JP7668643B2 - Adhesive tape for optical components - Google Patents

Description

The present invention relates to an adhesive tape for optical components.

In order to attach two or more adhesive tapes for protecting optical components to an adherend without misalignment, the back sides (opposite the adhesive layer) of the two or more adhesive tapes for protecting optical components are held with a gap by a single holding tape, and the exposed surface of the adhesive layer of the adhesive tape for protecting optical components is protected by a release liner to keep the exposed surface clean. Adhesive tapes for optical components that combine multiple sheets are known (see Patent Documents 1-3). Such adhesive tapes for optical components are used as follows.

First, one release liner protecting the exposed surface of the adhesive layer of two or more optical component protection adhesive tapes is peeled off. Next, the two or more optical component protection adhesive tapes are attached to the adherend while being aligned while being held by one holding tape. Next, the holding tape is peeled off to obtain a state in which two or more optical component protection adhesive tapes are attached to the desired adherend.

Here, when peeling off the release liner from the optical component adhesive tape in the stage before the optical component adhesive tape is applied to the adherend, it is necessary to appropriately adjust the peeling force between the optical component protective adhesive tape and the release liner and the adhesive force between the optical component protective adhesive tape and the holding tape so that peeling does not occur between the optical component protective adhesive tape and the holding tape. On the other hand, when peeling off the holding tape from the optical component adhesive tape in the stage after peeling off the release liner from the optical component adhesive tape and applying it to the adherend, it is necessary to appropriately adjust the adhesive force between the optical component protective adhesive tape and the adherend and the peeling force between the optical component protective adhesive tape and the holding tape so as not to damage the adherend. In designing the optical component adhesive tape, it is necessary to precisely design the adhesive layer provided in the optical component adhesive tape in order to appropriately adjust the adhesive force and peeling force as described above.

Recently, there has been a trend toward thinner components and products that use adhesive tapes for optical components, and there is a demand for thinner adhesive layers in adhesive tapes for protecting optical components.

However, if the adhesive layer of the adhesive tape for protecting optical components is made thinner, there is a risk of an abnormal peeling occurring when peeling off the release liner, in which some of the two or more adhesive tapes for protecting optical components held by the holding tape peel off from the holding tape while still adhering to the release liner.

JP 2017-142375 A JP 2017-212038 A JP 2017-219843 A

The object of the present invention is to provide an adhesive tape for optical components that has a release liner, an adhesive tape for protecting optical components, and a retaining tape in this order, and that can suppress peeling abnormalities when peeling off the release liner even if the adhesive layer of the adhesive tape for protecting optical components is thin.

The pressure-sensitive adhesive tape for optical members according to an embodiment of the present invention comprises:
An adhesive tape for protecting an optical member (I) having an adhesive layer (1) on one surface of a base film (1);
a holding tape (II) directly laminated on the outermost surface of the pressure-sensitive adhesive tape for protecting an optical member (I) on the side opposite to the pressure-sensitive adhesive layer (1);
a release liner (III) laminated directly on an exposed surface of the pressure-sensitive adhesive layer (1) of the pressure-sensitive adhesive tape for protecting optical members (I);
having
Two or more of the pressure-sensitive adhesive tapes for protecting optical components (I) are laminated on one of the holding tapes (II) in a gap-like arrangement,
The thickness of the pressure-sensitive adhesive layer (1) is less than 25 μm,
At least one of the corners formed on the opposing side surfaces of the two adjacent pressure-sensitive adhesive tapes for protecting optical members (I) with the gap therebetween is a chamfered portion.

In one embodiment, the chamfered portion is a C surface, and the chamfered amount of the chamfered portion is C0.05 mm or more.

In one embodiment, the chamfered portion is an R surface, and the chamfered amount of the chamfered portion is R0.05 mm or more.

In one embodiment, the adhesive tape for optical components has a peel force A when peeling off the release liner (III) that is smaller than the adhesive force B when peeling off the holding tape (II) in an environment with a temperature of 23°C and a humidity of 50% RH.

In one embodiment, the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer (1) has a storage modulus G' at 23° C. of 5.0×10 ⁵ Pa or less.

In one embodiment, at least one of the corners formed on both ends of the side surfaces in the longitudinal direction of the two or more optical component protection adhesive tapes (I) stacked in the longitudinal direction of the one holding tape (II) is a chamfered portion.

According to the present invention, in an adhesive tape for optical components having a release liner, an adhesive tape for protecting an optical component, and a retaining tape in this order, it is possible to provide an adhesive tape for optical components that can suppress peeling abnormalities when peeling off the release liner even if the adhesive layer of the adhesive tape for protecting an optical component is thin.

1 is a schematic cross-sectional view of one embodiment of a pressure-sensitive adhesive tape for optical members of the present invention. 1A to 1C are schematic plan views showing several embodiments in which two or more adhesive tapes for protecting optical components (I) are laminated to one holding tape (II) in a gapped arrangement. FIG. 2 is a schematic plan view of one embodiment of a laminate after peeling off a release liner (III) from the pressure-sensitive adhesive tape for optical members according to an embodiment of the present invention, as viewed from the pressure-sensitive adhesive layer (1) side. FIG. 1 is a schematic perspective view showing some embodiments of corners and chamfers that can be formed on the side of an optical member protecting pressure-sensitive adhesive tape (I).

In this specification, "(meth)acrylic" means at least one selected from the group consisting of acrylic and methacrylic, "(meth)acrylate" means at least one selected from the group consisting of acrylate and methacrylate, and "(meth)acryloyl" means at least one selected from the group consisting of acryloyl and methacryloyl.

<<A. Adhesive tape for optical components>>
The adhesive tape for protecting optical components according to an embodiment of the present invention comprises an adhesive tape for protecting optical components (I) having an adhesive layer (1) on one side of a base film (1), a holding tape (II) laminated directly onto the outermost surface of the adhesive tape for protecting optical components (I) opposite the adhesive layer (1), and a release liner (III) laminated directly onto the exposed surface of the adhesive layer (1) of the adhesive tape for protecting optical components (I), and two or more adhesive tapes for protecting optical components (I) are laminated on one holding tape (II) in an arrangement with gaps between them.

In the adhesive tape for optical components according to an embodiment of the present invention, the holding tape (II) typically has an adhesive layer (2) on one side of the base film (2).

Therefore, the adhesive tape for optical components according to the embodiment of the present invention is typically an adhesive tape for optical components, in which an adhesive tape for protecting optical components (I) having an adhesive layer (1) on one side of a base film (1) and a holding tape (II) having an adhesive layer (2) on one side of a base film (2) are directly laminated to the adhesive layer (2) on the outermost side opposite to the adhesive layer (1) of the adhesive tape for protecting optical components (I), and a release liner (III) is directly laminated to the exposed surface of the adhesive layer (1) of the adhesive tape for protecting optical components (I), and two or more adhesive tapes for protecting optical components (I) are laminated to one holding tape (II) in an arrangement with gaps therebetween.

The optical component adhesive tape according to the embodiment of the present invention is as described above, and more simply described, it is a laminate having a release liner (III), an adhesive layer (1), a base film (1), an adhesive layer (2), and a base film (2) in this order, with the least number of layers being 3 or more and the most number of layers being 5 or more, the adhesive layer (1) and the base film (1) being components of an optical component protection adhesive tape (I), the adhesive layer (2) and the base film (2) being components of a holding tape (II), the outermost surface of the optical component protection adhesive tape (I) opposite the adhesive layer (1) and the adhesive layer (2) are directly laminated, the release liner (III) is directly laminated on the exposed surface of the adhesive layer (1), and two or more optical component protection adhesive tapes (I) are laminated on one holding tape (II) with gaps between them.

In the adhesive tape for optical components according to an embodiment of the present invention, each of the release liner (III), adhesive layer (1), base film (1), adhesive layer (2), and base film (2) may consist of only one layer or two or more layers.

The adhesive tape for optical members according to the embodiment of the present invention may have any appropriate other layer as long as it has the above-mentioned configuration and does not impair the effects of the present invention. The other layer may be only one type, or may be two or more types. The total number of other layers may be only one layer, or may be two or more layers. Examples of other layers include an antistatic layer, which will be described later.

The number of layers at the location with the fewest number of layers in the adhesive tape for optical components according to an embodiment of the present invention is preferably 3 to 8 layers, more preferably 3 to 6 layers, even more preferably 3 to 5 layers, particularly preferably 3 to 4 layers, and most preferably 3 layers, depending on the number of other layers described above.

The number of layers at the location with the greatest number of layers in the adhesive tape for optical components according to an embodiment of the present invention is preferably 5 to 10 layers, more preferably 5 to 8 layers, even more preferably 5 to 7 layers, particularly preferably 5 to 6 layers, and most preferably 5 layers, depending on the number of other layers described above.

As shown in FIG. 1, one embodiment of the adhesive tape for optical components of the present invention is an adhesive tape for optical components 1000 in which a release liner (III) 30, an adhesive layer (1) 11, a base film (1) 12, an adhesive layer (2) 21, and a base film (2) 22 are directly laminated in this order, the adhesive layer (1) 11 and the base film (1) 12 constitute an adhesive tape for protecting an optical component (I) 100, the adhesive layer (2) 21 and the base film (2) 22 constitute a holding tape (II) 200, and two or more adhesive tapes for protecting an optical component (I) (two adhesive tapes for protecting an optical component (I) 101, 102 in the embodiment of FIG. 1) are laminated on one holding tape (II) 200 with a gap therebetween.

The shape of the holding tape (II) may be any appropriate shape as long as it is a thick tape (also called a sheet) and does not impair the effects of the present invention. A typical example of such a shape is one in which the long side and short side are in the longitudinal direction and width direction, respectively, which are substantially perpendicular to each other.

The shape of the pressure-sensitive adhesive tape (I) for protecting optical components may be any appropriate shape as long as it is a thick tape (also called a sheet) and does not impair the effects of the present invention. Any appropriate shape may be adopted in accordance with the shape of the adherend. A typical example of such a shape is one in which the long side and short side are in the longitudinal direction and width direction, respectively, which are substantially perpendicular to each other.

The two or more optical component protection adhesive tapes (I) in the optical component adhesive tape of the present invention may be the same size, or at least two of them may be different sizes.

Among the two or more adhesive tapes (I) for protecting optical components, the distance L between two adjacent adhesive tapes (I) for protecting optical components with a gap therebetween is preferably 0.1 mm to 5.0 mm, more preferably 0.2 mm to 3.0 mm, even more preferably 0.3 mm to 2.0 mm, particularly preferably 0.5 mm to 1.5 mm, and most preferably 0.7 mm to 1.5 mm.

In the adhesive tape for optical components according to an embodiment of the present invention, the number of adhesive tapes (I) for protecting optical components laminated to one holding tape (II) in a gap-free arrangement may be two, or three or more.

In the optical component adhesive tape according to the embodiment of the present invention, at least two of the two or more optical component protection adhesive tapes (I) laminated in a gap-free arrangement on one holding tape (II) are typically arranged along the longitudinal direction of the holding tape (II). When two optical component protection adhesive tapes (I) are laminated in a gap-free arrangement on one holding tape (II), as shown in the schematic plan view of FIG. 2(a), two optical component protection adhesive tapes (I) 101 and 102 are laminated in a gap-free arrangement on one holding tape (II) 200 along the longitudinal direction of the holding tape (II). When three adhesive tapes (I) for protecting optical components are laminated to one holding tape (II) in a gapped arrangement, the three adhesive tapes (I) for protecting optical components 101, 102, and 103 may be arranged on one holding tape (II) 200, for example, as shown in the schematic plan view of FIG. 2(b), or as shown in the schematic plan view of FIG. 2(c).

In the adhesive tape for optical components according to the embodiment of the present invention, the thickness of the adhesive layer (1) is thin, typically less than 30 μm, preferably 28 μm or less, more preferably 26 μm or less, even more preferably 21 μm or less, and particularly preferably 16 μm or less. The lower limit of the thickness of the adhesive layer (1) is preferably 5 μm or more, more preferably 8 μm or more, even more preferably 10 μm or more, and particularly preferably 12 μm or more. If the thickness of the adhesive layer (1) is within the above range, it is possible to respond to the thinning of the target components and products in which the adhesive tape for optical components according to the embodiment of the present invention is used, while maintaining the adhesive performance required of the adhesive layer (1).

In the adhesive tape for optical components according to an embodiment of the present invention, the release liner (III), the adhesive layer (1), the base film (1), the adhesive layer (2), and the base film (2) may each have an antistatic layer on at least one surface.

In the adhesive tape for optical components according to an embodiment of the present invention, the adhesive tape for protecting optical components (I) may have an antistatic layer on at least one surface.

In the adhesive tape for optical components according to an embodiment of the present invention, the holding tape (II) may have an antistatic layer on at least one surface thereof.

In the pressure-sensitive adhesive tape for optical members according to an embodiment of the present invention, the pressure-sensitive adhesive layer (1) may contain a conductive component. The conductive component may be of only one type, or of two or more types.

In the pressure-sensitive adhesive tape for optical members according to an embodiment of the present invention, the pressure-sensitive adhesive layer (2) may contain a conductive component. The conductive component may be of only one type, or of two or more types.

In the optical member adhesive tape according to an embodiment of the present invention, at least one of the corners formed on the opposing side surfaces of the two adjacent optical member protection adhesive tapes (I) with a gap therebetween is a chamfered portion. FIG. 3 is a schematic plan view of one embodiment of a laminate after peeling off the release liner (III) from the optical member protection adhesive tape according to an embodiment of the present invention, as viewed from the adhesive layer (1). In FIG. 3, two optical member protection adhesive tapes (I) 101 and 102 are laminated on one holding tape (II) 200 in an arrangement with a gap therebetween. In FIG. 3, the two optical member protection adhesive tapes (I) 101 and 102 are adjacent to each other with a gap therebetween, and the optical member protection adhesive tape (I) 101 has corners 1a, 1b, 1c, and 1d on its side surface, and the optical member protection adhesive tape (I) 102 has corners 2a, 2b, 2c, and 2d on its side surface. In Figure 3, among these corners, corners 1a, 1b, 2c, and 2d correspond to corners formed on the opposing side surfaces of the two optical component protection adhesive tapes (I) 101 and 102. Therefore, in Figure 3, at least one of corners 1a, 1b, 2c, and 2d formed on the opposing side surfaces of the two optical component protection adhesive tapes (I) 101 and 102 is a chamfered portion.

As mentioned above, when the adhesive layer of the conventional optical component protection adhesive tape is thinned, some of the two or more optical component protection adhesive tapes held by the holding tape peel off from the holding tape in a state of adhering to the release liner when the release liner is peeled off, which causes a major problem such as a decrease in yield. In the optical component protection adhesive tape according to the embodiment of the present invention, at least one of the corners formed on the opposing sides of the two adjacent optical component protection adhesive tapes (I) with a gap therebetween is a chamfered portion, so that when the release liner (III) is peeled off, the two or more optical component protection adhesive tapes (I) stacked in a gap-equipped arrangement on one holding tape (II) can be reliably peeled off at the interface between the release liner (III) and the optical component protection adhesive tape (I) while being well held by the holding tape (II). This is because at least one of the corners formed on the opposing sides of two adjacent adhesive tapes for protecting optical components (I) separated by a gap is a chamfered portion, so that when the release liner (III) is peeled off, the force that causes the release liner (III) to separate from the adhesive tape for protecting optical components (I) and the force that causes the adhesive tape for protecting optical components (I) to separate from the holding tape (II) can act in an appropriate balance, suppressing the occurrence of conventional peeling abnormalities.

In FIG. 3, the two adhesive tapes (I) 101 and 102 for protecting optical components are substantially rectangular in shape, with the long sides being the longitudinal and short sides being the width directions that are perpendicular to each other, and therefore each has four corners on its side. However, if the adhesive tape (I) for protecting optical components is not rectangular in shape as described above, the number of corners may be less than four or may be five or more.

The shape of the chamfered portion may be any appropriate shape as long as it does not impair the effects of the present invention. In order to more effectively exert the effects of the present invention, the chamfered portion is preferably at least one selected from a C-face and an R-face.

When the chamfered portion is a C-surface, the chamfering amount of the chamfered portion is preferably C0.05 mm or more, more preferably C0.05 mm to C5 mm, even more preferably C0.1 mm to C1 mm, and particularly preferably C0.15 mm to C0.5 mm, in order to further demonstrate the effects of the present invention.

When the chamfered portion is an R surface, the chamfering amount of the chamfered portion is preferably R0.05 mm or more, more preferably R0.05 mm to R5 mm, even more preferably R0.1 to R1 mm, and particularly preferably R0.15 mm to R0.5 mm, in order to further demonstrate the effects of the present invention.

Figure 4 is a schematic perspective view showing several embodiments of corners and chamfers that can be formed on the side of the adhesive tape (I) for protecting optical components.

Figure 4(a) shows an optical member protecting adhesive tape (I) 101 having four corners 1a, 1b, 1c, and 1d. In Figure 4(a), the optical member protecting adhesive tape (I) 101 has a front surface 10, a back surface 20, and side surfaces 40, 50, 60, and 70, with side surface 40 and side surface 50 forming corner 1a, side surface 50 and side surface 60 forming corner 1b, side surface 60 and side surface 70 forming corner 1c, and side surface 70 and side surface 40 forming corner 1d. None of the four corners 1a, 1b, 1c, and 1d in Figure 4(a) are chamfered.

Figure 4(b) shows the optical member protection adhesive tape (I) 101 shown in Figure 4(a) with the corners 1a and 1b chamfered at the C-side, and includes chamfered portions 1Ca, 1Cb, corners 1c, and 1d.

Figure 4(c) shows the corners 1a and 1b of the optical component protection adhesive tape (I) 101 shown in Figure 4(a) that have been chamfered, and includes chamfered portion 1Ra, chamfered portion 1Rb, corner portion 1c, and corner portion 1d.

In the adhesive tape for optical components according to the embodiment of the present invention, in order to more effectively exhibit the effects of the present invention, preferably, at least one of the corners formed on both ends of the side surfaces in the longitudinal direction of the two or more adhesive tapes for protecting optical components (I) stacked in the longitudinal direction of one holding tape (II) is a chamfered portion. In the embodiment shown in FIG. 3, for example, the corners formed on both ends of the side surfaces in the longitudinal direction correspond to corners 1c, 1d, 2a, and 2b of the two adhesive tapes for protecting optical components (I) 101 and 102. If at least one of the corners formed on both ends of the longitudinal side of two or more adhesive tapes (I) for protecting optical components stacked in the longitudinal direction of one holding tape (II) is a chamfered portion, when peeling off the release liner (III), the force that causes the release liner (III) to separate from the adhesive tape for protecting optical components (I) and the force that causes the adhesive tape for protecting optical components (I) to separate from the holding tape (II) can act in an appropriate balance, further suppressing the occurrence of conventional peeling abnormalities.

In the adhesive tape for optical members according to the embodiment of the present invention, the peel force A when peeling off the release liner (III) in an environment of a temperature of 23°C and a humidity of 50% RH is preferably 0.15 N/25 mm or less, more preferably 0.001 N/25 mm to 0.10 N/25 mm, even more preferably 0.005 N/25 mm to 0.07 N/25 mm, and particularly preferably 0.01 N/25 mm to 0.05 N/25 mm. By adjusting the peel force A within the above range, peeling is unlikely to occur between the adhesive tape for protecting optical members and the holding tape when peeling off the release liner from the adhesive tape for optical members. Details of the method for measuring the peel force A will be described later.

In the adhesive tape for optical members according to the embodiment of the present invention, the adhesive strength B when peeling off the holding tape (II) in an environment of a temperature of 23° C. and a humidity of 50% RH is preferably 1.00 N/25 mm or less, more preferably 0.01 N/25 mm to 0.50 N/25 mm, even more preferably 0.02 N/25 mm to 0.30 N/25 mm, and particularly preferably 0.02 N/25 mm to 0.10 N/25 mm. By adjusting the adhesive strength B within the above range, if it is below the upper limit, it is possible to prevent damage to the adherend when peeling off the holding tape from the adhesive tape for optical members attached to the adherend by peeling off the release liner, and if it is above the lower limit, it is possible to prevent unexpected peeling during transportation. Details of the method for measuring the adhesive strength B will be described later.

In the adhesive tape for optical components according to the embodiment of the present invention, the peeling force A is preferably smaller than the adhesive force B with respect to the peeling force A and the adhesive force B. By adjusting the peeling force A to be smaller than the adhesive force B, peeling is less likely to occur between the adhesive tape for protecting optical components and the retaining tape when the release liner is peeled off from the adhesive tape for optical components, and damage to the adherend can be prevented when the release liner is peeled off and the retaining tape is peeled off from the adhesive tape for optical components attached to the adherend.

In the pressure-sensitive adhesive tape for optical members according to an embodiment of the present invention, the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer (1) preferably has a storage modulus G' at 23° C. of 5.0×10 ⁵ Pa or less, more preferably 1.0×10 ⁴ Pa to 3.0×10 ⁵ Pa, even more preferably 1.0×10 ⁴ Pa to 2.0×10 ⁵ Pa, and particularly preferably 1.0×10 ⁴ Pa to 1.0×10 ⁵ Pa. When the storage modulus G' at 23° C. of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer (1) is within the above range, the effects of the present invention can be more effectively exhibited.

The adhesive tape for optical components according to an embodiment of the present invention preferably has a total light transmittance of 20% or more, more preferably 30% to 100%, even more preferably 50% to 100%, particularly preferably 83% to 100%, and most preferably 85% to 100%. The method for measuring the total light transmittance will be described later.

The adhesive tape for optical components according to an embodiment of the present invention preferably has a haze of 20% or less, more preferably 0% to 20%, even more preferably 0% to 15%, particularly preferably 0% to 12%, and most preferably 0% to 10%. The method for measuring the haze will be described later.

The adhesive tape for optical components according to the embodiment of the present invention can be used for various applications. In order to more effectively utilize the effects of the present invention, the adhesive tape for optical components according to the embodiment of the present invention is preferably for application to a foldable or rollable component. In this case, a representative example of a foldable or rollable component is an OLED.

<A-1. Release liner (III)>
The thickness of the release liner (III) is preferably 1 μm to 300 μm, more preferably 10 μm to 200 μm, even more preferably 20 μm to 150 μm, particularly preferably 35 μm to 100 μm, and most preferably 50 μm to 80 μm, so that the effects of the present invention can be more effectively exhibited. If the thickness of the release liner (III) is too small compared to the above range, the curl suppression effect may be reduced. If the thickness of the release liner (III) is too large compared to the above range, there is a risk that the pressure-sensitive adhesive tape for optical members according to the embodiment of the present invention may be more likely to lift when bent.

The release liner (III) includes a resin substrate film (IIIa).

Examples of the resin substrate film (IIIa) include plastic films made of polyester-based resins such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate (PBT); plastic films made of olefin-based resins containing α-olefins as monomer components, such as polyethylene (PE), polypropylene (PP), polymethylpentene (PMP), ethylene-propylene copolymer, and ethylene-vinyl acetate copolymer (EVA); plastic films made of polyvinyl chloride (PVC); plastic films made of vinyl acetate-based resins; plastic films made of polycarbonate (PC); and plastic films made of polyphenylene sulfide (PPS). ); plastic films made of amide-based resins such as polyamide (nylon) and fully aromatic polyamide (aramid); plastic films made of polyimide-based resins; plastic films made of polyether ether ketone (PEEK); plastic films made of olefin-based resins such as polyethylene (PE) and polypropylene (PP); plastic films made of fluorine-based resins such as polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, and chlorofluoroethylene-vinylidene fluoride copolymer; and the like.

The resin substrate film (IIIa) may be a single layer or may be two or more layers. The resin substrate film (IIIa) may be stretched.

The resin substrate film (IIIa) may be subjected to a surface treatment. Examples of the surface treatment include corona treatment, plasma treatment, chromate treatment, ozone exposure, flame exposure, high-voltage shock exposure, ionizing radiation treatment, and coating treatment with a primer.

The resin substrate film (IIIa) may contain any suitable additives as long as they do not impair the effects of the present invention.

The release liner (III) may have a release layer (IIIb) to improve releasability from the adhesive layer (1). When the release liner (III) has a release layer (IIIb), typically the side of the release layer (IIIb) is laminated directly onto the adhesive layer (1).

Any suitable forming material may be used for the release layer (IIIb) as long as it does not impair the effects of the present invention. Examples of such forming materials include silicone-based release agents, fluorine-based release agents, long-chain alkyl-based release agents, and fatty acid amide-based release agents. Among these, silicone-based release agents are preferred. The release layer (IIIb) can be formed as a coating layer.

The thickness of the release layer (IIIb) may be any appropriate thickness depending on the purpose, as long as it does not impair the effects of the present invention. Such a thickness is preferably 10 nm to 2000 nm, more preferably 10 nm to 1500 nm, even more preferably 10 nm to 1000 nm, and particularly preferably 10 nm to 500 nm.

The release layer (IIIb) may consist of only one layer, or two or more layers.

Examples of the silicone-based release layer include addition reaction type silicone resins. Specific examples of the addition reaction type silicone resins include KS-774, KS-775, KS-778, KS-779H, KS-847H, and KS-847T manufactured by Shin-Etsu Chemical Co., Ltd.; TPR-6700, TPR-6710, and TPR-6721 manufactured by Toshiba Silicone; and SD7220 and SD7226 manufactured by Toray Dow Corning Co., Ltd. The coating amount (after drying) of the silicone-based release layer is preferably 0.01 g/m ² to 2 g/m ² , more preferably 0.01 g/m ² to 1 g/m ² , and even more preferably 0.01 g/m ² to 0.5 g/m ² .

The release layer (IIIb) can be formed, for example, by applying the above-mentioned forming material onto any suitable layer by a conventionally known application method such as reverse gravure coating, bar coating, or die coating, and then curing the applied material by heat treatment, usually at about 120 to 200°C. If necessary, heat treatment and irradiation with active energy rays such as ultraviolet light may be used in combination.

The release liner (III) may have an antistatic layer (IIIc).

The thickness of the antistatic layer (IIIc) may be any appropriate thickness as long as it does not impair the effects of the present invention. Such a thickness is preferably 1 nm to 1000 nm, more preferably 5 nm to 900 nm, even more preferably 7.5 nm to 800 nm, and particularly preferably 10 nm to 700 nm.

The antistatic layer (IIIc) may consist of only one layer, or two or more layers.

As the antistatic layer (IIIc), any suitable antistatic layer may be used as long as it has an antistatic effect and does not impair the effects of the present invention. Such an antistatic layer is preferably an antistatic layer formed by coating a conductive coating liquid containing a conductive polymer on any suitable substrate layer. Specifically, for example, an antistatic layer formed by coating a conductive coating liquid containing a conductive polymer on a resin substrate film (IIIa). Specific coating methods include roll coating, bar coating, and gravure coating.

As the conductive polymer, any suitable conductive polymer may be used as long as it does not impair the effects of the present invention. Examples of such conductive polymers include conductive polymers in which a π-conjugated conductive polymer is doped with a polyanion. Examples of the π-conjugated conductive polymer include chain-like conductive polymers such as polythiophene, polypyrrole, polyaniline, and polyacetylene. Examples of the polyanion include polystyrene sulfonic acid, polyisoprene sulfonic acid, polyvinyl sulfonic acid, polyallyl sulfonic acid, polyethyl acrylate sulfonic acid, and polymethacrylic carboxylic acid. The conductive polymer may be of only one type, or of two or more types.

One embodiment of the release liner (III) includes a resin substrate film (IIIa) and a release layer (IIIb) in this order. Typically, this embodiment consists of a resin substrate film (IIIa) and a release layer (IIIb).

One embodiment of the release liner (III) includes a resin substrate film (IIIa), an antistatic layer (IIIc), and a release layer (IIIb) in this order. Typically, this embodiment includes a resin substrate film (IIIa), an antistatic layer (IIIc), and a release layer (IIIb).

Another embodiment of the release liner (III) includes an antistatic layer (IIIc), a resin substrate film (IIIa), an antistatic layer (IIIc), and a release layer (IIIb) in this order. Typically, this embodiment includes an antistatic layer (IIIc), a resin substrate film (IIIa), an antistatic layer (IIIc), and a release layer (IIIb).

<A-2. Pressure-sensitive adhesive layer (1)>
Any appropriate pressure-sensitive adhesive layer can be adopted as the pressure-sensitive adhesive layer (1) as long as the effects of the present invention are not impaired. The pressure-sensitive adhesive layer (1) may be a single layer or may be two or more layers.

The thickness of the adhesive layer (1) is typically less than 30 μm, preferably 28 μm or less, more preferably 26 μm or less, even more preferably 21 μm or less, and particularly preferably 16 μm or less, so as to better exhibit the effects of the present invention. The lower limit of the thickness of the adhesive layer (1) is preferably 5 μm or more, more preferably 8 μm or more, even more preferably 10 μm or more, and particularly preferably 12 μm or more. If the thickness of the adhesive layer (1) is within the above range, it can accommodate the thinning of target members and products in which the adhesive tape for optical components according to the embodiment of the present invention is used, while maintaining the adhesive performance required of the adhesive layer (1).

The adhesive layer (1) is preferably composed of at least one selected from the group consisting of an acrylic adhesive (1), a urethane adhesive (1), a rubber adhesive (1), and a silicone adhesive (1). The adhesive layer (1) is more preferably an acrylic adhesive (1) in that it can more effectively exert the effects of the present invention.

The adhesive layer (1) may be formed by any suitable method. For example, an adhesive composition (at least one selected from the group consisting of an acrylic adhesive composition (1), a urethane adhesive composition (1), a rubber adhesive composition (1), and a silicone adhesive composition (1)) that forms the adhesive constituting the adhesive layer (1) may be applied to any suitable substrate (for example, a substrate film (1)), heated and dried as necessary, and cured as necessary to form an adhesive layer on the substrate. Examples of such application methods include a gravure roll coater, a reverse roll coater, a kiss roll coater, a dip roll coater, a bar coater, a knife coater, an air knife coater, a spray coater, a comma coater, a direct coater, and a roll brush coater.

The adhesive layer (1) may contain other components (1). The other components (1) may be one type or two or more types. Any appropriate other components may be used as the other components (1) as long as they do not impair the effects of the present invention. Examples of such other components (1) include other polymer components, crosslinking accelerators, crosslinking catalysts, silane coupling agents, tackifier resins (rosin derivatives, polyterpene resins, petroleum resins, oil-soluble phenols, etc.), anti-aging agents, inorganic fillers, organic fillers, metal powders, colorants (pigments, dyes, etc.), foil-like materials, ultraviolet absorbers, antioxidants, light stabilizers, chain transfer agents, plasticizers, softeners, surfactants, conductive components, stabilizers, surface lubricants, leveling agents, corrosion inhibitors, heat stabilizers, polymerization inhibitors, lubricants, solvents, catalysts, etc.

Representative examples of the other components (1) include conductive components. The conductive components may be of only one type, or may be of two or more types. Any appropriate conductive component may be used as the conductive component as long as it does not impair the effects of the present invention. Examples of such conductive components include ionic liquids, ion-conducting polymers, ion-conducting fillers, and electrically conductive polymers.

<A-2-1. Acrylic adhesive (1)>
The pressure-sensitive adhesive layer (1) is preferably composed of an acrylic pressure-sensitive adhesive (1).

The acrylic adhesive (1) is formed from an acrylic adhesive composition (1).

The acrylic adhesive composition (1) contains a (meth)acrylic resin (1). The (meth)acrylic resin (1) may be of only one type or of two or more types.

The content of (meth)acrylic resin (1) in the acrylic adhesive composition (1) is preferably 60% by weight to 99.9% by weight, more preferably 65% by weight to 99.9% by weight, even more preferably 70% by weight to 99.9% by weight, particularly preferably 75% by weight to 99.9% by weight, and most preferably 80% by weight to 99.9% by weight, calculated on a solid content basis.

As the (meth)acrylic resin (1), any suitable (meth)acrylic resin may be used as long as it does not impair the effects of the present invention.

The weight average molecular weight of the (meth)acrylic resin (1) is preferably 300,000 to 2,500,000, more preferably 350,000 to 2,000,000, even more preferably 400,000 to 1,800,000, and particularly preferably 500,000 to 1,500,000, in order to further exert the effects of the present invention.

The acrylic adhesive composition (1) may contain a crosslinking agent. By using a crosslinking agent, the cohesive strength of the acrylic adhesive (1) can be improved, and the effects of the present invention can be more effectively achieved. The crosslinking agent may be one type only, or two or more types.

Examples of crosslinking agents include polyfunctional isocyanate-based crosslinking agents, epoxy-based crosslinking agents, melamine-based crosslinking agents, peroxide-based crosslinking agents, urea-based crosslinking agents, metal alkoxide-based crosslinking agents, metal chelate-based crosslinking agents, metal salt-based crosslinking agents, carbodiimide-based crosslinking agents, oxazoline-based crosslinking agents, aziridine-based crosslinking agents, and amine-based crosslinking agents. Among these, at least one selected from the group consisting of polyfunctional isocyanate-based crosslinking agents and epoxy-based crosslinking agents is preferred in terms of being able to further exert the effects of the present invention.

Examples of polyfunctional isocyanate crosslinking agents include lower aliphatic polyisocyanates such as 1,2-ethylene diisocyanate, 1,4-butylene diisocyanate, and 1,6-hexamethylene diisocyanate; alicyclic polyisocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, and hydrogenated xylene diisocyanate; and aromatic polyisocyanates such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and xylylene diisocyanate. Examples of polyfunctional isocyanate crosslinking agents include commercially available products such as trimethylolpropane/tolylene diisocyanate adduct (manufactured by Nippon Polyurethane Industry Co., Ltd., product name "Coronate L"), trimethylolpropane/hexamethylene diisocyanate adduct (manufactured by Nippon Polyurethane Industry Co., Ltd., product name "Coronate HL"), product name "Coronate HX" (Nippon Polyurethane Industry Co., Ltd.), and trimethylolpropane/xylylene diisocyanate adduct (manufactured by Mitsui Chemicals, Inc., product name "Takenate 110N").

Examples of epoxy crosslinking agents (multifunctional epoxy compounds) include N,N,N',N'-tetraglycidyl-m-xylylenediamine, diglycidylaniline, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, sorbitol polyglycidyl ether, and ethylene glycol diglycidyl ether. Examples of epoxy crosslinking agents include diglycidyl ether, glycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitan polyglycidyl ether, trimethylolpropane polyglycidyl ether, adipic acid diglycidyl ester, o-phthalic acid diglycidyl ester, triglycidyl-tris(2-hydroxyethyl)isocyanurate, resorcinol diglycidyl ether, bisphenol-S-diglycidyl ether, and epoxy resins having two or more epoxy groups in the molecule. Examples of epoxy crosslinking agents include commercially available products such as "Tetrad C" (manufactured by Mitsubishi Gas Chemical Co., Ltd.).

The content of the crosslinking agent in the acrylic adhesive composition (1) may be any appropriate content within the range that does not impair the effects of the present invention. For example, such a content is preferably 30 parts by weight or less, more preferably 0.05 parts by weight to 20 parts by weight, even more preferably 0.1 parts by weight to 18 parts by weight, particularly preferably 0.5 parts by weight to 15 parts by weight, and most preferably 0.5 parts by weight to 10 parts by weight, relative to the solid content (100 parts by weight) of the (meth)acrylic resin (1), in terms of being able to further exhibit the effects of the present invention.

The acrylic adhesive composition (1) may contain any other appropriate components within the scope of the present invention, so long as the effects of the present invention are not impaired. Examples of such other components include polymer components other than the (meth)acrylic resin (1), crosslinking accelerators, crosslinking catalysts, silane coupling agents, tackifier resins (rosin derivatives, polyterpene resins, petroleum resins, oil-soluble phenols, etc.), anti-aging agents, inorganic fillers, organic fillers, metal powders, colorants (pigments, dyes, etc.), foil-like materials, UV absorbers, antioxidants, light stabilizers, chain transfer agents, plasticizers, softeners, surfactants, antistatic agents, conductive agents, stabilizers, surface lubricants, leveling agents, corrosion inhibitors, heat stabilizers, polymerization inhibitors, lubricants, solvents, catalysts, etc.

[A-2-1-1. Preferred embodiment 1 of (meth)acrylic resin (1)]
A preferred embodiment 1 of the (meth)acrylic resin (1), from the viewpoint of further exerting the effects of the present invention, is a (meth)acrylic resin (A) formed by polymerization from a composition (A) containing: (component a) a (meth)acrylic acid alkyl ester in which the alkyl ester moiety has an alkyl group having 1 to 12 carbon atoms; and (component b) at least one selected from the group consisting of a (meth)acrylic acid ester having an OH group and (meth)acrylic acid.

As the (meth)acrylic resin (A), in terms of being able to further exert the effects of the present invention, it is preferable that the (meth)acrylic resin (A) is formed by polymerization from a composition (A) containing, as the (a) component, a (meth)acrylic acid alkyl ester having 1 to 12 carbon atoms in the alkyl group of the alkyl ester portion, and as the (b) component, (meth)acrylic acid without containing a (meth)acrylic acid ester having an OH group. More preferable is a (meth)acrylic resin (A) formed by polymerization from a composition (A) containing, as the (a) component, a (meth)acrylic acid alkyl ester having 1 to 8 carbon atoms in the alkyl group of the alkyl ester portion, and as the (b) component, acrylic acid without containing a (meth)acrylic acid ester having an OH group. Even more preferable is a (meth)acrylic resin (A) formed by polymerization from a composition (A) containing, as the (a) component, a (meth)acrylic acid alkyl ester having 1 to 6 carbon atoms in the alkyl group of the alkyl ester portion, and as the (b) component, acrylic acid without containing a (meth)acrylic acid ester having an OH group.

(Component a) and (Component b) may each independently be one type or two or more types.

Examples of (meth)acrylic acid alkyl esters (component a) in which the alkyl group in the alkyl ester portion has 1 to 12 carbon atoms include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, and dodecyl (meth)acrylate. Among these, in terms of being able to more effectively exert the effects of the present invention, methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate are preferred, and methyl acrylate, ethyl acrylate, n-butyl acrylate, and 2-ethylhexyl acrylate are more preferred.

At least one type (component b) selected from the group consisting of (meth)acrylic acid esters having an OH group and (meth)acrylic acid includes, for example, (meth)acrylic acid esters having an OH group, such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate, and (meth)acrylic acid. Among these, hydroxyethyl (meth)acrylate and (meth)acrylic acid are preferred, and hydroxyethyl acrylate and acrylic acid are more preferred, in terms of being able to more effectively exert the effects of the present invention.

The composition (A) may contain a copolymerizable monomer other than the components (a) and (b). The copolymerizable monomer may be of only one type, or of two or more types. Examples of such copolymerizable monomers include (meth)acrylic acid alkyl esters in which the alkyl group in the alkyl ester portion has 1 to 3 carbon atoms; carboxyl group-containing monomers (excluding (meth)acrylic acid) such as itaconic acid, maleic acid, fumaric acid, crotonic acid, isocrotonic acid, and acid anhydrides thereof (e.g., acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride); (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-methylol(meth)acrylamide, N-methoxymethyl(meth)acrylamide, N amide group-containing monomers such as N-butoxymethyl(meth)acrylamide and N-hydroxyethyl(meth)acrylamide; amino group-containing monomers such as aminoethyl(meth)acrylate, dimethylaminoethyl(meth)acrylate and t-butylaminoethyl(meth)acrylate; epoxy group-containing monomers such as glycidyl(meth)acrylate and methylglycidyl(meth)acrylate; cyano group-containing monomers such as acrylonitrile and methacrylonitrile; N-vinyl-2-pyrrolidone, (meth)acryloylmorpholine, N-vinylpiperidone, N-vinyl Heterocycle-containing vinyl monomers such as piperazine, N-vinylpyrrole, N-vinylimidazole, vinylpyridine, vinylpyrimidine, and vinyloxazole; sulfonic acid group-containing monomers such as sodium vinyl sulfonate; phosphoric acid group-containing monomers such as 2-hydroxyethyl acryloyl phosphate; imide group-containing monomers such as cyclohexylmaleimide and isopropylmaleimide; isocyanate group-containing monomers such as 2-methacryloyloxyethyl isocyanate; cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate (meth)acrylic acid esters having an alicyclic hydrocarbon group such as phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, benzyl (meth)acrylate, etc.; (meth)acrylic acid esters having an aromatic hydrocarbon group such as phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, benzyl (meth)acrylate, etc.; vinyl esters such as vinyl acetate, vinyl propionate, etc.; aromatic vinyl compounds such as styrene, vinyl toluene, etc.; olefins and dienes such as ethylene, butadiene, isoprene, isobutylene, etc.; vinyl ethers such as vinyl alkyl ethers; vinyl chloride, etc.

As the copolymerizable monomer, a polyfunctional monomer may also be used. A polyfunctional monomer refers to a monomer having two or more ethylenically unsaturated groups in one molecule. As the ethylenically unsaturated group, any appropriate ethylenically unsaturated group may be used as long as it does not impair the effects of the present invention. Examples of such ethylenically unsaturated groups include radically polymerizable functional groups such as vinyl groups, propenyl groups, isopropenyl groups, vinyl ether groups (vinyloxy groups), and allyl ether groups (allyloxy groups). Examples of polyfunctional monomers include hexanediol di(meth)acrylate, butanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, trimethylolpropane tri(meth)acrylate, tetramethylolmethane tri(meth)acrylate, allyl (meth)acrylate, vinyl (meth)acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, urethane acrylate, etc. Such polyfunctional monomers may be used alone or in combination of two or more kinds.

As the copolymerizable monomer, (meth)acrylic acid alkoxyalkyl esters may also be used. Examples of (meth)acrylic acid alkoxyalkyl esters include 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, 3-methoxypropyl (meth)acrylate, 3-ethoxypropyl (meth)acrylate, 4-methoxybutyl (meth)acrylate, and 4-ethoxybutyl (meth)acrylate. Only one type of (meth)acrylic acid alkoxyalkyl ester may be used, or two or more types may be used.

The content of the (meth)acrylic acid alkyl ester (component a) in which the alkyl group in the alkyl ester portion has 1 to 12 carbon atoms is preferably 30% by weight or more, more preferably 35% to 99% by weight, even more preferably 40% to 98% by weight, and particularly preferably 50% to 95% by weight, based on the total amount (100% by weight) of the monomer components constituting the (meth)acrylic resin (A), in order to further exert the effects of the present invention.

In order to further exert the effects of the present invention, the content of (meth)acrylic acid alkyl esters in which the alkyl group in the alkyl ester moiety has 2 to 12 carbon atoms (preferably 2 to 10, more preferably 2 to 8, and even more preferably 2 to 6) in the total amount (100% by weight) of (meth)acrylic acid alkyl esters (component a) in which the alkyl group in the alkyl ester moiety has 1 to 12 carbon atoms is preferably 30% by weight or more, more preferably 35% by weight to 100% by weight, even more preferably 40% by weight to 100% by weight, and particularly preferably 45% by weight to 100% by weight.

The content of at least one selected from the group consisting of (meth)acrylic acid esters having an OH group and (meth)acrylic acid (component b) is preferably 1% by weight or more, more preferably 1 to 30% by weight, even more preferably 2 to 20% by weight, and particularly preferably 3 to 15% by weight, based on the total amount (100% by weight) of the monomer components constituting the (meth)acrylic resin (A), in order to further exert the effects of the present invention.

Composition (A) may contain any appropriate other components as long as the effects of the present invention are not impaired. Examples of such other components include a polymerization initiator, a chain transfer agent, and a solvent. The content of these other components may be any appropriate content as long as the effects of the present invention are not impaired.

The polymerization initiator may be a thermal polymerization initiator or a photopolymerization initiator (photoinitiator), depending on the type of polymerization reaction. There may be only one type of polymerization initiator, or two or more types.

The thermal polymerization initiator may be preferably used when obtaining the (meth)acrylic resin (A) by solution polymerization. Examples of such thermal polymerization initiators include azo-based polymerization initiators, peroxide-based polymerization initiators (e.g., dibenzoyl peroxide, tert-butyl permaleate, etc.), and redox-based polymerization initiators. Among these thermal polymerization initiators, the azo-based initiators disclosed in JP-A-2002-69411 are particularly preferred. Such azo-based polymerization initiators are preferred in that decomposition products of the polymerization initiator are unlikely to remain in the (meth)acrylic resin (A) as a portion that causes the generation of gas generated by heating (outgassing). Examples of azo polymerization initiators include 2,2'-azobisisobutyronitrile (hereinafter sometimes referred to as AIBN), 2,2'-azobis-2-methylbutyronitrile (hereinafter sometimes referred to as AMBN), 2,2'-azobis(2-methylpropionate) dimethyl, and 4,4'-azobis-4-cyanovaleric acid.

The photopolymerization initiator may be preferably used when obtaining the (meth)acrylic resin (A) by active energy ray polymerization. Examples of the photopolymerization initiator include benzoin ether-based photopolymerization initiators, acetophenone-based photopolymerization initiators, α-ketol-based photopolymerization initiators, aromatic sulfonyl chloride-based photopolymerization initiators, photoactive oxime-based photopolymerization initiators, benzoin-based photopolymerization initiators, benzyl-based photopolymerization initiators, benzophenone-based photopolymerization initiators, ketal-based photopolymerization initiators, and thioxanthone-based photopolymerization initiators.

Examples of benzoin ether-based photopolymerization initiators include benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2-diphenylethane-1-one, and anisole methyl ether. Examples of acetophenone-based photopolymerization initiators include 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexyl phenyl ketone, 4-phenoxydichloroacetophenone, and 4-(t-butyl)dichloroacetophenone. Examples of α-ketol-based photopolymerization initiators include 2-methyl-2-hydroxypropiophenone and 1-[4-(2-hydroxyethyl)phenyl]-2-methylpropan-1-one. Examples of aromatic sulfonyl chloride-based photopolymerization initiators include 2-naphthalenesulfonyl chloride. Examples of photoactive oxime-based photopolymerization initiators include 1-phenyl-1,1-propanedione-2-(o-ethoxycarbonyl)-oxime. Examples of benzoin-based photopolymerization initiators include benzoin. Examples of benzyl-based photopolymerization initiators include benzil. Examples of benzophenone-based photopolymerization initiators include benzophenone, benzoylbenzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, α-hydroxycyclohexylphenyl ketone. Examples of ketal-based photopolymerization initiators include benzyl dimethyl ketal. Examples of thioxanthone-based photopolymerization initiators include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, and dodecylthioxanthone.

[A-2-1-2. Preferred embodiment 2 of (meth)acrylic resin (1)]
As a preferred embodiment 2 of the (meth)acrylic resin (1), in terms of being able to further exert the effects of the present invention, it is preferably a (meth)acrylic resin (B) formed by polymerization from a composition (B) containing, as a monomer component, a (meth)acrylic acid ester having a cyclic structure in the molecule, and more preferably a (meth)acrylic resin (B) formed by polymerization from a composition (B) containing, as monomer components, a (meth)acrylic acid ester having a cyclic structure in the molecule and a (meth)acrylic acid alkyl ester having a linear or branched alkyl group.

The cyclic structure (ring) of a (meth)acrylic acid ester having a cyclic structure in the molecule (hereinafter sometimes referred to as a "ring-containing (meth)acrylic acid ester") may be either an aromatic ring or a non-aromatic ring. Examples of aromatic rings include aromatic carbon rings (e.g., monocyclic carbon rings such as a benzene ring, and condensed carbon rings such as a naphthalene ring), and various aromatic heterocycles. Examples of non-aromatic rings include non-aromatic aliphatic rings (non-aromatic alicyclic rings) (e.g., cycloalkane rings such as a cyclopentane ring, a cyclohexane ring, a cycloheptane ring, and a cyclooctane ring; cycloalkene rings such as a cyclohexene ring; etc.), non-aromatic bridged rings (e.g., bicyclic hydrocarbon rings such as pinane, pinene, bornane, norbornane, and norbornene; tricyclic or higher aliphatic hydrocarbon rings (bridged hydrocarbon rings) such as adamantane), and non-aromatic heterocycles (e.g., epoxy rings, oxolane rings, oxetane rings, etc.).

Examples of tricyclic or higher aliphatic hydrocarbon rings (tricyclic or higher bridged hydrocarbon rings) include dicyclopentanyl, dicyclopentenyl, adamantyl, tricyclopentanyl, and tricyclopentenyl groups.

That is, examples of ring-containing (meth)acrylic acid esters include (meth)acrylic acid cycloalkyl esters such as cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, cycloheptyl (meth)acrylate, and cyclooctyl (meth)acrylate; (meth)acrylic acid esters having a bicyclic aliphatic hydrocarbon ring such as isobornyl (meth)acrylate; dicyclopentanyl (meth)acrylate, dicyclopentanyloxyethyl (meth)acrylate, tricyclopentanyl (meth)acrylate, 1-adamantyl (meth)acrylate, and the like. Examples of the (meth)acrylic acid esters include (meth)acrylic acid esters having three or more aliphatic hydrocarbon rings, such as 2-methyl-2-adamantyl (meth)acrylate, 2-ethyl-2-adamantyl (meth)acrylate, etc.; (meth)acrylic acid esters having aromatic rings, such as (meth)acrylic acid aryl esters, such as (meth)acrylic acid phenyl, (meth)acrylic acid aryloxyalkyl esters, such as (meth)acrylic acid phenoxyethyl, and (meth)acrylic acid arylalkyl esters, such as (meth)acrylic acid benzyl. Among these, the ring-containing (meth)acrylic acid esters are preferably non-aromatic ring-containing (meth)acrylic acid esters, more preferably cyclohexyl acrylate (CHA), cyclohexyl methacrylate (CHMA), dicyclopentanyl acrylate (DCPA), and dicyclopentanyl methacrylate (DCPMA), and even more preferably acrylate (DCPA) and methacrylate (DCPMA).

The ring-containing (meth)acrylic acid ester may be one type or two or more types.

The content of the ring-containing (meth)acrylic ester is preferably 10% by weight or more, more preferably 20% by weight to 90% by weight, even more preferably 30% by weight to 80% by weight, and particularly preferably 40% by weight to 70% by weight, based on the total amount (100% by weight) of the monomer components constituting the (meth)acrylic resin (B), in order to further exert the effects of the present invention.

Examples of (meth)acrylic acid alkyl esters having a linear or branched alkyl group include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, isopentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and isooctyl (meth)acrylate. , nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate, nonadecyl (meth)acrylate, eicosyl (meth)acrylate, lauryl (meth)acrylate, and other (meth)acrylic acid alkyl esters having an alkyl group of 1 to 20 carbon atoms. Among these, methyl methacrylate (MMA) and lauryl (meth)acrylate are preferred as (meth)acrylic acid alkyl esters having a linear or branched alkyl group.

The (meth)acrylic acid alkyl ester having a linear or branched alkyl group may be one type or two or more types.

The content of the (meth)acrylic acid alkyl ester having a linear or branched alkyl group is preferably 10% by weight or more, more preferably 20% by weight to 90% by weight, even more preferably 25% by weight to 80% by weight, particularly preferably 30% by weight to 70% by weight, and most preferably 30% by weight to 60% by weight, based on the total amount (100% by weight) of the monomer components constituting the (meth)acrylic resin (B), in order to further exert the effects of the present invention.

The composition (B) may contain a copolymerizable monomer other than the ring-containing (meth)acrylic acid ester and the (meth)acrylic acid alkyl ester having a linear or branched alkyl group. The copolymerizable monomer may be one type only, or two or more types. Examples of such copolymerizable monomers include (meth)acrylic acid alkoxyalkyl esters such as 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, 3-methoxypropyl (meth)acrylate, 3-ethoxypropyl (meth)acrylate, 4-methoxybutyl (meth)acrylate, and 4-ethoxybutyl (meth)acrylate; hydroxyl group (hydroxyl group)-containing monomers such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, vinyl alcohol, and allyl alcohol; (meth)acrylamide, N, Amide group-containing monomers such as N-dimethyl(meth)acrylamide, N-methylol(meth)acrylamide, N-methoxymethyl(meth)acrylamide, N-butoxymethyl(meth)acrylamide, and N-hydroxyethyl(meth)acrylamide; amino group-containing monomers such as aminoethyl(meth)acrylate, dimethylaminoethyl(meth)acrylate, and t-butylaminoethyl(meth)acrylate; cyano group-containing monomers such as acrylonitrile and methacrylonitrile; sulfonic acid group-containing monomers such as sodium vinyl sulfonate; phosphoric acid group-containing monomers such as 2-hydroxyethyl acryloyl phosphate; isocyanate group-containing monomers such as 2-methacryloyloxyethyl isocyanate; imide group-containing monomers such as cyclohexylmaleimide and isopropylmaleimide; and the like.

As the copolymerizable monomer, a polyfunctional monomer may also be used. A polyfunctional monomer refers to a monomer having two or more ethylenically unsaturated groups in one molecule. As the ethylenically unsaturated group, any appropriate ethylenically unsaturated group may be used as long as it does not impair the effects of the present invention. Examples of such ethylenically unsaturated groups include radically polymerizable functional groups such as vinyl groups, propenyl groups, isopropenyl groups, vinyl ether groups (vinyloxy groups), and allyl ether groups (allyloxy groups). Examples of polyfunctional monomers include hexanediol di(meth)acrylate, butanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, trimethylolpropane tri(meth)acrylate, tetramethylolmethane tri(meth)acrylate, allyl (meth)acrylate, vinyl (meth)acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, urethane acrylate, etc. Such polyfunctional monomers may be used alone or in combination of two or more kinds.

Composition (B) may contain any appropriate other components as long as the effects of the present invention are not impaired. Examples of such other components include a polymerization initiator, a chain transfer agent, and a solvent. The content of these other components may be any appropriate content as long as the effects of the present invention are not impaired.

The polymerization initiator may be a thermal polymerization initiator or a photopolymerization initiator (photoinitiator), depending on the type of polymerization reaction. There may be only one type of polymerization initiator, or two or more types.

As for the thermal polymerization initiator and photopolymerization initiator (photoinitiator), the explanation in the section [A-2-1-1. Preferred embodiment 1 of (meth)acrylic resin (1)] may be used.

<A-2-2. Urethane-based adhesive (1)>
As the urethane-based adhesive (1), any suitable urethane-based adhesive may be adopted, such as a known urethane-based adhesive described in JP-A-2017-039859, etc., within the scope of the present invention. Such a urethane-based adhesive (1) may be, for example, a urethane-based adhesive formed from a urethane-based adhesive composition, the urethane-based adhesive composition containing at least one selected from the group consisting of urethane prepolymers and polyols, and a crosslinking agent. The urethane-based adhesive (1) may be only one type, or may be two or more types. The urethane-based adhesive (1) may contain any suitable component within the scope of the present invention.

<A-2-3. Rubber-based adhesive (1)>
As the rubber-based adhesive (1), any appropriate rubber-based adhesive may be adopted, for example, a known rubber-based adhesive described in JP-A-2015-074771, etc., within the scope of not impairing the effects of the present invention. The rubber-based adhesive (1) may be only one type, or may be two or more types. The rubber-based adhesive (1) may contain any appropriate component within the scope of not impairing the effects of the present invention.

<A-2-4. Silicone-based adhesive (1)>
As the silicone-based pressure-sensitive adhesive (1), any suitable silicone-based pressure-sensitive adhesive may be adopted, for example, a known silicone-based pressure-sensitive adhesive described in JP-A-2014-047280, etc., within the scope of not impairing the effects of the present invention. The silicone-based pressure-sensitive adhesive (1) may be of only one type, or may be of two or more types. The silicone-based pressure-sensitive adhesive (1) may contain any suitable component within the scope of not impairing the effects of the present invention.

<A-3. Base film (1)>
The thickness of the base film (1) may be any appropriate thickness depending on the purpose, as long as it does not impair the effects of the present invention. In order to more effectively exhibit the effects of the present invention, the thickness is preferably 20 μm to 500 μm, more preferably 20 μm to 300 μm, even more preferably 20 μm to 200 μm, particularly preferably 20 μm to 100 μm, and most preferably 20 μm to 80 μm.

The substrate film (1) includes a resin substrate film (1a).

For the resin substrate film (1a), the explanation for the resin substrate film (IIIa) in section A-1. Release liner (III) may be used.

The substrate film (1) may have a conductive layer (1b). The conductive layer (1b) may be disposed, for example, between the pressure-sensitive adhesive layer (1) and the resin substrate film (1a).

The conductive layer (1b) may be a single layer or may be two or more layers.

The conductive layer (1b) can be provided by forming it on any suitable substrate. Such a substrate is preferably a resin substrate film (1a).

The conductive layer (1b) is formed by forming a conductive layer on any suitable substrate (preferably a resin substrate film (1a)) using any suitable thin film formation method, such as vacuum deposition, sputtering, ion plating, spray pyrolysis, chemical plating, electroplating, or a combination of these. Among these thin film formation methods, vacuum deposition and sputtering are preferred in terms of the rate at which the conductive layer is formed, the ability to form a large-area film, productivity, and the like.

Materials for forming the conductive layer (1b) include, for example, metal-based materials such as gold, silver, platinum, palladium, copper, aluminum, nickel, chromium, titanium, iron, cobalt, tin, and alloys thereof; metal oxide-based materials such as indium oxide, tin oxide, titanium oxide, cadmium oxide, and mixtures thereof; and other metal compounds such as copper iodide.

The thickness of the conductive layer (1b) may be any appropriate thickness depending on the purpose, as long as it does not impair the effects of the present invention. For example, when the conductive layer (1b) is made of a metal material, the thickness is preferably 30 Å to 600 Å, and when the conductive layer (1b) is made of a metal oxide material, the thickness is preferably 80 Å to 5000 Å.

The surface resistance value of the conductive layer (1b) is preferably 1.0×10 ¹⁰ Ω/□ or less, more preferably 1.0×10 ⁹ Ω/□ or less, even more preferably 1.0×10 ⁸ Ω/□ or less, and particularly preferably 1.0×10 ⁷ Ω/□ or less.

When forming the conductive layer on any suitable substrate (preferably a resin substrate film (1a)), the surface of the substrate (preferably a resin substrate film (1a)) may be subjected to any suitable pretreatment such as corona discharge treatment, ultraviolet irradiation treatment, plasma treatment, sputter etching treatment, undercoat treatment, etc., to enhance adhesion between the conductive layer and the substrate (preferably a resin substrate film (1a)).

The substrate film (1) may have an antistatic layer (1c). The antistatic layer (1c) may typically be disposed between the adhesive layer (1) and the resin substrate film (1a) and/or between the resin substrate film (1a) and the adhesive layer (2).

The antistatic layer (1c) may consist of only one layer, or two or more layers.

The thickness of the antistatic layer (1c) may be any appropriate thickness depending on the purpose, as long as it does not impair the effects of the present invention. Such a thickness is preferably 1 nm to 1000 nm, more preferably 5 nm to 900 nm, even more preferably 7.5 nm to 800 nm, and particularly preferably 10 nm to 700 nm.

The surface resistance value of the antistatic layer (1c) is preferably 1.0×10 ¹⁰ Ω/□ or less, more preferably 8.0×10 ⁹ Ω/□ or less, even more preferably 5.0×10 ⁹ Ω/□ or less, and particularly preferably 1.0×10 ⁹ Ω/□ or less.

As the antistatic layer (1c), any suitable antistatic layer may be used as long as it has an antistatic effect and does not impair the effects of the present invention. For such an antistatic layer (1c), the explanation of the antistatic layer (IIIc) in the section A-1. Release liner (III) may be used.

<A-4. Pressure-sensitive adhesive layer (2)>
Any appropriate pressure-sensitive adhesive layer may be adopted as the pressure-sensitive adhesive layer (2) as long as the effects of the present invention are not impaired. The pressure-sensitive adhesive layer (2) may be a single layer or may be two or more layers.

The thickness of the adhesive layer (2) is preferably 0.5 μm to 150 μm, more preferably 1 μm to 100 μm, even more preferably 2 μm to 80 μm, particularly preferably 3 μm to 50 μm, and most preferably 5 μm to 24 μm, in order to better exhibit the effects of the present invention.

The adhesive layer (2) may be formed by any suitable method. For example, an adhesive composition (preferably an acrylic adhesive composition (2)) that forms the adhesive constituting the adhesive layer (2) may be applied to any suitable substrate (for example, substrate film (2)), heated and dried as necessary, and cured as necessary to form an adhesive layer on the substrate. Examples of such application methods include a gravure roll coater, reverse roll coater, kiss roll coater, dip roll coater, bar coater, knife coater, air knife coater, spray coater, comma coater, direct coater, and roll brush coater.

The adhesive layer (2) may contain other components (2). The other components (2) may be one type or two or more types. Any appropriate other components may be used as the other components (2) as long as they do not impair the effects of the present invention. Examples of such other components (1) include other polymer components, crosslinking accelerators, crosslinking catalysts, silane coupling agents, tackifier resins (rosin derivatives, polyterpene resins, petroleum resins, oil-soluble phenols, etc.), anti-aging agents, inorganic fillers, organic fillers, metal powders, colorants (pigments, dyes, etc.), foil-like materials, ultraviolet absorbers, antioxidants, light stabilizers, chain transfer agents, plasticizers, softeners, surfactants, conductive components, stabilizers, surface lubricants, leveling agents, corrosion inhibitors, heat stabilizers, polymerization inhibitors, lubricants, solvents, catalysts, etc.

Representative examples of the other components (2) include conductive components. The conductive components may be of only one type, or may be of two or more types. Any appropriate conductive component may be used as the conductive component as long as it does not impair the effects of the present invention. Examples of such conductive components include ionic liquids, ion-conducting polymers, ion-conducting fillers, and electrically conductive polymers.

<A-4-1. Acrylic adhesive>
The pressure-sensitive adhesive layer (2) is preferably composed of an acrylic pressure-sensitive adhesive (2).

The acrylic adhesive (2) is formed from an acrylic adhesive composition (2).

The acrylic pressure-sensitive adhesive composition (2) preferably contains an acrylic polymer (C) in that the effects of the present invention can be more effectively achieved.

The acrylic polymer (C) is what can be called a base polymer in the field of acrylic pressure sensitive adhesives. The acrylic polymer may be of only one type, or of two or more types.

The content of the acrylic polymer (C) in the acrylic pressure-sensitive adhesive composition (2) is preferably 60% by weight to 99.9% by weight, more preferably 65% by weight to 99.9% by weight, even more preferably 70% by weight to 99.9% by weight, particularly preferably 75% by weight to 99.9% by weight, and most preferably 80% by weight to 99.9% by weight, calculated on a solid content basis.

As the acrylic polymer (C), any suitable acrylic polymer may be used as long as it does not impair the effects of the present invention.

The weight average molecular weight of the acrylic polymer (C) is preferably 300,000 to 2,500,000, more preferably 350,000 to 2,000,000, even more preferably 400,000 to 1,800,000, and particularly preferably 500,000 to 1,500,000, in order to further exert the effects of the present invention.

The acrylic adhesive composition (2) may contain a crosslinking agent. By using a crosslinking agent, the cohesive strength of the acrylic adhesive can be improved, and the effects of the present invention can be more effectively achieved. The crosslinking agent may be one type only, or two or more types.

As for the crosslinking agent, the explanation in the section <A-2-1. Acrylic adhesive (1)> may be used.

The content of the crosslinking agent in the acrylic pressure-sensitive adhesive composition (2) may be any appropriate content within the range that does not impair the effects of the present invention. For example, such a content is preferably 0.05 parts by weight to 20 parts by weight, more preferably 0.1 parts by weight to 18 parts by weight, even more preferably 0.5 parts by weight to 15 parts by weight, and particularly preferably 0.5 parts by weight to 10 parts by weight, relative to the solid content (100 parts by weight) of the acrylic polymer (C), in terms of being able to further exhibit the effects of the present invention.

The acrylic adhesive composition (2) may contain any other appropriate components within the scope of the present invention. Examples of such other components include polymer components other than acrylic polymers, crosslinking accelerators, crosslinking catalysts, silane coupling agents, tackifier resins (rosin derivatives, polyterpene resins, petroleum resins, oil-soluble phenols, etc.), anti-aging agents, inorganic fillers, organic fillers, metal powders, colorants (pigments, dyes, etc.), foil-like materials, UV absorbers, antioxidants, light stabilizers, chain transfer agents, plasticizers, softeners, surfactants, antistatic agents, conductive agents, stabilizers, surface lubricants, leveling agents, corrosion inhibitors, heat stabilizers, polymerization inhibitors, lubricants, solvents, catalysts, etc.

The acrylic polymer (C) is preferably an acrylic polymer (C) formed by polymerization from a composition (C) containing (component a) a (meth)acrylic acid alkyl ester in which the alkyl group in the alkyl ester portion has 4 to 12 carbon atoms, and (component b) at least one selected from the group consisting of a (meth)acrylic acid ester having an OH group and (meth)acrylic acid, in order to more effectively exert the effects of the present invention. (Component a) and (component b) may each independently be one type or two or more types.

Examples of (meth)acrylic acid alkyl esters (component a) in which the alkyl group of the alkyl ester portion has 4 to 12 carbon atoms include n-butyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, and dodecyl (meth)acrylate. Among these, in terms of being able to more effectively exert the effects of the present invention, n-butyl (meth)acrylate and 2-ethylhexyl (meth)acrylate are preferred, and n-butyl acrylate and 2-ethylhexyl acrylate are more preferred.

At least one type (component b) selected from the group consisting of (meth)acrylic acid esters having an OH group and (meth)acrylic acid includes, for example, (meth)acrylic acid esters having an OH group, such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate, and (meth)acrylic acid. Among these, hydroxyethyl (meth)acrylate and (meth)acrylic acid are preferred, and hydroxyethyl acrylate and acrylic acid are more preferred, in terms of being able to more effectively exert the effects of the present invention.

Composition (C) may contain a copolymerizable monomer other than components (a) and (b). The copolymerizable monomer may be one type only, or two or more types. Examples of such copolymerizable monomers include carboxyl group-containing monomers (excluding (meth)acrylic acid) such as itaconic acid, maleic acid, fumaric acid, crotonic acid, isocrotonic acid, and acid anhydrides thereof (e.g., acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride); (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-methylol(meth)acrylamide, N-methoxymethyl(meth)acrylamide, N-butoxymethyl(meth)acrylamide, N-hydroxyethyl(meth)acrylamide, N-butyl ... Amide group-containing monomers such as acrylamide; amino group-containing monomers such as aminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, and t-butylaminoethyl (meth)acrylate; epoxy group-containing monomers such as glycidyl (meth)acrylate and methylglycidyl (meth)acrylate; cyano group-containing monomers such as acrylonitrile and methacrylonitrile; N-vinyl-2-pyrrolidone, (meth)acryloylmorpholine, N-vinylpiperidone, N-vinylpiperazine, N-vinylpyrrole, and N-vinyl isopropyl alcohol. Heterocyclic vinyl monomers such as midazole, vinylpyridine, vinylpyrimidine, and vinyloxazole; sulfonic acid group-containing monomers such as sodium vinyl sulfonate; phosphoric acid group-containing monomers such as 2-hydroxyethyl acryloyl phosphate; imide group-containing monomers such as cyclohexylmaleimide and isopropylmaleimide; isocyanate group-containing monomers such as 2-methacryloyloxyethyl isocyanate; (meth)acrylic acid esters having alicyclic hydrocarbon groups such as cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, and isobornyl (meth)acrylate; (meth)acrylic acid esters having aromatic hydrocarbon groups such as phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, and benzyl (meth)acrylate; vinyl esters such as vinyl acetate and vinyl propionate; aromatic vinyl compounds such as styrene and vinyl toluene; olefins and dienes such as ethylene, butadiene, isoprene, and isobutylene; vinyl ethers such as vinyl alkyl ethers; vinyl chloride; and the like.

As the copolymerizable monomer, a polyfunctional monomer may also be used. A polyfunctional monomer refers to a monomer having two or more ethylenically unsaturated groups in one molecule. As the ethylenically unsaturated group, any appropriate ethylenically unsaturated group may be used as long as it does not impair the effects of the present invention. Examples of such ethylenically unsaturated groups include radically polymerizable functional groups such as vinyl groups, propenyl groups, isopropenyl groups, vinyl ether groups (vinyloxy groups), and allyl ether groups (allyloxy groups). Examples of polyfunctional monomers include hexanediol di(meth)acrylate, butanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, trimethylolpropane tri(meth)acrylate, tetramethylolmethane tri(meth)acrylate, allyl (meth)acrylate, vinyl (meth)acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, urethane acrylate, etc. Such polyfunctional monomers may be used alone or in combination of two or more kinds.

As the copolymerizable monomer, (meth)acrylic acid alkoxyalkyl esters may also be used. Examples of (meth)acrylic acid alkoxyalkyl esters include 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, 3-methoxypropyl (meth)acrylate, 3-ethoxypropyl (meth)acrylate, 4-methoxybutyl (meth)acrylate, and 4-ethoxybutyl (meth)acrylate. Only one type of (meth)acrylic acid alkoxyalkyl ester may be used, or two or more types may be used.

The content of the (meth)acrylic acid alkyl ester (component a) in which the alkyl group in the alkyl ester portion has 4 to 12 carbon atoms is preferably 30% by weight or more, more preferably 50% to 99% by weight, even more preferably 70% to 98% by weight, and particularly preferably 90% to 98% by weight, based on the total amount (100% by weight) of the monomer components constituting the acrylic polymer (C), in order to further exert the effects of the present invention.

The content of at least one selected from the group consisting of (meth)acrylic acid esters having an OH group and (meth)acrylic acid (component b) is preferably 1% by weight or more, more preferably 1 to 30% by weight, even more preferably 2 to 20% by weight, particularly preferably 3 to 10% by weight, and most preferably 3 to 6% by weight, based on the total amount (100% by weight) of the monomer components constituting the acrylic polymer (C), in order to further exert the effects of the present invention.

Composition (C) may contain any appropriate other components as long as the effects of the present invention are not impaired. Examples of such other components include a polymerization initiator, a chain transfer agent, and a solvent. The content of these other components may be any appropriate content as long as the effects of the present invention are not impaired.

The polymerization initiator may be a thermal polymerization initiator or a photopolymerization initiator (photoinitiator), depending on the type of polymerization reaction. There may be only one type of polymerization initiator, or two or more types.

As for the thermal polymerization initiator and photopolymerization initiator (photoinitiator), the explanation in [1-2-1-1. Preferred embodiment of acrylic polymer (1)] may be used.

<A-4-2. Conductive components>
The pressure-sensitive adhesive layer (2) may contain a conductive component. The conductive component may be one type or two or more types. Any suitable conductive component may be used as the conductive component as long as it does not impair the effects of the present invention. Examples of such conductive components include ionic liquids, ion-conductive polymers, ion-conductive fillers, and electrically conductive polymers.

<A-5. Base film (2)>
The thickness of the base film (2) is preferably 10 μm to 300 μm, more preferably 20 μm to 200 μm, even more preferably 30 μm to 150 μm, particularly preferably 35 μm to 100 μm, and most preferably 35 μm to 80 μm, in order to further exert the effects of the present invention.

The substrate film (2) includes a resin substrate film (2a).

For the resin substrate film (2a), the explanation for the resin substrate film (IIIa) in section A-1. Release liner (III) may be used.

The substrate film (2) may have a conductive layer (2b). The conductive layer (2b) may be disposed between the pressure-sensitive adhesive layer (2) and the resin substrate film (2a).

The conductive layer (2b) may be a single layer or may be two or more layers.

For the conductive layer (2b), the explanation for the conductive layer (1b) in section A-3. Base film (1) may be used.

The substrate film (2) may have an antistatic layer (2c). The antistatic layer (2c) may be disposed between the adhesive layer (2) and the resin substrate film (2a) and/or on the opposite side of the adhesive layer (2) of the resin substrate film (2a).

The antistatic layer (2c) may consist of only one layer, or two or more layers.

The thickness of the antistatic layer (2c) may be any appropriate thickness depending on the purpose, as long as it does not impair the effects of the present invention. Such a thickness is preferably 1 nm to 1000 nm, more preferably 5 nm to 900 nm, even more preferably 7.5 nm to 800 nm, and particularly preferably 10 nm to 700 nm.

For the antistatic layer (2c), the explanation for the antistatic layer (1c) in section A-3. Base film (1) may be used.

The antistatic layer (2c) may contain any other appropriate components as long as they do not impair the effects of the present invention.

<<B. Manufacturing method of adhesive tape for optical components>>
The pressure-sensitive adhesive tape for optical members according to the embodiment of the present invention can be produced by any appropriate method as long as the effects of the present invention are not impaired.

As a representative example of the manufacturing method of the adhesive tape for optical components according to the embodiment of the present invention, the adhesive tape for optical components according to the embodiment of the present invention is a laminate having a release liner (III), an adhesive layer (1), a base film (1), an adhesive layer (2), and a base film (2) in this order, with the least number of layers being 3 or more and the most number of layers being 5 or more, the adhesive layer (1) and the base film (1) being components of the adhesive tape for protecting optical components (I), the adhesive layer (2) and the base film (2) being components of the holding tape (II), the outermost surface of the adhesive tape for protecting optical components (I) opposite the adhesive layer (1) and the adhesive layer (2) being directly laminated, the release liner (III) being directly laminated on the exposed surface of the adhesive layer (1), and two or more adhesive tapes for protecting optical components (I) being laminated on one holding tape (II) with gaps therebetween.

In one embodiment of the method for producing an adhesive tape for optical components according to the present invention, a laminate (X) (i.e., a laminate of a release liner (III) and an adhesive tape for protecting an optical component (I)) having a release liner (III), an adhesive layer (1), and a base film (1) in this order and composed of these components, and a holding tape (II) having an adhesive layer (2) and a base film (2) in this order and composed of these components, are produced, and then the surface of the base film (1) of the laminate (X) and the surface of the adhesive layer (2) of the holding tape (II) are attached to each other so that two or more adhesive tapes for protecting an optical component (I) are arranged with gaps between them on one holding tape (II).

The laminate (X) can be produced, for example, by applying an adhesive composition (at least one selected from the group consisting of an acrylic adhesive composition (1), a urethane adhesive composition (1), a rubber adhesive composition (1), and a silicone adhesive composition (1)) that forms the adhesive constituting the adhesive layer (1) onto a substrate film (1), heating and drying as necessary, and curing as necessary to form the adhesive layer (1) on the substrate film (1), and then attaching a release liner (III) (or the release layer (IIIb) if present) to the surface of the adhesive layer (1) opposite the substrate film (1).

For example, the holding tape (II) is prepared by applying an adhesive composition (preferably at least one selected from the group consisting of acrylic adhesives (2) and urethane adhesives (2)) that forms an adhesive constituting the adhesive layer (2) onto a base film (2), heating and drying as necessary, and curing as necessary to form the adhesive layer (2) on the base film (2). Note that, until the laminate (X) and the holding tape (II) are attached, any suitable separator (e.g., a film similar to the release liner (III)) may be attached to protect the exposed surface of the adhesive layer (2).

In the adhesive tape for optical components according to an embodiment of the present invention, at least one of the corners formed on the opposing side surfaces of two adjacent adhesive tapes for protecting optical components (I) separated by a gap is a chamfered portion, and the chamfered portion is preferably at least one selected from a C-surface and an R-surface. Any appropriate method for forming the chamfered portion may be adopted as long as it does not impair the effects of the present invention. For example, methods for forming the chamfered portion of the C-surface and the chamfered portion of the R-surface include cutting with a blade using a press machine, laser cutting, and cutting using an end mill.

C. Method of using adhesive tape for optical components
The pressure-sensitive adhesive tape for optical members according to the embodiment of the present invention may be used in any appropriate manner as long as the effects of the present invention are not impaired. Representative examples of such usage include the following.

(1) First, the release liner (III) is peeled off from the adhesive tape for optical components according to an embodiment of the present invention. At this time, in the adhesive tape for optical components according to an embodiment of the present invention, at least one of the corners formed on the opposing sides of the two adjacent adhesive tapes for protecting optical components (I) with a gap therebetween is a chamfered portion, so that when the release liner (III) is peeled off, two or more adhesive tapes for protecting optical components (I) stacked in a gap-equipped arrangement on one holding tape (II) can be reliably peeled off at the interface between the release liner (III) and the adhesive tape for protecting optical components (I) while being well held by the holding tape (II). This is because at least one of the corners formed on the opposing sides of two adjacent adhesive tapes for protecting optical components (I) separated by a gap is a chamfered portion, so that when the release liner (III) is peeled off, the force that causes the release liner (III) to separate from the adhesive tape for protecting optical components (I) and the force that causes the adhesive tape for protecting optical components (I) to separate from the holding tape (II) can act in an appropriate balance, suppressing the occurrence of conventional peeling abnormalities.

(2) Next, two or more adhesive tapes for protecting optical components are attached to the exposed adhesive layer (1) while being held by one holding tape, while being aligned with the adherend. This results in a laminate in which the adhesive tape for protecting optical components (I) and the holding tape (II) are laminated in this order on the adherend.

(3) Finally, the retaining tape (II) is peeled off from the laminate obtained in (2) above, and the adhesive tape for protecting optical components (I) is attached to the adherend.

The present invention will be specifically explained below with reference to examples, but the present invention is not limited to these examples. The test and evaluation methods in the examples are as follows. Note that "parts" means "parts by weight" unless otherwise specified, and "%" means "% by weight" unless otherwise specified.

<Release liner peeling evaluation>
The release liner peeling evaluation was carried out as follows using the adhesive tape for protecting optical members (1) obtained in Example 1 (including the adhesive tape for protecting optical members (1A) with a release liner, the adhesive tape for protecting optical members (1B) with a release liner, and the holding tape). The evaluation was carried out in the same manner for the other Examples and Comparative Examples.
The adhesive tape for optical members (1) was arranged so that the holding tape side was adsorbed to the suction stage, and one of the corners of the release liner on the corners 2a and 2b side of the adhesive tape for protecting optical members (1B) with a release liner was gripped by a chucking device. A peeling roller was attached to the chucking device, and the peeling roller was fixed to the surface of the release liner. Then, the chucking device was run in the in-plane direction of the suction stage in the diagonal direction of the gripped corner at a speed of 10 mm/min. At that time, the chucking device was run while being raised at an angle of 45 degrees to the plane of the suction stage and an angle of 30 degrees to the vertical direction of the suction stage. That is, the angle between the adhesive tape for optical members (1) and the peeling direction in a plan view was 45 degrees, and the angle between the plane direction and the peeling direction in a side view was 30 degrees. In this way, the release liners were peeled off from the adhesive tapes for protecting optical members (1A) and (1B). If the pressure-sensitive adhesive tapes for protecting optical members (1A and 1B) could be peeled off without following the release liner when peeled off, the peeling result was evaluated as passed. This test was carried out on 10 samples, and the following evaluation was made.
A: 9 or more out of 10 sheets passed peeling. B: 5 or more out of 10 sheets passed peeling. C: Less than 5 out of 10 sheets passed peeling.

<Measurement of Peel Force A>
The sample was cut to a width of 25 mm and a length of 150 mm to prepare an evaluation sample. The sample was peeled at a peel angle of 180 degrees and a pulling speed of 300 mm/min using a universal tensile tester (manufactured by Minebea Co., Ltd., product name: TCM-1kNB) in an atmosphere of a temperature of 23° C. and a humidity of 50% RH, and the peel force A was measured.

<Measurement of Adhesive Strength B>
The sample was cut to a width of 25 mm and a length of 150 mm to prepare an evaluation sample. The surface of the adhesive layer of the evaluation sample was attached to the surface of the base layer described in each Example and Comparative Example by rolling a 2.0 kg roller once in a reciprocating manner in an atmosphere of 23°C temperature and 50% RH. After curing for 30 minutes in an atmosphere of 23°C temperature and 50% RH humidity, the sample was peeled off at a peel angle of 180° and a pulling speed of 300 mm/min using a universal tensile tester (manufactured by Minebea Co., Ltd., product name: TCM-1kNB) to measure the adhesive strength B.

<Measurement of storage modulus G'>
The storage modulus G' corresponds to the portion stored as elastic energy when a material is deformed, and is an index indicating the degree of hardness.
Only the adhesive layer was taken out from the adhesive tape for protecting optical components formed on a release liner as described in each of the Examples and Comparative Examples, laminated to a thickness of approximately 1 mm, and punched out to a diameter of 9 mm to prepare a cylindrical pellet as a measurement sample.
Using a dynamic viscoelasticity measuring device (ARES, manufactured by Rheometrics Corporation), the obtained measurement sample was fixed to a jig of φ8 mm parallel plates, and the storage modulus G′ was calculated. The measurement conditions were as follows.
Measurement: Shear mode Temperature range: -60℃ to 210℃
Heating rate: 5°C/min Frequency: 1Hz

[Production Example 1]
(Preparation of Oligomer A)
Dicyclopentanyl methacrylate (DCPMA): 60 parts by weight and methyl methacrylate (MMA): 40 parts by weight as monomer components, α-thioglycerol: 3.5 parts by weight as a chain transfer agent, and toluene: 100 parts by weight as a polymerization solvent were mixed and stirred at 70 ° C. for 1 hour under a nitrogen atmosphere. Next, 2,2'-azobisisobutyronitrile (AIBN): 0.2 parts by weight was added as a thermal polymerization initiator, and reacted at 70 ° C. for 2 hours, and then heated to 80 ° C. and reacted for 2 hours. Thereafter, the reaction liquid was heated to 130 ° C., and toluene, the chain transfer agent, and unreacted monomers were dried and removed to obtain a solid acrylic oligomer (oligomer A). The weight average molecular weight of oligomer A was 5100, and the glass transition temperature (Tg) was 130 ° C.

[Production Example 2]
(Preparation of Pressure-Sensitive Adhesive Composition (a) for Pressure-Sensitive Adhesive Tape for Protecting Optical Members)
As monomer components for forming a prepolymer, 40 parts by weight of lauryl acrylate (LA), 50 parts by weight of 2-ethylhexyl acrylate (2EHA), 4 parts by weight of 4-hydroxybutyl acrylate (4HBA), and 6 parts by weight of N-vinyl-2-pyrrolidone (NVP) were blended, along with 0.015 parts by weight of "Irgacure 184" manufactured by BASF as a photopolymerization initiator, and polymerization was carried out by irradiation with ultraviolet light to obtain a prepolymer composition (polymerization rate: approximately 10%).
To 100 parts by weight of the above prepolymer composition, 0.07 parts by weight of 1,6-hexanediol diacrylate (HDDA), 3 parts by weight of the oligomer A prepared in Production Example 1, and 0.3 parts by weight of a silane coupling agent ("KBM403" manufactured by Shin-Etsu Chemical Co., Ltd.) were added as post-addition components, and then these were mixed uniformly to obtain a pressure-sensitive adhesive composition (a) for a pressure-sensitive adhesive tape for protecting optical members.

[Production Example 3]
(Preparation of Pressure-Sensitive Adhesive Composition (b) for Pressure-Sensitive Adhesive Tape for Protecting Optical Members)
2-ethylhexyl acrylate (2EHA): 63 parts by weight as monomer components, N-vinyl-2-pyrrolidone (NVP): 15 parts by weight, methyl methacrylate (MMA): 9 parts by weight, 2-hydroxyethyl acrylate (HEA): 13 parts by weight, 2,2'-azobisisobutyronitrile: 0.2 parts by weight as a polymerization initiator, and ethyl acetate: 133 parts by weight as a polymerization solvent were charged into a separable flask and stirred for 1 hour while introducing nitrogen gas. After removing oxygen from the polymerization system in this way, the temperature was raised to 65°C and reacted for 10 hours, and then ethyl acetate was added to obtain a solution of an acrylic polymer with a solid content concentration of 30% by weight.
An isocyanate-based crosslinking agent (product name "Takenate D110N", manufactured by Mitsui Chemicals, Inc.) was added to the obtained acrylic polymer solution in an amount of 1 part by weight in terms of solid content per 100 parts by weight of the solid content of the acrylic polymer, thereby obtaining a pressure-sensitive adhesive composition (b) for a pressure-sensitive adhesive tape for protecting optical members.

[Production Example 4]
(Preparation of Acrylic Polymer for Retention Tape)
A four-neck flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a cooler was charged with 100 parts by weight of 2-ethylhexyl acrylate (manufactured by Nippon Shokubai Co., Ltd.), 4 parts by weight of 2-hydroxyethyl acrylate (manufactured by Toa Gosei Co., Ltd.), 0.2 parts by weight of 2,2'-azobisisobutyronitrile (manufactured by Wako Pure Chemical Industries, Ltd.) as a polymerization initiator, and 156 parts by weight of ethyl acetate. Nitrogen gas was introduced while gently stirring, and the liquid temperature in the flask was kept at around 65°C to carry out a polymerization reaction for 6 hours, preparing a solution (40% by weight) of an acrylic polymer with a weight average molecular weight of 550,000, and an acrylic polymer for a holding tape was obtained.

[Production Example 5]
(Preparation of holding tape)
To the solution of the acrylic polymer for the retention tape produced in Production Example 4, 5 parts by weight of a crosslinking agent, Coronate HX (manufactured by Nippon Polyurethane Industry Co., Ltd.), 0.3 parts by weight of Aqualon HS-10 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), and 0.03 parts by weight of a crosslinking catalyst, Envirizer OL-1 (manufactured by Tokyo Fine Chemical Co., Ltd.), were added in terms of solid content relative to 100 parts by weight of the solid content, diluted with ethyl acetate so that the total solid content was 25% by weight, stirred with a disperser, and applied to a substrate "Lumirror S10" (thickness 38 μm, manufactured by Toray Industries, Inc.) made of polyester resin with a fountain roll so that the thickness after drying was 10 μm, and cured and dried under conditions of a drying temperature of 130 ° C. and a drying time of 30 seconds. In this way, an adhesive layer was produced on the substrate. Next, the silicone-treated surface of a substrate made of a polyester resin having a thickness of 25 μm and one side of which was silicone-treated was attached to the surface of the adhesive layer to obtain a retention tape.

[Example 1]
A 75 μm thick polyethylene terephthalate (PET) film ("Diafoil MRF75" manufactured by Mitsubishi Chemical) having a silicone-based release layer on the surface was used as a substrate (double-release film), and the adhesive composition (a) for the adhesive tape for protecting optical members obtained in Production Example 2 was applied to the substrate to a thickness of 25 μm to form a coating layer. A 75 μm thick PET film ("Diafoil MRE75" manufactured by Mitsubishi Chemical) having one side treated with silicone release was attached as a cover sheet (double-release film). This laminate was irradiated with ultraviolet light from the cover sheet side using a black light adjusted so that the irradiation intensity on the irradiation surface directly under the lamp was 5 mW/cm ² , and photocured to obtain a 25 μm thick adhesive sheet. Thereafter, the light release film was peeled off from the adhesive sheet, and the adhesive layer formed on the release liner was bonded to one side of a 25 μm thick polyimide-based substrate (product name "Upilex 25RN" Ube Industries, Ltd.) prepared as a substrate layer. The resulting structure was passed once through a laminator (0.3 MPa, speed 0.5 m/min) at 80° C., and then aged for one day in an oven at 50° C., the heavy release film was peeled off, and a new release liner (Diafoil MRF-50, Mitsubishi Plastics, Inc.) was bonded again. In this way, an adhesive tape (1) for protecting optical components with a release liner was obtained.
The obtained adhesive tape (1) for protecting an optical element with a release liner was press-cut and processed to obtain an adhesive tape (1A) for protecting an optical element with a release liner measuring 10 cm in the longitudinal direction, 5 cm in the width direction, and with 1a and 1b of four corners chamfered to C0.5 mm (corresponding to adhesive tape (I) 101 for protecting an optical element in Figure 3 ), and an adhesive tape (1B) for protecting an optical element with a release liner measuring 2 cm in the longitudinal direction, 5 cm in the width direction, and with 2a and 2b of four corners chamfered to C0.5 mm (corresponding to adhesive tape (I) 102 for protecting an optical element in Figure 3 ).
Next, as shown in FIG. 3 , the base film side of the adhesive tape for protecting an optical member with a release liner (1A) and the base film side of the adhesive tape for protecting an optical member with a release liner (1B) were arranged and bonded onto the adhesive layer of the holding tape so as to have a gap of 1 mm in length, and so that the chamfered portions 1a and 1b of the adhesive tape for protecting an optical member with a release liner (1A) face the adhesive tape for protecting an optical member with a release liner (1B) and the chamfered portions 2a and 2b of the adhesive tape for protecting an optical member with a release liner (1B) face the opposite side to the adhesive tape for protecting an optical member with a release liner (1A), thereby obtaining an adhesive tape for an optical member (1).
The results are shown in Table 1.

[Example 2]
An adhesive tape for protecting optical members (2) was obtained in the same manner as in Example 1, except that the thickness of the adhesive layer was set to 15 μm and an adhesive tape for protecting optical members (2) having a release liner was obtained.
The results are shown in Table 1.

[Example 3]
The same procedure as in Example 2 was carried out except that the chamfering was set to C0.2 mm, to obtain an adhesive tape for optical members (3).
The results are shown in Table 1.

[Example 4]
The same procedure as in Example 2 was carried out except that the chamfering was set to C0.1 mm, to obtain an adhesive tape for optical members (4).
The results are shown in Table 1.

[Example 5]
A commercially available release liner (Diafoil MRF-38, Mitsubishi Plastics, Inc.) was prepared. The adhesive composition (b) for an adhesive tape for protecting optical members obtained in Production Example 3 was applied to one surface (release surface) of the release liner so that the thickness after drying would be 25 μm, and dried at 130° C. for 3 minutes. In this way, an adhesive layer having a thickness of 25 μm and composed of an adhesive corresponding to the adhesive composition (b) for an adhesive tape for protecting optical members was formed on the release surface of the release liner, and aging was performed at room temperature for 5 days.
A polyimide-based substrate (trade name "Upilex 25RN" Ube Industries, Ltd.) having a thickness of 25 μm was prepared as the substrate layer. The adhesive layer formed on the release liner was bonded to one side of this substrate layer. The obtained structure was passed once through a laminator (0.3 MPa, speed 0.5 m/min) at 80° C., and then aged in an oven at 50° C. for one day to remove the release liner, and a new release liner (Diafoil MRF-50, Mitsubishi Plastics, Inc.) was bonded again. In this way, an optical component protection adhesive tape (5) with a release liner was obtained. The same procedure as in Example 2 was carried out except that an optical component protection adhesive tape (5) with a release liner was used as the optical component protection adhesive tape with a release liner, and an optical component adhesive tape (5) was obtained.
The results are shown in Table 1.

[Example 6]
The same procedure as in Example 2 was carried out except that the chamfering was performed to a radius of 0.5 mm, thereby obtaining an adhesive tape for optical members (6).
The results are shown in Table 1.

[Example 7]
The same procedure as in Example 2 was carried out except that the chamfering was performed to a radius of 0.1 mm, to obtain an adhesive tape for optical members (7).
The results are shown in Table 1.

[Comparative Example 1]
An adhesive tape for optical members (C1) was obtained in the same manner as in Example 2, except that the chamfering was not performed.
The results are shown in Table 1.

[Comparative Example 2]
An adhesive tape for optical components (C2) was obtained in the same manner as in Example 2, except that a 50 μm-thick polyimide-based substrate (product name "UPILEX 50RN" by Ube Industries, Ltd.) was used instead of the 25 μm-thick polyimide film, and chamfering was not performed.
The results are shown in Table 1.

The adhesive tape for optical components according to the embodiment of the present invention can be suitably used for attachment to, for example, foldable or rollable components. Representative examples of foldable or rollable components include OLEDs.

Adhesive tape for optical components 1000
Adhesive tape for protecting optical components (I) 100, 101, 102, 103
Holding tape (II) 200
Pressure-sensitive adhesive layer (1) 11
Base film (1) 12
Pressure-sensitive adhesive layer (2) 21
Base film (2) 22
Release liner (III) 30
Gap L
Corners 1a, 1b, 1c, 1d, 2a, 2b, 2c, 2d
Chamfered section 1Ca, 1Cb
Surface 10
Back 20
Side 40, 50, 60, 70

Claims (6)

An adhesive tape for protecting an optical member (I) having an adhesive layer (1) on one side of a base film (1);
a holding tape (II) directly laminated on the outermost surface of the pressure-sensitive adhesive tape for protecting an optical member (I) on the opposite side to the pressure-sensitive adhesive layer (1);
a release liner (III) laminated directly on an exposed surface of the pressure-sensitive adhesive layer (1) of the pressure-sensitive adhesive tape for protecting optical members (I);
having
Two or more of the pressure-sensitive adhesive tapes for protecting optical components (I) are laminated on one of the holding tapes (II) in a gap-like arrangement,
The thickness of the pressure-sensitive adhesive layer (1) is less than 25 μm,
At least one of the corners formed on the opposing side surfaces of the two adjacent pressure-sensitive adhesive tapes for protecting optical components (I) with the gap therebetween, when viewed from the pressure-sensitive adhesive layer (1) side of the pressure-sensitive adhesive tape for protecting optical components (I), is a chamfered portion.
Adhesive tape for optical components. The adhesive tape for optical components according to claim 1, wherein the chamfered portion is a C surface and the chamfering amount of the chamfered portion is C0.05 mm or more. The adhesive tape for optical components according to claim 1, wherein the chamfered portion is an R surface and the chamfered amount of the chamfered portion is R 0.05 mm or more. The adhesive tape for optical components according to any one of claims 1 to 3, wherein the peeling force A when peeling off the release liner (III) is smaller than the adhesive force B when peeling off the holding tape (II) in an environment of a temperature of 23°C and a humidity of 50% RH. The adhesive tape for optical components according to any one of claims 1 to 4, wherein the adhesive constituting the adhesive layer (1) has a storage modulus G' at 23°C of 5.0 x 105 Pa or less. The two or more optical component protection pressure-sensitive adhesive tapes (I) are laminated in an arrangement having the gap in the longitudinal direction of the one holding tape (II) ,
at least one of the corners formed on both end side surfaces in the longitudinal direction among the two or more side surfaces of the pressure-sensitive adhesive tape for protecting an optical member (I) when viewed from the pressure-sensitive adhesive layer (1) side of the pressure-sensitive adhesive tape for protecting an optical member (I) is a different chamfered portion.
The pressure-sensitive adhesive tape for optical members according to any one of claims 1 to 5.