JP2000293108A - Forgery preventing label - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a forgery preventing label having a simple structure, difficult to peel from a body to which the label is stuck and not reusable for forgery, unsealing and tampering. SOLUTION: The forgery preventing label has a brittle substrate 1 and an adhesive layer containing a heat foaming agent. Heat expandable microcapsules 2 are preferably used as the heat foaming agent. The brittle substrate 1 comprises a synthetic resin containing a filler such as silica, calcium carbonate and titanium dioxide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-counterfeiting label for preventing reuse for forgery, opening and falsification.

[0002]

2. Description of the Related Art Various types of anti-counterfeit labels used for preventing forgery, opening and tampering have been proposed. For example, Japanese Patent Publication No. 49-3559
No. 6 discloses a forgery prevention label in which the visible symbol is destroyed when the attached label is peeled off. This label is composed of a self-supporting film, a mask and an adhesive layer, and when the self-supporting film is peeled off,
The mask portion is configured to remain attached to the adhesive layer so that the self-supporting film and the printed symbols applied to the mask are destructively separated. Japanese Patent No. 2598022 describes a forgery prevention label having a sticking evidence persistence in which a self-supporting film having been printed is provided with an adhesive layer containing a fluorescent dye. When this anti-counterfeit label is peeled off from the adherend, it is clear that the remaining fluorescent dye is peeled off because the remaining fluorescent dye emits light upon irradiation with ultraviolet rays. Japanese Utility Model Laid-Open No. 59-1077 discloses a reusable adhesive label having the structure shown in FIG. This label is a strong transparent plastic film 7
A release agent layer 8 is partially provided on one side of the substrate, and a vapor deposition film 9
Is formed, and the pressure-sensitive adhesive layer 10 and the release film are further laminated. When the peelable film is peeled off from the label and adhered to the adherend 5, if it is to be peeled from the adherend, as shown in FIG. Since the force is weaker than the other parts, the vapor-deposited film and the pressure-sensitive adhesive layer at the part where the release agent layer is provided remain on the adherend.

Recently, a so-called brittle label having a brittle film as a base material and provided with an adhesive layer thereon has been proposed and used. This label is difficult to peel because the base material is fragile.

[0004]

However, both the forgery prevention label and the reuse prevention label as proposed above have various problems.
For example, JP-B-49-35596 and JP-A-59-35596
The structure disclosed in Japanese Patent No. 1077 is complicated in structure, requires a plurality of manufacturing steps, makes the manufacturing complicated, and increases the cost. Further, the one described in Japanese Patent No. 2598022 requires ultraviolet irradiation to confirm that it has been peeled off, and can be easily removed with a cotton cloth or the like impregnated with a solvent. On the other hand, a so-called brittle label using a brittle base material solves these problems. When the label is to be peeled, the base material is cut off, and a part of the label is covered. It remains on the body, and the label trace cannot be easily removed. However, this fragile label is a dryer attached to an adherend in a dryer.
For example, there is a problem that the adhesive strength of the pressure-sensitive adhesive is reduced when the adhesive is heated, and the adhesive can be easily peeled off.

On the other hand, various adhesive tapes having an adhesive layer containing a thermal foaming agent on a substrate are known (for example,
JP-A-61-78887, JP-A-2-30587
No. 8, these adhesive tapes are intended to be easily peelable from an adherend, and are not intended to remain on the adherend for the purpose of preventing forgery.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above-mentioned conventional technology, and has been made to solve the above-mentioned problems in the forgery prevention label. That is, an object of the present invention is to provide a forgery prevention label that has a simple structure, is difficult to peel off from an adherend, and cannot be reused for forgery, opening, and falsification. .

[0007]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that when an adhesive layer in an adhesive tape having an adhesive layer containing a thermal foaming agent is combined with a brittle base material, a heating is performed. The present inventors have found that a forgery prevention label that is difficult to peel off can be obtained, and have completed the present invention.

The anti-counterfeiting label of the present invention is used to prevent re-use for forgery, opening and falsification. The anti-counterfeiting label comprises a brittle substrate and an adhesive containing a thermal foaming agent. And an agent layer. As the thermal foaming agent, heat-expandable microcapsules can be preferably used.

[0009]

FIG. 1 is a schematic sectional view of an example of a label for preventing forgery of the present invention. In the figure, 1 is a brittle substrate, 2 is a thermal foaming agent such as microcapsules, 3 is an adhesive, and 4 is a peelable film.

The brittle substrate in the present invention is in the form of a film composed of a synthetic resin containing a filler. In the present invention, the term "brittle" means that the anti-counterfeit label attached to the adherend is torn off when the label is peeled off, and the adhesive layer adheres to the adherend. Although it depends on the relationship with force, in general, room temperature (2
Elongation at 3 ° C.) is 0-20%, and the breaking strength is 3 kg /
mm ² or less, preferably elongation 0-10%, breaking strength is used to select from a range of 0~2kg / mm ^2.

Specifically, as the synthetic resin, a vinyl chloride resin, an acrylic resin, an acrylonitrile-butadiene copolymer resin, SBR or the like is used. As the filler, calcium carbonate, barium carbonate, barium sulfate,
Inorganic fillers such as kaolin, diatomaceous earth, titanium oxide, aluminum oxide, antimony trioxide, magnesium oxide, magnesium silicate, aluminum silicate, silica, talc, carbon black and the like;
Species or a combination of two or more can be used. These fillers are for imparting brittle properties to a film made of a synthetic resin, and the compounding amount thereof can be appropriately set depending on the degree of the brittleness, the type of the synthetic resin to be used, and the like. Although it is possible, it is generally preferable to add the compound in an amount of 50 to 500 parts by weight based on 100 parts by weight of the synthetic resin. Further, the thickness of the brittle substrate is appropriately set, but is generally preferably in the range of 25 to 100 μm.

The adhesive layer to be laminated on the brittle substrate is
The adhesive containing a thermal foaming agent, and as the adhesive, a pressure-sensitive adhesive exhibiting adhesiveness at ordinary temperature is preferable, and examples thereof include an acrylic adhesive and a rubber adhesive. In addition, depending on the purpose of use of the label, it is possible to use various adhesives, for example, a delayed tack-type adhesive that exhibits adhesiveness for a certain period of time by heating, a rewet adhesive, a cold-setting adhesive, A thermosetting adhesive or the like can also be used.

As the thermal foaming agent to be contained in the adhesive layer, any known thermal foaming agent which foams upon heating can be used. For example, organic foaming agents such as azobisisobutyronitrile, Inorganic foaming agents and the like can be used, but heat-expandable microcapsules are preferably used. The heat-expandable microcapsules are described in, for example,
It can be produced by the method described in Japanese Patent No. 26524, for example, in which a volatile substance or a substance which decomposes by heat to generate a gas is incorporated in the outer shell of a synthetic resin.

The volatile substance contained in the microcapsules includes, for example, butane, isobutane, pentane, neopentane, hexane and the like. The resin constituting the outer shell is methyl polyacrylate, polyethyl ethyl, acrylic Acrylic polymers such as acid ester-acrylonitrile copolymer, methacrylic acid ester-acrylic acid copolymer, vinylidene chloride polymers such as vinylidene chloride-acrylonitrile copolymer, vinylidene chloride-vinyl chloride copolymer, polystyrene, styrene- Examples include polystyrene-based polymers such as acrylate copolymers.

The average particle size of the heat-expandable microcapsules is as follows:
It is set in the range of 3 to 200 μm, preferably 5 to 100 μm. In addition, the thermal decomposition temperature of the heat-expandable microcapsules can be appropriately set depending on the use conditions of the label, but in order to keep the foam in a non-foamed state, the thermal expansion temperature may have a higher thermal decomposition temperature than the storage temperature of the adherend. For example, when the storage temperature is 50 ° C. or lower, a material that decomposes in the range of 70 ° C. to 200 ° C. to foam the adhesive layer is preferably used.

In the present invention, the heat-expandable microcapsules can be contained in the adhesive layer at an appropriate content, but generally contained in the range of 1 to 50% by weight based on the solid content of the adhesive layer. Is preferred. When the content of the heat-expandable microcapsules is less than 1% by weight, the intended purpose cannot be achieved due to insufficient foaming of the adhesive layer. Cannot be obtained.

The thickness of the adhesive layer is preferably in the range of 20 to 300 μm, especially 25 to 150 μm. The adhesive strength of the adhesive layer to the adherend is 180 ° peel strength (300 mm / min) measured at normal temperature (23 ° C.).
0.3 to 2 kg / 1 at the time when the brittle substrate breaks
It is preferably in the range of 0 mm.

If desired, a peelable protective film may be provided on the surface of the adhesive layer. As the peelable protective film, a known film such as a high quality paper or a synthetic resin film treated with a silicone release agent can be used.

The anti-counterfeit label of the present invention can be obtained, for example, by applying an adhesive containing a thermal foaming agent on a peelable protective film by an appropriate method to form an adhesive layer, and then forming a brittle group on the adhesive layer. The adhesive sheet can be manufactured by laminating a material to produce an adhesive sheet, for example, printing the surface of a brittle base material and cutting it into a predetermined shape.

The anti-counterfeit label of the present invention may be attached to an adherend which may be reused for counterfeiting, opening, and falsification. For example, it can be used by attaching it to packaging containers for medicines and foods, mails, IC packages, documents, books and the like. In that case, after sticking, you may heat above the foaming temperature of an adhesive layer. When the label of the present invention attached to the adherend is to be peeled off in a state where it is not heated, the adhesive layer is peeled off from the adherend because the substrate is brittle because the substrate is brittle. Remains without. Further, in the case of a conventional forgery prevention label using a brittle base material, it was possible to peel off the adherend by heating to reduce the cohesive force of the adhesive, but the present invention When the anti-counterfeit label is heated, the adhesive layer foams, and as a result, the base material is cut off, or the foamed adhesive remains on the adherend. FIG. 2 shows the latter case, in which the adhesive layer 3a foamed by heating splits,
This shows a state in which a part thereof remains on the adherend 5. Reference numeral 6 denotes printed ink. Therefore, forgery,
It can be prevented from being reused for opening and falsification.

[0021]

EXAMPLES Examples 1 to 6 As an adhesive, butyl acrylate-acrylic acid (10
0/8) 30% by weight solution of copolymer (solvent: toluene /
Ethyl acetate (4/6) mixture) (# 4331: Kuramoto Sangyo Co., Ltd.) was added to an isocyanate compound (Coronate L:
A mixture of 1% by weight (manufactured by Nippon Polyurethane Industry Co., Ltd.) was used, and the resulting mixture was used as microcapsules in EXPANCEL 461 (particle size: 9 to 16 μm (before heating),
μm (after heating), foaming temperature about 100 ° C .: manufactured by Nippon Philite Co., Ltd. and Expancel 092-120 (particle size: 28 to 38 μm (before heating), 120 μm (after heating), foaming temperature about 110 ° C .: Nippon Philite Co., Ltd.)
Were mixed in the mixing ratio shown in Table 1 below to prepare an adhesive composition.

The above adhesive composition was used as a peelable protective film as a high-quality paper (110 EP) treated with a silicone resin.
S (P): manufactured by Oji Paper Co., Ltd.) so that the film thickness after drying was 50 μm, and dried in an oven at 60 ° C. for 5 minutes to form an adhesive layer.

As a brittle substrate, a vinyl chloride film containing 180% by weight of calcium carbonate as a filler (film thickness: 60 μm, elongation: 20% (23 ° C.), breaking strength: 1.
Using 35 kg / mm ² (23 ° C., manufactured by Kuramoto Sangyo Co., Ltd.), this was laminated on the adhesive layer to prepare an adhesive sheet. A desired printing was performed on the adhesive sheet, and the sheet was cut into a width of 25 mm to prepare a sample.

Comparative Example 1 A sample was prepared in the same manner as in Example 1 except that microcapsules were not used.

The above sample was stuck on a SUS304 steel plate and pressed by a pressure roll under a pressure of 2 kg. For these samples, the room temperature adhesive strength and 6
The adhesive strength at 0 ° C. was measured to evaluate the peeling state of the sample.

(Normal Temperature Adhesive Strength) The sample adhered was allowed to stand in an atmosphere of 23 ° C. × 65% RH for 30 minutes, and then under the same conditions at a tensile speed of 300 mm / min.
The 80 ° peel strength was measured. Table 1 shows the results.

(Adhesive strength at 60 ° C.) The samples adhered to each other were heated at 100 ° C. for 1 minute in a hot air circulating thermostat and heated at 150 ° C. for 1 minute, respectively, at 60 ° C. × 30% RH. Under the atmosphere of 3
After leaving for 0 minutes, under that condition, pulling speed 300mm
The peel strength at 180 ° / min was measured. Table 1 shows the results. In addition, in Table 1, "film" means a brittle base material, and the value of peel strength shows the value at the time of film cutting or film peeling.

[0028]

[Table 1]

As is clear from the results shown in Table 1, when the anti-counterfeiting label of the present invention is peeled off from the adherend after being adhered, the brittle substrate is cut and cannot be peeled off. When the film is peeled off at 60 ° C. after heating, the foamed adhesive layer remains. On the other hand, in the case of Comparative Example 1, at 60 ° C., it can be seen that the adhesive layer and the film are all peeled off.

[0030]

Since the anti-counterfeiting label of the present invention has the above-mentioned constitution, it is difficult to peel it off after being attached to an adherend, and it can be reused for forgery, opening and falsification. Can not. That is, since the base material is brittle, when the label is to be peeled, the base material is broken and the adhesive layer remains without peeling from the adherend. Also, even if it is attempted to peel off by lowering the cohesive force of the adhesive by heating, since the adhesive contains a thermal foaming agent, the adhesive layer is foamed to form a foamed adhesive layer, As a result, a part of the foamed adhesive remains on the adherend. Therefore, the forgery prevention label of the present invention cannot be reused for forgery, opening, and falsification.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a label for preventing forgery of the present invention.

FIG. 2 is a diagram showing a state where the label of FIG. 1 is peeled off from an adherend after being heated.

FIG. 3 is a cross-sectional view of an example of a conventional reuse-preventive pressure-sensitive adhesive label, showing a state in which the label is peeled off from an adherend.

[Explanation of symbols]

1: brittle base material, 2: thermal foaming agent such as microcapsules,
3 adhesive, 3a foamed adhesive layer, 4 release film, 5 adherend, 6 ink, 7 transparent plastic film, 8 release agent layer, 9 deposited film, 10 adhesive layer.

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat 参考 (Reference) B42D 15/00 371 B42D 15/00 371 (72) Inventor Shinji Masiki 3-7-4 Higashiikebukuro, Toshima-ku, Tokyo No. Kuramoto Sangyo Co., Ltd. (72) Inventor Yoshiaki Ito 3-7-4 Higashi-Ikebukuro, Toshima-ku, Tokyo F-term (Reference) 2H113 AA06 BB02 BB22 CA39 DA49 DA53 DA64 EA22 EA24 FA04 FA10 FA32 4F100 AA08A AA20A AA21A AK01A AK15 AK25G AK51G AL05G AR00A AT00C BA02 BA03 BA07 BA10A BA10C BA31 CA01B CA23A CB05B DE04B DJ01B GB90 JK01A JK08A JL02 JL05 JL14 JL14C YY00A

Claims (5)

[Claims] An anti-counterfeit label comprising a brittle substrate and an adhesive layer containing a thermal foaming agent. 2. The forgery prevention label according to claim 1, wherein the thermal foaming agent is a heat-expandable microcapsule. 3. The content of the heat-expandable microcapsules is:
The anti-counterfeit label according to claim 2, wherein the solid content of the adhesive layer is 1 to 50% by weight. 4. The brittle substrate is made of a synthetic resin containing a filler, has an elongation at room temperature of 0 to 20%, and a breaking strength of 3.
counterfeit prevention label according to claim 1 and has a kg / mm ² or less. 5. The anti-counterfeit label according to claim 4, wherein the filler is at least one selected from silica, calcium carbonate and titanium oxide.