JPH1081085A - Tamper-resistant protection sheet and tamper-proof method - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a falsification prevention method capable of reliably and easily preventing display of a certificate or the like or change of contents such as containers. SOLUTION: An anti-tampering protection sheet comprising a support and an adhesive layer, wherein the self-adhesive force of the adhesive layers is 2 kg / 20 mm width or more, is used for articles such as certificates and containers. The display is provided on the adhesive layer, and the pressure-sensitive adhesive layers are attached to each other to cover the article, thereby preventing the display or the contents of the article from being changed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the use of characters or marks on identification documents,
Protection sheet for preventing falsification (falsification) and prevention of falsification to prevent changes such as changes in labeling of photos or photos, removal or replacement of contents in containers, boxes, etc. It is.

[0002]

2. Description of the Related Art Conventionally, as a method of preventing a change in the display shown on a certificate such as an identification card or a change in the contents contained in a container, the surface of the certificate, a sealing portion of the container, and the like are used. If an adhesive sheet is attached to the necessary part to prevent the above change, and this sheet is peeled off and the above change is made, traces of peeling will remain on this sheet, and as a result, There is a way to easily determine the change. Specifically, if the adhesive sheet is peeled, the support of this sheet may be damaged,
When the printed marking layer provided on a part of the surface of the pressure-sensitive adhesive layer is broken, traces of peeling are left on the sheet.

[0003]

However, in the above-mentioned method, when the adhesive sheet is peeled at a low speed, the adhesive sheet may be peeled off without leaving any trace of the peeling. I couldn't say that. Japanese Patent Publication No. 3-5319 proposes a method of overcoming the above problem by irradiating light after bonding using a photocurable pressure-sensitive adhesive, but light irradiation after bonding is a problem in workability. In addition, there are disadvantages such as the necessity of an expensive light irradiating device and the need to protect an operator from the irradiating light.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional circumstances, and in preventing the display of a certificate or the like or the contents of a container or the like from being changed, it is possible to reliably and easily prevent tampering without causing the above-mentioned adverse effects. It is intended to provide a way.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in order to achieve the above-mentioned object, and as a result, in preventing the display of certificates and the like and the change of contents such as containers, etc.
Using a specific self-adhesive adhesive sheet, providing it on articles such as the above-mentioned certificates and containers, and bonding the adhesive layers together to cover the article, thereby ensuring reliable and easy tampering The present inventors have found that a preventive effect can be obtained, and have completed the present invention.

That is, the present invention relates to a protective sheet for preventing the display or contents of articles such as certificates and containers from being changed, and comprises a support and an adhesive layer. A tamper-resistant protection sheet (claims 1 to 3), characterized in that the self-adhesive force between them is 2 kg / 20 mm width or more. In addition, the present invention, in preventing the display or change of the contents of goods such as certificates and containers,
According to a fourth aspect of the present invention, there is provided a tamper-proof method comprising providing a tamper-proof protective sheet having the above-mentioned configuration on an article, and covering the article by bonding together an adhesive layer.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The falsification-preventing protective sheet of the present invention comprises a support and a pressure-sensitive adhesive layer, and the self-adhesive force of this pressure-sensitive adhesive layer, that is, the adhesive force when the pressure-sensitive adhesive layers are bonded to each other. Is not less than 2 kg / 20 mm width, preferably not less than 3 kg / 20 mm width (usually up to 10 kg / 20 mm width). According to such a protective sheet, for example, if the protective sheet covers articles such as documents and containers and the adhesives are stuck together at the peripheral portion, the large self-adhesive force makes it easy to apply. It is difficult to peel off, and even if this is peeled off, by printing on the pressure-sensitive adhesive layer surface, since the collapse of the printing is remarkably seen, it was possible to easily determine the change of the display or the contents of the article, etc. Therefore, it is possible to reliably and easily prevent tampering.

The above-mentioned pressure-sensitive adhesive layer exhibiting such effects is represented by the following formula: (Wherein, R is a linear or branched hydrocarbon group having 2 to 20 carbon atoms, and n is a natural number of 2 or more) having a polycarbonate structure having a repeating unit represented by the following formula: -Is preferably composed of an adhesive composition containing-as a main component.

[0009] As the above polymer, polycarbonate
Polyester synthesized from todiol and dicarboxylic acid, polyester synthesized from polycarbonate dicarboxylic acid and diol, polyurethane synthesized from polycarbonate diol and diisocyanate, etc. No. Among these, as a polyester synthesized from polycarbonate-diol and dicarboxylic acid,
In particular, geo that required polycarbonate bone
Having a weight average molecular weight of 2 synthesized from a dicarboxylic acid component and a dicarboxylic acid component having a dicarboxylic acid having a molecular skeleton of an aliphatic or alicyclic hydrocarbon group having 2 to 20 carbon atoms.
Those having 10,000 or more, preferably 30,000 or more (usually up to 300,000) are preferably used.

The above polycarbonate diol has a number average molecular weight of 500 or more, preferably 800 or more. If the molecular weight is too low, the synthesized polyester will be too hard as a pressure-sensitive adhesive, will have insufficient tackiness, and it will be difficult to obtain good results in self-adhesion. Specific examples thereof include hexamethylene carbonate-diol, 3-methylpentenecarbonate-diol, propylene carbonate-diol, and mixtures and copolymers thereof. As a commercially available product, "PLACCE" (trade name, manufactured by Daicel Chemical Industries, Ltd.)
L CD208PL ”,“ CD210PL ”,“ C ”
D220PL "," CD208 "," CD21 "
0 ”,“ CD220 ”,“ CD208HL ”,“ CD ”
210HL "and" CD220HL ".

The diol component may be ethylene glycol, propylene glycol, butanediol, if necessary.
Linear diols such as diol, hexanediol, octanediol, decandiol, octadecandiol,
Alternatively, various branched diols and the like may be appropriately mixed and used. The use amount of these diols is 50% by weight or less, preferably 30% by weight or less based on the whole diol components. In order to increase the molecular weight of the synthesized polyester, a small amount of a trifunctional or higher polyol component can be added.

The dicarboxylic acid component has 2 to 2 carbon atoms.
It is a dicarboxylic acid having a molecular skeleton of 20 aliphatic or alicyclic hydrocarbon groups, and the above-mentioned hydrocarbon groups may be linear or branched. Specifically, succinic acid,
Methyl succinic acid, adipic acid, pimelicic acid, azelaic acid, sebacic acid, 1,12-dodecandioic acid, 1,14
-Tetradecandioic acid, an-hexyladipic acid, tetrahydrophthalic acid, endmethylenetetrahydrophthalic acid, and the like, and acid anhydrides and lower alkyl esters thereof.

The polyester is obtained by subjecting the above-mentioned diol component and dicarboxylic acid component to an esterification reaction according to a conventional method without using a catalyst or an appropriate catalyst. At this time, the diol component and the dicarboxylic acid component are desirably equimolarly reacted, but either of them may be used in excess to promote the esterification reaction. The polyester thus obtained preferably has the above-mentioned molecular weight. If the molecular weight is too low, the cohesive strength will be insufficient.

In the present invention, a polymer having a polycarbonate structure, such as polyester, is usually used.
Is subjected to a crosslinking treatment by an appropriate means to obtain a pressure-sensitive adhesive composition having excellent self-adhesiveness and heat resistance. The crosslinking treatment can be performed using a crosslinking agent such as a polyisocyanate compound, an epoxy compound, and an aziridine compound.
The crosslinking agents can be used alone or in a mixture of two or more. The amount to be used is appropriately selected depending on the balance with the polymer to be crosslinked, but is usually 0.5 to 100 parts by weight of the polymer.
It is preferred that the mixture be blended in an amount of 5 to 5 parts by weight and subjected to a crosslinking treatment.

[0015] Among the crosslinking agents, polyisocyanate compounds are particularly preferred. Specifically, lower aliphatic polyisocyanates such as ethylene diisocyanate, butylene diisocyanate, hexamethylene diisocyanate, cyclopentylene diisocyanate, cyclohexylene diisocyanate Alicyclic polyisocyanates such as isophorone diisocyanate, 2,4-tolylene diisocyanate, diphenylmethane diisocyanate,
Aromatic diisocyanates such as xylylene diisocyanate, and tolylene diisocyanate or hexamethylene diisocyanate adducts of trimethylolpropane, and the like.

As another crosslinking treatment, there is a method in which a polyfunctional monomer is blended with a polymer and this is crosslinked with an electron beam or the like. Polyfunctional monomers include polyethylene glycol di (meth) acrylate, pentaerythritol
Examples thereof include toluene (meth) acrylate, tetramethylol methanetetra (meth) acrylate, and trimethylolpropanetri (meth) acrylate. The amount used is appropriately selected according to the balance with the polymer to be crosslinked as described above, but is generally preferably 1 to 10 parts by weight per 100 parts by weight of the polymer.

As described above, the pressure-sensitive adhesive composition of the present invention preferably uses a specific polymer and is obtained by subjecting this polymer to a cross-linking treatment. If necessary, various conventionally known tackifiers can be blended in consideration of the balance with the properties. In addition, such an adhesive composition may optionally include various conventionally known additives such as inorganic or organic fillers, metal powders, powders such as pigments, particles, and foils. Can be.

The tamper-resistant protective sheet of the present invention is obtained by coating the above-mentioned pressure-sensitive adhesive composition on a support, and having a thickness of usually 5 to 5.
A pressure-sensitive adhesive layer having a thickness of 100 μm is formed,
The cross-linking treatment is performed integrally when the pressure-sensitive adhesive layer is formed. Here, as the above-mentioned support, those made of various materials such as plastic film, paper and nonwoven fabric can be used, and the thickness is usually preferably 10 to 200 μm. It is preferable to use a transparent or translucent plastic film for the support of the sheet to be attached to the display surface so that the display content of the article can be confirmed.

The protection sheet for falsification prevention according to the present invention thus configured may have a printed surface if necessary. When the protective sheet is produced, a material having a surface printed in advance on the support may be used, and further, the surface of the pressure-sensitive adhesive layer on the support may be printed.

The tamper-prevention method of the present invention is to provide a tamper-proof protective sheet having the above-mentioned structure on an article such as a certificate or a container, and to cover the article by sticking together the adhesive layers.
This prevents the display or the contents of the article from being changed. For example, the article may be sandwiched between the protective sheets, and the pressure-sensitive adhesive layers may be bonded to each other at the periphery of the sheet to cover the sheet. In this case, printing, printing, or writing may be performed on the pressure-sensitive adhesive layer. it can. In addition, one protective sheet may be folded and the adhesive surfaces may be bonded together, or two adhesive sheets of the protective sheet may be bonded together. When the latter two protection sheets are used, the same kind of protection sheet may be used, or different protection sheets such as a base material and printing may be used.

As another embodiment of the tamper-proof method of the present invention, an adhesive layer having a self-adhesive force of at least 2 kg / 20 mm width as in the tamper-proof protective sheet of the present invention on an article such as a certificate. The adhesive layer is printed, printed, or written on the adhesive layer, and the tamper-resistant protective sheet of the present invention is provided thereon. The above-mentioned pressure-sensitive adhesive layer and the above-mentioned pressure-sensitive adhesive layer may be bonded to each other to cover. In this case, if the pressure-sensitive adhesive layer is formed on an article such as the above-mentioned certificate, the article itself is considered to be a tampering prevention protective sheet of the present invention, if the article is considered as a kind of support. However, by selecting various materials including the above-mentioned articles as the support constituting the tamper-proof protective sheet provided thereon, any tamper-proof form can be taken.

[0022]

Next, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited by the following examples. In the following, “parts” means “parts by weight”.

Example 1 A four-necked separable flask equipped with a stirrer, a thermometer and a water separation tube was charged with polycarbonate [Daicel Chemical Industries, Ltd. "PLACCEL CD210P".
L ", hydroxyl value 115.9 KOH mg / g], 200 g, succinic anhydride 20.51 g, dibutyltin oxide (hereinafter referred to as DBTO) 102 mg as a catalyst, and
In the presence of a small amount of toluene as a solvent for discharging reaction water, the temperature was raised to 180 ° C. while stirring was started, and the temperature was maintained at this temperature. After a while, water separation was observed, and the reaction began to proceed. The reaction was continued for about 25 hours to obtain a polyester having a weight average molecular weight of 58,000.

After diluting the polyester with toluene to a solid concentration of 45% by weight, diphenylmethane diisocyanate [manufactured by Nippon Polyurethane Co., Ltd.] is used as a crosslinking agent per 100 parts (solid content) of the polyester. To MT "] (solid content) to prepare an adhesive composition. This composition was applied to a thickness of 38 by an applicator.
μm polyethylene terephthalate film (hereinafter P
ET film) and dried at 130 ° C. for 5 minutes to form a 50 μm-thick pressure-sensitive adhesive layer. Further, as an after-curer, aging for 2 days in an atmosphere of 50 ° C. To prepare a protection sheet for preventing tampering.

Example 2 A four-necked separable flask equipped with a stirrer, a thermometer, and a water separation tube was charged with polycarbonate [Daicel Chemical Industries, Ltd. "PLACCEL CD220P".
L ", hydroxyl value 56.1 KOH mg / g] 250 g, sebacic acid 25.28 g, DBTO 62 mg as a catalyst, and heated to 180 ° C. while stirring in the presence of a small amount of toluene as a reaction water discharge solvent. And maintained at this temperature. After a while, water separation was observed, and the reaction began to proceed. Continue the reaction for about 35 hours,
A polyester having a weight average molecular weight of 80,000 was obtained.

After diluting the polyester with toluene to a solid concentration of 40% by weight, diphenylmethane diisocyanate [manufactured by Nippon Polyurethane Co., Ltd.] is used as a crosslinking agent per 100 parts (solid content) of the polyester. MT)], 1 part (solid content), 0.5 part (solid content) of hexamethylene diisocyanate adduct of trimethylolpropane ["Coronate HL" manufactured by Nippon Polyurethane Co., Ltd.]
Was added to prepare a pressure-sensitive adhesive composition. This composition was applied on a PET film having a thickness of 38 μm by an applicator, and dried at 130 ° C. for 5 minutes to obtain a film having a thickness of 50 μm.
m, and then subjected to aging in an atmosphere of 50 ° C. for 2 days as an after-curer,
A tamper-resistant protection sheet was made.

Comparative Example 1 A reaction vessel equipped with a cooling pipe, a nitrogen introducing pipe, a stirrer and a thermometer was charged with 50 parts of ethyl acetate and toluene 5 as a solvent.
0 part, a monomer mixture consisting of 50 parts of 2-ethylhexyl acrylate, 45 parts of butyl acrylate, 4.9 parts of acrylic acid and 0.1 part of 2-hydroxyethyl acrylate, and 2,2 as a polymerization initiator. '-Azobisisobutyronitrile 0.1 part, and polymerized in a nitrogen stream,
An acrylic polymer having a weight average molecular weight of 700,000 was obtained.

100 parts of this acrylic polymer (solid content)
In this case, 2 parts (solid content) of a tolylene diisocyanate adduct of trimethylolpropane ("Coronate L" manufactured by Nippon Polyurethane Co., Ltd.) was added as a crosslinking agent to prepare a pressure-sensitive adhesive composition. This composition was applied to a 38 μm-thick PET film using an applicator, and
After drying at 30 ° C. for 5 minutes, a 50 μm-thick pressure-sensitive adhesive layer is formed. Further, after-aging is performed for 2 days in an atmosphere of 50 ° C. as a protective layer to prevent tampering. Was made.

The self-adhesive force and the anti-falsification property of each of the anti-falsification protection sheets of Examples 1 and 2 and Comparative Example 1 were measured by the following methods. The results of these measurements were as shown in Table 1 below.

<Measurement of self-adhesive force> Width 20 mm, length 150 mm
The tamper-resistant protective sheet is bent at the center and the adhesive layers are stuck together with a 2 kg roller. Initially (after 5 minutes at room temperature (23 ° C.)) and after standing at high temperature (2 hours at 50 ° C.) Days after), the peeling force (Kg / 20 mm width) was measured at a peeling speed of 300 mm / min.

<Tampering prevention> Width 20 mm, length 100 mm
At the center of the adhesive layer surface of the protection sheet for preventing tampering, a marker ((Zebra) Matsuki-Fine character (black)) is used for approximately 10
A "positive" character was written in the size of mm, and another tamper-proof protective sheet of the same size as above was attached to the adhesive layer surfaces. The anti-tampering properties at the initial stage (after 5 minutes at room temperature (23 ° C.)) and after standing at high temperature (after 2 days at 50 ° C.)
The two bonded protective sheets were loosely and manually peeled off by hand, and then bonded again. The state was visually observed, and evaluated according to the following three-grade criteria. ：: It is easy to see that the character was severely broken and peeled. Δ: The character was slightly distorted, and when carefully observed, it can be seen that the character was separated. ×: The character did not collapse, so it was not apparent that the film had peeled off.

[0032]

As is clear from the results in Table 1 above, the tamper-proof protective sheets of Examples 1 and 2 of the present invention are better than the tamper-proof protective sheets of Comparative Example 1. It can be seen that it has a self-adhesive force, is difficult to re-peel, and has excellent tamper-proofing properties.

[0034]

As described above, the present invention uses a specific tamper-proof protective sheet in which the self-adhesive force between the pressure-sensitive adhesive layers is 2 kg / 20 mm width or more, and this is used as a certificate or container. Is provided on the article, and the pressure-sensitive adhesive layers are attached to each other to cover the article, thereby causing a problem such as workability that has been inevitable in the method using the photocurable pressure-sensitive adhesive proposed above. In addition, it is possible to reliably and easily prevent changes in the contents such as the display of documents and containers and the like, and to provide a falsification prevention method with excellent practicality.

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Waka Hikosaka 1-1-2 Shimohozumi, Ibaraki-shi, Osaka Nitto Denko Corporation

Claims (4)

[Claims] 1. A protective sheet for preventing the display or contents of an article from being altered, comprising a support and an adhesive layer, wherein the self-adhesive force between the adhesive layers is 2 kg / 20 mm width or more. A tamper-resistant protection sheet characterized by the following. 2. The pressure-sensitive adhesive layer has the following formula: (Wherein, R is a linear or branched hydrocarbon group having 2 to 20 carbon atoms, and n is a natural number of 2 or more) having a polycarbonate structure having a repeating unit represented by the following formula: The protection sheet for falsification prevention according to claim 1, comprising-as a main component. 3. A polymer having a polycarbonate structure.
Is a diol component essentially comprising a polycarbonate diol, and a dicarboxylic acid component essentially comprising a dicarboxylic acid having a molecular skeleton of an aliphatic or alicyclic hydrocarbon group having 2 to 20 carbon atoms. 3. The falsification-preventing protective sheet according to claim 2, wherein the polyester is a polyester having a weight average molecular weight of 20,000 or more synthesized from the above. 4. A tamper-resistant protection sheet according to any one of claims 1 to 3 is provided on the article to prevent the display or the contents of the article from being changed, and the adhesive layers are stuck together. A tamper-proof method comprising coating an article.