JP2012214254A - Packaging material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a packaging material that has superior robustness, heat resistance and formability and hardly generates cracks at a bent portion after press-forming and heat-sealing.SOLUTION: In the packaging material where at least a base layer 6, a metal foil layer 7, an adhesive layer 9 and a thermally-adhesive resin layer 8 are sequentially laminated, at least one of the adhesive layer 9 or the thermally-adhesive resin layer 8 includes a polyolefin resin layer where an olefinic elastomer resin is added.

Description

  The present invention relates to a packaging material exhibiting excellent toughness, heat resistance, and moldability.

In recent years, various methods for hermetically storing contents using a packaging material made of a multilayer film composed of a base material layer, a metal foil, an adhesive layer, and a heat-adhesive resin layer as a container have been proposed. Specifically, there is a pouch type in which a pouch is formed from the packaging material having the above configuration and the contents are stored, or an emboss type in which the packaging material is pressed to form a recess and the content is stored in the recess. It is done.

FIG. 8A is a perspective view showing a pouch-type container using the pillow-shaped packaging material 5, and FIG. 8B is a container in which the contents are sealed and stored using the stand-back-shaped packaging material 5. FIG. 8C is a perspective view showing a container in which the contents are sealed and stored using a tray and a sheet on which an embossed portion is formed. In the figure, the hatched area indicates the heat sealed area.

  Containers made of these multilayer films are injected with highly permeable contents such as volatile substances such as alcoholic beverages, bathing agents, perm liquids, cleaning agents, developing solutions, alkaline substances, and surfactants from the openings, The opening is heat sealed to seal the contents inside. At this time, the packaging material needs to have sealing properties and barrier properties such as oxygen and flavor.

  However, in an embossed type packaging material container, when a metal foil with excellent stretchability, such as aluminum, is used during the press molding of the packaging material, the elongation of the innermost thermal adhesive resin layer catches up with the stretching of the aluminum. In some cases, aluminum and the heat-adhesive resin layer were peeled off or cracks were generated in the heat-adhesive resin layer. In addition, when the heat-sealed portion of the embossed type and pouch type packaging material container is heat-sealed and the heat-sealed portion around the packaging material is folded, the heat-adhesive resin layer is once melted and recrystallized at the time of heat-sealing. Load may occur and cracks may occur.

  At this time, a volatile substance, an alkaline substance or a surfactant as a content permeates from the cracked part, and the metal foil and the heat-adhesive resin layer or the metal foil and the adhesive layer are separated, and the packaging is performed. There was a problem that the sealing inside the material could not be maintained.

  Conventionally, in order to solve this problem, a polyolefin in which a functional group having polarizability that has been thermally melted is introduced into an adhesive layer of a multilayer film composed of a base layer, a metal foil, an adhesive layer, and a heat-adhesive resin layer. A resin using a resin has been proposed (see Patent Document 1). However, even this packaging material was insufficient to prevent the occurrence of the cracks.

JP-A-9-58700

  Then, in view of the said problem, this invention aims at providing the packaging material which is excellent in toughness, heat resistance, and a moldability, and is hard to generate | occur | produce a crack in the bending site | part after press molding and heat sealing.

  In order to achieve the above object, the first configuration of the present invention is the packaging material in which a base material layer, a metal foil layer, an adhesive layer, and a heat-adhesive resin layer are at least sequentially laminated. At least one of the agent layer or the heat-adhesive resin layer is a packaging material including a polyolefin resin layer to which an olefin elastomer resin is added.

  The packaging material of the second configuration of the present invention is characterized in that the adhesive layer is made of an acid-modified polyolefin resin.

  In the packaging material of the third configuration of the present invention, the adhesive layer is made of acid-modified polypropylene, the thermal adhesive resin layer is made of a propylene resin, and the olefin elastomer resin is a propylene elastomer resin. Features.

  According to the 1st structure of this invention, toughness, heat resistance, and a moldability improve because a heat bondable resin layer contains the polyolefin resin layer to which the olefin elastomer resin was added. Thereby, even after the heat-adhesive resin layer is crystallized by seal heating, it is possible to maintain a certain toughness and prevent the occurrence of cracks in the bent portion after heat sealing. Moreover, it can prevent that the content inside a packaging material container osmose | permeates a metal foil layer from the cracked location, and a metal layer and a thermoadhesive resin layer peel.

  Further, since the heat-adhesive resin layer has a certain toughness, it is possible to prevent the metal foil and the heat-adhesive resin layer from peeling or cracking when the packaging material is pressed.

  Moreover, the toughness, heat resistance, and moldability of the adhesive layer are improved by including the polyolefin resin layer to which the olefin-based elastomer resin is added. Thereby, even after the adhesive layer is crystallized by seal heating, a certain toughness can be maintained, and the occurrence of cracks in the adhesive layer at the folded site after heat sealing can be prevented. Also, even if a crack occurs in the heat-adhesive resin layer, the adhesive layer prevents the contents inside the packaging material container from penetrating through the cracked portion and coming into contact with the metal foil layer, Peeling of the heat adhesive resin layer can be prevented.

  Further, since the adhesive layer has a certain toughness, it is possible to prevent the metal foil and the heat-adhesive resin layer from peeling off or cracking when the packaging material is pressed. When both the heat-adhesive resin layer and the adhesive layer include a polyolefin resin layer to which an olefin-based elastomer resin is added, a packaging material that is further excellent in moldability, toughness, and heat resistance can be provided.

  According to the second configuration of the present invention, by using the acid-modified polyolefin resin for the adhesive layer, the metal foil layer and the heat-adhesive resin layer can be more firmly bonded and delamination can be prevented.

  According to the third configuration of the present invention, a propylene-based resin is used for the adhesive layer and the heat-adhesive resin layer, and a propylene-based elastomer resin is used for the olefin-based elastomer resin to be added, and each layer is configured with the propylene-based resin. Thereby, the adhesive strength of each layer is further improved, and delamination can be prevented.

(A) The perspective view which shows typically the container using the packaging material which concerns on this invention from upper direction, (b) The perspective view which shows typically the container using the packaging material which concerns on this invention from the back side. . These are exploded perspective views showing a container using the packaging material according to the present invention. These are sectional drawings which show the layer structure of the packaging material which concerns on this invention. These are the perspective views of the apparatus used with the insulation evaluation method used in Example 1. FIG. These are the tables | surfaces which show the insulation evaluation result of Example 1. FIG. These are sectional drawings which show the simulation method used in order to perform the insulation evaluation of Example 2. FIG. These are the tables | surfaces which show the insulation evaluation result of Example 2. (A) Perspective view showing a pouch-type container using a pillow-shaped packaging material, (b) Perspective view showing a container in which contents are sealed and stored using a stand-back-shaped packaging material, (c) Embossed portion It is a perspective view which shows the container which stored the content hermetically using the tray and sheet | seat in which it was formed.

The present invention is a packaging material excellent in toughness, heat resistance and moldability. The packaging material will be described in more detail with reference to the drawings.
[First Embodiment]

  Fig.1 (a) is a perspective view which shows the container 1 which processed the packaging material 5 which concerns on this embodiment into the emboss type, and enclosed the chemical | medical agent with high volatility inside from the upper part, FIG.1 (b) is the container It is a perspective view which shows the back surface side of 1. FIG.

  2 is an exploded perspective view of the container 1 of FIG. 1. When the contents are sealed and stored in the container 1 using the packaging material 5, the overlapping surfaces are substantially the same when folded in half. A sized packaging material 5 is prepared, a tray 5t having a predetermined area on one surface is pressed, the contents are put into the tray 5t, the packaging material 5 is folded in two (FIG. 2, arrow direction), and the peripheral portion Heat seal 5a (see FIG. 1) and seal the inside.

  FIG. 3 is a cross-sectional view showing the layer structure of the packaging material 5 according to this embodiment. In the packaging material 5 according to this embodiment, a base material layer 6 is provided as an outermost layer, a heat-adhesive resin layer 8 is provided as an innermost layer, and a metal foil 7 is disposed therebetween, and the heat-adhesive resin layer 8 and the metal foil 7 are adhesive layers. It adhere | attaches through the acid-modified polyolefin layer 9 which is.

  Here, the heat-adhesive resin layer 8 according to the present embodiment uses an unstretched polypropylene film (hereinafter referred to as a CPP film) to which a propylene-based elastomer resin is added. A CPP film to which a propylene-based elastomer resin is added as compared with a normal CPP film has improved toughness, heat resistance, and moldability. Therefore, even when the packaging material 5 is press-molded in the manufacturing process of the container 1, thermal bonding is performed. Cracks are unlikely to occur in the resin layer 8. In addition, cracking is unlikely to occur when the sealing portion is bent after heat sealing.

  Moreover, when heat-sealing a CPP film to which a propylene-based elastomer resin is added, sufficient sheet strength can be obtained even if heat-sealing at a temperature lower than the melting point of the CPP film to which no propylene-based elastomer resin is added. For this reason, the sealing time can be shortened, the heat sealing process can be simplified, and the production efficiency of the container 1 can be increased.

  When the propylene elastomer resin is added in an amount of 3% by weight to 30% by weight with respect to the polypropylene resin, the physical property function of the CPP film can be most improved.

  Further, in this embodiment, a CPP film in which a propylene-based elastomer resin is added to the heat-adhesive resin layer 8 is used, but a polyolefin resin film having heat adhesiveness can be used in addition to the CPP film.

  At this time, the polyolefin resin film needs to be selected in a timely manner according to the use of the packaging material. However, as the polyolefin resin film to which the propylene-based elastomer resin is added, the linear low-density polyethylene or the medium-density polyethylene resin is propylene-based. A film in which an elastomer resin is added, or a film in which a propylene-based elastomer resin is added to a blend resin of linear low density polyethylene and medium density polyethylene is conceivable.

  In addition, for each type of polypropylene, that is, random propylene, homopropylene, block propylene, linear low density polyethylene and medium density polyethylene, low crystalline ethylene-butene copolymer, low crystalline propylene-butene copolymer Even a terpolymer composed of a three-component copolymer of ethylene, butene and propylene, silica, zeolite, an antiblocking agent (AB agent) such as acrylic resin beads, a fatty acid amide slip agent, or the like may be used. Good.

Further, the heat-adhesive resin layer 8 is not limited to a single layer configuration, and the above films can be laminated to have a multilayer configuration. Therefore, a CPP film in which a propylene-based elastomer resin is mixed with a multilayer polypropylene film composed of various types of polypropylene such as random propylene, homopropylene, and block propylene is included in the lamination, and the durability, toughness, and heat resistance of the heat-adhesive resin layer 8 are included. The physical properties such as properties can be enhanced.

Further, the toughness is further improved by including an ethylene / propylene random copolymer having excellent rigidity in the laminate. This is because ethylene / propylene random copolymer is a copolymer of ethylene and propylene, and the arrangement of repeating units of ethylene and propylene is irregularly polymerized. It is because it is very excellent in toughness compared with these.

  Next, the acid-modified polyolefin layer 9 will be described. The acid-modified polyolefin layer 9 is an adhesive layer provided to bond the metal foil 7 and the heat-adhesive resin layer 8. In this embodiment, a propylene-based elastomer resin is added to the acid-modified polyolefin layer 9. An acid-modified polypropylene resin is used.

  By adding a resin containing a propylene-based elastomer resin to the acid-modified polypropylene resin, it is possible to give flexibility, improve bending resistance, and prevent cracking during molding. Even when a crack occurs in the adhesive resin layer 8, it is possible to prevent the occurrence of cracks in the acid-modified polyolefin layer 9, and to prevent the metal foil 7 and the heat-adhesive resin layer 8 from peeling off.

When using acid-modified polypropylene,
(1) A homotype having a bigat softening point of 115 ° C or higher and a melting point of 150 ° C or higher,
(2) A copolymer of ethylene-propylene having a bigat softening point of 105 ° C or higher and a melting point of 130 ° C or higher (random copolymer type)
(3) A simple substance or a blended product obtained by acid-modified polymerization using an unsaturated carboxylic acid having a melting point of 110 ° C. or higher can be used.

  In addition to the acid-modified polypropylene resin used in this embodiment, the resin constituting the acid-modified polyolefin layer 9 may be a polyolefin resin graft-modified with an unsaturated carboxylic acid, ethylene, acrylic acid, or methacrylic acid. There are polymers, or metal cross-linked polyolefin resins, etc., if necessary, butene component, ethylene-propylene-butene copolymer, amorphous ethylene-propylene copolymer, propylene-α-olefin copolymer, etc. You may add 5% or more.

  Further, instead of providing the acid-modified polyolefin layer 9 as the adhesive layer, the metal foil 7 and the heat-adhesive resin layer 8 can be bonded by a dry lamination method using a fluorine resin layer.

  The fluorine-based resin layer is a layer formed of a fluorine-containing copolymer containing a hydroxyl group and a curing agent that reacts with the fluorine-containing copolymer. The fluorine-containing copolymer containing a hydroxyl group is soluble in an organic solvent and has a crosslinking site in the molecule, and examples of the crosslinking site include an alcoholic hydroxyl group (OH group).

  Next, the base material layer 6 will be described. The base material layer 6 according to the present embodiment uses a stretched nylon film, and the nylon is a polyamide resin, that is, nylon 6, nylon 6,6, a copolymer of nylon 6 and nylon 6,6, nylon 6,10. And polymetaxylylene adipamide (MXD6). In addition to the nylon film, stretched polyester may be used. Examples of the polyester resin include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, copolymerized polyester, and polycarbonate.

In addition, the base material layer 6 can be laminated with films of different materials in addition to the polyester film or nylon film in order to improve pinhole resistance and insulation when the packaging material 5 is used as a container. is there. When making the base material layer 6 into a laminated body, it is preferable that a base material layer contains at least 1 resin layer of 2 or more layers, and the thickness of each layer is 6-25 micrometers. Examples of laminating the base material layer include the following 1) to 7) although not shown.
1) Stretched polyethylene terephthalate / stretched nylon 2) Stretched nylon / stretched polyethylene terephthalate 3) Fluorine-based resin / stretched polyethylene terephthalate (Fluorine-based resin is formed into a film or dried after liquid coating)
4) Silicone resin / stretched polyethylene terephthalate (silicone resin is a film or formed by drying after liquid coating)
5) Fluorine-based resin / stretched polyethylene terephthalate / stretched nylon 6) Silicone-based resin / stretched polyethylene terephthalate / stretched nylon 7) Acrylic resin / stretched nylon (Acrylic resin is film-like or cured after drying by liquid coating)

  In addition, as shown in 3) to 7), the purpose is to ensure the mechanical suitability of packaging material 5 (stability of conveyance in packaging machines and processing machines) and surface protection (heat resistance, content resistance). In order to reduce the frictional resistance between the press mold and the base material layer, or to protect the base material layer when the contents adhere, the base material layer is multilayered and the surface of the base material layer is fluorinated. It is preferable to provide a resin layer, an acrylic resin layer, a silicone resin layer, a polyester resin layer, a blended material layer thereof, and the like.

  The same effect can be obtained when stretched polybutylene terephthalate or polyethylene naphthalate is used in place of the stretched polyethylene terephthalate.

  Next, the metal foil 7 will be described. The metal foil 7 is a layer for preventing water vapor from entering the inside of the packaging material from the outside, stabilizes the pinhole and processability (pouching, press formability) of the metal foil layer alone, and is resistant to pinning. In order to have a hole, a metal such as aluminum or nickel having a thickness of 15 μm or more, or a film on which an inorganic compound such as silicon oxide or alumina is deposited may be used. The aluminum is 80 μm.

  In order to further improve the generation of pinholes and press the packaging material, the aluminum material used as the metal foil 7 has an iron content of 0.3-9. By setting the content to 0% by weight, preferably 0.7 to 2.0% by weight, the aluminum is more malleable than an aluminum containing no iron, and the occurrence of pinholes due to bending as a packaging material is small. In addition, the side wall can be easily formed during press molding. When the iron content is less than 0.3% by weight, effects such as prevention of pinholes and improvement of press formability are not recognized, and the iron content of the aluminum exceeds 9.0% by weight. In this case, the flexibility as aluminum is hindered, and the bag-making property as a packaging material is deteriorated.

  In addition, aluminum produced by cold rolling changes its flexibility, waist strength and hardness under annealing (so-called annealing treatment) conditions, but the aluminum used in the present invention is harder than the non-annealed hard-treated product. Aluminum which tends to be soft with some or complete annealing is preferred. The degree of flexibility, waist strength, and hardness of aluminum, that is, the conditions for annealing, may be appropriately selected according to workability (pouching, press molding).

  Moreover, the adhesive strength with the adhesive 15 improves by performing a chemical conversion treatment on the front and back surfaces of the aluminum that is the metal foil 7.

  The chemical conversion treatment layer can stably bond the acid-modified polyolefin layer 9 and the metal foil 7 and prevent delamination of the metal foil 7 and the heat-adhesive resin layer 8. It also has the function of preventing aluminum corrosion.

  Specifically, delamination is prevented between the metal foil 7 and the heat-adhesive resin layer 8 during press molding by forming an acid-resistant film such as phosphate, chromate, fluoride, triazine thiol compound, etc. In addition, the adhesion (wetability) of the aluminum surface can be improved.

  In addition, for each of the above layers, corona treatment, blast treatment, and oxidation treatment are appropriately performed for the purpose of improving and stabilizing film forming properties, lamination processing, and final product secondary processing (pouching, press molding) suitability. Surface activation treatment such as ozone treatment may be performed.

  Next, the lamination | stacking method of the packaging material 5 which concerns on this embodiment is demonstrated. The lamination method of the metal foil 7 and the heat-adhesive resin layer 8 is roughly classified into a dry lamination method and a thermal lamination method. Here, the dry lamination method is excellent in productivity because it is laminated using an adhesive, but has a high moisture permeability from the cross section of the adhesive layer, and there is a possibility that the moisture that has entered from the cross section may permeate the inner layer.

  The thermal lamination method includes laminating a co-pressing film composed of the acid-modified polyolefin layer 9 and the heat-adhesive resin layer 8 on the metal foil 7 by the thermal lamination method, and the molten acid-modified polyolefin layer 9 to the metal foil 7. There is a sandwich lamination method in which the film is sandwiched and laminated between the heat-adhesive resin layer 8 and each method is a lamination method that is superior in content resistance and durability as compared with the dry lamination method.

  Specifically, the thermal lamination method is a conversion treatment surface of a metal foil layer such as aluminum obtained by chemical conversion treatment on the surface of the acid modification polyolefin layer 8 of the coextruded film comprising the acid modification polyolefin layer 9 and the heat adhesive resin layer 8. Is a method of laminating and heat laminating.

  The sandwich lamination method is a method in which the acid-modified polyolefin layer 9 is extruded as an adhesive resin on the chemical conversion surface of the metal foil 7 and adhered to the heat-adhesive resin layer 8. Here, when the acid-modified polyolefin layer 9 is extrusion laminated, the resulting laminate is heated to the softening point or higher of the acid-modified polyolefin (post-heating), or in the extrusion process of the acid-modified polyolefin, the aluminum surface is By heating above the softening point of the acid-modified olefin (preheating), a laminate having an adhesive strength that can withstand content resistance and moldability can be obtained as an exterior body.

  As this heating method, there are methods such as a hot roll contact method, a hot air method, a near or far infrared ray, etc., but in the present invention, any heating method may be used, and as described above, the adhesive resin exceeds its softening point temperature. It only needs to be heated.

  The present invention is not limited to the above-described embodiments, and various modifications are possible. Embodiments obtained by appropriately combining technical means disclosed in different embodiments are also included in the present invention. Included in the technical scope. For example, an intermediate layer made of a biaxially stretched film such as polyimide or polyethylene terephthalate may be provided between the metal foil 7 and the thermal adhesive resin layer 8. The intermediate layer can improve the strength as a packaging material and improve and stabilize the barrier property.

  In addition, by using a high melting point type having a melting point of 140 to 180 ° C. for the intermediate layer, even when a high-temperature content is stored inside the outer package, the intermediate layer does not melt, The inner sealing performance can be further ensured.

Further, a polypropylene layer melt-extruded on the surface of the heat-adhesive resin layer 8 can be additionally processed. By additionally processing the melt-extruded polypropylene layer, the heat seal temperature can be lowered while ensuring a predetermined seal strength. This is presumably because the melt-extruded polypropylene layer has a lower melting point and higher fluidity than other polypropylene layers that are not melt-extruded and constitute the heat-adhesive resin layer 8.
[Example 1]

  Hereinafter, the operation and effect of the present invention will be specifically described with reference to examples. First, a stretched nylon film (thickness 25 μm) is bonded to one surface of aluminum (thickness 40 μm) by a dry laminating method via a two-component curable polyurethane adhesive, and an acid-modified polypropylene ( 15 μm thick) was melt extruded and an unstretched polypropylene film (thickness 30 μm) was laminated to obtain a packaging material of Comparative Example 1.

Next, a stretched nylon film (thickness 25 μm) is bonded to one surface of aluminum (thickness 40 μm) by a dry laminating method via a two-component curable polyurethane adhesive, and a fluorine-based polyol is adhered to the other surface. An adhesive solution in which 1.1 equivalents of each of IPDI nurate and IPDI were added to 1 equivalent of a hydroxyl group (—OH group) of a fluorine-based polyol was applied to the adhesive layer to 3.0 g / m ² after drying. -It dried and the 30-micrometer-thick unstretched polypropylene film was heat-compressed to the said adhesive layer surface, and the packaging material of the comparative example 2 was obtained. (Dry lamination method)

  Next, a stretched nylon film (thickness: 25 μm) is bonded to one surface of aluminum (thickness: 40 μm) by a dry laminating method via a two-component curable polyurethane adhesive, and acid-modified polypropylene is bonded to the other surface. This is made by melting and extruding an acid-modified polypropylene (thickness 15 μm) in which 10% by weight of a propylene-based elastomer resin (trade name: Notio, manufactured by Mitsui Chemicals) is mixed with the resin and laminating an unstretched polypropylene film (thickness 30 μm). The packaging material of the invention 1 was obtained.

  Next, a stretched nylon film (thickness: 25 μm) is bonded to one surface of aluminum (thickness: 40 μm) by a dry laminating method via a two-component curable polyurethane adhesive, and acid-modified polypropylene is bonded to the other surface. This is made by melting and extruding acid-modified polypropylene (thickness 15 μm) in which 20% by weight of propylene-based elastomer resin (trade name: Notio, manufactured by Mitsui Chemicals) is mixed with the resin and laminating an unstretched polypropylene film (thickness 30 μm). The packaging material of the invention 2 was obtained.

  Next, a stretched nylon film (thickness: 25 μm) is bonded to one surface of aluminum (thickness: 40 μm) by a dry laminating method via a two-component curable polyurethane adhesive, and acid-modified polypropylene is bonded to the other surface. This is made by melting and extruding an acid-modified polypropylene (thickness 15 μm) in which 30% by weight of a propylene-based elastomer resin (trade name: Notio, manufactured by Mitsui Chemicals) is mixed with the resin and laminating an unstretched polypropylene film (thickness 30 μm). The packaging material of the invention 3 was obtained.

Next, a stretched nylon film (thickness 25 μm) is bonded to one surface of aluminum (thickness 40 μm) by a dry laminating method via a two-component curable polyurethane adhesive, and a fluorine-based polyol is adhered to the other surface. The adhesive solution in which 1.1 equivalent each of IPDI nurate and IPDI was added to 1 equivalent of the hydroxyl group (—OH group) of the fluorine-based polyol was applied to the adhesive layer after drying to 3.0 g / μm. The packaging of the present invention 4 is dried and heated and compressed on the adhesive layer surface with an unstretched polypropylene film (thickness 30 μm) in which 20% by weight of a propylene-based elastomer resin (trade name: Notio, manufactured by Mitsui Chemicals) is mixed with the polypropylene resin. The material was obtained. (Dry lamination method)

  Next, a stretched nylon film (thickness: 25 μm) is bonded to one surface of aluminum (thickness: 40 μm) by a dry laminating method via a two-component curable polyurethane adhesive, and acid-modified polypropylene is bonded to the other surface. An acid-modified polypropylene (thickness 15 μm) in which 20% by weight of a propylene-based elastomer resin (trade name: Notio, manufactured by Mitsui Chemicals) is mixed with the resin is melt-extruded and a propylene-based elastomer resin (trade name: Notio, An unstretched polypropylene film (thickness 30 μm) mixed with 20% by weight of Mitsui Chemicals was laminated to obtain a packaging material of the present invention 5.

  Next, the packaging materials of Comparative Examples 1 and 2 and Inventions 1 to 4 are cut into 60 mm (MD direction) × 60 mm (TD direction) strips, and a concave tray having a depth of 6.0 mm is formed by press molding. It was created. FIG. 4 is a perspective view showing an apparatus for measuring an insulation evaluation method, and a test solution (composed of ethanolamine, glycol ether, phosphate, nonionic surfactant, water) is applied to the concave molding portion. Put 3g, set the positive electrode terminal in the test solution and set the tip of the negative electrode terminal to reach the aluminum foil of the exterior body, and apply the voltage 25V for 10 seconds with an insulation resistance measuring instrument (manufactured by HIOKI: Model No. 3154). Was measured. The results are shown in the table of FIG.

  As is apparent from the table of FIG. 5, the packaging materials of Comparative Examples 1 and 2 were pressed with aluminum in the present example, while aluminum was energized, whereas at least one of acid-modified polypropylene or unstretched polypropylene film was propylene. In the packaging materials of the present invention 1 to 4 in which a base elastomer resin (trade name: Notio, manufactured by Mitsui Chemicals) was mixed, no energization of aluminum was observed. Thus, it was found that the unstretched polypropylene film or the acid-modified polypropylene to which the propylene-based elastomer resin (trade name: Notio, manufactured by Mitsui Chemicals) was added improved toughness, and no cracks were generated in press molding.

  Moreover, when the packaging material after press molding was observed visually, the packaging materials of the present invention 1 to 3 could confirm that the unstretched polypropylene film was whitened, but in the present inventions 4 and 5, whitening was achieved. Could not be confirmed. In Comparative Example 1, whitening was confirmed in both the unstretched polypropylene film and the acid-modified polypropylene, and in Comparative Example 2, whitening was confirmed only in the unstretched polypropylene film.

From these facts, it was found that whitening was easily caused by press molding in a layer to which a propylene-based elastomer resin (trade name: Notio, manufactured by Mitsui Chemicals) was not added.
[Example 2]

  Next, the packaging materials of Comparative Examples 1 and 2 and Inventions 1 to 4 prepared in Example 1 were cut into strips of 60 mm (MD direction) × 60 mm (TD direction), as shown in FIG. First, the strip is folded in half and fixed in the MD direction with the Manriki 10 (see FIG. 6A), then one side is folded back 90 ° (see FIG. 6B), and then folded back along the holding jig 11. (See FIG. 6 (c)). Next, after removing the Manriki 10 and heat-sealing the part sandwiched between the Manriki 10 (see FIG. 6D), the heat-sealed part is fixed again with the Manriki 10 and folded back along the holding jig 11. Return the original part to its original state (see FIG. 6 (e)), turn both sides of the strip into 90 ° at the time of sealing (see FIG. 6 (f)), heat-seal both sides, and pouch-shaped packaging material (See FIG. 6G). Next, 3 g of a test solution (composed of ethanolamine, glycol ether, phosphate, nonionic surfactant, water) is placed in the pouch, the positive electrode terminal is used as the test solution, and the tip of the negative electrode terminal is the outer package. It set so that it might reach aluminum foil, voltage 25V was applied for 10 seconds with the insulation resistance measuring device (the product made from HIOKI, model number 3154), and the insulation resistance value was measured, and the result is shown in the table | surface of FIG.

  As is clear from the table of FIG. 7, when a crease is made in the TD direction perpendicular to the orientation direction (MD direction) of the heat seal resin, a propylene-based elastomer resin (trade name: Notio, manufactured by Mitsui Chemicals) is mixed. The packaging materials of the present invention 1 to 4 were not energized with aluminum, whereas the propylene elastomer resin (trade name: Notio, manufactured by Mitsui Chemicals) was not mixed. The aluminum was confirmed to be energized. As a result, the unstretched polypropylene film or acid-modified polypropylene to which a propylene-based elastomer resin (trade name: Notio, manufactured by Mitsui Chemicals) is added has improved toughness, and even after the heat seal, the seal portion is bent in the TD direction. It was found that no cracks occurred.

DESCRIPTION OF SYMBOLS 1 Container 5 Packaging material 6 Base material layer 7 Metal foil 7a Chemical conversion treatment layer (metal foil layer surface)
8 Thermal adhesive resin layer 9 Acid modified polyolefin layer 10 Manriki 11 Holding jig

Claims (3)

In a packaging material in which a base material layer, a metal foil layer, an adhesive layer, and a thermal adhesive resin layer are sequentially laminated,
At least 1 layer of the said adhesive bond layer or the said heat bondable resin layer contains the polyolefin resin layer to which the olefin elastomer resin was added, The packaging material characterized by the above-mentioned.   The packaging material according to claim 1, wherein the adhesive layer is made of an acid-modified polyolefin resin.   The packaging material according to claim 2, wherein the adhesive layer is made of acid-modified polypropylene, the thermal adhesive resin layer is made of a propylene resin, and the olefin elastomer resin is a propylene elastomer resin.

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