JP7505264B2 - Hair color packaging bag - Google Patents

Description

The present invention relates to a packaging bag for hair coloring agents, and to a packaging bag in which pinholes are unlikely to occur in the barrier layer of the packaging material.

Packaging bags with high oxygen barrier properties have been known for some time in the fields of medicines, food, electronic materials, and the like, for packaging contents whose quality deteriorates when oxygen penetrates them (see, for example, Patent Document 1). One example of a content that is easily affected by oxygen is hair dye. Hair dye easily oxidizes and discolors, and has high permeability due to the inclusion of monoethanolamine, etc., so packaging bags need to have high barrier properties, and packaging bags that combine metal foils such as aluminum foil are often used.

However, it is known that metal foils such as aluminum foil can corrode when exposed to highly acidic or alkaline contents such as hair dyes, resulting in the formation of tiny pinholes. When pinholes form, the barrier properties deteriorate, allowing oxygen to penetrate through these areas and causing spotted discoloration in the hair dye. For this reason, metal foils such as aluminum foil are subjected to a chemical conversion treatment.

For example, Patent Document 2 discloses a packaging material for hair dyes in which aluminum foil and a sealant film are bonded together by extruding a thermoplastic resin, thereby preventing delamination caused by the hair dye, and the aluminum foil surface is treated to prevent corrosion.

One such surface treatment involves applying an acrylic resin containing zirconium atoms to form a coating.

However, when a surface treatment layer of such an acrylic resin containing zirconium atoms is formed on the surface of the aluminum foil, a problem occurs in that the resin cannot be firmly adhered to the surface treatment layer.

JP 2008-56289 A Patent No. 4945871

The present invention was made based on these circumstances, and aims to provide a packaging bag for hair coloring agents that has a barrier layer made of a metal or alloy in its layer structure, a surface treatment layer of an acrylic resin containing zirconium atoms formed on the surface of this barrier layer, and further, has a resin firmly bonded to this surface treatment layer.

As mentioned above, it was difficult to firmly adhere resin to the surface treatment layer of acrylic resin containing zirconium atoms, but the inventors discovered that the reason for this was that the acrylic resin contained chemical groups that reacted with and consumed the isocyanate compound contained in the adhesive, and therefore the adhesive did not cure sufficiently. For example, hydroxyl groups.

Therefore, the present invention uses an acrylic resin that does not have a chemical group that reacts with an isocyanate compound, making it possible to firmly adhere the resin to the surface treatment layer.

That is, the invention described in claim 1 is a packaging bag for hermetically packaging a hair color agent containing monoethanolamine, the packaging bag having a barrier layer made of a metal or alloy in its layer structure and a sealant layer disposed as the innermost layer, a surface treatment layer is provided on the surface of the barrier layer, and an adhesive layer is provided in contact with this surface treatment layer, the adhesive layer is formed by curing an adhesive containing an isocyanate compound, and the surface treatment layer is formed of an acrylic resin containing zirconium atoms and having no hydroxyl groups.

The invention described in claim 2 is the packaging bag for hair coloring agents described in claim 1, characterized in that the isocyanate compound is made of a derivative of an isocyanate monomer obtained by trifunctionalizing a difunctional isocyanate monomer.

The invention described in claim 3 is the hair coloring agent packaging bag described in claim 1 or 2, characterized in that the barrier layer is made of aluminum or an aluminum alloy having a thickness of 5 to 50 μm.

The invention described in claim 4 is the packaging bag for hair coloring agents described in any one of claims 1 to 3, characterized in that an extruded resin layer is disposed in contact with the adhesive layer, the sealant layer is adhered by this extruded resin layer, and the laminate strength between the sealant layer and the barrier layer is 3.0 mN/15 mm width or more.

The invention described in claim 5 is the packaging bag for hair coloring agents described in any one of claims 1 to 4, characterized in that the extruded resin layer is made of a thermoplastic polyethylene resin having a thickness of 15 to 30 μm.

The invention described in claim 6 is the hair coloring agent packaging bag described in any one of claims 1 to 5, characterized in that the sealant layer has a thickness of 20 to 80 μm.

In the present invention, the acrylic resin contained in the surface treatment layer is an acrylic resin that does not have a chemical group that reacts with an isocyanate compound, so the isocyanate compound contained in the adhesive is not consumed. This has the effect of allowing the adhesive to cure sufficiently and firmly bond the surface treatment layer and the resin layer.

1 is a schematic cross-sectional view showing an example of a layer structure of a laminate constituting the hair color agent packaging bag of the present invention. FIG.

The following describes in detail an embodiment of the present invention with reference to the drawings. Note that the present invention is not limited to the embodiment described below.

Figure 1 is a schematic cross-sectional view showing an example of the layer structure of the laminate 1 constituting the hair coloring agent packaging bag of the present invention (hereinafter also referred to simply as the packaging bag). The packaging bag is configured in a bag shape by laminating the laminate 1, in which the printing base layer 11, the ink layer 12, the intermediate base layer 13, the barrier layer 14, the surface treatment layer 15, the adhesive layer 16, the extruded resin layer 17, and the sealant layer 18 are laminated in this order, with the sealant layers 18 facing each other and the periphery bonded together by heat sealing, and by providing a storage section inside. In addition, a separate spout member, nozzle, spout, cap, etc. may be appropriately attached for pouring out the contents.

[Printing substrate layer 11]
The printing substrate layer 11 is not particularly limited as long as it is a plastic film having heat resistance, suitability for lamination, and suitability for printing. Specifically, polyolefin (polyethylene, polypropylene, etc.), polyester (polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc.), polyamide (nylon-6, nylon-66, etc.), polyimide, etc. can be used, and may be appropriately selected depending on the required specifications.

Although there is no particular limitation regarding the thickness, a stretched film obtained by biaxial stretching is usually used, and a thickness in the range of 9 μm to 50 μm is preferable. The substrate layer may be a single layer using only one of the above types, or a multilayer using two or more types.

[Ink layer 12]
The ink layer 12 may be a concealing layer, or may have various text information, pictures, designs, etc., and can be provided by appropriately selecting a known printing method, such as gravure printing, offset printing, silk screen printing, inkjet printing, etc.

[Intermediate substrate layer 13]
By using a resin for the intermediate substrate layer 13 that has a solubility parameter (SP value) significantly different from that of monoethanolamine, which is a main component of the hair color agent, compatibility is reduced, and even if a pinhole occurs for some reason in the barrier layer 14 made of a metal or alloy provided on the inner layer side, the hair color agent can be prevented from penetrating into the ink layer and printed substrate layer on the outer layer side, and the barrier property can be prevented from being reduced at the pinhole area, thereby preventing the occurrence of spot-like discoloration or the like in the content hair color agent.

The SP value of monoethanolamine is 16.3, and it was found that a sufficient difference can be obtained by using a resin constituting the intermediate substrate layer 13 with an SP value of less than 11. Specific examples include polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyvinyl acetate (PVAC), polyethylene (PE), polypropylene, polystyrene, polycarbonate, polyurethane, polymethyl methacrylate, vinyl chloride-vinyl acetate copolymer resin, ethyl cellulose, cellulose acetate, and epoxy resin. Metal vapor deposition or inorganic vapor deposition may also be performed on the intermediate substrate layer 13.

The thickness of the intermediate substrate layer 13 is not particularly limited, but is preferably in the range of 8 μm to 50 μm.

[Barrier layer 14]
The barrier layer 14 is a layer made of metal foil, and the material of the metal foil may be aluminum, copper, iron, stainless steel, etc., but among them, aluminum or an aluminum alloy is particularly preferable from the viewpoint of versatility and flexibility. Furthermore, the thinner the metal foil, the more likely it is that pinholes will occur, so the thickness is preferably 5 μm to 50 μm in order to ensure the necessary barrier properties.

If the packaging bag is to have dead-hold properties to prevent oxygen from entering through an airbag that occurs after the contents are pushed out and ejected, it is even more preferable for the thickness to be 12 μm or more in the case of aluminum foil.

[Surface treatment layer 15]
The surface treatment layer 15 is provided to prevent delamination between the metal foil constituting the barrier layer 14 and the adjacent layer, which may occur when the hair color agent leaches out, and is required to be formed by applying an acrylic resin containing zirconium atoms.

In addition, if the acrylic resin has hydroxyl groups (OH groups) or the like, the isocyanate compounds contained in the adhesive that forms the adhesive layer 16 will react with these hydroxyl groups (OH groups) and be consumed, reducing the laminate strength between the metal foil and the resin layer. Therefore, it is necessary that the acrylic resin does not have chemical groups that react with isocyanate compounds such as hydroxyl groups (OH groups).

As an example of an acrylic resin that contains zirconium atoms and does not have a chemical group that reacts with an isocyanate compound, Surfcoat 147/148 manufactured by Nippon Paint Surf Chemicals Co., Ltd. can be used.

[Adhesive layer 16]
The adhesive layer 16 is preferably made of a trifunctional derivative such as an adduct type in which various diisocyanate monomers such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, xylylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, 4,4'-diphenylmethane diisocyanate and hydrogenated products thereof are reacted with trifunctional active hydrogen-containing compounds such as trimethylolpropane and glycerol, a biuret type in which the monomers are reacted with water, or a trimer (isocyanurate) type that utilizes self-polymerization of an isocyanate group, which has high resistance to highly penetrating contents and is less likely to cause delamination. Moreover, a derivative having even more functionality can also be used.

The thickness of the adhesive layer 16 is not particularly limited, but from the viewpoint of adhesive strength, it is preferably 10 nm to 500 nm, and more preferably 100 nm to 250 nm.

[Extruded resin layer 17]
The extruded resin layer 17, in cooperation with the surface treatment layer 15 and the adhesive layer 16, plays a role in firmly adhering the barrier layer 14 and the sealant layer 18. That is, the surface treatment layer 15 is provided in contact with the barrier layer 14, and the adhesive layer 16 is provided in contact with the surface treatment layer 15. Then, a molten resin is extruded between the adhesive layer 16 and the sealant layer 18, and the adhesive layer 16 and the sealant layer 18 are pressed together with the extruded resin layer 17 made of this resin interposed therebetween, whereby the barrier layer 14, the surface treatment layer 15, the adhesive layer 16, the extruded resin layer 17, and the sealant layer 18 can be integrated together.

When the surface treatment layer 15 is made of an acrylic resin that contains zirconium atoms and has no chemical groups that react with an isocyanate compound, and the adhesive layer 16 is formed by curing an adhesive that contains an isocyanate compound, the sealant layer 18 and the barrier layer 14 can be firmly bonded together with a high lamination strength of 3.0 mN/15 mm width or more.

For the extrusion resin layer 17, a thermoplastic polyethylene resin is preferably used, and examples include high-density polyethylene, low-density polyethylene, linear low-density polyethylene, and medium-density polyethylene. The thickness is preferably 15 μm or more and 30 μm or less.

[Sealant layer 18]
The sealant layer 18 is a layer made of a polyethylene-based resin, a polypropylene-based resin, etc. Specifically, the sealant layer 18 is made of a single resin selected from ethylene-based resins such as high-density polyethylene, low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, and ethylene-α-olefin copolymers, homo-block-random polypropylene resins, propylene-based resins such as propylene-α-olefin copolymers, ethylene-α,β-unsaturated carboxylic acid copolymers such as ethylene-acrylic acid copolymers and ethylene-methacrylic acid copolymers, esters of ethylene-α,β-unsaturated carboxylic acid copolymers such as ethylene-methyl acrylate, ethylene-ethyl acrylate, ethylene-methyl methacrylate, and ethylene-ethyl methacrylate, ion-crosslinked ethylene-α,β-unsaturated carboxylic acid copolymers in which the carboxylic acid moieties are crosslinked with sodium ions or zinc ions, acid anhydride-modified polyolefins such as ethylene-maleic anhydride graft copolymers and ethylene-ethyl acrylate-maleic anhydride terpolymers, epoxy compound-modified polyolefins such as ethylene-glycidyl methacrylate copolymers, and ethylene-vinyl acetate copolymers, or a blend of two or more of these resins.

Various additives (antioxidants, tackifiers, bulking agents, various fillers, etc.) may be added to these constituent materials as necessary. From the viewpoint of pinhole resistance, the thickness of the sealant layer 18 is preferably 20 to 80 μm.

In a packaging bag made by bonding together the laminate 1 constructed as described above, the acrylic resin contained in the surface treatment layer is an acrylic resin that does not have a chemical group that reacts with an isocyanate compound, so the adhesive cures sufficiently and can firmly bond the surface treatment layer 15 and the extruded resin layer 17. As a result, the entire layer from the printing substrate layer 11 to the sealant layer 18 is firmly integrated.

In addition, the surface treatment layer 15 is made of an acrylic resin containing zirconium atoms, and since this surface treatment layer 15 is provided on the barrier layer 14, even when a hair color agent containing monoethanolamine is sealed and packaged, delamination does not occur between the barrier layer 14 and the layer adjacent to it.

<Example>
A stretched nylon (ONY) film (Koujin, Bonyl W, thickness 15 μm) was used as the printing substrate layer 11, and a white printing layer was provided by gravure printing to form the ink layer 12.
As the intermediate substrate layer 13, a polyethylene terephthalate (PET) film (manufactured by Futamura Chemical, FE2001, thickness 12 μm) was used.

Also, aluminum foil (manufactured by Toyo Aluminum, material 8079, thickness 9 μm) was used as the barrier layer 14.

Then, using a urethane adhesive (main agent: Takelac A626, manufactured by Mitsui Chemicals; hardener: Takenate A50, manufactured by Mitsui Chemicals), the printing substrate layer 11, the ink layer 12, the intermediate substrate layer 13, and the barrier layer 14 were laminated in this order to produce an intermediate laminate.

Next, Surfcoat 147/148 manufactured by Nippon Paint Surf Chemicals was used as the acrylic resin, and this acrylic resin was applied to the surface of the barrier layer 14 of the intermediate laminate to form the surface treatment layer 15.

Next, an adhesive containing biuret type hexamethylene diisocyanate as the main component was used as the adhesive, and this was applied onto the surface treatment layer 15 to form an adhesive layer 16.

Next, low-density polyethylene (LDPE) (manufactured by Nippon Polyethylene, LC600A) was used as the resin constituting the extruded resin layer 17, and linear low-density polyethylene (LLDPE) (manufactured by Futamura Chemical, LL-MTNST) was used as the sealant layer 18. The LDPE was then heated and melted, and extruded into a film between the adhesive layer 16 and the sealant layer 18, and the entire structure was pressed to integrate them, thereby producing the laminate 1.

Comparative Example
A laminate 1 was produced in the same manner as in the Example, except that Surfcoat EC1000A/B manufactured by Nippon Paint Surf Chemicals was used as the acrylic resin constituting the surface treatment layer 15.

Surfcoat EC1000A/B is an acrylic resin that contains zirconium atoms (Zr) and has OH groups.

<Evaluation>
For the laminates of the examples and the comparative examples, a tensile tester was used to peel the barrier layer 14 from the extruded resin layer 17, and the laminate strength was measured. The results are shown in Table 1.

From these results, it can be seen that the laminate strength is higher when the surface treatment layer 15 is made of an acrylic resin that does not have a chemical group that reacts with an isocyanate compound (Example).

1: Laminate 11: Printing substrate layer 12: Ink layer 13: Intermediate substrate layer 14: Barrier layer 15: Surface treatment layer 16: Adhesive layer 17: Extruded resin layer 18: Sealant layer

Claims (6)

A packaging bag for hermetically packaging a hair color agent containing monoethanolamine, the packaging bag having a barrier layer made of a metal or alloy in its layer structure and a sealant layer disposed as the innermost layer, a surface treatment layer being provided on the surface of the barrier layer, and an adhesive layer being provided in contact with this surface treatment layer, the adhesive layer being formed by curing an adhesive containing an isocyanate compound, and the surface treatment layer being formed of an acrylic resin containing zirconium atoms and having no hydroxyl groups. The hair coloring agent packaging bag according to claim 1, characterized in that the isocyanate compound is a derivative of an isocyanate monomer obtained by trifunctionalizing a difunctional isocyanate monomer. The hair coloring agent packaging bag according to claim 1 or 2, characterized in that the barrier layer is made of aluminum or an aluminum alloy having a thickness of 5 to 50 μm. The hair coloring agent packaging bag according to any one of claims 1 to 3, characterized in that an extruded resin layer is disposed in contact with the adhesive layer, the sealant layer is adhered by the extruded resin layer, and the laminate strength between the sealant layer and the barrier layer is 3.0 mN/15 mm width or more. The hair coloring agent packaging bag according to any one of claims 1 to 4, characterized in that the extruded resin layer is made of a thermoplastic polyethylene resin having a thickness of 15 to 30 μm. The hair coloring agent packaging bag according to any one of claims 1 to 5, characterized in that the sealant layer has a thickness of 20 to 80 μm.

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