JPH057165Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a lid material for a container, particularly a lid material for a container subjected to hot water treatment.

Lid materials for disposable containers containing jelly, pudding, etc. are required to have light-shielding properties, and in order to have a beautiful appearance, laminates with aluminum foil as part of the structure are often used. ing.

However, when filled with the contents as above,
When the container is treated with hot water to sterilize it by boiling, the above-mentioned lid material has the disadvantage that wrinkles that have formed will remain due to the shape-retaining properties of aluminum foil, making it impossible to obtain a firm appearance. There is.

The purpose of this invention is to eliminate the above-mentioned drawbacks, to provide a lid material that does not wrinkle even when treated with hot water, and has excellent light-shielding properties and metallic luster.

In order to achieve the above purpose, in this invention, a sealant layer is provided on one side of a base material made of a biaxially stretched synthetic resin film that has a hot water shrinkage rate of 2 to 30% when treated at 65 to 95°C for 30 minutes. On the other side, a metal vapor-deposited layer and a biaxially stretched synthetic resin film having the same hot water shrinkage rate as above were laminated, and this was used as a lid material.

Here, the hot water shrinkage rate is 65 to 95
The degree of linear shrinkage of the film when immersed in heated water at ℃ for 30 minutes was measured in the vertical and horizontal directions and expressed as the average value.

Even after hot water treatment, the base material and the biaxially stretched film on the outer surface of this type of lid material have almost the same shrinkage rate, and the metal vapor deposited layer does not have shape retention, so even after treatment, No wrinkles, tight tension, metallic luster,
It also has excellent light blocking properties.

Embodiments of this invention will be described below with reference to the accompanying drawings.

As shown in FIG. 1, the lid material 1 includes a metal vapor deposited film, that is, a film in which an aluminum vapor deposited layer 4 is provided on a base material 2 via an anchor coat 3, and a film 6 in which a printed layer 5 is provided on the back surface. The base material 2 is bonded with an adhesive 7, and a sealant layer 8 is further provided on the outer surface of the base material 2.

The base material 2 is made of a synthetic resin film such as biaxially oriented nylon, biaxially oriented polypropylene, or biaxially oriented polyester, and has a shrinkage rate of 2 to 30% after hot water treatment at 65 to 95°C for 30 minutes. select. If the shrinkage rate is less than 2%, a product with sufficient tension cannot be obtained, and if it exceeds 30%, the container will be deformed and the commercial value will be significantly impaired.

The vapor deposited layer 4 is preferably made of aluminum, but may be made of other metals.

Further, the film 6 of the other surface layer is a synthetic resin film such as biaxially stretched nylon, biaxially stretched polypropylene, biaxially stretched polyester, etc.
Select from those having a shrinkage rate of 2 to 30% in hot water treatment at ℃. The reason for limiting the shrinkage rate is the same as in the case of base material 2.

The printed layer 5 provided on the back surface of the film 6 is provided in order to make the vapor deposited layer on the heat-sealed portion, which becomes white due to hot water treatment, less noticeable. Therefore,
The printed layer 5 may be provided only on the heat-sealed portion 9 shown by the broken line in FIG. 2, but it may of course be provided on the entire surface. Note that the figure shows a state in which the lid 10 is formed by punching out the lid material 1. In the figure, 11 is a tab.

The sealant layer 8 for heat-sealing the lid 10 to the container body is appropriately selected depending on the material of the container body. Moreover, this sealant layer 8 or adhesive 7
Alternatively, an inorganic pigment may be mixed into the anchor coat 3 to improve light-shielding properties.

More detailed examples will be given below.

[Example 1] Currently, the hot water shrinkage rate is 8% and the thickness at 75℃ for 30 minutes.
Prepare a 15 μ biaxially stretched nylon film with white ring-shaped printing applied only to the seal area.
In addition to this, the hot water shrinkage rate is 3% at 75℃ for 30 minutes, and the thickness
An 8μ biaxially stretched polypropylene film is coated with a urethane-based anchor coat, and a vapor-deposited film with a 400Å thick aluminum vapor-deposited layer is pasted with a urethane-based adhesive, with the printed layer and vapor-deposited layer facing each other, and then the polypropylene film is bonded with a urethane adhesive. 35μ on the outer surface of
A modified polyolefin sealant layer was provided with a thickness of .

Next, fill the polypropylene container with water,
Heat-seal the lid with the above configuration and store it at 85℃ for 30 minutes.
After boiling for several minutes, the lid was cooled and returned to room temperature, and the lid was taut and had a good appearance without wrinkles.

[Example 2] Instead of the biaxially stretched nylon used in Example 1,
High shrinkage nylon film 15μ (hot water shrinkage rate 15%)
A product with an excellent appearance equivalent to that of Example 1 was obtained in the same manner as in Example 1 except that .

[Comparative example]

The procedure was exactly the same as in Example except that a 10μ biaxially oriented polyethylene terephthalate film with a hot water shrinkage rate of only 0.1% at 95°C for 30 minutes was used as the base material and synthetic resin film, but wrinkles occurred and the appearance was poor. I didn't like it at all.

According to this invention, as described above, since the metal-deposited film and the film having a specific hot water shrinkage rate are bonded together, wrinkles do not occur even when sterilized by boiling, and the film has a taut appearance. It also has advantages such as excellent light-shielding properties and metallic luster.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a lid material showing an embodiment of this invention, and FIG. 2 is a plan view showing an example of the lid material formed into a lid. In the figure, 1 is a lid material, 2 is a base material, 3 is an anchor coat, 4 is a vapor deposition layer, 5 is a printing layer, 6 is a synthetic resin film, 7 is an adhesive layer, and 8 is a sealant layer.

Claims (1)

[Scope of utility model registration request] A sealant layer is provided on one side of a base material made of a biaxially stretched synthetic resin film with a hot water shrinkage rate of 2 to 30% in 30 minutes at 65 to 95°C, and a metal vapor deposition layer is sequentially applied to the other side, which is approximately the same as the base material. A container lid material made of laminated biaxially stretched synthetic resin films having similar hot water shrinkage rates.