JP6832695B2 - Laminate - Google Patents

Description

The present invention relates to a laminate.

As a material constituting a container for storing chemicals, cosmetics, foods, toothpaste, etc., for example, a plurality of films having various functions including barrier properties in order to protect the contents from environmental factors such as moisture and oxygen. Laminates are known.

As the above-mentioned laminate, for example, a laminate in which a surface resin layer and a sealant layer having a heat-sealing function are laminated on both sides of a barrier layer (typically an aluminum layer) for protecting the contents is known. ing. As a container using such a laminated body, for example, a tube container is known. In the tube container, for example, a shoulder portion having a screw for sealing is formed on a body portion obtained by sealing the above laminate into a tubular shape, a cap is screwed into the shoulder portion, and then an open end of the body portion buttock portion is formed. It can be manufactured by the step of filling the contents from the slab and end-sealing the open end.

As prior art for a laminate using an aluminum layer as a barrier layer for protecting the contents, for example, the techniques of Patent Documents 1 to 4 have been proposed.

Example 1 of Patent Document 1 includes a surface resin layer, an aluminum layer, and a linear low-density polyethylene (LLDPE) having a thickness of 30.5 μm, which is a sealant layer, and ethylene is provided between the aluminum layer and the sealant layer. A laminate bonded with an acrylic acid copolymer (EAA) is disclosed. The laminate of Patent Document 1 is expected to be applied to toothpaste and the like.

Example 1 of Patent Document 2 includes a surface resin layer, an aluminum layer, and an LLDPE which is a sealant layer, respectively, and the aluminum layer and the sealant layer are adhered to each other by an ethylene-methacrylic acid copolymer (EMAA). The laminated body for the tube is disclosed.

In Example 1 of Patent Document 3, polyethylene terephthalate (PET) layers are laminated on both sides of an aluminum layer, and a two-component curable urethane system is used between one of the PET layers and an ionomer layer having a thickness of 40 μm. A packaging material bonded with a special anchor coating agent is disclosed.

In Example 1 of Patent Document 4, an LLDPE layer is laminated on a printed layer formed on one side of a PET substrate, an aluminum foil is laminated on the LLDPE layer via EMAA, and then the aluminum foil is laminated. A tube container formed of a laminated body in which an LLDPE layer is further laminated on top via EMAA and then an LLDPE layer is laminated on the other surface of the PET base material via a polyethylene resin is disclosed.

Japanese Unexamined Patent Publication No. 3-647 Japanese Unexamined Patent Publication No. 2004-167975 JP-A-11-254595 Japanese Unexamined Patent Publication No. 2010-235177

The container formed from the above-mentioned known laminate exhibits excellent sealing property and filling storage stability in the weakly acidic to alkaline region. However, in the strongly acidic region, the content may permeate the sealant layer and stay between the sealant layer and the aluminum layer, weakening the laminated structure on the content side of the aluminum layer.

In particular, in the field of hair dyeing, a new product category called hair color treatment (hair manicure) products has been born and is expanding in addition to the conventional mainstream hair color products. The pH of hair color treatments varies greatly depending on the type, and there are also strongly acidic products with a pH of 4.0 or less.

The above hair color treatment may further contain a branched higher alcohol in order to express the functions of an emollient agent, an emulsifier, a quality improver and the like. When a container formed from a known laminate is filled with a content containing a branched higher alcohol, the same as in the case of the above-mentioned strongly acidic content, even when the acidity of the content is not so high. Penetration and retention may occur, resulting in weakening of the laminated structure.

Interestingly, the permeation and retention of the higher alcohol is a phenomenon peculiar to the case where the long-chain alkyl group of the higher alcohol has a branched structure. Such a problem does not occur in the case of a content containing only an alcohol having a linear alkyl group as a higher alcohol.

The present invention has been made in an attempt to solve the above problems. Therefore, an object of the present invention is
Even when filled with a content selected from a strongly acidic content and a content containing a branched higher alcohol represented by a hair color treatment, the laminated structure on the content side rather than the barrier layer is weakened. It is to provide a packaging material that provides a container that does not.

The present invention achieves the above object by means summarized below.

[1] It has an outer layer, a first adhesive layer, an aluminum layer, a second adhesive layer, a third adhesive layer, and a sealant layer in this order.
The second adhesive layer contains an ethylene-methacrylic acid copolymer and contains
The third adhesive layer contains an ethylene-acrylic acid copolymer.
Laminated body.

[2] The laminate according to [1], wherein the sealant layer contains linear low-density polyethylene.

[3] A container containing the molded product of the laminate according to [1] or [2].

[4] The container according to [3], which is used for filling the contents selected from hair care products, cosmetics, and pharmaceuticals.

[5] The container according to [4], wherein the content is selected from a content having a pH of 2.0 or more and 4.0 or less, and a content containing a branched higher alcohol.

[6] In the container described in [3],
Filled with content selected from hair care products, cosmetics, and pharmaceuticals,
Filling container.

[7] The filling container according to [6], wherein the content is selected from a content having a pH of 2.0 or more and 4.0 or less and a content containing a branched higher alcohol.

Even when the laminate of the present invention is filled with a strongly acidic content or a content containing a branched higher alcohol, the laminated structure on the content side of the aluminum layer is not weakened. Therefore, the laminate of the present invention can be suitably used for producing a container filled with a content selected from a content having a wide pH range containing strong acid and a content containing a branched higher alcohol. ..

FIG. 1 is a cross-sectional view for explaining the structure of the laminated body of the present invention.

<Laminated body>
The laminate of the present invention has an outer layer, a first adhesive layer, an aluminum layer, a second adhesive layer, a third adhesive layer, and a sealant layer in this order.
The second adhesive layer contains an ethylene-methacrylic acid copolymer and contains
The third adhesive layer contains an ethylene-acrylic acid copolymer.

The laminate of the present invention exhibits high resistance to both strongly acidic contents and contents containing branched higher alcohols by adopting the above-mentioned structure. It is not clear why the laminate of the present invention exerts such an effect. However, the present inventors infer as follows. However, the present invention is not bound by any particular theory.

The third adhesive layer in the laminate of the present invention contains an ethylene-acrylic acid copolymer (EAA). Unlike the ethylene-methacrylic acid copolymer (EMAA) adhesive resin in known laminates, EAA does not have a methyl group that directly binds to the polymer chain, so its properties are closer to those of polyethylene. Therefore, it is considered that EAA preferably has an excellent affinity with the sealant layer containing LLDPE. Therefore, a strong affinity acts between the two layers, and it is presumed that this does not impair the laminate strength or the like even under acidic conditions. In fact, a container manufactured from a laminate using a third adhesive layer containing EAA has a weaker laminated structure on the content side than the aluminum layer, even when the strongly acidic content is stored. High heat seal strength and high laminate strength are maintained for a long period of time.

When the content contains a branched higher alcohol, it is inferred as follows.

Since LLDPE preferably contained in the sealant layer has an alkyl group directly bonded to a polymer chain composed of an ethylene chain, it has a structure similar to that of a branched alkyl group of a branched higher alcohol. Therefore, the branched higher alcohol has a high affinity with the sealant layer. Therefore, when a container formed from a known laminate is filled with a content containing a branched higher alcohol, the content permeates the sealant layer and reaches the adhesive layer, attacking the hydrogen bond between the aluminum layer / the adhesive layer. It is considered that the laminated structure is weakened by dissociating the hydrogen bonds.

On the other hand, in the laminate of the present invention, the second adhesive layer contains EMAA having a methyl group in the polymer chain. It is considered that the electron donating property of the methyl group in the second adhesive layer increases the electron density of the carbonyl portion involved in the hydrogen bond between the aluminum layer / the adhesive layer, and the bonding force of the hydrogen bond is strengthened. Then, even if the contents permeate the sealant layer and reach the adhesive layer and attack the hydrogen bond between the aluminum layer / the adhesive layer, the divergence of the strengthened hydrogen bond is not reached, and therefore, the EMA-containing first. It is presumed that the laminate of the present invention provided with the adhesive layer of 2 has a high degree of resistance to branched higher alcohol.

Further, since the EMAA in the second adhesive layer and the EAA in the third adhesive layer have similar structures, the adhesive strength between the two layers is high. Therefore, the interlayer adhesive strength of the laminate of the present invention is as a whole. Will be extremely high.

FIG. 1 shows a cross-sectional view for explaining a typical structure of the laminate of the present invention. The laminate of FIG. 1 has an outer layer 1, a first adhesive layer 2, an aluminum layer 3, a second adhesive layer 4, a third adhesive layer 5, and a sealant layer 6 in this order.
The second adhesive layer 4 contains an ethylene-methacrylic acid copolymer,
The third adhesive layer 5 contains an ethylene-acrylic acid copolymer.

Hereinafter, the laminate of the present invention will be described in detail with a focus on preferred embodiments thereof.

[Outer layer]
The outer layer in the laminate of this embodiment can be made of, for example, a resin. The outer layer may be a single layer composed of one resin layer, or may be a laminate composed of a plurality of resin layers. Printing may be applied to one or more of the layers constituting the outer layer.

The outer layer is present in the laminated body in order to impart the strength required for the laminated body, the waist required at the time of processing, and the like to the laminated body of the present embodiment. As the material constituting the outer layer, for example, a polyester-based resin film, a polyamide-based resin film, a polyolefin-based resin film, or the like may be used.

Examples of the polyester-based resin film include a film made of polyethylene terephthalate and the like. Examples of the polyamide-based resin film include films made of various types of nylon and the like. Examples of the polyolefin-based resin film include a film made of a polyethylene-based resin, a polypropylene-based resin, a cyclic polyolefin resin, and the like. These films may be biaxially stretched in order to further improve the heat resistance and impact resistance of the obtained laminate.

The outer layer in the present embodiment may be a single-layer or multi-layer film composed of a polyester-based resin film, a polyamide-based resin film, a polyolefin-based resin film, or the like, or a film based on these films as a base material. A laminated film having a surface resin layer made of a resin having a heat-sealing property may be used on the material, or a white film or the like may be used as a part of the outer layer.

When a laminated film having the above-mentioned surface resin layer on a base material is used as an outer layer and the surface resin layer is used as the outermost layer, the surface resin layer is a sealant when the laminated body is molded into a container shape. It is preferable in that it can be fused with the layer to form a tubular body.

Examples of the heat-sealing resin include low-density polyethylene (LDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), linear low-density polytylene (LLDPE), polypropylene (PP), and ethylene-acetate. Vinyl copolymer (EVA), ionomer resin, ethylene-acrylic acid copolymer (EAA), ethylene-acrylic acid ester copolymer (eg ethylene-ethyl acrylate copolymer), ethylene-methacrylic acid copolymer (eg) EMAA), an ethylene resin selected from an ethylene-methacrylate ester copolymer (for example, an ethylene-ethyl methacrylate copolymer) and the like can be mentioned.

When a laminated film having a surface resin layer made of a heat-sealing resin is used as the outer layer, the thickness of the base material may be, for example, 5 μm or more, 10 μm or more, or 12 μm or more, for example. , 100 μm or less, 50 μm or less, 30 μm or less, or 25 μm or less.

When a layer made of an ethylene resin is used as the surface resin layer in the laminated film, the thickness of the surface resin layer is, for example, 20 μm or more from the viewpoint of improving processability, surface slipperiness, heat sealability, and the like. It can be 30 μm or more, or 40 μm or more, for example, 100 μm or less, 80 μm or less, or 60 μm or less.

The thickness of the outer layer (in the case where the outer layer is composed of a plurality of layers, the total thickness of these layers) in the laminated body of the present embodiment can be, for example, 5 μm or more, 10 μm or more, or 15 μm or more, for example, 500 μm. Hereinafter, it can be 300 μm or less, or 200 μm or less.

As the outer layer, those supplied as a film may be used.

[First adhesive layer]
The first adhesive layer in the laminated body of the present embodiment is a layer for joining the above-mentioned outer layer and the later-described aluminum layer. The first adhesive layer can be appropriately selected by those skilled in the art depending on the method for producing the laminate. For example, as a method of joining both layers when the outer layer and the aluminum layer are formed in a film shape in advance, for example,
Dry laminating method using a dry laminating adhesive;
Laminating method using other adhesives;
Examples thereof include a sand laminating method in which an adhesive resin is extruded between an outer layer and an aluminum layer by a melt extrusion method.

As an example of the case where the outer layer is formed by the melt extrusion method, for example, a method of appropriately forming the adhesive resin and the outer layer on the aluminum layer by the melt extrusion method can be mentioned.

Examples of the dry laminating adhesive include urethane-based adhesives, polyester-based adhesives, titanate-based adhesives, imine-based adhesives, butadiene-based adhesives, and olefin-based adhesives. Of these, thermosetting adhesives are preferable, and urethane-based adhesives are particularly preferable.

Examples of the other adhesives include a two-component curable polyurethane adhesive, a polyvinyl acetate adhesive, a polyacrylic acid ester adhesive, a cyanoacrylate adhesive, an ethylene copolymer adhesive, and the like. Can be done.

Examples of the adhesive resin suitable for forming by the above-mentioned melt extrusion method include ionomer resins and olefin-based (co) polymers, and preferred examples thereof include, for example.
Low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), linear low density polytilene (LLDPE), polypropylene (PP);
Ethylene-vinyl acetate copolymer;
Ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), ethylene-ethylacrylate copolymer (EEA), ethylene-methylacrylate copolymer (EMA), ethylene-methacrylate copolymer Ethylene- (meth) acrylic monomer copolymer such as (EMAA);
And so on.

When the first adhesive layer is formed by the melt extrusion method, the thickness of the first adhesive layer can be, for example, 5 μm or more, 10 μm or more, or 20 μm or more, and 100 μm or less, 75 μm or less, or 50 μm or less. Can be.

[Aluminum layer]
The aluminum layer in the laminate of the present embodiment is used to improve barrier properties such as light-shielding property, oxygen-blocking property, water vapor-blocking property, and aroma-retaining property in the laminated body in order to protect the contents.

The thickness of the aluminum layer can be appropriately set from the viewpoints of exhibiting sufficient barrier properties, developing a high-class metallic luster, making it more difficult to wrinkle, and providing good handling when used as a container. For example, it can be 5 μm or more, 6 μm or more, 8 μm or more, or 10 μm or more, and can be 50 μm or less, 40 μm or less, 30 μm or less, or 25 μm or less.

As the aluminum layer, a commercially available aluminum foil having a desired thickness may be appropriately selected and used.

[Second adhesive layer]
The second adhesive layer in the laminate of the present embodiment is a layer for joining the above-mentioned aluminum layer and the later-described sealant layer together with the later-described third adhesive layer.

The second adhesive layer in the laminate of this embodiment contains an ethylene-methacrylic acid copolymer (EMAA). The second adhesive layer in the laminated body of the present embodiment may be a layer composed of only EMAA, or may contain another resin together with EMAA. Examples of other resins used here include EAA, ethylene-methylmethacrylate copolymer (EMMA) and the like. The second adhesive layer may contain EMAA in an amount of 50% by weight or more, 60% by weight or more, 70% by weight or more, 80% by weight or more, 90% by weight or more, or 95% by weight or more, and is a layer consisting only of EMAA. It may be.

The thickness of the second adhesive layer in the laminate of the present embodiment can be, for example, 20 μm or more, 30 μm or more, or 50 μm or more, and can be, for example, 150 μm or less, 100 μm or less, or 75 μm or less.

[Third adhesive layer]
The third adhesive layer in the laminate of the present embodiment is a layer for joining the above-mentioned aluminum layer and the later-described sealant layer together with the above-mentioned second adhesive layer.

The third adhesive layer in the laminate of this embodiment contains an ethylene-acrylic acid copolymer (EAA). The third adhesive layer in the laminate of the present embodiment may be a layer composed of EAA alone, or may contain other resins together with EAA. Examples of other resins used here include EMAA and EMMA. The third adhesive layer may contain 50% by weight or more, 60% by weight or more, 70% by weight or more, 80% by weight or more, 90% by weight or more, or 95% by weight or more of EAA, and is a layer consisting only of EAA. It may be.

The thickness of the third adhesive layer in the laminate of the present embodiment can be, for example, 5 μm or more, 10 μm or more, or 15 μm or more, and can be, for example, 150 μm or less, 100 μm or less, or 75 μm or less.

[Sealant layer]
The sealant layer in the laminate of the present embodiment preferably has heat-sealing properties. This sealant layer is heat-sealed with the surface resin layer in the outer layer to form, for example, a tubular body constituting a body portion in a tube container, and / or heat-seal the opposing sealant layers of the tubular body. By doing so, for example, it has a function of sealing the tail portion of the tube container.

Examples of the resin constituting the sealant layer include polypropylene (PP), ethylene-vinyl acetate copolymer (EVA), ionomer resin, ethylene-acrylic acid copolymer (EAA), and ethylene-methacrylic acid copolymer (EMAA). ), Polyethylene and the like. Polyethylene is preferable, and specifically, for example, HDPE, MDPE, LDPE, LLDPE and the like may be used. When the content is a semi-fluid substance such as cream, LLDPE is preferable from the viewpoint of imparting good low-temperature heat-sealing property, contaminant-sealing property, and processability.

The sealant layer may be a single layer composed of one resin layer, or may be a laminate composed of a plurality of resin layers. When the sealant layer is a laminate composed of a plurality of resin layers, the resins constituting the respective layers may be the same or different from each other.

The sealant layer may be formed by an appropriate film forming method such as a melt extrusion method or a coextrusion method using a resin supplied in the form of pellets or the like, or the resin supplied as a film may be used as it is. You may. However, in order to form a laminated body that can form a stronger bond with the above-mentioned third adhesive layer and the laminate strength and the like are not easily impaired even under acidic conditions, this sealant layer is formed by a melt extrusion method. It is preferable to form a film.

The thickness of the sealant layer in the laminate of the present embodiment may be, for example, 20 μm or more, 30 μm or more, 40 μm or more, or 50 μm or more, and may be 150 μm or less, 100 μm or less, or 90 μm or less.

<Manufacturing method of laminated body>
The laminate of the present embodiment can be produced by a known method other than using each of the above layers, or by appropriately modifying it by a person skilled in the art.

In producing the laminate of the present embodiment, the above-mentioned outer layer, first adhesive layer, aluminum layer, second adhesive layer, third adhesive layer, and sealant layer are separately prepared, and these are prepared separately. It may be a method of pasting together; or
The aluminum layer and the unit resin layers constituting the other layers are laminated in any order, and as a result, the outer layer, the first adhesive layer, the aluminum layer, the second adhesive layer, and the third adhesive layer, And a laminate in which the sealant layers are laminated in this order may be obtained.

The second adhesive layer and the third adhesive layer in the laminate of the present embodiment can be formed by a film forming method such as a melt extrusion method using a resin supplied in the form of pellets or the like, respectively. preferable.

It is also possible to form the second adhesive layer and the third adhesive layer; the third adhesive layer and the sealant layer; or the second adhesive layer, the third adhesive layer, and the sealant layer by the coextrusion method. This is a preferred embodiment in the form.

When the thickness of the sealant layer in the laminate of the present embodiment is 70 μm or more, the desired heat seal strength is stably exhibited even if the processing temperature at the time of forming the sealant layer by the melt extrusion method fluctuates slightly. Therefore, it may be preferable.

<Container and its manufacturing method>
A container can be manufactured by using the laminate of the present embodiment described above. The container of the present embodiment includes a molded body of a laminated body.

The container containing the molded body of the laminated body of the present embodiment can be used by filling, for example, hair care products, cosmetics, pharmaceuticals, etc. as the contents. Specific examples of hair care products include, for example, hair color treatments; specific examples of cosmetics include, for example, facial cleansers, lotions, lotions, etc .; specific examples of pharmaceuticals include, for example, creams, ointments, etc. Liquids, gels, lotions, etc .; can be mentioned respectively.

When the above-mentioned contents are selected from the contents having a pH of 2.0 or more and 4.0 or less and the contents containing a branched higher alcohol, the expected effect of the present invention is maximized. And preferred.

The branched higher alcohol is preferably contained in recent hair color treatments in order to exhibit the functions of emollients, emulsifiers, quality improvers and the like. Examples of the branched higher alcohol include alcohols having a branched alkyl group having 12 or more carbon atoms. The number of carbon atoms of the branched alkyl group in the branched higher alcohol may be 14 or more or 16 or more, and may be 30 or less, 28 or less, 26 or less, 24 or less, 22 or less, or 20 or less. Specific examples of the branched higher alcohol include hexyldecanol and octyldodecanol.

The container of the present embodiment typically has the component name of the content printed on the outer surface of the container or labeled on the outer surface of the container with the component name of the content. used.

Hereinafter, a method for manufacturing a container will be described by taking the case of manufacturing a tube container as an example.

The tube container using the laminate of the present embodiment is, for example, a step of cutting the laminate to an appropriate size, sealing the side portions to form a tubular body portion, and forming a shoulder portion and a lip portion. Can be manufactured by. By attaching an appropriate cap to this container, filling it with the contents, and sealing the buttock, it can be used as a tube-type closed container. The order of implementation of the above steps can be changed arbitrarily.

For the seals of the side portion and the tail portion, for example, a heat seal, hot air, and an ultrasonic seal can be used, and a seal by a high frequency continuous oscillation method can be used, respectively.

In the following Examples and Comparative Examples, the following commercially available products were used as the resins in each layer. For the material with the notation "f" following the capital letter of the alphabet, the material supplied in the form of a film is used as it is, and for the material without the notation "f", the raw material supplied as pellets is melt-extruded (back laminating method or It was formed in layers by a sandwich lamination method. “ALf” indicates an aluminum foil, and a commercially available product manufactured by UACJ Corporation having a predetermined thickness was used as it was. In the following description, the number immediately after the material symbol is the thickness in μm.

PETf: Polyethylene terephthalate film (manufactured by Toyobo Co., Ltd., product name "E5100", thickness 12 μm and 25 μm, double-sided corona discharge treatment)
Milky white HDPEf: Milky white high-density polyethylene film (manufactured by Aicello Corporation, product name "FA-550 white", thickness 60 μm)
LLDPE: Linear low density polyethylene (manufactured by Prime Polymer Co., Ltd., product name "SP15101D", pellets)
LDPE: Low density polyethylene (manufactured by Asahi Kasei Polychemicals Co., Ltd., product name "M1880E", pellets)
EAA: Ethylene-acrylic acid copolymer (manufactured by Japan Polyethylene Corporation, product name "A201M", pellets)
EMAA: Ethylene-methacrylic acid copolymer (manufactured by Mitsui / DuPont Polychemical Co., Ltd., product name "N0908C", pellets)

<Manufacturing of laminate>
[Example 1]
An anchor coating agent was applied on the surface of PETf25 as an outer layer. ALf20 is prepared as an aluminum layer, and sand lamination is performed while extruding EMAA as a first adhesive layer between the PETf25 and the anchor coating agent-coated surface, and PETf12, EMAA30 (first adhesive layer), and ALf20 are formed. A three-layered laminated body a laminated in this order was obtained. An EMAA layer (EMAA55) having a thickness of 55 μm was formed as a second adhesive layer on the surface of the laminate a on the ALf side by an extrusion method to obtain a four-layered laminate b. Next, an EAA layer (EAA50) having a thickness of 50 μm was formed as a third adhesive layer on the surface of the laminate b on the EMAA55 side by an extrusion method to obtain a five-layered laminate c.

Subsequently, an LDPE layer (LDPE50) having a thickness of 50 μm as a sealant layer is formed on the surface of the laminate c on the EAA50 side by an extrusion method to obtain a laminate of Example 1 having the following layer structure. It was.
PETf25 / EMAA30 / ALf20 / EMAA55 / EAA50 / LLDPE50 (6 layers)

[Example 2]
The laminate of Example 2 having the following layer structure was obtained in the same manner as in Example 1 except that the thickness of the EAA layer as the third adhesive layer was 30 μm and the thickness of the LLDPE as the sealant layer was 70 μm. It was.
PETf25 / EMAA30 / ALf20 / EMAA55 / EAA30 / LLDPE70 (6 layers)

[Example 3]
The laminate of Example 3 having the same layer structure as that of Example 2 was obtained in the same manner as in Example 2 except that EAA30 as the third adhesive layer and LLDPE70 as the sealant layer were formed by the coextrusion method. Obtained.
PETf25 / EMAA30 / ALf20 / EMAA55 / EAA30 / LLDPE70 (6 layers)

[Example 4]
A laminate of Example 4 having the following layer structure was obtained in the same manner as in Example 3 except that the thickness of the EAA layer as the third adhesive layer was 15 μm.
PETf25 / EMAA30 / ALf20 / EMAA55 / EAA15 / LLDPE70 (6 layers)

[Comparative Example 1]
An anchor coating agent was applied on the surface of PETf25. ALf20 is prepared, sand-laminated while extruding EMAA between the PETf25 and the anchor coating agent-coated surface, and PETf25, EMAA30 (first adhesive layer), and ALf20 are laminated in this order to form a three-layer structure. I got a body a. An EMAA layer (second adhesive layer, EMAA55) having a thickness of 55 μm was formed on the surface of the laminate a on the ALf20 side by an extrusion method to obtain a laminate b. Next, after applying an anchor coating agent on the PETf25 side surface of the laminate b, sand laminating is performed while extruding LDPE between the laminate b and the milky white HDPEf60, and the milky white HDPEf60, LDPE20, PETf25, EMAA30, ALf20, and EMAA55 are used. A 6-layer laminated body c laminated in order was obtained.

Subsequently, an LDPE layer (LDPE50) having a thickness of 50 μm is formed on the surface of the laminate c on the milky white HDPEf60 side to form a laminate d, and then the laminate d is extruded onto the surface of the laminate d on the EMAA55 side. By forming an LLDPE layer (sealant layer, LLDPE45) having a thickness of 45 μm by the method, a laminate of Comparative Example 1 was obtained. A third adhesive layer is not formed in this laminated body.

The layer structure of the laminated body of Comparative Example 1 is as follows.
LDPE50 / milky white HDPEf60 / LDPE20 / PETf25 / EMAA30 / ALf20 / EMAA55 / LLDPE45 (8-layer configuration)

[Comparative Example 2]
ALf25 was laminated on PETf25 via a two-component reaction-curing adhesive (first adhesive layer), and this was used as a laminate a. An EAA layer (third adhesive layer, EAA30) having a thickness of 30 μm was formed on the surface of the laminate a on the ALf25 side by an extrusion method to obtain a laminate b. Then, an LLDPE layer (sealant layer, LLDPE70) having a thickness of 70 μm was formed on the surface of the laminate b on the EAA30 side by an extrusion method at a temperature below the die: 300 ° C. to obtain the laminate of Comparative Example 2. .. A second adhesive layer is not formed in this laminated body.

The layer structure of the laminated body of Comparative Example 2 is as follows.
PETf12 / 2 liquid reaction curing adhesive / ALf25 / EAA30 / LLDPE70 (5-layer structure)

The layer structures of the laminates of Examples 1 to 4 and Comparative Examples 1 and 2 obtained above are summarized in Table 1 below.

<Evaluation of laminated body>
Using the laminates obtained in the above Examples and Comparative Examples, a plurality of three-way seal bags having an inner size of MD100 mm × TD50 mm were prepared with the sealant layer side inside, and various hair colors shown in Table 1 were prepared for each. After filling 25 g of the treatment, the opening side was sealed to prepare a hair color treatment filling bag. This filling bag was stored at 50 ° C. for 1 month. The peel strength between each layer before and after storage was measured by the following method.

A plurality of strip-shaped test pieces having a length of 100 mm and a width of 15 mm were cut out from the filling bag after storage for one month so that the MD direction was the long side direction. The aluminum layer / second adhesive layer, the second adhesive layer / third adhesive layer, or the third adhesive layer / sealant layer inside the aluminum layer of these test pieces is slightly peeled off and sandwiched between chucks. Using a strograph "VES10" manufactured by Toyo Seiki Seisakusho Co., Ltd., the T-type peel strength was measured at a gripping movement speed of 300 mm / min (JIS K6854). The evaluation results are shown in Table 2.

The abbreviations for hair color treatments in Table 2 represent the following products, respectively.
A: Kenlux (manufactured by Intercosme Co., Ltd.)
B: Teiala (manufactured by Shiseido Co., Ltd.)
C: Cover Gray (manufactured by Dime Healthcare Co., Ltd.)
D: Tenstar Henna Color Treatment (manufactured by Sanpo Shoji Co., Ltd.)
E: Secret Color Natural Treatment (manufactured by Cosmex Roland Corporation)

The pH values in Table 2 are values measured using an AP-20 waterproof pH meter manufactured by A & D Co., Ltd., using a hair color treatment collected in an amount of 5 g each as a sample.

In Table 2, "non-peeling" means that peeling did not occur under the above test conditions. “Other delamination” means that layers different from the layer to be evaluated have been delaminated. "Pre-test peeling" means that the adhesion between the layers to be evaluated was already impaired in the laminated body after being stored for one month under the above conditions, and a meaningful measured value could not be obtained by the peeling test. Is shown.

As can be understood from Table 2, the laminate of the comparative example has an aluminum layer / adhesive layer and an aluminum layer / adhesive layer when a strongly acidic content having a pH of 4.0 or less or a content containing a branched higher alcohol is stored. At least one of the peel strength of the adhesive layer / sealant layers Ru impaired.

On the other hand, in the laminate of the present embodiment, the peel strength between layers is impaired regardless of whether the strongly acidic content having a pH of 4.0 or less or the content containing a branched higher alcohol is stored. To a lesser extent, it showed good resistance to these contents.

1 Outer layer 2 First adhesive layer 3 Aluminum layer 4 Second adhesive layer 5 Third adhesive layer 6 Sealant layer

Claims (6)

It has an outer layer, a first adhesive layer, an aluminum layer, a second adhesive layer, a third adhesive layer, and a sealant layer in this order.
The second adhesive layer contains 50% by weight or more of an ethylene-methacrylic acid copolymer.
The third adhesive layer contains an ethylene-acrylic acid copolymer in an amount of 50% by weight or more, and
The sealant layer is a layer made of straight chain low density polyethylene .
Laminated body. A container containing the molded product of the laminate according to claim 1. The container according to claim 2 , used for filling the contents selected from hair care products, cosmetics, and pharmaceuticals. The container according to claim 3 , wherein the content is selected from a content having a pH of 2.0 or more and 4.0 or less, and a content containing a branched higher alcohol. In the container according to claim 2,
Filled with content selected from hair care products, cosmetics, and pharmaceuticals,
Filling container. The filling container according to claim 5 , wherein the content is selected from a content having a pH of 2.0 or more and 4.0 or less, and a content containing a branched higher alcohol.

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