JPH11190971A - Member and method for crime prevention - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make whether or not unsealing is done more easily detectable by visual sensation and securely while making good use of the easy sealing workability of an adhesive tape. SOLUTION: The crime-preventing member has an adhesive layer 3 on one surface of a transparent film 1 which has a phase difference by stretching it while interposing a reflecting layer 2 or making the layer 3 function as a reflecting layer and when the member adhered to an object through the adhesive layer 3 is peeled, the transparent film 1 is stretched. By this method whether or not the transparent film 1 is stretched or the presence/absence of the sealed ruin is detected by color by viewing the crime-preventing member adhered to the object through the adhesive layer 3 through a polarizing plate 5. The crime-preventing member can easily be adhered to the object for sealing, changes of the crime-preventing member can be detected by viewing the stretched part of the transparent film 1 is a discolored part through the polarizing plate 5, and it can easily be decided whether or not unsealing has been done with high precision.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crime prevention member and a crime prevention method in which a difference in phase difference is visualized as a discolored portion via a polarizing plate and visually recognized.

[0002]

BACKGROUND OF THE INVENTION In sealing an envelope or a medicine bottle via an adhesive tape, even if the adhesive tape is peeled off, the seal is unsealed, the documents in the envelope are stolen, or the medicine in the bottle is removed or replaced, the adhesive tape is not used. By re-adhering and sealing, it can be relatively easily restored to a state that is hardly different from the original state, so that there is a problem that the security property or the confirmation of opening / closing is poor. Therefore, various members for the purpose of crime prevention have been proposed, but there are difficulties in the reliability of determination of the presence or absence of opening and mass productivity, etc., and the condition has not been satisfied (Japanese Patent Laid-Open No. 63-106).
780, Japanese Utility Model Publication No. 63-47883, Japanese Utility Model Publication No. 3-53241, Japanese Utility Model Application Laid-Open No. 2-16969).

[0003]

SUMMARY OF THE INVENTION The present invention relates to a security member and a security method capable of easily and reliably visually detecting whether or not opening has been performed while utilizing the simple sealing work of an adhesive tape. For development purposes.

[0004]

According to the present invention, there is provided a transparent film having a phase difference which is different from that of a transparent film by stretching and having an adhesive layer via a reflective layer or serving also as a reflective layer, and adhered to an adherend via the adhesive layer. A security member, characterized in that the transparent film is stretched when peeled off, and the security member adhered to the adherend via an adhesive layer of the security member is visually recognized via a polarizing plate, and is transparent. It is an object of the present invention to provide a crime prevention method characterized by detecting the presence or absence of a film stretching or imprint by a color.

[0005]

According to the present invention, the security member can be easily adhered and sealed to the adherend via the adhesive layer, and when it is peeled off from the adherend, the transparent film is stretched at the time of peeling, and the film is removed. The phase difference changes due to the molecular orientation of the polymer to be formed, etc., and when viewed through the polarizing plate, the reflected light through the reflective layer interferes and the changed part of the phase difference is different from other parts It can be visualized as a discolored portion.

As a result of the above, the change of the security member can be visualized based on the color change due to the difference in phase difference, and the presence or absence of opening can be easily determined by visually detecting the change. Based on this, it is possible to easily visually recognize and make a highly accurate determination. Also, by providing a transparent seal mark as a hidden mark on the security member, the above-described stretching of the transparent film can be generated, and the authenticity of the security member is determined by checking the seal mark via a polarizing plate. It is possible to determine whether the security member has been replaced. Therefore, the presence or absence of opening can be checked without the need for special operation by a special device, and since it can be adhered in a dry state, it is excellent in handleability and can be efficiently attached to the adherend, and it has excellent manufacturing efficiency as a label and seal It can also be used.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The security member of the present invention has an adhesive layer via a reflective layer or also as a reflective layer on one side of a transparent film having a different phase difference by stretching, and is applied to an adherend via the adhesive layer. The transparent film is stretched when the adhered material is peeled off. Examples thereof are shown in FIGS. 1 (a) and 2. 1 is a transparent film, 2 is a reflective layer, 3 is an adhesive layer, and 31 is an adhesive layer also serving as a reflective layer.

As is apparent from the example of FIG. 1B, when the transparent film of the security member is stretched and a phase difference is generated, the region 11 is visually recognized through the polarizing plate 5 to change the color. Can be visualized as a part. In addition, when there is no polarizing plate, the difference in the phase difference cannot be recognized, and in a usual case, visual recognition is difficult.

[0009] The transparent film can be formed of an appropriate plastic in which a difference in retardation is generated by stretching. Transparent film that can be preferably used from the viewpoint of determination accuracy, etc., is excellent in stretchability, even if the adhesive force of the adhesive layer is weak, the trace of the stretch remains, and those having a large phase difference due to the stretch, especially, It shows good molecular orientation by stretching.

Examples of the plastic include olefin polymers such as polyethylene, polypropylene and ethylene-vinyl acetate copolymer, ester polymers such as polyethylene terephthalate and polyarylate, and chloride polymers such as polyvinyl chloride and polyvinylidene chloride. Examples include polymers, carbonate polymers, imide polymers, amide polymers and styrene polymers, sulfone polymers and ether sulfone polymers, vinyl alcohol polymers, cellulose acetate polymers, and acrylic polymers.

The transparent film may be made of a stretched film, but generally, a film having excellent isotropy is used for the purpose of increasing the difference in phase difference due to stretching. The thickness of the transparent film may be appropriately determined, but is generally 5 to 500 μm from the viewpoint of stretchability and the like.
m, especially 10 to 400 μm, especially 30 to 300 μm.

The reflection layer provided on one side of the transparent film or the adhesive layer serving also as a reflection layer reflects light transmitted through the transparent film in reverse to visualize a change in state of the transparent film as a discolored portion due to interference through a polarizing plate. The purpose is to do. In the case of an adhesive layer also serving as a reflective layer, the purpose is to adhere to an adherend via the adhesive layer.

For the above purpose, the reflection layer may be formed by an appropriate method. By the way, as an example, a metal powder is contained in a binder made of a resin or the like, and a reflective layer is formed by applying the metal powder to a transparent film, a vacuum deposition method, a sputtering method, and a metal thin film forming technique such as an ion plating method. Examples include a reflective layer obtained by attaching a vapor deposition layer or a metal foil to a transparent film.

On the other hand, examples of the pressure-sensitive adhesive layer which also functions as the reflection layer include those in which a metal powder is contained in the pressure-sensitive adhesive layer.
In the above, there is no particular limitation on the metal forming the powder, the vapor deposition layer and the foil, and those having excellent reflectivity are preferably used. In addition, white metals such as aluminum, stainless steel, zinc, tin, and silver can be preferably used from the viewpoint of the appearance of discolored portions of a transparent film via a polarizing plate, but non-white metals such as copper and iron. Can also be used.

The thickness of the reflective layer can be determined as appropriate, but in general, the thickness is preferably adjusted according to the strength of the coating layer, the vapor-deposited layer, the foil, etc., from the viewpoint of maintaining the stretchability of the transparent film. 0.5-500 μm, especially 1-300 μm, especially 3-1
The thickness is set to 00 μm. Note that the reflective layer or the adhesive layer also serving as the reflective layer may be formed using two or more kinds of metals.

The adhesive layer provided on one side of the transparent film with a reflective layer interposed therebetween is for the purpose of adhesion to an adherend and the like. The adhesive strength of the pressure-sensitive adhesive layer that also functions as the pressure-sensitive adhesive layer or the reflective layer is set to a size that allows the transparent film to be stretched when the object adhered to the adherend via the pressure-sensitive adhesive layer is peeled off. That is, the adhesive strength is set to cause permanent deformation of the transparent film when peeled off.

Therefore, the formation of the pressure-sensitive adhesive layer which also functions as the pressure-sensitive adhesive layer or the reflection layer is performed, for example, by using a transparent film such as a rubber-based pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive, a polyvinyl ether-based pressure-sensitive adhesive, or a hot melt pressure-sensitive adhesive. An appropriate tacky substance exhibiting an adhesive force according to the strength such as the strength can be used.

The formation of the pressure-sensitive adhesive layer which also functions as the pressure-sensitive adhesive layer or the reflection layer may be appropriately performed by a method of applying a pressure-sensitive adhesive or the like to the transparent film or the reflection layer, or a method of transferring the pressure-sensitive adhesive layer provided on the separator. It may be performed in a system. The thickness of the pressure-sensitive adhesive layer which also functions as the pressure-sensitive adhesive layer or the reflective layer can be determined as appropriate, but is generally 1
~ 500μm, especially 5 ~ 300μm, especially 10 ~ 150μ
m thickness.

As shown in FIGS. 1 and 2, the adhesive layer 3 or the adhesive layer 31 serving also as a reflective layer may be temporarily covered with the separator 4 for the purpose of preventing contamination and the like until practical use. preferable. The separator can be obtained, for example, as a thin film such as a plastic film or a laminate of paper and paper, which is subjected to a surface treatment with an appropriate release agent such as a silicone-based, long-chain acryl-based, or fluorine-based material, if necessary. By treating the exposed surface of the transparent film with the above-described release agent or the like instead of the separator, a security member that can be easily unwound as a wound body can be obtained.

In the security member according to the present invention, a reinforcing substrate 12 may be temporarily attached to the exposed surface of the transparent film 1 as illustrated in FIG. Such a reinforcing substrate is provided as necessary for the purpose of preventing the transparent film from being stretched before the security member is put into practical use. Therefore, as the reinforcing base material, an appropriate material such as a film, paper, nonwoven fabric, or a laminate thereof made of plastic exemplified by the above-mentioned transparent film can be used.

As shown in FIG. 3, the temporary attachment of the reinforcing base material is performed by treating the exposed surface of the transparent film 1 with a release agent or the like and bonding the reinforcing base material 12 provided with the adhesive layer 13 on the processed surface. Alternatively, it can be performed by an appropriate method such as a method using a hot-melt adhesive film as a reinforcing substrate.

When the transparent film is release-coated to achieve temporary adhesion, an appropriate method such as a method using a pressure-sensitive adhesive composed of the same kind of component as the release agent or a pressure-sensitive adhesive containing the component is used. It is more preferable to use a reinforcing base material having an adhesive layer that adheres well to the release coat from the viewpoint of the reinforcing effect and the like. The removal of the temporarily attached reinforcing base material can be performed at an appropriate stage such as when the security member is bonded to the adherend or after the bonding.

In the present invention, when the security member adhered to the adherend is to be peeled off, the transparent film needs to be stretched. Therefore, an appropriate means is provided to the security member so that the stretching is easily caused. be able to.
Incidentally, as an example, there is a method of forming the security member into a form in which stress concentration occurs partially.

The form in which the partial stress concentration occurs is as follows.
For example, the security member, particularly the form in which the thickness of the transparent film is partially thinned, the form in which the width is partially narrowed as illustrated in FIG. 4, the security member, particularly the transparent film, such as cuts or perforations, etc. It may be an appropriate one such as a form in which a defective portion is added.

Further, the security member according to the present invention may be provided with a transparent stamp mark by pressing a stamp such as a stamp on the transparent film as required. Even with such an imprint, the transparent film can be stretched and the imprint mark can be seen as a discolored portion via a polarizing plate, and when not passing through the polarizing plate, it is not easy to see because it is transparent, so it functions as a hidden mark Can be done. The hidden mark can be effectively used for determining the authenticity of the security member, such as whether or not the security member has been replaced.

That is, the security member may be provided with a visible mark formed by an appropriate method such as a printing method, which can be visually recognized even when the polarizing film is not interposed on the transparent film or the reflective layer. In this case, since the actual mark can be easily imitated, the reliability of the judgment of the security member using the actual mark becomes poor. On the other hand, when the hidden mark is used, since the imitation is difficult, the reliability as a criterion for authenticity determination is excellent. By making the hidden mark incapable of imitating easily, it is possible to perform authenticity determination with higher reliability.

In the security member of the present invention, as described above, when the security member is peeled off from the adherend, a difference in phase difference is caused by stretching the transparent film, and the difference is visually recognized as a discolored portion through the polarizing plate. It was made possible to visualize. The difference in the phase difference cannot be perceived by the naked eye, and therefore, there is a high probability that the peeled security member is re-adhered as unchanged, and replacement of the security member can also be detected by using a hidden mark consisting of an imprint mark together. . .

Therefore, the presence or absence of the security member can be easily determined by adhering the security member to the adherend via the adhesive layer and visually confirming via the polarizing plate, and providing a hidden mark consisting of a stamp mark. In such a case, the presence or absence of replacement of the security member can be easily determined based on the presence or absence. As a result, it can be preferably used as a security method comprising a simple detection system via a polarizing plate, and can easily convert visual / non-visual states depending on the presence or absence of a polarizing plate, and is excellent in simplicity of detection.

In the above, an appropriate polarizing plate can be used, and there is no particular limitation. In general, a film made of a hydrophilic polymer such as polyvinyl alcohol is stretched by treating with a dichroic dye such as iodine, or a film obtained by treating a plastic film such as polyvinyl chloride and orienting a polyene. Or a polarizing film protected by covering the polarizing film with a sealing film.

The security member according to the present invention can be used, for example, as a security tape or the like according to a conventional adhesive tape for sealing envelopes and boxes, sealing caps for chemical bottles and the like, and also for adhesives such as labels and seals. It can also be used for bonding to a sealed portion, and can be used for various purposes for detecting the presence or absence of opening or the like.

When bonding to an adherend, the tape may be formed into a suitable form such as a roll of security tape, a continuous body in which a plurality of labels and seals are temporarily attached to a long separator via the adhesive layer. Can be applied.

[0032]

EXAMPLE 1 A 30 μm thick reflective layer comprising a coating layer of a solution containing 100 parts by weight of aluminum powder per 100 parts by weight of low density polyethylene on one side of a transparent film of low density polyethylene having a thickness of 60 μm. And a 30 μm thick acrylic pressure-sensitive adhesive layer provided on a separator provided with a silicone-based release coat was transferred onto the reflective layer to obtain a security member.

The above security member was used as a security tape having a width of 10 mm, and an A4-size paper envelope containing an enclosure was sealed, and observed while changing the angle through a polarizing plate in this state, and no discolored portion was observed. Was.

Next, the security tape was carefully and gradually peeled off from the above-mentioned envelope while warming it. The paper envelope was opened, the enclosed matter was taken out, and sealed again using the peeled security tape. In this case, no change was observed in the security tape with the naked eye. Thereafter, the security tape for re-adhesion was observed through a polarizing plate while changing its angle. As a result, a discolored portion was observed in a small area. When the part was examined closely with the naked eye, elongation of the transparent film was observed.

In the above, the tensile strength required to give a permanent set to the transparent film (low-density polyethylene) in the security tape having a width of 10 mm was about 600 gf. On the other hand, when the security tape is adhered to the paper envelope via the adhesive layer and peeled 180 degrees, the adhesive strength is about 700 gf.
Met.

[Brief description of the drawings]

FIG. 1A is a cross-sectional view of an embodiment. FIG. 1B is a plan view illustrating visual recognition through a polarizing plate.

FIG. 2 is a sectional view of another embodiment.

FIG. 3 is a sectional view of still another embodiment.

FIG. 4 is an explanatory plan view of still another embodiment.

[Explanation of symbols]

1: transparent film (11: discolored area due to phase difference)
2: Reflective layer 3: Adhesive layer 31: Adhesive layer also serving as reflective layer 4: Separator 5: Polarizing plate

Claims (8)

[Claims] 1. A transparent film having a retardation different from that of a stretched film having an adhesive layer via a reflective layer or serving also as a reflective layer on one surface of the transparent film, and when the adhesive is adhered to an adherend via the adhesive layer, the adhesive is peeled off. A security member characterized in that the transparent film is stretched. 2. The security member according to claim 1, wherein the reflection layer or the pressure-sensitive adhesive layer serving also as the reflection layer comprises a metal powder-containing layer, a metal deposition layer, or a metal foil. 3. The security member according to claim 2, wherein the metal in the reflective layer or the adhesive layer serving also as the reflective layer is at least one of aluminum, copper, stainless steel, iron and zinc. 4. The security member according to claim 1, wherein the adhesive layer is temporarily covered with a separator, or the exposed surface of the transparent film is treated with a release agent. 5. The security member according to claim 1, wherein a reinforcing substrate is temporarily attached to an exposed surface of the transparent film. 6. The security member according to claim 1, wherein the security member is formed into a form in which stress concentration occurs partially. 7. The security member according to claim 1, wherein the transparent film has a transparent imprint. 8. The crime prevention member according to claim 1, which is adhered to an adherend via an adhesive layer of the crime prevention member, is visually recognized through a polarizing plate, and the presence or absence of stretching or imprinting of the transparent film is determined by color. A security method characterized by detecting.