JP2005068350A - Adhesive sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive sheet which is used in an advertisement medium or the like, is free from a trouble in external appearance such as swelling, can reduce a wasteful adhesive agent, and needs no special material for the release paper. <P>SOLUTION: The adhesive sheet comprises a sheet having a printable surface, a plurality of adhesive convex regions prepared independently at regular intervals apart from each others on the back surface of the sheet, and a release sheet for covering the surfaces of the convex regions, wherein first grooves formed among the convex regions on the back surface of the sheet are set to have an area ratio of 1:2-1:20 to the sum of the areas of all the convex regions, the neighboring convex regions are set to have an interval of 30-700 μm between them, and the convex regions are set to have a thickness of 10-80 μm. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a pressure-sensitive adhesive sheet, and more particularly to a pressure-sensitive adhesive sheet used by peeling off a release paper and attaching it to an adherend.

  Conventionally, as this kind of pressure-sensitive adhesive sheet, a sheet (base material), a pressure-sensitive adhesive layer laminated on the back surface of the sheet, and a release paper covering the pressure-sensitive adhesive layer are known (for example, see Patent Document 1). .

In this conventional pressure-sensitive adhesive sheet, a plurality of concave portions are formed in advance on one or both sides of the release paper, and the pressure-sensitive adhesive layer is applied and dried on the concave-side surface of the release paper, and then the sheet is laminated on the pressure-sensitive adhesive layer, or It is manufactured by applying and drying an adhesive layer on the back surface of the sheet and then laminating the release paper on the adhesive layer in pressure contact with the surface on the concave side (see, for example, Patent Document 2). Therefore, when the release paper is peeled from the adhesive layer, convex portions formed by a plurality of concave portions of the release paper are formed on the surface of the adhesive layer, and grooves are formed between the convex portions. The groove serves to release air between the adhesive layer and the adherend when the adhesive sheet is attached to an adherend such as a wall or a column.
JP 2001-302999 A Japanese Patent No. 3377439

  However, in the conventional pressure-sensitive adhesive sheet, the pressure-sensitive adhesive layer is laminated on the entire back surface of the sheet, and the portion of the pressure-sensitive adhesive layer corresponding to the groove does not come into contact with the adherend. In addition, in order to form a plurality of recesses on one or both sides of the release paper, the material used as the release paper must be able to hold the shape of the formed recesses for a certain period of time, and a special material is required. It was.

Thus, according to the present invention, a sheet whose surface can be printed, a plurality of adhesive protrusions independently provided at predetermined intervals on the back surface of the sheet, and a release covering the plane of the plurality of protrusions With seats,
The area ratio between the plane area of the first groove portion formed between the convex portions on the back surface of the sheet and the total plane area of all the convex portions is set to 1: 2 to 1:20,
The interval between adjacent convex portions is set to 30 to 700 μm,
An adhesive sheet in which the thickness of the convex part is set to 10 to 80 μm is provided.

  In the pressure-sensitive adhesive sheet of the present invention, since a plurality of adhesive convex portions are independently formed on the back surface of the sheet, there is no adhesive in the portion corresponding to the first groove formed between the convex portions, There is no waste of adhesive. Also, since the release sheet can be a flat sheet that only needs to cover the flat surface of each convex portion, a conventional release sheet having a plurality of concave portions and a special shape that can maintain the shape of such a plurality of concave portions. No release sheet material is required. Further, the area ratio between the planar area of the first groove portion formed between the convex portions on the back surface of the sheet and the total planar area of all the convex portions is set to 1: 2 to 1:20, and adjacent to each other. By setting the interval between the convex portions to 30 to 700 μm and the thickness of the convex portions to 10 to 80 μm, the release sheet is peeled off and the adhesive convex portion is attached to the adherend (for example, a wall or a column). At this time, it is effective to release air from the groove to the outside without generating blistering due to air bubbles (bubbles) between the sheet and the adherend, and to ensure sufficient adhesion to the adherend of the sheet. is there. In addition, when the area ratio, the interval between the convex portions, and the thickness of the convex portions deviate from the above range, it is easy to generate swelling due to the bubbles, and each convex portion is not crushed even by pressing the sheet at the time of pasting, The shape of each convex portion appears on the appearance (surface) of the sheet, which is not preferable.

In the present invention, the sheet (base material) is not particularly limited, and those generally used in the field can be used. For example, paper, plastic sheet, and paper are laminated with a plastic sheet. Synthetic paper and the like. The sheet may be a sheet on which a photograph, picture, character, advertisement content, or the like is printed.
In addition, the material of the adhesive convex portion is not particularly limited, and an acrylic pressure-sensitive adhesive, a rubber pressure-sensitive adhesive or the like generally used in the field can be used. In particular, an acrylic pressure-sensitive adhesive in which the following acrylic resin composition and curing agent are mixed at a blending ratio of 100: 0.4 to 2.0 is preferable. As the acrylic resin composition, molecular weight: about 150,000, composition: 2-ethylhexyl acrylate, vinyl acetate, methacrylic acid or acrylic acid liquidine AR-2420 (manufactured by Big Technos) is preferably used. Further, as the curing agent, composition: tolylene diisocyanate, trimethylolpropane coronate L-55E (urethane resin: manufactured by Nippon Polyurethane Co., Ltd.), liquidyne HD107 (aluminum chelate: manufactured by Big Technos), liquidine HD5060 (epoxy resin: Big Technos) and the like are preferably used.
Further, the shape of the convex portion is not particularly limited, and examples thereof include a triangle, a quadrangle, a hexagon, a circle, an ellipse, and the like. ) Is preferably uniform and arranged in a matrix form so as not to cause uneven adhesion.
Further, the release sheet is not particularly limited, and those generally used in the field can be used. For example, paper, plastic sheet, laminated sheet obtained by laminating paper with a plastic sheet, etc. Examples include a release surface coated with a release agent that improves the releasability from the adhesive convex portion.

In the present invention, as described above, the surface area of the convex portion is 0.5 to 25 mm ² , preferably 0.5 to 25 mm ² in order to prevent swelling due to air accumulation and to secure sufficient adhesive force. It is good to set.

The pressure-sensitive adhesive sheet of the present invention may be one in which a plurality of convex portions are arranged in a matrix and the second grooves are formed on the planes of the plurality of convex portions and on a plurality of parallel virtual straight lines. Good. For example, when a plurality of protrusions are arranged vertically and horizontally, a second groove is formed on each of a plurality of parallel vertical virtual straight lines that pass through the centers of the protrusions, or a plurality of protrusions that pass through the centers of the protrusions. A second groove is formed on each parallel horizontal virtual straight line, a second groove is formed on each of a plurality of parallel oblique virtual straight lines passing through the center of each convex portion, or these vertical and horizontal lines are formed. The oblique second groove may be combined.
In this way, when the sheet is attached, the air can flow in a straight line direction when the surface of the sheet is rubbed with a hand or a squeegee and the air on the back side is pushed out. it can. This will be described in detail in Examples.
Embodiments of the present invention will be described below in detail with reference to the drawings. In addition, this invention is not limited to an Example.

  FIG. 1 is a partially enlarged cross-sectional view showing the pressure-sensitive adhesive sheet of Example 1 of the present invention, and FIG. 2 is a plan view showing a part of the pressure-sensitive adhesive sheet of Example 1, showing the back surface excluding the release sheet. ing.

  The pressure-sensitive adhesive sheet 1 includes a sheet 2 made of synthetic paper and having a thickness of 100 μm, a plurality of pressure-sensitive adhesive protrusions 3 made of an acrylic pressure-sensitive adhesive independently provided at a predetermined interval on the back surface of the sheet 2, and the plurality The release sheet 4 is made of PET resin and has a thickness of 38 μm that covers the surface of the projection 3.

The adhesive convex part 3 is formed in a flat regular hexagon, and is arranged in a honeycomb shape on the back surface of the sheet 2, whereby a honeycomb-shaped first groove 5 is formed between the convex parts 3. . Further, the thickness T of the convex portion 3 is about 30 μm, the planar area is about 0.9 mm ² , and the interval L between the adjacent convex portions 3 and 3 is about 300 μm. Further, the area ratio between the planar area of the first groove 5 portion formed between the convex portions 3 on the back surface of the sheet 2 and the planar total area of all the convex portions 3 is set to 1: 4. .

  In order to form the plurality of adhesive convex portions 3 on the back surface of the sheet 2, the adhesive sheet 1 can be subjected to the following manufacturing process. For example, an adhesive is filled in each concave portion of a first roll formed by arranging a plurality of concave portions on the outer peripheral surface in a matrix, and the first roll that rotates and the second roll that rotates in opposition thereto are rotated. By continuously transferring the sheet 2 between the rolls, the pressure-sensitive adhesive filled in the respective recesses of the first roll is transferred to the back surface of the sheet 2, and the pressure-sensitive adhesive is dried to some extent. A plurality of convex portions 3 can be formed in a matrix on the back surface. In addition, the peeling sheet 4 is piled up and coat | covered on the plane of each convex part 3 after that.

  As a method of filling an adhesive in each recess of the first roll, an adhesive having a certain degree of fluidity is applied in a curtain shape on the outer peripheral surface of the first roll and filled in each recess, A method of scraping off the excess adhesive applied between the recesses with a blade, or by placing the application roll facing the first roll and rotating it with the application roll immersed in the adhesive in the container A method of filling the adhesive on the outer peripheral surface of the coating roll into the respective recesses of the first roll is mentioned. In the latter case, if excess adhesive is applied to the first roll, it may be scraped off with a blade in the same manner as the former.

  FIG. 3 is a plan view showing a part of the pressure-sensitive adhesive sheet of Example 2 of the present invention, and shows the back surface excluding the release sheet. In the pressure-sensitive adhesive sheet 10 of Example 2, second grooves are respectively formed on the planes of hexagonal convex portions arranged in a matrix of the pressure-sensitive adhesive sheet of Example 1 and on a plurality of parallel virtual straight lines. The sheet and release sheet are provided in the same manner as in Example 1. In FIG. 3, the same reference numerals are given to the first grooves which are the same elements as in the first embodiment. In addition, one of the hexagonal portions is provided with a horizontal stripe so that it can be easily understood.

  More specifically, in the second embodiment, the plurality of parallel virtual straight lines are parallel virtual straight lines A1, A2, A3,..., Parallel virtual straight lines B1, B2, B3,. C1, C2, C3,..., And three second grooves 15 are formed in a region connecting the diagonals of the hexagonal convex portions. Thus, by forming the three second grooves 15 on the hexagonal convex portion, one convex portion is divided into six small triangular small convex portions 13. In this case, the width of the second groove 15 is set to be approximately equal to the width of the first groove 5 (interval L between adjacent convex portions 3 and 3 in Example 1). In addition, the area ratio between the plane total area of the first groove 5 and the second groove 15 and the plane total area of all the small convex portions 13 is set to 1: 3.5.

  Since the first groove 5 and the second groove 15 communicate with each other on the imaginary straight line, the pressure-sensitive adhesive sheet of Example 2 configured as described above is attached to the sheet when the sheet is attached to the adherend. The air between the body can be released in a linear direction, and the swelling of the sheet due to remaining bubbles can be more effectively prevented.

FIG. 4 is a plan view showing a part of the pressure-sensitive adhesive sheet of Example 3 of the present invention, and shows the back surface excluding the release sheet. The pressure-sensitive adhesive sheet 20 of Example 3 is obtained by making the planar shape of the convex portion of the pressure-sensitive adhesive sheet of Example 1 circular, and includes a sheet and a release sheet as in Example 1. In the case of Example 3, the thickness of the convex portion 23 is about 30 μm, the planar area is about 3.1 mm ² , and the interval L3 (the closest portion) between the adjacent convex portions 23 and 23 is about 200 μm. It is. Further, the area ratio between the planar area of the first groove 25 portion formed between the convex portions 23 on the back surface of the sheet and the total planar area of all the convex portions 23 is set to 1: 3. In FIG. 4, reference numeral 25 denotes a first groove.

  FIG. 5 is a plan view showing a part of the pressure-sensitive adhesive sheet of Example 4 of the present invention, and shows the back surface excluding the release sheet. The pressure-sensitive adhesive sheet 30 of this Example 4 is formed by forming the second groove 35 at a central angle of 60 ° on the plane of the circular protrusions arranged in the matrix of the pressure-sensitive adhesive sheet of Example 3 described above. The convex portion is divided into six small fan-shaped small convex portions 33. In other words, the second grooves 35 are formed on three imaginary straight lines (not shown) that extend radially at the center angle of 60 ° at the center of each circular convex portion, and communicate with the first grooves 25. In this case, the width of the second groove 35 is set to be approximately equal to the width of the first groove 25 (interval L3 between the adjacent protrusions 3 and 3 in the third embodiment). In addition, the area ratio between the plane total area of the first groove 25 and the second groove 35 and the plane total area of all the small protrusions 33 is set to 1: 2.5.

  Next, in the adhesive sheet having the structure described in Example 1, the planar area of the first groove 5 portion formed between the convex portions 3 on the back surface of the sheet 2 and the total planar area of all the convex portions 3 Are prepared, and test pieces 1 to 9 having different thickness ratios, widths of the first grooves 5 (intervals between adjacent convex portions), and thicknesses of the convex portions 3 are prepared, and the sheets of the respective adhesive sheets are adhered. After that, the swelling evaluation and the appearance evaluation were performed, and the results are shown in Table 1. A 30 cm × 30 cm polycarbonate plate was used as the adherend, and a squeegee was used for pasting. Hereinafter, the test method is as follows.

[Test Method 1]
A sheet of each pressure-sensitive adhesive sheet was attached to an adherend and left at room temperature of 80 ° C. for 24 hours to determine whether the sheet was swollen. The method for judging the swelling is indicated by ◎ ○ △ × in Table 1. ◎: 10 or less blisters of 1 mm or less, ○: 10 or less blisters of 5 mm or less, Δ: 10 or less blisters of 10 mm or less Generation, x: 11 or more blisters exceeding 10 mm were generated.

[Test Method 2]
A sheet of each pressure-sensitive adhesive sheet was attached to an adherend, and it was determined whether or not the shape of each convex portion could be seen by looking at the appearance (surface) of the sheet. The determination method is indicated by ○ × in Table 1, ○: the shape of the convex portion is not known, Δ: the shape of the convex portion is slightly understood, and X: the shape of the convex portion is clearly understood.

As a result of the test, as shown in Table 1, the area ratio (convex / groove) is 5 times (within a range of 2 to 20 times), and the width of the first groove is 150 μm, 350 μm, 550 μm (30 to 700 μm). Specimens 1 to 4 in which the thickness of the convex portion is 30 μm (within a range of 10 to 80 μm) were generally evaluated as bulges, and the appearance evaluations were all “good”.
On the other hand, the test body 5 had an area ratio (convex / groove) of 1.5 times (smaller than 2 times) and an appearance evaluation of x. This is presumably because the groove occupied area is too large, so that the groove remains and the contour of the protrusion remains even if the protrusion is crushed.
The test body 6 had a groove width of 25 μm (smaller than 30 μm) and a swelling evaluation of x. This is presumably because the groove width is too small and air is difficult to escape and remains.
The test body 7 had a groove width of 750 μm (greater than 700 μm), and the appearance evaluation was x. This seems to be because the groove width is too large and the groove remains and the contour of the convex portion remains even if the convex portion is crushed.
The test body 8 had a convex thickness of 100 μm (greater than 80 μm), and both swelling evaluation and appearance evaluation were triangular. This is probably because the thickness of the convex portion is slightly too thick, and even if the convex portion is crushed, a gap is likely to remain between the grooves.
The test body 9 had an area ratio of 50 times (over 20 times), and the swollen evaluation was x. This seems to be because the occupied area of the convex portion is too large, and it is difficult for air to escape from the groove.

  In this way, if the pressure-sensitive adhesive sheet (test bodies 1 to 4) has all of the area ratio, the groove width (interval between adjacent convex portions), and the thickness of the convex portion within the range defined by the present invention, the swelling is obtained. Since the evaluation and the appearance evaluation are good, it is suitable for use as an advertising medium that can be seen by the human eye. Contrary to this, any one of the area ratio, the groove width (interval between adjacent convex portions), and the thickness of the convex portion deviated from the range defined by the present invention (test bodies 5 to 9). Left problems with blistering and / or appearance.

It is a partial expanded sectional view which shows the adhesive sheet of Example 1 of this invention. It is a top view which shows a part of adhesive sheet of the Example 1, Comprising: The back surface except a peeling sheet is represented. It is a top view which shows a part of adhesive sheet of Example 2 of this invention, Comprising: The back surface except a peeling sheet is represented. It is a top view which shows a part of adhesive sheet of Example 3 of this invention, Comprising: The back surface except a peeling sheet is represented. It is a top view which shows a part of adhesive sheet of Example 4 of this invention, Comprising: The back surface except a peeling sheet is represented.

Explanation of symbols

1, 10, 20, 30 Adhesive sheet 2 Sheet (base material)
3, 13, 23, 33 Convex part 4 Release sheet 5, 15, 25 First groove L, L3 Interval T Thickness A1, A2, A3, B1, B2, B3, C1, C2, C3 Virtual straight line 15, 35 First 2 grooves

Claims (5)

A sheet on which the front surface can be printed, a plurality of adhesive protrusions independently provided at predetermined intervals on the back surface of the sheet, and a release sheet that covers the plane of the plurality of protrusions,
The area ratio between the plane area of the first groove portion formed between the convex portions on the back surface of the sheet and the total plane area of all the convex portions is set to 1: 2 to 1:20,
The interval between adjacent convex portions is set to 30 to 700 μm,
A pressure-sensitive adhesive sheet, wherein the thickness of the convex portion is set to 10 to 80 μm. The pressure-sensitive adhesive sheet according to claim 1, wherein a planar area of the convex portion is 0.5 to 25 mm ² . The pressure-sensitive adhesive sheet according to claim 1 or 2, wherein the plurality of convex portions are arranged in a matrix, and further, second grooves are formed on the planes of the plurality of convex portions and on a plurality of parallel virtual straight lines. The pressure sensitive adhesive sheet according to claim 3 whose width of the 2nd slot is 30-700 micrometers. The pressure-sensitive adhesive sheet according to any one of claims 1 to 4, wherein the convex portion has a flat surface formed in a hexagonal shape.

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