Information concealment sheet

Abstract

To provide an information concealing sheet in which a main body piece and a concealing piece that are connected to each other are releasably adhered, and the sheet can leave a trace even if the main body piece and the concealing piece are peeled and unsealed immediately after they are adhered, and leaves a trace of peeling and unsealing only in a region necessary to detect unauthorized unsealing.SOLUTION: In a configuration in which a main body piece 10 and a concealing piece 20 are connected via a folding part 30, an unsealing detection part 12 is arranged along an upper side and a lower side of the main body piece 10, and a strong adhesive part 60 is provided in a region of the concealing piece 20 which faces the unsealing detection part 12 when the main body piece 10 and the concealing piece 20 are folded via the folding part 30, a plurality of V-shaped half slits 13 are formed in the unsealing detection part 12 with a protruding side facing an opposite side from the folding part 30, a half slit 14 is formed in a region along the side of an outer periphery of the unsealing detection part 12, and the half slit 14 is in contact with an end of an opening side of the half slits 13.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an information concealment sheet in which a main body piece and a concealment piece connected to each other are detachably adhered, and particularly relates to a technique for detecting that the main body piece and the concealment piece have been illegally peeled and unsealed from the adhered state.

Background Art

[0002] As a postcard, which is one of the information transmission media, a reciprocal postcard in which a main body piece having an information display column and a concealment piece for concealing the information displayed in the information display column are connected is used. Such a reciprocal postcard is folded through the connecting side of the main body piece and the concealment piece, and the information displayed in the information display column can be concealed by detachably adhering the main body piece and the concealment piece with an adhesive layer laminated on the concealment piece.

[0003] However, since the adhesive layer laminated on the concealment piece is for detachably adhering the main body piece and the concealment piece, there is a risk that the main body piece and the concealment piece may be illegally peeled and unsealed from the adhered state.

[0004] Here, Patent Document 1 discloses an information concealment form including a main body paper piece provided in a concealment information entry area for entering concealment information, and a concealment paper piece connected to the main body paper piece via a folding line and covering the concealment information entry area of the main body paper piece by folding back along the folding line. The outer part of the concealment information entry area of the main body paper piece is provided with a strip-shaped peeling part surrounded by a half-cut cut line along three sides excluding the folding line, and an adhesive layer part adhered along the longitudinal direction of each peeling part is provided at a part of the inner surface covering the concealment information entry area of the concealment paper piece that overlaps with the peeling part. According to this information concealment form, when the main body paper piece and the concealment paper piece are unsealed after being sealed, the peeling part will peel between the papers. Therefore, since a trace of unsealing remains due to the peeling between the papers of this peeling part, illegal unsealing can be detected.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Patent No. 5225181 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, in the invention disclosed in Patent Document 1, for the peeling portion to separate from the other paper when the main paper piece and the concealing paper piece are opened after being sealed, it is a prerequisite that the adhesive portion is strongly adhered to the peeling portion. Therefore, if the main paper piece and the concealing paper piece are opened immediately after being sealed, there is a risk that the peeling portion will not separate from the other paper and no trace of opening will remain.

[0007] Furthermore, in the invention disclosed in Patent Document 1, in order to ensure that delamination occurs between the paper at the peeling portion when the main paper piece and the concealing paper piece are opened after being sealed, a portion of the cut line is formed to face the adhesive layer. However, in this case, there is a risk that the delamination at the peeling portion may extend to the outer circumference of the main paper piece or to the information display area. In an information-concealing sheet such as a return postcard, in which a main piece having an information display area and a concealing piece for concealing the information displayed in the information display area are connected, after the main piece and the concealing piece are peeled apart from their attached state, mechanical processing such as machine reading of the information displayed in the information display area may be performed. In this case, it is necessary to maintain the outer shape of the sheet, but if the delamination at the peeling portion extends to the outer circumference of the main piece, the outer shape of the sheet cannot be maintained, and mechanical processing becomes impossible. In addition, if the delamination at the peeling portion extends to the information display area of ​​the main piece, there is a problem that the information displayed in the information display area will become unreadable.

[0008] The present invention has been made in view of the problems of the conventional technology described above, and aims to provide an information concealment sheet in which a main body piece and a concealing piece are detachably attached to each other, which can leave a trace even if the main body piece and the concealing piece are peeled open immediately after being attached, and can leave a trace of peeling open only in the area necessary to detect unauthorized opening. [Means for solving the problem]

[0009] To achieve the above objective, the present invention provides: An information-concealing sheet comprising a main body piece having an information display area and a concealing piece connected to the main body piece, wherein the sheet is folded so that the information display area faces inward via the connecting edge between the main body piece and the concealing piece, and the main body piece and the concealing piece are peelably attached by an adhesive layer laminated on the concealing piece, The main body piece has opening detection sections arranged along the upper and lower edges in the regions adjacent to the upper and lower edges that intersect with the connecting edge on the adhesive surface with the concealing piece, The concealing piece has a strongly adhesive portion in the area facing the opening detection portion when the main body piece and the concealing piece are folded via the connecting edge. The aforementioned opening detection unit is A first half-slit, which has an opening on the side opposite to the protruding side and is convex in shape with the protruding side facing away from the connecting edge, is formed so as to face the strong adhesive portion when the main body piece and the concealing piece are folded via the connecting edge, In the outer periphery of the opening detection section, at least in the region along the upper edge, lower edge, and the edge on the connecting edge side, a second half-slit is formed so as to surround the plurality of first half-slits. The second half-slit is in contact with the open end of the first half-slit.

[0010] In the present invention configured as described above, when the main body piece and the concealing piece are peeled open from the state in which they are attached by the adhesive layer, the opening detection parts provided in the regions adjacent to the upper and lower edges of the adhesive surface between the main body piece and the concealing piece are attached to the strong adhesive part provided on the concealing piece, and the first half-slit provided in the opening detection part triggers paper-to-paper delamination of the main body piece. At that time, the first half-slit has a convex shape with an opening on the side opposite to the protruding side, but the protruding side faces the opposite side from the connecting edge between the main body piece and the concealing piece, that is, the side where the peeling starts when the main body piece and the concealing piece are peeled apart, so paper-to-paper delamination is likely to occur and a trace can be left even if the main body piece and the concealing piece are peeled open immediately after being attached. Furthermore, while delamination spreads across the main body piece as it tears along the first half-slit, the opening detection unit has a second half-slit formed in a region along at least the top, bottom, and connecting edges of the outer circumference of the opening detection unit, surrounding the multiple first half-slits. This prevents the delamination of the main body piece from spreading beyond the opening detection unit, thereby preventing the delamination from reaching the outer circumference of the main body piece, making it impossible to maintain its shape, or from reaching the information display area of ​​the main body piece, making the displayed information unreadable. Additionally, because the second half-slit is in contact with the opening end of the first half-slit, the main body piece tears along the first and second half-slits as it delaminates. This reduces the likelihood of problems occurring during machine processing, such as machine reading of the information displayed in the information display area, due to unsightly tears or fraying of the main body piece caused by the tears.

[0011] Furthermore, if a third half-slit is formed on the outer circumference of the tamper detection section, surrounding the first and second half-slits, even if the delamination of the main body piece extends beyond the second half-slit, the third half-slit will prevent the delamination from spreading beyond the tamper detection section.

[0012] Furthermore, if multiple tamper detection units are provided along the upper and lower edges of the main piece, and multiple strong adhesive units are provided corresponding to the areas facing the multiple tamper detection units when the main piece and the concealing piece are folded along their connecting edges, the amount of strong adhesive unit exposed after peeling can be reduced without significantly reducing the adhesion area between the main piece and the concealing piece by the strong adhesive unit. Additionally, after the main piece and the concealing piece are peeled open from their adherent state, the peeled portion is less likely to curl, reducing the likelihood of problems occurring during mechanical processing such as machine reading of information displayed in the information display area. [Effects of the Invention]

[0013] According to the present invention, the first half-slit provided in the opening detection portion of the main body piece has a convex shape with an opening on the side opposite to the protruding side, and the protruding side is formed facing away from the connecting edge between the main body piece and the concealing piece. As a result, delamination between the paper layers is likely to occur, and even if the main body piece and the concealing piece are peeled open immediately after being attached, a trace of the peeling can be left. Furthermore, as a second half-slit is formed in the region along at least the upper edge, lower edge, and the connecting edge side of the outer circumference of the opening detection portion, surrounding the multiple first half-slits, the delamination between the paper layers of the main body piece is prevented from spreading outward beyond the opening detection portion by the second half-slit, thereby leaving a trace of the peeling open only in the area necessary to detect unauthorized opening.

[0014] Furthermore, in cases where a third half-slit is formed on the outer circumference of the tamper detection section, surrounding the first and second half-slits, even if the delamination of the main body piece extends beyond the second half-slit, the third half-slit prevents the delamination from spreading beyond the tamper detection section.

[0015] Furthermore, in a design where multiple tamper detection units are provided along the upper and lower edges of the main piece, and multiple strong adhesive units are provided corresponding to the areas facing the multiple tamper detection units when the main piece and the concealing piece are folded along their connecting edges, the amount of strong adhesive unit exposed after peeling can be reduced without significantly reducing the adhesion area between the main piece and the concealing piece by the strong adhesive unit. Additionally, after the main piece and the concealing piece are peeled open from their adherent state, the peeled portion is less likely to curl, reducing the likelihood of problems occurring during mechanical processing such as machine reading of information displayed in the information display area. [Brief explanation of the drawing]

[0016] [Figure 1] This figure shows a first embodiment of the information-concealing sheet of the present invention, where (a) is a diagram showing one side, (b) is a cross-sectional view of A-A' shown in (a), (c) is a cross-sectional view of B-B' shown in (a), and (d) is a diagram showing the other side. [Figure 2] Figure 1 shows the configuration of the concealed postcard after the release paper has been peeled off the concealing piece, where (a) shows the overall configuration and (b) shows the positional relationship between the opening detection part and the strong adhesive part when the main piece and the concealing piece are folded via the fold. [Figure 3] Figures 1 and 2 illustrate the method of use for attaching the main body piece and the concealing piece of the concealing postcard. [Figure 4] Figures 1 and 2 illustrate the process when the main body and concealing piece of the concealing postcard are peeled off after they have been attached to each other. [Figure 5] Figures 1 and 2 illustrate the operation of the first and second half-slits provided in the tamper detection section of the concealed postcard. [Figure 6] These figures illustrate the function of the third half-slit provided in the tamper-evident section of the concealed postcard shown in Figures 1 and 2. [Figure 7]It is a figure showing a second embodiment of the information hiding sheet of the present invention, (a) is a figure showing one surface, and (b) is a figure showing a configuration in which a release paper is peeled off from the hiding piece shown in (a). [Figure 8] It is a figure showing a third embodiment of the information hiding sheet of the present invention, (a) is a figure showing one surface, and (b) is a figure showing a configuration in which a release paper is peeled off from the hiding piece shown in (a). [Figure 9] It is a figure showing another form of the half slit formed inside the opening detection part shown in FIGS. 1, 7, and 8.

Embodiments for Carrying Out the Invention

[0017] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0018] (First Embodiment) FIG. 1 is a figure showing a first embodiment of the information hiding sheet of the present invention, (a) is a figure showing one surface, (b) is a cross-sectional view taken along the line A - A' shown in (a), (c) is a cross-sectional view taken along the line B - B' shown in (a), and (d) is a figure showing the other surface. FIG. 2 is a figure showing a configuration in which the release paper 40 is peeled off from the hiding piece 20 of the hiding postcard 1 shown in FIG. 1, (a) is a figure showing the overall configuration, and (b) is a figure showing the positional relationship between the opening detection part 12 and the strong adhesion part 60 when the main body piece 10 and the hiding piece 20 are folded via the folding part 30.

[0019] In this embodiment, as shown in FIGS. 1 and 2, it is a hiding postcard 1 in which a release paper 40 is adhered onto the hiding piece 20 on one surface of a base sheet 2 in which a main body piece 10 and a hiding piece 20 are connected with each one side as a connecting side.

[0020] A folding part 30 is formed on the connecting side of the main body piece 10 and the hiding piece 20 by a half slit, embossing, etc., and thereby, the base sheet 2 can be folded via the folding part 30.

[0021] One side of the main body piece 10 is provided with an information entry field 11 for writing information to be transmitted using this concealed postcard 1. Outside the information entry field 11, four tamper detection units 12 are arranged along the upper and lower edges of the main body piece 10 in areas adjacent to the upper and lower edges of the main body piece 10 that intersect with the fold 50. The shape of the tamper detection units 12 is not limited; as shown in Figure 1, they may be rectangular (strip-shaped) or square. Furthermore, the length between the outermost ends of the four tamper detection units 12 in the direction of alignment is preferably 80% or more of the length between the upper and lower edges of the main body piece 10. Alternatively, instead of the information entry field 11, a field with printed information to be transmitted using this concealed postcard 1 may be provided, and these together constitute an information display field.

[0022] Each of the tamper detection sections 12 has a V-shaped first half-slit 13, which is open on the side opposite to the protruding side, and is formed in a row along the upper and lower edges of the main body piece 10, with the protruding side facing away from the folded portion 30. In addition, each of the tamper detection sections 12 has a second half-slit 14 formed in a region along the outer edge of the tamper detection section 12 so as to surround the half-slit 13, and this half-slit 14 is in contact with the open end of the half-slit 13. Furthermore, each of the tamper detection sections 12 has a third half-slit 15 formed on the outer edge of the tamper detection section 12 so as to surround the half-slits 13 and 14. These half-slits 13 to 15 are formed from one side of the base sheet 2 so as not to penetrate the base sheet 2 from both sides, and their depths are the same, for example, 50% to 60% of the thickness of the base sheet 2.

[0023] The other side of the main body piece 10 is provided with an address information display area 16 where the recipient's address, name, or company name for the concealed postcard 1 is displayed.

[0024] On one side of the concealing piece 20, four strong adhesive portions 60 are provided by applying an adhesive to the area facing the opening detection portion 12 when the base sheet 2 is folded via the folding portion 30, thereby making it difficult to peel off the main body piece 10 and the concealing piece 20. The strong adhesive portions 60 are provided so as to face the multiple half slits 13 when the base sheet 2 is folded via the folding portion 30. Specifically, as shown in Figure 2(b), the strong adhesive portions 60 are provided so as to face the entire area surrounded by the half slits 14 when the base sheet 2 is folded via the folding portion 30. Of the four strong adhesive portions 60, the two strong adhesive portions 60 that are at the ends in the direction in which the four strong adhesive portions 60 are aligned are provided so as to have non-adhesive portions 61 on both ends in the direction in which the four strong adhesive portions 60 are aligned within the area surrounded by the half slits 14 that do not face the strong adhesive portions 60. Furthermore, "difficult to peel off" means that when the main body piece 10 and the concealing piece 20 are peeled off by human hands after they have been attached, the main body piece 10 itself tears or peels off in the thickness direction. In addition, on one side of the concealing piece 20, a pseudo-adhesive layer 50 is laminated, which enables the main body piece 10 and the concealing piece 20 to be peeled off after they have been attached, by applying, for example, a weak adhesive to the area sandwiched between a strong adhesive portion 60 provided along the upper edge of the concealing piece 20 and a strong adhesive portion 60 provided along the lower edge of the concealing piece 20. This pseudo-adhesive layer 50 may also be laminated by applying the adhesive in a dot pattern, grid pattern, or diagonal pattern. In that case, the amount of adhesive can be reduced. Then, a release paper 40 is peelably attached to cover these pseudo-adhesive layers 50 and strong adhesive portions 60. Furthermore, by printing a background pattern or the like on the area where the pseudo-adhesive layer 50 of the concealing piece 20 is laminated, it is possible to prevent the information written in the information entry field 11 of the main piece 10 from being seen through when the main piece 10 and the concealing piece 20 are attached. In that case, the background pattern or the like would be printed on the concealing piece 20 before the pseudo-adhesive layer 50 is laminated. Also, in the pseudo-adhesive layer 50, the adhesive strength is not to be constant in all areas, but rather the adhesive strength may be made different in multiple areas, for example, by making the adhesive strength stronger in the area along the periphery and weaker in the area surrounded by it.By increasing the adhesive strength in the area along the periphery and decreasing the adhesive strength in the area surrounded by it, it is possible to prevent the concealing piece 20 from unintentionally peeling off the main body piece 10 after the concealing piece 20 and the main body piece 10 have been peelably attached.

[0025] The release paper 40 has one edge that overlaps with the edge of the concealing piece 20 that is opposite to the folded portion 30, and is provided with an address information display area 41 where the address, name, or company name of the recipient of the concealing postcard 1 is displayed.

[0026] The following describes how to use the concealed postcard 1, which is configured as described above.

[0027] First, we will explain how to use the concealing postcard 1 shown in Figures 1 and 2, up to the point of attaching the main body piece 10 and the concealing piece 20.

[0028] Figure 3 is a diagram illustrating the method of use for attaching the main body piece 10 and the concealing piece 20 of the concealing postcard 1 shown in Figures 1 and 2.

[0029] As shown in Figures 1 and 2, the concealed postcard 1 is delivered to the recipient according to the address information 41a displayed in the address information display area 41 of the release paper 40, as shown in Figure 3(a). After that, information that the recipient of the concealed postcard 1 wants to notify the return recipient, such as application information 11a, is entered in the information entry field 11.

[0030] Next, in order to submit an application using the application information 11a entered in the information entry field 11, the release paper 40 is peeled off the concealing piece 20, as shown in Figure 3(b). This exposes the pseudo-adhesive layer 50 and the strong adhesive portion 60 that were provided in the area where the release paper 40 of the concealing piece 20 was attached.

[0031] Subsequently, as shown in Figure 3(c), the postcard is folded via the folding portion 30 so that the side with the information entry field 11 faces inward, and the main body piece 10 and the concealing piece 20 are attached by the pseudo-adhesive layer 50 and the strong adhesive portion 60. The postcard is then sent to the recipient of the concealed postcard 1 according to the recipient information 16a displayed in the recipient information display area 16 of the main body piece 10. At this time, because the concealing piece 20 is attached to the side of the main body piece 10 with the information entry field 11, it is prevented that the application information 11a written in the information entry field 11 may be viewed during transit of the concealed postcard 1.

[0032] Next, we will explain the action that occurs when the main body piece 10 and the concealing piece 20 of the concealing postcard 1 shown in Figures 1 and 2 are peeled off after they have been attached.

[0033] Figure 4 is a diagram illustrating the action that occurs when the main body piece 10 and the concealing piece 20 of the concealing postcard 1 shown in Figures 1 and 2 are peeled off after being attached.

[0034] As described above, when the concealed postcard 1 is delivered to the recipient with the main body piece 10 and the concealed piece 20 attached, as shown in Figure 4(a), the main body piece 10 and the concealed piece 20 are peeled off at the end opposite to the fold 30, in order to verify the application information 11a written in the information entry field 11 at the recipient's end of the concealed postcard 1.

[0035] As the main body piece 10 and the concealing piece 20 are separated, in the region where the pseudo-adhesive layer 50 of the concealing piece 20 is laminated, the main body piece 10 and the concealing piece 20 are peelably attached by the pseudo-adhesive layer 50, causing the peeling piece 20 to detach from the main body piece 10. On the other hand, in the region where the strong adhesive portion 60 of the concealing piece 20 is provided, the main body piece 10 and the concealing piece 20 are difficult to peel off due to the strong adhesive portion 60, causing inter-paper delamination at the main body piece 10. Furthermore, since the region of the main body piece 10 facing the strong adhesive portion 60 is provided, the main body piece 10 is de-papered at the opening detection portion 12, and as shown in Figure 4(b), a part of the main body piece 10 becomes an inter-paper de-separated portion 17b and remains attached to the concealing piece 20 by the strong adhesive portion 60, while the inter-paper de-separated portion 17a remains on the main body piece 10 side.

[0036] In this way, when the main body piece 10 and the concealing piece 20 of the concealing postcard 1 are attached to each other and then separated, the paper-to-paper separation of the main body piece 10 creates paper-to-paper separation portions 17a and 17b, leaving traces of peeling and opening, which allows for the detection of unauthorized opening.

[0037] Here, we will explain the function of the half-slits 13 and 14 provided in the opening detection unit 12.

[0038] Figure 5 is a diagram illustrating the operation of the half-slits 13 and 14 provided in the tamper detection section 12 of the concealed postcard 1 shown in Figures 1 and 2.

[0039] As described above, the half-slit 13 provided in the opening detection section 12 has a V-shape with the side opposite the protruding side open, and the protruding side faces away from the fold portion 30 which is the connecting edge between the main body piece 10 and the concealing piece 20. On the other hand, the main body piece 10 and the concealing piece 20, which are peelably attached to each other, are folded and peelably attached via the fold portion 30, so they peel off from each other with the side opposite the fold portion 30 as the peeling start end. As a result, the area in the opening detection section 12 where the half-slit 13 is formed is attached to the concealing piece 20 by the strong adhesive portion 60, so as shown in Figure 5(a), the V-shaped area enclosed by the half-slit 13 begins to peel from the apex of the V-shape where its area is narrower, and a part of it becomes a paper-peel portion 17b which remains attached to the concealing piece 20, while the paper-peel portion 17a which has peeled off from the paper-peel portion 17b remains on the main body piece 10 side. Furthermore, in order to produce the effects described above, the strong adhesive portion 60 must be positioned so as to face the V-shaped apex of the half-slit 13 when the base sheet 2 is folded via the folding portion 30.

[0040] Subsequently, as shown in Figure 5(a), when the torn portion 18 of the main body piece 10 due to delamination reaches the open end of the half slit 13, the open end of the half slit 13 is in contact with the half slit 14. As a result, the torn portion 18 of the main body piece 10 due to delamination moves along the half slit 13 and the half slit 14, as shown in Figure 5(b), causing the main body piece 10 to delaminate.

[0041] Thus, in the opening detection section 12, the half-slit 13, which has a V-shape with an opening on the opposite side from the protruding side, is formed with the protruding side facing the peeling start end side that separates the main body piece 10 and the concealing piece 20. This makes it easy for delamination between the paper layers to occur, and even if the main body piece 10 and the concealing piece 20 are peeled open immediately after being attached, a trace can be left. Furthermore, even if the main body piece 10 and the concealing piece 20 are attached with weak force, a trace can be left. In addition, because delamination between the paper layers is easy to occur, even if the adhesive strength of the strong adhesive section 60 is weakened by applying a thin layer of adhesive to the strong adhesive section 60, delamination between the paper layers can still occur. This prevents the print from peeling off if information is printed on the surface of the release paper 40 that is attached to the concealing piece 20.

[0042] Furthermore, as described above, when the main body piece 10 and the concealing piece 20 of the concealing postcard 1 are attached and then separated, the torn portion 18 of the main body piece 10 due to the paper-to-paper separation follows the half-slits 13 and 14, causing the main body piece 10 to separate from the paper. This prevents the separation from extending to the outer periphery of the main body piece 10, making it impossible to maintain the shape of the main body piece 10, and also prevents the separation from extending to the information entry field 11 of the main body piece 10, making the information entered in the information entry field 11 unreadable.

[0043] Furthermore, as described above, the torn portion 18 of the main body piece 10 due to delamination moves along the half-slits 13 and 14, causing the main body piece 10 to delaminate. This reduces the likelihood of problems occurring when the machine reads the information displayed in the information entry field 11, as the torn portion of the main body piece 10 may become unsightly or the main body piece 10 may become fuzzy due to the tearing.

[0044] Next, we will explain the function of the half-slit 15 provided in the opening detection unit 12.

[0045] Figure 6 is a diagram illustrating the operation of the half-slit 15 provided in the tamper detection section 12 of the concealed postcard 1 shown in Figures 1 and 2.

[0046] As described above, when the main body piece 10 and the concealment piece 20 of the concealment postcard 1 are attached and then separated, the torn portion 18 of the main body piece 10 due to paper-to-paper delamination will move along the half-slits 13 and 14. However, since a half-slit 15 is formed on the outer circumference of the opening detection unit 12, surrounding the half-slits 13 and 14, even if the torn portion 19 of the main body piece 10 due to paper-to-paper delamination extends outside the half-slit 14 as shown in Figure 6(a), the half-slit 15 prevents the paper-to-paper delamination of the main body piece 10 from spreading beyond the opening detection unit 12, as shown in Figure 6(b).

[0047] As described above, in this embodiment, even if the main body piece 10 and the concealing piece 20 are peeled open immediately after being attached, a trace of the peeling open can be left, and the trace of the peeling open can be left only in the area necessary to detect unauthorized opening. Multiple opening detection units 12 are provided along the upper and lower edges of the main body piece 10 to produce such an effect, and multiple strong adhesive units 60 are provided corresponding to each of the areas facing the multiple opening detection units 12 when the main body piece 10 and the concealing piece 20 are folded via the folding unit 30. As a result, the amount of strong adhesive units 60 that are partially exposed after peeling between the paper can be reduced without significantly reducing the area of ​​adhesion between the main body piece 10 and the concealing piece 20 by the strong adhesive units 60. This reduces the possibility of problems occurring when the surface becomes sticky due to the strong adhesive portion 60 after the main body piece 10 and the concealing piece 20 are separated, or when mechanical processing such as machine reading of the information displayed in the information entry field 11 is performed. Furthermore, when the main body piece 10 and the concealing piece 20 are peeled apart and opened from their attached state, the separated portion of the paper is less likely to curl, which also reduces the likelihood of problems occurring when mechanical processing such as machine reading of the information displayed in the information entry field 11 is performed.

[0048] (Second Embodiment) Figure 7 shows a second embodiment of the information-concealing sheet of the present invention, where (a) is a diagram showing one side, and (b) is a diagram showing the configuration after peeling the release paper 40 from the concealing piece 120 shown in (a).

[0049] As shown in Figure 7, this embodiment differs from those shown in Figures 1 and 2 in that the opening detection portion 112 provided on the main body piece 110 is a single strip-shaped portion extending along the upper and lower edges of the main body piece 110 in the areas adjacent to the upper and lower edges of the main body piece 110, and the strong adhesive portion 160 provided on the concealing piece 20 is provided in a strip-shaped portion in the area facing the opening detection portion 112 when the base sheet 2 is folded via the folding portion 30, corresponding to the opening detection portion 112. The opening detection section 112 has multiple V-shaped half-slits 113, similar to those shown in Figures 1 and 2, arranged in a row along the upper and lower edges of the main body piece 110, with the protruding side facing away from the folded portion 30. In addition, in the region along the outer edge of the opening detection section 112, multiple half-slits 114 are formed so as to surround the half-slits 113, in contact with the open end of the half-slits 13. Furthermore, half-slits 115 are formed on the outer edge of the opening detection section 112 so as to surround the half-slits 113 and 114. Preferably, the length of the opening detection section 112 in the longitudinal direction is 80% or more of the length of the upper and lower edges of the main body piece 110.

[0050] Even in the concealed postcard 101 configured as described above, when the main body piece 110 and the concealed piece 120 are peeled apart after being attached, the half-slit 113 makes it easier for the main body piece 10 to peel apart at the tamper detection unit 112, and the half-slits 114 and 115 prevent the peeling from spreading outward beyond the tamper detection unit 112.

[0051] Furthermore, in this embodiment, the strong adhesive portion 160 provided on the concealing piece 20 is provided in a strip shape within the area facing the opening detection portion 112 when the base sheet 2 is folded via the folding portion 30. This prevents the areas along the upper and lower edges of the main piece 110 and the concealing piece 120 from partially lifting or other mail items from getting caught when the main piece 110 and the concealing piece 120 are attached together.

[0052] (Third embodiment) Figure 8 shows a third embodiment of the information-concealing sheet of the present invention, where (a) is a diagram showing one side, and (b) is a diagram showing the configuration after peeling the release paper 40 from the concealing piece 220 shown in (a).

[0053] As shown in Figure 8, this embodiment is a concealed postcard 201 that differs from those shown in Figures 1 and 2 in that multiple dot-glued areas 70 are provided along the side of the concealed piece 220 opposite to the folded portion 30, for example, by applying the adhesive constituting the strong adhesive portion 60 in a dot pattern. The release paper 40 is peelably attached to the concealed piece 220 so as to cover the pseudo-adhesive layer 50, the strong adhesive portion 60, and the dot-glued areas 70.

[0054] In the concealed postcard 201 configured as described above, when the main body piece 10 and the concealed piece 220 are attached and then separated, the half-slit 13 makes it easier for the main body piece 10 to be separated from the paper by the opening detection unit 12, and the half-slits 14 and 15 prevent the separation from spreading outward beyond the opening detection unit 12. Furthermore, in the concealed postcard 201 of this embodiment, multiple adhesive dots 70 are provided along the side of the concealed piece 220 opposite to the folded portion 30, which is the starting end for separation when the main body piece 10 and the concealed piece 220 are attached and then separated, thereby preventing the concealed postcard 201 from being unintentionally peeled open during transit.

[0055] In the above-described embodiment, the depths of the half-slits 13-15 and 113-115 are the same. However, in order to reliably prevent the delamination between the paper sheets, triggered by the half-slits 13 and 113, from spreading outward beyond the opening detection units 12 and 112, it is preferable that the depths of the half-slits 14, 15, 114, and 115 be greater than or equal to that of the half-slits 13 and 113.

[0056] Furthermore, in the above-described embodiment, half-slits 14, 114 are formed in the region along the outer edges of the opening detection sections 12, 112. However, in order for the torn portion of the main body piece 10, 110 caused by delamination between the paper sections triggered by the half-slits 13, 113 to follow the half-slits 14, 114, the half-slits 14, 114 only need to be formed in the region along at least the upper edge, lower edge, and the edge on the folding portion 30 side of the outer perimeter of the opening detection sections 12, 112, so as to surround a plurality of half-slits 13, 113. In that case, in order for the half-slits 14, 114 to surround all of the plurality of half-slits 13, 113, the end of the half-slit 14, 114 opposite to the folding portion 30 should be positioned so as to sandwich at least the half-slit 13, 113 that is furthest from the folding portion 30, and the half-slit 14, 114 should extend from there toward the folding portion 30.

[0057] Furthermore, in the above-described embodiment, the strong adhesive portions 60 and 160 are provided so as to face the entire area enclosed by the half slits 14 and 114 when the base sheet 2 is folded via the folding portion 30, and the length of the strong adhesive portions 60 and 160 in the short direction is the same as the length of the area enclosed by the half slits 14 and 114. However, the length of the strong adhesive portions 60 and 160 in the short direction only needs to be less than or equal to the length of the area enclosed by the half slits 14 and 114 in the short direction.

[0058] Furthermore, in the above-described embodiment, the half-slits 13, 113 formed in the tamper detection sections 12, 112 were described as V-shaped with the opposite side to the protruding side open. However, the half-slits 13, 113 formed in the tamper detection sections 12, 112 are not limited to V-shaped, as long as they have a convex shape, such as a U-shaped shape with the opposite side to the protruding side open. However, if the half-slits have an apex angle like a V-shape, when the main body pieces 10, 110 and the concealing pieces 20, 120, 220 are separated, paper-to-paper delamination is more likely to occur on the main body piece 10, triggered by the half-slits 13, 113.

[0059] Figure 9 shows another form of the half-slit formed inside the opening detection section 12,112 shown in Figures 1, 7, and 8.

[0060] The half-slits formed inside the opening detection sections 12 and 112 may be half-slits 313, 413, and 513 using an arc, as shown in Figures 9(a) to (c), or half-slits 613 and 713 that are roughly U-shaped with three sides, as shown in Figures 9(d) and (e). Furthermore, they may be half-slits 813 and 913 using two sides that intersect on the opposite side of the fold 30, as shown in Figures 9(f) and (g). In addition, the half-slits 613, 713, 813, and 913 shown in Figures 9(d) to (g) may have a rounded shape at the point where the two sides intersect.

[0061] Furthermore, in the configurations shown in Figures 1 and 8, multiple half-slits 13 are provided for each of the four opening detection units 12, but it is also acceptable to have a configuration in which only one half-slit 13 is provided for each of the four opening detection units 12. [Explanation of Symbols]

[0062] 1,101,201 Concealing Postcards 2 base sheet 10,110 Body piece 11. Information entry field 11a Application Information 12,112 Opening detection unit 13-15, 113-115 Half Slit 16,41 Destination information display area 16a, 41a Destination Information 17a, 17b Paper separation section 18. Fracture 19 Fracture 20,120 Concealing Pieces 30 Folding section 40 Release paper 50 Pseudo-adhesive layer 60,160 Strong adhesive part 61 Non-stick area 70 dot glue part

Claims

1. An information-concealing sheet comprising a main body piece having an information display area and a concealing piece connected to the main body piece, wherein the sheet is folded so that the information display area faces inward via the connecting edge between the main body piece and the concealing piece, and the main body piece and the concealing piece are peelably attached by an adhesive layer laminated on the concealing piece, The main body piece has opening detection sections arranged along the upper and lower edges in the regions adjacent to the upper and lower edges that intersect with the connecting edge on the adhesive surface with the concealing piece, The concealing piece has a strongly adhesive portion in the area facing the opening detection portion when the main body piece and the concealing piece are folded via the connecting edge. The aforementioned opening detection unit is A first half-slit, which has an opening on the side opposite to the protruding side and is convex in shape with the protruding side facing away from the connecting edge, is formed so as to face the strong adhesive portion when the main body piece and the concealing piece are folded via the connecting edge, In the outer periphery of the opening detection section, a second half-slit is formed so as to surround a plurality of first half-slits in a region along at least the upper edge, lower edge, and the edge on the connecting edge side. The second half-slit is in contact with the open end of the first half-slit. The information-concealing sheet further comprises an information-concealing sheet in which a third half-slit is formed on the outer circumference of the opening detection unit, surrounding the first and second half-slits.

2. In the information concealment sheet according to claim 1, Multiple opening detection units are provided along the upper and lower edges, respectively. The strong adhesive portion is provided in multiple locations corresponding to each of the regions facing the multiple opening detection portions when the main body piece and the concealing piece are folded along the connecting edge, in an information concealing sheet.

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