TW202411070A - Cover film-attached pressure-sensitive adhesive layer - Google Patents

Abstract

To provide an adhesive layer with a cover film, which is suitable for suppressing end adhesion and adhesive contamination. An adhesive layer (X) with a cover film, which is provided with a cover film (10), an adhesive layer (30), and a cover film (20) in this order in the thickness direction (H). The cover film (10) has a first surface (11) on the adhesive layer (30) side, and has a film end surface (12) that forms an acute angle with the first surface (11). The cover film (20) has an extended end portion (20A). The protruding end portion (20A) protrudes further outward than the end portion (30A) of the adhesive layer (30) in a plane direction (D) orthogonal to the thickness direction (H). The offset length d of the end (30A) of the adhesive layer (30) from the film end surface (12) and the extended surface (12 ') of the film end surface (12) is 5 [mu] m or less.

Description

Adhesive layer with cover film

The present invention relates to an adhesive layer with a covering film.

The display panel, for example, has a laminated structure including components such as a pixel panel, a polarizing film, a touch panel, and a cover film. In the manufacturing process of such a display panel, in order to bond the components included in the laminated structure to each other, for example, a transparent adhesive is used.

On the other hand, for example, for use in smartphones and tablet terminals, display panels that can be bent repeatedly (foldable) are being developed. Specifically, a foldable display panel can be repeatedly deformed between a curved shape and a flat non-curved shape. In such a foldable display panel, each element in the laminated structure is manufactured in a manner that can be bent repeatedly, and a soft adhesive is used to join such elements. For example, a sheet adhesive (adhesive sheet) for a flexible device such as a foldable display panel is described in the following patent document 1. [Prior art document] [Patent document]

[Patent Document 1] Japanese Patent Publication No. 2018-111754

[The problem the invention is trying to solve]

Conventionally, adhesive sheets for flexible devices are manufactured, for example, as follows.

First, as shown in FIG6A , a laminated sheet 60 is prepared as a long raw material sheet. The laminated sheet 60 includes a peeling liner 61, an adhesive layer 62, and a peeling liner 63 in order in the thickness direction H. The peeling liner 61 is in contact with one surface of the adhesive layer 62 in a peelable manner. The peeling liner 63 is in contact with the other surface of the adhesive layer 62 in a peelable manner.

Next, as shown in FIG6B , the adhesive layer 62 in the laminated sheet 60 is punched to form an adhesive layer 62A as a single sheet of adhesive sheet (punching process step). Specifically, the adhesive layer 62 on the peeling pad 61 is formed into an adhesive layer 62A having a predetermined top view shape by inserting a processing knife (not shown) from the peeling pad 63 side to the peeling pad 61 (the cutting portion 65 of the processing knife is schematically indicated by a thick solid line). A peripheral portion 62a is generated around the adhesive layer 62A. In this step, the peeling liner 63 is also punched to form a peeling liner 63A having the same top view shape as the adhesive layer 62A, and a peripheral portion 63a is generated around the peeling liner 63A.

Next, as shown in FIG. 6C , the peripheral portions 62a and 63a ( FIG. 6B ) are removed from the peeling pad 61.

Thereafter, as shown in Fig. 6D, the strip of release liner 61 is cut into single-piece release liner 61A, thereby obtaining a single-piece adhesive layer 60' (release liner 61A/adhesive layer 62A/release liner 63A) with a covering film in the form of an adhesive sheet with release liner attached to both sides.

The adhesive sheet (adhesive layer) for a soft device is required to be highly soft so as to have sufficient tracking properties to the adherend when the device is bent and excellent stress relief properties. However, in the above-mentioned manufacturing method, the softer the adhesive layer 62 is, the easier it is for the adhesive layer 62 to adhere to the processing knife in the stamping process step (Figure 6B) and be pulled by the processing knife. Therefore, as shown in Figure 7, a protrusion 62E is easily formed in the adhesive layer 62A after stamping. The protrusion 62E is a portion of the end 62e of the adhesive layer 62A extending to the outside of the end 63e of the peeling pad 63A. Previously, the extension length d' of the protrusion 62E after the stamping process was longer than 6 μm.

When the adhesive layers 60' with covering films are stacked, the protrusion 62E may cause the ends of the adjacent adhesive layers 60' with covering films to adhere to each other (end adhesion). End adhesion may lead to a decrease in the operability of the adhesive layers 60' with covering films. In addition, the protrusion 62E may cause the paste contamination of the adhesive layers 60' with covering films. These abnormalities may also occur when a surface protective film with an adhesive layer is formed on the peeling pad 61A (the peeling pad 61A is attached to the side of the adhesive layer) instead of the adhesive layer 62A and the peeling pad 63A.

The present invention provides an adhesive layer with a covering film, which is suitable for inhibiting end adhesion and paste contamination. [Technical means for solving the problem]

The present invention [1] includes an adhesive layer with a covering film, which comprises a first covering film, an adhesive layer, and a second covering film in order in the thickness direction, wherein the first covering film has a first surface located on the side of the adhesive layer and has a film end surface forming an acute angle with the first surface, and the second covering film has an extended end portion, the extended end portion extends in a surface direction perpendicular to the thickness direction to the outside of the end portion of the adhesive layer, and the positional offset length of the end portion of the adhesive layer from the film end surface and the extended surface of the film end surface is less than 5 μm.

The present invention [2] comprises the adhesive layer with a covering film as described in the above [1], wherein the gel fraction of the adhesive layer is less than 80%.

The present invention [3] includes the adhesive layer with a covering film as described in [1] or [2] above, wherein the adhesive layer has a thickness of not less than 5 μm and not more than 50 μm.

The present invention [4] includes an adhesive layer with a covering film as described in any one of the above [1] to [3], wherein the angle of the sharp angle in the above first covering film is not less than 40° and not more than 85°.

The present invention [5] includes an adhesive layer with a covering film as described in [4] above, wherein the adhesive layer has an adhesive surface located on the side of the second covering film and has an adhesive layer end surface forming an acute angle with the adhesive surface, and the ratio of the acute angle of the adhesive layer to the acute angle of the first covering film is greater than 0.9 and less than 1.5.

The present invention [6] includes an adhesive layer with a covering film as described in any one of the above [1] to [5], wherein the difference between the maximum and minimum values of the edge width of the edge representing the edge of the above first covering film in a top view is less than 10 μm. [Effect of the invention]

In the adhesive layer with a cover film of the present invention, as described above, the positional deviation length (protrusion amount) of the end of the adhesive layer from the film end surface and the extension surface of the end surface is less than 5 μm, which is small. Such an adhesive layer with a cover film is suitable for suppressing the above-mentioned end adhesion and paste contamination.

As shown in FIG. 1 and FIG. 2 , an adhesive layer with a covering film X as one embodiment of the adhesive layer with a covering film of the present invention includes covering films 10, 20, and an adhesive layer 30. Specifically, the adhesive layer with a covering film X includes the covering film 10 (first covering film), the adhesive layer 30, and the covering film 20 (second covering film) in order in the thickness direction H. The adhesive layer with a covering film X extends in a plane direction D orthogonal to the thickness direction H.

The covering film 10 is, for example, a transparent surface protective film for a flexible device. The covering film 10 has a first surface 11 on the side of the adhesive layer 30 and a film end surface 12. The first surface 11 forms an acute angle with the film end surface 12. That is, the film end surface 12 is an inclined end surface inclined in a manner of forming an acute angle with the first surface 11. The adhesive layer 30 is bonded to the first surface 11. The adhesive layer 30 has an adhesive surface 31 located on the side of the covering film 20. Such a covering film 10 and the adhesive layer 30 form a surface protective film Y with an adhesive layer attached.

The position offset length d (protrusion amount) of the end 30A of the adhesive layer 30 from the film end surface 12 of the covering film 10 and the extension surface 12' of the film end surface 12 (indicated by an imaginary line in Figures 2 to 4) is less than 5 μm. The position offset length d is the maximum length in the orthogonal direction relative to the film end surface 12 and the extension surface 12'. Figure 2 exemplarily shows a case where the position offset length d is 0 μm. Figure 3 exemplarily shows a case where the position offset length d is a positive value. The positive value of the position offset length d means that the end 30A of the adhesive layer 30 protrudes outward from the film end surface 12 and the extension surface 12'. Figure 4 exemplarily shows a case where the position offset length d is a negative value. The position deviation length d being a negative value means that the end portion 30A of the adhesive layer 30 is recessed or retreated to a position further inward than the extension surface 12'. The method for measuring the position deviation length d is specifically described in the following examples.

The covering film 20 is a peelable liner. The covering film 20 has a peelable surface 21. The covering film 20 is in contact with the adhesive layer 30 via the peelable surface 21 side in a peelable manner. In addition, the covering film 20 has an extended end 20A. The extended end 20A extends in the surface direction D to the outside of the end 30A of the adhesive layer 30. This type of covering film 20 is peeled off from the adhesive layer 30 when using a surface protection film Y with an adhesive layer.

Such adhesive layer X with cover film is used as a supply material of surface protection film Y with adhesive layer included in the laminated structure of the device, for example, during the manufacturing process of the flexible device. As a flexible device, for example, a flexible display panel can be cited. The flexible display panel has a laminated structure including components such as a pixel panel, a polarizing film, a touch panel, and a cover film (surface protection film).

As described above, in the adhesive layer X with a covering film, the positional deviation length d (protrusion amount) of the end 30A of the adhesive layer 30 from the film end surface 12 and the extension surface 12' of the film end surface 12 is less than 5 μm, which is relatively small. This type of adhesive layer X with a covering film is suitable for suppressing the above-mentioned end adhesion and paste contamination. Specifically, as shown in the following embodiments and comparative examples.

From the viewpoint of suppressing end adhesion and suppressing paste contamination, the positional offset length d is preferably 4 μm or less, more preferably 3 μm or less, further preferably 2 μm or less, further preferably 1 μm or less, and particularly preferably 0.5 μm or less. From the viewpoint of ensuring the protective function of the adhesive layer 30 for the end of the cover film 10, the positional offset length d is preferably -10 μm or more, more preferably -5 μm or more, further preferably -3 μm or more, and particularly preferably -0.5 μm or more. From the viewpoint of simultaneously having the above-mentioned suppression of end adhesion and paste contamination and the above-mentioned ensuring protection function, the positional offset length d is optimally 0 μm.

From the viewpoint of ensuring the edge width W described later, the angle α of the above-mentioned sharp angle formed by the first surface 11 of the covering film 10 and the film end surface 12 is preferably 40° or more, more preferably 45° or more, and further preferably 48° or more. From the viewpoint of preventing production line contamination when the adhesive layer X with the covering film is transported through the device production line, the angle α is preferably 85° or less, more preferably 80° or less, and further preferably 75° or less. As a method for adjusting the angle α, for example, the adjustment of the laser irradiation conditions in the laser processing described later can be cited. As laser irradiation conditions, for example, the wavelength of the laser light, the pulse width of the laser light, the frequency of the pulse, the laser output, and the beam spot diameter of the laser light can be cited.

From the viewpoint of ensuring adhesion to the surface protection film Y with the adhesive layer, the thickness of the adhesive layer 30 is preferably 5 μm or more, more preferably 10 μm or more, and further preferably 12 μm or more. From the viewpoint of thinning the surface protection film Y with the adhesive layer, the thickness of the adhesive layer 30 is preferably 50 μm or less, more preferably 40 μm or less, further preferably 30 μm or less, and particularly preferably 25 μm or less.

From the viewpoint of ensuring the softness of the adhesive layer 30, the gel fraction of the adhesive layer 30 is preferably 80% or less, more preferably 75% or less, and further preferably 70% or less. From the viewpoint of ensuring the cohesive force of the adhesive layer 30, the gel fraction of the adhesive layer 30 is preferably 40% or more, more preferably 45% or more, and further preferably 50% or more. As a method for adjusting the gel fraction, for example, the selection of the type of base polymer in the adhesive layer 30, the adjustment of the molecular weight, and the adjustment of the formulation amount can be cited. The method for measuring the gel fraction is described in the following examples.

From the viewpoint of ensuring the softness of the adhesive layer 30, the shear storage modulus of the adhesive layer 30 at 25°C is preferably 200 kPa or less, more preferably 100 kPa or less, and further preferably 70 kPa or less. From the viewpoint of ensuring the adhesive force of the adhesive layer 30, the shear storage modulus of the adhesive layer 30 at 25°C is preferably 10 kPa or more, more preferably 15 kPa or more, further preferably 20 kPa or more, and particularly preferably 25 kPa or more. As a method for adjusting the shear storage modulus, for example, selection of the type of base polymer in the adhesive layer 30, adjustment of the molecular weight, and adjustment of the formulation amount can be cited. The method for determining the shear storage modulus is described in the examples below.

The adhesive layer 30 preferably has an end face 32 that forms an acute angle with the adhesive surface 31. From the viewpoint of ensuring the edge width W described later, the angle β of the acute angle is preferably 40° or more, more preferably 45° or more, and further preferably 48° or more. From the viewpoint of preventing contamination of the production line when the adhesive layer X with a covering film is transported through the device production line, the angle β is preferably 85° or less, more preferably 80° or less, and further preferably 75° or less. As a method for adjusting the angle β, for example, the adjustment of the laser irradiation conditions in the laser processing described later can be cited.

The ratio (β/α) of the angle β in the adhesive layer 30 to the angle α in the cover film 10 is preferably 0.9 or more, more preferably 1.00 or more, further preferably 1.01 or more, further preferably 1.05 or more, further preferably 1.10 or more, particularly preferably 1.15 or more, and particularly preferably 1.20 or more. The ratio (β/α) is preferably 1.5 or less, more preferably 1.4 or less, and further preferably 1.3 or less. Such structures are better for suppressing erroneous detection caused by a detection camera when the area with edge width W described later is used as an alignment mark for edge detection, and are also better for suppressing measurement errors when the area with edge width W is used to measure the size of the adhesive layer X with a covering film.

Examples of materials for the cover film 10 (surface protection film) include polyimide (PI), polyester, polyolefin, and polycarbonate. Examples of polyester include polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate. Examples of polyolefin include polyethylene, polypropylene, and cycloolefin polymer (COP).

From the perspective of ensuring the protective function as a surface protective film, the thickness of the cover film 10 is preferably 10 μm or more, more preferably 15 μm or more, and further preferably 20 μm or more. From the perspective of thinning the surface protective film Y with an adhesive layer, the thickness of the cover film 10 is preferably 100 μm or less, more preferably 70 μm or less, and further preferably 50 μm or less.

In the present embodiment, the covering film 10 has a protrusion 13 on the side opposite to the adhesive layer 30. The protrusion 13 is on the surface (second surface) on the side opposite to the first surface 11 of the covering film 10, and protrudes toward the side opposite to the adhesive layer 30. The protrusion height of the protrusion 13 is, for example, greater than 0.1 μm, and, for example, less than 20 μm. Furthermore, the protrusion 13 is arranged along the film end surface 12. In the first outer shape processing step (FIG. 5B) described later by laser processing, such a protrusion 13 is formed along the film end surface 12 of the covering film 10 by melting the covering film 101 by laser irradiation.

As the material of the cover film 20 (peeling pad), for example, polyester, polyolefin, polycarbonate, and polyimide can be cited. As the material of the cover film 20, specifically, the materials related to the cover film 10 mentioned above can be cited.

The peeling surface 21 of the cover film 20 is preferably subjected to a peeling treatment. Examples of the peeling treatment include silicone peeling treatment and fluorine peeling treatment.

From the viewpoint of ensuring the protective function of the cover film 20 for the adhesive layer 30, the thickness of the cover film 20 is preferably 5 μm or more, more preferably 10 μm or more, and further preferably 15 μm or more. From the viewpoint of preventing peeling errors when the cover film 20 is peeled off from the adhesive layer 30, the thickness of the cover film 20 is preferably 200 μm or less, more preferably 150 μm or less, and further preferably 100 μm or less.

From the viewpoint of ensuring the protective function of the covering film 20 for the adhesive layer 30, the extension length of the extended end portion 20A relative to the covering film 10 in the plane direction D (the extension length from the film end surface 12) is preferably 0.1 mm or more, more preferably 0.5 mm or more, further preferably 1 mm or more, and particularly preferably 1.5 mm or more. From the viewpoint of efficiently manufacturing the adhesive layer X with the covering film, the extension length is preferably 100 mm or less, more preferably 50 mm or less, and further preferably 30 mm or less.

As shown in FIGS. 2 to 4 , in the adhesive layer X with a covering film, the distance between the inner end of the protrusion 13 of the covering film 10 in the plane direction D and the outer end of the covering film 20 in the plane direction D is set as the edge length L. The edge length L includes the above-mentioned extension length of the extension end 20A. From the viewpoint of ensuring the protective function of the covering film 20 for the adhesive layer 30, such edge length L is preferably 0.1 mm or more, more preferably 0.5 mm or more, further preferably 1 mm or more, and particularly preferably 1.5 mm or more. From the viewpoint of efficiently manufacturing the adhesive layer X with a cover film, the edge length L is preferably 100 mm or less, more preferably 50 mm or less, and further preferably 30 mm or less.

In the present embodiment, the covering film 20 has a half-cut groove 22 along the end surface 32 of the adhesive layer 30 on the peeling surface 21 side. The half-cut groove 22 has a depth in the thickness direction H. As shown in FIG. 2 , the half-cut groove 22 has an inner wall surface 22a (first inner wall surface), an inner wall surface 22b (second inner wall surface), and a round bottom 22c. The inner wall surface 22a is arranged on the inner side (adhesive layer 30 side) in the surface direction D of the half-cut groove 22. The inner wall surface 22a and the end surface 32 of the adhesive layer 30 are in the same plane. The inner wall surface 22b is arranged on the outer side in the surface direction D of the half-cut groove 22. The inner wall surface 22b is separated from the inner wall surface 22a in the surface direction D and is opposite to the inner wall surface 22a in the surface direction D. The round bottom 22c is disposed between the inner wall surfaces 22a and 22b in the plane direction D. In a plan view, in a cross section perpendicular to the extending direction of the half-cut groove 22 extending along the end surface 32 ( FIG. 2 ), the round bottom 22c has an expanded curved shape, for example, with a curvature radius of 1 μm or more.

In a top view, the edge width W of the edge of the edge of the covering film 10 is preferably greater than 10 μm, more preferably greater than 15 μm, further preferably greater than 20 μm, and particularly preferably greater than 25 μm (the edge width W in the present embodiment is the distance between the inner end of the protrusion 13 of the covering film 10 in the surface direction D and the outer end of the half-cut groove 22 of the covering film 20 in the surface direction D). The configuration related to the edge width W is preferably used for appropriately detecting the mark by a detection camera when the edge width W region (in this embodiment, the region between the inner end of the protrusion 13 and the outer end of the half-cut groove 22) is used as an alignment mark for edge detection, and is also preferably used for accurately measuring the size of the adhesive layer X with a covering film by using the edge width W region (the edge width region is a portion that can be confirmed as a dark-colored region by the detection camera). The edge width W is preferably 300 μm or less, more preferably 250 μm or less, further preferably 200 μm or less, and particularly preferably 150 μm or less. This type of structure is preferably used to suppress erroneous detection caused by a detection camera when the area of the edge width W is used as an alignment mark for edge detection, and is preferably used to suppress measurement errors when the adhesive layer X with the covering film is measured using the area of the edge width W. In the case where the covering film 10 does not have the protruding strip 13, the edge width W may also be the distance between the inner end of the film end surface 12 of the covering film 10 in the surface direction D and the outer end of the half-cut groove 22 of the covering film 20 in the surface direction D. When the covering film 20 does not have the half-cut groove 22, the edge width W may also be the distance between the inner end of the protrusion 13 of the covering film 10 in the plane direction D and the outer end of the end surface 32 of the adhesive layer 30 in the plane direction D. When the covering film 10 does not have the protrusion 13 and the covering film 20 does not have the half-cut groove 22, the edge width W may also be the distance between the inner end of the film end surface 12 of the covering film 10 in the plane direction D and the outer end of the end surface 32 of the adhesive layer 30 in the plane direction D.

The difference between the maximum and minimum values of the edge width W is preferably 10 μm or less, more preferably 7 μm or less, further preferably 5 μm or less, and particularly preferably 3 μm or less. This type of edge structure is preferred for appropriately detecting the mark with a detection camera when the area of the edge width W is used as an alignment mark for edge detection, and is also preferred for accurately measuring the size of the adhesive layer X attached to the covering film using the area of the edge width W. The difference between the maximum and minimum values of the edge width W refers to the difference between the maximum and minimum values of the edge width W within a range of 1 mm length (cut length) in the circumferential direction of the peripheral edge of the covering film 10 when viewed from above. The method for determining the difference between the maximum value and the minimum value of the edge width W is specifically described in the examples below.

The adhesive layer 30 is formed by an adhesive composition. The adhesive composition includes a base polymer. The base polymer is an adhesive component that exhibits adhesiveness. Examples of the base polymer include acrylic polymers, polyurethane polymers, polyamide polymers, and polyvinyl ether polymers. The base polymer can be used alone or in combination of two or more. From the perspective of ensuring good transparency and adhesiveness of the adhesive layer 30, it is preferred to use an acrylic polymer as the base polymer.

The acrylic polymer is a copolymer containing a monomer component of (meth)acrylate at a ratio of 50 mass % or more. "(Meth)acrylic acid" means acrylic acid and/or methacrylic acid. As the (meth)acrylate, it is preferred to use an alkyl (meth)acrylate, and it is more preferred to use an alkyl (meth)acrylate having an alkyl group with 1 to 20 carbon atoms.

Examples of the alkyl (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, pentyl (meth)acrylate, n-hexyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate (i.e., lauryl (meth)acrylate), isotridecyl (meth)acrylate, and tetradecyl (meth)acrylate. The alkyl (meth)acrylate is preferably at least one selected from the group consisting of 2-ethylhexyl acrylate (2EHA), lauryl acrylate (LA), and n-butyl acrylate. From the viewpoint of appropriately expressing basic properties such as adhesion of the adhesive layer 30, the ratio of the (meth)acrylate in the monomer component is preferably 50 mass % or more, more preferably 70 mass % or more, further preferably 90 mass % or more, and, for example, 99 mass % or less.

The monomer component may also include a copolymerizable monomer that can copolymerize with the (meth)acrylic acid alkyl ester. As the copolymerizable monomer, for example, a monomer having a polar group can be cited. As the monomer containing a polar group, for example, a monomer containing a hydroxyl group, a monomer containing a carboxyl group, and a monomer having a ring containing a nitrogen atom can be cited. The monomer containing a polar group contributes to the modification of the acrylic polymer, for example, introducing a crosslinking point into the acrylic polymer, ensuring the cohesive force of the acrylic polymer, etc.

Examples of the hydroxyl-containing monomer include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. As the hydroxyl-containing monomer, it is preferred to use at least one selected from the group consisting of 2-hydroxyethyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate. From the viewpoint of introducing a crosslinking structure into the acrylic polymer and ensuring the cohesive force in the adhesive layer 30, the ratio of the hydroxyl-containing monomer in the monomer component is preferably 1% by mass or more, more preferably 2% by mass or more, and further preferably 3% by mass or more. From the viewpoint of adjusting the polarity of the acrylic polymer (related to the compatibility of the various additive components in the adhesive layer 30 with the acrylic polymer), the ratio is preferably 20% by mass or less, and more preferably 10% by mass or less.

Examples of monomers having a ring containing a nitrogen atom include N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperidone, N-vinylpyrrole, N-vinylimidazole, and N-(methyl)acryloyl-2-pyrrolidone. As a monomer having a ring containing a nitrogen atom, N-vinyl-2-pyrrolidone is preferably used. From the viewpoint of ensuring the cohesive force in the adhesive layer 30 and the close contact force of the adhesive layer 30 with the adherend, the ratio of the monomer having a ring containing a nitrogen atom in the monomer component is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and further preferably 1% by mass or more. From the viewpoint of adjusting the glass transition temperature of the acrylic polymer and adjusting the polarity of the acrylic polymer (related to the compatibility of various additive components in the adhesive layer 30 with the acrylic polymer), the ratio is preferably 30% by mass or less, and more preferably 20% by mass or less.

The base polymer preferably has a crosslinking structure. As methods for introducing a crosslinking structure into the base polymer, the following methods can be cited: a method of preparing a base polymer having a functional group that can react with the crosslinking agent and a crosslinking agent in an adhesive composition, and reacting the base polymer and the crosslinking agent in the adhesive layer (first method); and a method of making the monomer component forming the base polymer contain a multifunctional monomer as a crosslinking agent, and polymerizing the monomer component to form a base polymer having a branched structure (crosslinking structure) introduced into the polymer chain (second method). These methods can also be used in combination.

As the crosslinking agent used in the first method, for example, there can be cited compounds that react with functional groups (hydroxyl groups and carboxyl groups, etc.) contained in the base polymer. As such crosslinking agents, for example, there can be cited isocyanate crosslinking agents, peroxide crosslinking agents, and epoxy crosslinking agents. The crosslinking agents can be used alone or in combination of two or more.

In the second method described above, the monomer components (including the multifunctional monomers and other monomers used to introduce the crosslinking structure) can be polymerized at once or in multiple stages. In the multistage polymerization method, first, the monofunctional monomer used to form the base polymer is polymerized (prepolymerization) to prepare a prepolymer composition containing a partial polymer (a mixture of a polymer with a low degree of polymerization and unreacted monomers). Subsequently, after adding a multifunctional monomer as a crosslinking agent to the prepolymer composition, the partial polymer is polymerized with the multifunctional monomer (formal polymerization). As a multifunctional monomer, for example, a multifunctional (meth) acrylate containing two or more ethylenically unsaturated double bonds in one molecule can be cited. As a multifunctional monomer, a multifunctional acrylate is preferred from the viewpoint that a crosslinking structure can be introduced by active energy line polymerization (photopolymerization). Examples of the multifunctional (meth)acrylate include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, trihydroxymethylpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, and dipentaerythritol hexa(meth)acrylate. As the multifunctional (meth)acrylate, dipentaerythritol hexaacrylate (DPHA) is preferably used.

The acrylic polymer can be formed by polymerizing the above-mentioned monomer components. Examples of the polymerization method include solution polymerization, solvent-free photopolymerization (e.g., UV (Ultraviolet) polymerization), bulk polymerization, and emulsion polymerization. Examples of solvents used in solution polymerization include ethyl acetate and toluene. Examples of polymerization initiators include thermal polymerization initiators and photopolymerization initiators.

From the viewpoint of ensuring the cohesive force in the adhesive layer 30, the weight average molecular weight of the base polymer is preferably 100,000 or more, more preferably 300,000 or more, and further preferably 500,000 or more. The weight average molecular weight is preferably 5 million or less, more preferably 3 million or less, and further preferably 2 million or less. The weight average molecular weight of the base polymer is measured by gel permeation chromatography (GPC) and calculated based on polystyrene conversion.

From the viewpoint of ensuring the softness of the adhesive layer 30, the glass transition temperature (Tg) of the base polymer is preferably below 0°C, more preferably below -10°C, and further preferably below -20°C. The glass transition temperature is, for example, above -80°C.

Regarding the glass transition temperature (Tg) of the base polymer, the glass transition temperature (theoretical value) obtained based on the following Fox formula can be used. The Fox formula is a relationship between the glass transition temperature Tg of the polymer and the glass transition temperature Tgi of the homopolymer of the monomer constituting the polymer. In the following Fox formula, Tg represents the glass transition temperature of the polymer (°C), Wi represents the weight fraction of the monomer i constituting the polymer, and Tgi represents the glass transition temperature of the homopolymer formed by the monomer i (°C). The glass transition temperature of the homopolymer can be a literature value. For example, "Polymer Handbook" (4th edition, John Wiley & Sons, Inc., 1999) and "New Polymer Library 7: Introduction to Synthetic Resins for Coatings" (edited by Kyozo Kitaoka, Polymer Publishing Company, 1995) list the glass transition temperatures of various homopolymers. On the other hand, the glass transition temperature of a homopolymer of a monomer can also be obtained by the method specifically described in Japanese Patent Publication No. 2007-51271.

Fox formula 1/(273＋Tg)＝Σ[Wi/(273＋Tgi)]

The adhesive composition may contain other components as needed. Examples of other components include solvents, silane coupling agents, ultraviolet absorbers, adhesion promoters, softeners, and antioxidants. Examples of solvents include polymerization solvents used as needed when polymerizing acrylic polymers and solvents added to the polymerization reaction solution after polymerization. Examples of the solvent include ethyl acetate and toluene.

The haze of the adhesive layer 30 is preferably 3% or less, more preferably 2% or less, and further preferably 1% or less. The haze of the adhesive layer 30 can be measured using a mist meter in accordance with JIS K7136 (2000). Examples of the mist meter include "NDH2000" manufactured by Nippon Denshoku Industries and "HM-150" manufactured by Murakami Color Technology Research Institute.

The adhesive layer X with a cover film can be manufactured, for example, as follows.

First, as shown in FIG5A, a long laminated sheet Z is prepared (laminated sheet preparation step). The laminated sheet Z has a long covering film 102, an adhesive layer 103, and a long covering film 101 in order in the thickness direction H. The laminated sheet Z can be prepared, for example, as follows: the adhesive composition is applied on the covering film 102 to form a coating film, the covering film 101 is attached to the coating film, the coating film is dried, and light irradiation is performed as needed. Examples of the coating method of the adhesive composition include roller coating, contact roller coating, gravure coating, reverse coating, roller brushing, spray coating, dip roller coating, rod coating, scraper coating, air knife coating, curtain coating, die lip coating, and die nozzle coating. The drying temperature of the coating film is, for example, 50° C. to 200° C. The drying time is, for example, 5 seconds to 20 minutes.

Next, as shown in FIG. 5B , the adhesive layer 103 on the cover film 102 is laser processed to form an adhesive layer 30 of a predetermined top view shape (first outer shape processing step). Specifically, the laminated sheet Z is irradiated with laser light from the side of the cover film 101 in the thickness direction H along the pre-cut line of the laminated sheet Z, thereby cutting the adhesive layer 103 on the cover film 102 and the cover film 101. Thus, an adhesive layer 30 having a predetermined shape in a plan view is formed in the adhesive layer 103, and a peripheral portion 103a (first peripheral portion) is generated around the adhesive layer 30. A covering film 10 is formed in the covering film 101, and a peripheral portion 101a (second peripheral portion) is formed around the covering film 10.

Examples of laser light for laser processing include gas lasers, solid lasers, and semiconductor lasers. Examples of gas lasers include excimer lasers and _CO2 lasers (9.4 μm) (the numbers in parentheses represent the wavelength of the laser light. This applies to all lasers hereinafter). Examples of excimer lasers include _F2 excimer lasers (157 nm), ArF excimer lasers (193 nm), KrF excimer lasers (248 nm), and XeCl excimer lasers (308 nm). Examples of solid-state lasers include Nd:YAG (Neodymium-doped Yttrium Aluminum Garnet) lasers (1064 nm), second harmonics of Nd:YAG lasers (532 nm), third harmonics of Nd:YAG lasers (355 nm), and fourth harmonics of Nd:YAG lasers (266 nm). Examples of semiconductor lasers include semiconductor lasers with a wavelength of 405 nm. In laser processing, the pulse width of the irradiated laser light is, for example, 0.5 to 50 μs, the pulse frequency is, for example, 1 to 200 kHz, the laser output is, for example, 2 to 250 W, and the beam spot diameter of the laser light is, for example, 50 to 500 μm.

As described above, the angle α formed by the first surface 11 of the cover film 10 and the film end surface 12 formed in this step is preferably 40° or more, more preferably 45° or more, and further preferably 48° or more; and preferably 85° or less, more preferably 80° or less, and further preferably 75° or less. As a method for adjusting the angle α, for example, the adjustment of the laser irradiation conditions in laser processing can be cited. As laser irradiation conditions, for example, the pulse width of the laser light, the pulse frequency, the laser output, and the beam spot diameter of the laser light can be cited.

Next, as shown in FIG. 5C , the peripheral portions 101a and 103a ( FIG. 5B ) are removed from the cover film 102 (removal step).

Next, as shown in Fig. 5D, the strip of cover film 102 is cut into individual sheets of cover film 20 (second outer shape processing step). Examples of the cutting method include cutting by irradiation with laser light and cutting by punching.

In this way, an adhesive layer X with a covering film can be produced.

The adhesive layer X with a covering film may also be an adhesive sheet with peel-off pads on both sides. Specifically, the adhesive layer X with a covering film may also be an adhesive sheet in which the adhesive layer 30 is a long strip, and the covering film 10 is connected to the peel-off pad in a peelable manner. In this case, the first surface 11 of the covering film 10 is preferably a peel-off surface subjected to a peeling treatment. In this type of adhesive layer X with a covering film, the covering films 10 and 20 are peeled off from the adhesive layer 30 when used as the adhesive layer 30 of the adhesive sheet. [Example]

The following examples are shown to specifically explain the present invention. However, the present invention is not limited to the examples. In addition, the specific numerical values of the blending amounts (contents), physical property values, parameters, etc. described below can be replaced by the upper limit (defined as a value "below" or "less than") or lower limit (defined as a value "above" or "exceeding") of the corresponding blending amounts (contents), physical property values, parameters, etc. described in the above "Implementation Methods".

[Example 1] ＜Preparation of adhesive composition＞ First, a mixture containing 50 parts by mass of 2-ethylhexyl acrylate (2EHA), 40 parts by mass of lauryl acrylate (LA), 2 parts by mass of n-butyl acrylate (BA), 6 parts by mass of 4-hydroxybutyl acrylate (4HBA), 2 parts by mass of N-vinyl-2-pyrrolidone (NVP), and 0.015 parts by mass of a photopolymerization initiator (product name "Omnirad 184", manufactured by IGM Resins) was irradiated with ultraviolet light (polymerization reaction) to obtain a prepolymer composition (polymerization rate of about 10%) (the prepolymer composition contains monomer components that have not undergone polymerization reaction). Next, 100 parts by mass of the prepolymer composition, 0.08 parts by mass of dipentaerythritol hexaacrylate (DPHA) as a multifunctional acrylate monomer, and 0.3 parts by mass of a silane coupling agent (product name "KBM-403", 3-glycidyloxypropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed to obtain an adhesive composition C1.

<Preparation of peeling pad> First, 90 parts by weight of silicone peeling agent (product name "KE-3703", a 28.5% by weight toluene solution of an addition-type silicone peeling agent containing a polyorganosiloxane having a hexene group in the molecule and a polyorganosiloxane crosslinking agent having a hydrosilyl group in the molecule, manufactured by Shin-Etsu Chemical Co., Ltd.) and silicone peeling agent. 0.9 parts by mass of a control agent (product name "KS-3800", manufactured by Shin-Etsu Chemical Co., Ltd.), 0.3 parts by mass of a platinum catalyst for silicone curing (product name "CAT-PL-50T", manufactured by Shin-Etsu Chemical Co., Ltd.), and a solvent are mixed to prepare a stripping agent solution having a silicone solid content concentration of 0.7% by mass. The solvent is a mixed solvent of toluene and hexane in a volume ratio of 1:1. Next, a stripping treatment is applied to a biaxially stretched polyester film (product name "Lumirror XD500P", thickness 75 μm, manufactured by Toray Advanced Materials Korea). Specifically, first, the above-mentioned stripping agent solution is applied to one side of the polyester film to form a coating film. The coating was performed using a wire bar coater #9. The coating on the film was then heated at 130°C for 1 minute in a hot air dryer to dry it. Thus, a silicone release layer (release treatment) with a thickness of 0.1 μm was formed on the polyester film. In this way, a release pad having a release treatment surface on one side was produced.

<Production of laminated sheets> First, the adhesive composition C1 is applied to the peeling treated surface of the above-mentioned peeling pad (second covering film) to form a coating. Then, the plasma-treated surface of the surface protection film (first covering film) that has been plasma-treated on one side is attached to the coating on the peeling pad. The surface protection film is a transparent polyimide (PI) film with a thickness of 49 μm. During the plasma treatment, a plasma irradiation device (product name "AP-TO5", manufactured by Sekisui Industries) is used, and the voltage is set to 160 V, the frequency is set to 10 kHz, and the treatment speed is set to 5000 mm/min. Then, the coating film was irradiated with ultraviolet rays from the surface protective film side to cure the coating film by ultraviolet rays, thereby forming an adhesive layer (adhesive A1) with a thickness of 25 μm. Thus, a laminated sheet (peel-off liner/adhesive layer/surface protective film) as a raw sheet of an adhesive layer with a covering film was obtained. During the ultraviolet irradiation, a black light was used as the irradiation light source, and the irradiation intensity was set to 5 mW/cm ² (the same applies to the ultraviolet irradiation described later).

<First contour processing> Next, the adhesive layer of the laminated sheet is contour processed (first contour processing step). Specifically, the laminated sheet is irradiated with _CO2 laser light (wavelength 9.4 μm) from the surface protection film side in the thickness direction along the first pre-cut line of the laminated sheet, thereby cutting the adhesive layer and the surface protection film on the peeling pad in the thickness direction (laser processing). During the laser irradiation, the first laser processing device (product name "LC500", manufactured by Takei Electric Industry) was used, and the pulse width of the irradiated laser light was set to 3.3 μs, the laser output was set to 23 W, and the pulse frequency was set to 15 kHz. In this step, an adhesive layer having a predetermined top view shape and a first peripheral portion surrounding the adhesive layer are formed in the adhesive layer, and a second peripheral portion is formed on the first peripheral portion in the surface protection film.

<Removal of peripheral portion, second contour processing> After the first contour processing step, the first peripheral portion and the second peripheral portion are removed from the peel-off pad. Thereafter, the peel-off pad is contour processed (second contour processing step). Specifically, the peel-off pad is irradiated with _CO2 laser in the thickness direction along the second pre-cut line of the peel-off pad, thereby cutting the peel-off pad into a predetermined top view shape. The second pre-cut line is 3 mm further outward in the surface direction than the first pre-cut line mentioned above. In the laser irradiation of this step, the first laser processing device (product name "LC500", manufactured by Takei Electric Industry) was used, and the pulse width of the irradiated laser light was set to 3.3 μs, the laser output was set to 40 W, and the pulse frequency was set to 15 kHz.

Thus, the adhesive layer with covering film (surface protection film/adhesive layer/peel-off liner) of Example 1 was prepared. The adhesive layer with covering film of Example 1 comprises a surface protection film with an adhesive layer (thickness 25 μm) and a peel-off liner covering the adhesive layer side of the film.

[Example 2] First, a mixture containing 45 parts by mass of 2-ethylhexyl acrylate (2EHA), 42 parts by mass of lauryl acrylate (LA), 2 parts by mass of n-butyl acrylate (BA), 4 parts by mass of 4-hydroxybutyl acrylate (4HBA), 7 parts by mass of N-vinyl-2-pyrrolidone (NVP), and 0.015 parts by mass of a photopolymerization initiator (Omnirad 184) was irradiated with ultraviolet light (polymerization reaction) to obtain a prepolymer composition (polymerization rate of about 10%). Next, 100 parts by mass of the prepolymer composition, 0.08 parts by mass of dipentaerythritol hexaacrylate (DPHA) as a multifunctional acrylate monomer, and 0.3 parts by mass of a silane coupling agent (product name "KBM-403", 3-glycidyloxypropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed to obtain an adhesive composition C2. The adhesive composition C2 was used to replace the adhesive composition C1 to form an adhesive layer (adhesive A2) with a thickness of 15 μm. Otherwise, the adhesive layer with a covering film of Example 1 was operated in the same manner to obtain the adhesive layer with a covering film of Example 2 (surface protection film/adhesive layer/peeling pad).

[Example 3] In the lamination sheet manufacturing step, the thickness of the formed adhesive layer is set to 15 μm. In the first shape processing step, the pulse frequency of the irradiated laser light is set to 30 kHz. In addition, the adhesive layer with a covering film of Example 3 is prepared in the same manner as the adhesive layer with a covering film of Example 1.

[Example 4] In the first outer shape processing step, the second laser processing device (product name "LC750", manufactured by Takei Electric Industry) is used instead of the first laser processing device, and the pulse width of the irradiated laser light is set to 0.83 μs, the pulse frequency is set to 30 kHz, and the laser output is set to 23 W. In addition, the adhesive layer with a covering film of Example 4 is prepared in the same manner as the adhesive layer with a covering film of Example 1.

[Example 5] In the first shape processing step, the pulse frequency of the irradiated laser light is set to 30 kHz. In addition, the adhesive layer with a covering film of Example 5 is prepared in the same manner as the adhesive layer with a covering film of Example 1.

[Example 6] In the first shape processing step, the pulse frequency of the irradiated laser light is set to 5 kHz. In addition, the adhesive layer with a covering film of Example 6 is prepared in the same manner as the adhesive layer with a covering film of Example 1.

[Comparative Example 1] In the lamination sheet manufacturing step, the thickness of the formed adhesive layer is 15 μm. In the first outer shape processing step, stamping is performed instead of laser processing. Specifically, the adhesive layer on the peeling pad is inserted from the surface protection film side to the peeling pad in the thickness direction to form an adhesive layer of a predetermined top view shape. The first stamping knife has a blade tip with a blade angle of 80 degrees. In addition, the adhesive layer with a covering film of Comparative Example 1 is prepared in the same manner as the adhesive layer with a covering film of Example 1.

[Comparative Example 2] In the first outer shape processing step, punching is performed instead of laser processing. Specifically, for the adhesive layer on the peeling pad, the second punching tool is inserted from the surface protective film side to the peeling pad in the thickness direction, thereby forming an adhesive layer of a predetermined top view shape. The second punching tool has a blade tip with a blade angle of 30 degrees. In addition, the adhesive layer with a covering film of Comparative Example 2 is prepared in the same manner as the adhesive layer with a covering film of Example 2.

[Comparative Example 3] In the lamination sheet manufacturing step, the thickness of the formed adhesive layer is 15 μm. In the first outer shape processing step, punching processing is performed instead of laser processing. Specifically, for the adhesive layer on the peeling pad, the second punching processing knife (with a blade tip of 30 degrees) is inserted from the surface protection film side to the peeling pad in the thickness direction to form an adhesive layer of a predetermined top view shape. In addition, the adhesive layer with a covering film of Comparative Example 3 is prepared in the same manner as the adhesive layer with a covering film of Example 1.

<Gel fraction> The gel fraction of each adhesive layer in Examples 1 to 6 and Comparative Examples 1 to 3 was measured. Specifically, it is as follows.

First, collect about 0.1 g (mass: W ₁ mg) of adhesive sample from the adhesive layer. Then, wrap the adhesive sample into a drawstring bag using a tetrafluoroethylene resin porous membrane (mass: W ₂ mg) with an average pore size of 0.2 μm, and tie the opening with a kite line (mass: W ₃ mg) to obtain a package. The tetrafluoroethylene resin porous membrane is a porous membrane manufactured by Nitto Denko Co., Ltd. (product name "NITOFLON NTF1122"). Then, put the package containing the adhesive sample into a 50 mL container, and fill the container with ethyl acetate (one container for each package). After leaving it at 23°C for 7 days, take out the package from the container and dry it at 130°C for 2 hours. The mass of the package was then measured (W ₄ mg). The gel fraction of the adhesive layer was calculated by substituting the values of W ₁ to W ₄ into the following formula. The values are shown in Tables 1 and 2.

Gel fraction (%) = [(W ₄ －W ₂ －W ₃ )/W ₁ ] × 100

<Shear storage modulus> The dynamic viscoelasticity of each adhesive layer of Examples 1 to 6 and Comparative Examples 1 to 3 was measured.

First, the required number of samples for each adhesive layer is prepared. Specifically, first, a plurality of adhesive layer sheets cut from the adhesive layer are laminated to prepare a sample sheet with a thickness of about 1.5 mm. Then, the sheet is punched to obtain cylindrical particles (diameter 7.9 mm) as the sample for measurement.

Then, a dynamic viscoelasticity measurement is performed on the sample for measurement using a dynamic viscoelasticity measuring device (product name: "Advanced Rheometric Expansion System (ARES)", manufactured by Rheometric Scientific). Specifically, the sample for measurement is fixed to the parallel plate fixture of the device with a diameter of 7.9 mm, and then the measurement is performed. In this measurement, the measurement mode is set to the shear mode, the measurement temperature range is set to -40°C to 100°C, the heating rate is set to 5°C/min, and the frequency is set to 1 Hz. Based on the measurement results, the shear storage modulus at 25°C and the maximum shear storage modulus within the measurement temperature range are read. The values are shown in Tables 1 and 2.

<Shape analysis> The shape analysis of each adhesive layer in Examples 1 to 6 and Comparative Examples 1 to 3 was performed using a shape analysis laser microscope (product name "VK-X1000", manufactured by KEYENCE). Specifically, the microscope was used to measure the maximum and minimum values of the positional deviation length d of the end of the adhesive layer (Figures 2 to 4), the angle α of the end of the surface protective film (first covering film) (Figures 2 to 4), the angle β of the end of the adhesive layer (Figures 2 and 4), and the edge width W of the surface protective film (Figures 2 to 4). The results are shown in Tables 1 and 2. The ratio of angle β to angle α (β/α) is also shown in Tables 1 and 2. The positional offset length d is the length in the direction orthogonal to the film end surface (film end surface 12 in Figures 2 to 4) and the extension surface of the film end surface (extension surface 12' in Figures 2 to 4). In addition, the difference between the maximum and minimum values of the edge width W is the difference between the maximum and minimum values of the edge width W within the range of 1 mm length (cut length) of the peripheral edge of the surface protection film in the top view.

<End adhesion> The degree of end adhesion resistance of each adhesive layer with a covering film in Examples 1 to 6 and Comparative Examples 1 to 3 was investigated. Specifically, first, 10 evaluation samples of substantially the same size were prepared for each adhesive layer with a covering film, and the 10 evaluation samples were stacked to form a film bundle (Step 1). Then, the front end adhesive surface of a cylindrical rod (diameter 10 mm) having an adhesive surface at the front end was pressed from above against the adhesive layer with a covering film at the top of the film bundle, and the rod was pulled upward to count the number of adhesive layers with a covering film that were lifted as the rod was lifted (Step 2). For each membrane bundle, the test consisting of step 1 and the subsequent step 2 was performed 10 times. Among the 10 tests, the case where the number of tests where only one adhesive layer of the covering film was lifted up with the rod was 10 was evaluated as "excellent", the case where the number of tests was 6 to 9 was evaluated as "good", and the case where the number of tests was 5 or less was evaluated as "poor". The evaluation results are shown in Table 1.

<Paste contamination> As described below, the presence and degree of paste contamination were investigated for the adhesive layers with covering films in Examples 1 to 6 and Comparative Examples 1 to 3.

First, 50 sample films (100 mm × 50 mm) were cut from the adhesive layer attached to the cover film by a cutter. Then, the cut end faces of each sample film were observed visually and under an optical microscope. Then, the ratio (%) of the number of sample films with paste contamination in the cut end faces (paste-contaminated films) relative to the total number of sample films (50) was calculated. Paste contamination refers to the state in which the adhesive overflowing from the adhesive layer adheres to the outer surface of the cover film (surface protection film, peeling pad). Then, regarding the suppression of paste contamination, the case where the ratio of paste contamination to the film was less than 10% was evaluated as "excellent", the case where the ratio of paste contamination to the film was 10% or more and less than 20% was evaluated as "good", and the case where the ratio of paste contamination to the film was 20% or more was evaluated as "poor". The results are shown in Tables 1 and 2.

[Table 1] Table 1 Embodiment 1 Embodiment 2 Embodiment 3 Embodiment 4 Adhesive layer Types of Adhesives A1 A2 A1 A1 Thickness(μm) 25 15 15 25 Gel fraction (%) 70 70 70 70 Shear storage modulus at 25℃(kPa) 27 30 27 27 Maximum shear storage modulus (kPa) 600 4700 600 600 1st shape processing processing method Laser Processing (LC500) Laser Processing (LC500) Laser Processing (LC500) Laser Processing (LC750) Laser output(W) twenty three twenty three twenty three twenty three Pulse frequency(kHz) 15 15 30 30 Position deviation length d(μm) 0 0 0 0 Angle α in the first covering film (°) 46.8 44.4 44.9 53.9 Angle β in adhesive layer (°) 58.4 54.7 52.9 54.7 β/α 1.25 1.23 1.18 1.01 Difference between the maximum and minimum values of edge width W (μm) 2.2 1.8 1.7 2.2 Inhibition of end adhesion Excellent Excellent Excellent Excellent Suppression of paste pollution Excellent Excellent Excellent Excellent

[Table 2] Table 2 Embodiment 5 Embodiment 6 Comparison Example 1 Comparison Example 2 Comparison Example 3 Adhesive layer Types of Adhesives A1 A1 A1 A2 A1 Thickness(μm) 25 25 15 15 15 Gel fraction (%) 70 70 70 70 70 Shear storage modulus at 25℃(kPa) 27 30 27 27 27 Maximum shear storage modulus (kPa) 600 600 600 4700 600 1st shape processing processing method Laser Processing (LC500) Laser Processing (LC500) Punching (blade angle 80°) Punching (blade angle 30°) Punching (blade angle 30°) Laser output(W) twenty three twenty three - - - Pulse frequency(kHz) 30 5 - - - Position deviation length d(μm) 0 1 10 6 15 Angle α in the first covering film (°) 49.1 56.1 88.2 87.6 87.6 Angle β in adhesive layer (°) 49.2 67.3 88.2 87.6 87.6 β/α 1.00 1.20 1.00 1.00 1.00 Difference between the maximum and minimum values of edge width W (μm) 2.2 3.4 14.2 17.6 23.9 Inhibition of end adhesion Excellent good bad bad bad Suppression of paste pollution Excellent good bad bad bad

10: Covering film (first covering film) 11: First surface 12: Film end surface 12': Extension surface 20: Covering film (second covering film) 20A: Extension end 21: Peeling surface 22: Half-cut groove 22a: Inner wall surface 22b: Inner wall surface 22c: Round bottom 30: Adhesive layer 30A: End surface 31: Adhesive surface 32: End surface 60: Laminated sheet 60': Adhesive layer with covering film 61: Peeling pad 61A: Peeling pad 62: Adhesive layer 62a: Peripheral part 62A: Adhesive layer 62e: End 62E: Protrusion 63: Peel-off pad 63a: Peripheral 63A: Peel-off pad 63e: End 65: Cutting site 101: Covering film 101a: Peripheral 102: Covering film 103: Adhesive layer 103a: Peripheral D: Surface direction d: Position offset length d': Extension length H: Thickness direction L: Edge length W: Edge width X: Adhesive layer with covering film Y: Surface protection film with adhesive layer Z: Laminated sheet α: Angle β: Angle

FIG. 1 is a cross-sectional schematic diagram of an embodiment of the adhesive layer with a covering film of the present invention. FIG. 2 is a partially enlarged cross-sectional diagram of an end portion of the adhesive layer with a covering film shown in FIG. 1. FIG. 3 is a partially enlarged cross-sectional diagram of an end portion of a variation of the adhesive layer with a covering film shown in FIG. 1. FIG. 4 is a partially enlarged cross-sectional diagram of an end portion of another variation of the adhesive layer with a covering film shown in FIG. 1. FIG. 5A to FIG. 5D show a method for manufacturing the adhesive layer with a covering film shown in FIG. 1. FIG. 5A shows a laminate sheet manufacturing step, FIG. 5B shows a first shape processing step, FIG. 5C shows a removal step, and FIG. 5D shows a second shape processing step. Fig. 6A to Fig. 6D show an example of a manufacturing method of a previous adhesive layer with a covering film. Fig. 6A shows a laminated sheet manufacturing step, Fig. 6B shows a stamping step, Fig. 6C shows a removal step, and Fig. 6D shows a cutting step. Fig. 7 is a partially enlarged cross-sectional view of an end portion of a previous adhesive layer with a covering film.

10: Covering film (1st covering film)

11: Page 1

12: Membrane end face

20: Covering film (second covering film)

20A: Extended end

21: Peel off the surface

22: Hemisection groove

30: Adhesive layer

30A: End

31: Adhesive surface

32: End face

D: Face direction

H: thickness direction

X: Adhesive layer with covering film

Y: Surface protective film with adhesive layer

Claims (6)

An adhesive layer with a covering film, which has a first covering film, an adhesive layer, and a second covering film in order in the thickness direction, and the first covering film has a first surface 11 located on the side of the adhesive layer and has a film end surface forming an acute angle with the first surface, the second covering film has an extended end portion, and the extended end portion extends to the outside of the end portion of the adhesive layer in a surface direction orthogonal to the thickness direction, and the positional offset length of the end portion of the adhesive layer from the film end surface and the extended surface of the film end surface is less than 5 μm. The adhesive layer with a covering film as claimed in claim 1, wherein the gel fraction of the adhesive layer is less than 80%. The adhesive layer with a covering film as claimed in claim 1, wherein the adhesive layer has a thickness of not less than 5 μm and not more than 50 μm. As in claim 1, the adhesive layer with a covering film, wherein the angle of the sharp angle in the first covering film is greater than 40° and less than 85°. An adhesive layer with a covering film as in claim 4, wherein the adhesive layer has an adhesive surface located on the side of the second covering film and has an adhesive layer end face forming an acute angle with the adhesive surface, and the ratio of the acute angle of the adhesive layer to the acute angle of the first covering film is greater than 0.9 and less than 1.5. The adhesive layer with a cover film as claimed in any one of claims 1 to 5, wherein the difference between the maximum and minimum values of the edge width of the edge representing the edge of the first cover film in a plan view is less than 10 μm.