JPH06238840A - Packaging material excellent in resistance to chemical - Google Patents

Abstract

PURPOSE:To enable a packaging material to have suitable gas barrier properties without causing any peeling and the like of a gas barrier layer against various kinds of medicines and chemicals. CONSTITUTION:A packaging material comprises an ethylene-vinyl acetate copolymer saponified substance layer, a gas barrier layer having a nylon layer and including a co-extruded film, which is provided on both the sides of the saponified substance layer, and a heat-sealable resin layer laminated on each gas barrier layer via a thermally meltable resin layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packaging material having excellent chemical resistance, which is used in containers for various chemicals such as photographic developing solutions.

[0002]

2. Description of the Related Art In general, packaging materials used for various containers are often selected with an emphasis on having barrier properties with respect to contents, and particularly for contents such as foods, preservation of the contents. Not only is a high barrier layer used, including barrier properties against oxygen and water vapor. As such a barrier layer, a metal foil such as aluminum, a polyvinylidene chloride coated resin film, a film obtained by vapor deposition of an inorganic substance such as silicon oxide, etc. are generally used, and these are usually laminated with an adhesive. Met.

However, when such a packaging material is used, the resistance to the organic solvent contained in the content of the barrier layer and the pH resistance of the content have not been particularly taken into consideration. Also, even if the pH of the contents is acidic or alkaline, its value is limited in advance, so it is possible to design and use a packaging material that uses a barrier layer that matches this value. Met.

[0004]

However, when applying these packaging materials to various chemicals, etc.,
That is, when the pH value can change over a wide range from the acidic range to the alkaline range, a packaging material that can be applied only in a specific pH range is insufficient. In particular, in the case of having a barrier layer as described above, it is preferable that the volatile components of the contents stay near the barrier layer, particularly between the layers in the barrier layer, and as a result, attack the adhesive and corrode metals such as aluminum. There have been problems such as causing a phenomenon that does not occur or causing delamination between layers.

Conventionally, containers for chemicals or the like are usually plastic bottles of polyvinyl chloride, polyethylene, etc. However, regarding these, disposal of the containers after use of the chemicals causes environmental problems. It was

That is, the object of the present invention is to prevent various chemicals from peeling off the gas barrier layer, etc.
And to provide a packaging material having an appropriate gas barrier property.

Another object of the present invention is to provide a packaging material for chemicals, which has less problems in environmental protection than the conventional ones.

[0008]

The above object of the present invention is to provide a hot melt resin layer on a gas barrier layer including a coextruded film having a saponified ethylene-vinyl acetate copolymer layer and nylon layers provided on both sides thereof. It is achieved by providing a packaging material obtained by laminating a heat-sealable resin layer via the.

The present invention will be described in more detail below.

The gas barrier layer in the present invention includes a layer having a nylon (hereinafter referred to as Ny) layer on both sides of an ethylene-vinyl acetate saponified (hereinafter referred to as EVOH) layer,
It is obtained by co-extrusion, but preferably has a heat-sealable resin layer such as linear low density polyethylene (hereinafter referred to as LLDPE) on at least one Ny layer, for example Ny / EVOH / Ny / It has a configuration such as LLDPE, LLDPE / Ny / EVOH / Ny / LLDPE.

The packaging material of the present invention comprises the above gas barrier layer laminated with a heat-sealing resin layer such as LLDPE via a hot-melt resin layer such as sand polyethylene (hereinafter referred to as s-PE). Is. Further, in the present invention, high density polyethylene (hereinafter referred to as HDP) is provided between the gas barrier layer and the heat-sealable resin layer via the same hot-melt resin layer as described above in order to impart rigidity as a packaging material.
A structure provided with a layer (for example, E), for example, (LLDPE) / Ny / EVOH / Ny / LLDPE /
A configuration such as s-PE / HDPE / s-PE / LLDPE can also be adopted.

The packaging material of the present invention can usually be produced by laminating the above gas barrier layer on the inside of the base material, that is, on the side in contact with the contents. PE as the base material used
A plastic film such as T or drawn nylon, a laminate of a plastic film and paper, or the like is used.

The packaging material of the present invention can be used as a bag containing a standing pouch or the like or a container including a paper container, and these can be applied to various chemicals such as a developing solution and a perm solution.

[0014]

By using a gas barrier layer having nylon layers on both sides of the EVOH layer as in the present invention, it is possible to impart appropriate gas barrier properties and mechanical strength such as puncture and drop strength. It is possible to obtain an excellent packaging material as a bag or a container. Further, as a result, the volatile components of the contents can escape to the outside to some extent, so that delamination resulting from this can be prevented. Further, in the present invention, by coextruding these gas barrier layers, it is possible to laminate without using an adhesive,
It is possible to prevent peeling that occurs when the adhesive is attacked. Further, it becomes possible to reduce the film thickness. Further, by using the hot-melt resin layer in the lamination of the gas barrier layer and the heat-sealing resin layer as the inner layer, peeling due to the use of the adhesive can be similarly prevented.

[0015]

EXAMPLES The present invention will be described in more detail with reference to the following examples.

Example 1 A gas barrier layer having a composition of Ny / EVOH / Ny / LLDPE was coextruded, LLDPE was laminated on the inside of the gas barrier layer via s-PE, and PET was used as a substrate on the outside of the gas barrier layer by a dry lamination method. Was laminated to prepare a packaging material having the following constitution, which was used as a main body of a standing pouch for 500 ml.

PET / [[Ny / EVOH / Ny / LLDPE] / s-PE / LLDPE ^{(12 μm) (5 μm) (5 μm) (5 μm) (5 μm) (20 μm) (80 μm)}

Further, a gas barrier layer having the same constitution as described above is coextruded, LLDPE is laminated on the inner side in the same manner, and stretched nylon (ONy) is laminated on the outer side as a base material by a dry lamination method to form a package having the following constitution. A material was prepared, and this was used as a bottom tape of the standing pouch, and a standing pouch for 500 ml was prepared together with the main body prepared above.

ONy // [Ny / EVOH / Ny / LLDPE] / s-PE / LLDPE ^{(25 μm) (5 μm) (5 μm) (5 μm) (5 μm) (20 μm) (80 μm)}

Stock solution A (pH = 9.0) of a color developing agent for iron chloride to be used by mixing with the obtained standing pouch,
Stock solution B (pH = 1.5) and stock solution C (pH = 14.0) were each filled in 500 ml and sealed, and a storage test was carried out for 1 month under the conditions of 50 ° C and 35% RH.

At the same time, a standing pouch was prepared in the same manner as the conventional packaging material having the following constitution, and the stock solutions (A, B and C) were similarly filled, and a 1-month storage test was conducted. . The results of the storage test are shown in Table 1.

Comparative Example 1 PET // Al foil // ONy // LLDPE ^{(12 μm) (9 μm) (15 μm) (80 μm)} Comparative Example 2 PET // K-ONy // LLDPE ^{(12 μm) (15 μm) (80 μm)} Comparative Example 3 ONy // EVOH // LLDPE ^{(15 μm) (15 μm) (80 μm)}

The above // indicates that the layers were laminated by the dry lamination method, and 2.5 g / m ^{2 of} urethane type two-component curable adhesive Adcoat 301A / B (manufactured by Toyo Morton) was applied and laminated. K-ONy: Vinylidene chloride resin coated stretched nylon

[0024]

[Table 1]

Example 2 HDPE was laminated via s-PE on the inside of the same gas barrier layer as in Example 1, and LLDPE was further laminated on the HDPE via s-PE. Further, PET as a base material was laminated on the outside of the gas barrier layer by a dry lamination method to prepare a packaging material having the following constitution, which was used as a main body of a 1000 ml standing pouch.

PET // [Ny / EVOH / Ny / LLDPE] / s-PE / HDPE / ^{(12 μm) (5 μm) (5 μm) (5 μm) (5 μm) (20 μm) (40 μm)} s-PE / LLDPE ^{(20 μm) ) (80 μm)}

Using this and the bottom tape prepared in the same manner as in Example 1, a standing pouch for 1000 ml was prepared. When this was evaluated in the same manner as in Example 1, it was found that there was no peeling between layers and the chemical resistance was excellent.

[0028]

As described in detail above, according to the present invention, a packaging material having an appropriate gas barrier property can be obtained without causing peeling of the gas barrier layer against various chemicals. Is suitable for materials such as bags and containers.

Further, the packaging material of the present invention contributes to resource saving such as material saving and cost reduction, and is more environmentally friendly in terms of disposal, incineration, etc., as compared with those used for conventional chemical containers. Excellent in protection.

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Claims (1)

[Claims] 1. A heat-sealable resin layer is laminated on a gas barrier layer including a coextruded film having a saponified ethylene-vinyl acetate copolymer layer and nylon layers provided on both sides of the layer, with a heat-meltable resin layer interposed therebetween. Packaging material.