JPH0885573A - Top seal film for container - Google Patents

Abstract

PURPOSE: To provide a container top seal film which has so great a hiding power as to avoid impairment to printing design and is free from surface irregu larity and which can be subjected to a sufficient heat sterilization or heat- pressure sterilization. CONSTITUTION: In a container top seal film comprising an outer film 2 consisting of the synthetic resin of polyamides having extensibility and light transmittability, a pattern printing layer 3 consisting of pictures, letters, etc., and a ground color printing layer 4 formed thereunder in that order and a seal film 7 attached to the underside of the ground color printing layer 4 to closely attach top seal film to the opening edge of a container, the ground color printing layer is composed of at least the two layers, upper and lower, of double printing and the ink mixed with metal power is used in the lower layer 4b of the ground color printing layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The top seal film for a container according to the present invention is used for sealing the opening of a food container.

[0002]

2. Description of the Related Art In the past, a top seal that seals the opening of a cup containing food such as fruit or jelly or a bottle containing soft drinks is laminated with aluminum foil or synthetic resin film. Film is used.

This top seal film has not only the function of sealing the container, but also the contents are displayed by the letters and pictures printed on the top seal film, and the design makes it distinguishable from other products. There is also a function.

Therefore, if the contents of the container can be seen through the top seal film, the pictures and characters printed on the top seal film may become unclear and the balance of the design may be lost. It is desirable to have a concealing power to hide the color and shape of the contents.

Further, since the consumer mainly identifies and selects the product by looking at the product from above, the top seal film does not have irregularities on its surface, and a beautiful product with tension has a higher commercial value.

[0006] Further, it is general that the food as a content is sealed in a container and then sterilized together with the container. For this sterilization, the container is a container in which the food is sealed in a water tank containing hot water of about 85 ° C. There is boil sterilization that heats and sterilizes for about 30 minutes, retort sterilization that heats and sterilizes by heating and pressurizing for 30 minutes by placing a sealed container of food in a pressure tank filled with high temperature steam of about 120 ° C. High protein foods such as beans, seafood and meat must be subjected to the latter retort sterilization.

Therefore, even if the top seal film is placed in hot water or high temperature steam subjected to these sterilization treatments, the hiding power of the contents and the appearance of the surface should not be impaired as described above.

3 and 4 show an example of a laminated structure of a conventional top seal film for a container. The top seal film 30 shown in FIG. 3 is obtained by providing a pattern printing layer 32 such as a picture or a character on the lower surface of a stretchable polyamide-based synthetic resin film 31, and further providing a ground color printing layer 33 on the lower surface thereof. .

Reference numeral 34 in the drawing is, for example, an anti-oxidation film, 35 is an easy-open film for adhering the top seal to a container (not shown), and 36 is an adhesive layer.

This top seal film is excellent in heat resistance, and since the polyamide synthetic resin film 31 shrinks due to heating during sterilization treatment, the top seal film is taut and there is no unevenness on the surface, but background color printing Since the layer 33 is only a very thin layer of about several μm, the color and shape of the contents can be seen through the surface, and the design balance of the pattern printing is lost.

It should be noted that if the proportion of the pigment component of the ink used in the ground color printing layer 33 is increased or the ink is applied thickly, the hiding power for the color and shape of the contents is improved, but on the other hand, the ground color is The problem that the cohesive force of the ink in the printing layer 33 is reduced, and when the top seal film is peeled from the container, the top seal film is separated into upper and lower two sheets in the ground color printing layer 33, and it cannot be removed cleanly from the container. There is.

There is also one using an aluminum foil film in place of the above-mentioned antioxidant film 34 of the top seal film. Since the top seal film using aluminum foil film does not deteriorate even when placed in hot water or high temperature steam, it is possible to sufficiently sterilize the food sealed in the container under heat and pressure. Since it is excellent and has sufficient hiding power, clear printing can be performed, but on the other hand, there is a drawback that the film is easily sagged and the appearance of the product is impaired.

The top seal film 40 shown in FIG.
A pattern printing layer 42 such as a picture or a letter is provided on the lower surface of the stretchable polyamide-based synthetic resin film 41, a ground color printing layer 43 is provided on the lower surface thereof, and an aluminum vapor deposition surface 44 is further formed on the lower surface thereof. A polyethylene terephthalate film 45 is adhered.

In the figure, reference numeral 46 is an easy open film, and 47 is an adhesive layer. In this top seal film, the polyamide-based synthetic resin film 41 shrinks by heating with hot water or high-temperature steam during sterilization, while the aluminum-deposited polyethylene terephthalate film 44 hardly shrinks, so that the film surface has irregularities. It looks bad.

Further, the aluminum vapor-deposited on the polyethylene terephthalate film 44 undergoes a chemical change due to hot water or high-temperature steam during sterilization treatment, and changes into aluminum hydroxide to become transparent, which reduces the light-shielding property and loses the hiding power. Besides, the anchoring agent for fixing the aluminum vapor-deposited surface 44 has low heat resistance, and the laminate strength is reduced by the heat during the sterilization treatment. Therefore, this top seal film should be subjected to boil sterilization at about 85 ° C. 12 at the best
Retort sterilization with 0 ° C high temperature high pressure steam cannot be performed.

[0016]

DISCLOSURE OF THE INVENTION The present invention has a concealing power that does not impair the print design on the top seal film, has no irregularities on the surface, and can perform sufficient heat sterilization and heat pressure sterilization. It is an object of the present invention to provide a top seal film for containers that can be used.

[0017]

A top seal film for a container according to the present invention is a pattern printing layer consisting of pictures and letters and a background color on the lower surface of an exterior film made of polyamide synthetic resin having stretchability and translucency. Providing print layers in order,
A top seal film for a container, further comprising a seal film for adhering the top seal film to the opening edge of the container on the lower surface of the container, wherein the background color printing layer is formed by overprinting at least two upper and lower layers, and An ink containing fine metal powder is used as the lower layer of the ground color printing layer.

[0018]

The top seal film seals the container by attaching the lowermost seal film in the top seal to the opening edge of the container by heat welding or the like. The hiding power of the lower layer of the ground color printing layer overprinted on the lower surface of the exterior film is markedly improved by the fine metal powder mixed in the ink, and the color of the fine metal powder itself is hidden by the upper layer of the print layer.

Therefore, the pattern printing such as pictures and characters appearing on the surface of the top seal appears clearly without the design balance being disturbed by the color and shape of the contents and the color of the metal fine powder.

Further, since the fine metal powder of the ground-color printing layer for concealing the color and shape of the contents is mixed in the ink, it does not come into direct contact with hot water or high-temperature steam at the time of sterilization treatment and undergoes a chemical change. It is hard to cause and can withstand heat sterilization such as boil sterilization and retort sterilization.

Further, by heating in the sterilization treatment after sealing the container, the stretchable polyamide synthetic resin film used for the exterior film is slightly shrunk so that the surface of the top seal film has no irregularities.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 shows a laminated structure of a top seal film according to the present invention. In the figure, reference numeral 1 is a top seal film, 2 is an exterior film made of a stretchable transparent polyamide synthetic resin, and Is provided with a pattern print layer 3 such as a picture or a character and a background color print layer 4 from the lower surface.

The ground color printing layer 4 is formed by overprinting the upper and lower two layers, the upper layer 4a is printed with an ink of the color to be displayed on the surface of the top seal film 1, and the lower layer 4b is an aluminum fine aluminum powder. Printed with white ink mixed with paste. The ink used for printing the ground color print layer 4 will be described in detail later.

An anti-oxidation film 5 made of polyvinyl alcohol resin is provided on the lower surface of the exterior film 2 provided with the pattern print layer 3 for characters and pictures and the background color print layer 4 with an adhesive layer 6
It is affixed with a, and the lower layer further has an easy-open film 7 made of polypropylene or polyethylene having a heat-welding property attached with an adhesive layer 6b. The easy-open film 7 is used to bring the top seal film 1 into close contact with the open end of the container by heat welding, and is easily peeled off from the open end of the container by pulling up the tab piece 1a of the top seal film 1. is there.

Next, the ink used for printing the background color printing layer 4 will be described. Pattern print layer 3 for pictures and letters
The ink used for printing the ground color printing layer 4 is a pigment mixed with a resin binder. The ink used for the lower layer 4b of the ground color printing layer 4 is mixed with aluminum paste. And the hiding power is improved.

In the top seal film of this embodiment, ink containing 40% of white pigment is used for the upper layer 4a,
5% aluminum paste is added to this ink on the lower layer 4b.
Uses mixed ink.

The proportion of the aluminum paste mixed in the ink of the lower layer 4b is preferably 3 to 10%, and if it is less than this proportion, the hiding power is insufficient, and if it exceeds this proportion, the hiding power is increased, but the aluminum paste is Since it is gray, this color appears on the surface of the top seal film, which not only makes the printing of pictures and characters 3 unclear, but also reduces the cohesive force of the ink layer, and the top seal film is separated from the top and bottom by two sheets. It cannot be separated from the container cleanly.

The pigment contained in the ink of the upper layer 4a is 40%.
The front and back are suitable, and when the proportion of the pigment is small, the color of the aluminum paste of the lower layer 4b is transmitted and the color appearing on the surface of the top seal film becomes dull, and when the proportion of the pigment is 50% or more, the cohesive force of the ink layer is increased. As described above, it becomes impossible to cleanly remove the top seal film from the container as in the case where the amount of the aluminum paste mixed is increased.

FIG. 2 shows the use state of the top seal film. The top seal film 1 is heat-welded to the upper surface of the outer peripheral flange 8a formed at the open end of the cup container 8 by the lowermost layer, the easy open film 7. There is.

A part of the outer periphery of the top seal film 1 is provided as a knob piece 1a so as to project from the flange 8a of the cup container 8. By pulling up the knob piece 1a, the top seal film 1 is peeled from the cup container 8. I am able to do it.

Although the antioxidant film 5 is provided between the exterior film 2 and the easy-open film 7 in the above embodiment, depending on the kind of food to be sealed, the antioxidant film 5 may be replaced by a breathable film or the like. Sometimes a film is used.

[0032]

Since the top seal film for containers of the present invention has the above-mentioned constitution, it can exert the following effects.

(A) Since the ground color printing layer is composed of two layers of upper and lower layers and the ink used for printing the lower layer is a mixture of fine metal powder, the color of the contents of the container and The shape is unlikely to appear on the surface of the top seal film, and it is possible to clearly represent the design such as a picture or a character printed on the top seal film.

(B) A polyamide synthetic resin film having stretchability is used as the exterior film on the surface, and the film shrinks due to heat during sterilization treatment, so that the surface of the top seal is not uneven.

(C) Since the fine metal powder mixed in the ink does not come into direct contact with hot water or high temperature steam during the heat sterilization treatment, it is unlikely to undergo a chemical change, and the fine metal powder becomes transparent so that the hiding power is reduced. It is possible to sufficiently perform heat sterilization such as boil sterilization and retort sterilization, and heat and pressure sterilization without any drawbacks.

[Brief description of drawings]

FIG. 1 is a sectional view showing a laminated structure of a top seal film according to the present invention.

FIG. 2 is a view showing a usage state of the top seal film according to the present invention.

FIG. 3 is a cross-sectional view showing a laminated structure of a conventional top seal film.

FIG. 4 is a cross-sectional view showing another example of a conventional top seal film.

[Explanation of symbols]

 1 Top Seal Film 2 Exterior Film 3 Pattern Printing Layer 4 Ground Color Printing Layer 4a Upper Layer 4b Lower Layer 5 Antioxidant Film 6a, 6b Adhesive Layer 7 Easy Open Film 8 Cup Container

Claims (1)

[Claims] 1. A pattern printing layer consisting of pictures and letters and a background color printing layer are sequentially provided on the lower surface of an exterior film made of polyamide synthetic resin having stretchability and translucency, and a top seal film is further provided on the lower surface thereof. A top seal film for a container, which comprises a seal film adhered to the opening edge of the container, wherein the ground color printing layer is formed by overprinting at least two upper and lower layers, and a metal is formed as a lower layer in the ground color printing layer. Top seal film for containers made from ink mixed with fine powder.