to 80% relative to the total thickness of the easily breakable film; when the substrate layer is a surface resin layer alone, the thickness ratio is preferably 40% to 95%, and more preferably 50% to 90%.

[0088] The average thickness of the surface resin layer (A) is not particularly limited and can be appropriately selected according to the purpose. When the substrate layer is used in combination, it is preferably 2 μm to 38 μm, and more preferably 2.5 μm to 35 μm; when the substrate layer is a surface resin layer alone, it is preferably 5 μm to 40 μm, and more preferably 8 μm to 36 μm.

[0089] <<(B) Inorganic material-containing layer>>

[0090] The inorganic substance-containing layer (B) contains a cyclic olefin resin as a main resin component, further contains an inorganic substance, and contains other components as necessary.

[0091] The resin component may contain an olefin resin having no cyclic structure as required, but is preferably composed of a cyclic olefin resin.

[0092] -Cyclic olefin resin-

[0093] As the cyclic olefin resin, the ones described in the substrate layer and the surface resin layer (A) can be appropriately selected.

[0094] -Inorganic matter-

[0095] The above-mentioned inorganic substance is not particularly limited and can be appropriately selected according to the purpose. For example, calcium carbonate, talc, silicon dioxide, aluminum oxide, clay, antimony oxide, aluminum hydroxide, magnesium hydroxide, hydrotalcite, calcium silicate, magnesium oxide, potassium titanate, barium titanate, titanium oxide, calcium oxide, magnesium oxide, manganese dioxide, boron nitride, aluminum nitride, etc. can be mentioned.

[0096] The above-mentioned inorganic substances may be used alone or in combination of two or more.

[0097] Among them, at least one selected from the group consisting of calcium carbonate, silica, alumina, aluminum hydroxide, barium titanate, talc, boron nitride and aluminum nitride is preferred, and at least one selected from the group consisting of calcium carbonate, alumina, aluminum hydroxide and talc is more preferred.

[0098] The particle size, fiber length, fiber diameter and other shapes of the inorganic filler are not particularly limited and can be appropriately adjusted according to the target application. In addition, the surface treatment state of the inorganic filler is not particularly limited either and can be surface-modified with saturated fatty acids, etc., according to the target application.

[0099] The inorganic filler may be used in the form of being pre-blended with the thermoplastic resin or in the form of a masterbatch.

[0100] The content of the inorganic substance is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 0.1% by mass to 10% by mass, and more preferably 1% by mass to 5% by mass, based on the total amount of the easily breakable film.

[0101] When the content is 0.1 mass % or more and 10 mass % or less, the film has excellent breakability and is also good in terms of barrier properties and film formability.

[0102] There is no particular restriction on the thickness ratio of the inorganic-containing layer (B), which can be appropriately selected according to the purpose. When the substrate layer is used in combination, the thickness ratio is preferably 10% to 90%, and more preferably 15% to 50%, relative to the total thickness of the easily-breakable film; when the substrate layer is a single inorganic-containing layer, the thickness ratio is preferably 40% to 95%, and more preferably 50% to 90%.

[0103] The average thickness of the inorganic-containing layer (B) is not particularly limited and can be appropriately selected according to the purpose. When the substrate layer is used in combination, it is preferably 2 μm to 38 μm, and more preferably 2.5 μm to 35 μm; when the substrate layer is a single inorganic-containing layer, it is preferably 5 μm to 40 μm, and more preferably 8 μm to 36 μm.

[0104] <<(C) Heat seal layer>>

[0105] The heat seal layer (C) contains a known thermoplastic resin that imparts heat sealability as a main resin component, and further contains other resins and components as necessary.

[0106] -Resin-

[0107] The thermoplastic resin is not particularly limited and can be appropriately selected from known thermoplastic resins according to the purpose, and examples thereof include α-olefin resins, styrene resins, ester resins, acrylic resins, the above-mentioned cyclic olefin resins, etc. Among them, α-olefin resins are preferred from the viewpoint of being able to impart good heat sealability.

[0108] Examples of the α-olefin resin include homopolymers of α-olefin monomers (polyethylene homopolymers, polypropylene homopolymers, etc.); copolymers containing α-olefin monomers as a main component (propylene-ethylene block copolymers, propylene-ethylene random copolymers, ethylene-butene-1 copolymers, propylene-butene-1 copolymers, etc.), etc. These may be used alone or in combination of two or more.

[0109] The thickness ratio of the heat seal layer (C) is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 20% to 60%, more preferably 30% to 60%, relative to the total thickness of the easily breakable film.

[0110] The average thickness of the heat seal layer (C) is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 4 μm to 28 μm, more preferably 6 μm to 25 μm.

[0111] The heat seal layer is disposed on the base material layer directly or via an arbitrary layer such as an anchor coating layer.

[0112] The heat seal layer (C) may be formed by extruding the resin or the like together with the substrate layer by a coextrusion method or by applying a heat seal agent obtained by dispersing or dissolving the resin or the like in a solvent.

[0113] As such a heat sealant, a commercially available hot melt sealant may be used. The heat sealant may be applied entirely or partially to a desired surface of the outermost surface of the laminate.

[0114] The heat sealant is not particularly limited and may be any type of heat sealant such as a heat sealant in which a thermoplastic resin having heat sealability is dissolved in an organic solvent, a heat sealant in which a thermoplastic resin having heat sealability is dissolved in water or an aqueous organic solvent, or an emulsion type heat sealant in which a thermoplastic resin having heat sealability is dispersed in water or an aqueous organic solvent.

[0115] Examples of the heat-sealable resin include thermoplastic resins such as shellac, rosin, rosin-modified maleic acid resin, rosin-modified phenolic resin, nitrocellulose, cellulose acetate, cellulose acetate propionate, cellulose acetate butyrate, chlorinated rubber, cyclized rubber, vinyl chloride, vinylidene chloride, polyamide resin, vinyl chloride-vinyl acetate copolymer, polyester resin, ketone resin, butyral resin, chlorinated polypropylene resin, chlorinated polyethylene resin, chlorinated ethylene vinyl acetate resin, ethylene vinyl acetate resin, acrylic resin, urethane resin, ethylene-vinyl alcohol resin, styrene maleic acid resin, casein, and alkyd resin. These may be used alone or in combination of two or more.

[0116] There are no particular restrictions on the organic solvent, and it can be appropriately selected according to the purpose. For example, there can be mentioned aromatic hydrocarbons such as toluene, xylene, Solvesso #100, Solvesso #150; aliphatic hydrocarbons such as hexane, heptane, octane, decane; various ester organic solvents such as methyl acetate, ethyl acetate, isopropyl acetate, butyl acetate, amyl acetate, ethyl formate, butyl propionate, etc.

[0117] Examples of the aqueous organic solvent include alcohols such as methanol, ethanol, propanol, and butanol; ketones such as acetone, methyl ethyl ketone, and cyclohexanone; glycol ethers such as ethylene glycol (mono- or di-) methyl ether, ethylene glycol (mono- or di-) ethyl ether, ethylene glycol monopropyl ether, ethylene glycol monoisopropyl ether, monobutyl ether, diethylene glycol (mono- or di-) methyl ether, diethylene glycol (mono- or di-) ethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, triethylene glycol (mono- or di-) methyl ether, propylene glycol (mono- or di-) methyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, and dipropylene glycol (mono- or di-) methyl ether; and the like.

[0118] The heat sealant may further contain other components. Examples of other components include lubricants such as wax and fillers, defoamers, plasticizers, leveling agents, emulsifiers, dispersion stabilizers, surfactants, tackifiers, preservatives, antibacterial agents, rust inhibitors, antioxidants, crosslinking agents, curing agents, curing catalysts, light stabilizers, ultraviolet absorbers, photocatalytic compounds, dyes, inorganic pigments, organic pigments, extender pigments, antistatic agents, and the like.

[0119] The wax is not particularly limited and can be appropriately selected according to the purpose, and examples thereof include polyolefin waxes such as fatty acid amide wax, carnauba wax, polyethylene wax, and polypropylene wax; paraffin wax, Fischer-Tropsch wax, beeswax, microcrystalline wax, oxidized polyethylene wax, and amide wax; coconut oil fatty acid, soybean oil fatty acid, etc. These can be used alone or in combination of two or more.

[0120] By using wax, the anti-blocking property can be improved. Polyethylene wax is preferably used because it can improve the anti-blocking property without reducing the heat sealability.

[0121] The amount of the wax to be blended is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 0.1 to 20% by mass based on the total amount of the thermoplastic resin, and more preferably 3 to 15% by mass from the viewpoint of a balance between heat sealability and anti-blocking properties.

[0122] There is no particular limitation on the filler, and it can be appropriately selected according to the purpose, and examples thereof include silicon dioxide, calcium carbonate, calcium phosphate, talc, urethane beads, acrylic beads, and melamine beads. One of these can be used alone, or two or more of them can be used in combination. It is preferred to use either one or both of silicon dioxide and acrylic beads.

[0123] By using a filler, the anti-blocking property can be improved. In addition, when the laminate of the present invention is stored at high temperature, for example, the heat seal layer can be prevented from flowing out and the film thickness can be reduced.

[0124] The shape of the filler is not particularly limited and can be appropriately selected according to the purpose, but is preferably spherical in nature because it is less affected by thermal deformation and can obtain a stable anti-blocking effect regardless of the dispersion method in the coating film. The average particle size of the filler is appropriately adjusted according to the filler used, and is, for example, 0.5 μm to 10 μm.

[0125] The defoaming agent is not particularly limited and can be appropriately selected according to the purpose. Examples thereof include fatty acid salts, higher alcohol sulfates, liquid fatty oil sulfates, sulfates of aliphatic amines and aliphatic amides, aliphatic alcohol phosphates, sulfonates of dibasic fatty acid esters, fatty acid amide sulfonates, alkyl allyl sulfonates, formalin-condensed naphthalene sulfonates, polyoxyethylene alkyl ethers, polyoxyethylene alkylphenol ethers, polyoxyethylene alkyl esters, sorbitan alkyl esters, polyoxyethylene sorbitan alkyl esters, acrylic polymers, silicone-mixed acrylic polymers, vinyl polymers, and polysiloxane compounds.

[0126] The method for applying the heat sealant is not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include gravure coating, reverse coating, kiss coating, air knife coating, Meyer bar coating, roll coating, and dip coating.

[0127] The heat seal layer may be provided on the entire surface of the laminate, or may be provided only on a portion to be heat-sealed when manufacturing a package.

[0128] After the heat sealant is applied, it is dried to form a heat seal layer. The drying temperature is 50°C to 180°C, and the drying time is about 0.5 seconds to 1 minute. The drying method is not particularly limited, and as an example, hot air drying can be cited. Corona discharge treatment or the like can also be implemented as a post-treatment as needed.

[0129] The amount of the heat sealant applied (solid content) is not particularly limited and can be appropriately selected depending on the purpose. For example, 1.0 g / m 2 ~15.0g / m 2 , preferably 2.0g / m 2 ~10.0g / m 2 , more preferably 2.0 g / m 2 ~8.0g / m 2 .

[0130] When the heat seal layer is provided by coating, an anchor coating layer may be provided below the heat seal layer. The anchor coating layer may use the same resin as the heat seal layer. In addition, the anchor coating layer may be formed by, for example, coating a coating liquid containing a resin on one side of the substrate layer. The average thickness of the anchor coating layer is not particularly limited and may be appropriately selected according to the purpose, but is preferably 1 μm to 10 μm, and more preferably 1 μm to 5 μm.

[0131] In the substrate layer, heat seal layer and other layers, as needed, antifogging agents, antistatic agents, heat stabilizers, nucleating agents, antioxidants, lubricants, anti-blocking agents, release agents, ultraviolet absorbers, colorants, extrusion modifiers and other ingredients can be added within the scope that does not impair the purpose of the present invention.

[0132] <<(α) Other layers>>

[0133] The easily breakable film of the present invention may have other layers (α) such as a water vapor and / or oxygen barrier layer (hereinafter sometimes referred to as a "barrier layer"), a printed layer, an OP varnish layer (also referred to as an "overprint varnish layer", "overcoat layer", or "topcoat layer").

[0134] When the other layer (α) is present, it is preferred that the other layer (α) is a water vapor and / or oxygen barrier layer from the viewpoint of ensuring the required high storage stability when the stored object is a pharmaceutical product, for example.

[0135] Furthermore, the other layer (α) may be a printed layer on which printing of the packaging film can be provided.

[0136] The above-mentioned easily breakable film can be an easily breakable film further having another layer (α) on the surface side of the above-mentioned substrate layer and stacked in the order of (α) / substrate layer / heat sealing layer, or an easily breakable film stacked in the order of (α) / (A) / (B) / (C).

[0137] The other layer (α) may be a single layer or a plurality of layers. The plurality of other layers (α) may have the same composition or different compositions.

[0138] The other layer (α) may be extruded together with the substrate layer and the heat seal layer to form a coextruded easily breakable film laminated in the order of (α) / substrate layer / heat seal layer or (α) / (A) / (B) / (C), or the other layer (α) may be bonded to the substrate layer / heat seal layer or the easily breakable film laminated in the order of (A) / (B) / (C) to form a laminated film laminated in the order of (α) / (A) / (B) / (C). In addition, the other layer (α) may be provided by applying a coating agent or an ink composition.

[0139] The bonding method when laminating the other layer (α) is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include dry lamination, wet lamination, solventless lamination, and extrusion lamination.

[0140] The above-mentioned other layer (α) is not particularly limited and can be appropriately selected according to the purpose. If it is for coextrusion, for example, olefin resins such as propylene resin can be mentioned; if it is for laminated film, for example, unstretched polyester (CPET), unstretched nylon (CNY), unstretched polypropylene (CPP), unstretched polyethylene (CPE), unstretched polystyrene (CPS), expanded polystyrene (EPS), biaxially stretched polyester (OPET), biaxially stretched polypropylene (OPP), ethylene vinyl alcohol copolymer (EVOH), coextruded biaxially stretched polypropylene, biaxially stretched ethylene vinyl alcohol copolymer (EVOH), coextruded biaxially stretched polypropylene coated with polyvinylidene chloride (PVDC), biaxially stretched nylon, etc. can be mentioned.

[0141] In addition, the other layer (α) may be provided between the substrate layer and the heat seal layer, or may be provided on both sides of the substrate layer. Specifically, it may be provided in the following order: substrate layer / (α) / heat seal layer, or (α) / substrate layer / (α) / heat seal layer.

[0142] Specifically, as a structure in which a barrier layer, a printing layer, and an OP varnish layer are provided as another layer (α), the following structures can be mentioned.

[0143] Barrier layer / text printing layer / substrate layer / text printing layer / heat sealing layer

[0144] Barrier layer / text printing layer / solid printing layer / substrate layer / text printing layer / heat sealing layer

[0145] Barrier layer / text printing layer / solid printing layer / substrate layer / solid printing layer / text printing layer / heat sealing layer

[0146] Barrier layer / text printing layer / substrate layer / solid printing layer / text printing layer / heat sealing layer

[0147] OP varnish layer / text printing layer / base material layer / text printing layer / heat sealing layer

[0148] OP varnish layer / text printing layer / solid printing layer / substrate layer / text printing layer / heat sealing layer

[0149] OP varnish layer / text printing layer / solid printing layer / base material layer / solid printing layer / text printing layer / heat sealing layer

[0150] OP varnish layer / text printing layer / base material layer / solid printing layer / text printing layer / heat sealing layer

[0151] OP varnish layer / barrier layer / text printing layer / substrate layer / text printing layer / heat seal layer

[0152] OP varnish layer / barrier layer / text printing layer / solid printing layer / substrate layer / text printing layer / heat sealing layer

[0153] OP varnish layer / barrier layer / text printing layer / solid printing layer / substrate layer / solid printing layer / text printing layer / heat sealing layer

[0154] OP varnish layer / barrier layer / text printing layer / substrate layer / solid printing layer / text printing layer / heat sealing layer

[0155] When the other layer (α) is present, the average thickness of the other layer (α) (the average thickness of the total in the case of a plurality of layers) is not particularly limited and may be appropriately selected depending on the intended purpose.

[0156] -Water vapor and / or oxygen barrier layer (barrier layer)-

[0157] Examples of a method for forming the barrier layer include a method of laminating a film having barrier properties and a method of applying a barrier coating agent to form a coating film layer.

[0158] Among them, the method of preparing a coating layer coated with a barrier coating agent is preferred from the viewpoint of simplicity.

[0159] Examples of the barrier coating agent include coating agents containing polymers such as polyvinyl alcohol (PVOH), ethylene vinyl alcohol (EVOH), polysaccharides, acrylic acid- or methacrylic acid-based polymers, starch or starch derivatives, cellulose nanofibers (CNF), nanocrystalline cellulose (NCC), chitosan, or other cellulose derivatives, hemicellulose, polyvinylidene chloride (PVDC), and the like; and coating agents in which at least any one of the above coating agents is used in combination with an inorganic compound.

[0160] Examples of the inorganic substance include silicon dioxide, aluminum oxide, aluminum flakes, glass flakes, hydrous silicates (layered silicate minerals, etc.), kaolinite-serpentine clay minerals (halloysite, kaolinite, endellite, dickite, nacrite, etc., antigorite, chrysotile, etc.), pyrophyllite-talc group (pyrophyllite, talc, kerolite, etc.), montmorillonite, Clay minerals of the stone group (montmorillonite, beidellite, nontronite, saponite, hectorite, sauconite, magnesite, etc.), clay minerals of the vermiculite group (vermiculite, etc.), mica or clay minerals of the mica group (muscovite, micas such as phlogopite, pearl mica, tetrasilicon mica, taenia mica, etc.), chlorite group (lithium chlorite, aluminum chlorite (sudoite), clinochlore, oolite (chamosite), nickel chlorite, etc.), hydrotalcite, plate-like barium sulfate, boehmite, plate-like inorganic compounds such as aluminum polyphosphate, etc.

[0161] The barrier coating agent is not particularly limited, and a known barrier coating agent can be used according to the purpose. Examples of known barrier coating agents include the "Sunbar" series manufactured by Sun Chemical Co., Ltd. and the polyester barrier coating agent described in Japanese Patent No. 5617831.

[0162] --Inorganic Evaporation Layer--

[0163] Furthermore, the barrier layer may be an inorganic vapor-deposited layer that can be provided for the purpose of imparting gas barrier properties.

[0164] The inorganic deposited layer can be formed using an inorganic substance, an inorganic oxide, various metals, a metal oxide, a metal hydroxide, a metal salt, or the like.

[0165] For example, aluminum, aluminum oxide, silicon dioxide, zinc oxide, magnesium oxide, calcium oxide, manganese oxide, iron oxide, cobalt oxide, nickel oxide, etc. can be used alone, or two or more kinds can be used in combination as in binary deposition of silicon dioxide and aluminum oxide. The inorganic vapor deposition layer can be provided with two or more layers. When the inorganic vapor deposition layer is provided with two or more layers, each can be the same composition or different compositions. From the viewpoint of gas barrier properties, aluminum is preferably used.

[0166] The inorganic vapor deposition layer can be provided on each of the above layers or on a separate substrate by a conventionally known method. As a method for forming the inorganic vapor deposition layer, for example, physical vapor deposition methods (PVD methods) such as vacuum evaporation, sputtering, and ion plating, and chemical vapor deposition methods (CVD methods) such as plasma chemical vapor deposition, thermal chemical vapor deposition, and photochemical vapor deposition can be cited.

[0167] The thickness of the inorganic vapor-deposited layer is preferably 1 nm to 200 nm. When the inorganic vapor-deposited layer is an aluminum vapor-deposited layer, the thickness is more preferably 1 nm to 100 nm, more preferably 15 nm to 60 nm, and more preferably 10 nm to 40 nm. When the inorganic vapor-deposited layer is a silicon dioxide or aluminum oxide vapor-deposited layer, the thickness is preferably 1 nm to 100 nm, more preferably 10 nm to 50 nm, and more preferably 20 nm to 30 nm.

[0168] -Printing layer-

[0169] The printed layer is a layer formed with ink or the like to form a desired pattern in order to impart aesthetic properties, various information related to the stored object, and functionality to the easily breakable film of the present invention as a printed object.

[0170] The printing layer contains a binder resin and a colorant and is formed by printing ink.

[0171] The printed layer may be a single layer or a plurality of printed layers. The single layer may be a text printed layer printed with text or an arbitrary target object, or a solid printed layer. In the case of a plurality of printed layers, a text printed layer may be printed on a solid printed layer or a printed layer printed with a target object, etc., and the ink used in each printed layer may be the same ink, the same composition but different only in colorant, or different in composition.

[0172] --Ink--

[0173] The ink is preferably a liquid printing ink used as a gravure printing ink or a flexographic printing ink. The liquid printing ink is roughly divided into an organic solvent-based liquid printing ink with an organic solvent as the main solvent and an aqueous liquid printing ink with water as the main solvent, but either one can be used in the present invention. In addition, there are so-called front printing inks and back printing inks based on lamination, but either one can be used in the present invention.

[0174] Here, the mainstream organic solvent-based liquid printing ink will be described.

[0175] Examples of the binder resin used in the liquid printing ink include cellulose resins such as nitrocellulose, cellulose acetate propionate (CAP), and cellulose acetate butyrate (CAB), polyamide resins, urethane resins, acrylic resins, vinyl chloride-vinyl acetate copolymer resins, chlorinated polypropylene resins, ethylene-vinyl acetate copolymer resins, vinyl acetate resins, polyvinyl chloride resins, polyester resins, alkyd resins, rosin resins, rosin-modified maleic acid resins, ketone resins, cyclized rubber, chlorinated rubber, butyral, petroleum resins, and the like.

[0176] In addition, a curing agent may be used in combination with the above-mentioned binder resin. As the curing agent, a general curing agent used in organic solvent-based gravure printing ink may be used, and an isocyanate-based curing agent is the most commonly used.

[0177] The amount of the isocyanate compound added is preferably 0.3% by mass to 10.0% by mass, and more preferably 1.0% by mass to 7.0% by mass, based on the solid content of the liquid printing ink, from the viewpoint of curing efficiency.

[0178] The content of the binder resin is preferably 0.15% by mass to 50% by mass, and more preferably 1% by mass to 40% by mass, based on the liquid printing ink.

[0179] --Solvents--

[0180] There are no particular restrictions on the solvent used in the liquid printing ink, and examples thereof include water, toluene, xylene, aromatic hydrocarbon organic solvents such as Solvesso #100 and Solvesso #150, aliphatic hydrocarbon organic solvents such as hexane, methylcyclohexane, heptane, octane and decane, and various ester organic solvents such as methyl acetate, ethyl acetate, isopropyl acetate, n-propyl acetate, butyl acetate, amyl acetate, ethyl formate and butyl propionate. In addition, as water miscible organic solvent, can cite alcohol system such as methanol, ethanol, propanol, butanol, isopropanol; Ketone system such as acetone, methyl ethyl ketone, cyclohexanone; Ethylene glycol (mono, di) methyl ether, ethylene glycol (mono, di) ethyl ether, ethylene glycol monopropyl ether, ethylene glycol monoisopropyl ether, monobutyl ether, diethylene glycol (mono, di) methyl ether, diethylene glycol (mono, di) ethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, triethylene glycol (mono, di) methyl ether, propylene glycol (mono, di) dimethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol (mono, di) methyl ether and other glycol ether system various organic solvents etc.. They can be used alone or in combination of two or more.

[0181] --Colorants--

[0182] The liquid printing ink contains a colorant and can be used as a liquid printing ink containing a colorant used in design printing for the purpose of imparting beautification. As the colorant, inorganic pigments, organic pigments and dyes used in general inks, coatings and recording agents can be cited, and pigments are preferred. As organic pigments, soluble azo series, insoluble azo series, azo series, phthalocyanine series, halogenated phthalocyanine series, anthraquinone series, anthraquinone series, dianthraquinone series, anthrapyrimidine series, perylene series, perirone series, quinacridone series, thioindigo series, dioxazine series, isoindolinone series, quinophthalone series, azomethine series, flavanone series, diketopyrrolopyrrole series, isoindolinone series, indanthrone series, carbon black series and other pigments can be cited. In addition, for example, there can be mentioned Carmine 6B, Lake Red C, Permanent Red 2B, Disazo Yellow, Pyrazolone Orange, Carmine FB, Cromophtal Yellow, Cromophtal Red, Phthalocyanine Blue, Phthalocyanine Green, Dioxazine Violet, Quinacridone Magenta, Quinacridone Red, Indanthrone Blue, Pyrimidine Yellow, Thioindigo Red, Thioindigo Magenta, Perylene Red, Perylene Orange, Isoindolinone Yellow, Nigrosine, Diketopyrrolopyrrole Red, Daylight Fluorescent Pigments, etc. In addition, both non-acid-treated pigments and acid-treated pigments can be used.

[0183] Examples of inorganic pigments include white inorganic pigments such as titanium oxide, zinc oxide, zinc sulfide, barium sulfate, calcium carbonate, chromium oxide, silicon dioxide, lithopone, antimony white, and gypsum. Among inorganic pigments, titanium oxide is particularly preferred. Titanium oxide is white in color and is preferred from the perspectives of coloring power, hiding power, chemical resistance, and weather resistance. From the perspective of printing performance, the titanium oxide is preferably treated with silicon dioxide and / or aluminum oxide.

[0184] Examples of inorganic pigments other than white include aluminum particles, mica, bronze powder, chrome vermilion, chrome yellow, cadmium yellow, cadmium red, ultramarine, Prussian blue, red iron oxide, yellow iron oxide, black iron, and zircon. Aluminum is in the form of powder or paste. It is preferably used in the form of a paste from the viewpoints of handling ease and safety. Whether to use a leafing type or a non-leafing type is appropriately selected from the viewpoints of brightness and density.

[0185] The content of the above-mentioned pigment is preferably an amount sufficient for ensuring the concentration and coloring power of the liquid printing ink, that is, 1% to 60% by mass relative to the total mass of the liquid printing ink, and the weight ratio of the solid content in the liquid printing ink is preferably 10% to 90% by mass. In addition, these pigments can be used alone or in combination of two or more.

[0186] The organic solvent type liquid printing ink may further contain wax, chelate crosslinking agent, extender pigment, leveling agent, defoamer, plasticizer, infrared absorber, ultraviolet absorber, fragrance, flame retardant and the like as required.

[0187] -Biomass liquid printing ink-

[0188] Among the above-mentioned liquid printing inks, in view of the construction of a recycling-oriented society (sustainability) to be continuously developed, liquid printing inks using plant-derived raw materials are preferably used.

[0189] Examples of plant-derived raw materials include cellulose resins such as cellulose acetate propionate resin and nitrocellulose; polyamide resins using dimer acids or polymerized fatty acids derived from natural oils such as soybean oil, palm oil, and rice bran oil; polycarboxylic acids such as succinic acid, succinic anhydride, adipic acid, azelaic acid, sebacic acid, dimer acid, glutaric acid, and malic acid; polyols such as ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, pentanediol, 1,10-dodecanediol, dimer alcohol, and isosorbide; polyisocyanates such as 1,5-pentamethylene diisocyanate and dimer diisocyanate, which are biomass polyurethanes synthesized from plant-derived raw materials; rosin resins, and the like.

[0190] As the biomass liquid printing ink, commercially available products may be used. As commercially available products, inks described in the Japan Organic Resources Association and the like may be used.

[0191] - Anti-UV ink -

[0192] Among the liquid printing inks used in the present invention, it is also preferred to use UV-blocking inks having an ultraviolet shielding effect. As the UV-blocking ink, there is no particular limitation as long as it is an ink having a high ultraviolet shielding effect containing zinc oxide, etc., and commercially available UV-blocking inks can be used.

[0193] -OP Clear Coat-

[0194] The OP varnish layer is a coating used to protect the surface of the cover material from damage and heat.

[0195] As OP varnish, for example, polyvinyl butyral resin can be used; blends of epoxy resins and amino resins; cellulose resins such as nitrocellulose resins, cellulose acetate, cellulose propionate, and cellulose butyrate; polyester resins having benzene rings, and / or alicyclic skeletons such as cyclopentanediol and dihydroxymethyltricyclodecane, such as phthalic acid, naphthalene dicarboxylic acid, and ethylene oxide (hereinafter sometimes referred to as "EO") adducts of bisphenol A; aromatic isocyanates such as diphenylmethane diisocyanate, toluene diisocyanate, xylene diisocyanate, and naphthalene diisocyanate, alicyclic isocyanates such as isophorone diisocyanate and norbornene diisocyanate, and / or carbamate resins formed by combining isocyanurate triisocyanate with polyol and / or tris(2-hydroxyethyl)isocyanurate, etc.

[0196] In addition, as a curing agent for the OP varnish layer, for example, polyisocyanates using the above-mentioned isocyanates can be used. In addition, compounds having a benzene ring and an unsaturated double bond, such as styrene and phenoxydiethylene glycol acrylate; compounds having an alicyclic structure and an unsaturated double bond, such as isobornyl acrylate and dicyclopentanyl acrylate; (meth)acrylates; and other free radical copolymers can also be preferably used.

[0197] The OP varnish layer preferably has heat resistance, and the OP varnish preferably contains a resin having a polymer skeleton such as a cellulose skeleton, a benzene ring skeleton, an isocyanuric ring skeleton, an alicyclic skeleton, etc., whose glass transition temperature (hereinafter sometimes referred to as "Tg") of the polymer is 100°C or higher.

[0198] In addition, a low Tg resin may be mixed and used in consideration of the adhesion to the olefin film.

[0199] In addition, the OP varnish layer may further contain a colorant and be colored.

[0200] The colorant is not particularly limited, and examples thereof include inorganic pigments, organic pigments, and dyes used in general inks and the like used in the above-mentioned printing layer.

[0201] In addition, when the OP varnish layer further contains inorganic fine particles as aggregates, it is preferable because the heat resistance is excellent.

[0202] Examples of the inorganic fine particles include boron nitride, aluminum nitride, aluminum oxide, magnesium oxide, titanium dioxide, zirconium oxide, zinc oxide, silicon oxide, and silicon dioxide (quartz, fumed silica, precipitated silica, silicic anhydride, fused silica, crystalline silica, and ultrafine amorphous silica).

[0203] Among them, boron nitride, aluminum nitride, aluminum oxide, titanium dioxide, magnesium oxide, zinc oxide, silicon oxide, and the like are preferred because of their excellent thermal conductivity.

[0204] The inorganic fine particles may be used alone or in combination of two or more.

[0205] The primary particle size of the inorganic fine particles is preferably 5 nm to 200 nm, more preferably 10 nm to 100 nm. If the primary particle size is 5 nm or more, the inorganic fine particles in the dispersion are well dispersed, and if it is 200 nm or less, the strength of the cured product is good.

[0206] The OP varnish layer may further contain at least any one of wax, silicone additives and organic beads in order to prevent damage to the coating film, prevent blocking during laminate formation, and impart processability during bag making after laminate production.

[0207] Examples of the wax include amide wax, polypropylene wax, polyethylene wax, paraffin wax, carnauba wax, rice bran wax, etc. Examples of the silicone additive include ethylene oxide (EO) adducts of dimethylsiloxane, silicone modified products, etc. Examples of the organic beads include organic beads made of acrylic, nylon, polyurethane, or epoxy.

[0208] The solvent used in the coating agent for forming the OP varnish layer is not particularly limited, and the same solvents as those used in the above-mentioned printing ink can be used.

[0209] [Method for producing easily breakable film]

[0210] As the manufacturing method of the easy-to-break film of the present invention, there is no particular limitation, for example, the following method can be cited: each resin or resin mixture used in each layer is heated and melted with different extruders, and the surface resin layer (A) / inorganic layer (B) / heat-sealing layer (C) or the surface resin layer (A) monomer or inorganic layer (B) monomer / heat-sealing layer (C) are laminated in a molten state by a co-extrusion multilayer die method, a feed block method, etc., and then a co-extrusion method that is molded into a film-like shape is utilized, such as inflation, a T-die cooling roll method, etc. The co-extrusion method can relatively freely adjust the ratio of the thickness of each layer, and a multilayer film having excellent sanitation and excellent cost performance can be obtained, so it is preferred. In the case of a resin having a large difference between the lamination melting point and Tg, the film appearance is sometimes deteriorated during co-extrusion processing, or it is difficult to form a uniform layer structure. In order to suppress such deterioration, a T-die cooling roll method that can be melt-extruded at a relatively high temperature is preferably used.

[0211] When the heat seal layer is formed using the heat seal agent, after obtaining the laminated body other than the heat seal layer, the surface resin layer (A) alone or the inorganic material-containing layer (B) alone, the heat seal layer may be provided by applying the heat seal agent by the above method.

[0212] Furthermore, when printing or laminating is performed on a surface different from the heat seal layer (C), in order to improve adhesion to printing ink, adhesives, etc., it is preferred that a surface treatment be performed on the surface different from the heat seal layer (C). Examples of such surface treatments include surface oxidation treatments such as corona treatment, plasma treatment, chromic acid treatment, flame treatment, hot air treatment, ozone and ultraviolet treatment, or surface unevenness treatments such as sandblasting. Among these, corona treatment is preferred.

[0213] The exposed surface on the heat seal layer (C) side may be subjected to surface treatment.

[0214] <Container (base material)>

[0215] There are no particular restrictions on the above-mentioned container (base material), and a known container can be appropriately selected according to the purpose. If it is a PTP method, a resin-molded container is preferably used. If it is a container for beverages, a paper bag, plastic cup, etc. that can be heat-sealed with a cover material of a straw mouth is preferably used.

[0216] The resin is not particularly limited, and a known heat-sealable olefin resin may be appropriately selected according to the intended purpose.

[0217] The packaging body of the present invention comprises a cover material and a container having a recessed portion, wherein the cover material can be heat-bonded (heat-sealed) to the opening of the container, and the recessed portion can be sealed by heat-sealing the cover material and the container.

[0218] Alternatively, in the case of a packaging body such as a paper bag for beverages in which the lid member and the container are heat-sealed in advance, the object to be stored may be stored in the packaging body and then sealed.

[0219] The method for producing the easily breakable film is not particularly limited, and a known method may be appropriately selected depending on the intended purpose. Examples of the method include coextrusion and lamination.

[0220] As the above-mentioned co-extrusion method, for example, the following method can be cited: extruding from a T-die at an extrusion temperature (for example, 250°C) so that the thickness of each layer of the substrate layer (or the above-mentioned surface resin layer (A) and the above-mentioned inorganic substance-containing layer (B)) and the above-mentioned heat seal layer (C) becomes a predetermined ratio, cooling with a water-cooled metal cooling roller (for example, 40°C), performing corona discharge treatment as needed, winding on a roller, and aging in an aging room (for example, 40°C) (for example, 24 hours).

[0221] There are no particular restrictions on the method for manufacturing the above-mentioned container with a recessed portion, and a known method can be appropriately selected according to the purpose. For example, there can be mentioned a method of using a mold having a specific shape (for example, conforming to the shape of the object to be contained) to form a container having a recessed portion capable of containing the object to be contained from a sheet-like film.

[0222] The shape and number of the recesses in the packaging body, and the sealing width or area of ​​the cover material and the container vary depending on the shape and form of the object to be stored, cannot be uniquely specified, are not particularly limited, and can be appropriately selected according to the target application form.

[0223] There is no particular limitation on the method for heat-sealing the cover material and the container, and a known method may be appropriately selected according to the purpose. For example, the following method may be mentioned: after storing the stored object in the recessed portion of the container, the cover material is placed on the container, deaerated or replaced with an inert gas, and the contacting portion of the cover material and the container is heat-sealed.

[0224] The heat sealing is not particularly limited and can be performed using a known heat sealing packaging machine according to the purpose. The molding heating temperature and molding time during the heat sealing are not particularly limited and can be appropriately selected according to the purpose, for example, 80°C to 180°C and 0.1 second to 5.0 seconds can be cited.

[0225] The easily breakable film 10 in this embodiment is composed of a surface resin layer (A) 1, an inorganic substance-containing layer (B) 2, and a heat seal layer (C) 3, and is an easily breakable film stacked in the order of (A) / (B) / (C), as shown in FIG. 1 .

[0226] In addition, as shown in Fig. 2, the easily breakable film 10 in another embodiment may be an easily breakable film further having another layer (α) 4 on the side of the surface resin layer (A) 1, and stacked in the order of (α) / (A) / (B) / (C). The other layer (α) 4 may be a single layer or a plurality of layers.

[0227] Fig. 3 is a schematic cross-sectional view showing an example of a package in this embodiment. The package 100 is a package having a cover 20 and a container 30 having recesses, and can accommodate contents 40 (such as tablets) individually in a plurality of independent recesses, and can take out each content by squeezing out.

[0228] The cover material 20 of the package body 100 is the easily breakable film 10 , and the heat seal layer (C) 3 of the easily breakable film 10 is heat-sealed to the container 30 .

[0229] [Example]

[0230] Hereinafter, the present invention will be described in more detail based on Examples, but the present invention is not limited to the following Examples.

[0231] (Example 1)

[0232] <Production of easy-to-break film for lid material>

[0233] As the resin for the surface resin layer (layer A), a ring-opening polymer of a norbornene-based monomer (hereinafter referred to as "cyclic olefin resin (a)") was used. MVR: 4 cm 3 / 10 minutes (260°C, 2.16kg), density: 1.02g / cm 3 , glass transition temperature: 158°C) 50 parts by mass, and a ring-opening polymer of a norbornene-based monomer (hereinafter referred to as "cyclic olefin resin (b)". MVR: 12 cm 3 / 10 minutes (230°C, 2.16kg), density: 1.02g / cm 3 , glass transition temperature: 78°C) 50 parts by mass.

[0234] As the resin for the inorganic substance-containing layer (layer B), 50 parts by mass of the same cyclic olefin resin (a) and 30 parts by mass of the cyclic olefin resin (b) as those for layer A, and 20 parts by mass of a masterbatch containing 40% by mass of talc as an inorganic substance were used.

[0235] As the resin for the heat seal layer (C layer), polypropylene (hereinafter referred to as "propylene resin (a)") was used. MFR: 6 g / 10 min (230°C, 21.18 N), density: 0.89 g / cm 3 )100 parts by mass.

[0236] By a co-extrusion method, layers (A) / (B) / (C) were laminated from a T die at an extrusion temperature of 250°C, extruded in a manner such that the thickness ratio of each layer was 20% / 30% / 50%, cooled with a 50°C water-cooled metal cooling roll, and subjected to a corona discharge treatment in a manner such that the wetting tension of the surface resin layer (A) became 40 mN / m. The film was then wound on a roll and aged in an aging chamber at 40°C for 24 hours to obtain an easily breakable film 1 of Example 1 which is a co-extruded laminated film having a total thickness of 30 μm.

[0237] The content of the inorganic substance was 2.4% by mass based on the total amount of the easily breakable film.

[0238] <Production of packaging>

[0239] As the container (base material), a container having independent recesses for storing tablets was used, which was obtained by vacuum-compression molding of a molded resin sheet.

[0240] Next, after the tablets were placed in the recessed portion of the container, the heat seal layer (C layer) of the easily breakable film 1 was adhered and fixed to the base material with a double-sided tape so as to contact the container, thereby obtaining the package body 1 of Example 1.

[0241] <Evaluation>

[0242] The produced easily breakable film 1 and package 1 were evaluated as follows.

[0243] <<Extrusion Strength>>

[0244] The easily breakable film 1 was fixed between two stainless steel sheets having a hole (diameter: 55 mm) in the center, and a jig having a circular and flat front end with a diameter of 13 mm was pressed toward the film stretched in the hole to measure the extrusion strength (compression strength) applied when the easily breakable film 1 was broken.

[0245] In addition, when the film does not break, for example, when it is completely stretched, or when the extrusion strength exceeds 35N even if it breaks, it is judged not to be an "easy to break film".

[0246] The results are shown in Table 1.

[0247] <<Push-through property>>

[0248] The container (bottom material) of the produced package 1 was pressed with a finger to take out the tablets as the contents, and the tablets were evaluated according to the following criteria.

[0249] [Evaluation criteria]

[0250] ◎: The contents can be taken out with the same extrusion force as commercially available PTP of aluminum foil type without getting stuck in the broken lid material (good opening)

[0251] ○: The extrusion force is strong or the bottle is stuck, but the contents can be taken out (can be opened)

[0252] ×: The extrusion force is large and the product gets stuck, making it difficult to remove the contents (difficult to open).

[0253] (Examples 2 to 6)

[0254] In Example 1, as shown in Table 1, the resin composition and the extrusion conditions of the co-extrusion method were changed, and the thickness of each layer (A) / (B) / (C) was changed. In addition, the easily breakable films 2 to 6 for lid materials and packaging bodies 2 to 6 of Examples 2 to 6 were prepared in the same manner as in Example 1, and these evaluations were carried out.

[0255] In addition, the Examples and Comparative Examples in which the column of the resin composition of the inorganic substance-containing layer (B) is blank have a layer structure of (A) / (C) without including the inorganic substance-containing layer (B).

[0256] (Comparative Examples 1 to 6)

[0257] In Example 1, as shown in Table 2, the resin composition and the extrusion conditions of the co-extrusion method were changed, and the thickness of each layer (A) / (B) / (C) was changed. In addition, the easily breakable films a~f for lid materials and packaging bodies a~f of Comparative Examples 1~6 were prepared in the same manner as in Example 1 and these evaluations were carried out.

[0258] In Table 2, "propylene resin (b)" has MFR: 2.5 g / 10 min (230°C, 21.18 N), density: 0.90 g / cm 3 of polypropylene.

[0259] In addition, the Examples and Comparative Examples in which the column of the resin composition of the inorganic substance-containing layer (B) is blank have a layer structure of (A) / (C) without including the inorganic substance-containing layer (B).

[0260] [Table 1]

[0261]

[0262] [Table 2]

[0263]

[0264] Explanation of symbols

[0265] 1Surface resin layer (A)

[0266] 2Inorganic layer (B)

[0267] 3. Heat sealing layer (C)

[0268] 4 Other layers (α)

[0269] 10Easy to break film

[0270] 20 Cover material

[0271] 30 containers

[0272] 40 things to be stored (contents)

[0273] 100 packing

[0274] This international application claims the benefit of priority based on Japanese Patent Application No. 2022-125223 filed on August 5, 2022, the entire contents of which are incorporated herein by reference.

Claims

1. An easily breakable film, characterized in that: The surface of the film has a substrate layer containing a cyclic olefin resin, and the thickness of the substrate layer is 40% or more relative to the total thickness of the easily breakable film. 2 . The easily breakable film according to claim 1 , wherein the base layer comprises a cyclic olefin resin having a glass transition temperature of 60° C. or higher. 3 . The easily breakable film according to claim 1 , wherein the base layer is composed of a surface resin layer on the surface side and an inorganic substance-containing layer containing an inorganic substance. 4 . The easily breakable film according to claim 3 , wherein a content of the inorganic substance is 0.1% by mass or more and 10% by mass or less relative to a total amount of the easily breakable film. The easily breakable film according to claim 1 , further comprising a heat seal layer on a surface opposite to the surface. The easily breakable film according to claim 1, wherein the extrusion strength thereof is 35 N or less when extruded using a jig having a flat plate-shaped tip portion with a diameter of 13 mm. The easily breakable film according to claim 1 , further comprising a water vapor and / or oxygen barrier layer. The easily breakable film according to claim 1 , which is a cover material for a packaging body.

9. A packaging body, characterized in that: A container having a recessed portion and a cover member are provided, wherein the cover member is the easily breakable film according to any one of claims 1 to 8. 10 . The package according to claim 9 , which is used for packaging food or beverages or for medical purposes.

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