JPH0335283A - Label for concealing - Google Patents

Abstract

PURPOSE:To allow concealing simply by sticking the label and to prevent the restoration to the original concealing state after the label is once peeled by segmenting the peeling force of a release layer to a light part and a heavy part by the irradiation quantity of ionization radiations. CONSTITUTION:The peeling force of the release layer 4 of the label 1 for concealing is segmented to the light part 6 and the heavy part 5 by the irradiation quantity of the ionization radiations. The peeling force is heavier as the irradiation quantity of the ionization radiations is larger. The release layer 4 is, therefore, formed by using a release agent of the light peeling force and is irradiated with the ionization radiation while the part to be lightly provided with the peeling force is held masked or the part to be heavily provided with the peeling force is irradiated twice. Since the release layer is provided partially in such a manner, the complete restoration to the original state is no longer possible if information is once tried to be obtd. The concealing property is thus assured.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a label that can make postcards and ordinary documents confidential with a simple operation. The present invention relates to a label for concealing information that cannot be restored to its original concealed state once peeled off.

(Prior Art) In recent years, with the development of the information society, various efforts have been made to preserve information for individuals and corporations. Conventionally, documents have been processed by recording information and then sealing it inside an envelope, but the work of sealing the document in the envelope and gluing it is complicated and unsuitable for processing a large amount of business.

For this reason, envelopes with a recording layer of pressure-sensitive copying paper on the inside are used for pay statements, IJA health insurance payment statements, bank account balance notices, and the like. However, sealed letters are more expensive than postcards as a means of communication.

On the other hand, postcards are a simple and inexpensive means of communication, but they lack the confidentiality of correspondence. Various types of postcards have been proposed to compensate for this drawback. For example, a postcard consists of a postcard and a cover paper that is removably attached to the surface of the postcard.In order to make the front cover removable, the surface of the postcard is coated with a transparent coating such as synthetic resin. It has been processed.

However, such a configuration requires a laminating device, which is not only time-consuming but also expensive when the number of postcards is small, and because of its structure, it cannot actually be used for personal information. There were drawbacks that were difficult to avoid.

(Problems to be Solved by the Invention) In view of the above-mentioned circumstances, the present invention enables concealment by simply pasting it on the surface of a postcard, and after concealment, the top sheet can be easily peeled off. To provide a concealing label which allows a transparent film surface having cosmetic properties to be exposed on the surface of a postcard by peeling it off, and which cannot be restored to its original concealed state once peeled off.

(Means for Solving the Problems) In order to solve the above problems, the inventors of the present invention, as a result of intensive research, have filed an application for a concealing label that combines a transparent film with a release layer on the surface and an opaque base material. did. As a result of further research on the peeling force of the release layer, the present inventors were able to create a concealing label that is extremely practical and can be mass-produced by arbitrarily adjusting the weight of the release layer using ionizing radiation. The present invention was completed based on the discovery that this can be done.

That is, the present invention provides a concealing label in which a release sheet, a transparent sheet having a release layer on its surface, and an opaque surface base material having an area larger than the area of the release layer are laminated via an adhesive. This is a concealing label characterized in that the peeling force of the layer is divided into a light part and a heavy part by irradiation with ionizing radiation.

(Function) The transparent sheet 2 used in the present invention can be made of cellophane, soft vinyl, polyethylene, hard vinyl chloride, polypropylene,
Films such as polyester and diacetate are used, but translucent papers such as high-strength glassine paper, impregnated paper, and tracing paper can also be used.

The release layer 4 provided on the surface of this transparent sheet is made of a silicone release agent containing polyorganosiloxane as a main component (
Solvent addition type, solvent condensation type, solventless type, emulsion type,
(UV curing type, EB curing type, etc.), fluororesin, and other mold release agents are used.

This type of release agent is used in gravure printing (gravure coater)
, a bar coater, a knife coater, a roll coater, a screen printing, or other conventional equipment.

The opaque surface base material 7 having a larger area than the release layer 4 may be the above-mentioned film treated to make it opaque, high-quality paper, art paper, coated paper, cast coated paper, foil paper, kraft paper, or laminate. Paper, impregnated paper, metallized paper, etc., metal foil such as aluminum foil, textiles, etc. can be used, and are bonded with the adhesive 8.

The adhesive 8 may be a rubber-based adhesive such as natural rubber, styrene-butadiene latex, styrene-isoprene block copolymer, recycled rubber, or synthetic rubber, an acrylic-based adhesive, a silicone-based adhesive, or a solvent-based or aqueous emulsion-based adhesive. , photomelt type, liquid curing type, etc., by coating or printing.

Among these, it is desirable to use a permanent adhesive type (so-called general-purpose type) that can be used permanently while remaining stuck to the adherend. It is desirable to use an adhesive having an adhesive strength (JIS Z 0273) to stainless steel of 800 g/25 m or more.

In addition, for the purpose of improving concealment, a colored pigment ink may be printed on the surface base material, an aluminum vapor-deposited film may be formed, or a carbon blank or a colored pigment may be mixed into the adhesive.

Of course, commercially available adhesive paper, adhesive sheet, etc., which are made of an opaque base material and treated with an adhesive on the back side, can also be used.

The present invention is characterized in that the peeling layer 4 is divided into a portion 5 with a heavy peeling force ('AM weight) and a portion 6 with a light peeling force ('AM weight) by irradiating the peeling layer 4 with ionizing radiation. The weight of the peeling force is closely related to the dose of ionizing radiation.

That is, as the irradiation amount increases, the peeling force becomes heavier.

Therefore, the release layer is formed using a release agent with a light release force, and then ionizing radiation is irradiated while masking the areas where the release force is low, or Mitaka irradiation is applied to the areas where the release force is heavy. There is. In particular, it is preferable to use a silicone-based mold release agent because the relationship between the irradiation amount and the peeling force is significant.

Irradiation with ionizing radiation is carried out by masking any location after forming a release layer on the transparent sheet or laminating the surface base material.

In addition to using ionizing radiation, there are other methods to control the peeling force, such as applying two different types of release agents and changing the coating thickness of the release layer. It is extremely difficult to control the peeling force, and once applied, the divided areas cannot be changed.

In the present invention, a portion with heavy peeling force is a portion that is never peeled off from the release layer during handling of mail or the like. The part where the peeling force is light is the part where the concealing label is started to be peeled off in order to obtain information, and the lighter the peeling force is, the more preferable it is. As a guide, the peeling force for light parts is 180 @ peeling (300
tm/min) less than 5 g/cm, preferably 3
g/co+. The peeling force of the heavy portion should be at least twice that of the light portion, but it is preferably set to about 9 to 25 g/cn.

Examples of the ionizing radiation in the present invention include electron beams, α rays, β rays, γ rays, x'a, and ultraviolet rays. Among these, α rays, β rays, γ rays, and XL are associated with the problem of danger to the human body, so electron beams and ultraviolet rays are preferably used because they are easy to handle and are widely used industrially. It will be done.

The amount of irradiation cannot be determined depending on the adhesive used, the surface base material, the transparent sheet, etc., but when using an electron beam, the amount of irradiation is in the range of about 0.8 to 20 Mrad, preferably 1
．． A range of 5 to 10 Mrad is preferable in terms of peeling force, cost, etc. If it is less than O-8 Mrad, the peeling force will not be strong enough, and irradiation exceeding 20 Mrad may deteriorate the transparent sheet of the base material. Therefore, it is undesirable.

Examples of electron beam irradiation methods include scanning method,
Curtain beam method, broad beam method, etc. are adopted, and the acceleration voltage when irradiating the electron beam is 100 to 300 KV.
The degree is appropriate.

Furthermore, when using ultraviolet light, it is necessary to incorporate a photoinitiator into the release layer, such as thioxanthone, benzoin, benzoin alkyl ether xanthone, dimethylxanthone, benzophenone, anthracene, etc.
2-Jethoxyacetophenone, benzyl dimethyl ketal, benzyl, diphenyl disulfide, anthraquinone, 1-chloroanthraquinone, 2-ethylanthraquinone, 2-tar-butylanthraquinone, N.

N'-tetraethyl-4,4'-diaminobenzophenone, 1. One or more photoinitiators such as 1-dichloroacetophenone are appropriately blended. It is desirable to adjust the amount of the photoinitiator used within the range of 0.2 to 101% by weight, preferably 0.5 to 5% by weight of the entire composition.

As a light source for ultraviolet irradiation, an ultraviolet lamp (for example, a low-pressure, medium-pressure, or high-pressure mercury lamp with an operating pressure of several mstHg to about 10 atmospheres), a xenon lamp, a tungsten lamp, etc. is used, and the radiation is about 5000 to 500 μm. Preferably, ultraviolet light having an intensity of .

The sheet laminated with a surface base material is further coated with a base material such as paper coated with polyethylene, clay-coated paper, super-calendered paper, glassine, parchment paper, various plastic films, etc., and silicone resin, fluorine thread resin, etc. A commonly used release sheet 9 provided with a release layer such as wax
After being integrated with the adhesive 3, it is cut into a predetermined size to become a concealing label. As the adhesive 3, the above-mentioned transparent adhesive is used.

Furthermore, in order to make it easier to peel off the surface base material, a more practical label can be obtained by providing intermittent perforation-like cuts 10 from the surface base material side to the release layer in areas where the peeling force is light.

Furthermore, the present invention has a structure in which an aluminum vapor-deposited film 11 is laminated on a release layer 4 with different peeling forces, and a surface base material having a larger area than the peeling N (aluminum vapor-deposited film) is provided via an adhesive. , a concealing label with extremely excellent concealing properties can be obtained.

Next, the method of using the concealing label according to the present invention will be explained in more detail with reference to the drawings.

Figures 1-A, 2-A, 3-A, and 4A are side sectional views of a concealing label according to an embodiment of the present invention;
Figure B, Figure 2-B, Figure 3-B, and Figure 4-B are front views.

The label 1 is simply peeled off from the release sheet 9 and pasted so that the transparent sheet 2 covers the confidential portion 13 of the postcard, regular document, etc.
As shown in FIGS. 3-C and 4-C, the situation becomes unknown to a third party. To obtain the content, refer to Figure 1-D, Figure 2-
As shown in Figure D, Figure 3-D, and Figure 4-D, ξ-thin-shaped intermittent cuts 10 are provided in the parts of the release layer where the peeling force is light.
When the surface base material 7 is further peeled off, a transparent sheet 2 with a transparent adhesive layer 4 therebetween appears on the confidential information document, and the information can be seen through the sheet. In the configuration shown in FIGS. 3 and 4 in which an aluminum vapor-deposited film is provided, the vapor-deposited film is transferred to the surface substrate and peeled off, so that a transparent sheet appears.

In addition, when the label of the present invention has the configuration shown in FIGS. 1 and 3,
If an attempt is made to peel off the hidden second half transparent surface base material 7, the surface of the postcard or the like 12 containing information will be peeled off because it is firmly adhered by the adhesive 8. In the case of the configurations shown in FIGS. 2 and 4, when attempting to peel off the opaque surface substrate 7, since it is firmly adhered by the adhesives 3 and 8, the surface of the postcard etc. 12 containing information or the surface substrate may be removed. The back side will peel off. In this way, the concealment label of the present invention has -d.
If you try to obtain information, it will no longer be possible to completely restore it to its original state, so concealment can be guaranteed.

Examples of the present invention will be described below, but it goes without saying that the present invention is not limited only to these examples.

Example 1 A commercially available silicone release agent was coated on the entire surface of polyethylene terephthalate (PET) using a bar coater at a coating amount of 0.4 g/n, and after drying and curing, it was masked with a width of 5 mm in the flow direction. 2 using an electron beam irradiation device (Electro Curtain CB-150: manufactured by ES1)
A transparent sheet was obtained by irradiating it with Mrad's electron beam to create areas with heavy peeling force.

On the release layer side of this sheet, a commercially available adhesive paper (manufactured by Kanzaki Seiki, Kantatsuku p<55>/P-22/PL) with an emulsion-type acrylic adhesive based on high-quality paper was used. In addition, an acrylic emulsion type adhesive was applied to a release sheet on the back side at a dry weight of 20 g/nl, and the dried products were bonded together to obtain a laminate, and then a laminate was performed to conceal the structure shown in Figure 1. I got a label for it.

Example 2 A concealing label was obtained in the same manner as in Example 1 except that the electron beam irradiation was performed at 5 Mrad.

Comparative Example 1 A concealing label was obtained in the same manner as in Example 1 except that electron beam irradiation was performed at 0.5 Mrad.

Comparative Example 2 Heavy release type addition type solvent silicone was applied to polyethylene terephthalate (PET) to give a weight of 10.4 g/cd, and after curing at 130°C for 30 seconds, the commercially available polyethylene terephthalate (PET) used in Example 1 was applied. A concealing label was prepared in the same manner as in Example 1, except that a transparent sheet was obtained by applying and drying a silicone release agent to a width of 5 μm and a coating amount of 0.4 g/-, and then forming a release layer with different release strengths. Obtained.

``Evaluation'' When the four types of concealment labels obtained in this way were attached to postcards with information printed on them, the contents could not be recognized, and the surface base material The peeling force required to peel off was measured for both light and heavy parts. The measurement was carried out using an Instron type tensile tester at 180 peel test (300 m/min), and the results shown in Table 1 were obtained.

Table 1 (Effects) As described above, the concealing label of the present invention has extremely excellent concealing properties. In addition, since the peeling layer is sufficiently heavy, it will not peel off even when used for mail, etc., and because it has a light peeling part in some areas, it is easy to peel off when obtaining information. .

Furthermore, since the release layer uses ionizing radiation, the release force can be flexibly adjusted and productivity is excellent. Further, since the concealing label of the present invention can carry out the concealing work with extremely simple work, it can also be applied to mechanization using a high-speed automatic labeler or the like.

[Brief explanation of drawings]

1-A, 2-A, 3-A, and 4A are side sectional views illustrating an embodiment of the concealing label of the present invention,
Figure 1-B, Figure 2-B, Figure 3-B, and Figure 4-B are front views of the labels, Figure 1-C, Figure 2-C, and Figure 3-C.
Figure 4-C is a side sectional view illustrating a state in which confidential information 13 is concealed using the concealing label of the present invention,
FIG. D, FIG. 2-D, FIG. 3-D, and FIG. 4-D are side sectional views illustrating a state in which the label is partially peeled off to obtain information. 1: Concealing label 2: Transparent sheet 3: Adhesive layer 4: Release layer 5: Heavy release area 6: Light release area 7: Surface base material 8: Adhesive layer 9: Release sheet 1O: Diagonal intermittent Target cut 11 Nialium vapor deposited film 12: Postcard etc. 13: Confidential document

Claims (5)

[Claims] (1) Release sheet, transparent sheet with a release layer on the surface,
In a concealing label in which an opaque surface substrate having an area larger than the area of the release layer is laminated via an adhesive, the peel force of the release layer is divided into a light part and a heavy part by irradiation with ionizing radiation. A concealing label characterized by: (2) Claim in which an aluminum vapor-deposited film is provided on the release layer (
1) Concealment label as described. (3) The concealing label according to any one of claims (1) to (2), wherein the release layer is composed of a silicone release agent. (4) Claims (1) to (3) in which the ionizing radiation is an electron beam.
Concealment label listed. (5) The electron beam irradiation dose of the heavy peeling part of the peeling layer is 1.5
The concealing label according to claim 4, wherein the concealing label ranges from Mrad to 10 Mrad.