JP2022043551A - Adhesive sheet and adhesive sheet production method - Google Patents

Abstract

[Problem] To provide an adhesive sheet and an adhesive sheet manufacturing method in which the uneven shape of the release liner is difficult to visually see as if it were raised on the surface of the adhesive sheet. [Solution] An adhesive sheet (100) has a base layer (110), an adhesive layer (120), and a release liner (130), in that order in the stacking direction, with uneven shapes (131) formed on the surface of the release liner facing the adhesive layer, and the 60-degree specular gloss of one surface (111) facing the base layer, measured in accordance with JIS Z 8741, is 30% or less. [Selected Figure] Figure 1

Description

The present invention relates to an adhesive sheet and a method for producing an adhesive sheet.

Conventionally, in order to prevent the pressure-sensitive adhesive sheet attached to an adherend from swelling, a release liner having an uneven surface has been used, for example, as disclosed in Patent Document 1.

The release liner having an uneven shape is used by being laminated with the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet, and the uneven shape of the release liner is transferred to the pressure-sensitive adhesive layer. As a result, a recess for allowing air to escape is formed in the pressure-sensitive adhesive layer, so that the pressure-sensitive adhesive sheet can prevent swelling when it is attached to the adherend via the pressure-sensitive adhesive layer.

Japanese Unexamined Patent Publication No. 2010-058395

However, when a release liner having an uneven shape is used on an adhesive sheet having a relatively strong surface gloss, the uneven shape of the release liner may be visually recognized as being raised on the surface of the adhesive sheet.

It is considered that this is because the base material layer of the pressure-sensitive adhesive sheet is deformed according to the uneven shape of the release liner, and such deformation becomes conspicuous in the pressure-sensitive adhesive sheet having a relatively strong surface gloss.

If the uneven shape of the release liner is visually recognized as being raised on the surface of the adhesive sheet, the adhesive sheet such as a decorative film may impair the design, which is not preferable.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a pressure-sensitive adhesive sheet and a method for manufacturing a pressure-sensitive adhesive sheet, in which the uneven shape of the release liner is hard to be visually recognized as if it is raised on the surface of the pressure-sensitive adhesive sheet.

The pressure-sensitive adhesive sheet of the present invention for achieving the above object has a base material layer, a pressure-sensitive adhesive layer, and a release liner in this order in the stacking direction, and the surface of the release liner on the pressure-sensitive adhesive layer side has irregularities. The shape is formed, and the 60-degree mirror surface gloss measured in accordance with JIS Z 8741 on one surface on the substrate layer side is 30% or less.

In the method for producing an adhesive sheet of the present invention for achieving the above object, a sheet base material having a surface having a 60-degree mirror surface gloss measured in accordance with JIS Z 8741 having a surface gloss of 30% or less is prepared, and a surface thereof is prepared. A release liner having an uneven shape is prepared, the pressure-sensitive adhesive composition is applied to at least one of the sheet base material and the release liner, and the sheet base material and the release liner are bonded to each other. At the time of mating, the surface of at least one of both surfaces having the 60-degree mirror gloss of 30% or less is directed to the side opposite to the release liner, and the release liner has the unevenness. The surface on which the shape is formed is directed toward the sheet substrate.

According to the invention having the above configuration, since the gloss of the surface of the adhesive sheet is suppressed, even if the base material layer of the adhesive sheet is deformed according to the uneven shape of the release liner, such deformation is inconspicuous and the release liner is not noticeable. It is possible to prevent the uneven shape of the adhesive sheet from being visually recognized as being raised on the surface of the adhesive sheet.

It is a side view of the adhesive sheet of an embodiment. It is a side view of the adhesive sheet of embodiment which peeled off the release liner. It is a top view of the release liner. It is a figure which shows the outline of the adhesive sheet manufacturing method of an embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the attached drawings. The dimensional ratios in the drawings are exaggerated for convenience of explanation and differ from the actual ratios.

As shown in FIG. 1, the pressure-sensitive adhesive sheet 100 of the embodiment has a base material layer 110, a pressure-sensitive adhesive layer 120, and a release liner 130 in this order in the stacking direction. The adhesive sheet 100 is, for example, a decorative film for decorating an adherend. The adherend to which the adhesive sheet 100 is attached is, for example, a vehicle such as a four-wheeled vehicle or a two-wheeled motorcycle, but is not limited thereto. The present invention may be attached to an adherend other than a vehicle, and its intended use is not particularly limited. The adhesive sheet 100 may be used, for example, as a mark or a sticker, or may be used as a substitute for a striped tape or a coating.

The pressure-sensitive adhesive sheet 100 has a 60-degree mirror surface gloss measured in accordance with JIS Z 8741 on one surface 111 on the base material layer 110 side, which is greater than 0% and 30% or less. For example, the mirror glossiness can be suppressed by making the surface 111 rough, but how to suppress the mirror glossiness of the surface 111 is not particularly limited. Further, examples of the method of roughening the surface 111 include, but are not limited to, a method of embossing the base material layer 110 and a method of incorporating a filler in the base material layer 110.

The base material layer 110 preferably has good followability to an adherend having many curved surfaces such as a vehicle such as a four-wheeled vehicle or a two-wheeled motorcycle, and is formed of, for example, a vinyl chloride resin. Examples of the vinyl chloride-based resin include polyvinyl chloride, vinyl chloride monomers, and copolymers with other monomers copolymerizable with the vinyl chloride monomer. The material for forming the base material layer 110 is not limited to these, and may be another resin material such as an acrylic resin, a urethane resin, or a fluorine resin.

Further, the base material layer 110 may have various types such as a plasticizer, an antioxidant, an ultraviolet absorber, a light stabilizer, a flame retardant, an antistatic agent, a foaming agent, a lubricant, a filler, and a colorant, if necessary. Additives can be included. The thickness of the base material layer 110 is, for example, 10 μm to 300 μm, but is not limited thereto.

The base material layer 110 is colored to prevent the pressure-sensitive adhesive layer 120 from being visually recognized from the base material layer 110 side. In the present embodiment, the base material layer 110 itself is colored by impregnating the base material layer 110 with a colorant, but the present invention is not limited to this embodiment. For example, a form in which at least one of both surfaces of the base material layer 110 is colored is also included in the scope of the present invention.

Further, the base material layer 110 is not limited to a plain form as in the present embodiment, and may be provided with, for example, a pattern, letters, numbers, symbols, or the like. These may be provided on the base material layer 110 itself, or may be provided on at least one of both sides of the base material layer 110, for example, by forming a print layer.

The pressure-sensitive adhesive layer 120 is formed of, for example, an acrylic pressure-sensitive adhesive, a rubber-based pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive, a polyurethane-based pressure-sensitive adhesive, a polyester-based pressure-sensitive adhesive, or the like, and the material for forming the pressure-sensitive adhesive layer 120 is these. Not limited to. The thickness of the pressure-sensitive adhesive layer 120 is, for example, 5 μm to 100 μm, but is not limited thereto.

The release liner 130 is removably arranged on the surface of the pressure-sensitive adhesive layer 120. The release liner 130 has a structure in which a thermoplastic resin such as polyethylene is laminated on a paper base material such as high-quality paper, glassine paper, or coated paper, and a release agent layer made of a release agent such as silicone is provided. However, it is not limited to such a configuration. The thickness of the release liner 130 is, for example, 30 μm to 180 μm, but is not limited thereto.

As shown in FIG. 2, the release liner 130 has an uneven shape 131 formed by the ridges 132 on the surface on the pressure-sensitive adhesive layer 120 side. The various dimensions of the concave-convex shape 131 are not particularly limited, but the convex height L1 (or concave depth) is, for example, 7 μm or more and 20 μm or less, and the convex width L2 is, for example, 50 μm or more and 70 μm or less, between the convex parts. The interval L3 is, for example, 400 μm or more and 650 μm or less. The uneven shape 131 is inverted and transferred to the pressure-sensitive adhesive layer 120, whereby a recess 121 is formed in the pressure-sensitive adhesive layer 120.

Since the recess 121 is formed in the pressure-sensitive adhesive layer 120, when the pressure-sensitive adhesive sheet 100 is attached to the adherend via the pressure-sensitive adhesive layer 120, air is interposed between the pressure-sensitive adhesive layer 120 and the adherend. Even so, air is released by the recess 121, and the swelling of the adhesive sheet 100 is suppressed.

In the present embodiment, the ridge portion 132 has a triangular cross-sectional shape, but the ridge portion 132 is, for example, a rectangular cross-sectional shape, a mountain-shaped cross-sectional shape with rounded apex, and a semicircle. It may have other cross-sectional shapes such as the cross-sectional shape of. The ridge portion 132 is formed, for example, by embossing the surface of the release liner 130, but how the ridge portion 132 is formed is not particularly limited.

As shown in FIG. 3, the ridge portion 132 extends in the plane direction on the surface of the release liner 130. In the present embodiment, a plurality of linearly extending ridge portions 132 intersect in a mesh pattern, but the present embodiment is not limited to this embodiment. A plurality of linearly extending ridges 132 may be provided in parallel without intersecting each other. Further, the ridge portion 132 may be curved in a curved shape.

Next, the method for manufacturing the pressure-sensitive adhesive sheet according to the embodiment will be described.

As shown in FIG. 4, in the pressure-sensitive adhesive sheet manufacturing method of the present embodiment, a sheet base material 110A, which is the same material as the base material layer 110 and is the source thereof, and a release liner 130 are prepared, and the release liner 130 has an adhesive composition. After the object 120A is coated, the sheet base material 110A and the release liner 130 are bonded to each other.

The sheet base material 110A has a surface 111A having a 60-degree mirror surface gloss measured in accordance with JIS Z 8741 of more than 0% and 30% or less. The sheet substrate 110A may have a 60-degree mirror gloss of 30% or less on at least one of the two surfaces, and the 60-degree mirror gloss of 30% or less on both the surface 111A and the opposite surface. It may be present, or the 60-degree mirror surface gloss may be 30% or less only on one surface 111A. When the sheet base material 110A is attached to the release liner 130, the surface 111A is directed to the side opposite to the release liner 130.

In the release liner 130, the pressure-sensitive adhesive composition 120A is applied to the surface on which the uneven shape 131 is formed, and the same surface is directed toward the sheet base material 110A and bonded. The pressure-sensitive adhesive composition 120A is coated by, for example, a knife coater, but the method of coating is not particularly limited, and may be, for example, a die coater, a curtain coater, or the like.

The pressure-sensitive adhesive composition 120A contains a pressure-sensitive adhesive and a cross-linking agent. The cross-linking agent is not particularly limited, and examples thereof include an isocyanate-based cross-linking agent, an epoxy-based cross-linking agent, and a metal chelate-based cross-linking agent. These cross-linking agents may be used alone or in combination of two or more.

Further, the pressure-sensitive adhesive composition 120A may contain additives such as a plasticizer, a filler, an antistatic agent, an anti-blocking agent, a light stabilizer, and a colorant. Further, when applying to the release liner 130, a solvent may be added to the pressure-sensitive adhesive composition 120A to adjust the viscosity.

After coating the pressure-sensitive adhesive composition 120A, the pressure-sensitive adhesive composition 120A is cured to form the pressure-sensitive adhesive layer 120. How the pressure-sensitive adhesive composition 120A is cured is not particularly limited, and may be cured by heating, for example. Further, in addition to such a form, for example, a form in which the pressure-sensitive adhesive composition 120A is cured by irradiation with light is also included in the scope of the present invention.

After the pressure-sensitive adhesive layer 120 is formed on the release liner 130, the laminated body thereof and the sheet base material 110A are bonded to each other via the pressure-sensitive adhesive layer 120 to produce a pressure-sensitive adhesive sheet 100.

In the present embodiment, the pressure-sensitive adhesive sheet 100 is produced by laminating the laminate of the pressure-sensitive adhesive layer 120 and the release liner 130 with the sheet base material 110A, but the present invention is not limited to this embodiment. For example, the pressure-sensitive adhesive composition 120A is applied to the surface of the sheet base material 110A on the side opposite to the surface 111A and cured to form a laminate of the sheet base material 110A and the pressure-sensitive adhesive layer 120. The pressure-sensitive adhesive sheet 100 may be produced by laminating the laminate and the release liner 130.

Next, the action and effect of this embodiment will be described.

Before bonding the sheet base material 110A and the release liner 130, the sheet base material 110A has a relatively flat surface as compared with the uneven shape 131 of the release liner 130, but the sheet base material 110A and the release liner 130 have a relatively flat surface. When the base material layer 110 is formed by the bonding with the base layer 110, the base material layer 110 may be deformed according to the uneven shape 131 of the release liner 130.

Specifically, in the pressure-sensitive adhesive sheet 100 of the present embodiment, the surface 111 of the base material layer 110 is convex at the portion where the ridge portion 132 of the release liner 130 is provided, and the convex portions are concave. What kind of deformation occurs on the surface 111 is not limited to the shape disclosed in this embodiment, and differs depending on the uneven shape 131 of the release liner 130.

Such deformation that occurs in the base material layer 110 is conspicuous when the surface 111 has a strong gloss unlike the present embodiment, and as a result, the uneven shape 131 of the release liner 130 is visually recognized as embossing on the surface of the adhesive sheet 100. There are times. More specifically, when the surface 111 has a strong gloss, a mesh pattern similar to that shown in FIG. 3 may be visually recognized on the surface of the adhesive sheet 100.

On the other hand, in the present embodiment, the 60-degree mirror surface gloss measured on the surface 111 in accordance with JIS Z 8741 is 30% or less, and the gloss is suppressed, so that the surface 111 corresponds to the uneven shape 131 of the release liner 130. Even if the base material layer 110 is deformed, such deformation is inconspicuous, and it is possible to prevent the uneven shape 131 of the release liner 130 from being visually recognized as being raised on the surface of the pressure-sensitive adhesive sheet 100.

Further, a pattern formed on the surface of the pressure-sensitive adhesive layer 120 by the recesses 121 formed in the pressure-sensitive adhesive layer 120, specifically, a mesh pattern similar to that shown in FIG. 3 in the above embodiment is formed on the base material layer 110 side. If it can be seen through, the appearance of the adhesive sheet 100 may be impaired.

However, in the present embodiment, the colored base material layer 110 blocks the adhesive layer 120 from being visually recognized from the base material layer 110 side, so that a pattern is formed on the surface of the pressure-sensitive adhesive layer 120 by the recess 121. Even if such a pattern is formed, such a pattern cannot be seen through from the base material layer 110 side, and it is possible to prevent the appearance of the adhesive sheet 100 from being impaired.

In the present embodiment, since the ridge portion 132 extends in the surface direction, the recess 121 that is inverted and transferred is formed in a groove shape that extends in the surface direction of the pressure-sensitive adhesive layer 120. As a result, when the adhesive sheet 100 is attached to the adherend, the air interposed between the adherend and the adhesive layer 120 is smoothly released in the surface direction. Therefore, according to the present embodiment, the adhesive is adhered. The blistering of the sheet 100 can be effectively suppressed.

Next, an embodiment will be described.

<Example>
The present inventor actually produced the pressure-sensitive adhesive sheets of Examples 1 to 3 according to the above-described embodiment, and also produced the pressure-sensitive adhesive sheets of Comparative Examples 1 to 3 as comparison targets. , It was confirmed whether or not it was visually recognized so as to stand out on the surface of the adhesive sheet.

The pressure-sensitive adhesive sheets of Examples 1 to 3 and Comparative Examples 1 to 3 each have a structure in which a base material layer, a pressure-sensitive adhesive layer, and a release liner are laminated in this order. In the pressure-sensitive adhesive sheets of Examples 1 to 3 and Comparative Examples 1 to 3, the 60-degree mirror surface gloss measured according to JIS Z 8741 is different on the surface on the substrate layer side. The mirror glossiness was measured using a gloss meter VG7000 manufactured by Nippon Denshoku Industries Co., Ltd.

The release liner used in Examples and Comparative Examples has a structure in which a polyethylene layer is provided on the surface of a paper base material, and an uneven shape is formed on the surface provided with the polyethylene layer by embossing. Has been done. In the same uneven shape, the various dimensions corresponding to the uneven shape 131 of the release liner 130 shown in FIG. 2 are that the convex height L1 (or the concave depth) is 10 μm, the convex width L2 is 65 μm, and the distance between the convexes. The interval L3 is 600 μm.

The pressure-sensitive adhesive composition was applied to the surface of the release liner provided with such an uneven shape at a coating amount of 25 g / m ² to form a pressure-sensitive adhesive layer having a thickness of about 23 μm. The substrate layers of the pressure-sensitive adhesive sheets of Examples and Comparative Examples are all formed of polyvinyl chloride. Further, the base material layer of the pressure-sensitive adhesive sheets of Examples 1 to 3 and Comparative Examples 1 and 2 has a thickness of 50 μm, and the base material layer of the pressure-sensitive adhesive sheet of Comparative Example 3 has a thickness of 80 μm.

The present inventor prepared a pressure-sensitive adhesive sheet by laminating a release liner coated with the pressure-sensitive adhesive composition and a sheet base material which is a base material layer, and stored the pressure-sensitive adhesive sheet at 23 ° C. for 24 hours. By observing from the base material layer side, it was confirmed whether or not the uneven shape of the release liner was visually recognized so as to stand out on the surface of the adhesive sheet. The evaluation results are shown in Table 1 below.

In the evaluation results of Table 1, ⊚ indicates that the effect of preventing the uneven shape of the peeling liner from being visually recognized is particularly excellent, ○ indicates that the effect is good, and × indicates that the uneven shape of the peeling liner is an adhesive sheet. It means that it is visually recognized as if it stands out on the surface of.

As shown in Table 1, in the adhesive sheets of Comparative Examples 2 and 3 having a large mirror surface gloss and a strong surface gloss, the uneven shape of the release liner is visually recognized so as to stand out on the surface of the adhesive sheet, and is shown in FIG. A mesh pattern like that was confirmed on the surface of the adhesive sheet.

On the other hand, in the pressure-sensitive adhesive sheet of Comparative Example 1 having a relatively weak gloss, the uneven shape of the release liner was not clearly visible as in Comparative Examples 2 and 3, and the influence on the appearance was suppressed.

Further, in Examples 1 to 3 in which the mirror glossiness was small and the gloss was suppressed, the uneven shape of the release liner was not visually recognized on the surface of the adhesive sheet, and the original appearance of the adhesive sheet was maintained well. ..

From these facts, it is possible to prevent the uneven shape of the release liner from being visually recognized as appearing on the surface of the adhesive sheet by suppressing the gloss so that the mirror glossiness of the surface of the adhesive sheet is equal to or less than a predetermined value. It could be confirmed.

The present invention is not limited to the above-described embodiments and examples, and various modifications can be made within the scope of the claims. For example, the pressure-sensitive adhesive sheet 100 of the above embodiment has a structure in which a base material layer 110, a pressure-sensitive adhesive layer 120, and a release liner 130 are laminated, but a form having other layers is also included in the scope of the present invention. Is done.

Further, the shape of the adhesive sheet is not particularly limited, and may be, for example, a long shape, a rectangular shape, a circular shape, an elliptical shape, or the like, or an irregular shape such as a contour of a character or a character. It may be in the shape of.

100 adhesive sheet,
110 base material layer,
110A sheet base material,
111 One side of the pressure-sensitive adhesive sheet on the base material layer side,
111A Sheet substrate surface,
120 adhesive layer,
120A Adhesive Composition,
121 recess,
130 peeling liner,
131 Concavo-convex shape,
132 ridges.

Claims (6)

A pressure-sensitive adhesive sheet having a base material layer, an adhesive layer, and a release liner in this order in the stacking direction, and having an uneven shape formed on the surface of the release liner on the pressure-sensitive adhesive layer side.
An adhesive sheet having a 60-degree mirror surface gloss measured in accordance with JIS Z 8741 on one surface of the base material layer side of 30% or less. The pressure-sensitive adhesive sheet according to claim 1, wherein the colored base material layer prevents the pressure-sensitive adhesive layer from being visually recognized from the base material layer side. The pressure-sensitive adhesive sheet according to claim 1 or 2, wherein the uneven shape of the release liner is formed by a ridge portion extending in the surface direction. A sheet base material having a surface having a 60-degree mirror surface gloss measured in accordance with JIS Z 8741 of 30% or less is prepared, and the sheet substrate is prepared.
Prepare a release liner with an uneven shape on the surface,
The pressure-sensitive adhesive composition is applied to at least one of the sheet base material and the release liner, and the sheet base material and the release liner are bonded together.
At the time of the bonding
In the sheet base material, at least one of the two surfaces having the 60-degree mirror gloss of 30% or less is directed to the side opposite to the release liner.
The release liner is a method for manufacturing an adhesive sheet in which the surface on which the uneven shape is formed is directed toward the sheet base material. The adhesive sheet manufacturing method according to claim 4, wherein the sheet base material is colored and the visibility from one surface to the other surface is blocked. The adhesive sheet manufacturing method according to claim 4 or 5, wherein the release liner having the uneven shape formed by the ridges extending in the surface direction is used.

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