JPS5924946B2 - easy-open container - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an easily openable container, and more particularly to a container having an opening sealed so as to be peeled open by pressure from outside the container. This invention relates to an improved container.

Easy-open containers that are tightly sealed except for the opening, which is sealed so that it can be peeled open by pressure from the outside of the container, are used, for example, as containers that contain small amounts of seasonings and the like.

To make such an easy-to-open container, for example, a substance whose heat-sealing strength is largely dependent on temperature is applied or bonded to the entire surface of the base material or to each sealing part, and the temperature of each sealing part is adjusted during sealing. There is a method of weakening the sealing strength only at the opening by setting the temperature of the heat seal bar to a low temperature for the opening and a high temperature for other sealing areas, but with this method, it is difficult to adjust the temperature of the heat seal, and it is difficult to obtain The seal strength of the product is unstable. In order to overcome this drawback, various sealants have been developed that have a sealing strength that allows the container to be peeled open only at the opening when the container is pressed from the outside. However, none of these was fully satisfactory in terms of influence on the contents, durability, appropriate peelability, and the like. The present invention was discovered as a result of research on the above-mentioned easy-to-open containers. To provide an easily openable container which can be adjusted to the desired condition, does not affect the contents, and has excellent durability. That is, in the present invention, the container is tightly sealed except for the opening, which is sealed so that it can be peeled open by applying external pressure to the container and the contents are pushed out, and at least the inner surface of the opening is made of ethylene/vinyl acetate copolymer. The gist of the present invention is an easily openable container characterized in that the opening is sealed with a sealant containing a chlorinated polymer and an acrylic polymer as main components. Hereinafter, the above-mentioned present invention will be explained in detail.

The easily openable container of the present invention may have any shape, such as flat, cylindrical, or box-like. The opening of the container is sealed with an ethylene/vinyl acetate copolymer layer (hereinafter referred to as the inner surface treatment layer) provided on the base material forming the container inside, and the rest of the container is sealed with the exception of the opening. Depending on the shape and manufacturing method of the container, the container may be sealed using an adhesive, heat sealing, ultrasonic sealing, high frequency sealing, etc., or the entire container may be integrally molded and there is no sealing part other than the opening. Items must be tightly sealed except for the opening; that is, when external pressure is applied to the container, only the opening will peel off the seal, while the other parts will remain intact. It is necessary that
Figures 1 and 2 show an example of an easily openable container of the present invention. Figure 1 is a plan view of the container, and Figure 2 is an A-A line in the plan view. FIG.

This container consists of two sheets of material having an inner surface treatment layer 2 on the entire surface of one side of a base material 1, which are placed facing each other with the inner surface treatment layer 2 inside, sandwiching the contents 3, and opening 4 and a seal portion other than the opening. It is sealed by sealing 5. The inner surface treatment layer 2 is adhered to the opening via a sealing agent 6 (hereinafter referred to as an opening sealing agent) whose main components are a chlorinated polymer and an acrylic polymer. On the other hand, the seal portion 5 other than the opening
The inner surface treatment layer 2 is sealed by heat sealing, ultrasonic sealing, high frequency sealing, or the like.

In addition, when the inner surface treatment layer 2 is provided only on the opening, or when the inner surface treatment layer 2 is not sufficiently sealed by the above-mentioned sealing method, the seal 5 other than the opening may be made with a stronger sealant than the above-mentioned opening sealant. Of course, the container can be sealed using an adhesive that does not peel off when external pressure is applied to the container.

The base material used above is flexible and deforms under external pressure, such as paper, synthetic resin, or metal foil, depending on the content.
These are used as a laminate if necessary.

Next, the ethylene/vinyl acetate copolymer used as the inner surface treatment layer not only imparts favorable peelability to the opening, but also has sealability by heat sealing, ultrasonic sealing, or high frequency sealing, so it If provided on the entire inner surface of the material, areas other than the openings can be easily sealed.

The copolymer preferably has a vinyl acetate content of 5 to 20% by weight. This inner surface treatment layer can be provided by conventional means such as lamination or coating. Further, it is sufficient that this inner surface treatment layer is provided at least in the opening, and it goes without saying that it is not necessary to provide the inner surface treatment layer if the base material itself is made of the material that constitutes the inner surface treatment layer. . In the above, the sealing agent for the opening is mainly composed of a chlorinated polymer and an acrylic polymer, and may also contain an epoxy resin, a stabilizer or plasticizer such as epoxidized soybean oil, or other additives as necessary. It is something.

As the chlorinated polymer, those having a chlorine content of 10 to 80%, preferably 60 to 70%, such as chlorinated rubber, chlorinated polyethylene, or chlorinated polypropylene, are used. These chlorinated polymers may be used alone or in combination. On the other hand, acrylic polymers are homopolymers of acrylic acid derivatives, copolymers of acrylic acid derivatives and other monomers, or homopolymers of methacrylic acid derivatives or copolymers of methacrylic acid derivatives and other monomers. It is one kind or a mixture of more than one kind. Specific examples of these include methyl acrylate polymer, methyl methacrylate polymer, methyl acrylate/acrylonitrile copolymer, methyl methacrylate/acrylonitrile copolymer, acrylonitrile, and butadiene rubber. Most of the chlorinated polymers constituting the opening sealant used in the present invention exhibit strong adhesion to the inner surface treatment layer formed by ethylene/vinyl acetate copolymer, while acrylic polymers Shows almost no adhesion. These two types of polymers, which have contradictory properties in terms of heat-sealability to the inner surface treatment layer, have extremely good compatibility, so it can be easily achieved by blending these polymers or by changing the blend ratio. It is possible to set the desired adhesive strength. Acrylic polymer/
When the blend ratio of the chlorinated polymer is within the range of 10 to 50, it is possible to obtain the desired adhesive strength or releasability when pressing the container. The sealant for the opening can be provided on the inner surface treatment layer of the opening by dissolving the sealant in a solvent and using a conventional coating or coating method. As is clear from the above description, the easy-open container of the present invention exhibits appropriate peelability at the opening when the container is pressed due to the combination of the opening inner surface treatment layer and the opening sealant. The properties can be freely adjusted by changing the blend ratio of chlorinated polymer and acrylic polymer.

Furthermore, the opening sealant used in the present invention has various excellent properties such as chemical resistance, durability, and uniformity of peeling. If such an easily openable container is used, for example, for a container containing a small amount of seasoning, the contents can be easily taken out without contaminating the surrounding area. As described above, the easily openable container of the present invention can be used as a container for various contents, such as foods, adhesives, cosmetics, etc. Next, the present invention will be described in more detail with reference to Examples. Examples Nylon (15μ) and ethylene/
A laminated film with vinyl acetate copolymer (vinyl acetate content: 10%) (50μ) was used.

This base material was laminated using a known dry lamination method. An opening sealing agent having the following composition was applied by a gravure method to a portion of this base material corresponding to the opening on the ethylene/vinyl acetate copolymer side. [Sealant for openings (1)]
The coated material was slit into a predetermined width, and was then passed through a filling machine set at a heat-sealing temperature of 140° C. to fill with mayonnaise.

When the container containing this mayonnaise was crushed by hand, the contents could be easily removed without contaminating the surrounding area. The strength of each seal portion at this time was as shown below for the opening sealants (1) and (2).

[Brief explanation of drawings]

Fig. 1 is a plan view showing an example of an easily openable container of the present invention, and Fig. 2 is a sectional view taken along line A-A'' in Fig. 1. ... Base material, 2 ... Ethylene-vinyl acetate copolymer layer,
3...Contents, 4...Opening, 5...
... Seal parts other than openings, 6... Seal agent for openings.

Claims (1)

[Claims] 1 A container that is tightly sealed except for the opening, which is sealed so that it can be peeled open and the contents pushed out by applying external pressure to the container, and at least the inner surface of the opening is made of ethylene/vinyl acetate copolymer. An easily openable container characterized in that the opening is sealed with a sealant containing a chlorinated polymer and an acrylic polymer as main components.