WO2021205727A1

WO2021205727A1 - Optical laminate and peeling method

Info

Publication number: WO2021205727A1
Application number: PCT/JP2021/003881
Authority: WO
Inventors: 瑛高月; 白石　貴志; 松本　大輔
Original assignee: 住友化学株式会社
Priority date: 2020-04-09
Filing date: 2021-02-03
Publication date: 2021-10-14
Also published as: CN115362393A; KR20220160692A; TW202138192A

Abstract

[Problem] To provide an optical laminate capable of favorably peeling a surface protective film and a peeling method. [Solution] The optical laminate sequentially comprises: a surface protective film; a polarizing laminate including a polarizing plate having a protective layer on one or both surfaces of a linearly polarizing layer; and an adhesive layer. The surface protective film is provided to be peelable with respect to the polarizing laminate, and the thickness of the polarizing laminate is 120 μm or less. The planar view shape of the optical laminate is a shape having at least one notched part in which one corner portion of a quadrangular shape is notched, and the notched part has a shape notched along a notch line passing through a first notch start point P1 and a second notch start point P2 respectively set on a first side and a second side constituting an apex of the corner portion. The first notch start point P1 and the second notch start point P2 are set so that the distances from the apex are 0.1 mm or more and 0.5 mm or less.

Description

Optical laminate and peeling method

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

The polarizing plate is widely used as a polarization supply element in a display device such as a liquid crystal display device or an organic electroluminescence (EL) display device, and as a polarization detection element. Conventionally, a polarizing plate having a protective film adhered to one side or both sides of a polarizing element has been used.

In such a polarizing plate, in order to suppress stains and scratches on the surface thereof, a surface protective film (also referred to as “protective film”) that can be peeled off from one surface of the polarizing plate is provided on the other surface. A pressure-sensitive adhesive layer and a release film (also referred to as "separate film") may be provided and distributed on the market (for example, Patent Document 1 and the like). The surface protective film is peeled off and removed after attaching a polarizing plate to a member such as an image display element, for example, and the peeling film is peeled off when the polarizing plate is attached to a member such as an image display element of a display device, for example. And removed.

Japanese Unexamined Patent Publication No. 2019-191551

For relatively small polarizing plates used in smartphones, smart watches, etc., the surface protective film may be peeled off by attaching a peeling tape to one side of the surface protective film and holding the peeling tape to cause it. When the peeling tape is caused by such a peeling method, the peeling tape may be peeled from the surface protective film, and the surface protective film may not be peeled from the polarizing plate.

An object of the present invention is to provide an optical laminate and a peeling method capable of satisfactorily peeling a surface protective film.

The present invention provides the following optical laminate and peeling method.
[1] An optical laminate including a surface protective film, a polarizing laminate containing a polarizing plate having a protective layer on one or both sides of a linear polarizing layer, and an adhesive layer in this order.
The surface protective film is provided so as to be peelable from the polarizing laminate.
The thickness of the polarizing laminate is 120 μm or less, and the thickness is 120 μm or less.
The plan view shape of the optical laminate is a shape in which one corner portion of the quadrangle has at least one notched portion.
The notch portion is along a notch line passing through a first notch start point P1 and a second notch start point P2 set on the first side and the second side forming the apex of the corner portion, respectively. Has a notched shape,
An optical laminate in which the first notch start point P1 and the second notch start point P2 are set so that the distances from the vertices are 0.1 mm or more and 0.5 mm or less, respectively.
[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 arcuate curve.
[4] The optical laminate according to any one of [1] to [3], wherein the end surface of the optical laminate in the notch is a surface cut by a rotary tool.
[5] The optical laminate according to any one of [1] to [4], wherein the lengths of the four sides of the quadrangle are each within a range of 30 mm or more and 100 mm or less.
[6] Having at least two notches,
The optical laminate according to any one of [1] to [5], wherein the cutout portion is provided so as to cut out two adjacent corner portions 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 side or both sides of the polarizing plate.
[8] The optical according to any one of [1] to [7], further comprising a release film that can be peeled off from the pressure-sensitive adhesive layer on the side of the pressure-sensitive adhesive layer opposite to the side of the polarizing laminate. Laminated body.
[9] A peeling method for peeling the surface protective film from the optical laminate according to any one of [1] to [8].
The step of adhering the optical laminate to the adherend by the pressure-sensitive adhesive layer, and
A step of attaching a peeling tape to the surface of the optical laminate on the surface protective film side,
A step of peeling the surface protective film from the optical laminate attached to the adherend by causing the peeling tape is included.
The attachment step is a peeling method in which the peeling tape is attached so as to straddle one side provided with the notch at the end in the plan view shape of the optical laminate.
[10] The optical laminate is the optical laminate according to [6].
The peeling method according to [9], wherein the one side on which the peeling tape is attached is a side provided with the notches at both ends.

According to the present invention, it is possible to provide an optical laminate capable of satisfactorily peeling off the surface protective film.

It is a schematic plan view which shows typically an example of the optical laminated body of this invention. FIG. 5 is a cross-sectional view taken along the line xx'of the optical laminate shown in FIG. It is a schematic plan view which shows typically an example of the step of peeling a surface protection film from an optical laminate of this invention. It is a schematic plan view which shows another example of the optical laminated body of this invention schematically. It is schematic cross-sectional view which shows still another example of the optical laminated body of this invention schematically. It is schematic cross-sectional view which shows still another example of the optical laminated body of this invention schematically. It is schematic cross-sectional view which shows typically an example of the step of peeling a surface protection film from an optical laminate of this invention. It is a schematic perspective view which shows typically an example of the manufacturing method of the optical laminated body of this invention.

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

(Optical laminate)
FIG. 1 is a schematic plan view schematically showing an example of the 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 taken along the line xx'of the optical laminate shown in FIG.

As shown in FIG. 2, the optical laminate 1a of the present embodiment includes a surface protective film 41, a polarizing laminate 20, and an adhesive layer 31 in this order. The polarizing laminate 20 includes a polarizing plate 21. This polarizing plate is provided with a protective layer on one side or both sides of the linearly polarizing layer. 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 plan view shape of the optical laminate 1a is a shape having one notched portion 11b in which one corner portion of the quadrangle 15 is notched. The notch portion 11b is a first notch start point P1b (first notch) set on each of the first side 15a and the second side 15b, which are two sides constituting the apex Pab of the corner portion of the quadrangle 15. It has a notched shape along a notch line 10eb passing through a start point P1) and a second notch start point P2b (second notch start point P2). The first notch start point P1b and the second notch start point P2b set on the first side 15a and the second side 15b have a distance Laa and a distance Lab from the apex Pab of 0.1 mm or more and 0.5 mm, respectively. It is located within the following range.

The plan-view shape of the notch line 10eb passing through the first notch start point P1b and the second notch start point P2b is not particularly limited. The notch line 10eb may be, for example, a straight line or an arcuate curve as shown in FIG. When the notch line 10eb is an arcuate curve, it is preferable that the notch line 10eb is convex toward the apex Pab at the corner of the quadrangle 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. In the plan view shape of the optical laminate 1a, when the notch line 10eb is traced from the first notch start point P1b side toward the second notch start point P2b, the first notch start point P1b is located. It is preferable to set the notch line 10eb so that the shortest distance α from one side 15a increases continuously, or gradually increases while including a section in which the shortest distance α is constant. Further, when the notch line 10eb is traced from the first notch start point P1b side toward the second notch start point P2b in the plan view shape of the optical laminate 1a, the second notch start point P2b is positioned. It is preferable to set the notch line 10eb so that the shortest distance β from the second side 15b is continuously reduced, or is gradually reduced while including a section in which the shortest distance β is constant.

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

As described above, the quadrangle 15 set for the plan view shape of the optical laminate 1a extends the

sides

10a and 10b in the plan view shape of the optical laminate 1a, and the intersection of the extended portions of the two sides is the apex. It is a quadrangle included as a pub. When setting the quadrangle 15 from the plan view shape of the optical laminate 1a, it is assumed that the side extending from the plan view shape of the optical laminate 1a is obtained by cutting out the corner portion of the quadrangle 15 to obtain the optical laminate 1a. In this case, the area for cutting out the quadrangle 15 is set to be the minimum.

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 independently 0.1 mm or more and 0.2 mm or more. It may be 0.3 mm or more, 0.5 mm or less, and 0.4 mm or less. The distance Laa and the distance Lab may be the same as each other or different from each other. As will be described later, when the peeling tape 35 (FIG. 3) is attached to the side 10a to peel off the surface protective film 41, it is preferable that the distance Laa is larger than the distance Lab. If the distance Laa and the distance Lab are less than 0.1 mm, it tends to be difficult to perform good peeling of the surface protective film 41. When the distance Laa and the distance Lab exceed 0.5 mm, the effective area when the optical laminate 1a is attached to the image display element of the display device tends to be small, and the image display area in the display device tends to be narrow.

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

FIG. 3 is a schematic plan view schematically showing an example of a step of peeling the surface protective film from the optical laminate of the present embodiment. Since the optical laminate 1a has a notch portion 11b, the surface protective film 41 can be satisfactorily peeled off using the peeling tape 35 shown in FIG. The details of the method of peeling the surface protective film 41 using the peeling tape 35 will be described later, but the surface protective film 41 can be peeled from the optical laminate 1a as follows, for example. First, as shown in FIG. 3, one end of the peeling tape 35 (hereinafter, "mounting end") so as to straddle the side 10a provided with the notch 11b on the surface of the optical laminate 1a on the surface protective film 41 side. It may be called "part".) Subsequently, the end portion of the release tape 35 opposite to the attachment end portion is raised, and the release tape 35 is pulled in the direction from the side 10a to the side 10c (in the direction of the arrow in FIG. 3). As a result, the surface protective film 41 can be peeled off from the optical laminate 1a. In the optical laminate 1a, a notch portion 11b is provided at the end of the side 10a to which the peeling tape 35 is attached. As a result, it is considered that the surface protective film 41 is more likely to be triggered when the peeling tape 35 is triggered, as compared with the case where the notch portion 11b is not provided on the side 10a. Therefore, in the optical laminate 1a, the peeling tape 35 can be prevented from peeling from the surface protective film 41, and the peeling tape 35 can satisfactorily peel the surface protective film 41.

FIG. 4 is a schematic plan view schematically showing another example of the optical laminate of the present embodiment. Although the case where the optical laminate 1a shown in FIG. 1 has one notch portion 11b has been described, it may have two notches, for example, as in the optical laminate 1b shown in FIG. It may have 3 or 4 notches.

The optical laminate 1b shown in FIG. 4 has a notch portion 11d in addition to the notch portion 11b described in the optical laminate 1a shown in FIG. As shown in FIG. 4, the plan view shape of the optical laminate 1b has a shape in which the two corners of the quadrangle 15 are cut out. The notch portion 11b is as described above. The notch portion 11d is a first notch start point P1d (first notch) set on each of the first side 15a and the fourth side 15d, which are two sides constituting the apex Pda of the corner portion of the quadrangle 15. It has a notched shape along a notch line 10ed passing through a start point P1) and a second notch start point P2d (second notch start point P2). The first notch start point P1d and the second notch start point P2d set on the first side 15a and the fourth side 15d have distances Lba and distance Lbd from the apex Pda of 0.1 mm or more and 0.5 mm, respectively. It is located within the following range. The distance Lba and the distance Lbd may be the same as each other or may be different from each other. When the peeling tape 35 (FIG. 3) is attached to the side 10a to peel off the surface protective film 41, it is preferable that the distance Lba is larger than the distance Lbd. The preferred range of the distance Lba and the distance Lbd is the same as the range described for the distance Laa and the distance Lab.

The plan-view shape of the notch line 10ed passing through the first notch start point P1d and the second notch start point P2d is not particularly limited. The notch line 10ed may be a straight line or an arcuate curve like the notch line 10eb. When the notch line 10ed is an arcuate curve, it is preferable that the notch line 10ed is convex toward the corner Pda of the quadrangle 15. The preferred range of the length of the notch line 10ed can be the same as the range described in the notch line 10eb.

The shape of the notch line 10ed is preferably set as follows. In the plan view shape of the optical laminate 1b, when the notch line 10ed is traced from the first notch start point P1d side toward the second notch start point P2d, the first notch start point P1d is located. It is preferable to set the notch line 10ed so that the shortest distance from one side 15a increases continuously or gradually increases while including a section in which the shortest distance is constant. Further, when the notch line 10ed is traced from the first notch start point P1d side toward the second notch start point P2d in the plan view shape of the optical laminate 1b, the second notch start point P2d is positioned. It is preferable to set the notch line 10ed so that the shortest distance from the fourth side 15d is continuously reduced, or is gradually reduced while including a section in which the shortest distance is constant.

The quadrangle 15 set for the plan view shape of the optical laminate 1b is a virtual plane set to include the side of the plan view shape of the optical stack 1b, similarly to the optical stack 1a described above. The shape. A part of the first side 15a, the second side 15b, and the fourth side 15d of the quadrangle 15 shown in FIG. 4 constitutes the side 10a, the side 10b, and the side 10d in the plan view shape of the optical laminate 1b, respectively. The entire third side 15c of the quadrangle 15 constitutes the side 10c in the plan view shape of the optical laminate 1b. In the plan view shape of the optical laminate 1b, the side 10a is a line segment between the first notch start point P1b and the first notch start point P1d of the first side 15a of the quadrangle 15, and the side 10b. Is a portion of the second side 15b of the quadrangle 15 opposite to the side from the second notch start point P2b toward the apex Pab, and the side 10d is the second of the fourth side 15d of the quadrangle 15. It is a portion opposite to the side from the notch start point P2d toward the apex Pda.

The quadrangle 15 includes the intersection formed by extending the side 10a and the side 10b in the plan view shape of the optical laminate 1b as the apex Pab, and includes the intersection formed by extending the side 10d and the side 10a as the apex Pda. .. When the quadrangle 15 is set from the plan view shape of the optical laminate 1b, the side extending from the plan view shape of the optical laminate 1b is cut out from the corner portion of the quadrangle 15 as in the case of the optical laminate 1a. Therefore, assuming that the optical laminate 1b is obtained, the area of the quadrangle 15 notched is set to be the minimum. Further, the shape of the quadrangle set for the optical laminate 1b is set so that the optical laminate 1b can be obtained by notching the two corners of the quadrangle.

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

In the optical laminate 1b, a notch portion 11b and a notch portion 11d are formed at adjacent corners of the quadrangle 15. Therefore, the force required to cause the surface protective film 41 by using the peeling tape 35 in the above procedure is smaller than that when the surface protective film 41 is peeled off in the optical laminate 1a, and the surface protective film 41 is caused. It is thought that it is easier. As a result, in the optical laminate 1b, the surface protective film 41 can be peeled off more satisfactorily by the peeling tape 35.

In the above description, an optical laminate having one or two notches has been described as an example, but the same applies to the plan view shape of the optical laminate having three or four notches. Can be set to a rectangle. When the optical laminate has two or more notches, the shape of the quadrangle is the case where it is assumed that the corners of the quadrangle are notched according to the number of notches of the optical laminate. It is set so that an optical laminate having a number of notches can be obtained.

When the optical laminate has two or more notches, the shapes of the notches may be the same or different from each other. When the optical laminate has two or more notches, at least the two notches are relative to the plan view shape of the optical laminate, such as the

notches

11b and 11d of the optical laminate 1b shown in FIG. It is preferable that the quadrangle is provided so as to cut out two adjacent corners of the quadrangle.

The

optical laminates

1a and 1b (hereinafter, may be referred to as "optical laminate 1" including both) have a shape different from the notch portion as long as it has the notch portion described above. It may have a notched notch shape. For example, the optical laminate 1 passes through the corners of the quadrangle 15 in addition to the notches described above at two points outside the range of lengths described by the distances Laa, Lab, Lba, and Lbd described above. It may have a notch shape notched by a line.

The end face (end face in the stacking direction) of the notch 11 of the optical laminate 1 is preferably a machined surface by a rotary tool. When the end face is a surface cut by a rotary tool, the end faces of the surface protective 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. In this deformed state, the edges of the surface protective film 41 and the polarizing laminate 20 are partially warped or hung down in the lamination direction rather than parallel to the plane direction of the optical laminate 1. Say that. By causing the above deformation on the end face of the optical laminate 1a, the surface protective film 41 can be peeled off even more satisfactorily.

The quadrangle 15 set for the plan view shape of the optical laminate 1 is preferably a square. In the present specification, the square means a quadrangle in which four vertices are right angles (internal angle is 90 °), and 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 quadrangle 15 are each independently preferably 30 mm or more, preferably 40 mm or more, 50 mm or more, 140 mm or more, and 150 mm. It may be the above. Further, it is preferably 200 mm or less, preferably 190 mm or less, 180 mm or less, 80 mm or less, or 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 covers and protects the surface of the polarizing laminate 20 in a manufacturing process of the optical laminate 1a, a manufacturing process of a display device to which the optical laminate 1a is applied, and the like. It is possible to prevent the film from becoming dirty or scratched. The surface protective film 41 can be removed by peeling off the optical laminate 1 after the optical laminate 1 is attached to an adherend such as an image display element of a display device via an adhesive layer 31, for example.

The polarizing laminate 20 includes a polarizing plate 21 having a protective layer on one side or both sides of the linearly polarized light layer. The thickness of the polarizing laminate 20 is 120 μm or less, may be 110 μm or less, may be 100 μm or less, may be 80 μm or less, or may be 40 μm or less. The thickness of the polarizing laminate 20 is usually 5 μm or more, may be 10 μm or more, may be 20 μm or more, may be 40 μm or more, or may be 50 μm or more. When end face processing such as polishing is performed in the manufacturing process of the optical laminate 1, the adhesive constituting the pressure-sensitive adhesive layer 31 squeezes out and covers the end face of the optical laminate 1, and this pressure-sensitive adhesive covers the end face of the optical laminate 1. May reach the end face of. In this case, since the surface protective film 41 is fixed to the adhesive layer 31 by the adhesive covering the end surface of the optical laminate 1, it is considered that the surface protective film 41 is less likely to be peeled off from the optical laminate 1. As the thickness of the polarizing laminate 20 becomes smaller, the distance between the surface protective film 41 and the pressure-sensitive adhesive layer 31 in the stacking direction of the optical laminate 1 becomes smaller. It is considered that the protective film 41 is likely to be difficult to peel off. As described above, the optical laminate 1 has

notches

11b and 11d. Therefore, even when the thickness of the polarizing laminate 20 is small, the surface protective film 41 can be satisfactorily peeled off.

As shown in FIG. 2, the polarizing laminate 20 may be the polarizing plate 21 itself, or may have an optical functional layer other than the polarizing plate 21. Examples of the optical functional layer other than the polarizing plate 21 include a retardation layer; a reflective film; a transflective reflective film; a brightness improving film; an optical compensation film; and a film with an antiglare function.

FIG. 5 is a schematic cross-sectional view schematically showing still another example of the optical laminate of the present embodiment.
The optical laminate shown in FIG. 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 an adhesive layer or an adhesive curing layer. When the polarizing laminate 20 has the retardation layer 22, the retardation layer 22 can be provided on one side 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, and two or more layers may be provided only on one side of the polarizing plate 21. The retardation layer 22 of the above may be provided. 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 having opposite wavelength dispersion, and a positive C plate.

When the retardation layer 22 has an in-plane slow-phase axis, the slow-phase axis may be parallel (0 °) to the absorption axis of the polarizing plate, or may have an angle of more than 0 °. May be good. For example, the slow axis of the retardation layer 22 may have an angle of 15 °, 30 °, 45 °, 60 °, 75 °, or 90 ° with respect 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 can include the polarizing plate 21 and the retardation layer 22. When the polarizing laminate 20 is a circular polarizing plate, the polarizing laminate 20 has the [i] polarizing plate 21, the 1/2 wavelength retardation layer, and the 1/4 wavelength retardation layer from the surface protective film 41 side. It has [iii] polarizing plate 21, positive C plate, and reverse wavelength dispersibility in this order, or has [iii] polarizing plate 21, positive C plate, and reverse wavelength dispersibility in this order. It may have a 1/4 wavelength retardation layer in this order. A laminating layer can be provided between the layers [i] to [iii].

The pressure-sensitive 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 pressure-sensitive adhesive layer 31 is preferably provided so as to be in direct contact with the polarizing laminate 20. In the polarizing laminate 20, when the pressure-sensitive adhesive layer is used for bonding the polarizing plate and the optical functional layer and / or bonding the retardation layers to each other, the pressure-sensitive adhesive layer 31 is the optical laminate 1. The pressure-sensitive adhesive layer is located farthest from the surface protective film 41 in the lamination direction.

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

The optical laminate 1 can be used for a display device such as a smartphone or a smart watch. Examples of the display device include a liquid crystal display device, an organic EL (electroluminescence) display device, and the like. The optical laminate 1 is attached to an adherend such as an image display element of a display device by an adhesive layer 31, and then the surface protective film 41 is peeled off. As a result, the polarized laminate 20 included in the optical laminate 1 can be incorporated into the display device.

(Manufacturing method of optical laminate)
The optical laminate 1 has, for example, a notch in a raw material laminate obtained by cutting a laminate having a surface protective film, a polarizing laminate, an adhesive layer, and a release film in this order into a predetermined shape and size. It can be manufactured by forming. As a method of forming a notch in the raw material laminate, for example, a method of polishing the end face (end face parallel to the stacking direction) of the raw material laminate, or a method of polishing the raw material laminate with a Thomson blade, a laser cutter, or the like. There is a method of cutting by using one kind or a combination of two or more kinds of. Of these, it is preferable to form a notch by polishing in order to suppress fluff and the like generated on the end face of the optical laminate 1 in the lamination direction and to obtain good dimensional accuracy of the optical laminate 1. The above-mentioned polishing and cutting may be performed on one raw material laminate, or two or more raw material laminates may be laminated and performed all at once.

The plan-view shape of the raw material laminate may be selected according to the shape of the optical laminate 1 and is not particularly limited. The plan view shape of the raw material laminate shall be a quadrangle 15 (FIGS. 1 and 4) set for the plan view shape of the optical laminate 1 described above when the notch is formed by polishing. Is preferable, a square shape is more preferable, and a rectangular shape is further preferable. Since the plan view shape of the raw material laminate is the quadrangle 15 described above, the area of the raw material laminate notched can be reduced.

When the optical laminate 1 is manufactured from the raw material laminate having the plan-view shape of the quadrangle 15 described with reference to FIGS. 1 and 4, the corner portion of the quadrangle 15 is a right triangle including the apex Pab and / or the apex Pda (for example, The

notch portions

11b and 11d may be formed by polishing or the like so as to form a notch in the shape of a right-angled isosceles triangle).

FIG. 8 is a schematic perspective view schematically showing an example of the method for manufacturing the optical laminate of the present embodiment.
The manufacturing method for manufacturing the optical laminate 1 by polishing from the raw material laminate is, for example, the following step:
[A] The first step of stacking a plurality of raw material laminates to obtain a laminate W, and [b] the rotation axis R along a direction parallel to the end face of the laminate W and orthogonal to the lamination direction. The second step of cutting the end face of the laminate W by moving the rotary tool 60, which rotates around the center and has a cutting blade, relative to the laminate W.
Can be included.

In the method for manufacturing the optical laminate 1, for example, after performing the first step (above [a]), first, the second step (above [b]) is performed on the four sides of the raw material laminate having a quadrangular plan view shape. After that, the corners of the quadrangle can be polished by the second step ([b] above) to form a notch.

The first step is a step of stacking a plurality of raw material laminates cut into a predetermined shape to obtain a laminate W. The number of raw material laminates contained in the laminate W is not particularly limited, but the laminate W may be, for example, a laminate of 100 to 500 raw material laminates. The raw material laminate may be, for example, obtained by cutting from a long laminate having a layered structure of the raw material laminate.

In the second step, the end face of the laminate W obtained in the first step is cut by the rotary tool 60 to form a cut surface on the end face in the notch portion of the optical laminate 1, and the optical laminate 1 is formed. This is the process of forming.

The cutting process performed in the second step can be performed by a device provided with a support portion 50 and two rotary tools 60, for example, as shown in FIG. The support portion 50 is for pressing the laminate W from above and below to fix the laminate W itself so that it does not move during the cutting process and so that the stacked raw material laminates do not shift. The rotary tool 60 is for cutting the end face of the laminate W, and can rotate about the rotation axis R.

The support portion 50 is a flat plate-shaped substrate (means for moving the laminate W) 51; a gate-shaped frame 52 arranged on the substrate 51; a rotary table arranged on the substrate 51 and rotatable about a central axis. 53; A cylinder 54 provided at a position facing the rotary table 53 on the frame 52 and capable of moving up and down can be provided. The laminate W is sandwiched and fixed by the rotary table 53 and the cylinder 54 via the jig 55.

The rotary tool 60 has a disk-shaped rotating body that rotates around a rotary shaft R. The direction of rotation of the rotating body is the direction indicated by the arrow in FIG. On the board surface of the rotating body (the surface facing the end surface of the laminated body W and parallel to the end surface), a plurality (for example, 2 to 10, preferably 3) are spaced apart in the rotation direction of the rotating body. ~ 7) cutting blades are arranged. The rotation axis R is preferably set so as to pass through the center of the board surface of the rotating body. The cutting blade is provided so as to project from the board surface of the rotating body toward the end surface side of the laminate W, and the rotating body rotates about the rotation axis R in a state where the cutting blade is in contact with the end surface of the laminate W. As a result, the end face of the laminate W can be cut.

Two rotary tools 60 are provided on both sides of the substrate 51 so as to face each other. The rotary tool 60 can be moved in the rotation axis R direction according to the size of the laminate W, and the substrate 51 can be moved so as to pass between the two rotary tools 60. In the cutting process, the laminate W is fixed to the support portion 50, the position of the rotary tool 60 in the rotation axis R direction is appropriately adjusted, and then the rotary tool 60 is rotated around the rotary axis R while rotating the rotary tool 60. The substrate 51 is moved so that the laminate W passes between the rotating tools 60 facing each other. As a result, the cutting blade of the rotary tool 60 is moved relative to the laminate W along the direction parallel to the end face of the laminate W and orthogonal to the stacking direction. It is possible to perform a cutting process in which these end faces are scraped off by abutting against the exposed end faces of W facing each other.

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

(Peeling method of surface protective film)
FIG. 7 is a schematic cross-sectional view schematically showing an example of a step of peeling the surface protective film from the optical laminate of the present embodiment. The peeling method for peeling the surface protective film 41 from the optical laminate 1 includes a step of attaching the optical laminate 1 to the image display element 45 (adhesive body) by the adhesive layer 31 (FIG. 7), and the optical laminate 1 The optical laminate attached to the image display element 45 by the step of attaching the peeling tape 35 to the surface of the surface protective film 41 side ((a) of FIGS. 3 and 7) and by inducing the peeling tape 35. The step of peeling the surface protective film 41 from 1 ((b) and (c) of FIG. 7) is included.

In the step of attaching the peeling tape 35, the peeling tape 35 is attached so as to straddle one side provided with the notch portion 11b or the notch portion 11d at the end portion 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 the side having the

notch portion

11b or 11d at the end (for example, the side 10b shown in FIGS. 1 and 4 and FIG. 4). It may be the side 10d) shown in. As shown in FIG. 4, when the notch portions 11b and the notch portions 11d are provided at both ends of the side 10a, the surface protective film 41 can be peeled off more satisfactorily by causing the peeling tape 35. The peeling tape 35 is preferably attached so as to straddle the side 10a. The peeling tape 35 is usually attached directly to the surface of the surface protective film 41.

When the optical laminate 1 has the release film 32 (FIG. 6), the step of bonding to the image display element 45 is performed after the release film 32 is peeled 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 step of peeling the surface protective film 41, the end portion of the peeling tape 35 opposite to the mounting end portion, which is the end portion attached to the surface on the surface protective film 41 side (hereinafter, "grip side end portion"). The peeling tape is held on the side opposite to the image display element 45 side (the direction on the upper right side in (a) of FIG. 7 and the direction of the arrow in (a) of FIG. 7). Causes 35. The gripping side end of the peeling tape 35 is folded back toward the mounting end side (in the direction of the arrow in (b) of FIG. 7), and pulled in the direction of this folding back (in the direction of the arrow in (c) of FIG. 7). As a result, the surface protective film 41 can be peeled off from the optical laminate 1 to expose the surface of the polarizing laminate 20.

The surface protective film 41 may be peeled off manually, but it can be automated by using a peeling device. When a peeling device is used, the surface protective film 41 is formed by gripping the gripping side end of the peeling tape 35 with the chuck of the peeling device and causing the peeling tape 35 by relatively moving the chuck and the optical laminate 1. Can be peeled off.

As described above, the peeling tape 35 is used by attaching the peeling tape 35 to the side where the cutout portion 11b and / or the cutout portion 11d is provided at the end portion in the plan view shape of the optical laminate 1. The force required to raise the surface protective film 41 can be reduced. Therefore, according to the peeling method of the present embodiment, the surface protective film can be peeled better than the case where the surface protective film is peeled from the optical laminate having no notch. In particular, when the notch portions 11b and the notch portions 11d are provided at both ends of the side 10b as in the optical laminate 1b shown in FIG. 4, the peeling tape 35 can be attached to the side 10b to further increase the thickness. The surface protective film 41 can be satisfactorily peeled off.

Hereinafter, details of each member used in the method for peeling the optical laminate and the surface protective film of the present embodiment will be described.

(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, it is preferable that the surface protective film is provided on the polarizing plate. The surface protective film may be a resin film for a surface protective film on which an adhesive layer is formed, or may be formed by a self-adhesive film alone. The thickness of the surface protective film can be, for example, 30 to 200 μm, preferably 30 to 150 μm, and more preferably 30 to 120 μm.

Examples of the resin constituting the surface protective film resin film include polyolefin resins such as polyethylene resins and polypropylene resins; cyclic polyolefin resins; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; and polycarbonate resins. ; (Meta) acrylic resin and the like can be mentioned. Of these, polyester resins such as polyethylene terephthalate are preferable. The resin film for a surface protective film may have a one-layer structure, but may have a multi-layer structure of two or more layers. The resin film for the surface protective film may be a film that has been subjected to a stretching treatment such as uniaxial stretching or biaxial stretching.

The adhesion (Fp) of the surface protective 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, and may be 0.03 N / 25 mm or more. It may be 0.08 N / 25 mm or more, preferably 0.5 N / 25 mm or less, 0.4 N / 25 mm or less, or 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 × 25 mm and bonded to a non-alkali glass substrate (thickness 0.7 mm, “Eagle XG” manufactured by Corning Inc.) with an adhesive layer 31 to obtain a test piece. This test piece was 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 heating and pressurizing environment. Store for 24 hours to use as an evaluation sample. This evaluation sample is a peeling device ("Autograph AGS-50NX" manufactured by Shimadzu Corporation, in accordance with JIS K6854-2: 1999 "Adhesive-Peeling Adhesive Strength Test Method-Part 2: 180 ° Peeling". ) Is used to perform a 180 ° peeling test at a moving speed of 300 mm / min, and the peeling force measured is defined as the adhesion force (Fp).

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

The above-mentioned surface protective film can be obtained by forming an adhesive layer on the surface of the resin film for the surface protective film by applying an adhesive, drying, or the like. If necessary, a surface treatment (for example, corona treatment) may be applied to the surface to which the adhesive of the resin film for the surface protective film is applied in order to improve the adhesion, and the primer layer (also referred to as the undercoat layer) may be applied. A thin layer such as) may be formed. Further, if necessary, when the surface protective film has an adhesive layer, it has a release layer for covering and protecting the surface of the adhesive layer on the side opposite to the resin film side for the surface protective film. You may be doing it. This peeling layer can be peeled off at an appropriate timing when it is bonded to the polarizing laminate.

The self-adhesive film that can be used as a surface protective film is a film that can adhere to itself and maintain its adhered state without providing a means for adhering an adhesive layer or the like. The self-adhesive film can be formed by using, for example, a polypropylene-based resin, a polyethylene-based resin, or the like.

(Polarizing laminate)
The polarizing laminate includes at least a polarizing plate having a protective layer on one side 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. An adhesive layer or an adhesive curing layer is between the linearly polarizing layer and the protective layer, between the polarizing plate and the optical functional layer, and between the optical functional layers when two or more optical functional layers are laminated. It may be bonded through a bonding layer such as.

(Straightly polarized layer)
The linearly polarized light layer has a property of transmitting linearly polarized light having a vibration plane orthogonal to the absorption axis when unpolarized light is incident. The linearly polarizing layer may contain a polyvinyl alcohol (hereinafter, may be abbreviated as “PVA”) resin film, and a dichroic dye is oriented on the polymerizable liquid crystal compound to obtain the polymerizable liquid crystal compound. It may be a polymerized cured film.

Examples of the linear polarizing layer containing the PVA-based resin film include hydrophilic polymer films such as PVA-based films, partially formalized PVA-based films, and ethylene-vinyl acetate copolymerization-based partially saponified films, as well as iodine and bicolor. Examples thereof include those subjected to a dyeing treatment with a bicolor substance such as a dye and a stretching treatment. Since it is excellent in optical characteristics, it is preferable to use a linearly polarizing layer obtained by dyeing a PVA-based resin film with iodine and uniaxially stretching it.

The PVA-based resin can be produced by saponifying the polyvinyl acetate-based resin. The polyvinyl acetate-based resin can be a copolymer of vinyl acetate and another monomer copolymerizable with vinyl acetate, in addition to polyvinyl acetate which is a homopolymer of vinyl acetate. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides having an ammonium group.

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 also 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 1000, it is difficult to obtain preferable polarization performance, and if it exceeds 10,000, the film processability may be inferior.

As another method for producing a linear polarizing layer containing a PVA-based resin film, a base film is first prepared, a resin solution such as PVA-based resin is applied onto the base film, and drying is performed to remove the solvent. Examples thereof include a step of forming a resin layer on a base film.
A primer layer can be formed in advance on the surface of the base film on which the resin layer is formed. As the base film, a resin film such as PET or a film using a thermoplastic resin that can be used for the protective layer described later can be used. Examples of the material of the primer layer include a resin obtained by cross-linking a hydrophilic resin used for the linearly polarizing layer.

Then, if necessary, the amount of solvent such as water content of the resin layer is adjusted, then the base film and the resin layer are uniaxially stretched, and then the resin layer is dyed with a dichroic dye such as iodine to obtain two colors. The sex dye is adsorbed and oriented on the resin layer. Next, if necessary, the resin layer in which the dichroic dye is adsorbed and oriented is treated with a boric acid aqueous solution, and a washing step of washing off the boric acid aqueous solution is performed. As a result, a film of a resin layer in which the dichroic dye is adsorption-oriented, that is, a linearly polarizing layer is produced. A known method can be adopted for each step.

The uniaxial stretching of the base film and the resin layer may be performed before dyeing, during dyeing, or during boric acid treatment after dyeing, and each of these multiple steps is uniaxial. Stretching may be performed. The base film and the resin layer may be uniaxially stretched in the MD direction (film transport direction), in this case, uniaxially stretched between rolls having different peripheral speeds, or uniaxially stretched using a thermal roll. You may. Further, the base film and the resin layer may be uniaxially stretched in the TD direction (direction perpendicular to the film transport direction), and in this case, the so-called tenter method can be used. Further, the stretching of the base film and the resin layer may be a dry stretching in which the resin layer is stretched in the air, or a wet stretching in which the resin layer is swollen with a solvent. In order to exhibit the performance of the linearly polarized light layer, the draw 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 draw ratio, but it is preferably 8 times or less from the viewpoint of suppressing breakage and the like.

The linearly polarized light layer produced by the above method can be obtained by laminating a protective layer described later and then peeling off the base film. According to this method, the linearly polarizing layer can be further thinned.

The thickness of the linearly polarizing layer containing the PVA-based resin film is preferably 1 μm or more, preferably 2 μm or more, 5 μm or more, and preferably 30 μm or less, preferably 15 μm or less. It 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 on a polymerizable liquid crystal compound and polymerizing the polymerizable liquid crystal compound, the polymerizable liquid crystal compound and the dichroic dye are placed on a base film. Examples thereof include a method of applying the composition for forming a polarizing layer containing the mixture, polymerizing and curing the polymerizable liquid crystal compound while maintaining the liquid crystal state, and forming a linear polarizing layer. The linearly polarizing layer thus obtained is in a state of being laminated on the base film, and the linearly polarizing layer with the base film may be used as a polarizing plate to be described later. As the base film, a resin film such as PET or a film using a thermoplastic resin that can be used for the protective layer described later can be used.

As the dichroic dye, a dye having a property that the absorbance in the major axis direction and the absorbance in the minor axis direction of the molecule are different can be used. For example, a dye having an absorption maximum wavelength (λmax) in the range of 300 to 700 nm. Is preferable. Examples of such a dichroic dye include an acridine dye, an oxazine dye, a cyanine dye, a naphthalene dye, an azo dye, an anthraquinone dye, and the like, and among them, the azo dye is preferable. Examples of the azo dye include a monoazo dye, a bisazo dye, a trisazo dye, a tetrakisazo dye, a stilbene azo dye, and the like, and a bisazo dye and a trisazo dye are more preferable.

The composition for forming a polarizing layer may contain a solvent, a polymerization initiator such as a photopolymerization initiator, a photosensitizer, a polymerization inhibitor and the like. As the polymerizable liquid crystal compound, the dichroic dye, the solvent, the polymerization initiator, the photosensitizer, the polymerization inhibitor and the like contained in the composition for forming the polarizing layer, known ones can be used, for example, specially. Those exemplified in Japanese Patent Application Laid-Open No. 2017-102479 and Japanese Patent Application Laid-Open No. 2017-83843 can be used. Further, as the polymerizable liquid crystal compound, the compound exemplified as the polymerizable liquid crystal compound used for obtaining the cured product layer as the retardation layer described later may be used. As a method for forming a linearly polarized light layer using the polarizing layer forming composition, the method exemplified in the above publication can also be adopted.

(Polarizer)
The linearly polarized light layer can be formed as a polarizing plate by laminating a protective layer on one side or both sides thereof. This polarizing plate is a so-called linear polarizing plate. The protective layer that can be laminated on one side or both sides of the linearly polarizing layer is formed of, for example, a thermoplastic resin having excellent transparency, mechanical strength, thermal stability, moisture barrier property, isotropic property, stretchability, and the like. Film is used. Specific examples of such thermoplastic resins include cellulose resins such as triacetyl cellulose; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polyether sulfone resins; polysulfone resins; polycarbonate resins; polyamides such as nylon and aromatic polyamides. Resin; Polygon resin; Polyethylene resin such as polyethylene, polypropylene, ethylene / propylene copolymer; Cyclic polyolefin resin having cyclo-based and norbornene structure (also referred to as norbornene-based resin); (meth) acrylic resin; polyallylate resin; polystyrene resin Polyvinyl alcohol resins, as well as mixtures thereof, can be mentioned.
When the 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 addition, in this specification, "(meth) acrylic" means that either acrylic or methacryl may be used. "(Meta)" such as (meth) acrylate has the same meaning.

The protective layer may have a phase difference characteristic, or may have a functional layer such as a hard coat layer or an antireflection 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, more preferably 30 μm or less. The above-mentioned upper limit value and lower limit value can be arbitrarily combined.

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

When the retardation layer contains a cured product 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, and one of these can be used. Alternatively, a mixture containing both of these may be used. When the rod-shaped polymerizable liquid crystal compound is horizontally or vertically oriented with respect to the base material layer, the optical axis of the polymerizable liquid crystal compound coincides with the major axis direction of the polymerizable liquid crystal compound. When the disk-shaped polymerizable liquid crystal compound is oriented, the optical axis of the polymerizable liquid crystal compound exists in a direction orthogonal 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 No. 11-513019 (Claim 1 and the like) can be preferably used. Examples of the disk-shaped polymerizable liquid crystal compound are described in JP-A-2007-108732 (paragraphs [0020] to [0067], etc.) and JP-A-2010-244038 (paragraphs [0013] to [0108], etc.). Can be preferably used.

In order for the cured product layer formed by polymerizing the polymerizable liquid crystal compound to exhibit an in-plane retardation, the polymerizable liquid crystal compound may be oriented in an appropriate direction. When the polymerizable liquid crystal compound is rod-shaped, an in-plane phase difference is developed by orienting the optical axis of the polymerizable liquid crystal compound horizontally with respect to the plane of the substrate layer. In this case, the optical axis direction and the slow axis It matches the direction. When the polymerizable liquid crystal compound has a disk shape, an in-plane phase difference is developed by orienting the optical axis of the polymerizable liquid crystal compound horizontally with respect to the plane of the substrate layer. In this case, the optical axis and the slow axis Is orthogonal to. The orientation state of the polymerizable liquid crystal compound can be adjusted by the combination of the alignment layer and the polymerizable liquid crystal compound.

The polymerizable liquid crystal compound is a compound having at least one polymerizable group and having liquid crystallinity. When two or more kinds of polymerizable liquid crystal compounds are used in combination, it is preferable that at least one kind has two or more polymerizable groups in the molecule. The polymerizable group means a group involved in the polymerization reaction, and is preferably a photopolymerizable group. Here, the photopolymerizable group refers to a group that can participate in the polymerization reaction by an active radical, an acid, or the like 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 oxylanyl group, an oxetanyl group, a styryl group and an allyl group. Be done. Of these, an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxylanyl group and an oxetanyl group are preferable, and an acryloyloxy group is more preferable. The liquid crystal property of the polymerizable liquid crystal compound may be a thermotropic liquid crystal or a lyotropic liquid crystal, and when the thermotropic liquid crystal is classified by order, it may be a nematic liquid crystal or a smectic liquid crystal.

When the retardation layer contains a cured product layer of a polymerizable liquid crystal compound, the retardation layer may include an orientation layer. The alignment layer has an orientation regulating force that orients the polymerizable liquid crystal compound in a desired direction. The oriented layer may be a vertically oriented layer in which the molecular axis of the polymerizable liquid crystal compound is vertically oriented with respect to the base material layer, or a horizontally oriented layer in which the molecular axis of the polymerizable liquid crystal compound is horizontally oriented with respect to the base material layer. It may be a tilt-oriented layer in which the molecular axis of the polymerizable liquid crystal compound is tilt-oriented with respect to the base material layer. The first oriented layer and the second oriented layer may be the same oriented layer or may be different oriented layers.

The alignment layer preferably has solvent resistance that does not dissolve due to coating of the liquid crystal layer forming composition, and has heat resistance to heat treatment for removing the solvent and aligning the polymerizable liquid crystal compound. Examples of the oriented layer include an oriented polymer layer formed of an oriented polymer, a photo-oriented polymer layer formed of a photo-aligned polymer, and a grub-oriented layer having an uneven pattern or a plurality of grubs (grooves) on the layer surface. Can be done.

The cured product layer of the polymerizable liquid crystal compound can be formed by applying a liquid crystal layer forming composition containing the polymerizable liquid crystal compound on the base material layer, drying the composition, and polymerizing the polymerizable liquid crystal compound. The liquid crystal layer forming composition may be applied on the alignment layer formed on the base material layer.

As the base material layer, a film formed of a resin material can be used, and examples thereof include a film using the resin material described as the thermoplastic resin used for forming the protective layer described above. The thickness of the base material layer is not particularly limited, but is generally preferably 1 to 300 μm or less, more preferably 20 to 200 μm, and 30 to 120 μm from the viewpoint of workability such as strength and handleability. Is even more preferable. The base material layer may be incorporated into the polarizing laminate as a retardation layer together with the cured product layer of the polymerizable liquid crystal compound, and the base material layer may be peeled off to form only the cured product layer of the polymerizable liquid crystal compound, or The cured product layer and the oriented layer may be incorporated into the polarizing laminate as a retardation layer.

Examples of the resin film used for the stretched resin film include a film made of a thermoplastic resin that can be used to form a protective layer. Examples of the stretching treatment include uniaxial stretching and biaxial stretching. The stretching direction in the stretching treatment may be the length direction of the unstretched resin, the direction orthogonal to the length direction, or the direction obliquely intersecting with the length direction. In the case of uniaxial stretching, the unstretched resin may be stretched in any of these directions. The biaxial stretching may be simultaneous biaxial stretching in which two of these directions are simultaneously stretched, or sequential biaxial stretching in which stretching is performed in a predetermined direction and then in the other direction.

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

(Lated layer)
Examples of the bonding layer for bonding the layers contained in the polarizing laminate include an adhesive layer and an adhesive curing layer. When the bonding layer is a pressure-sensitive adhesive layer, it can be formed by using the pressure-sensitive adhesive described in the pressure-sensitive adhesive layer 31 described later. The adhesion of the pressure-sensitive adhesive layer as a bonding layer to a non-alkali glass substrate (thickness 0.7 mm, Corning's "Eagle XG") at a temperature of 23 ° C. and a relative humidity of 55% is preferably 1 N / 25 mm or more. , 3N / 25mm or more, 10N / 25mm or more, preferably 50N / 25mm or less, 40N / 25mm or less, 30N / 25mm or less. May be good. Adhesive force can be measured in accordance with JIS K 6854-2: 1999 "Adhesive-Peeling Adhesive Strength Test Method-Part 2: 180 ° Peeling". Further, the adhesion to the adherend other than the non-alkali glass substrate (thickness 0.7 mm, "Eagle XG" manufactured by Corning Inc.) can be regarded as the same as the adhesion to the general non-alkali glass substrate.

The adhesion (Fb) between the bonding layer to which each layer constituting the polarizing laminate is bonded and the layers bonded to the bonding layer is usually the adhesion of the surface protective film 41 to the polarizing laminate 20. Greater than (Fp). 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. Further, the adhesive force (Fa) of the pressure-sensitive adhesive layer 31 to the image display element 45 (adhesive body), which will be described later, is usually the same as the adhesive force (Fb), and the adhesive force (Fp) of the surface protective film 41 to the polarizing laminate 20 is the same. ) Is larger than. The difference between the adhesion force (Fa) and the adhesion force (Fp) is, for example, 1N / 25mm or more, preferably 3N / 25mm or more, and usually 50N / 25mm or less.

When the adhesive force (Fb) is smaller than the adhesive force (Fp), the polarizing laminate is formed when the surface protective film 41 is peeled off after the optical laminate 1 is attached to the image display element 45 by the adhesive layer 31. There is a possibility that the layers constituting 20 may be separated from each other. When the adhesive force (Fa) is smaller than the adhesive force (Fp), the adhesive is applied when the surface protective film 41 is peeled off after the optical laminate 1 is attached to the image display element 45 by the adhesive layer 31. Peeling may occur between the layers of the layer 31 and the image display element 45.

The adhesion (Fa) may be larger, smaller, or the same as the adhesion (Fb). When the adhesion force (Fa) is smaller than the adhesion force (Fb), a rework or the like in which the polarizing laminate 20 bonded to the image display element 45 is peeled off from the image display element 45 and a new optical laminate 1 is bonded. Can be easily performed.

The storage elastic modulus of the pressure-sensitive adhesive layer as a bonding 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. It may be 0.25 MPa or less, or 0.2 MPa or less. The storage elastic modulus is based on JIS K7244-6, which is a measurement sample obtained by punching a 0.2 mm-thick pressure-sensitive adhesive layer laminate produced by laminating a plurality of pressure-sensitive adhesive layers into a cylinder having a diameter of 8 mm. , A commercially available viscoelasticity measuring device can be used for measurement under the following conditions.
Normal force FN: 1N
Distortion γ: 1%
Frequency: 1Hz
Temperature: 80 ° C

The thickness of the pressure-sensitive adhesive layer as the bonding layer is preferably 5 μm or more, 10 μm or more, 15 μm or more, 50 μm or less, and 25 μm or less. It may be 20 μm or less.

When the bonding layer is an adhesive curing layer, the adhesive curing layer can be formed by curing the curable component in the adhesive composition. Examples of the adhesive composition for forming the adhesive curing layer include adhesives other than pressure-sensitive adhesives (adhesives), such as water-based adhesives and active energy ray-curable adhesives.

Examples of the water-based adhesive include an adhesive in which a polyvinyl alcohol-based resin is dissolved or dispersed in water. The drying method when a water-based adhesive is used is not particularly limited, but for example, a method of drying using a hot air dryer or an infrared dryer can be adopted.

Examples of the active energy ray-curable adhesive include solvent-free active energy ray-curable adhesives containing curable compounds that are cured by irradiation with active energy rays such as ultraviolet rays, visible light, electron beams, and X-rays. Can be mentioned. By using a solvent-free active energy ray-curable adhesive, the adhesion between layers can be improved.

The active energy ray-curable adhesive preferably contains one or both of a cationically polymerizable curable compound and a radically polymerizable curable compound because it exhibits good adhesiveness. The active energy ray-curable adhesive may further contain a cationic polymerization initiator for initiating the curing reaction of the curable compound, or a radical polymerization initiator.

Examples of the cationically polymerizable curable compound include an epoxy compound (a compound having one or more epoxy groups in the molecule) and an oxetane compound (one or two or more oxetane rings in the molecule). Compounds having), or a combination thereof.

Examples of the radically polymerizable curable compound include (meth) acrylic compounds (compounds having one or more (meth) acryloyloxy groups in the molecule), radically polymerizable double bonds, and others. Vinyl-based compounds of the above, or combinations thereof can be mentioned.

The active energy ray-curable adhesive can contain a sensitizer if necessary. By using the sensitizer, the reactivity can be improved, and the mechanical strength and the adhesive strength of the adhesive cured layer can be further improved. As the sensitizer, known ones can be appropriately applied. When the sensitizer is blended, the blending amount is preferably in the range of 0.1 to 20 parts by mass with respect to 100 parts by mass of the total amount of the active energy ray-curable adhesive.

Active energy ray-curable adhesives, if necessary, ion trapping agents, antioxidants, chain transfer agents, tackifiers, thermoplastic resins, fillers, flow regulators, plasticizers, defoamers, antistatics. It can contain additives such as agents, leveling agents, and solvents.

When an active energy ray-curable adhesive is used, it is possible to irradiate active energy rays such as ultraviolet rays, visible light, electron beams, and X-rays to cure the adhesive composition layer to form an adhesive layer. can. As the active energy ray, ultraviolet rays are preferable, and as a light source in this case, 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 can be used. can.

(Adhesive layer)
The pressure-sensitive adhesive layer 31 included in the optical laminate is a layer formed by using a pressure-sensitive adhesive. In the present specification, the "adhesive" expresses adhesiveness by sticking itself to an adherend such as an image display element, and is a so-called pressure-sensitive adhesive. Further, the active energy ray-curable pressure-sensitive adhesive described later can adjust the degree of cross-linking and the adhesive force by irradiating with energy rays.

As the pressure-sensitive adhesive, a conventionally known pressure-sensitive adhesive having excellent optical transparency can be used without particular limitation. For example, a pressure-sensitive adhesive having a base polymer such as acrylic, urethane, silicone, or polyvinyl ether is used. be able to. Further, it may be an active energy ray-curable pressure-sensitive adhesive, a thermosetting pressure-sensitive adhesive or the like. Among these, an adhesive based on an acrylic resin having excellent transparency, adhesive strength, removability (hereinafter, also referred to as reworkability), weather resistance, heat resistance and the like is preferable. The pressure-sensitive adhesive layer is preferably composed of a reaction product of a pressure-sensitive adhesive composition containing a (meth) acrylic resin, a cross-linking agent, and a silane compound, and may contain other components.

The pressure-sensitive adhesive layer 31 may be formed by using an active energy ray-curable pressure-sensitive adhesive. The active energy ray-curable pressure-sensitive adhesive is a harder pressure-sensitive adhesive by blending a pressure-sensitive adhesive composition with an ultraviolet-curable compound such as a polyfunctional acrylate, forming a pressure-sensitive adhesive layer, and then irradiating the pressure-sensitive adhesive with ultraviolet rays to cure the pressure-sensitive adhesive. Layers can be formed. The active energy ray-curable pressure-sensitive adhesive has a property of being cured by being irradiated with energy rays such as ultraviolet rays and electron beams. Since the activated energy ray-curable adhesive has adhesiveness even before irradiation with energy rays, it adheres to an adherend such as an image display element and is cured by irradiation with energy rays to adjust the adhesion force. It is a pressure-sensitive adhesive having the property of being able to.

The active energy ray-curable pressure-sensitive adhesive generally contains an acrylic pressure-sensitive adhesive and an energy ray-polymerizable compound as main components. Usually, a cross-linking agent is further blended, and if necessary, a photopolymerization initiator, a photosensitizer, or the like can be blended.

As the pressure-sensitive adhesive layer 31, it is possible to use a pressure-sensitive adhesive layer 31 having an adhesion force (Fa) to the image display element 45 (adhesive body) relatively larger than the adhesion force (Fp) to the polarizing laminate of the surface protective film described above. preferable. Further, it is preferable to use a pressure-sensitive adhesive layer 31 having a storage elastic modulus or thickness relatively larger than the storage elastic modulus or thickness of the pressure-sensitive adhesive layer as a bonding layer contained in the above-mentioned polarizing laminate. ..

The adhesive force of the pressure-sensitive adhesive layer 31 to a non-alkali glass substrate (thickness 0.7 mm, Corning's "Eagle XG") at a temperature of 23 ° C. and a relative humidity of 55% is preferably 5 N / 25 mm or more, preferably 8 N / 25 mm. It may be 10 N / 25 mm or more, preferably 50 N / 25 mm or less, 40 N / 25 mm or less, or 30 N / 25 mm or less. The storage elastic modulus of the pressure-sensitive adhesive layer 31 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, preferably 0.25 MPa or less. It may be 0.2 MPa or less. As a method for measuring the adhesive force and the storage elastic modulus, the method for measuring the adhesive force and the storage elastic modulus described in the above-mentioned bonding layer can be used. The thickness of the pressure-sensitive adhesive layer 31 is preferably 10 μm or more, 15 μm or more, 20 μm or more, 40 μm or less, and 35 μm or less. It may be 30 μm or less. Further, the adhesion to the adherend other than the non-alkali glass substrate (thickness 0.7 mm, "Eagle XG" manufactured by Corning Inc.) can be regarded as the same as the adhesion to the general non-alkali glass substrate.

(Release film)
The release film covers and protects the pressure-sensitive adhesive layer or supports the pressure-sensitive adhesive layer, and has a function as a separator that can be peeled off from the pressure-sensitive adhesive layer. Examples of the release film include a film in which the surface of the base film on the pressure-sensitive adhesive layer side is subjected to a mold release treatment such as a silicone treatment. Examples of the resin material forming the base film include the same resin materials as those forming the protective layer described above. The resin film may have a one-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.

Information on the optical laminate may be displayed on the release film by printing or the like. Examples of the information regarding the optical laminate include a display regarding the type of the polarizing laminate included in the optical laminate, a display indicating the direction of the absorption axis of the polarizing plate included in the polarizing laminate, and the like.

(Peeling tape)
As the peeling tape, an adhesive tape having an adhesive layer formed on one side of the resin film can be used. As the resin film, those exemplified as the resin film for the surface protective film of the surface protective film can be used. The pressure-sensitive adhesive layer can be formed by using the pressure-sensitive adhesive described in the pressure-sensitive adhesive layer 31.

(Subject)
The adherend to which the optical laminate is bonded by the pressure-sensitive adhesive layer 31 is not particularly limited, and examples thereof include an image display element of a display device. The image display element can be selected according to the type of display device. Examples of the image display element include a display element such as a liquid crystal cell or an organic EL display element.

Hereinafter, the present invention will be described in more detail 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 laminates obtained in Examples and Comparative Examples, and the optical laminate was bonded to a glass plate (holding table) with an exposed adhesive layer to prepare a test sample. A peeling tape (cellotape (registered trademark) (CT405-AP24), manufactured by Nichiban Co., Ltd.) was attached to the surface protective film on the surface of the optical laminate of the test sample. The peeling tape has a size of 24 mm in width and 100 mm in length, and has a notch at the center of the short side provided with the notch in the plan view shape of the optical laminate of the test sample. A surface protection film that straddles the short side and has a length range of 10 mm from one end in the length direction of the peeling tape as the mounting end. It was mounted so that it was placed on the surface (see FIG. 3). In the comparative example, the peeling tape was attached to the center position of one of the short sides in the same manner as described above.

Of the peeling tape, the gripping side end on the side opposite to the mounting end of the optical laminate is gripped by the chuck of the peeling device (Autograph AGS-50NX, manufactured by Shimadzu), and the angle with respect to the surface direction of the optical laminate ( A peeling test was conducted in which the peeling angle) was 180 ° and the peeling speed was 300 mm / min, and the peeling tape was pulled in the direction facing the other short side facing the short side to which the peeling tape was attached. As a result of the peeling test, the case where the surface protective film is peeled from the test sample is evaluated as A, and the case where the peeling tape is peeled from the surface protective film and the surface protective film is not peeled from the test sample is evaluated as B. evaluated. This peeling test was performed on 10 or 20 test samples, and the peeling defect rate was calculated by the following formula:
Peeling defect rate [%] = (number of evaluation B / number of peeling tests) x 100
It was calculated based on.

[Example 1]
(Preparation of raw material laminate)
A linearly polarized light layer (thickness 8 μm) in which iodine was adsorbed and oriented on a polyvinyl alcohol-based resin film was prepared. A cyclic olefin resin (COP) film (thickness 25 μm) (hereinafter, “25HC-COP”) in which a hard coat (HC) layer as a protective layer is formed on one surface of the linearly polarized light layer via an aqueous adhesive. The COP film side (the side opposite to the HC layer side) of "film") was bonded. On the HC layer of this protective layer, the acrylic pressure-sensitive adhesive layer side of the surface protective film (thickness 53 μm) in which the acrylic pressure-sensitive adhesive layer (thickness 15 μm) was formed on the polyester-based resin film (thickness 38 μm) was bonded. A triacetyl cellulose (TAC) film (thickness 20 μm) as a protective layer was attached to the other surface of the linearly polarized light layer via an aqueous adhesive. As a result, a polarizing plate (1) with a surface protective film was obtained. In the polarizing plate (1) with a surface protective film, a surface protective film (polyester resin film, acrylic pressure-sensitive adhesive layer), a 25HC-COP film (HC layer, COP film), a linearly polarizing layer, and a TAC film are laminated in this order. It was done.

Next, a λ / 4 plate (thickness 2 μm) which is a cured product layer of a polymerizable liquid crystal compound, an adhesive cured layer (thickness 2 μm) of an ultraviolet curable adhesive, and a positive which is a cured product layer of a polymerizable liquid crystal compound. A retardation layer in which C plates (thickness 3 μm) were laminated in this order was prepared. The TAC film of the polarizing plate (1) with a surface protective film and the λ / 4 plate of the retardation layer were bonded by a bonding layer (thickness 17 μm) which was an adhesive layer. Subsequently, a pressure-sensitive adhesive layer (1) with a release film was prepared by forming a pressure-sensitive adhesive layer (thickness 25 μm) formed on a release film (thickness 38 μm) using an acrylic pressure-sensitive adhesive. The pressure-sensitive adhesive layer of the pressure-sensitive adhesive layer (1) with a release film is bonded to the positive C plate side of the retardation layer bonded to the polarizing plate (1) with a surface protective film, and the length of the long side is 37 mm. A raw material laminate (1) was obtained by cutting into a rectangle having a short side length of 35 mm. The raw material laminate (1) is a polarizing plate with a surface protective film (1) (surface protective film, 25HC-COP film, linear polarizing layer, and TAC film), a bonding layer which is an adhesive layer, and a retardation layer (λ). A / 4 plate, a bonding layer, a positive C plate), and an adhesive layer (1) with a release film (adhesive layer, release film) were laminated in this order. The thickness of the laminated portion of the raw material laminate (1) from the polarizing plate (25HC-COP film, linearly polarized light layer, TAC film) to the retardation layer (λ / 4 plate, bonded layer, positive C plate) is 77 μm. Met. Further, the direction of the long side of the raw material laminate (1) was parallel to the absorption axis of the linearly polarized light layer.

(Preparation of optical laminate)
Using the apparatus shown in FIG. 8, a laminate W in which the raw material laminates are laminated according to the procedure of the first step (above [a]) described above is prepared, and the second step (above [b]) described above. ), The end faces corresponding to the four sides of the raw material laminate were polished. Further, according to the procedure of the second step (above [b]) described above, one corner portion at one end of one short side of the raw material laminate is polished to form one notch portion. An optical laminate having was obtained. The corners are polished by 0.3 mm (distance Laa and distance Lab in FIG. 1) from the apex of the corner of the raw material laminate after polishing to the end faces corresponding to the four sides in the short side direction and the long side direction, respectively. The first notch start point P1 and the second notch start point P2 are set at the positions (see the first notch start point P1b and the second notch start point P2b in FIG. 1), and the first notch start point is set. It was performed along a linear notch line connecting P1 and the second notch start point P2. In each of the above polishings, the relative moving speed between the laminate W and the rotating tool 60 was set to 2100 mm / min, and the rotating speed of the rotating tool was set to 5400 rpm. The obtained optical laminate was evaluated for peeling. 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 is peeled off from the optical laminate obtained above to expose the pressure-sensitive adhesive layer, and the optical laminate from which the release film has been removed is attached to a glass plate (holding table) by the exposed pressure-sensitive adhesive layer for testing. It was used as a sample. A 180 ° peeling test (peeling) using the peeling device described in the peeling evaluation section is performed by adhering the peeling tape described in the peeling evaluation section to the surface of the surface protective film of the test sample. The adhesive force between the surface protective film and the peeling tape was measured by an angle of 180 ° and a peeling speed of 300 mm / min). This adhesion was 9N / 25mm. When the peeling tape was peeled off, the surface protective film was not peeled off from the polarizing laminate.

Further, the adhesion between the acrylic pressure-sensitive adhesive layer side of the surface protective film and the HC layer side of the 25HC-COP film is a 180 ° peeling test (peeling angle 180) using the peeling device described in the peeling evaluation section above. °, peeling speed 300 mm / min), and it was 0.03 N / 25 mm.

[Example 2]
The optical laminate is the same as in Example 1 except that the two corners on both ends of one short side of the raw material laminate (1) are polished to form two notches. Got In each of the two notches, as in the first embodiment, the first notch start point P1 and the second cut from the apex of the corner of the raw material laminate (1) after polishing the end faces corresponding to the four sides. The distance to the notch start point P2 was 0.3 mm, and the notch line connecting the first notch start point P1 and the second notch start point P2 was a straight line. Peeling evaluation was performed on the optical laminate. The results are shown in Table 1.

[Example 3]
The distances from the apex of the corner of the raw material laminate (raw material laminate after polishing the end faces corresponding to the four sides) to the first notch start point P1 and the second notch start point P2 were set to 0.2 mm, respectively. An optical laminate was obtained in the same manner as in Example 2 except for the above. Peeling evaluation was performed on the optical laminate.
The results are shown in Table 1.

[Example 4]
The distances from the apex of the corner of the raw material laminate (raw material laminate after polishing the end faces corresponding to the four sides) to the first notch start point P1 and the second notch start point P2 were set to 0.1 mm, respectively. An optical laminate was obtained in the same manner as in Example 2 except for the above. Peeling evaluation was performed on the optical laminate.
The results are shown in Table 1.

[Example 5]
(Preparation of raw material laminate)
Use a COP film having a thickness of 16 μm (hereinafter, sometimes referred to as “16HC-COP film”) on which a hard coat (HC) layer as a protective layer is formed, and do not attach a TAC film as a protective layer. A polarizing plate (2) with a surface protective film was obtained in the same procedure as in Example 1 except for the above. The polarizing plate with a surface protective film (2) is formed by laminating a surface protective film (polyester resin film, acrylic pressure-sensitive adhesive layer), a 16HC-COP film (HC layer, COP film), and a linearly polarizing layer in this order. there were.

A pressure-sensitive adhesive layer (2) with a release film was prepared by forming a pressure-sensitive adhesive layer (thickness 10 μm) formed on a release film (thickness 38 μm) using an acrylic pressure-sensitive adhesive. A polarizing plate with a surface protective film (2) is used instead of the polarizing plate with a surface protective film (1), and the linearly polarizing layer side of the polarizing plate with a surface protective film (2) and the λ / 4 plate of the retardation layer are separated. It is bonded by a bonding layer (thickness 5 μm) which is a pressure-sensitive adhesive layer, and the pressure-sensitive adhesive layer (2) with a release film is adhered to the positive C plate side of the retardation layer instead of the pressure-sensitive adhesive layer (1) with a release film. A raw material laminate (2) was obtained in the same procedure as in Example 1 except that the agent layers were bonded together.

The raw material laminate (2) is a polarizing plate with a surface protective film (2) (surface protective film, 16HC-COP film, linear polarizing layer), a bonding layer which is an adhesive layer, a retardation layer (λ / 4 plate,). The bonding layer, the positive C plate), and the pressure-sensitive adhesive layer (2) with a release film (the pressure-sensitive adhesive layer and the release film) were laminated in this order. The thickness of the laminated portion from the polarizing plate (16HC-COP film, linearly polarized light layer) to the retardation layer (λ / 4 plate, bonded layer, positive C plate) in the raw material laminate (2) was 36 μm. Further, the direction of the long side of the raw material laminate (2) was parallel to the absorption axis of the linearly polarized light layer.

(Preparation of optical laminate)
Using the raw material laminate (2), optical lamination was performed in the same procedure as in Example 2 except that the relative movement speed between the laminate W and the rotary tool 60 was 700 mm / min and the rotation speed of the rotary tool 60 was 4800 rpm. I got a body. Adhesion between the surface protective film and the release tape and the adhesion between the acrylic pressure-sensitive adhesive layer side of the surface protection film and the HC layer side of the 16HC-COP film in the same procedure as in Example 1. Was measured and found to be 9N / 25mm and 0.03N / 25mm, respectively.

[Example 6]
Optical lamination is performed in the same procedure as in Example 5 except that only one corner portion at one end of one short side of the raw material laminate (2) is polished to form one notch portion. I got a body. Peeling 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 notches were not formed. Peeling evaluation was performed on the optical laminate. 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 notches were not formed. Peeling evaluation was performed on the optical laminate. The results are shown in Table 1.

In each Example and each Comparative Example, each layer (25HC-COP film or 16HC-COP film, linearly polarized light layer, TAC film, adhesive layer, λ / 4 plate, pasted) constituting the optical laminate was applied at the time of the peeling test. No peeling was observed between the laminated layer, the positive C plate, the adhesive layer) and the glass plate (holding table).

1,1a, 1b optical laminate, 10a, 10b, 10c, 10d side, 10eb, 10ed line, 11b, 11d notch, 15 quadrangle, 15a first side, 15b second side, 15c third side, 15d first 4 sides, 20 polarized laminates, 21 polarizing plates, 22 retardation layers, 31 adhesive layers, 32 release films, 35 release tapes, 41 surface protection films, 50 supports, 51 substrates, 52 frames, 53 rotary tables , 54 Cylinder, 55 Jig, 60 Rotating Tool, Laa, Lab, Lba, Lbd Distance, Pab, Pda Vertex, P1b, P1d (P1) 1st Notch Start Point, P2b, P2d (P2) 2nd Notch Start Point , W Laminate.

Claims

An optical laminate including a surface protective film, a polarizing laminate containing a polarizing plate having a protective layer on one or both sides of a linear polarizing layer, and an adhesive layer in this order.
The surface protective film is provided so as to be peelable from the polarizing laminate.
The thickness of the polarizing laminate is 120 μm or less, and the thickness is 120 μm or less.
The plan view shape of the optical laminate is a shape in which one corner portion of the quadrangle has at least one notched portion.
The notch portion is along a notch line passing through a first notch start point P1 and a second notch start point P2 set on the first side and the second side forming the apex of the corner portion, respectively. Has a notched shape,
An optical laminate in which the first notch start point P1 and the second notch start point P2 are set so that the distances from the vertices are 0.1 mm or more and 0.5 mm or less, respectively.
The optical laminate according to 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 arcuate curve.
The optical laminate according to any one of claims 1 to 3, wherein the end surface of the optical laminate in the notch is a surface cut by a rotary tool.
The optical laminate according to any one of claims 1 to 4, wherein the lengths of the four sides of the quadrangle are each within a range of 30 mm or more and 100 mm or less.
It has at least two notches
The optical laminate according to any one of claims 1 to 5, wherein the cutout portion is provided so as to cut out two adjacent corner portions of the quadrangle.
The optical laminate according to any one of claims 1 to 6, wherein the polarizing laminate has a retardation layer on one side or both sides of the polarizing plate.
The optical laminate according to any one of claims 1 to 7, further comprising a release film that can be peeled off from the pressure-sensitive adhesive layer on the side of the pressure-sensitive adhesive layer opposite to the polarizing laminate side.
A peeling method for peeling the surface protective film from the optical laminate according to any one of claims 1 to 8.
The step of adhering the optical laminate to the adherend by the pressure-sensitive adhesive layer, and
A step of attaching a peeling tape to the surface of the optical laminate on the surface protective film side,
A step of peeling the surface protective film from the optical laminate attached to the adherend by causing the peeling tape is included.
The attachment step is a peeling method in which the peeling tape is attached so as to straddle one side provided with the notch at the end in the plan view shape of the optical laminate.
The optical laminate is the optical laminate according to claim 6.
The peeling method according to claim 9, wherein the one side on which the peeling tape is attached is a side provided with the notches at both ends.