Pseudo adhesive sheet

Abstract

To provide a pseudo adhesive sheet that is designed to prevent unintended peeling and can be effortlessly peeled by hand.SOLUTION: A pseudo adhesive sheet 1 includes a first substrate 10, a second substrate 20, and a pseudo adhesive layer 30 disposed between the first substrate 10 and the second substrate 20. The pseudo adhesive layer 30 includes cellulose acetate.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a pseudo-adhesive sheet. [Background technology]

[0002] A pseudo-adhesive label is known as a pseudo-adhesive technology. A pseudo-adhesive label is a label that can be easily peeled from the substrate starting from the pseudo-adhesive interface after being attached to an adherend. Pseudo-adhesive labels have been put to practical use as, for example, delivery slips or information concealment labels. The pseudo-adhesion technology is also used in sheets in which substrates are bonded together, etc. For example, as such a pseudo-adhesion sheet, Patent Document 1 describes a confidential thermosensitive recording medium that includes a first sheet having a first substrate and a first thermosensitive recording layer formed on one side of the first substrate, and a second sheet having a pseudo-adhesion layer and a second substrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-279788 Summary of the Invention [Problem to be solved by the invention]

[0004] Such pseudo-adhesive sheets are cut to a size according to the intended use, for example, when used. However, if the sheet becomes non-flat due to bending along a roll during post-processing such as cutting, the sheet may become wavy or warped. Furthermore, such warping may occur during transportation and storage depending on the transportation and storage conditions of the pseudo-adhesive sheet. Furthermore, due to the nature of pseudo-adhesion, such warping may cause the substrate to unintentionally peel off. On the other hand, when the pseudo adhesive sheet is used as a confidential postcard or the like, it is opened by hand, and therefore it is required that it can be opened (peel off) easily intentionally.

[0005] An object of the present invention is to provide a pseudo-adhesive sheet that can be easily peeled off by hand while preventing unintentional peeling. [Means for solving the problem]

[0006] According to one aspect of the present invention, there is provided a pseudo-adhesive sheet having a first substrate, a second substrate, and a pseudo-adhesive layer disposed between the first substrate and the second substrate, wherein the pseudo-adhesive layer comprises cellulose acetate.

[0007] In a pseudo-adhesive sheet according to one embodiment of the present invention, the first substrate has a first substrate surface and a second substrate surface opposite the first substrate surface, and it is preferable that the first substrate surface is in direct contact with the pseudo-adhesive layer.

[0008] In the pseudo adhesive sheet according to one embodiment of the present invention, it is preferable that the second substrate surface is printed.

[0009] In the pseudo adhesive sheet according to one embodiment of the present invention, when the first substrate is peeled from the pseudo adhesive layer, the peeling occurs at the interface between the first substrate and the pseudo adhesive layer.

[0010] In one embodiment of the pseudo-adhesive sheet of the present invention, it is preferable that the peel strength when the first substrate is peeled from the pseudo-adhesive layer at a peel rate of 0.3 m / min in a 180-degree peel test in accordance with JIS K6854-2:1999 is 5000 mN / 25 mm or more, and when the first substrate is peeled from the pseudo-adhesive layer at a peel rate of 0.3 m / min in a T-peel test in accordance with JIS K6854-3:1999, the peel strength is 1500 mN / 25 mm or less.

[0011] In a pseudo-adhesive sheet according to one embodiment of the present invention, the second substrate preferably has a third substrate surface on the pseudo-adhesive layer side and a fourth substrate surface opposite the third substrate surface, and is printed on the third substrate surface.

[0012] In the pseudo-adhesive sheet according to one embodiment of the present invention, the coating amount of the pseudo-adhesive layer is 3 g / m 2 More than 7g / m 2 It is preferable that: [Effects of the Invention]

[0013] According to one aspect of the present invention, it is possible to provide a pseudo-adhesive sheet that can be easily peeled off by hand while preventing unintentional peeling. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a schematic cross-sectional view of a pseudo adhesive sheet according to one embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional schematic view illustrating the state in which the pseudo-adhesive sheet is peeled off in a 180-degree peel test in the examples. [Figure 3] FIG. 2 is a cross-sectional schematic diagram illustrating the state in which a pseudo-adhesive sheet is peeled off in a T-peel test in the examples. DETAILED DESCRIPTION OF THE INVENTION

[0015] The present invention will be described below by taking an embodiment according to one aspect of the present invention as an example, but the present invention is not limited to this embodiment.

[0016] [Embodiment according to one aspect of the present invention] <Pseudo adhesive sheet> The pseudo-adhesive sheet according to this embodiment includes a first substrate, a second substrate, and a pseudo-adhesive layer disposed between the first substrate and the second substrate. The pseudo-adhesive layer pseudo-adheres to at least one of the first substrate and the second substrate. In this specification, "pseudo-adhesion" refers to an adhesion in which one layer and another layer that are bonded together under specific conditions (e.g., a combination of materials and a temperature range) can be easily peeled off at the interface, and the layer does not exhibit re-adhesion or re-stickiness after peeling.

[0017] 1 shows a schematic cross-sectional view of a pseudo adhesive sheet 1 according to this embodiment. In the pseudo adhesive sheet 1 according to this embodiment, a first substrate 10, a pseudo adhesive layer 30, and a second substrate 20 are laminated in this order. The first substrate 10 has a first substrate surface 10A and a second substrate surface 10B opposite the first substrate surface 10A, and the first substrate surface 10A is in direct contact with the pseudo-adhesive layer 30. The second substrate 20 has a third substrate surface 20A and a fourth substrate surface 20B opposite the third substrate surface 20A. The third substrate surface 20A is the surface on the pseudo-adhesive layer 30 side, and the third substrate surface 20A is in direct contact with the pseudo-adhesive layer 30.

[0018] In the pseudo adhesive sheet 1 according to this embodiment, the pseudo adhesive layer 30 is pseudo-adhered to the first substrate 10. That is, the first substrate 10 and the pseudo adhesive layer 30 are pseudo-adhered to each other at the interface A. In the pseudo adhesive sheet 1 according to this embodiment, when the first substrate 10 as one layer is peeled from the pseudo adhesive layer 30 as the other layer, peeling can be performed at the interface A between the first substrate 10 and the pseudo adhesive layer 30. After peeling, the surface of the first substrate 10 on the interface A side and the surface of the pseudo adhesive layer 30 on the interface A side do not exhibit re-adhesion or re-stickiness.

[0019] There is no particular limitation on the shape of the pseudo adhesive sheet 1. Examples of the shape of the pseudo adhesive sheet 1 in plan view include polygons (for example, rectangles and triangles), circles, ellipses, and irregular shapes.

[0020] (First substrate and second substrate) There are no particular limitations on the first substrate 10 and the second substrate 20 of the pseudo adhesive sheet according to this embodiment. The first substrate 10 and the second substrate are appropriately selected from conventionally known substrates depending on the intended use of the pseudo adhesive sheet 1. In the pseudo adhesive sheet 1, the first substrate 10 can be, for example, an information display substrate that displays information about the adherend. For example, if the adherend is a delivery item, the information about the adherend can include the name or title of the sender, recipient, and delivery company, address, telephone number, and contents of the delivery item.

[0021] The second substrate surface 10B is preferably printable, and the third substrate surface 20A is also preferably printable. If printing can be performed on the second substrate surface 10B and / or the third substrate surface 20A, the pseudo adhesive sheet 1 can be used as a personal postcard or the like.

[0022] (pseudo adhesive layer) The pseudo-adhesive layer 30 of the pseudo-adhesive sheet 1 according to this embodiment contains cellulose acetate. By containing cellulose acetate, the pseudo-adhesive layer 30 is prevented from unintentional peeling during post-processing and transportation, and can be easily peeled off by hand.

[0023] Cellulose acetate The cellulose acetate preferably has an acetylation degree of 55%. Furthermore, the cellulose acetate preferably has a 6% viscosity (viscosity when diluted to 6%) of 50 mPa·s or more and 200 mPa·s or less. The melting point of the cellulose acetate is preferably 230°C or higher and 300°C or lower. The viscosity of cellulose acetate can be measured, for example, according to the method specified in JIS K7117-1:1999. The melting point of cellulose acetate can be measured, for example, according to the method specified in JIS K7121-1987.

[0024] The pseudo-adhesive layer 30 may be a layer made of only cellulose acetate. If the pseudo-adhesive layer 30 is a layer made of only cellulose acetate, the pseudo-adhesive sheet 1 will also be a sheet with excellent biodegradability. Alternatively, the pseudo-adhesive layer 30 may contain other components such as additives in addition to cellulose acetate, as long as the effects of this embodiment are not impaired.

[0025] Other ingredients For example, the pseudo-adhesive layer 30 may contain a plasticizer, such as a phthalate ester compound such as diethyl phthalate, triethyl phosphate, dibutyl tartrate, or triethyl citrate.

[0026] There are no particular limitations on the thickness of the pseudo-adhesive layer 30. The thickness of the pseudo-adhesive layer 30 is preferably 1 μm or more and 50 μm or less, more preferably 3 μm or more and 40 μm or less, even more preferably 5 μm or more and 40 μm or less, even more preferably 7 μm or more and 30 μm or less, and even more preferably 10 μm or more and 25 μm or less.

[0027] When the pseudo-adhesive layer 30 is a layer made of only cellulose acetate, the coating amount of cellulose acetate in the pseudo-adhesive layer 30 is 3 g / m 2 More than 7g / m 2 The coating amount of cellulose acetate in the pseudo-adhesive layer 30 is preferably 3 g / m or less. 2 If the applied amount of cellulose acetate in the pseudo-adhesive layer 30 is 7 g / m or more, the adhesiveness is good. 2 If it is less than this, the releasability will be good.

[0028] The pseudo-adhesive sheet 1 of this embodiment preferably has a peel strength of 5000 mN / 25 mm or more when the first substrate 10 is peeled from the pseudo-adhesive layer 30 at a peel rate of 0.3 m / min in a 180-degree peel test in accordance with JIS K6854-2:1999, and a peel strength of 1500 mN / 25 mm or less when the first substrate 10 is peeled from the pseudo-adhesive layer 30 at a peel rate of 0.3 m / min in a T-peel test in accordance with JIS K6854-3:1999. The 180-degree peel test is designed to prevent the sheet from twisting, etc., so if the peel strength in the 180-degree peel test is 5000 mN / 25 mm or more, unintended peeling of the substrate due to twisting, etc. can be prevented. Furthermore, since the T-peel test is designed to simulate the peeling that occurs when opening a confidential postcard, etc., if the peel force in the T-peel test is 1500 mN / 25 mm or less, the substrate can be easily peeled off by hand, etc.

[0029] <Method of manufacturing pseudo adhesive sheet> The pseudo adhesive sheet 1 according to this embodiment can be produced, for example, by a production method including the following steps P1 and P2.

[0030] Step P1 is a step of laminating the second substrate 20 and the pseudo-adhesive layer 30. The laminate produced in step P1, in which the second substrate 20 and the pseudo-adhesive layer 30 are laminated, may be referred to as a "pseudo-adhesive laminate" hereinafter. Step P2 is a step of laminating the first substrate 10 onto the pseudo-adhesive layer 30 of the pseudo-adhesive laminate obtained in step P1.

[0031] ·Process P1 First, step P1 will be described. The method for laminating the pseudo-adhesive layer 30 on the second substrate 20 is not particularly limited. A method for manufacturing the pseudo-adhesive sheet 1 of this embodiment includes, for example, step P1, diluting a pseudo-adhesive layer material containing the material constituting the pseudo-adhesive layer 30 (such as the above-mentioned cellulose acetate) with a solvent and coating it onto the second substrate 20. Methods for coating the pseudo-adhesive layer material onto the second substrate 20 include, for example, spray coating, bar coating, knife coating, roll knife coating, roll coating, blade coating, die coating, and gravure coating.

[0032] ·Process P2 Next, step P2 will be described. In step P2, the first substrate 10 is attached to the surface of the pseudo-adhesive laminate on the pseudo-adhesive layer 30 side by wet lamination or semi-wet lamination while the pseudo-adhesive layer 30 is still wet. Thereafter, drying can be performed to produce the pseudo adhesive sheet 1. The drying conditions can be set as appropriate, but for example, the temperature is 50° C. or higher and 200° C. or lower, and the time is 30 seconds or higher and 5 minutes or lower.

[0033] In this way, by manufacturing using a manufacturing method including steps P1 and P2, a pseudo-adhesive sheet 1 can be manufactured in which the first substrate 10 and the pseudo-adhesive layer 30 are pseudo-adhered to each other at interface A, and the first substrate 10 can be peeled from the pseudo-adhesive layer 30 at interface A.

[0034] <Applications of pseudo adhesive sheets> The pseudo adhesive sheet 1 according to this embodiment can be used as, for example, a confidential postcard, a sealed leaflet, or the like.

[0035] [Effects of this embodiment] The pseudo adhesive sheet 1 according to this embodiment can be easily peeled off by hand while preventing unintended peeling due to kinking of the sheet or the like. [Example]

[0036] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0037] [Preparation of pseudo-adhesive sheet] Example 1 The pseudo adhesive sheet of Example 1 was produced by laminating the first substrate by a wet lamination method (represented as "wet" in Table 1). Specifically, cellulose acetate (L-20, manufactured by Daicel Corporation) with an acetylation degree of 55% was diluted with a solvent (methyl ethyl ketone) to obtain a pseudo-adhesive layer material. This pseudo-adhesive layer material was applied to a paper substrate as a second substrate using an applicator to obtain a pseudo-adhesive laminate. Then, using a hand roller, a surface substrate (thermal paper) as a first substrate was quickly attached to the pseudo-adhesive layer of the pseudo-adhesive laminate, ensuring that the coating did not dry. The resulting mixture was then dried at 70°C for 2 minutes to produce a pseudo-adhesive sheet. The thickness of the pseudo-adhesive layer in the resulting pseudo-adhesive sheet was 6 μm.

[0038] (Examples 2 and 3) For Examples 2 and 3, pseudo-adhesive sheets were produced in the same manner as in Example 1, except that the thickness of the pseudo-adhesive layer was changed. The thickness of the pseudo-adhesive layer in the pseudo-adhesive sheet of Example 2 was 5 μm, and the thickness of the pseudo-adhesive layer in the pseudo-adhesive sheet of Example 3 was 3.5 μm.

[0039] (Comparative Example 1) The pseudo adhesive sheet of Comparative Example 1 was produced by laminating the first substrate by dry lamination (denoted as "dry" in Table 1). Specifically, density 917 kg / m 3 Polyethylene (Novatec (registered trademark) LC8001, manufactured by Japan Polyethylene Co., Ltd.) was heated and melted at 200°C and extruded through a T-die onto a paper substrate as a second substrate to obtain a pseudo-adhesive laminate. Then, a surface substrate (thermal paper) as a first substrate was laminated onto the pseudo-adhesive layer of the pseudo-adhesive laminate to produce a pseudo-adhesive sheet.

[0040] [Evaluation of pseudo adhesive sheets] The pseudo-adhesive sheets produced in Examples 1 to 3 and Comparative Example 1 were evaluated for 180-degree peel strength (pseudo-adhesive strength by 180-degree peeling) and T-peel strength (pseudo-adhesive strength by T-peeling) as follows. The evaluation results are shown in Table 1. The pseudo adhesive strength is measured in mN / 25 mm.

[0041] (180 degree peel strength evaluation) The measurement was made in accordance with 180-degree peel adhesive strength of JIS K6854-2:1999. Specifically, as shown in Fig. 2, the prepared pseudo-adhesive sheet 1 was fixed to a stainless steel test plate 200 with double-sided tape 100. Thereafter, the first substrate 10 of the pseudo-adhesive sheet 1 was peeled from the pseudo-adhesive layer 30 under conditions of a peeling speed of 0.3 m / min and a peeling angle of 180 degrees. The magnitude of the force (peel force) required for this peeling was measured, and the measured peel force was taken as the peel force (pseudo-adhesive force).

[0042] (T-type peel force evaluation) Measurement was carried out in accordance with the T-peel test of JIS K6854-3:1999. Specifically, as shown in Fig. 3, the first substrate 10 of the pseudo-adhesive sheet 1 was peeled off from the pseudo-adhesive layer 30 at a peeling speed of 0.3 m / min. The strength of the force (peel force) required for this peeling was measured, and the measured peel force (peel force) was taken as the pseudo-adhesive force.

[0043] [Table 1]

[0044] As shown in Table 1, the sheet of Comparative Example 1 showed little change in release force depending on the peeling method. In particular, the sheet of Comparative Example 1 had a small release force at 180 degrees, which indicated that there was a risk of the substrate peeling unintentionally. On the other hand, the pseudo-adhesive sheets according to Examples 1 to 3, which had pseudo-adhesive layers containing cellulose acetate, had a T-peel strength comparable to that of the sheet of Comparative Example 1, but a 180-degree peel strength significantly greater than that of the sheet of Comparative Example 1. Therefore, the pseudo-adhesive sheets according to Examples 1 to 3 were pseudo-adhesive sheets that allowed the substrate to be easily peeled off by hand while preventing unintended peeling of the substrate. [Explanation of symbols]

[0045] 1...pseudo adhesive sheet, 10...first substrate, 10A...first substrate surface, 10B...second substrate surface, 20...second substrate, 20A...third substrate surface, 20B...fourth substrate surface, 30...pseudo adhesive layer, 100...double-sided tape, 200...stainless steel test plate, A...interface.

Claims

1. a first substrate; a second substrate; and a pseudo-adhesive layer disposed between the first substrate and the second substrate; the pseudo-adhesive layer comprises cellulose acetate; The pseudo-adhesive layer can be easily peeled off at the interface from at least one of the first substrate and the second substrate, and does not exhibit re-adhesion or re-tackiness after peeling. Pseudo adhesive sheet.

2. the first substrate has a first substrate surface and a second substrate surface opposite the first substrate surface; The first substrate surface is in direct contact with the pseudo-adhesive layer. The pseudo-adhesive sheet according to claim 1 .

3. Printed on the second substrate surface, The pseudo-adhesive sheet according to claim 2 .

4. When the first substrate is peeled from the pseudo-adhesive layer, the pseudo-adhesive sheet peels off at the interface between the first substrate and the pseudo-adhesive layer. The pseudo-adhesive sheet according to claim 2 or 3.

5. The pseudo-adhesive sheet has a peel strength of 5000 mN / 25 mm or more when the first substrate is peeled from the pseudo-adhesive layer at a peel rate of 0.3 m / min in a 180-degree peel test in accordance with JIS K6854-2:1999, and a peel strength of 1500 mN / 25 mm or less when the first substrate is peeled from the pseudo-adhesive layer at a peel rate of 0.3 m / min in a T-peel test in accordance with JIS K6854-3:1999. The pseudo-adhesive sheet according to any one of claims 2 to 4.

6. the second substrate has a third substrate surface on the pseudo-adhesive layer side and a fourth substrate surface opposite to the third substrate surface, Printed on the third substrate surface, The pseudo-adhesive sheet according to any one of claims 1 to 5.

7. The coating amount of the pseudo-adhesive layer is 3 g / m ２ Above, 7g / m ２ Below is the The pseudo-adhesive sheet according to any one of claims 1 to 6.

Images