JP7316821B2 - adhesive film - Google Patents

Description

The present invention relates to adhesive films.

BACKGROUND ART Conventionally, there are pressure-sensitive adhesive films that are attached to adherends to protect their surfaces. For example, Patent Document 1 discloses a paint protection film used in automobiles and the like.

In the above-mentioned prior art, it is disclosed that a film is attached to an exterior material such as a bonnet. Therefore, it is preferable to wind the film to make it compact.

JP 2018-053194 A

However, when the film is wound, the overlapping films may come into close contact with each other, and their slipperiness may be deteriorated. There is a risk of damage.

Accordingly, an object of the present invention is to provide an adhesive film that has good slipperiness even when wound and overlapped.

The pressure-sensitive adhesive film of the present invention for achieving the above object is a roll-shaped pressure-sensitive adhesive film that is attached to an interior material of an automobile and has a substrate layer, a pressure-sensitive adhesive layer, and a release liner in this order in the stacking direction. The arithmetic mean roughness Ra measured in accordance with JIS B0601:2013 (ISO 4287:1997) on one surface of the adhesive film on the release liner side is The arithmetic average roughness Ra of the one surface is greater than the arithmetic average roughness Ra of the other surface, and the arithmetic average roughness Ra of the one surface is 15 nm or more and 41 nm or less . The thickness of the release liner is 3/4 or less of the thickness of the base material layer, and the release liner is arranged on the outer peripheral side in the rolled state.

According to the pressure-sensitive adhesive film having the above structure, even when the pressure-sensitive adhesive films are wound and overlap each other, one of the adjacent surfaces is roughened on the release liner side. It is difficult for them to adhere to each other, and the slip property is good.

It is a side view which shows the adhesive film of embodiment. FIG. 4 is a side view showing the adhesive film in a rolled embodiment; It is a side view which shows the adhesion film of a modification.

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

As shown in FIG. 1, the adhesive film 100 of the embodiment has a base layer 110, an adhesive layer 120, and a release liner 130 in this order in the stacking direction, and one surface 101 on the release liner 130 side. and the other surface 102 on the opposite side thereof have different surface roughnesses.

On the surface 101, the arithmetic mean roughness Ra measured according to JIS B0601:2013 (ISO 4287:1997) is larger than the arithmetic mean roughness Ra on the surface 102, and the surface 101 is roughened. . Specifically, the surface 101 has an arithmetic mean roughness Ra of 15 nm or more. The upper limit of the arithmetic mean roughness Ra on the surface 101 is not particularly limited, but is, for example, 1000 nm.

Further, on the surface 101, the maximum peak height Rp of the roughness curve measured in accordance with JIS B0601:2013 (ISO 4287:1997) is preferably 70 nm or more, and the maximum cross-sectional height of the roughness curve Rt is preferably 130 nm or more.

On the other hand, the surface 102 is smooth, and the arithmetic mean roughness Ra of the surface 102 is, for example, greater than 0 and 10 nm or less.

The base material layer 110 imparts functions according to the application of the pressure-sensitive adhesive film 100, such as conformability to adherends and scratch resistance. The thickness of the base material layer 110 is not particularly limited, but is, for example, 100 μm or more and 150 μm or less.

The material for forming the base material layer 110 is not particularly limited. Vinyl resin, synthetic paper, polyurethane, thermoplastic elastomer, thermoplastic polyolefin, ethylene methacrylic acid copolymer, ionomer, chlorinated polypropylene, fluorinated ethylene-propylene copolymer, polyetherimide and the like. The base material layer 110 may have a single layer structure made of one material, or may have a structure in which a plurality of different layers are laminated.

The adhesive layer 120 is formed from an adhesive that can adhere to an adherend. The adhesive that forms the adhesive layer 120 is not particularly limited, but examples thereof include acrylic adhesives, rubber adhesives, silicone adhesives, polyurethane adhesives, polyester adhesives, and the like. These pressure-sensitive adhesives may be used alone or in combination of two or more.

A release liner 130 is releasably arranged on the pressure-sensitive adhesive layer 120 . The peel force required to peel the release liner 130 from the pressure-sensitive adhesive layer 120 is not particularly limited. That's it.

The thickness of the release liner 130 is not particularly limited, but is, for example, 25 μm or more and 75 μm or less. Moreover, the thickness of the release liner 130 is preferably 1/6 or more and 3/4 or less of the thickness of the base material layer 110 .

The material for forming the release liner 130 is not particularly limited, but examples include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; plastic films such as polyolefin films such as polypropylene and polyethylene; fine paper, glassine paper, and kraft paper. , clay-coated paper, polyethylene-laminated paper obtained by laminating these papers with polyethylene, and polypropylene-laminated paper obtained by laminating these papers with polypropylene.

The manner in which the surface 101 of the release liner 130 is roughened is not particularly limited. Alternatively, one surface of a film made of a single layer of polyethylene terephthalate or the like may be roughened by, for example, sandblasting to form the roughened surface 101 . Alternatively, the release liner 130 may be extruded into a three-layer structure in which the roughened surface 101 is formed by including particles in the outer layer of the three-layer structure. , a single-layer substrate may be coated on one side with a particle-containing coating to form the roughened surface 101 .

The adhesive film 100 is used after peeling off the release liner 130 and is attached to the adherend via the adhesive layer 120 . The adhesive film 100 is attached to an adherend and used to protect the surface of the adherend from scratches, stains, and the like.

The adhesion of the adhesive film 100 to the adherend is, for example, so-called dry adhesion in which the release liner 130 is peeled off and the adhesive layer 120 is adhered to the adherend as it is, but is not limited thereto. After peeling, a so-called wet application may be used in which a working liquid such as a surfactant aqueous solution is sprayed onto at least one of the surface of the pressure-sensitive adhesive layer 120 and the adherend and adhered. In the dry application, for example, the operator uses a spatula called a squeegee to apply the adhesive film 100 to the adherend while pressing it against the adherend. While pressing it, it adheres while removing the construction liquid.

The adhesive film 100 has transparency with the release liner 130 removed. Here, the degree of transparency is not particularly limited as long as the adherend can be visually recognized with the adhesive film 100 attached. For example, the transmittance in the visible light region is 80% or more. , more preferably 90% or more.

In the pressure-sensitive adhesive film 100, if the surface 102 is roughened like the surface 101, the transparency may be lowered. Since it has roughness Ra, the adhesive film 100 has good transparency.

The adherend to which the pressure-sensitive adhesive film 100 is attached includes, for example, an interior material of an automobile, but is not limited to this, and may be an exterior material of an automobile. Also, the adherend is not limited to automobiles, and may be members constituting other moving bodies such as motorcycles, railroad cars, aircraft, and ships.

As shown in FIG. 2, the pressure-sensitive adhesive film 100 is wound into a small roll for use in a narrow space such as the inside of a car in consideration of workability. In such a usage, the adhesive film 100 is positioned by attaching the part 103 where the release liner 130 is partially peeled off to the adherend, and then unfolding and unfolding from the wound state to cover the whole. Affixed to the body. If the adhesive film 100 is wound, it becomes compact, so that it becomes easy to work even in a narrow place.

Next, the effect of this embodiment is described.

When the adhesive films 100 are rolled as shown in FIG. 2, the adhesive films 100 overlap with each other. There is a risk of loss of sexuality.

However, according to the adhesive film 100 of the present embodiment, even if the adhesive films 100 are wound and overlap each other, the surface 101 of the adjacent surfaces 101 and 102 is roughened, so the adhesive film 100 are difficult to adhere to each other, and the slip property is good. Therefore, the adhesive film 100 can be smoothly wound, and the wound adhesive film 100 can be easily unrolled and spread, resulting in excellent workability.

Also, on the surface 101, the maximum peak height Rp of the roughness curve measured in accordance with JIS B0601: 2013 (ISO 4287: 1997) is increased, for example, the maximum peak height Rp is 70 nm or more. For example, the surface 101 can be made rougher by increasing the height of the peaks of the fine irregularities on the surface 101 .

Also, on the surface 101, the maximum cross-sectional height Rt of the roughness curve measured in accordance with JIS B0601:2013 (ISO 4287:1997) is increased, for example, the maximum cross-sectional height Rt is 130 nm or more. , the surface 101 can be further roughened by increasing the difference between the height of the peaks and the depth of the valleys of the fine unevenness of the surface 101 .

When the pressure-sensitive adhesive film 100 is wound, the base layer 110 is deformed into an arc. 130 may be partially peeled off, and a tunnel-shaped float called so-called tunneling may occur.

On the other hand, for example, if the thickness of the release liner 130 is set to be 3/4 or less of the thickness of the base layer 110, the ability of the release liner 130 to follow the deformation of the base layer 110 is enhanced, and tunneling is prevented. easier to suppress.

In addition, the release force required to peel off the release liner 130 is increased. If the angle is 50 mN/50 mm or more at 180°, the release liner 130 is less likely to be peeled off when the substrate layer 110 is deformed, and thus tunneling is easily suppressed.

<Example>
The present inventor actually produced the adhesive films of Examples 1 to 6 and Comparative Examples 1 to 3 having a configuration according to the above embodiment, and examined the slipperiness of the adhesive film when wound and the effect of suppressing tunneling. verified.

Each of the adhesive films of Examples 1 to 6 and Comparative Examples 1 to 3 has a structure in which a base layer, an adhesive layer, and a release liner are laminated in this order, as in the above embodiment. The surface roughness of one side, the release force of the release liner, and the thickness of the release liner were varied in Examples 1-6 and Comparative Examples 1-3.

Regarding the surface roughness of one surface on the release liner side, the present inventors determined that the arithmetic mean roughness Ra, the maximum peak height Rp, and the maximum cross-sectional height Rt was measured.

The present inventor measured the arithmetic mean roughness Ra, the maximum peak height Rp, and the maximum cross-sectional height Rt of each of the adhesive films of Examples 1-6 and Comparative Examples 1-3.

Specifically, the present inventor placed each of the adhesive films of Examples 1 to 6 and Comparative Examples 1 to 3 on the glass plate so that the base layer side surface faced the glass plate side, and double-sided tape and the arithmetic average roughness Ra, the maximum peak height Rp, and the maximum cross-sectional height Rt were measured for one surface on the release liner side using a surface roughness measuring instrument.

The surface roughness measuring machine used at this time is "SV-3000S4" (stylus type) manufactured by Mitutoyo, and the measurement conditions are: measurement length: 10 mm, speed: 1.0 mm / sec, filter type: Gaussian, λ _C : 0.25 mm.

The present inventor measured each of the arithmetic mean roughness Ra, the maximum peak height Rp, and the maximum cross-sectional height Rt 10 times, and calculated the average values for Examples 1 to 6 and Comparative Examples 1 to 3, respectively. The arithmetic mean roughness Ra, the maximum peak height Rp, and the maximum cross-sectional height Rt.

The inventor also measured the peel force required to peel the release liner from the pressure-sensitive adhesive layer according to JIS Z0237:2009 under the conditions of a peel speed of 300 mm/min and a peel angle of 180°.

Table 1 below summarizes the measurement results of the surface roughness, the peel force required to peel off the release liner, and the thickness of the release liner for each of the adhesive films of Examples 1 to 6 and Comparative Examples 1 to 3. . In addition, the same table shows the verification results for slipperiness and tunneling.

With regard to slipperiness and tunneling, the present inventors rolled each of the adhesive films of Examples 1 to 6 and Comparative Examples 1 to 3 into a cylindrical shape having a diameter of about 30 mm, and examined how the adhesive films slide against each other at that time. It was also investigated whether tunneling is effectively suppressed.

In the column of "slipperiness" in Table 1, the verification results of the slipperiness are described. x indicates poor slipperiness.

In addition, in the "Tunneling" column of Table 1, the results of verification of tunneling are described. indicates

As shown in Table 1, in Comparative Examples 1 and 2, the arithmetic mean roughness Ra of one side of the adhesive film on the release liner side was less than 15 nm and the smoothness was high. The adhesive films adhered to each other, resulting in poor slipperiness, and there was some catching between the adhesive films. On the other hand, in Examples 1 to 6, in which the arithmetic mean roughness Ra is 15 nm or more and one surface on the release liner side has moderate roughness, it is difficult for the adhesive films to adhere to each other when wound and overlapped. All of them had good slipperiness. From this result, it can be confirmed that by setting the arithmetic mean roughness Ra to 15 nm or more on one side of the adhesive film on the release liner side, even when the adhesive films are wound and overlapped, good slipperiness can be obtained. rice field.

Further, in Table 1, when Comparative Example 3 is compared with Examples 1 to 6, in Comparative Example 3, in which the release liner is thick, tunneling occurs remarkably, whereas the thickness of the release liner is suppressed. All of Examples 1 to 6 effectively suppressed tunneling.

Whether or not tunneling occurs depends not only on the thickness of the release liner, but also on the thickness of the base material layer (the base material layer bends differently when wound according to its thickness, and the followability of the release liner depends on the thickness of the base material layer). change in ease).

Therefore, in each of Examples 1 to 6, when the ratio of the thickness of the release liner to the thickness of the base material layer (all the base material layers are formed of a polyester-based polyurethane film having a thickness of 150 μm) is obtained, tunneling occurs. In each of Examples 1 to 6 in which the was effectively suppressed, the thickness of the release liner was 3/4 or less of the thickness of the base layer.

On the other hand, in Comparative Example 3, the thickness of the release liner was 150 μm, which was larger than 3/4 of the thickness (150 μm) of the base layer.

From these results, it was confirmed that tunneling can be easily suppressed by setting the thickness of the release liner to 3/4 or less of the thickness of the base material layer.

The present invention is not limited to the embodiments described above, but can be variously modified within the scope of the claims.

For example, the adhesive film 100 of the above-described embodiment comprises a base layer 110, an adhesive layer 120, and a release liner 130, but a form having layers other than these is also included in the scope of the present invention.

As such an example, the modified pressure-sensitive adhesive film 200 shown in FIG. Layer 110, adhesive layer 120, and release liner 130 are laminated in this order.

In the adhesive film 200 of the modified example, as in the above-described embodiment, one surface 101 on the side of the release liner 130 has a larger arithmetic average roughness Ra than the other surface 202 on the opposite side, and is roughened. ing. On the other hand, the other surface 202 on the surface protection layer 240 side is smooth.

The surface protective layer 240 is made of, for example, fluororesin, but the type of resin the surface protective layer 240 is made of is not particularly limited. good.

The surface protective layer 240 has transparency, and the adhesive film 200 has transparency equivalent to that of the adhesive film 100 of the above embodiment with the release liner 130 removed.

Like the pressure-sensitive adhesive film 100 of the above-described embodiment, the form consisting of the base layer 110, the pressure-sensitive adhesive layer 120, and the release liner 130 and having no other layers has a simple structure, so that the manufacturing cost can be reduced.

On the other hand, if the adhesive film 200 of the modified example has the surface protection layer 240, the surface of the adhesive film 200 can be more effectively protected from scratches, stains, and the like.

100, 200 adhesive film,
101 one side of the adhesive film,
102, 202 the other side of the adhesive film,
110 base layer,
120 adhesive layer,
130 release liner,
240 Surface protective layer.

Claims (6)

A roll-shaped adhesive film that is attached to an interior material of an automobile and has a base layer, an adhesive layer, and a release liner in this order in the lamination direction,
The arithmetic mean roughness Ra measured in accordance with JIS B0601:2013 (ISO 4287:1997) on one surface of the adhesive film on the release liner side is larger than the arithmetic mean roughness Ra on the other surface,
The arithmetic mean roughness Ra on the one surface is 15 nm or more and 41 nm or less ,
The thickness of the release liner is 3/4 or less of the thickness of the base layer,
An adhesive film in which the release liner is arranged on the outer peripheral side in a roll state . The peel force required to peel the release liner from the pressure-sensitive adhesive layer is 50 mN/50 mm or more at a peel speed of 300 mm/min and a peel angle of 180° according to JIS Z0237:2009. adhesive film. The pressure-sensitive adhesive film according to claim 1 or 2 , wherein the one surface has a maximum peak height Rp of a roughness curve measured in accordance with JIS B0601:2013 (ISO 4287:1997) of 70 nm or more. Any one of claims 1 to 3 , wherein, on the one surface, the maximum cross-sectional height Rt of the roughness curve measured in accordance with JIS B0601:2013 (ISO 4287:1997) is 130 nm or more. or the pressure-sensitive adhesive film according to one. The pressure-sensitive adhesive film according to any one of claims 1 to 4 , comprising the base material layer, the pressure-sensitive adhesive layer, and the release liner. Having a surface protective layer provided on the base material layer,
The pressure-sensitive adhesive film according to any one of claims 1 to 4 , wherein the surface protective layer, the base layer, the pressure-sensitive adhesive layer, and the release liner are laminated in this order.