JPH0126629Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Application Field] The present invention is an easy-to-open liquid container, more specifically, a liquid container that is heat-sealed to a container body such as a cup to completely seal the liquid, and can be easily peeled and opened as needed. Regarding containers. [Prior art and its issues] As is well known, there are many products in which liquids, granules, powders, solids, etc. are stored in containers and then provided to customers with lids. , Apart from canned goods, etc., containers are used to make containers lighter and simpler, for example, as disclosed in Japanese Patent Application Laid-Open No. 48-98978 and Japanese Utility Model Application No. 53-114574,
Containers are increasingly made of paper or plastic, and their lids are often heat-sealed to the container body. There are various conditions required when heat-sealing this lid to the container body, but it must be easy to heat-seal, there should be no leakage of liquid contents after sealing, and the lid can be peeled off if necessary. When removing the package, the package can be easily peeled off and opened by hand. Furthermore, depending on the liquid content, the materials used for containers and lids, as well as the materials for heat sealing, may transfer the odor of the material or material to the liquid content, or may change the taste of the liquid content. It must not be something that could cause stains. In these respects, along with the need to make containers lighter and simpler, containers made of synthetic resin or paper with a synthetic resin layer are used as containers, and lids are heat-sealed to these containers. Such a container is suitable as a container for liquids, wet objects, or objects that do not like moisture absorption. There are various synthetic resins used for these, but polyester resins have particularly desirable properties, such as the ability to transfer odor to the liquid contents or change the taste of the liquid contents. However, when using polyester resin, there are problems with heat sealing properties when heat sealing it. However, the heat sealing strength is very high, and there are still issues with ease of opening. In view of these points, the purpose of this invention is to utilize the advantages of the properties of polyester resin while
As a result of intensive research and various experiments in order to obtain a container with good heat-sealing properties, we have found that once fused, the liquid contents are completely sealed, and the liquid contents will not leak or be contaminated. I have no intention of doing anything,
It is an object of the present invention to provide an easy-to-open container with good so-called easy-peel properties, which can be easily picked and peeled off by hand when it is desired to open the container. [Means for Solving the Problems] The structure of the present invention, which solves the problems of the prior art, is to print on the surface of aluminum foil, coat it with a transparent paint to protect the printing, and coat the back side of the aluminum foil with a transparent paint. A heat-sealing surface of the lid body formed by providing a polyester resin layer treated with a low melting point,
It is characterized in that the flange of the inner container, which is made of a polyester resin material with a normal melting point and which constitutes the container body, is heat-sealed. [Example] An example of the implementation of the present invention will be described below with reference to the accompanying drawings. First, an example of a container suitable for heat-sealing the lid will be explained with reference to FIG. 1. 1 is an outer container, and this outer container 1 has a paper container 2 coated with plastic 3 on both sides. The outer container 1 includes a body 4 and a
The body 4 and the bottom 5 are integrally bonded together. Reference numeral 6 denotes an inner container, which is molded from a polyester resin having a normal melting point, and is placed inside the outer container 1. Outer container 1
Flanges 7 and 8 are provided at the upper part of the inner container 6, and the flanges 7 and 8 are wound together in an overlapping state to form a flange portion 9. A container body 10 is constructed. Since a lid 20, which will be described below, is heat-sealed to the opening of the container body 10, the outer periphery of the back surface of the lid 20 is in contact with the flange 9 constituting the container body 10, and the contact portion is In order for the two to be heat-sealed, it is necessary to have a polyester resin layer with a normal melting point on the upper surface of the flange portion 9 of the container body 10. It does not matter if it is in any shape, such as , film, coated product, etc. Next, the lid body 20 shown in FIG.
4 is coated with a transparent paint 15, for example, a polyvinyl chloride paint. Further, a biaxially stretched polyester film 12 is laminated on the back side of the aluminum foil 11, and a polyester resin layer 13 that has been subjected to a low melting point treatment is provided on the back side of the biaxially stretched polyester film 12, so that the lid body 20 has a low melting point. The outer periphery of the treated polyester resin layer 13 is placed on the flange portion 9 of the container body 10 and heat-pressed to form the container body 10.
Seal the opening. To give a specific example of the above-mentioned polyester resin treated with a low melting point, polyester terephthalate (PET) resin with a normal melting point obtained by a conventional method has a melting point of 255 to 260°C, whereas a polyester resin with a melting point lower than this It is a polyester resin that has been modified and manufactured to have a low melting point of 200 to 250°C. Specifically, this is a polyester resin that is produced by copolymerizing an acid component or a glycol component with PET and a different component. For example, adding isophthalic acid to PET
The above polyester resin is obtained by copolymerizing up to 15 mol%. Further, as shown in FIG. 2, when a polyester resin layer 13 treated with a low melting point is laminated on a base material consisting of an aluminum foil 11 and a biaxially stretched polyester film 12, The aluminum foil 11 may be integrally laminated onto a two-layer film obtained by extruding a polyester resin having a normal melting point and a polyester resin treated with a low melting point according to the method and biaxially stretching the extruded resin. That is, to explain one example of the method for forming the lid body 20 of the present invention, a desired printing 14 is applied to the surface of a 40μ aluminum foil 11, and a polyvinyl chloride-based transparent paint 15 is coated on the printed surface. do. Separately, a polyester resin with a normal melting point and a polyester resin copolymerized with isophthalic acid (melting point 248°C) were extruded together, and this was biaxially stretched. A laminated film in which the polyester resin has a thickness of 5μ is obtained, and the top surface of this laminated film, a biaxially stretched polyester film 12 with a normal melting point, and the previously prepared aluminum foil 11 of 40μ are laminated together with an adhesive to form a lid. 20. In the above embodiment, a polyester resin layer 13 treated with a low melting point is provided on the heat sealing surface of the lid body 20.
However, such a low melting point treated polyester resin layer is used for the inner container 6 having the flange portion 9 that constitutes the container body 10, and a polyester resin layer with a normal melting point is applied to the heat sealing surface of the lid body 20. Since the same effect can be obtained even if layers are provided,
It is not limited to the examples. Next, regarding the heat sealing between the normal melting point polyester layer provided in the heat sealing part of the container body and the lid body having a low melting point treated polyester layer in the heat sealing part, we will discuss the heat sealing strength and easy peelability (easy opening). Table 1 shows the experimental results regarding

[Table] In this invention, when filling a container with liquid, there is a risk of liquid leakage if the amount is less than 1500g/15mm at a peeling angle of 180°, and 300/15
If the strength approaches 1.5 mm, the strength will be too high and it will be difficult to open the seal easily, so it is designed with a target of 2200 g/15 mm to 1500 g/15 mm. Now, when going into industrial production, there are many products that fall below the lower limit, and although the opening property is good, there remains some concern about the sealing property, so the easy peel property was marked with an ○. As for other data, experiments have yielded an easy-to-open liquid container that has both extremely good sealing performance and easy peelability.

[Effect of idea]

As described above, according to the configuration of the present invention, the following effects can be obtained. (a) The base material of the lid is aluminum foil, the surface of which is printed and coated with transparent paint to protect the printing, so the printed surface will not be damaged by handling during the distribution route. In addition, the presence of the paint layer adds rigidity to the aluminum foil, which not only facilitates the pressure bonding process to the container body, but also allows the aluminum foil's excellent light-shielding and gas barrier properties to When the liquid contained in the main body is a liquid such as sake that requires light shielding properties and gas barrier properties, it will not change in quality and reduce its taste. (b) By heat-sealing the polyester resin layer treated with a low melting point on the back of the lid and the flange of the inner container made of a polyester resin material with a normal melting point that constitutes the container body, the results shown in Tables 1 and 2 above are obtained. As is clear from the experimental results shown, since heat sealing is performed within the melting point temperature range of polyester resin treated with a low melting point, a liquid container with extremely good peelability can be obtained, and the liquid contained in the container can be easily peeled. Since all surfaces are made of polyester resin, when the liquid is sake, the resin odor will not transfer and change the taste.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view showing an example of the container body, and FIG. 2 is an enlarged longitudinal sectional front view showing an example of the lid body. 1... Outer container, 6... Inner container made of polyester resin with normal melting point, 7, 8... Flange, 9... Flange portion, 10... Container body, 11... Aluminum foil, 12... Normal melting point Biaxially stretched polyester film, 13... polyester resin layer subjected to low melting point treatment, 14... printing, 15... transparent paint, 20... lid body.

Claims (1)

[Scope of utility model registration request] The heat-sealed surface of the lid is formed by printing on the surface of the aluminum foil, coating it with a transparent paint to protect the printing, and providing a polyester resin layer treated with a low melting point on the back side of the aluminum foil, and the container. An easy-to-open liquid container characterized by heat-sealing the flange of an inner container made of a polyester resin material with a normal melting point, which constitutes the main body.