JP7619772B2 - Optical laminate and peeling method - Google Patents

Description

The present invention relates to an optical laminate and a method for peeling off a surface protection film.

Polarizing plates are widely used as polarized light supplying elements and polarized light detecting elements in display devices such as liquid crystal display devices and organic electroluminescence (EL) display devices. Conventionally, polarizing plates have been used in which a protective film is attached to one or both sides of a polarizer.

To prevent the surface of such polarizing plates from becoming dirty or scratched, they are sometimes marketed with a peelable surface protection film (also called a "protection film") provided on one surface of the polarizing plate, and an adhesive layer and a release film (also called a "separate film") provided on the other surface (see, for example, Patent Document 1, etc.). The surface protection film is peeled off and removed after the polarizing plate is attached to a member such as an image display element, and the release film is peeled off and removed when the polarizing plate is attached to a member such as an image display element of a display device.

JP 2019-191551 A

In the case of relatively small polarizing plates used in smartphones, smartwatches, etc., a peeling tape is attached to one side of the surface protective film, and the surface protective film may be peeled off by grasping and lifting this peeling tape. When the peeling tape is lifted using this peeling method, the peeling tape may peel off from the surface protective film, making it impossible to peel the surface protective film from the polarizing plate.

The present invention aims to provide an optical laminate and a peeling method that can easily peel off a surface protection film.

The present invention provides the following optical laminate and peeling method.
[1] An optical laminate including, in this order, a surface protective film, a polarizing laminate including a polarizing plate having a protective layer on one or both sides of a linear polarizing layer, and a pressure-sensitive adhesive layer,
the surface protective film is provided releasably on the polarizing laminate,
The polarizing laminate has a thickness of 120 μm or less,
The planar view shape of the optical laminate is a quadrangle having at least one notched portion in which one corner of the quadrangle is notched,
the cutout portion has a shape cut out along a cutout line passing through a first cutout starting point P1 and a second cutout starting point P2 set on a first side and a second side constituting a vertex of the corner portion, respectively;
The optical laminate, wherein the first notch starting point P1 and the second notch starting point P2 are each set so that their distances from the apex are 0.1 mm or more and 0.5 mm or less.
[2] The optical laminate according to [1], wherein the quadrangle is a square.
[3] The optical laminate according to [1] or [2], wherein the notch line is a straight line or an arc-shaped curve.
[4] The optical laminate according to any one of [1] to [3], wherein an end face of the cutout portion of the optical laminate is a surface machined with a rotary tool.
[5] The optical laminate according to any one of [1] to [4], wherein the lengths of the four sides of the rectangle are each within the range of 30 mm or more and 100 mm or less.
[6] The cutout portion has at least two portions,
The optical laminate according to any one of [1] to [5], wherein the cutout portions are provided so as to cut out two adjacent corners of the quadrangle.
[7] The optical laminate according to any one of [1] to [6], wherein the polarizing laminate has a retardation layer on one or both sides of the polarizing plate.
[8] The optical laminate according to any one of [1] to [7], further comprising a release film peelable from the pressure-sensitive adhesive layer on the side of the pressure-sensitive adhesive layer opposite to the polarizing laminate side.
[9] A method for peeling off the surface protective film from the optical laminate according to any one of [1] to [8], comprising the steps of:
A step of attaching the optical laminate to an adherend with the pressure-sensitive adhesive layer;
A step of attaching a peeling tape to a surface of the optical laminate on the surface protective film side;
and peeling the surface protective film from the optical laminate attached to the adherend by raising the peeling tape,
The peeling method includes attaching the peeling tape so as to straddle one side of the optical laminate, the end of which has the notch portion in a plan view, in the attaching step.
[10] The optical laminate is the optical laminate according to [6],
The peeling method according to claim 9, wherein the one side to which the peeling tape is attached is a side having the notches at both ends.

The present invention provides an optical laminate that allows the surface protection film to be easily peeled off.

FIG. 1 is a schematic plan view illustrating an example of an optical laminate of the present invention. This is an x-x' cross-sectional view of the optical laminate shown in Figure 1. FIG. 2 is a schematic plan view showing an example of a step of peeling off a surface protective film from the optical laminate of the present invention. FIG. 2 is a schematic plan view showing another example of the optical laminate of the present invention. FIG. 2 is a schematic cross-sectional view showing a further example of the optical laminate of the present invention. FIG. 2 is a schematic cross-sectional view showing a further example of the optical laminate of the present invention. FIG. 2 is a schematic cross-sectional view showing an example of a step of peeling off a surface protective film from the optical laminate of the present invention. FIG. 1 is a schematic perspective view showing an example of a method for producing an optical laminate of the present invention.

Below, preferred embodiments of the optical laminate and peeling method of the present invention will be described with reference to the drawings. All of the drawings below are presented to aid in understanding the present invention, and the size and shape of each component shown in the drawings do not necessarily correspond to the size and shape of the actual component.

(Optical laminate)
Fig. 1 is a schematic plan view showing an example of an optical laminate of the present embodiment. Fig. 1 shows a schematic plan view of the optical laminate as viewed from the surface protective film side. Fig. 2 is a cross-sectional view of the optical laminate shown in Fig. 1 taken along line xx'.

As shown in FIG. 2, the optical laminate 1a of this embodiment includes, in this order, a surface protective film 41, a polarizing laminate 20 including a polarizing plate 21 having a protective layer on one or both sides of a linear polarizing layer, and an adhesive layer 31. The surface protective film 41 is provided so as to be peelable from the polarizing laminate 20. The thickness of the polarizing laminate 20 is 120 μm or less.

As shown in FIG. 1, the planar shape of the optical laminate 1a is a shape in which one corner of a rectangle 15 has one notch 11b cut out. The notch 11b has a shape cut out along a notch line 10eb passing through a first notch start point P1b (first notch start point P1) and a second notch start point P2b (second notch start point P2) set on each of the first side 15a and the second side 15b, which are two sides constituting the apex Pab of the corner of the rectangle 15. The first notch start point P1b and the second notch start point P2b set on each of the first side 15a and the second side 15b are located within a range in which the distance Laa and the distance Lab from the apex Pab are 0.1 mm or more and 0.5 mm or less, respectively.

The planar shape of the notch line 10eb passing through the first notch starting point P1b and the second notch starting point P2b is not particularly limited. The notch line 10eb may be, for example, a straight line as shown in FIG. 1, or may be an arc-shaped curve. When the notch line 10eb is an arc-shaped curve, it is preferable that the notch line 10eb is convex toward the apex Pab of the corner of the rectangle 15. The length of the notch line 10eb may be, for example, 1 mm or less, 0.9 mm or less, 0.8 mm or less, or 0.7 mm or less.

The shape of the notch line 10eb is preferably set as follows. When the notch line 10eb is traced from the first notch start point P1b side toward the second notch start point P2b in the planar view shape of the optical laminate 1a, it is preferable to set the notch line 10eb so that the shortest distance α from the first side 15a where the first notch start point P1b is located becomes continuously larger, or the shortest distance α gradually becomes larger while including a section where the shortest distance α is constant. Also, when the notch line 10eb is traced from the first notch start point P1b side toward the second notch start point P2b in the planar view shape of the optical laminate 1a, it is preferable to set the notch line 10eb so that the shortest distance β from the second side 15b where the second notch start point P2b is located becomes continuously smaller, or the shortest distance β gradually becomes smaller while including a section where the shortest distance β is constant.

The rectangle 15 is a virtual planar shape set to include the sides of the planar shape of the optical laminate 1a. The rectangle 15 is a rectangle having a first side 15a, a second side 15b, a third side 15c, and a fourth side 15d, as shown in FIG. 1, for example. The first side 15a and a part of the second side 15b of the rectangle 15 shown in FIG. 1 respectively constitute the sides 10a and 10b in the planar shape of the optical laminate 1a, and the entire third side 15c and the fourth side 15d of the rectangle 15 respectively constitute the sides 10c and 10d in the planar shape of the optical laminate 1a. In the planar view of the optical laminate 1a, side 10a is the portion of the first side 15a of the rectangle 15 opposite the side from the first notch start point P1b toward the vertex Pab, and side 10b is the portion of the second side 15b of the rectangle 15 opposite the side from the second notch start point P2b toward the vertex Pab.

In this way, the rectangle 15 set for the planar shape of the optical laminate 1a is a rectangle that is formed by extending sides 10a and 10b in the planar shape of the optical laminate 1a and includes the intersection of the extended portions of these two sides as vertex Pab. Note that when setting the rectangle 15 from the planar shape of the optical laminate 1a, the sides that extend from the planar shape of the optical laminate 1a are set so that the area of the rectangle 15 cut out is minimized when it is assumed that the optical laminate 1a is obtained by cutting out the corners of the rectangle 15.

The distance Laa from the apex Pab to the first notch start point P1b and the distance Lab from the apex Pab to the second notch start point P2b are each independently 0.1 mm or more, may be 0.2 mm or more, may be 0.3 mm or more, may be 0.5 mm or less, or may be 0.4 mm or less. The distances Laa and Lab may be the same as each other, or may be different from each other. As described later, when peeling the surface protective film 41 by attaching a peeling tape 35 (FIG. 3) to the side 10a, it is preferable that the distance Laa is greater than the distance Lab. If the distances Laa and Lab are less than 0.1 mm, it tends to be difficult to peel off the surface protective film 41 well. If the distances Laa and Lab are more than 0.5 mm, the effective area when the optical laminate 1a is attached to the image display element of the display device becomes small, and the image display area of the display device tends to become narrow.

Assuming that the notch line connecting the first notch starting point P1b and the second notch starting point P2b is a straight line, and the area in a plan view of the portion cut out from the rectangle 15 is S1, the area Sa in a plan view of the portion cut out from the rectangle 15 by the notch line 10eb that the optical laminate 1a actually has is preferably 0.6 times or more, or may be 0.7 times or more, or may be 0.9 times or more, and is preferably 1.6 times or less, or may be 1.4 times or less, or may be 1.2 times or less.

3 is a schematic plan view showing an example of a process for peeling the surface protective film from the optical laminate of this embodiment. Since the optical laminate 1a has the cutout portion 11b, the surface protective film 41 can be peeled off well using the peeling tape 35 shown in FIG. 3. Details of the peeling method of the surface protective film 41 using the peeling tape 35 will be described later, but the peeling of the surface protective film 41 from the optical laminate 1a can be performed, for example, as follows. First, as shown in FIG. 3, one end of the peeling tape 35 (hereinafter, sometimes referred to as the "attaching end") is attached to the surface of the optical laminate 1a on the surface protective film 41 side so as to straddle the side 10a on which the cutout portion 11b is provided. Next, the end of the peeling tape 35 opposite to the attaching end is raised, and the peeling tape 35 is pulled in the direction from the side 10a toward the side 10c (the direction of the arrow in FIG. 3). This allows the surface protective film 41 to be peeled off from the optical laminate 1a. In the optical laminate 1a, a notch 11b is provided at the end of the side 10a to which the peeling tape 35 is attached. This makes it easier for the surface protection film 41 to be pulled up when the peeling tape 35 is pulled up, compared to when the side 10a does not have the notch 11b. Therefore, in the optical laminate 1a, the peeling tape 35 is prevented from peeling off the surface protection film 41, and the peeling tape 35 can be used to smoothly peel off the surface protection film 41.

Figure 4 is a schematic plan view showing another example of the optical laminate of this embodiment. The optical laminate 1a shown in Figure 1 has one notch 11b, but it may have two notches, or three or four notches, as in the optical laminate 1b shown in Figure 4.

The optical laminate 1b shown in FIG. 4 has a cutout portion 11d in addition to the cutout portion 11b described for the optical laminate 1a shown in FIG. 1. The planar shape of the optical laminate 1b is a shape in which two corners of the rectangle 15 are cut out, as shown in FIG. 4. The cutout portion 11b is as described above. The cutout portion 11d has a shape cut out along a cutout line 10ed passing through a first cutout starting point P1d (first cutout starting point P1) and a second cutout starting point P2d (second cutout starting point P2) set on each of the first side 15a and the fourth side 15d, which are two sides constituting the vertex Pda of the corner of the rectangle 15. The first notch starting point P1d and the second notch starting point P2d set on the first side 15a and the fourth side 15d, respectively, are located within a range in which the distance Lba and the distance Lbd from the apex Pda are 0.1 mm or more and 0.5 mm or less. The distances Lba and Lbd may be the same as each other, or may be different from each other. When peeling the surface protective film 41 by attaching a peeling tape 35 (FIG. 3) to the side 10a, it is preferable that the distance Lba is greater than the distance Lbd. The preferred ranges of the distances Lba and Lbd are the same as those described for the distances Laa and Lab.

The planar shape of the notch line 10ed passing through the first notch starting point P1d and the second notch starting point P2d is not particularly limited. The notch line 10ed may be a straight line or an arc-shaped curve, similar to the notch line 10eb. When the notch line 10ed is an arc-shaped curve, it is preferable that the notch line 10ed is convex toward the apex Pda of the corner of the quadrangle 15. The preferred range of the length of the notch line 10ed may be the same as the range described for the notch line 10eb.

The shape of the notch line 10ed is preferably set as follows. When the notch line 10ed is traced from the first notch start point P1d side toward the second notch start point P2d direction in the planar view shape of the optical laminate 1b, it is preferable to set the notch line 10ed so that the shortest distance from the first side 15a where the first notch start point P1d is located becomes continuously larger, or the shortest distance becomes gradually larger while including a section where the shortest distance is constant. Also, when the notch line 10ed is traced from the first notch start point P1d side toward the second notch start point P2d direction in the planar view shape of the optical laminate 1b, it is preferable to set the notch line 10ed so that the shortest distance from the fourth side 15d where the second notch start point P2d is located becomes continuously smaller, or the shortest distance becomes gradually smaller while including a section where the shortest distance is constant.

The rectangle 15 set for the planar shape of the optical laminate 1b is a virtual planar shape set to include the sides of the planar shape of the optical laminate 1b, similar to the optical laminate 1a described above. The first side 15a, the second side 15b, and a part of the fourth side 15d of the rectangle 15 shown in FIG. 4 respectively constitute the sides 10a, 10b, and 10d in the planar shape of the optical laminate 1b, and the entire third side 15c of the rectangle 15 constitutes the side 10c in the planar shape of the optical laminate 1b. In the planar view shape of the optical laminate 1b, side 10a is the line segment between the first notch start point P1b and the first notch start point P1d of the first side 15a of the rectangle 15, side 10b is the portion of the second side 15b of the rectangle 15 opposite the side from the second notch start point P2b toward the vertex Pab, and side 10d is the portion of the fourth side 15d of the rectangle 15 opposite the side from the second notch start point P2d toward the vertex Pda.

The rectangle 15 includes an intersection formed by extending sides 10a and 10b in the planar shape of the optical laminate 1b as vertex Pab, and an intersection formed by extending sides 10d and 10a as vertex Pda. When setting the rectangle 15 from the planar shape of the optical laminate 1b, the sides extending from the planar shape of the optical laminate 1b are set so that the area of the rectangle 15 is minimized when it is assumed that the optical laminate 1b is obtained by notching the corners of the rectangle 15, as in the case of the optical laminate 1a. The shape of the rectangle set for the optical laminate 1b is set so that the optical laminate 1b is obtained by notching two corners of the rectangle.

Assuming that the notch line connecting the first notch starting point P1d and the second notch starting point P2d is a straight line, and the area in a plan view of the portion cut out from the rectangle 15 is S2, the area Sb in a plan view of the portion cut out from the rectangle 15 by the actual notch line 10ed of the optical laminate 1b is preferably 0.6 times or more, or may be 0.7 times or more, or may be 0.9 times or more, and is preferably 1.6 times or less, or may be 1.4 times or less, or may be 1.2 times or less.

In the optical laminate 1b, a notch 11b and a notch 11d are formed at adjacent corners of the rectangle 15. Therefore, the force required to lift the surface protective film 41 using the peeling tape 35 in the above-described procedure is smaller than when peeling the surface protective film 41 in the optical laminate 1a, and it is believed that the surface protective film 41 is more easily lifted. As a result, in the optical laminate 1b, the surface protective film 41 can be peeled off even more smoothly using the peeling tape 35.

Although the above description has been given with an example of an optical laminate having one or two notches, a rectangle can also be set for the planar shape of an optical laminate having three or four notches in the same manner as above. Note that when an optical laminate has two or more notches, the shape of the rectangle is set so that, assuming that the corners of the rectangle are notched according to the number of notches that the optical laminate has, an optical laminate having the corresponding number of notches is obtained.

When the optical laminate has two or more cutouts, the shapes of the cutouts may be the same or different. When the optical laminate has two or more cutouts, it is preferable that at least two of the cutouts are arranged to cut out two adjacent corners of a rectangle that is set relative to the planar view shape of the optical laminate, such as cutouts 11b and 11d of optical laminate 1b shown in FIG. 4.

As long as the optical laminates 1a and 1b (hereinafter, both may be referred to as "optical laminate 1") have the notch portion described above, they may have a notch shape that is cut out in a shape different from the notch portion. For example, in addition to the notch portion described above, the optical laminate 1 may have a notch shape in which a corner of the rectangle 15 is notched by a line passing through two points that are outside the range of lengths described above for the distances Laa, Lab, Lba, and Lbd.

The end face (end face in the stacking direction) at the cutout portion 11 of the optical laminate 1 is preferably a surface machined by a rotary tool. When the end face is a surface machined by a rotary tool, the end faces of the surface protection film 41 and the polarizing laminate 20 included in the optical laminate 1 are slightly deformed according to the rotation direction of the rotary tool. This deformed state means that the ends of the surface protection film 41 and the polarizing laminate 20 are partially warped or sagging slightly in the stacking direction rather than parallel to the planar direction of the optical laminate 1. The above deformation on the end face of the optical laminate 1a allows the surface protection film 41 to be peeled off more smoothly.

The quadrangle 15 set relative to the planar shape of the optical laminate 1 is preferably a square. In this specification, a square refers to a quadrangle whose four vertices are right angles (with interior angles of 90°), specifically a square or a rectangle. It is more preferable that the quadrangle 15 is a rectangle.

The lengths of the four sides of the rectangle 15 are preferably 30 mm or more, preferably 40 mm or more, may be 50 mm or more, may be 140 mm or more, or may be 150 mm or more. Also, the lengths are preferably 200 mm or less, may be 190 mm or less, may be 180 mm or less, may be 80 mm or less, or may be 70 mm or less.

The surface protective film 41 is a film that can be peeled off from the polarizing laminate 20, and is preferably provided so as to be in direct contact with the polarizing laminate 20. The surface protective film 41 is also called a protective film, and can cover and protect the surface of the polarizing laminate 20 during the manufacturing process of the optical laminate 1a or the manufacturing process of a display device to which the optical laminate 1a is applied, and can prevent the surface from becoming dirty or scratched. The surface protective film 41 can be peeled off and removed, for example, after the optical laminate 1 is attached to an adherend such as an image display element of a display device via the adhesive layer 31.

The polarizing laminate 20 includes a polarizing plate 21 having a protective layer on one or both sides of the linearly polarizing layer. The thickness of the polarizing laminate 20 is 120 μm or less, and may be 110 μm or less, 100 μm or less, 80 μm or less, or 40 μm or less. The thickness of the polarizing laminate 20 is usually 5 μm or more, and may be 10 μm or more, 20 μm or more, 40 μm or more, or 50 μm or more. When edge processing such as polishing is performed in the manufacturing process of the optical laminate 1, the adhesive constituting the adhesive layer 31 may protrude and cover the edge of the optical laminate 1, and this adhesive may reach the edge of the surface protective film 41. In this case, the surface protective film 41 is fixed to the adhesive layer 31 by the adhesive covering the edge of the optical laminate 1, so that it is considered that the surface protective film 41 is difficult to peel off from the optical laminate 1. As the thickness of the polarizing laminate 20 decreases, the distance between the surface protection film 41 and the adhesive layer 31 in the lamination direction of the optical laminate 1 decreases, and it is believed that the surface protection film 41 becomes difficult to peel off due to the adhesive covering the end faces of the optical laminate 1. As described above, the optical laminate 1 has the notches 11b and 11d. Therefore, even if the thickness of the polarizing laminate 20 is small, the surface protection film 41 can be easily peeled off.

The polarizing laminate 20 may be the polarizing plate 21 itself as shown in FIG. 2, or may have an optically functional layer other than the polarizing plate 21. Examples of optically functional layers other than the polarizing plate 21 include a retardation layer, a reflective film, a semi-transmissive reflective film, a brightness enhancing film, an optical compensation film, and a film with an anti-glare function.

Figure 5 is a schematic cross-sectional view showing another example of the optical laminate of this embodiment. The optical laminate shown in Figure 5 shows an example in which the polarizing laminate 20 is a laminate of a polarizing plate 21 and a retardation layer 22. The polarizing plate 21 and the retardation layer 22 can be laminated via a bonding layer such as a pressure-sensitive adhesive layer or an adhesive curing layer. When the polarizing laminate 20 has a retardation layer 22, the retardation layer 22 can be provided on one or both sides of the polarizing plate 21. When the polarizing laminate 20 includes two or more retardation layers 22, one or more retardation layers 22 may be provided on both sides of the polarizing plate 21, or two or more retardation layers 22 may be provided only on one side of the polarizing plate 21. The retardation layer is not particularly limited, and examples thereof include a 1/2 wavelength retardation layer, a 1/4 wavelength retardation layer, a 1/4 wavelength retardation layer with reverse wavelength dispersion, a positive C plate, and the like.

When the retardation layer 22 has a slow axis in the plane, the slow axis may be parallel (0°) to the absorption axis of the polarizing plate, or may have an angle of more than 0°. For example, the slow axis of the retardation layer 22 may have an angle of 15°, 30°, 45°, 60°, 75°, or 90° to the absorption axis of the polarizing plate.

The polarizing laminate 20 may be a circular polarizing plate or an elliptical polarizing plate. In this case, the polarizing laminate 20 may include a polarizing plate 21 and a retardation layer 22. When the polarizing laminate 20 is a circular polarizing plate, the polarizing laminate 20 may have, from the surface protective film 41 side, [i] a polarizing plate 21, a 1/2 wavelength retardation layer, and a 1/4 wavelength retardation layer in this order, [ii] a polarizing plate 21, a 1/4 wavelength retardation layer with reverse wavelength dispersion, and a positive C plate in this order, or [iii] a polarizing plate 21, a positive C plate, and a 1/4 wavelength retardation layer with reverse wavelength dispersion in this order. A bonding layer may be provided between each of the layers [i] to [iii].

The adhesive layer 31 can be used to attach the optical laminate 1 to an adherend such as an image display element of a display device. The adhesive layer 31 is preferably provided so as to be in direct contact with the polarizing laminate 20. When an adhesive layer is used in the polarizing laminate 20 for bonding a polarizing plate and an optical functional layer and/or bonding retardation layers together, the adhesive layer 31 is the adhesive layer located farthest from the surface protection film 41 in the lamination direction of the optical laminate 1.

Figure 6 is a schematic plan view showing another example of the optical laminate of this embodiment. As shown in Figure 6, the optical laminate 1a may further have a release film 32 that can be peeled off from the adhesive layer 31 on the side of the adhesive layer 31 opposite the polarizing laminate 20. The release film 32 is usually provided so as to be in direct contact with the adhesive layer 31. The release film 32 is also called a separate film, and is intended to cover and protect the surface of the adhesive layer 31 so that foreign matter and the like do not adhere to the adhesive layer 31. The release film 32 can be peeled off and removed when the optical laminate 1 is attached to an adherend such as an image display element of a display device by the adhesive layer 31.

The optical laminate 1 can be used in display devices such as smartphones and smartwatches. Examples of display devices include liquid crystal display devices and organic EL (electroluminescence) display devices. The optical laminate 1 is attached to an adherend such as an image display element of a display device by the adhesive layer 31, and then the surface protective film 41 is peeled off. This allows the polarizing laminate 20 contained in the optical laminate 1 to be incorporated into the display device.

(Method for producing optical laminate)
The optical laminate 1 can be manufactured by forming a notch in a raw laminate cut into a predetermined shape and size, the raw laminate having, for example, a surface protective film, a polarizing laminate, a pressure-sensitive adhesive layer, and a release film in this order. Examples of methods for forming a notch in the raw laminate include a method of polishing the end face (end face parallel to the lamination direction) of the raw laminate, and a method of cutting the raw laminate using one or more of a Thomson blade, a laser cutter, etc. in combination. Among these, it is preferable to form a notch by polishing in order to suppress fuzzing and the like generated on the end face in the lamination direction of the optical laminate 1 and obtain good dimensional accuracy of the optical laminate 1. The above-mentioned polishing and cutting may be performed on one raw laminate, or two or more raw laminates may be stacked and performed simultaneously.

The planar shape of the raw material laminate is not particularly limited and may be selected according to the shape of the optical laminate 1. When the cutout portion is formed by polishing, the planar shape of the raw material laminate is preferably a quadrangle 15 (FIGS. 1 and 4) set relative to the planar shape of the optical laminate 1 described above, more preferably a square, and even more preferably a rectangle. By having the planar shape of the raw material laminate be a quadrangle 15 described above, the area of the cutout of the raw material laminate can be reduced.

When manufacturing the optical laminate 1 from a raw laminate having the planar shape of the quadrangle 15 described in Figures 1 and 4, the notches 11b and 11d can be formed by polishing or the like so that the corners of the quadrangle 15 are notched into the shape of a right-angled triangle (e.g., a right-angled isosceles triangle) including the vertices Pab and/or Pda.

8 is a schematic perspective view showing an example of a method for producing the optical laminate of the present embodiment. The method for producing the optical laminate 1 by polishing a raw laminate includes, for example, the following steps:
[a] a first step of stacking a plurality of raw laminates to obtain a laminate W; and [b] a second step of cutting the end surface of the laminate W by moving a rotary tool 60 having a cutting blade and rotating about a rotation axis R relative to the laminate W along a direction parallel to the end surface of the laminate W and perpendicular to the stacking direction.
may include.

In the method for producing the optical laminate 1, for example, after the first step (a) above, polishing is first performed in the second step (b) above on the four sides of the raw laminate having a rectangular shape in plan view, and then polishing is performed in the second step (b) above on the corners of the rectangle to form a notch.

The first step is to stack multiple raw material laminates cut into a predetermined shape to obtain a laminate W. There is no particular limit to the number of raw material laminates contained in the laminate W, but the laminate W may be, for example, a stack of 100 to 500 raw material laminates. The raw material laminate may be, for example, obtained by cutting a long laminate having the layered structure of the raw material laminate.

The second step is a step in which the end face of the laminate W obtained in the first step is cut using a rotary tool 60 to form a machined surface on the end face at the notch of the optical laminate 1, thereby forming the optical laminate 1.

The cutting process in the second step can be performed by an apparatus equipped with a support part 50 and two rotating tools 60, as shown in FIG. 8, for example. The support part 50 presses the laminate W from above and below to fix the laminate W so that it does not move during the cutting process and to prevent the stacked raw material laminates from shifting. The rotating tool 60 is used to cut the end surface of the laminate W, and can rotate around the rotation axis R.

The support unit 50 can include a flat substrate (a means for moving the laminate W) 51; a gate-shaped frame 52 arranged on the substrate 51; a rotary table 53 arranged on the substrate 51 and rotatable about a central axis; and a cylinder 54 arranged opposite the rotary table 53 on the frame 52 and movable up and down. The laminate W is sandwiched and fixed between the rotary table 53 and the cylinder 54 via a jig 55.

The rotary tool 60 has a disk-shaped rotor that rotates around the rotation axis R. The rotor rotates in the direction indicated by the arrow in FIG. 8. On the disk surface of the rotor (the surface facing the end face of the laminate W and parallel to said end face), multiple cutting blades (e.g., 2 to 10, preferably 3 to 7) are arranged at intervals in the rotation direction of the rotor. The rotation axis R is preferably set to pass through the center of the disk surface of the rotor. The cutting blades are provided so as to protrude from the disk surface of the rotor toward the end face of the laminate W, and the rotor rotates around the rotation axis R with the cutting blades in contact with the end face of the laminate W, thereby cutting the end face of the laminate W.

Two rotating tools 60 are provided on both sides of the substrate 51, facing each other. The rotating tools 60 can move in the direction of the rotation axis R according to the size of the laminate W, and the substrate 51 can move so as to pass between the two rotating tools 60. In the cutting process, the laminate W is fixed to the support 50, the position of the rotating tools 60 in the direction of the rotation axis R is appropriately adjusted, and the substrate 51 is moved so that the laminate W passes between the opposing rotating tools 60 while rotating the rotating tools 60 about their rotation axis R. This allows the cutting process to be performed by moving the rotating tool 60 relative to the laminate W in a direction parallel to the end faces of the laminate W and perpendicular to the stacking direction, while abutting the cutting blades of the rotating tool 60 against the exposed end faces facing each other of the laminate W to cut off these end faces.

The relative movement speed between the laminate W and the rotary tool 60 can be selected, for example, from a range of 200 mm/min to 5000 mm/min (more typically, from a range of 500 mm/min to 3000 mm/min). The rotation speed of the rotary tool 60 can be selected, for example, from a range of 2000 rpm to 8000 rpm (more typically, from a range of 2500 rpm to 6000 rpm).

(Method of removing surface protective film)
7 is a schematic cross-sectional view showing an example of a process for peeling the surface protective film from the optical laminate of this embodiment. The peeling method for peeling the surface protective film 41 from the optical laminate 1 includes a process of bonding the optical laminate 1 to an image display element 45 (adherend) with a pressure-sensitive adhesive layer 31 (FIG. 7), a process of attaching a peeling tape 35 to the surface of the optical laminate 1 on the surface protective film 41 side (FIGS. 3 and 7(a)), and a process of peeling the surface protective film 41 from the optical laminate 1 bonded to the image display element 45 by raising the peeling tape 35 (FIGS. 7(b) and 7(c)).

In the step of attaching the peeling tape 35, the peeling tape 35 is attached so as to straddle one side having the notch 11b or the notch 11d at the end in the plan view shape of the optical laminate 1. FIG. 3 shows an example in which the peeling tape 35 is attached so as to straddle the side 10a, but it may be an edge having the notch 11b or 11d at the end (for example, the side 10b shown in FIG. 1 and FIG. 4, the side 10d shown in FIG. 4). As shown in FIG. 4, when the notch 11b and the notch 11d are provided at both ends of the side 10a, it is preferable that the peeling tape 35 is attached so as to straddle the side 10a in order to peel off the surface protective film 41 more effectively by pulling up the peeling tape 35. The peeling tape 35 is usually attached directly to the surface of the surface protective film 41.

When the optical laminate 1 has a release film 32 (FIG. 6), the step of bonding to the image display element 45 is performed after the release film 32 is peeled off from the optical laminate 1. The step of bonding to the image display element 45 may be performed before or after the step of attaching the peeling tape 35.

In the process of peeling off the surface protective film 41, the end of the peeling tape 35 opposite the attachment end, which is the end attached to the surface of the surface protective film 41 side (hereinafter, sometimes referred to as the "gripped end") is grasped, and the peeling tape 35 is pulled in the direction opposite the image display element 45 side (toward the upper right side in FIG. 7(a), the arrow direction in FIG. 7(a)). The gripped end of the peeling tape 35 is folded back toward the attachment end side (arrow direction in FIG. 7(b)) and pulled in the folding direction (arrow direction in FIG. 7(c)), whereby the surface protective film 41 can be peeled off from the optical laminate 1, exposing the surface of the polarizing laminate 20.

The surface protection film 41 may be peeled off manually, but can also be automated using a peeling device. When using a peeling device, the gripping end of the peeling tape 35 is gripped by a chuck of the peeling device, and the chuck and the optical laminate 1 are moved relative to each other to raise the peeling tape 35, thereby peeling off the surface protection film 41.

As described above, by attaching the peeling tape 35 to the side of the optical laminate 1 that has the notch 11b and/or the notch 11d at the end in the planar view, the force required to lift the surface protective film 41 using the peeling tape 35 can be reduced. Therefore, according to the peeling method of this embodiment, the surface protective film can be peeled off better than when the surface protective film is peeled off from an optical laminate that does not have a notch. In particular, when the notch 11b and the notch 11d are provided at both ends of the side 10b as in the optical laminate 1b shown in FIG. 4, the surface protective film 41 can be peeled off even better by attaching the peeling tape 35 to the side 10b.

The following describes in detail each of the components used in the optical laminate and surface protection film peeling method of this embodiment.

(Surface protection film)
The surface protective film is provided on the surface of the polarizing laminate. When the outermost surface of the polarizing laminate is a polarizing plate, the surface protective film is preferably provided on the polarizing plate. The surface protective film may be a resin film for surface protective film having a pressure-sensitive adhesive layer formed thereon, or may be a self-adhesive film formed alone. The thickness of the surface protective film may be, for example, 30 to 200 μm, preferably 30 to 150 μm, and more preferably 30 to 120 μm.

Examples of resins constituting the resin film for surface protection film include polyolefin resins such as polyethylene resins and polypropylene resins; cyclic polyolefin resins; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polycarbonate resins; (meth)acrylic resins, etc. Among these, polyester resins such as polyethylene terephthalate are preferred. The resin film for surface protection film may have a single layer structure, but may also have a multilayer structure of two or more layers. The resin film for surface protection film may be a film that has been subjected to a stretching process such as uniaxial stretching or biaxial stretching.

The adhesion strength (Fp) of the surface protection film to the polarizing laminate 20 at a temperature of 23°C and a relative humidity of 55% is preferably 0.01 N/25 mm or more, may be 0.03 N/25 mm or more, or may be 0.08 N/25 mm or more, and is preferably 0.5 N/25 mm or less, may be 0.4 N/25 mm or less, or may be 0.3 N/25 mm or less.

The adhesion force (Fp) can be measured by the following procedure. The optical laminate 1 is cut into a rectangle of 150 mm x 25 mm and attached to an alkali-free glass substrate (thickness 0.7 mm, Corning Eagle XG) with the adhesive layer 31 to prepare a test specimen. The test specimen is placed in an autoclave with an internal temperature of 50°C and an internal pressure of 490.3 kPa (gauge pressure) for 20 minutes and exposed to a heated and pressurized environment, and then stored in an atmosphere with a temperature of 23°C and a relative humidity of 55% RH for 24 hours to prepare an evaluation sample. The evaluation sample is subjected to a 180° peel test at a moving speed of 300 mm/min using a peeling device (Shimadzu Autograph AGS-50NX) in accordance with JIS K6854-2:1999 "Adhesives - Peel Adhesion Strength Test Method - Part 2: 180° Peel", and the peel force measured is taken as the adhesion force (Fp).

When the surface protection film is a resin film for surface protection film on which an adhesive layer is provided, the thickness of this adhesive layer is preferably 5 μm or more, may be 10 μm or more, or may be 15 μm or more, and is preferably 30 μm or less, may be 25 μm or less, or may be 20 μm or less.

The above-mentioned surface protection film can be obtained by forming an adhesive layer by applying an adhesive to the surface of the resin film for surface protection film, drying, etc. If necessary, the adhesive-coated surface of the resin film for surface protection film may be subjected to a surface treatment (e.g., corona treatment, etc.) to improve adhesion, and a thin layer such as a primer layer (also called an undercoat layer) may be formed. If necessary, when the surface protection film has an adhesive layer, it may have a release layer for covering and protecting the surface of the adhesive layer opposite to the resin film for surface protection film side. This release layer can be peeled off at an appropriate timing when laminating with the polarizing laminate.

A self-adhesive film that can be used as a surface protection film is a film that can adhere by itself without the need for a means for adhesion such as an adhesive layer, and can maintain that adhered state. Self-adhesive films can be formed using, for example, polypropylene-based resins and polyethylene-based resins.

(Polarizing laminate)
The polarizing laminate includes at least a polarizing plate having a protective layer on one or both sides of the linearly polarizing layer. The polarizing laminate may include only a polarizing plate, or may include a polarizing plate and an optical functional layer other than the polarizing plate. Examples of the optical functional layer include those described above. The optical functional layer may be one layer or two or more layers. The linearly polarizing layer and the protective layer, the polarizing plate and the optical functional layer, and the optical functional layers when two or more optical functional layers are laminated may be bonded together via a bonding layer such as a pressure-sensitive adhesive layer or an adhesive curing layer.

(Linear Polarizing Layer)
The linearly polarizing layer has a property of transmitting linearly polarized light having a vibration plane perpendicular to the absorption axis when unpolarized light is incident on the linearly polarizing layer. The linearly polarizing layer may include a polyvinyl alcohol (hereinafter, sometimes abbreviated as "PVA")-based resin film, or may be a cured film obtained by aligning a dichroic dye in a polymerizable liquid crystal compound and polymerizing the polymerizable liquid crystal compound.

Examples of linearly polarizing layers containing a PVA-based resin film include hydrophilic polymer films such as PVA-based films, partially formalized PVA-based films, and partially saponified ethylene-vinyl acetate copolymer films, which have been dyed with iodine or a dichroic substance such as a dichroic dye, and stretched. Because of their excellent optical properties, it is preferable to use a linearly polarizing layer obtained by dyeing a PVA-based resin film with iodine and stretching it uniaxially.

PVA-based resins can be produced by saponifying polyvinyl acetate-based resins. Polyvinyl acetate-based resins can be polyvinyl acetate, which is a homopolymer of vinyl acetate, or a copolymer of vinyl acetate and other monomers that can be copolymerized with vinyl acetate. Examples of other monomers that can be copolymerized with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides with ammonium groups.

The degree of saponification of the PVA-based resin is usually about 85 to 100 mol%, preferably 98 mol% or more. The PVA-based resin may be modified, and for example, polyvinyl formal or polyvinyl acetal modified with aldehydes can be used. The average degree of polymerization of the PVA-based resin is usually about 1,000 to 10,000, preferably about 1,500 to 5,000. The average degree of polymerization of the PVA-based resin can be determined in accordance with JIS K 6726 (1994). If the average degree of polymerization is less than 1,000, it is difficult to obtain favorable polarizing performance, and if it exceeds 10,000, the film processability may be poor.

Other methods for producing a linearly polarizing layer containing a PVA-based resin film include a method including the steps of first preparing a substrate film, applying a solution of a resin such as a PVA-based resin onto the substrate film, and then drying to remove the solvent to form a resin layer on the substrate film. A primer layer can be formed in advance on the surface of the substrate film on which the resin layer is to be formed. As the substrate film, a resin film such as PET or a film using a thermoplastic resin that can be used for the protective layer described below can be used. As a material for the primer layer, a resin obtained by crosslinking a hydrophilic resin used for the linearly polarizing layer can be used.

Next, the amount of solvent such as water in the resin layer is adjusted as necessary, and then the base film and resin layer are uniaxially stretched. The resin layer is then dyed with a dichroic dye such as iodine to adsorb and align the dichroic dye in the resin layer. Next, as necessary, the resin layer with the dichroic dye adsorbed and align is treated with an aqueous boric acid solution, and a washing step is performed to wash off the aqueous boric acid solution. This produces a resin layer with the dichroic dye adsorbed and align, i.e., a film of a linear polarizing layer. Publicly known methods can be used for each step.

The uniaxial stretching of the substrate film and the resin layer may be performed before dyeing, during dyeing, or during the boric acid treatment after dyeing. The uniaxial stretching may be performed at each of these multiple stages. The substrate film and the resin layer may be uniaxially stretched in the MD direction (film conveying direction). In this case, they may be uniaxially stretched between rolls with different peripheral speeds, or may be uniaxially stretched using a heated roll. The substrate film and the resin layer may be uniaxially stretched in the TD direction (direction perpendicular to the film conveying direction). In this case, the so-called tenter method can be used. The substrate film and the resin layer may be stretched by dry stretching in the atmosphere, or by wet stretching in a state in which the resin layer is swollen with a solvent. In order to express the performance of the linearly polarizing layer, the stretching ratio is 4 times or more, preferably 5 times or more, and particularly preferably 5.5 times or more. There is no particular upper limit to the stretching ratio, but from the viewpoint of suppressing breakage, it is preferably 8 times or less.

The linearly polarizing layer produced by the above method can be obtained by laminating a protective layer (described below) and then peeling off the substrate film. This method makes it possible to further reduce the thickness of the linearly polarizing layer.

The thickness of the linearly polarizing layer containing the PVA-based resin film is preferably 1 μm or more, may be 2 μm or more, or may be 5 μm or more, and is preferably 30 μm or less, may be 15 μm or less, or may be 10 μm or less.

As a method for producing a linearly polarizing layer, which is a cured film obtained by orienting a dichroic dye in a polymerizable liquid crystal compound and polymerizing the polymerizable liquid crystal compound, there can be mentioned a method in which a composition for forming a polarizing layer containing a polymerizable liquid crystal compound and a dichroic dye is applied onto a substrate film, and the polymerizable liquid crystal compound is polymerized and cured while maintaining the liquid crystal state to form a linearly polarizing layer. The linearly polarizing layer thus obtained is in a state in which it is laminated onto the substrate film, and the linearly polarizing layer with the substrate film may be used as a polarizing plate, which will be described later. As the substrate film, a resin film such as PET, or a film using a thermoplastic resin that can be used for a protective layer, which will be described later, can be used.

As the dichroic dye, a dye having different absorbance in the long axis direction and absorbance in the short axis direction of the molecule can be used, and for example, a dye having a maximum absorption wavelength (λmax) in the range of 300 to 700 nm is preferable. Examples of such dichroic dyes include acridine dyes, oxazine dyes, cyanine dyes, naphthalene dyes, azo dyes, anthraquinone dyes, etc., and among these, azo dyes are preferable. Examples of azo dyes include monoazo dyes, bisazo dyes, trisazo dyes, tetrakisazo dyes, stilbene azo dyes, etc., and bisazo dyes and trisazo dyes are more preferable.

The composition for forming the polarizing layer may contain a solvent, a polymerization initiator such as a photopolymerization initiator, a photosensitizer, a polymerization inhibitor, and the like. The polymerizable liquid crystal compound, dichroic dye, solvent, polymerization initiator, photosensitizer, polymerization inhibitor, and the like contained in the composition for forming the polarizing layer may be any known compound, and may be, for example, any of those exemplified in JP-A-2017-102479 and JP-A-2017-83843. In addition, the polymerizable liquid crystal compound may be any of the compounds exemplified as the polymerizable liquid crystal compound used to obtain the cured product layer as the retardation layer described later. The method for forming a linear polarizing layer using the composition for forming the polarizing layer may also be the method exemplified in the above publication.

(Polarizing plate)
A linearly polarizing layer can be formed into a polarizing plate by laminating a protective layer on one or both sides of the linearly polarizing layer. This polarizing plate is a so-called linearly polarizing plate. As the protective layer that can be laminated on one or both sides of the linearly polarizing layer, for example, a film formed from a thermoplastic resin excellent in transparency, mechanical strength, thermal stability, moisture blocking property, isotropy, stretchability, etc. is used. Specific examples of such thermoplastic resins include cellulose resins such as triacetyl cellulose; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polyethersulfone resins; polysulfone resins; polycarbonate resins; polyamide resins such as nylon and aromatic polyamide; polyimide resins; polyolefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymers; cyclic polyolefin resins having cyclo- and norbornene structures (also called norbornene-based resins); (meth)acrylic resins; polyarylate resins; polystyrene resins; polyvinyl alcohol resins, and mixtures thereof. When protective layers are laminated on both sides of the linearly polarizing layer, the resin compositions of the two protective layers may be the same or different. In this specification, "(meth)acrylic" means either acrylic or methacrylic. The "(meth)" in (meth)acrylate has the same meaning.

The protective layer may have a retardation characteristic, or may have a functional layer such as a hard coat layer or an anti-reflection layer. The thickness of the protective layer is preferably 3 μm or more, and more preferably 5 μm or more. The thickness of the protective layer is preferably 50 μm or less, and more preferably 30 μm or less. The above upper and lower limit values can be combined in any combination.

(Retardation Layer)
The polarizing laminate may include a retardation layer. The retardation layer may include a layer of a cured product of a polymerizable liquid crystal compound, or may be a stretched resin film.

When the retardation layer includes a cured layer of a polymerizable liquid crystal compound, a rod-shaped polymerizable liquid crystal compound and a disk-shaped polymerizable liquid crystal compound can be used as the polymerizable liquid crystal compound. Either one of these may be used, or a mixture containing both may be used. When the rod-shaped polymerizable liquid crystal compound is aligned horizontally or vertically to the base layer, the optical axis of the polymerizable liquid crystal compound coincides with the long axis direction of the polymerizable liquid crystal compound. When the disk-shaped polymerizable liquid crystal compound is aligned, the optical axis of the polymerizable liquid crystal compound exists in a direction perpendicular to the disk surface of the polymerizable liquid crystal compound. As the rod-shaped polymerizable liquid crystal compound, for example, those described in JP-A-11-513019 (claim 1, etc.) can be suitably used. As the disk-shaped polymerizable liquid crystal compound, those described in JP-A-2007-108732 (paragraphs [0020] to [0067], etc.) and JP-A-2010-244038 (paragraphs [0013] to [0108], etc.) can be suitably used.

In order for the cured layer formed by polymerizing the polymerizable liquid crystal compound to exhibit an in-plane retardation, the polymerizable liquid crystal compound may be aligned in an appropriate direction. When the polymerizable liquid crystal compound is rod-shaped, the in-plane retardation is exhibited by aligning the optical axis of the polymerizable liquid crystal compound horizontally to the plane of the base layer, in which case the optical axis direction and the slow axis direction coincide. When the polymerizable liquid crystal compound is disc-shaped, the in-plane retardation is exhibited by aligning the optical axis of the polymerizable liquid crystal compound horizontally to the plane of the base layer, in which case the optical axis and the slow axis are perpendicular to each other. The alignment state of the polymerizable liquid crystal compound can be adjusted by the combination of the alignment layer and the polymerizable liquid crystal compound.

A polymerizable liquid crystal compound is a compound having at least one polymerizable group and liquid crystal properties. When two or more types of polymerizable liquid crystal compounds are used in combination, it is preferable that at least one type has two or more polymerizable groups in the molecule. The polymerizable group means a group that participates in a polymerization reaction, and is preferably a photopolymerizable group. Here, the photopolymerizable group means a group that can participate in a polymerization reaction by an active radical or acid generated from a photopolymerization initiator described later. Examples of the polymerizable group include a vinyl group, a vinyloxy group, a 1-chlorovinyl group, an isopropenyl group, a 4-vinylphenyl group, an acryloyloxy group, a methacryloyloxy group, an oxiranyl group, an oxetanyl group, a styryl group, and an allyl group. Among them, an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxiranyl group, and an oxetanyl group are preferable, and an acryloyloxy group is more preferable. The liquid crystallinity of the polymerizable liquid crystal compound may be thermotropic or lyotropic liquid crystal, and when thermotropic liquid crystals are classified according to the degree of order, they may be nematic or smectic liquid crystals.

When the retardation layer includes a cured layer of a polymerizable liquid crystal compound, the retardation layer may include an alignment layer. The alignment layer has an alignment regulating force that aligns the polymerizable liquid crystal compound in a desired direction. The alignment layer may be a vertical alignment layer in which the molecular axis of the polymerizable liquid crystal compound is aligned vertically to the substrate layer, a horizontal alignment layer in which the molecular axis of the polymerizable liquid crystal compound is aligned horizontally to the substrate layer, or an inclined alignment layer in which the molecular axis of the polymerizable liquid crystal compound is aligned at an angle to the substrate layer. The first alignment layer and the second alignment layer may be the same alignment layer or different alignment layers.

The alignment layer is preferably solvent-resistant so that it is not dissolved by coating the liquid crystal layer-forming composition, and is heat-resistant to the heat treatment for removing the solvent and for orienting the polymerizable liquid crystal compound. Examples of the alignment layer include an alignment polymer layer formed from an alignment polymer, a photoalignment polymer layer formed from a photoalignment polymer, and a groove alignment layer having a concave-convex pattern or multiple grooves on the layer surface.

The cured layer of the polymerizable liquid crystal compound can be formed by applying a liquid crystal layer-forming composition containing the polymerizable liquid crystal compound onto a substrate layer, drying the composition, and polymerizing the polymerizable liquid crystal compound. The liquid crystal layer-forming composition may be applied onto an alignment layer formed on the substrate layer.

The substrate layer may be a film made of a resin material, for example, a film made of the resin material described above as the thermoplastic resin used to form the protective layer. The thickness of the substrate layer is not particularly limited, but is generally preferably 1 to 300 μm , more preferably 20 to 200 μm, and even more preferably 30 to 120 μm, from the viewpoint of workability such as strength and handling. The substrate layer may be incorporated into the polarizing laminate as a retardation layer together with a cured layer of a polymerizable liquid crystal compound, or the substrate layer may be peeled off, and only the cured layer of the polymerizable liquid crystal compound, or the cured layer and the alignment layer may be incorporated into the polarizing laminate as a retardation layer.

The resin film used for the stretched resin film includes a film made of a thermoplastic resin that can be used to form a protective layer. Examples of stretching treatments include uniaxial stretching and biaxial stretching. The stretching direction in the stretching treatment may be the length direction of the unstretched resin, a direction perpendicular to the length direction, or a direction oblique to the length direction. In the case of uniaxial stretching, the unstretched resin may be stretched in one of these directions. Biaxial stretching may be simultaneous biaxial stretching in which the resin is stretched simultaneously in two of these stretching directions, or sequential biaxial stretching in which the resin is stretched in a predetermined direction and then stretched in the other direction.

The thickness of the retardation layer is preferably 1 μm or more, may be 2 μm or more, or may be 5 μm or more, and is preferably 100 μm or less, may be 50 μm or less, or may be 10 μm or less.

(Laminating layer)
Examples of the lamination layer for laminating each layer included in the polarizing laminate include an adhesive layer or an adhesive cured layer. When the lamination layer is an adhesive layer, it can be formed using an adhesive described in the adhesive layer 31 described later. The adhesive strength of the adhesive layer as the lamination layer to an alkali-free glass substrate (thickness 0.7 mm, Corning "Eagle XG") at a temperature of 23°C and a relative humidity of 55% is preferably 1N/25mm or more, may be 3N/25mm or more, or may be 10N/25mm or more, and is preferably 50N/25mm or less, may be 40N/25mm or less, or may be 30N/25mm or less. The adhesive strength can be measured in accordance with JIS K 6854-2:1999 "Adhesives-Peel Adhesion Strength Test Method-Part 2: 180° Peel". Furthermore, the adhesion to adherends other than the alkali-free glass substrate (thickness 0.7 mm, Corning "Eagle XG") can be considered to be about the same as the adhesion to the general alkali-free glass substrate.

The adhesion force (Fb) between the bonding layer that bonds the layers constituting the polarizing laminate and each layer bonded thereto is usually greater than the adhesion force (Fp) of the surface protection film 41 to the polarizing laminate 20. The difference between the adhesion force (Fb) and the adhesion force (Fp) is, for example, 0.1 N/25 mm or more, preferably 0.5 N/25 mm or more, and usually 50 N/25 mm or less. In addition, the adhesion force (Fa) of the adhesive layer 31 described later to the image display element 45 (adherend) is usually greater than the adhesion force (Fp) of the surface protection film 41 to the polarizing laminate 20, similar to the adhesion force (Fb). The difference between the adhesion force (Fa) and the adhesion force (Fp) is, for example, 1 N/25 mm or more, preferably 3 N/25 mm or more, and usually 50 N/25 mm or less.

If the adhesion force (Fb) is smaller than the adhesion force (Fp), the layers constituting the polarizing laminate 20 may peel off from each other when peeling off the surface protective film 41 after the optical laminate 1 is bonded to the image display element 45 with the adhesive layer 31. Also, if the adhesion force (Fa) is smaller than the adhesion force (Fp), peeling may occur between the adhesive layer 31 and the image display element 45 when peeling off the surface protective film 41 after bonding the optical laminate 1 to the image display element 45 with the adhesive layer 31.

The adhesion force (Fa) may be greater than, less than, or the same as the adhesion force (Fb). When the adhesion force (Fa) is smaller than the adhesion force (Fb), reworking, such as peeling the polarizing laminate 20 bonded to the image display element 45 from the image display element 45 and bonding a new optical laminate 1, can be easily performed.

The storage modulus of the pressure-sensitive adhesive layer as an attachment layer at a temperature of 80° C. is preferably 0.01 MPa or more, may be 0.02 MPa or more, and is preferably 0.3 MPa or less, may be 0.25 MPa or less, or may be 0.2 MPa or less. The storage modulus can be measured under the following conditions using a commercially available viscoelasticity measuring device in accordance with JIS K7244-6, using a pressure-sensitive adhesive layer laminate having a thickness of 0.2 mm, produced by laminating a plurality of pressure-sensitive adhesive layers, punched out into a cylindrical shape having a diameter of 8 mm as a measurement sample.
Normal Force FN: 1N
Distortion γ: 1%
Frequency: 1Hz
Temperature: 80°C

The thickness of the adhesive layer as an attachment layer is preferably 5 μm or more, may be 10 μm or more, or may be 15 μm or more, and is preferably 50 μm or less, may be 25 μm or less, or may be 20 μm or less.

When the lamination layer is an adhesive cured layer, the adhesive cured layer can be formed by curing a curable component in the adhesive composition. The adhesive composition for forming the adhesive cured layer is an adhesive other than a pressure-sensitive adhesive (adhesive), such as a water-based adhesive or an active energy ray curable adhesive.

An example of a water-based adhesive is an adhesive in which a polyvinyl alcohol resin is dissolved or dispersed in water. There are no particular limitations on the drying method when using a water-based adhesive, but for example, a drying method using a hot air dryer or an infrared dryer can be used.

Examples of active energy ray-curable adhesives include solvent-free active energy ray-curable adhesives that contain a curable compound that cures when exposed to active energy rays such as ultraviolet light, visible light, electron beams, and X-rays. By using a solvent-free active energy ray-curable adhesive, it is possible to improve the adhesion between layers.

The active energy ray curable adhesive preferably contains either one or both of a cationic polymerizable curable compound and a radical polymerizable curable compound, since these exhibit good adhesive properties. The active energy ray curable adhesive may further contain a cationic polymerization initiator or a radical polymerization initiator for initiating the curing reaction of the curable compound.

Examples of cationic polymerizable curable compounds include epoxy compounds (compounds having one or more epoxy groups in the molecule), oxetane compounds (compounds having one or more oxetane rings in the molecule), and combinations of these.

Examples of radically polymerizable curable compounds include (meth)acrylic compounds (compounds having one or more (meth)acryloyloxy groups in the molecule), other vinyl compounds having radically polymerizable double bonds, or combinations of these.

The active energy ray-curable adhesive may contain a sensitizer as necessary. The use of a sensitizer improves reactivity, and can further improve the mechanical strength and adhesive strength of the cured adhesive layer. Any known sensitizer can be used as appropriate. When a sensitizer is added, the amount of the sensitizer added is preferably in the range of 0.1 to 20 parts by mass per 100 parts by mass of the total amount of the active energy ray-curable adhesive.

The active energy ray-curable adhesive may contain additives such as ion trapping agents, antioxidants, chain transfer agents, tackifiers, thermoplastic resins, fillers, flow control agents, plasticizers, defoamers, antistatic agents, leveling agents, and solvents, as necessary.

When an active energy ray-curable adhesive is used, the adhesive composition layer can be cured by irradiating it with active energy rays such as ultraviolet rays, visible light, electron beams, or X-rays to form an adhesive layer. As the active energy ray, ultraviolet rays are preferred, and in this case, the light source that can be used may be a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultra-high pressure mercury lamp, a chemical lamp, a black light lamp, a microwave excited mercury lamp, a metal halide lamp, or the like.

(Adhesive Layer)
The pressure-sensitive adhesive layer 31 of the optical laminate is a layer formed using a pressure-sensitive adhesive. In this specification, the "pressure-sensitive adhesive" is a material that exhibits adhesiveness by being attached to an adherend such as an image display element, and is known as a pressure-sensitive adhesive. In addition, the active energy ray-curable pressure-sensitive adhesive described later can adjust the degree of crosslinking and adhesive strength by irradiating with energy rays.

As the adhesive, any adhesive known in the art that has excellent optical transparency can be used without any particular restrictions. For example, an adhesive having a base polymer such as an acrylic, urethane, silicone, or polyvinyl ether adhesive can be used. In addition, an active energy ray curable adhesive, a heat curable adhesive, or the like may be used. Among these, an adhesive having an acrylic resin as a base polymer that has excellent transparency, adhesive strength, removability (hereinafter also referred to as reworkability), weather resistance, heat resistance, and the like is preferable. The adhesive layer is preferably composed of a reaction product of an adhesive composition containing a (meth)acrylic resin, a crosslinking agent, and a silane compound, and may contain other components.

The adhesive layer 31 may be formed using an active energy ray curable adhesive. The active energy ray curable adhesive is prepared by blending an ultraviolet-curable compound such as a multifunctional acrylate into an adhesive composition, forming an adhesive layer, and then curing the adhesive layer by irradiating it with ultraviolet light, thereby forming a harder adhesive layer. The active energy ray curable adhesive has the property of being cured when irradiated with energy rays such as ultraviolet rays or electron beams. The active energy ray curable adhesive has adhesiveness even before irradiation with energy rays, and therefore is an adhesive that has the property of adhering to an adherend such as an image display element and curing when irradiated with energy rays, thereby adjusting the adhesion strength.

Active energy ray-curable adhesives generally contain an acrylic adhesive and an energy ray-polymerizable compound as the main components. Usually, a crosslinking agent is also blended, and if necessary, a photopolymerization initiator, photosensitizer, etc. can also be blended.

It is preferable to use an adhesive layer 31 whose adhesion strength (Fa) to the image display element 45 (adherend) is relatively greater than the adhesion strength (Fp) of the surface protection film to the polarizing laminate described above. It is also preferable to use an adhesive layer 31 whose storage modulus or thickness is relatively greater than the storage modulus or thickness of the adhesive layer as the attachment layer included in the polarizing laminate described above.

The adhesive layer 31 has an adhesion to an alkali-free glass substrate (thickness 0.7 mm, Corning Eagle XG) at a temperature of 23°C and a relative humidity of 55%, and is preferably 5N/25mm or more, may be 8N/25mm or more, or may be 10N/25mm or more, and is preferably 50N/25mm or less, may be 40N/25mm or less, or may be 30N/25mm or less. The adhesive layer 31 has a storage modulus at a temperature of 80°C of preferably 0.01MPa or more, may be 0.02MPa or more, and is preferably 0.3MPa or less, may be 0.25MPa or less, or may be 0.2MPa or less. The adhesive layer 31 can be measured by the method described above for the adhesive layer. The thickness of the adhesive layer 31 is preferably 10 μm or more, may be 15 μm or more, may be 20 μm or more, and is preferably 40 μm or less, may be 35 μm or less, or may be 30 μm or less. In addition, the adhesion to adherends other than the alkali-free glass substrate (thickness 0.7 mm, Corning "Eagle XG") can be considered to be about the same as the adhesion to the general alkali-free glass substrate.

(Release film)
The release film covers and protects the adhesive layer or supports the adhesive layer, and functions as a separator that can be peeled off from the adhesive layer. Examples of the release film include a film in which a release treatment such as silicone treatment has been applied to the surface of the adhesive layer side of the substrate film. Examples of the resin material constituting the substrate film include the same resin material as the above-mentioned resin material constituting the protective layer. The resin film may have a single layer structure, or may be a multilayer resin film having a multilayer structure of two or more layers.

The thickness of the release film can be, for example, 10 μm or more and 200 μm or less, preferably 20 μm or more and 150 μm or less, and more preferably 30 μm or more and 120 μm or less.

The release film may have information about the optical laminate printed or otherwise displayed thereon. Examples of information about the optical laminate include information about the type of polarizing laminate contained in the optical laminate, and information about the direction of the absorption axis of the polarizing plate contained in the polarizing laminate.

(peel tape)
The peeling tape may be an adhesive tape having an adhesive layer formed on one side of a resin film. As the resin film, the resin film exemplified as the resin film for the surface protection film in the surface protection film may be used. The adhesive layer may be formed using the adhesive described in the adhesive layer 31.

(Adherend)
The adherend to which the optical laminate is bonded by the pressure-sensitive adhesive layer 31 is not particularly limited, and may be, for example, an image display element of a display device. The image display element may be selected depending on the type of the display device. Examples of the image display element include display elements such as liquid crystal cells and organic EL display elements.

The present invention will be explained in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[Peeling evaluation]
The release film was peeled off from the optical laminate obtained in the examples and comparative examples, and the optical laminate was attached to a glass plate (holding table) by the exposed adhesive layer to prepare a test sample. A peeling tape (Cellotape (registered trademark) (CT405-AP24), manufactured by Nichiban Co., Ltd.) was attached by sticking it to the surface protective film on the surface of the optical laminate of the test sample. The peeling tape had a width of 24 mm and a length of 100 mm, and was attached to the center position of the short side where the notch was provided in the plan view shape of the optical laminate of the test sample (the center position of the short side when a rectangle without a notch is assumed), straddling the short side, and being disposed on the surface of the surface protective film with a length of 10 mm from one end of the length direction of the peeling tape as the attachment end (see FIG. 3). In the comparative example, the peeling tape was attached to the center position of one short side in the same manner as above.

The gripping end of the peeling tape opposite to the attachment end of the optical laminate was gripped with a chuck of a peeling device (Autograph AGS-50NX, manufactured by Shimadzu Corporation), and a peeling test was performed in which the peeling tape was pulled in a direction toward the other short side opposite to the short side to which the peeling tape was attached, with an angle (peeling angle) relative to the surface direction of the optical laminate of 180° and a peeling speed of 300 mm/min. As a result of the peeling test, a case in which the surface protective film was peeled off from the test sample was evaluated as A, and a case in which the peeling tape was peeled off from the surface protective film and the surface protective film was not peeled off from the test sample was evaluated as B. This peeling test was performed on 10 or 20 test samples, and the peeling failure rate was calculated using the following formula:
Peel failure rate [%] = (number of evaluations B/number of peel tests) x 100
The calculation was based on the following:

Example 1
(Preparation of raw material laminate)
A linearly polarizing layer (thickness 8 μm) in which iodine was adsorbed and aligned on a polyvinyl alcohol-based resin film was prepared. A COP film side (opposite to the HC layer side) of a cyclic olefin-based resin (COP) film (thickness 25 μm) (hereinafter sometimes referred to as "25HC-COP film") having a hard coat (HC) layer formed as a protective layer was attached to one surface of the linearly polarizing layer via a water-based adhesive. An acrylic adhesive layer side of a surface protective film (thickness 53 μm) having an acrylic adhesive layer (thickness 15 μm) formed on a polyester-based resin film (thickness 38 μm) was attached to the HC layer of the protective layer. A triacetyl cellulose (TAC) film (thickness 20 μm) was attached to the other surface of the linearly polarizing layer via a water-based adhesive. As a result, a polarizing plate (1) with a surface protective film was obtained. The polarizing plate with a surface protective film (1) was formed by laminating a surface protective film (polyester-based resin film, acrylic pressure-sensitive adhesive layer), a 25HC-COP film (HC layer, COP film), a linear polarizing layer, and a TAC film in this order.

Next, a retardation layer was prepared in which a λ/4 plate (thickness 2 μm) which is a cured layer of a polymerizable liquid crystal compound, an adhesive cured layer (thickness 2 μm) of an ultraviolet curable adhesive, and a positive C plate (thickness 3 μm) which is a cured layer of a polymerizable liquid crystal compound were laminated in this order. The TAC film of the polarizing plate (1) with a surface protective film and the λ/4 plate of the retardation layer were bonded with a bonding layer (thickness 17 μm) which is an adhesive layer. Next, a release film-attached adhesive layer (1) was prepared in which an adhesive layer (thickness 25 μm) formed using an acrylic adhesive was formed on a release film (thickness 38 μm). The adhesive layer of the release film-attached adhesive layer (1) was attached to the positive C plate side of the retardation layer attached to the polarizing plate (1) with a surface protective film, and the adhesive layer was cut into a rectangle with a long side length of 37 mm and a short side length of 35 mm to obtain a raw material laminate (1). The raw laminate (1) was a laminate of a polarizing plate (1) with a surface protective film (surface protective film, 25HC-COP film, linear polarizing layer, and TAC film), an adhesive layer, a retardation layer (lambda/4 plate, adhesive layer, positive C plate), and an adhesive layer (1) with a release film (adhesive layer, release film) laminated in this order. The thickness of the laminated portion of the raw laminate (1) from the polarizing plate (25HC-COP film, linear polarizing layer, TAC film) to the retardation layer (lambda/4 plate, adhesive layer, positive C plate) was 77 μm. In addition, the direction of the long side of the raw laminate (1) was parallel to the absorption axis of the linear polarizing layer.

(Preparation of optical laminate)
Using the apparatus shown in FIG. 8, a laminate W was prepared by laminating raw material laminates according to the procedure of the first step (above [a]) described above, and the end faces corresponding to the four sides of the raw material laminate were polished according to the procedure of the second step (above [b]) described above. Furthermore, according to the procedure of the second step (above [b]) described above, one corner at one end of one short side of the raw material laminate was polished to obtain an optical laminate having one notch. The polishing of the corner was performed by setting the first notch start point P1 and the second notch start point P2 at positions 0.3 mm (distances Laa and Lab in FIG. 1) in the short side direction and the long side direction from the apex of the corner of the raw material laminate after polishing the end faces corresponding to the four sides (see the first notch start point P1b and the second notch start point P2b in FIG. 1), and was performed along a straight notch line connecting the first notch start point P1 and the second notch start point P2. In each of the above polishing operations, the relative movement speed between the laminate W and the rotary tool 60 was 2100 mm/min, and the rotation speed of the rotary tool was 5400 rpm. The optical laminate thus obtained was subjected to a peeling evaluation. The results are shown in Table 1.

The adhesion between the surface protective film and the peeling tape was measured by the following procedure. The release film was peeled off from the optical laminate obtained above to expose the adhesive layer, and the optical laminate from which the release film had been removed was attached to a glass plate (holding table) using the exposed adhesive layer to prepare a test sample. The peeling tape described in the peeling evaluation section above was attached to the surface of the surface protective film of this test sample, and the adhesion between the surface protective film and the peeling tape was measured by a 180° peeling test (peel angle 180°, peeling speed 300 mm/min) using the peeling device described in the peeling evaluation section above. This adhesion was 9 N/25 mm. Note that when the peeling tape was peeled off, the surface protective film did not peel off from the polarizing laminate.

The adhesion between the acrylic adhesive layer side of the surface protection film and the HC layer side of the 25HC-COP film was measured by a 180° peel test (peel angle 180°, peel speed 300 mm/min) using the peeling device described in the peel evaluation section above, and was found to be 0.03 N/25 mm.

Example 2
An optical laminate was obtained in the same manner as in Example 1, except that two corners at both ends of one short side of the raw laminate (1) were polished to form two notches. As in Example 1, the distances from the vertices of the corners of the raw laminate (1) after polishing the end faces corresponding to the four sides to the first notch start point P1 and the second notch start point P2 of each of the two notches were 0.3 mm, and the notch lines connecting the first notch start point P1 and the second notch start point P2 were both straight lines. A peeling evaluation was performed on the optical laminate. The results are shown in Table 1.

Example 3
An optical laminate was obtained in the same manner as in Example 2, except that the distances from the vertices of the corners of the raw material laminate (the raw material laminate after grinding the end faces corresponding to the four sides) to the first notch starting point P1 and the second notch starting point P2 were each set to 0.2 mm. Peel evaluation was performed on the optical laminate. The results are shown in Table 1.

Example 4
An optical laminate was obtained in the same manner as in Example 2, except that the distances from the vertices of the corners of the raw material laminate (the raw material laminate after grinding the end faces corresponding to the four sides) to the first notch starting point P1 and the second notch starting point P2 were each set to 0.1 mm. Peel evaluation was performed on the optical laminate. The results are shown in Table 1.

Example 5
(Preparation of raw material laminate)
A COP film having a thickness of 16 μm (hereinafter, sometimes referred to as a “16HC-COP film”) on which a hard coat (HC) layer was formed as a protective layer was used, and a polarizing plate with a surface protective film (2) was obtained in the same manner as in Example 1, except that a TAC film was not attached as a protective layer. The polarizing plate with a surface protective film (2) was a film in which a surface protective film (polyester-based resin film, acrylic pressure-sensitive adhesive layer), a 16HC-COP film (HC layer, COP film), and a linear polarizing layer were laminated in this order.

An adhesive layer (2) with a release film was prepared by forming an adhesive layer (thickness 10 μm) using an acrylic adhesive on a release film (thickness 38 μm). A polarizing plate (2) with a surface protective film was used instead of the polarizing plate (1) with a surface protective film, the linear polarizing layer side of the polarizing plate (2) with a surface protective film and the λ/4 plate of the retardation layer were bonded with an adhesive layer (thickness 5 μm), and the adhesive layer of the adhesive layer (2) with a release film was bonded to the positive C plate side of the retardation layer instead of the adhesive layer (1) with a release film. A raw material laminate (2) was obtained in the same manner as in Example 1.

The raw laminate (2) was a laminate of a polarizing plate (2) with a surface protective film (surface protective film, 16HC-COP film, linear polarizing layer), an adhesive layer, a retardation layer (λ/4 plate, adhesive layer, positive C plate), and an adhesive layer (2) with a release film (adhesive layer, release film) laminated in this order. The thickness of the laminated portion from the polarizing plate (16HC-COP film, linear polarizing layer) to the retardation layer (λ/4 plate, adhesive layer, positive C plate) in the raw laminate (2) was 36 μm. In addition, the direction of the long side of the raw laminate (2) was parallel to the absorption axis of the linear polarizing layer.

(Preparation of optical laminate)
An optical laminate was obtained in the same manner as in Example 2, except that the raw laminate (2) was used, the relative movement speed between the laminate W and the rotating tool 60 was 700 mm/min, and the rotation speed of the rotating tool 60 was 4800 rpm. In the same manner as in Example 1, the adhesion between the surface protective film and the peeling tape, and the adhesion between the acrylic pressure-sensitive adhesive layer side of the surface protective film and the HC layer side of the 16HC-COP film were measured, and were found to be 9 N/25 mm and 0.03 N/25 mm, respectively.

Example 6
An optical laminate was obtained in the same manner as in Example 5, except that only one corner at one end of one short side of the raw laminate (2) was polished to form one notch. Peel evaluation was performed on the optical laminate. The results are shown in Table 1.

Comparative Example 1
An optical laminate was obtained in the same manner as in Example 1, except that the corners of the raw material laminate were not polished and no notches were formed. The optical laminate was subjected to a peeling evaluation. The results are shown in Table 1.

Comparative Example 2
An optical laminate was obtained in the same manner as in Example 5, except that the corners of the raw material laminate were not polished and no notches were formed. The optical laminate was subjected to a peeling evaluation. The results are shown in Table 1.

In each of the examples and comparative examples, during the peel test, no peeling was observed between the layers constituting the optical laminate (25HC-COP film or 16HC-COP film, linear polarizing layer, TAC film, adhesive layer, λ/4 plate, lamination layer, positive C plate, adhesive layer) and the glass plate (holding stand).

1, 1a, 1b Optical laminate, 10a, 10b, 10c, 10d Side, 10eb, 10ed Line, 11b, 11d Notch, 15 Rectangle, 15a First side, 15b Second side, 15c Third side, 15d Fourth side, 20 Polarizing laminate, 21 Polarizing plate, 22 Retardation layer, 31 Adhesive layer, 32 Release film, 35 Release tape, 41 Surface protection film, 50 Support, 51 Substrate, 52 Frame, 53 Rotating table, 54 Cylinder, 55 Jig, 60 Rotating tool, Laa, Lab, Lba, Lbd Distance, Pab, Pda Vertex, P1b, P1d (P1) First notch start point, P2b, P2d (P2) Second notch starting point, W laminate.

Claims (10)

An optical laminate comprising, in this order, a surface protective film, a polarizing laminate including a polarizing plate having a protective layer on one or both sides of a linear polarizing layer, and a pressure-sensitive adhesive layer,
the surface protective film is provided releasably on the polarizing laminate,
The polarizing laminate has a retardation layer on one or both sides of the polarizing plate,
The retardation layer includes a cured layer of a polymerizable liquid crystal compound,
The polarizing laminate has a thickness of 100 μm or less,
The planar view shape of the optical laminate is a quadrangle having at least one notched portion in which one corner of the quadrangle is notched,
the cutout portion has a shape cut out along a cutout line passing through a first cutout starting point P1 and a second cutout starting point P2 set on a first side and a second side constituting a vertex of the corner portion, respectively;
the first notch start point P1 and the second notch start point P2 are set such that their distances from the apex are 0.1 mm or more and 0.4 mm or less,
An optical laminate, wherein an end surface of the cutout portion of the optical laminate is a surface machined by a rotating tool . The optical laminate of claim 1, wherein the quadrangle is a square. The optical laminate according to claim 1 or 2, wherein the notch line is a straight line or an arc-shaped curve. The optical laminate according to any one of claims 1 to 3, wherein the polarizing laminate is a circular polarizing plate or an elliptically polarizing plate . The optical laminate according to any one of claims 1 to 4, wherein the length of each of the four sides of the rectangle is within the range of 30 mm to 100 mm. The cutout portion includes at least two cutout portions.
6. The optical laminate according to claim 1, wherein the cutout portions are provided so as to cut out two adjacent corners of the quadrangle. The optical laminate according to any one of claims 1 to 6, wherein the thickness of the polarizing laminate is 80 μm or less. The optical laminate according to any one of claims 1 to 7, further comprising a release film that is peelable from the adhesive layer on the side of the adhesive layer opposite the polarizing laminate side. A method for peeling the surface protective film from the optical laminate according to any one of claims 1 to 8, comprising the steps of:
A step of attaching the optical laminate to an adherend with the pressure-sensitive adhesive layer;
A step of attaching a peeling tape to a surface of the optical laminate on the surface protective film side;
and peeling the surface protective film from the optical laminate attached to the adherend by raising the peeling tape,
The peeling method includes attaching the peeling tape so as to straddle one side of the optical laminate, the end of which has the notch portion in a plan view, in the attaching step. The optical laminate is the optical laminate according to claim 6,
The peeling method according to claim 9 , wherein the one side to which the peeling tape is attached is a side having the notches provided at both ends.

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