JPS60172631A - Sealing tapes and method of sealing container - 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 The present invention relates to a sealing adhesive tape and an adhesive label (hereinafter referred to as sealing tapes) having a novel configuration, and a method for sealing a storage container using the sealing tape. Alternatively, sealing tapes are obtained by forming a printed display layer on a support made of a translucent plastic film and further applying a photocurable pressure-sensitive adhesive thereon, and affixing the tapes to a storage container. This relates to a method of sealing storage containers and containers characterized by irradiating light onto the area, the purpose of which is to be able to easily determine whether the seal has been opened, and once the seal has been opened. It is an object of the present invention to provide novel sealing tapes and a sealing method for preventing tampering, which are almost impossible to restore by pasting again.

As is well known, sealing tapes for bags and boxes (mainly paper boxes) are generally made by coating a pressure-sensitive adhesive on a support (base material) of plastic film such as cellophane, vinyl chloride, polyester, acetate, or polyolefin. So-called adhesive tapes have been used, but adhesive tapes can be removed gradually or by wetting with water or heating without damaging the container, so even if the container is opened, The drawback is that it is relatively easy to repair, but it is difficult to detect tampering. The drawback of clumping is the biggest drawback when used as a storage container for medicines, which means that it is not easy to tell if the contents have been removed or replaced.

For this reason, various proposals have not been made in the past as measures to prevent unauthorized opening. For example, there are adhesive tapes that use a fragile film as a support so that the tape itself is destroyed when the package is opened. When a pressure-sensitive adhesive is applied to the surface to create an adhesive label, when the seal is opened, the entire surface or part of the printed layer peels off from the support film, making it impossible to return to its original state or reuse it. It is something that is made to be. However, these known sealing tapes have problems with the internal strength of the support film, printed layer, pressure-sensitive adhesive, etc., the support film and the printed layer, the printed layer and the pressure-sensitive adhesive, the pressure-sensitive adhesive and the adherend ( The function is achieved by maintaining a balance of adhesive strength between storage containers), etc., but in practice it is difficult to maintain a good balance of adhesive strength between them. Additionally, in some cases, adhesive tape is pasted on top of these sealing tapes to reinforce it before opening the package. The above-mentioned known sealing tapes cannot be an effective preventive measure.

Originally, normal pressure-sensitive adhesives are adhesives that can be peeled off without leaving any adhesive residue on the surface to which they are applied, and that retain their binding properties semi-permanently. As described above, sealing tapes using pressure-sensitive adhesives can be removed relatively easily without leaving any traces, so sealing tapes using this pressure-sensitive adhesive are sufficient as a preventive measure against tampering. It's not a thing. In addition to pressure-sensitive adhesives, labels using water-activated adhesives or heat-activated adhesives are also known, but these adhesives can also be wetted with water or heated. By doing so, the label and adherend can be peeled off without damaging them.
Same as above, it is not preferable.

Against this background, the present inventors have developed sealing tapes that can prevent unauthorized tampering, that is, even if they can be peeled off without using a knife, scissors, etc., once peeled (opened),
As a result of various research, we have developed this book in order to provide a method for sealing tapes and storage containers that can easily be seen to have been opened in cases where the adherend and/or tape is damaged and difficult to reapply. The invention was completed.

That is, the present invention is characterized in that a transparent or translucent plastic film coated with a photocurable pressure-sensitive adhesive is used for sealing storage containers for pharmaceuticals, etc. The adhesive is cured to increase its cohesive force and adhesive strength, and if it is subsequently peeled off, the storage container and/or the tape will not only be destroyed, but will also be unable to be reapplied. The present invention relates to sealing tapes and sealing methods whose adhesive properties are reduced to such an extent that the adhesiveness of the tapes is reduced to such an extent that the adhesive properties of the sealing tapes are reduced to such an extent that the adhesiveness of the sealing tapes is reduced to such an extent that the adhesive properties of the sealing tapes are reduced to such an extent that the adhesive properties of the sealing tapes are reduced to such an extent that the adhesiveness of the sealing tapes is reduced to such an extent that the adhesive properties of the sealing tapes are reduced to such an extent that the adhesive properties of the sealing tapes are reduced to such an extent that the adhesiveness of the sealing tapes is reduced to such an extent that the adhesive properties of the sealing tapes are reduced to such an extent that the adhesive properties of the sealing tapes are reduced to such an extent that the adhesiveness of the sealing tapes is reduced to such an extent that the adhesiveness of the sealing tapes is reduced to such an extent that the adhesiveness of the sealing tapes is reduced to a degree.

The basic configuration of the present invention will be explained below.

When the sealing tape of the present invention is a label type, as illustrated in FIG. 1, a printed display M2 is formed on one side of a support 1 made of a transparent or translucent plastic film, A photocurable pressure-sensitive adhesive 3 is applied on the surface of the adhesive 2, and the adhesive 3 portion is covered with a release paper 4. In addition, when the tapes of the present invention are adhesive tapes with continuous long sides, a release treatment layer 5 is formed on one side of the support 1, as illustrated in FIG. There is a printed display layer 2 on one side as in the case of label type.
Then, a photocurable pressure sensitive adhesive layer 3 is formed to complete the process.

Note that the release paper 4 and the release treatment layer 5 are not essential components of the present invention. The support 1 is a transparent or translucent plastic film that does not easily absorb ultraviolet rays, such as polyvinyl chloride, polyester, polyolefin, etc.
It is selected from cellulose acetate, cellophane, etc. and used. The printed display layer 2 is formed by a gravure printing method, but the printing ink used is related to the state of destruction (destruction mode) when the tape is peeled off. The adhesive strength to the support 1, the cohesive force, the adhesive strength with the photocurable pressure-sensitive adhesive 3, etc. are adjusted so that the printed display layer 2 remains in the storage container 7 (FIG. 4). Selected with consideration. Furthermore, it goes without saying that the printing ink must not swell, dissolve, etc. when it comes into contact with the photocurable pressure-sensitive adhesive 3.

Next, there are two types of photocurable pressure-sensitive adhesives: one is a photo-reactive polymer as the main component of the pressure-sensitive adhesive, and the other is a combination of ordinary pressure-sensitive adhesives and low-molecular compounds such as photosensitive monomers and oligomers. Obtained by compounding system.

The former involves introducing unsaturated bonds into the copolymer by reacting glycidyl methacrylate with a system in which acrylic acid and methacrylic acid coexist in a copolymer of acrylic ester or methacrylic ester having 2 to 8 carbon atoms. This makes it a photo-curable pressure-sensitive adhesive. The latter method is based on rubber-based adhesives containing terpene resins or rosin derivatives as tackifiers such as natural rubber, synthetic rubber, etc., which are used in ordinary adhesive tapes (or labels), and rubber-based adhesives with carbon numbers of 2 to 8. An acrylic pressure-sensitive adhesive, which is a copolymer mainly composed of acrylic acid or methacrylic acid ester, is used as the base. That is, 5 to 50% (w/w, the same hereinafter) of a photosensitive monomer or olicomer is blended into the pressure-sensitive adhesive, and a photosensitizer is further added to induce a reaction. Photosensitive monomers include those containing two or more unsaturated bonds in the molecule, such as polyfunctional monomers such as 1,4-butanediol diacrylate, diethylene glycol diacrylate, and trimethylolpropane triacrylate, and epoxy acrylates. There are light (ultraviolet) curable polymers. Organic carbonyl compounds such as diacetyl, benzyl, benzophenone, benzoquinone, benzoin, and anthraquinone are used as sensitizers. The appropriate amount of the photosensitizer added is about 0.1 to 5% based on the photosensitive monomer.

The tapes of the present invention are obtained by applying the pressure-sensitive adhesive blended as described above to the surface of the support 1 facing the printed display layer 2 using a roll coater in the same manner as for obtaining ordinary adhesive tapes.

To seal the storage container 7 with the ml tape of the present invention, after applying the tape to a predetermined location of the storage container 7, a high-pressure mercury lamp is used to emit light from the surface of the support 1 at a wavelength of 20 nm.
Irradiation with ultraviolet rays of 0 to 400 nm for 1 to 10 seconds is sufficient. By doing this, the adhesive 3 is sufficiently cured,
The sealing of the storage container 7 is completed. The degree of curing of this photocurable pressure-sensitive adhesive varies depending on the type and amount of photoreactive functional groups contained in the adhesive, but in order to prevent the tape from being reapplied once removed, It is necessary to reduce the adhesive strength after curing to about 1/10 of the adhesive strength before curing.

Incidentally, the difference in the surface condition of the storage container with respect to the adhesive strength of the tapes of the present invention is practically negligible. That is, according to experiments conducted by the present inventors, the same type of tape of the present invention was applied to several types of storage containers each having a surface treatment using a vinyl chloride-vinyl acetate copolymer system and had a different surface condition, and the tape of the present invention was photocured. As a result of comparing the adhesive strength after 180'' peel strength was 1000 g in all cases.
/15 mm or more, and in both cases, a part of the storage container and a part of the tape (print display layer) were damaged and could not be reattached.

As detailed above, according to the sealing tapes and the sealing method of the present invention, once the seal is opened after being sealed, the sealing tape and/or a part of the storage container will inevitably be damaged beyond repair, and the tape itself will be damaged. Since the label cannot be reattached, the fact that the package has been opened can be easily recognized. Therefore, the present invention provides an extremely effective means to prevent so-called tampering.

The present invention will be specifically explained below using examples.

Example 100 parts of an acrylic copolymer (trade name SK Dyne 906 manufactured by Soken Chemical Co., Ltd.), 24 parts of bisphenol type epoxy acrylate resin, and 1 part of benzophenone were added to 100 parts of toluene on a 38μ transparent polyester film on which a printed layer was formed by gravure printing. Apply the dissolved pressure-sensitive adhesive to the area using a coater so that the amount of solid content is 25μ, and
It was dried at 00°C for 5 minutes to produce an adhesive tape.

This adhesive tape was attached to a storage container coated with UV varnish at room temperature. The adhesive strength at this time is 750 g/
It was 15 mm. (The test conditions were a peeling speed of 50 mm/
min, 180' peeling, or less. ) After 10 minutes, ultraviolet rays were irradiated for 6 seconds from a distance of 100 strokes using an IKw high-pressure mercury lamp to cure the adhesive. The adhesive strength at that time was 1,500g/15mm, and when the tape was subsequently peeled off, part of the surface of the storage container was destroyed, and part of the printed layer was transferred to the storage container as shown in Figure 4. .

As a comparative example, an adhesive tape using a bisphenol A-type epoxy acrylate resin and a pressure-sensitive adhesive that does not contain benzophenone has an adhesive strength of 700 g/
15mm, adhesive strength after irradiation is 780g/15mm
It was possible to remove the tape without damaging the storage container or the tape. A comparison of these adhesive tapes is shown in the table below.

(Margin below) In the Example product, the surface of the storage container and the adhesive tape were destroyed when peeled, whereas in the Comparative Example, there was no abnormality in the storage container and the tape.

As described above, the sealing tapes of the present invention, which are made by coating a transparent plastic film with a pressure-sensitive adhesive that cures with light (ultraviolet light), can be applied to storage containers such as pharmaceuticals, and then irradiated with light. The adhesive strength was so strong that the printed layer of the tape and the surface of the storage container were destroyed. In addition, the adhesiveness almost disappeared and it became impossible to reapply, making it possible to obtain sealing tapes that cannot be reapplied, which is the object of the present invention.

[Brief explanation of the drawing]

Fig. 1 is an enlarged cross-sectional view showing the basic structure of the sealing tape according to the present invention, Fig. 2 is an enlarged cross-sectional view showing another embodiment of the present invention, and Fig. 3 is a storage using the sealing tape according to the present invention. FIG. 4 is a perspective view showing the sealed state of the container, and FIG. 4 is a perspective view showing the storage container in an unsealed state after being sealed. 1: Support 2: Print display layer 3: Photocurable pressure sensitive adhesive 4: Release paper 5: Release treatment layer 6: Sealing tape 7: Storage container

Claims (2)

[Claims] (1) Sealing tapes comprising a printed display layer formed on a support made of a transparent or translucent plastic film, and a photocurable pressure-sensitive adhesive applied thereon. (2) After forming a printed display layer on a support made of transparent or translucent plastic film and applying a photo-curable pressure-sensitive adhesive thereon, a sealing tape is applied to the storage container. A method for sealing a storage container, characterized by irradiating the part with light.