JPS61206644A - Sealing sheet made of synthetic resin - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a synthetic resin sealing sheet that is adhered to the opening of a synthetic resin container to seal the opening. Part 2 relates to a synthetic resin sealing sheet that can be well adhered to the opening of a synthetic resin container by a heat seal adhesive means.

[Conventional technology]

In order to seal the opening of a synthetic resin container, the sealing sheet that is adhered to the opening is an aluminum sheet made by laminating aluminum foil with high gas repellency and a film made of synthetic resin material. There are synthetic resin sheets that are laminated and molded using only transparent synthetic resin materials so that the contents stored in the container can be directly viewed.

The means of adhering one of the two seal sheets, made of synthetic resin, to the opening of the container is ultrasonic adhesion.

There is also heat seal adhesion, which is performed using a heated pressure jig.

Ultrasonic bonding means uses heat generated by ultrasonic waves to generate heat at the contact area between the container opening and the sheet, but it is not possible to ensure that the container opening is sealed by the bonded sheet. In order to ensure that the container opening is in contact with the sheet, a dedicated rib for ultrasonic bonding must be integrally attached to the surface of the container opening that comes in contact with the sheet, surrounding the container opening. The problem was that the structure was complicated.

In contrast to this ultrasonic bonding method, the heat seal bonding method does not have the problem of having to attach a special structure for bonding around the opening of the container, and has no structural restrictions on the container. It has the advantage of being extremely simple to implement.

[Problem that the invention seeks to solve]

However, conventional synthetic resin type seal sheets do not have high heat resistance, so if the sheet is pressed against the opening of the container using a pressure jig heated to a high temperature and heat-bonded, the heat-bonding operation will affect the entire sheet. The heat from the pressing jig deforms the entire sheet, significantly deteriorating the appearance of the container as a product.

In particular, this type of transparent synthetic resin seal sheet not only seals the container, but also
Since the contents stored in the container can be visually recognized directly, the adhesive synthetic resin seal sheet forms an important part of the appearance of the container as a product. Therefore, the deformation of the synthetic resin seal sheet due to heating has become an extremely serious problem in appearance of containers as products.

The present invention was devised to solve the problems and inconveniences of the conventional examples mentioned above, and is aimed at providing a synthetic resin sealing sheet with excellent heat resistance.

[Means for solving problems]

Below are two synthetic resin seal sheets according to the present invention.

Embodiments of the present invention will be described with reference to the drawings.

The synthetic resin seal sheet 1-1 according to the present invention is a synthetic resin seal sheet that is heat-sealed and adhered to the opening of a synthetic resin type container to seal the opening 1, and constitutes the main part. An adhesive layer 2 is laminated on the lower surface of the main layer 3 molded from polyolefin resin, and polycarbonate 1.
It has a structure in which surface layers 5 made of resin are laminated.

The main layer 3 should be the main part of the seal sheet 1,
It exhibits the properties of Seal Sea 1-1 such as tensile strength, hardness, and softness, and becomes the main part.

The adhesive layer 2 is used to heat and bond the seal sheet 1 directly to the opening of the synthetic resin container, and its molding material is selected and set in accordance with the synthetic resin material for molding the container.

Bonding N4 uses a surface layer 5 made of polycarbonate resin, which is difficult to adhere to the main body N3 molded from polyolefin resin due to lack of solvent resistance, in order to firmly bond the main body N3 and the surface layer 5. It is firmly bonded to the main layer 3, thereby making the laminated structure of the sheet sealer strong.
゛The surface layer 5 is made of polycarbonate 1, which has excellent heat resistance, and is molded with resin, so even if a heated pressure jig comes into direct contact with it and heats it, it will not deform at all, and it will not deform at all before heating. It maintains its flat sheet shape.

Note that each layer is formed transparent.

[Effect]

Since the sealing sheet 1 according to the present invention has the structure as shown in "-," the adhesive layer 2 is pressed against the pressure jig heated to a desired temperature while the adhesive layer 2 is in contact with the circumferential surface of the upper end surface of the opening of the container. ,
When the seal sheet 1 is pressed against the upper end surface of the container opening, the seal sheet 1. That is, the adhesive layer 2 is heated and melted, and the seal sheet 1 is tightly heat-sealed and bonded to the opening of the container by the heated and fused adhesive layer 2, thereby sealing the opening.

When the sheet seal 1 is adhered to the container opening by pressing the pressure jig, it is not only the adhesive layer 2 that is heated by the pressure jig, but also the surface layer that is in direct contact with the pressure jig. 5 as a matter of course.

The main layer 3 is also heated.

In this way, during the bonding operation of the seal sheet 1 using the pressure jig, the entire seal sheet 1 is heated, but it is the surface layer 5 that is in direct contact with the pressure jig that is heated to the highest temperature.
Needless to say, it is.

The surface layer 5 is heated to the highest temperature by the pressure jig 2, but since it is molded from polycarbonate resin with excellent heat resistance, there is no thermal deformation caused by this heating.゛C: No unauthorized deformation occurs due to heat-sealed adhesive strips.

Therefore, the sealing sheet 1 according to the present invention can be heat-sealed and bonded to the opening of a container without causing thermal deformation and maintaining a good appearance.

By the way, it goes without saying that the surface layer 5 that is in direct contact with the applied pressing jig is heated to the highest temperature, although the temperature is lower than that of the surface layer 5.

Since the main body layer 3 is also heated, this heating generates a force that tends to deform the main body N3.

Therefore, if the surface layer 5, which does not undergo any thermal deformation at all, does not have sufficient rigidity, the surface layer 5 will also be improperly deformed by the thermal deformation force generated in the main layer 3. The main layer 3 is required to have enough rigidity to suppress the thermal deformation force generated therein, and is required to function as an aggregate against thermal deformation.

It is desirable that the thickness of the surface layer 5 is set to a relatively large value so that it can function as an aggregate against thermal deformation.

〔Example〕

The thin layer structure of the seal sheet 1 according to the present invention shown in FIG. 1 shows the most basic structure of the present invention.
In the illustrated embodiment, the adhesive layer 2 is.

If the container to which the sealing sheet 1 is adhered is a polyethylene resin type, it may be an ethylene vinyl acetate resin or a vinyl acetate pot melt type. When the container is made of AS resin, it is preferable to mold it using Lasocarco-1, and the layer thickness thereof is about 25 μm.

The main layer 3 is made of polyethylene resin and has a thickness of 30 to 150 microns.

Bonding layer 4 (J) is molded from polyethylene terephthalate resin and has a layer thickness of 9 to 20 μm.

The surface layer 5 is made of polycarbonate resin and has a thickness of 50 to 150 μm.

The thickness is set to a value slightly larger than the layer thickness of the main layer 3.

Practical values of the thickness of each layer of the seal sheet 1 according to the present invention are as follows. The values are roughly the same as above.

If you want to adjust the overall hardness of the seal sheet 1,
This is achieved by changing the thickness of each layer, especially the thickness of the main layer 3 and the surface layer 5.

However, when changing the layer thickness, it is necessary to maintain the relationship that the layer thickness of the surface layer 5 is larger than the layer thickness of the main body N3.

Also, the subject N3 is... In addition to polyethylene resin, there are also stretched polypropylene resins, which are polyolefin resins. Polypropylene resin or the like can be used.

FIG. 2 shows a preferred example of the use of the seal sheet 1 according to the present invention, and shows a mouth barrel portion 10 of a synthetic resin tube container 9.
on the top surface of. A sealing sheet 6 formed by cutting a sealing sheet 1 according to the present invention into a predetermined shape is heat-sealed and bonded.

In FIG. 2, the sealing sheet 6 includes a sheet main body 7 formed into a circular shape with a dimension slightly larger than the planar outer shell line of the mouth tube portion 10, and an appropriate peripheral end portion of this seam I/main body 7. It consists of a knob piece 8 which is integrally molded and extends outward from the handle.

This sealing sheet 6 is placed on the upper end surface of the mouth part 10 in such a manner that the sheet main body 7 covers the entire upper end surface of the mouth part 10, and in this state is pressed by a pressurizing jig heated to a desired temperature. The entire upper surface is pressed for a short period of time, and by heating and applying pressure with this pressing jig, tight adhesion to the entire upper end surface of the mouth tube portion 10 of the sheet body 7 is achieved.

The sealing sheet 6 is heat-sealed and bonded to seal the mouth tube part 10. Because its entirety is transparent.

The user does not have to peel off this sealing sheet 6.

The contents inside the tube container 9 can be directly observed through the sealing sheet 6, and thereby the user can confirm whether the product is what he or she is looking for.

In addition, since unauthorized opening of the tube container 9 as a product can be clearly and easily determined from the presence or absence of the sealing sheet 6 or the adhesion state of the sealing sheet 6 to the spout 10, It is possible to enhance and ensure virginity.

When opening the tube container 9, the sealing seal 1-6 can be easily peeled off from the tube container 9 by pinching the tab 8 with your fingertips and pulling firmly in both directions. Opening of the tube container 9 can be achieved by.

In the above description, only the case where the seal sheet 1 according to the present invention is bonded to a container using a heat seal bonding means is explained; Needless to say, it may also be glued to.

〔Effect of the invention〕

As is clear from the above description, the seal sheet according to the present invention does not undergo any thermal deformation even when heated for adhesion to a container, has a good appearance after being adhered to a container, and has a relatively good appearance. It exhibits many excellent effects such as good peeling stability after adhesion due to its properties, stable sealing strength, and excellent content resistance.

[Brief explanation of drawings]

FIG. 1 is an enlarged sectional view showing the basic laminated structure of two synthetic resin seal sheets according to the present invention. FIG. 2 is a perspective view of essential parts when the synthetic resin sealing sheet according to the present invention is used as the sealing sheet 1 for a tube container. Explanation of symbols I: Seal sheet, 2: Adhesive layer, 3: Main layer. 4; bonding layer; 5; surface layer.

Claims (1)

[Claims] A synthetic resin sealing sheet that is heat-sealed and welded to an opening of a synthetic resin container to seal the opening,
An adhesive layer (2) is laminated on the lower surface of the main layer (3) molded from polyolefin resin constituting the main portion, and a bonding layer (4) molded from polyethylene terephthalate resin is laminated on the upper surface of the main layer (3). ) A synthetic resin sealing sheet constructed by laminating a surface layer (5) molded from polycarbonate resin through a layer (5).