JPS6345307Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a lid material, and more particularly to a lid material mainly used for forming an easy-to-open molded lid for liquor containers.

Generally, sake cup packaging involves hot filling, so vacuum absorption is essential. Currently, in almost all cases, the vacuum absorbent part is formed by molding the lid to form the vacuum absorbent part. However, in this case, the lid material is thick because it is molded, and during heat sealing, it is difficult for the heat of the seal bar to be transmitted through the lid material to the sealing surface, and it is easy to cause uneven heat.
In extreme cases where the seal is unstable, a seal failure may occur where the seal is not formed locally, so-called seal failure.

Furthermore, there are almost no heat sealing layers with stable sealing strength, and there are currently no lidding materials for liquors provided with a sheet sealing layer that does not contain low molecular weight and has little odor.

From these points of view, it is desired to create an easy-to-open lid material for alcoholic beverages that uses a heat-sealing layer that maintains shape retention, reduces the thickness of the lid material, and has stable heat-sealability.

As a result of research to develop a molded lid for liquor containers that retains its shape, exhibits stable heat-sealability, stable and good ease of opening, and has oxygen barrier properties, the inventor found that the top layer According to a lid material comprising a polybutylene terephthalate film as an intermediate layer, a polyvinylidene chloride coated unstretched nylon film as an intermediate layer, an unstretched polypropylene film as an intermediate layer, and a polyethylene-polypropylene blend polymer film as a bottom layer, it is suitable for use in liquor containers as described above. It was discovered that a molded lid could be obtained, and the present invention was completed based on this knowledge.

That is, the gist of the present invention is that it consists of a polybutylene terephthalate film as the top layer, a polyvinyline chloride coated unstretched nylon film and unstretched polypropylene film as the middle layer, and a polyethylene-polypropylene blend polymer film as the bottom layer. This is the lid material.

Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 shows a lid material 5 according to the present invention.

The lid material of the present invention consists of a polybutylene terephthalate film 1 as the top layer, a polyvinylidene chloride coated unstretched nylon film 2 and an unstretched polypropylene film 3 as the middle layer, and a polyethylene-polypropylene blend polymer film 4 as the bottom layer. It is.

Therefore, in the present invention, the polybutylene terephthalate film 1 is laminated to impart properties such as moldability, heat resistance, and shape retention to the lid material, and the thickness thereof is preferably 30 to 150μ, and 30μ or less. If it is 150μ or more, pinholes and holes will occur in the corners of the molded product, and the shape retention will be poor, making it impossible to maintain the shape of the lid.If it is 150μ or more, excessive heat will be generated during heat sealing. This is undesirable because it becomes difficult, tends to cause poor heat sealing, and increases costs. Next, the polyvinylidene chloride coated unstretched nylon film 2 is laminated to provide oxygen barrier properties to the lid material.
50μ is preferable; if it is less than 20μ, pinholes and perforations will occur at the corners during molding, and the barrier effect will be lost, so it is not preferable; if it is more than 50μ, nylon does not have good moldability, so it is difficult to mold the entire lid material. This is not preferable because the properties deteriorate and the corner portions cannot be formed sharply.

Next, the unstretched polypropylene film 3 is laminated to give rigidity and cushioning properties to the lid material, and its thickness is preferably 20 to 100μ, and if it is less than 20μ, there will be pin holes in the corners during molding. This is not preferable because it causes holes and there is no cushioning effect, and when it is more than 100μ, it is difficult to transmit heat during heat sealing, which tends to result in poor heat sealing, which is not preferable.

The polyethylene-polypropylene blend polymer film functions as a heat-sealing layer, and its thickness is preferably 10 to 100μ.If it is less than 10μ, the peel strength after heat fusion will be below practical strength, so it is not preferable, and if it is 100μ or more. In this case, not only the cost increases, but also the film forming property is extremely deteriorated, which is not preferable. Moreover, if it exceeds 100 μm, stringiness and fluffing will appear on the flange of the container after opening, which is not preferable.

In addition, the blend ratio of polyethylene and polypropylene is preferably 7:3 to 3:7, and when the amount of polyethylene increases and the blend ratio becomes 7:3 or more, cohesive failure does not occur and interfacial peeling occurs, and the heat seal strength is It is undesirable because it fluctuates depending on the temperature and is unstable. If the amount of polypropylene is too large and the blend ratio is less than 3:7, it is undesirable because complete fusion occurs and easy opening properties are lost.
Further, the ease of opening is the best when the blend ratio of polyethylene to polypropylene is 5:5.

Polyethylene-polypropylene blend polymer film does not contain low molecular weight substances, so it has little odor and is suitable for packaging alcoholic beverages.

FIG. 2 shows another example 6 of the present invention.

This example of the present invention differs from the one shown in Figure 1 in that the stacking order of the polyvinylidene chloride coated unstretched nylon film 2 and the unstretched polypropylene film 3 is reversed.

A polybutylene terephthalate film 1, a polyvinylidene chloride coated unstretched nylon film 2, an unstretched polypropylene film 3, and a polyethylene-polypropylene blend polymer film 4 are laminated in the lamination order shown in FIG. The lid material of the present invention can be obtained by dry laminating using an agent.

FIG. 3 shows an example of a molded lid formed using the lid material 5 of the present invention shown in FIG.

FIG. 4 shows a package sealed with the molded lid 5 shown in FIG. 3, and in the figure, 10 indicates the container body, and 11 indicates the contents such as alcohol. The reduced pressure absorbing convex portion 8 is pulled into the container and becomes substantially flat as the contents 11 filled in the container body 10 in a hot state cool down and the pressure inside the container is reduced.

FIG. 5 shows the package shown in FIG. 4 in an unsealed state.

When the opening tab 9 is pulled upward, the polyethylene-polypropylene blend polymer film 4 is released.
cohesive failure occurs, and the container body 10 can be easily opened without causing any stringiness or fuzzing on the flange surface.

As detailed above, according to the lid material of the present invention,
Not only can it provide a lid material that can be easily opened with appropriate peel strength without causing stringiness or fuzzing on the flange surface of the container body, but also
The thickness of the lid material is such that the heat of the seal bar can be sufficiently transmitted to the sealing surface through the lid material, so it is possible to provide a lid material that does not cause sealing defects, and also has a low heat seal layer. It is made of a polyethylene-polypropylene blend polymer film that does not contain any molecular weight substances, and has the advantage of being suitable for packaging alcoholic beverages because it has little odor.

Next, the present invention will be specifically explained with reference to examples.

Examples Polybutylene terephthalate film 50μ, polyvinylidene chloride coated unstretched nylon 30μ, unstretched polypropylene 50μ, polyethylene-polypropylene blend polymer (polypropylene;
50wt% random copolymer, density 0.90, MI=60,
Polyethylene; density 0.97, MI=8) film
30 μm were laminated in this order using an isocyanate adhesive, and the laminated material was vacuum formed to form a drop lid. This lid was then heat-sealed at 240°C to a polypropylene container filled with sake at 70°C.

After cooling, there is no abnormality in the lid, and the lid can be opened in good condition.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of an example of the lid material of the present invention, Figure 2 is a cross-sectional view of another example of the lid material of the present invention, and Figure 3 is an example of a molded lid using the lid material of the present invention. cross-sectional view, 4th
The figure is a cross-sectional view of the package sealed with the molded lid shown in FIG. 3, and FIG. 5 is a cross-sectional view showing the package shown in FIG. 4 in an unsealed state. 1...Polybutylene terephthalate film, 2
...Polyvinylidene chloride coated unstretched nylon film, 3...Unstretched polypropylene film, 4...
Polyethylene-polypropylene blend polymer film.

Claims (1)

[Claims for Utility Model Registration] (1) Consists of a polybutylene terephthalate film as the top layer, a polyvinylidene chloride coated unstretched nylon film and an unstretched polypropylene film as the middle layer, and a polyethylene-polypropylene blend polymer film as the bottom layer. A lid material characterized by: (2) Thickness of polycarbonate film is 30~
The thickness of the polyvinylidene chloride coated unstretched nylon film is 20 to 50μ,
The thickness of unstretched polypropylene film is 20~
100μ, and the thickness of the polyethylene-polypropylene blend polymer film is 10 to 100μ.
The lid material according to claim 1 of the utility model registration claim, characterized in that: