TW202138192A - Optical laminate and pealing method - Google Patents

Abstract

This invention provides an optical laminate and a peeling method capable of properly peeling off a surface protective film.

The optical laminate of this invention includes a surface protective film, a polarizing laminate contains a polarizing plate with protective layer on a single surface or both surfaces of a linear polarizing layer, and a pressure sensitive adhesive layer in this order. The surface protective film is detachably from the polarizing laminate, and the thickness of the polarizing laminate is 120μm or less. The planar view shape of the optical laminate is a shape having at least one notch part that is cut-off from one corner of a quadrilateral, and the notch part has a shape obtained by being cut-off along a cut-off line passing through a first cut-off starting point P1 and a second cut-off starting point 2 provided on a first edge and a second edge constructing the vertex of the corner, respectively. The first cut-off starting point P1 and the second cut-off starting point 2 are provided so as to have a distance of 0.1 mm or more and 0.5 mm or less from the vertex.

Description

Optical laminate and peeling method

This invention relates to the peeling method of an optical laminated body and a surface protection film.

Polarizing plates are widely used as elements for supplying polarized light and elements for detecting polarized light in display devices such as liquid crystal display devices or organic electroluminescence (EL) display devices. In the past, a polarizer is used with a protective film attached to one or both sides of the polarizer.

In this type of polarizer, in order to prevent dirt or damage on its surface, a peelable surface protective film (also called "protective film") is provided on one surface of the polarizer, and an adhesive layer is provided on the other surface. (Pressure sensitive adhesive layer, also called pressure sensitive adhesive layer) and release film (also called "separation film") (for example, Patent Document 1, etc.) are distributed in the market. For example, the surface protection film is peeled and removed after attaching a polarizing plate to a member such as an image display element, and the peeling film is peeled and removed when, for example, the polarizing plate is installed on a member such as an image display element of a display device.

[Prior Technical Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Application Publication No. 2019-191551

Used in small polarizers such as smart phones and smart watches, sometimes a peeling tape is placed on one side of the surface protection film, and the surface protection film is peeled off by grabbing the peeling tape and pulling it up. . When the peeling tape is pulled up by such a peeling method, the peeling tape may peel from the surface protective film, and the surface protective film may not be peeled from the polarizing plate.

The object of the present invention is to provide an optical laminate that can peel a surface protective film well, and a peeling method.

The present invention provides the following optical laminate and peeling method.

[1] An optical laminate comprising a surface protective film, a polarizing laminate, and an adhesive layer in this order, the polarizing laminate including a polarizing plate having a protective layer on one or both sides of a linear polarizing layer, wherein,

The surface protection film is provided so as to be peelable with respect to the polarizing laminate,

The thickness of the aforementioned polarizing laminate is 120 μm or less,

The planar shape of the aforementioned optical laminate is a shape having at least one notch, and the notch is obtained by cutting off one corner of the quadrilateral,

The notch has a shape cut along a cutting line that passes through a first cutting start point P1 and a second cutting start point P2 respectively provided on the first side and the second side that constitute the vertex of the corner. ,

The first resection starting point P1 and the second resection starting point P2 are set to be 0.1 mm or more and 0.5 mm or less from the apex.

[2] The optical laminate according to [1], wherein the quadrilateral is a square.

[3] The optical laminate according to [1] or [2], wherein the cutting line is a straight line or an arc-shaped curve.

[4] The optical laminate according to any one of [1] to [3], wherein the end surface in the notch portion of the optical laminate is a cutting surface formed by a rotating tool.

[5] The optical laminate according to any one of [1] to [4], wherein the lengths of the four sides of the aforementioned quadrilateral are in the range of 30 mm or more and 100 mm or less.

[6] The optical laminate according to any one of [1] to [5], which has at least two notches described above,

The notch is provided in such a manner that two adjacent corners of the quadrilateral are cut off, respectively.

[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 laminate according to any one of [1] to [7], wherein the adhesive layer has an opposite side to the polarizing laminate side with respect to the adhesive layer. Peelable release film.

[9] A peeling method for peeling the aforementioned surface protective film from the optical laminate according to any one of [1] to [8], comprising:

In the bonding step, the optical laminate is bonded to the adherend through the adhesive layer;

A setting step of setting a peeling tape on the surface of the optical laminate on the side of the surface protection film; and

In the peeling step, the surface protection film is peeled off from the optical laminate that has been attached to the adherend by pulling up the peeling tape;

However, in the installation step, the peeling tape is installed so as to straddle one side where the notch is provided at the end of the optical laminate in the plan view shape.

[10] The peeling method according to [9], wherein the optical laminate is the optical laminate according to [6],

The one side where the peeling tape is to be provided is the side provided with the notch at both ends.

According to the present invention, it is possible to provide an optical laminate that can peel off a surface protective film satisfactorily.

1,1a,1b: optical laminate

10a, 10b, 10c, 10d: side

10eb, 10ed: line

11b, 11d: Notch

15: Quadrilateral

15a: side 1

15b: Side 2

15c: side 3

15d: 4th side

20: Polarizing laminated body

21: Polarizing plate

22: retardation layer

31: Adhesive layer

32: peeling film

35: Stripping tape

41: Surface protective film

45: Image display component

50: Support

51: substrate

52: Frame

53: Rotating table

54: Cylinder

55: Fixture

60: Rotation tool

Laa, Lab, Lba, Lbd: distance

Pab, Pda: Vertex

P1b, P1d (P1): the first resection starting point

P2b, P2d (P2): starting point of the second resection

α, β: shortest distance

W: buildup

Fig. 1 is a schematic plan view schematically showing an example of the optical laminate of the present invention.

Fig. 2 is an x-x' cross-sectional view of the optical laminate shown in Fig. 1.

Fig. 3 is a schematic plan view schematically showing an example of the step of peeling the surface protective film from the optical laminate of the present invention.

Fig. 4 is a schematic plan view schematically showing another example of the optical laminate of the present invention.

Fig. 5 is a schematic cross-sectional view schematically showing still another example of the optical laminate of the present invention.

Fig. 6 is a schematic cross-sectional view schematically showing still another example of the optical laminate of the present invention.

Fig. 7 is a schematic cross-sectional view schematically showing an example of the step of peeling the surface protective film from the optical laminate of the present invention.

Fig. 8 is a schematic perspective view schematically showing an example of the method of manufacturing the optical laminate of the present 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 the following drawings are used to help understand the present invention, and the size and shape of each constituent element shown in the drawings may not be consistent with the size and shape of the actual constituent elements.

(Optical laminate)

FIG. 1 is a schematic plan view schematically showing an example of the optical laminate of this embodiment. Fig. 1 shows a schematic plan view as viewed from the surface protection film side of the optical laminate. Fig. 2 is an x-x' cross-sectional view of the optical laminate shown in Fig. 1.

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

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

The top view shape of the resection line 10eb passing through the first resection starting point P1b and the second resection starting point P2b is not particularly limited. The cutting line 10eb may be a straight line as shown in FIG. 1, or an arc-shaped curve, for example. When the cut line 10eb is an arc-shaped curve, the cut line 10eb is preferably convex toward the vertex Pab of the corner of the quadrilateral 15.

The length of the cutting 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 cut line 10eb is preferably set in the following manner. In the planar shape of the optical layered body 1a, when the cutting line 10eb is along the direction from the first cutting start point P1b to the second cutting start point P2b, it is preferably such that it is aligned with the first cutting start point P2b. The cut-off line 10eb is set so that the shortest distance α of the first side 15a where the point P1b is located continuously increases, or that includes a fixed section including α and gradually increases the shortest distance. Moreover, in the plan shape of the optical layered body 1a, in the case where the cutting line 10eb is along the direction from the first cutting starting point P1b side to the second cutting starting point P2b, it is preferably such that it is aligned with the second cutting starting point P2b. The shortest distance β of the second side 15b where the resection starting point P2b is located continuously decreases, or the shortest distance β is included in a fixed section and the shortest distance β is gradually reduced. The resection line 10eb is set.

The quadrilateral 15 is a virtual top-view shape, and is set to include the sides of the top-view shape of the optical laminate 1a. The quadrilateral 15 is a rectangle having a first side 15a, a second side 15b, a third side 15c, and a fourth side 15d as shown in FIG. 1, for example. Part of the first side 15a and the second side 15b of the quadrilateral 15 shown in FIG. 1 respectively constitute the side 10a and the side 10b in the planar shape of the optical laminate 1a, and the third side 15c and the second side 15c and the second side of the quadrilateral 15 The four sides 15d as a whole respectively constitute a side 10c and a side 10d in the planar shape of the optical laminate 1a.

In the planar shape of the optical laminate 1a, the side 10a is the part of the first side 15a of the quadrilateral 15 that is opposite to the side from the first resection starting point P1b to the vertex Pab, and the side 10b is the second side of the quadrilateral 15 The part of the side 15b on the opposite side to the side from the second resection starting point P2b to the vertex Pab.

In this manner, the quadrilateral 15 set corresponding to the plan view shape of the optical laminate 1a is a quadrilateral having the side 10a and the side 10b in the plan view shape of the optical laminate 1a extended, and the intersection of the extensions of the two sides is included as the vertex Pab. In addition, when the quadrilateral 15 is set from the planar shape of the optical laminate 1a, the side extended from the planar shape of the optical laminate 1a is assumed to be obtained by cutting off the corners of the quadrilateral 15 to obtain the optical laminate 1a. The area cut by the quadrilateral 15 becomes the smallest mode setter.

The distance Laa from the vertex Pab to the first resection starting point P1b and the distance Lab from the vertex Pab to the second resection starting point P2b are each independently 0.1 mm or more, may be 0.2 mm or more, or may be 0.3 mm or more, It is 0.5 mm or less, or 0.4 mm or less. The distance Laa and the distance Lab may be the same or different from each other. As described later, when the peeling tape 35 (FIG. 3) is provided on the side 10a and the surface protection film 41 is peeled off, it is preferable that the distance Laa is greater than the distance Lab. If the distance Laa and the distance Lab are less than 0.1 mm, it will tend to be difficult to peel off the surface protective film 41 well. If the distance Laa and the distance Lab exceed 0.5 mm, when the optical laminate 1a is bonded to the image display element of the display device, the effective area tends to be smaller, and the image display area in the display device tends to be narrow.

Assuming that the cutting line formed by connecting the first cutting start point P1b and the second cutting start point P2b is a straight line, and the area of the part cut from the quadrilateral 15 in a plan view is set to S1, the optical laminate The area Sa of the part cut off from the quadrilateral 15 by the cutting line 10eb that 1a actually has in a plan view is preferably 0.6 times or more of the area S1, or 0.7 times The above may be 0.9 times or more, 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 the step of peeling the surface protective film from the optical laminate of the present embodiment. Since the optical layered body 1a has the notch part 11b, as shown in FIG. 3, the surface protection film 41 can be peeled favorably using the tape 35 for peeling. The method of peeling the surface protective film 41 using the peeling tape 35 will be described in detail later, but the surface protective film 41 can be peeled from the optical laminate 1a in the following manner, for example. First, as shown in FIG. 3, on the surface of the optical laminate 1a on the surface protection film 41 side, one end of the peeling tape 35 (hereinafter sometimes referred to as the "installation end" Department"). Then, the end on the side opposite to the installation end of the peeling tape 35 is pulled up, and the peeling tape 35 is torn off from the side 10a to the side 10c (the arrow direction in FIG. 3). Thereby, the surface protection film 41 can be peeled from the optical laminated body 1a. In the optical layered body 1a, a notch 11b is provided at the end of the side 10a on which the peeling tape 35 is to be provided. Thereby, compared with the case where the side 10a is not provided with the notch 11b, it is believed that the surface protection film 41 becomes easier to tear up when the peeling tape 35 is torn off. Therefore, in the optical layered body 1a, the peeling tape 35 can be suppressed from peeling off the surface protective film 41, and the surface protective film 41 can be peeled favorably by the peeling tape 35.

Fig. 4 is a schematic plan view schematically showing another example of the optical laminate of the present embodiment. Although the optical laminate 1a shown in FIG. 1 illustrates a case where there is one notch 11b, for example, the optical laminate 1b shown in FIG. 4 may have two notches, or may have three or four. Notch.

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

The top view shape of the resection line 10ed passing through the first resection starting point P1d and the second resection starting point P2d is not particularly limited. The excision line 10ed is the same as the excision line 10eb, and can be a straight line or an arc-shaped curve. When the cutting line 10ed is an arc-shaped curve, the cutting line 10ed preferably protrudes toward the vertex Pda of the corner of the quadrilateral 15. The preferred range of the length of the cut line 10ed is the same as the range described in the cut line 10eb.

The shape of the cut line 10ed is preferably set in the following manner. In the planar shape of the optical layered body 1b, when the cutting line 10ed is along the direction from the first cutting start point P1d side to the second cutting starting point P2d, it is preferably such that it rises from the first cutting start point P2d. The cutting line 10ed is set in a manner in which the shortest distance of the first side 15a where the starting point P1d is located continuously increases, or in a manner in which the shortest distance is fixed and the shortest distance is gradually increased. Moreover, in the plan shape of the optical layered body 1b, in the case where the cutting line 10ed is directed along the first cutting start point P1d side toward the second cutting start point P2d, it is preferable to make the cutting line 10ed and the second cutting start point P2d. The cut line 10ed is set in a manner in which the shortest distance of the fourth side 15d where the starting point P2d is located is continuously reduced, or in a manner including a section in which the shortest distance is fixed and the shortest distance is gradually reduced.

The quadrilateral 15 set corresponding to the top view shape of the optical laminate 1b is the same as the optical laminate 1a described above, and is a virtual top view shape, and is set to include the sides of the top view shape of the optical laminate 1b. Part of the first side 15a, the second side 15b, and the fourth side 15d of the quadrilateral 15 shown in FIG. 4 respectively constitute the side 10a, the side 10b, and the side 10d in the planar shape of the optical laminate 1b. The third side 15c provided as a whole constitutes the side 10c in the planar shape of the optical layered body 1b. In the top view shape of the optical laminate 1b, the side 10a is the line segment between the first resection starting point P1b and the first resection starting point P1d among the first side 15a of the quadrilateral 15, and the side 10b is the second side of the quadrilateral 15 The part of the side 15b opposite to the side from the second resection starting point P2b to the vertex Pab, and the side 10d is the fourth side 15d of the quadrilateral 15 and between the second resection starting point P2d toward the vertex Pda One side is the opposite side.

The quadrilateral 15 includes an intersection formed by extending the side 10a and the side 10b in the plan view shape of the optical laminate 1b as a vertex Pab, and includes an intersection formed by extending the side 10d and the side 10a as a vertex Pda. In addition, as in the case of the optical laminate 1a, assuming that the corners of the quadrilateral 15 are cut to obtain the optical laminate 1b, the area of the quadrilateral 15 is set to minimize the area from the optical laminate. When the planar shape of 1b is a quadrilateral 15, the sides extending from the planar shape of the optical layered body 1b are set. In addition, the shape of the quadrilateral set corresponding to the optical laminate 1b is set so that the two corners of the quadrilateral are cut to obtain the optical laminate 1b.

Assuming that the cutting line formed by connecting the first cutting start point P1d and the second cutting start point P2d is a straight line, and the area of the part cut from the quadrilateral 15 in a plan view is set to S2, the optical laminate 1b The area Sb of the part cut from the quadrilateral 15 by the actual cutting line 10ed in the plan view is preferably 0.6 times or more of the area S2, or 0.7 times The above may be 0.9 times or more, more preferably 1.6 times or less, 1.4 times or less, or 1.2 times or less.

In the optical layered body 1b, adjacent corners of the quadrilateral 15 form a notch 11b and a notch 11d. Therefore, it is considered that the force required to pull up the surface protective film 41 using the peeling tape 35 in the above-mentioned procedure is smaller than that in the case of peeling the surface protective film 41 in the optical laminate 1a, and the surface protective film 41 becomes easy to pull up. Thereby, in the optical laminated body 1b, the surface protective film 41 can be peeled more favorably by the tape 35 for peeling.

Although an optical laminate having one or two notches is taken as an example for description above, a quadrilateral may be set similarly to the above in accordance with the top view shape of an optical laminate having three or four notches. In addition, when the optical laminate has two or more notches, the shape of the quadrilateral is set as follows: assuming that the corners of the quadrilateral and the number of notches of the optical laminate are cut out , An optical laminate with this number of notches will 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, it is preferable to use the notches 11b, 11d of the optical laminate 1b as shown in FIG. At least 2 notches are provided in a way of cutting off the corners.

The optical layered bodies 1a and 1b (hereinafter sometimes referred to as "optical layered body 1" including both) may have a notch shape that is cut out into a shape different from the notch portion as long as it has the notch described above. For example, in the optical laminate 1, in addition to the notch described above, it is also possible to have the corners of the quadrilateral 15 by passing through a line of two points outside the length range described by the distances Laa, Lab, Lba, and Lbd. The shape of the cut-away notch.

The end surface (end surface in the lamination direction) in the notch 11 of the optical laminate 1 is preferably a cut surface formed by a rotary tool. In the case where the above-mentioned end surface is a cutting surface formed by a rotating tool, the surface protective film 41 and the end surface of the polarizing layered body 20 included in the optical laminate 1 are slightly deformed in accordance with the rotation direction of the rotating tool. This deformed state means that the end portions of the surface protection film 41 and the polarizing laminate 20 are not parallel to the plane direction of the optical laminate 1 but slightly warped or sag in the laminate direction. By generating the above-mentioned deformation on the end face of the optical layered body 1a, the surface protective film 41 can be peeled off more satisfactorily.

The quadrilateral 15 set corresponding to the planar shape of the optical laminate 1 is preferably a square. In this specification, a square refers to a quadrilateral with four vertices at right angles (internal angles of 90°), and specifically refers to a square or a rectangle. The quadrilateral 15 is more preferably a rectangle.

The lengths of the four sides of the quadrilateral 15 are independent, preferably 30 mm or more, preferably 40 mm or more, 50 mm or more, 140 mm or more, or 150 mm or more. In addition, it is preferably 200 mm or less, may be 190 mm or less, may be 180 mm or less, may be 80 mm or less, or may be 70 mm or less.

The surface protection film 41 is a film that is peelable with respect to the polarizing layered body 20, and it is preferable to be in a form in which it is in direct contact with the polarizing layered body 20. The surface protection film 41 is also referred to as a protective film. During the manufacturing steps of the optical laminate 1a and the manufacturing steps of the display device applied to the optical laminate 1a, it covers and protects the surface of the polarizing laminate 20, thereby suppressing this Dirt or damage on the surface. For example, after the optical laminate 1 is bonded to an adherend such as an image display element of a display device through the adhesive layer 31, the surface protective film 41 can be peeled off and removed.

The polarizing laminate 20 includes a polarizing plate 21 having a protective layer on one side or both sides of a linear polarizing layer. The thickness of the polarizing layered body 20 is preferably 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, or may be 20 μm or less Above, it may be 40 μm or more, or 50 μm or more. When the end surface processing such as polishing is performed in the manufacturing process of the optical layered body 1, the adhesive constituting the adhesive layer 31 oozes out to cover the end surface of the optical layered body 1, and the adhesive may reach the end surface of the surface protective film 41. In this case, it is recognized that the surface protective film 41 is fixed to the adhesive layer 31 due to the adhesive covering the end surface of the optical layered body 1, so that the surface protective film 41 is not easily peeled off from the optical layered body 1. It is believed that the smaller the thickness of the polarizing layered body 20, the smaller the distance between the surface protective film 41 and the adhesive layer 31 in the layering direction of the optical layered body 1, so that the end surface of the adhesive-coated optical layered body 1 is likely to be surface protected The film 41 is not easily peeled off. As described above, the optical layered body 1 has the notches 11b and 11d. Therefore, even when the thickness of the polarizing laminate 20 is small, the surface protective film 41 can be peeled off well.

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

Fig. 5 is a schematic cross-sectional view schematically showing still another example of the optical laminate of the present embodiment.

The optical laminated system shown in FIG. 5 shows an example of the case where the polarizing laminated body 20 is a laminated body of the polarizing plate 21 and the retardation layer 22. The polarizing plate 21 and the retardation layer 22 may be laminated via a bonding layer such as an adhesive layer or an adhesive hardening layer. When the polarizing layered body 20 has the retardation layer 22, the retardation layer 22 may 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, or only one side of the polarizing plate 21 may be provided Two or more retardation layers 22. The retardation layer is not particularly limited, and examples include: 1/2 wavelength retardation layer, 1/4 wavelength retardation layer, reverse wavelength dispersion 1/4 wavelength retardation layer, positive C plate, etc. .

When the retardation layer 22 has a slow axis in the plane, the slow axis may be parallel (0°) with respect to the absorption axis of the polarizer, or may have an angle exceeding 0°. For example, the slow axis of the retardation layer 22 may also have an angle of 15°, 30°, 45°, 60°, 75° or 90° with respect to the absorption axis of the polarizer.

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

The adhesive layer 31 can be used to bond the optical laminate 1 to an adherend such as an image display element of a display device. The adhesive layer 31 is preferably provided in such a way as to directly contact the polarizing laminate 20. In the polarizing laminate 20, when the adhesive layer is used for bonding a polarizing plate and an optical function layer and/or bonding retardation layers to each other, the adhesive layer 31 is positioned in the laminate direction of the optical laminate 1. The adhesive layer at the position farthest from the surface protective film 41 in the middle.

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 1 a may further have a release film 32 that can be peeled from the adhesive layer 31 on the side opposite to the polarizing laminate 20 in the adhesive layer 31. The peeling film 32 is usually provided in such a way that it directly contacts the adhesive layer 31. The peeling film 32 is also called a separation film, which is used to cover and protect the surface of the adhesive layer 31 to prevent foreign matter and the like from adhering to the adhesive layer 31. When the optical laminate 1 is bonded to an adherend such as an image display element of a display device via the adhesive layer 31, the release film 32 can be peeled and removed.

The optical laminate 1 can be used in display devices such as smart phones or smart watches. Examples of the display device include a liquid crystal display device, an organic EL (electroluminescence) display device, and the like. After the optical layered body 1 is bonded to an adherend such as an image display element of a display device via the adhesive layer 31, the surface protective film 41 is peeled off. Thereby, the polarizing laminated body 20 included in the optical laminated body 1 can be assembled in a display device.

(Method of manufacturing optical laminate)

For example, a laminate having a surface protective film, a polarizing laminate, an adhesive layer, and a release film in this order can be cut into a predetermined shape and size to form a raw laminate, and then a notch can be formed to produce an optical laminate Body 1. As a method of forming a notch for the raw material laminate, for example, a method of polishing the end surface (end surface parallel to the lamination direction) of the raw material laminate, the use of a Thomson blade, a laser cutter, etc. One or two or more of them are combined to separate the laminates of raw materials. Among them, in order to suppress the occurrence of burrs or the like on the end surface of the optical layered body 1 in the layering direction, and to obtain good dimensional accuracy of the optical layered body 1, it is preferable to form the notch by polishing. The above-mentioned grinding or cutting may be carried out for one sheet of raw material layered body, or two or more sheets of raw material may be layered together in bulk.

The shape of the raw material laminate in plan view may be selected in accordance with the shape of the optical laminate 1, and is not particularly limited. When the notch is formed by polishing, the top view shape of the raw material laminate is preferably a quadrilateral 15 (FIG. 1 and FIG. 4) set in accordance with the top view shape of the optical laminate 1 described above, more preferably a square, even more preferably It is rectangular. By making the planar shape of the raw material laminate to be the quadrilateral 15 described above, the area where the raw material laminate is cut can be reduced.

In the case of manufacturing the optical laminate 1 from the raw material laminate having the planar shape of the quadrilateral 15 described in FIGS. 1 and 4, the corners of the quadrilateral 15 are cut to include the apex Pab and/or the apex Pda by polishing. The notches 11b and 11d may be formed in the shape of a right-angled triangle (for example, an isosceles right-angled triangle).

FIG. 8 is a schematic perspective view schematically showing an example of the method of manufacturing the optical laminate of the present embodiment.

The method of manufacturing the optical layered body 1 from the raw material layered body by grinding may include, for example, the following steps:

[a] In the first step, a plurality of laminates of raw materials are stacked to obtain a laminate W;

[b] In the second step, in a direction parallel to the end face of the laminate W, that is, in a direction orthogonal to the laminate direction, a rotary tool 60 having a cutting edge rotating around the rotation axis R is opposed to the laminate W By moving, the end surface of the laminate W is cut.

In the method of manufacturing the optical layered body 1, for example, after the first step (above [a]) is performed, the 4 sides of the raw material layered body having a quadrangular plan view shape is first polished in the second step ([b] above), and then The second step (above [b]) is polished to the corners of the quadrilateral to form a notch.

The first step is a step of stacking a plurality of laminates of raw materials cut into a predetermined shape to obtain a laminate W. The number of sheets of the raw material layered body contained in the layered product W is not particularly limited, but the layered product W may be, for example, a volume layer of 100 to 500 sheets of raw material. For example, the raw material laminated body may be cut out from the elongated laminated body which has the layer structure of a raw material laminated body.

The second step is a step of cutting the end surface of the laminate W obtained in the first step by the rotary tool 60, and then forming a cutting surface on the end surface in the notch portion of the optical laminate 1 to form the optical laminate 1 .

The cutting process performed in the second step, for example, as shown in FIG. The support part 50 presses the laminate W from the top and bottom to fix it during the cutting process to prevent the laminate W from moving and dislocation of the stacked raw material laminate. The rotating tool 60 is used for cutting the end surface of the laminate W, and is capable of rotating around the rotation axis R.

The supporting part 50 may include: a flat substrate (a means for moving the laminate W) 51; a gate-shaped frame 52 arranged on the substrate 51; and a rotating table 53 arranged on the substrate 51 and can be centered The spindle rotates around the center; and a cyliner 54 that can move up and down is provided in the frame 52 at a position opposite to the rotating table 53. The laminate W is clamped and fixed by the rotating table 53 and the cylinder 54 through the clamp 55.

The rotating tool 60 has a disk-shaped rotating body that rotates around the rotating shaft R. The direction of rotation of the rotating body is the direction indicated by the arrow in FIG. 8. On the disk surface of the rotating body (the surface facing the end surface of the laminate W, that is, the surface parallel to the end surface), a plurality of (for example, 2 to 10, preferably 3 to 7) cutting edges. Preferably, the rotation axis R is set to pass through the center of the disk surface of the rotating body. The cutting edge is provided so as to protrude from the disk surface of the rotating body toward the end surface side of the laminate W. When the cutting edge abuts on the end surface of the laminate W, the rotating body rotates around the rotation axis R, thereby enabling The end face of the laminate W is cut.

The two rotating tools 60 are provided on both sides of the base plate 51 so as to face each other. The rotating tool 60 can move in the direction of the rotation axis R according to the size of the laminate W, and the substrate 51 can move between the two rotating tools 60. During the cutting process, the laminate W is fixed to the support part 50, and the position of the rotary tool 60 in the direction of the rotation axis R is appropriately adjusted. On the one hand, the rotary tool 60 is rotated around the rotation axis R. The substrate 51 is moved so that the laminate W passes between a pair of rotating tools 60 facing each other. Thereby, the rotary tool 60 is moved relative to the laminate W in a direction parallel to the end surface of the laminate W, that is, in a direction orthogonal to the laminate direction, and the cutting edge of the rotary tool 60 is brought into contact with the laminate W The oppositely exposed end faces can be cut off by this.

The relative moving speed between the laminate W and the rotating 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). The rotation speed of the rotating tool 60 can be selected from, for example, The range of 2000 rpm or more and 8000 rpm or less (more typically, the range of 2500 rpm or more and 6000 rpm or less).

(How to peel off the surface protective film)

FIG. 7 is a schematic cross-sectional view schematically showing an example of the step of peeling the surface protective film from the optical laminate of the present embodiment. The peeling method of peeling the surface protective film 41 from the optical laminate 1 includes: bonding the optical laminate 1 to the image display element 45 (attachment) with the adhesive layer 31 (FIG. 7 ); applying the peeling tape 35 Step of installing on the surface of the optical laminate 1 on the surface protection film 41 side (FIG. 3, FIG. 7(a)); by pulling up the peeling tape 35, from the optical laminate bonded to the image display element 45 1 Step of peeling off the surface protection film 41 (FIG. 7(b) and (c)).

In the step of installing the peeling tape 35, the peeling tape 35 is provided so that one side of the notched portion 11b or the notched portion 11d is provided across the end portion in the planar shape of the optical layered body 1. Fig. 3 shows an example of the peeling tape 35 being placed across the side 10a, but it may also be a side with a notch 11b or 11d at the end (for example, the side 10b shown in Figs. 1 and 4, and the side 10b shown in Fig. 4). Side 10d). As shown in Figure 4, when the two ends of the side 10a are provided with notches 11b and 11d, by pulling up the peeling tape 35, the surface protection film 41 can be peeled off more satisfactorily. The peeling tape 35 is provided so as to pass the edge 10a. The peeling tape 35 is usually directly provided on the surface of the surface protection film 41.

When the optical laminate 1 has a release film 32 (FIG. 6 ), it is a step of bonding to the image display element 45 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 installing the peeling tape 35.

In the step of peeling off the surface protective film 41, in the peeling tape 35, hold the end provided on the side surface of the surface protective film 41, that is, the end on the side opposite to the provided end (hereinafter Sometimes called "grip side end"), it will peel off on the side opposite to the image display element 45 side (the direction of the upper right side in Fig. 7(a), the direction of the arrow in Fig. 7(a)) Pull up with tape 35. Fold the gripping side end of the peeling tape 35 toward the set end side (in the direction of the arrow in Figure 7(b)), and pull it toward the reverse direction (the direction of the arrow in Figure 7(c)) As a result, the surface protection film 41 can be peeled from the optical layered body 1 and the surface of the polarizing layered body 20 can be exposed.

The peeling of the surface protection film 41 can be performed manually, or can be performed automatically using a peeling device. In the case of using a peeling device, the gripping side end of the peeling tape 35 is placed on the chuck of the peeling device, and the chuck and the optical laminate 1 are moved relative to each other to pull up the peeling tape 35. The surface protection film 41 is peeled off.

As described above, in the planar shape of the optical layered body 1, the peeling tape 35 is provided on the side where the notch 11b and/or the notch 11d is provided at the end, so that the surface protection film 41 can be reduced using the peeling tape 35. Pull up the required force. Therefore, according to the peeling method of this embodiment, the surface protection film can be peeled off favorably compared with the case where the surface protection film is peeled from the optical laminated body which does not have a notch part. Especially when the optical laminate 1b shown in FIG. 4 has notched portions 11b and notched portions 11d at both ends of the side 10b, by providing the peeling tape 35 on the side 10b, the surface can be protected more satisfactorily The film 41 peels off.

Hereinafter, each member used in the peeling method of the optical layered body and the surface protective film of this embodiment is demonstrated in detail.

(Surface protection film)

The surface protection film is provided on the surface of the polarizing laminate. When the outermost surface of the polarizing laminate is a polarizing plate, the surface protection film is preferably provided on the polarizing plate. The surface protection film may be a resin film for a surface protection film with an adhesive layer formed thereon, or may be formed by a self-adhesive film alone. The thickness of the surface protection film may be, for example, 30 to 200 μm, preferably 30 to 150 μm, more preferably 30 to 120 μm.

Examples of the resin constituting the resin film for the surface protective film include: polyolefin resins such as polyethylene resins and polypropylene resins; cyclic polyolefin resins; polyethylene terephthalate or polynaphthalene Polyester resins such as ethylene dicarboxylate; polycarbonate resins; (meth)acrylic resins, etc. Among them, polyester resins such as polyethylene terephthalate are preferred. The resin film for surface protection films may have a single-layer structure or a multilayer structure having two or more layers. The resin film for a surface protection film may be a film subjected to stretching treatment such as uniaxial stretching or biaxial stretching.

The adhesion force (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 0.01N/25mm or more, or 0.03N/25mm or more, or 0.08N/25mm Above, it is preferably 0.5N/25mm or less, 0.4N/25mm or less, or 0.3N/25mm or less.

The above-mentioned adhesion force (Fp) can be measured by the following procedure. The optical laminate 1 was cut into a rectangle of 150 mm×25 mm, and then bonded to an alkali-free glass substrate (thickness 0.7 mm, "Eagle XG" manufactured by Corning Corporation) via the adhesive layer 31, as a test piece. Put this test piece into an autoclave with an internal temperature of 50°C and an internal pressure of 490.3kPa (gauge pressure) for 20 minutes and expose it to a heated and pressurized environment, then store it for 24 hours in an environment with a temperature of 23°C and a relative humidity of 55%RH , As a sample for evaluation. For this evaluation sample, according to JIS K6854-2: 1999 "Adhesive-Peeling Adhesive Strength Test Method-Part 2: 180° Peeling", using a peeling device (Shimadzu Corporation "Autograph AGS-50NX") to move A 180° peel test was performed at a speed of 300 mm/min, and the measured peel force was used as the adhesion force (Fp).

In the case where the surface protection film is a resin film for surface protection film provided with an adhesive layer, the thickness of the adhesive layer is preferably 5 μm or more, may also be 10 μm or more, or may be 15 μm or more, and more preferably 30 μm or less, may be 25 μm or less, or may be 20 μm or less.

The above-mentioned surface protection film can be obtained by applying an adhesive on the surface of the resin film for a surface protection film and drying it to form an adhesive layer. It can also be used for surface protection according to needs The coating surface of the adhesive of the resin film for a film is surface-treated (for example, corona treatment, etc.) to improve adhesion, and a thin layer such as a primer layer (also referred to as a primer layer) may be formed. In addition, when the surface protection film has an adhesive layer as required, it may also have 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 protection film. The peeling layer can be peeled off at an appropriate timing when it is going to be bonded to the polarizing laminate.

A self-adhesive film that can be used as a surface protective film is a film that does not have an adhesive layer or other means for attaching, but is attached by itself and can maintain its attached state. For example, polypropylene resin, polyethylene resin, etc. can be used to form a self-adhesive film.

(Polarizing laminated body)

The polarizing laminate includes at least a polarizing plate having a protective layer on one side or both sides of the linear polarizing layer. The polarizing laminate may include only a polarizing plate, or may include a polarizing plate and an optical function layer other than the polarizing plate. Examples of the optical functional layer include those described above. The optical function layer may be one layer or two or more layers. Between the linear polarizing layer and the protective layer, between the polarizing plate and the optical function layer, and between the optical function layer when two or more optical function layers are laminated, it can also be cured through an adhesive layer or adhesive Layers and other lamination layers are attached.

(Linear Polarizing Layer)

The linearly polarized layer has the property of allowing linearly polarized light having a vibration plane orthogonal to the absorption axis to pass through when unpolarized light is incident. The linear polarizing layer may be a resin film containing polyvinyl alcohol (hereinafter sometimes referred to as "PVA"), or a cured film formed by aligning a dichroic dye in a polymerizable liquid crystal compound and polymerizing a polymerizable liquid crystal compound .

Examples of the linear polarizing layer containing a PVA-based resin film include: PVA-based films, partially formalized PVA-based films, ethylene/vinyl acetate copolymer-based partially saponified films, and other hydrophilic polymer films that are iodine or two-color Dyeing places with dichroic substances such as dyes Processing, and extended processing. From the viewpoint of excellent optical properties, it is preferable to use a linearly polarizing layer obtained by dyeing a PVA-based resin film with iodine and performing uniaxial stretching.

PVA-based resins can be produced by saponifying polyvinyl acetate-based resins. The polyvinyl acetate-based resin may be a copolymer of vinyl acetate and other monomers that can be copolymerized to vinyl acetate in addition to polyvinyl acetate which is a single polymer of vinyl acetate. Examples of other monomers that can be copolymerized to 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 generally about 85 to 100 mol%, preferably 98 mol% or more. PVA-based resins may also be modified. For example, polyvinyl formaldehyde or polyvinyl acetal modified with aldehydes may also be used. The average degree of polymerization of the PVA-based resin is usually 1,000 to 10,000 or so, preferably 1,500 to 5,000 or so. The average degree of polymerization of the PVA-based resin can be determined in accordance with JIS K 6726 (1994). If the average degree of polymerization is less than 1,000, it is difficult to obtain better polarization performance, and if it exceeds 10,000, the film processability will deteriorate.

As another method of manufacturing a linear polarizing layer containing a PVA-based resin film, a method including the following steps can be cited: first, a substrate film is prepared, a solution of resin such as PVA-based resin is coated on the substrate film, and drying is performed to remove the solvent. Etc., and the step of forming a resin layer on the base film.

In addition, a primer layer may 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. As the material of the primer layer, a resin obtained by cross-linking a hydrophilic resin used in a linear polarizing layer, etc. may be mentioned.

Next, adjust the amount of solvent such as moisture in the resin layer according to the needs, and then uniaxially stretch the base film and the resin layer, and then dye the resin layer with a dichroic dye such as iodine so that the dichroic dye is adsorbed on the resin layer and oriented accordingly. It needs to be treated with boric acid aqueous solution to have two-color adsorption orientation The resin layer of the sex dye is then subjected to a washing step of washing off the boric acid aqueous solution. Thereby, it is possible to produce a film that adsorbs and oriented a resin layer having a dichroic dye, that is, a linear polarizing layer. Known methods can be used for each step.

The uniaxial stretching of the substrate film and the resin layer can also be carried out before dyeing, during dyeing, or during boric acid treatment after dyeing, or uniaxial stretching can be carried out separately in these plural stages. . The base film and resin layer can also be uniaxially stretched in the MD direction (film conveying direction). In this case, it can be uniaxially stretched between rollers with different peripheral speeds, or a heated roller can be used for uniaxial stretching. . In addition, the base film and the resin layer may be uniaxially stretched in the TD direction (direction perpendicular to the film conveying direction). In this case, the so-called tenter method can be used. In addition, the stretching of the base film and the resin layer may be dry stretching in the atmosphere, or wet stretching in a state where the resin layer is swelled with a solvent. In order to exhibit the performance of the linear polarizing layer, the stretching ratio is 4 times or more, preferably 5 times or more, and particularly preferably 5.5 times or more. The upper limit of the stretching ratio is not particularly limited, but it is preferably 8 times or less from the viewpoint of suppressing breakage or the like.

By laminating the protective layer described later, and peeling off the base film, the linearly polarizing layer produced by the above method can be obtained. According to this method, the linear polarizing layer can be further thinned.

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

As a method for producing a cured film formed by aligning a dichroic dye in a polymerizable liquid crystal compound and polymerizing the polymerizable liquid crystal compound, that is, a linear polarizing layer, there may be mentioned: coating a base film containing a polymerizable liquid crystal compound and a dichroic property The composition for forming a polarizing layer of a dye is a method of forming a linear polarizing layer by polymerizing and curing a polymerizable liquid crystal compound while maintaining it in a liquid crystal state. The linear polarizing layer obtained in this way is in the state of being laminated on the base film, and the base film can also be attached The linear polarizing layer of is used as a polarizing plate 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.

色素、花青色素、萘色素、偶氮色素、蒽醌色素等，其中較佳為偶氮色素。作為偶氮色素，可列舉：單偶氮色素、雙偶氮色素、參偶氮色素、肆偶氮色素、二苯乙烯偶氮色素等，更佳為雙偶氮色素、參偶氮色素。 As a dichroic dye, a dye having a property that the absorbance in the long axis direction of the molecule is different from the absorbance in the short axis direction 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 dichroic dyes include acridine dyes,

Pigments, cyanine pigments, naphthalene pigments, azo pigments, anthraquinone pigments, etc., of which azo pigments are preferred. Examples of azo dyes include monoazo dyes, bisazo dyes, ginsenochromes, tetrazo dyes, and stilbene azo dyes, and more preferably bisazo dyes and ginsenochromes.

The composition for forming a polarizing layer may contain a polymerization initiator such as a solvent and a photopolymerization initiator, a photosensitizer, a polymerization inhibitor, and the like. Regarding the polymerizable liquid crystal compound, dichroic dye, solvent, polymerization initiator, photosensitizer, polymerization inhibitor, etc. contained in the composition for forming a polarizing layer, known ones can be used. For example, Japanese Patent Application Publication No. 2017-102479 can be used. No. Bulletin and Japanese Patent Application Publication No. 2017-83843 exemplified. Moreover, as a polymerizable liquid crystal compound, the compound exemplified as a polymerizable liquid crystal compound for obtaining a cured material layer of a retardation layer mentioned later can also be used. Regarding the method of forming a linear polarizing layer using the composition for forming a polarizing layer, the method exemplified in the above publication can be adopted.

(Polarizer)

The linear polarizing layer can be used as a polarizing plate with a protective layer on one side or two areas. This polarizing plate is a so-called linear polarizing plate. As a protective layer that can be laminated on one or both sides of the linear polarizing layer, for example, a film formed of a thermoplastic resin excellent in transparency, mechanical strength, thermal stability, water resistance, isotropy, and extensibility can be used. Specific examples of such thermoplastic resins include: cellulose resins such as triacetyl cellulose; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polyether resins; poly Tungsten resin; polycarbonate resin; nylon or aromatic polyamide Polyamide resins such as amines; polyimide resins; polyolefin resins such as polyethylene, polypropylene, and ethylene/propylene copolymers; ring systems and cyclic polyolefin resins with a norbornene structure (also known as norbornene System resin); (meth)acrylic resin; polyarylate resin; polystyrene resin; polyvinyl alcohol resin, and mixtures thereof.

When the two-area layer of the linear polarizing layer has a protective layer, the resin composition of the two protective layers may be the same or different. In addition, in this specification, "(meth)acrylic acid" means either acrylic acid or methacrylic acid. "(Meth)" such as (meth)acrylate also has the same meaning.

The protective layer may have phase difference characteristics, or may have functional layers such as a hard coat layer or an anti-reflection layer. The thickness of the protective layer is preferably 3 μm or more, more preferably 5 μm or more. In addition, the thickness of the protective layer is preferably 50 μm or less, more preferably 30 μm or less. In addition, the above upper limit and lower limit can be arbitrarily combined.

(Retardation layer)

The polarizing layered body may include a retardation layer. The retardation layer may include a cured layer of a polymerizable liquid crystal compound, or may be a stretched resin film.

When the retardation layer includes a cured layer of a polymerizable liquid crystal compound, as the polymerizable liquid crystal compound, a rod-shaped polymerizable liquid crystal compound and a disc-shaped polymerizable liquid crystal compound can be used. One of these can be used, or A mixture containing these two types can be used. When the rod-shaped polymerizable liquid crystal compound is oriented horizontally or vertically with respect to the base layer, the optical axis of the polymerizable liquid crystal compound coincides with the direction of the long axis of the polymerizable liquid crystal compound. When the discotic polymerizable liquid crystal compound is oriented, the optical axis of the polymerizable liquid crystal compound exists in a direction orthogonal to the disc surface of the polymerizable liquid crystal compound. As the rod-shaped polymerizable liquid crystal compound, for example, compounds described in Japanese Patent Application Publication No. 11-513019 (claim 1 etc.) can be preferably used. As the disc-shaped polymerizable liquid crystal compound, Japanese Patent Application Publication Compounds described in 2007-108732 (paragraphs [0020] to [0067], etc.) and JP 2010-244038 (paragraphs [0013] to [0108], etc.).

In order to make the cured product layer formed by polymerizing the polymerizable liquid crystal compound exhibit an in-plane phase difference, it is only necessary to orient the polymerizable liquid crystal compound in an appropriate direction. When the polymerizable liquid crystal compound is in a rod shape, the optical axis of the polymerizable liquid crystal compound is horizontally oriented with respect to the plane of the substrate layer to exhibit an in-plane phase difference. In this case, the optical axis direction coincides with the slow axis direction. When the polymerizable liquid crystal compound is in the shape of a disc, the optical axis of the polymerizable liquid crystal compound is horizontally oriented with respect to the plane of the substrate layer to exhibit an in-plane phase difference. In this case, the optical axis is orthogonal to the slow axis. By the combination of the alignment layer and the polymerizable liquid crystal compound, the alignment state of the polymerizable liquid crystal compound can be adjusted.

The polymerizable liquid crystal compound is a compound having at least one polymerizable group and liquid crystallinity. When two or more types of polymerizable liquid crystal compounds are used in combination, it is preferable that at least one type has two or more polymerizable groups in the molecule. The polymerizable group refers to a group related to a polymerization reaction, and is preferably a photopolymerizable group. Here, the photopolymerizable group refers to a group related to a polymerization reaction due to a living radical or acid generated by a photopolymerization initiator described later. Examples of polymerizable groups include vinyl groups, vinyloxy groups, 1-chlorovinyl groups, isopropenyl groups, 4-vinylphenyl groups, acryloxy groups, methacryloxy groups, and ethylene oxide groups ( oxiranyl), oxetanyl, styryl, allyl, etc. Among them, propyleneoxy group, methacryloxy group, ethyleneoxy group, oxirane group and oxetanyl group are preferred, and propyleneoxy group is more preferred. The liquid crystallinity possessed by the polymerizable liquid crystal compound can be either a thermotropic liquid crystal or a lyotropic liquid crystal. If the thermotropic liquid crystal is classified according to the degree of order, it can be a nematic liquid crystal or a lamellar liquid crystal.

When the retardation layer includes a cured layer of a polymerizable liquid crystal compound, the retardation layer may include an alignment layer. The alignment layer has an alignment regulating force for aligning the polymerizable liquid crystal compound in a desired direction. The alignment layer may be such that the molecular axis of the polymerizable liquid crystal compound is perpendicular to the substrate layer. The vertical alignment layer may be a horizontal alignment layer in which the molecular axis of the polymerizable liquid crystal compound is horizontally aligned with respect to the base layer, or may be an oblique alignment layer in which the molecular axis of the polymerizable liquid crystal compound is obliquely aligned with respect to the base layer. The first alignment layer and the second alignment layer may be the same alignment layer or different alignment layers.

As the alignment layer, it is preferable to have solvent resistance that does not dissolve due to application of the composition for forming a liquid crystal layer or the like, and to have heat resistance to heat treatment to remove the solvent and the alignment of the polymerizable liquid crystal compound. Examples of the orientation layer include: an orientation polymer layer formed of an orientation polymer, a photo orientation polymer layer formed of a photo orientation polymer, and a layer having a concave-convex pattern or a plurality of grooves on the surface of the layer. Trench orientation layer.

The composition for forming a liquid crystal layer containing a polymerizable liquid crystal compound is coated on a base layer and dried to polymerize the polymerizable liquid crystal compound, thereby forming a cured layer of the polymerizable liquid crystal compound. The composition for forming a liquid crystal layer may be coated on the alignment layer formed on the substrate 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 for forming the protective layer. The thickness of the substrate layer is not particularly limited. Generally, from the viewpoint of workability such as strength and handleability, it is preferably 1 to 300 μm, more preferably 20 to 200 μm, and still more preferably 30 to 120 μm. The base material layer can be assembled as a retardation layer together with the cured product layer of the polymerizable liquid crystal compound into the polarizing laminate, or the base material layer can be peeled off and only the cured product layer of the polymerizable liquid crystal compound or the cured product layer And the alignment layer is assembled to the polarizing laminate as a retardation layer.

As the resin film used for the stretched resin film, a film made of a thermoplastic resin that can be used to form a protective layer can be cited. Examples of the stretching treatment include uniaxial stretching, biaxial stretching, and the like. The extending direction in the stretching process may be the longitudinal direction of the unstretched resin, may be a direction orthogonal to the longitudinal direction, or may be a direction diagonally intersecting with the longitudinal direction. Uniaxial extension In the case of, as long as the unstretched resin is stretched in any of these directions. The biaxial extension may be simultaneous biaxial extension while extending in two of these directions simultaneously, or it may be sequential biaxial extension in which extension is performed in a predetermined direction and then in other directions.

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

(Laminated layer)

Examples of the bonding layer for bonding the layers included in the polarizing laminate include an adhesive layer or an adhesive hardened layer. When the adhesive layer is an adhesive layer, the adhesive described in the adhesive layer 31 described later can be used to form the adhesive layer. The adhesion force of the adhesive layer as the bonding layer to the alkali-free glass substrate (thickness 0.7mm, Corning "Eagle XG") at a temperature of 23°C and a relative humidity of 55% is preferably 1N/25mm or more, It is 3N/25mm or more, may be 10N/25mm or more, more preferably 50N/25mm or less, may be 40N/25mm or less, or 30N/25mm or less. The adhesion force can be measured in accordance with JIS K 6854-2: 1999 "Adhesives-Peeling Adhesive Strength Test Method-Part 2: 180° Peeling". In addition, the adhesion force to adherends other than the alkali-free glass substrate (thickness 0.7mm, Corning Corporation "Eagle XG") can also be regarded as the same level as the adhesion force to the general alkali-free glass substrate.

The adhesive force (Fb) between the bonding layer which bonds each layer which comprises a polarizing laminated body, and each layer bonded to it is normally larger than the adhesive force (Fp) of the surface protection film 41 with respect to the polarizing laminated body 20, respectively. The difference between the adhesion force (Fb) and the adhesion force (Fp) is, for example, 0.1 N/25 mm or more, preferably 0.5 N/25 mm or more, and usually 50 N/25 mm or less. In addition, the adhesion force (Fa) of the later-mentioned adhesive layer 31 to the image display element 45 (attachment) is generally the same as the adhesion force (Fb), and is greater than the adhesion force (Fp) of the surface protective film 41 to the polarizing laminate 20. Adhesion force (Fa) and adhesion force (Fp) The difference between is, for example, 1N/25mm or more, preferably 3N/25mm or more, and usually 50N/25mm or less.

When the adhesion force (Fb) is less than the adhesion force (Fp), after the optical laminate 1 is bonded to the image display element 45 with the adhesive layer 31, when the surface protective film 41 is peeled off, the polarizing laminate may be formed The layers of 20 are peeled off from each other. In addition, when the adhesion force (Fa) is smaller than the adhesion force (Fp), after the optical laminate 1 is bonded to the image display element 45 via the adhesive layer 31, when the surface protective film 41 is peeled off, it may be removed from the adhesive layer The layer 31 and the image display element 45 peeled off.

The adhesion force (Fa) can be greater or less than the adhesion force (Fb), or the same. When the adhesion force (Fa) is smaller than the adhesion force (Fb), heavy work can be easily performed to peel off the polarizing laminate 20 bonded to the image display element 45 from the image display element 45 and then bond the new optical laminate 1 .

The storage elastic modulus of the adhesive layer as the bonding layer at a temperature of 80°C is preferably 0.01 MPa or more, or 0.02 MPa or more, and preferably 0.3 MPa or less, or 0.25 MPa or less, or 0.2 Below MPa. The above-mentioned storage elastic modulus can be punched into a cylindrical body with a diameter of 8mm by punching an adhesive layered body with a thickness of 0.2mm, which is made by laminating multiple layers of adhesives. It is used as a measurement sample according to JIS K7244-6. The viscoelasticity measuring device sold is measured under the following conditions.

Forward force FN: 1N

Strain γ: 1%

Frequency: 1Hz

Temperature: 80℃

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

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

Examples of the water-based adhesive include an adhesive obtained by dissolving or dispersing a polyvinyl alcohol-based resin in water. The drying method in the case of using a water-based adhesive is not particularly limited. For example, a method of drying using a hot air dryer or an infrared dryer can be adopted.

Examples of active energy ray curable adhesives 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. . By using a solvent-free active energy ray curable adhesive, the adhesion between layers can be improved.

As an active energy ray curable adhesive agent, it is preferable to contain any one or both of a cationically polymerizable curable compound and a radically polymerizable curable compound from the viewpoint of exhibiting good adhesiveness. The active energy ray curable adhesive may further include a cationic polymerization initiator or a radical polymerization initiator for initiating the curing reaction of the curable compound.

Examples of cationically polymerizable curable compounds include epoxy compounds (compounds having one or more epoxy groups in the molecule), oxetane compounds (one or two in the molecule). Compounds with more than one oxetane ring) or combinations thereof.

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

The active energy ray curable adhesive may contain a sensitizer according to demand. By using a sensitizer, the reactivity is improved, and the mechanical strength and adhesive strength of the hardened layer of the adhesive can be further improved. As the sensitizer, those known in the art can be suitably used. In the case of blending sensitizers, the blending amount It is preferably in the range of 0.1 to 20 parts by mass relative to 100 parts by mass of the total amount of the active energy ray curable adhesive.

Active energy ray curable adhesives can contain ion scavengers, antioxidants, chain transfer agents, tackifiers, thermoplastic resins, fillers, flow regulators, plasticizers, defoamers, antistatic agents, Additives such as levelling agent and solvent.

When an active energy ray curable adhesive is used, active energy rays such as ultraviolet rays, visible light, electron beams, and X-rays can be irradiated to harden the adhesive composition layer to form the adhesive layer. As the active energy line, ultraviolet light is preferred. As the light source in this case, low pressure mercury lamp, medium pressure mercury lamp, high pressure mercury lamp, ultra high pressure mercury lamp, chemical lamp, black light lamp, microwave excited mercury lamp, metal halide can be used Object lights and so on.

(Adhesive layer)

The adhesive layer 31 of the optical laminate is a layer formed using an adhesive. In this specification, "adhesive" is a so-called pressure-sensitive adhesive by laying its main body on an attached object such as an image display element to exhibit adhesiveness. In addition, the active energy ray-curable adhesive described later can be irradiated with energy rays to adjust the degree of crosslinking and adhesion.

The adhesive is not particularly limited. Conventional adhesives with excellent optical transparency can be used. For example, acrylic, urethane, silicone, polyvinyl ether and other matrix polymers can be used. Adhesive. In addition, it may be an active energy ray-curable adhesive, a thermosetting adhesive, or the like. Among these, an acrylic resin excellent in transparency, adhesive strength, re-peelability (hereinafter also referred to as heavy industry), weather resistance, heat resistance, etc. is suitable as the adhesive for the matrix polymer. The adhesive layer is preferably composed of a reaction product of an adhesive composition containing a (meth)acrylic resin, a crosslinking agent, and a silane compound, and may also contain other components.

The adhesive layer 31 may also be formed using an active energy ray-curable adhesive. Active energy ray-curable adhesive, blending multifunctional acrylate and other ultraviolet rays into the adhesive composition The curable compound forms an adhesive layer and then irradiates it with ultraviolet rays to harden it, thereby forming a harder adhesive layer. Active energy ray-curing adhesive has the property of being irradiated with energy rays such as ultraviolet rays or electron beams to harden. The activated energy ray hardening adhesive has adhesiveness before the energy ray is irradiated. Therefore, it has the property of being able to adhere to the attached objects such as image display elements and harden by the irradiation of energy ray to adjust the adhesive force. Agent.

Active energy ray hardening adhesives generally contain acrylic adhesives and energy ray polymerizable compounds as main components. Usually, a crosslinking agent is further blended, and a photopolymerization initiator or photosensitizer can also be blended according to the needs.

The adhesive layer 31 preferably has an adhesion force (Fa) to the image display element 45 (attachment) that is relatively larger than the adhesion force (Fp) of the surface protection film to the polarizing laminate. In addition, it is preferable to use a storage elastic modulus or thickness of the adhesive layer 31 that is relatively larger than the storage elastic modulus or thickness of the adhesive layer as the bonding layer included in the polarizing laminate.

The adhesive force of the adhesive layer 31 with respect to the alkali-free glass substrate (thickness 0.7mm, "Eagle XG" manufactured by Corning) at a temperature of 23°C and a relative humidity of 55% is preferably 5N/25mm or more, or 8N/ 25mm or more, or 10N/25mm or more, preferably 50N/25mm or less, 40N/25mm or less, or 30N/25mm or less. The storage elastic modulus of the adhesive layer 31 at a temperature of 80° C. is preferably 0.01 MPa or more, or 0.02 MPa or more, and preferably 0.3 MPa or less, or 0.25 MPa or less, or 0.2 MPa or less. The measurement method of adhesion force and storage elastic modulus can use the measurement method of adhesion force and storage elastic modulus described in the above-mentioned lamination layer. The thickness of the adhesive layer 31 is preferably 10 μm or more, or 15 μm or more, or 20 μm or more, and preferably 40 μm or less, or 35 μm or less, or 30 μm or less. In addition, the adhesion force to the adherend other than the alkali-free glass substrate (thickness 0.7mm, Corning Corporation "Eagle XG") can be regarded as the same level as the adhesion force to the general alkali-free glass substrate.

(Peeling film)

The peeling film is a film that covers and protects the adhesive layer or supports the adhesive layer, and is peelable from the adhesive layer and has a function as a separator. Examples of the release film include films obtained by applying mold release treatments such as silicone treatment to the surface of the base film on the adhesive layer side. Examples of the resin material used as the base film include the same resin materials used as the above-mentioned protective layer. The resin film may have a one-layer structure or a multilayer resin film with a multilayer structure of two or more layers.

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

The release film can also display information related to the optical laminate by printing. As the information related to the optical laminate, a mark regarding the type of the polarizing laminate contained in the optical laminate, a mark showing the absorption axis direction of the polarizing plate contained in the polarizing laminate, and the like can be cited.

(Tape for peeling)

For the peeling tape, an adhesive tape having an adhesive layer formed on one side of a resin film can be used. As the resin film, a resin film for a surface protective film exemplified as a surface protective film can be used. The adhesive described in the adhesive layer 31 can be used to form the adhesive layer.

(Attachment)

The adherend to which the optical laminate is bonded by the adhesive layer 31 is not particularly limited, and examples thereof include image display elements of display devices. The image display element can be selected according to the type of display device. Examples of the image display element include display elements such as liquid crystal cells and organic EL display elements.

[Example]

Examples and comparative examples are shown below to more specifically illustrate the present invention, but the present invention is not limited to these examples.

[Strip evaluation]

The release film was peeled off from the optical laminate obtained in the Examples and Comparative Examples, and the optical laminate was bonded to a glass plate (holding stand) with the exposed adhesive layer to prepare a test sample. A peeling tape (Cellotape (registered trademark) (CT405-AP24), manufactured by NICHIBAN) was attached to the surface protective film on the surface of the optical laminate of the test sample to install it. The peeling tape has a size of 24 mm in width and 100 mm in length. In the top view of the optical laminate of the test sample, it is at the center of the short side where the notch is provided (if a quadrilateral without notch is assumed, it is at the center of the short side. Position), across the short side, from one end in the longitudinal direction of the peeling tape, the length range of 10 mm is arranged on the surface of the surface protection film as the installation end, and it is installed in this way (refer to FIG. 3). In the comparative example, the peeling tape was set in the same manner as above at the center of one short side.

The gripping side end of the peeling tape on the opposite side to the installation end of the optical laminate is carried by the chuck of the peeling device (Autograph AGS-50NX, manufactured by Shimadzu Corporation), so that it is opposite to the surface direction of the optical laminate. The angle (peeling angle) was 180°, the peeling speed was 300 mm/min, and the peeling tape was pulled up in the direction of the other short side opposite to the short side where the peeling tape was provided, and the peeling test was performed. As a result of the peeling test, the case where the surface protection film was peeled from the test sample was evaluated as A, and the case where the peeling tape was peeled from the surface protection film and the surface protection film was not peeled from the test specimen was evaluated as B. Perform this peel test on 10 or 20 test samples, and calculate the peel failure rate according to the following formula:

Peel failure rate [%]=(number of times of evaluation B/number of peel tests)×100.

[Example 1]

(Production of raw material laminate)

A linearly polarizing layer (thickness 8 μm) in which iodine was adsorbed and oriented on the polyvinyl alcohol-based resin film was prepared. A hard coat (HC) as a protective layer is formed on one side of the linear polarizing layer with a water-based adhesive interposed. The COP film side (the side opposite to the HC layer side) of the cyclic olefin-based resin (COP) film (thickness 25 μm) (hereinafter sometimes referred to as "25HC-COP film") of the layer. On the HC layer of the protective layer, the acrylic adhesive layer side of the surface protective film (thickness 53μm) was attached. In this surface protective film, the acrylic adhesive layer ( Thickness 15μm). A triacetyl cellulose (TAC) film (thickness 20 μm) formed as a protective layer was pasted on the other side of the linear polarizing layer through an aqueous adhesive. In this way, a polarizing plate (1) with a surface protective film was obtained. The polarizing plate (1) with surface protective film is a surface protective film (polyester resin film, acrylic adhesive layer), 25HC-COP film (HC layer, COP film), linear polarizing layer and TAC film in sequence Build up by layers.

Next, prepare the λ/4 plate (thickness 2μm) as the cured layer of the polymerizable liquid crystal compound, the adhesive cured layer (thickness 2μm) of the ultraviolet curable adhesive, and the cured layer of the polymerizable liquid crystal compound in sequence. A retardation layer formed by laminating positive C plates (thickness 3μm). The TAC film of the polarizing plate (1) with the surface protection film and the λ/4 plate of the retardation layer were bonded by the bonding layer (thickness 17 μm) as the adhesive layer. Next, an adhesive layer (1) with a release film in which an adhesive layer (thickness 25 μm) formed using an acrylic adhesive was formed on a release film (thickness 38 μm) was prepared. Paste the adhesive layer of the adhesive layer with release film (1) on the positive C plate side of the retardation layer pasted on the polarizing plate with surface protection film (1), and cut it into long sides A rectangle with a length of 37 mm and a length of 35 mm on the short side was obtained to obtain a raw material laminate (1). The raw material laminate (1) is a polarizing plate (1) with a surface protective film (surface protective film, 25HC-COP film, linear polarizing layer and TAC film), an adhesive layer belonging to an adhesive layer, and a retardation layer. (λ/4 plate, laminating layer, positive C plate) and adhesive layer with release film (1) (adhesive layer, release film) are laminated. In the raw material laminate (1), the thickness of the laminated part from the polarizing plate (25HC-COP film, linear polarizing layer, TAC film) to the retardation layer (λ/4 plate, bonding layer, positive C plate) is 77μm. In addition, the longitudinal direction of the raw material laminate (1) is parallel to the absorption axis of the linear polarizing layer.

(Production of optical laminate)

Using the apparatus shown in FIG. 8, prepare a laminate W in which the raw material laminate is laminated according to the procedure of the first step (above [a]) of the above description, and follow the procedure of the second step (above [b]) of the above description for The end faces corresponding to the 4 sides of the raw material laminate are polished. Furthermore, in accordance with the procedure of the second step (above [b]) described above, one corner portion at one end of one short side of the raw material laminated body was polished to obtain an optical laminated body having one notch. After polishing the end faces corresponding to the 4 sides, set the first position at a distance of 0.3 mm from the apex of the corner of the raw material laminate to the short side direction and the long side direction (distance Laa and distance Lab in Fig. 1). The resection starting point P1 and the second resection starting point P2 (refer to the first resection starting point P1b and the second resection starting point P2b in FIG. 1), and the first resection starting point P1 and the second resection The straight cut line formed by connecting the starting points P2 performs the grinding of the corners. In the above-mentioned polishing, the relative moving speed of 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 force between the surface protection film and the peeling tape was measured by the following procedure. The release film was peeled from the optical laminate obtained above to expose the adhesive layer, and the optical laminate with the release film removed from the exposed adhesive layer was bonded to a glass plate (holding stand) as a test sample. The peeling tape described in the above peeling evaluation item was attached to the surface of the surface protection film of the test sample, and the peeling device described in the peeling evaluation item was used to perform a 180° peeling test (peeling angle 180 °, a peeling speed of 300 mm/min), thereby measuring the adhesion force between the surface protection film and the peeling tape. The adhesion force is 9N/25mm. In addition, when the peeling tape was peeled off, the surface protective film did not peel off from the polarizing laminate.

In addition, using the peeling device described in the above peeling evaluation item, a 180° peeling test (peeling angle of 180°, peeling speed of 300mm/min) was performed to measure the acrylic adhesive layer side of the surface protective film and the 25HC-COP film The adhesion force between the sides of the HC layer turned out to be 0.03N/25mm.

[Example 2]

The two corners at both ends of one short side of the raw material layered body (1) were respectively polished to form two notches, except that the same procedure as in Example 1 was carried out to obtain an optical layered body. The two notches are the same as in Example 1. After grinding the end faces corresponding to the four sides, from the apex of the corner of the raw material laminate (1) to the first cutting start point P1 and the second cutting start point The distance to P2 is 0.3 mm, respectively, and the resection lines connecting the first resection starting point P1 and the second resection starting point P2 are all straight lines. The peeling evaluation of the optical laminate was performed. The results are shown in Table 1.

[Example 3]

The distance from the apex of the corner of the raw material layered body (the raw material layered body whose end faces corresponding to the four sides have been polished) to the first cutting start point P1 and the second cutting start point P2 is 0.2 mm, respectively. Otherwise, in the same manner as in Example 2, an optical laminate was obtained. The peeling evaluation of the optical laminate was performed.

The results are shown in Table 1.

[Example 4]

The distance from the apex of the corner of the raw material laminate (the raw material laminate after the end faces corresponding to the four sides has been ground) to the first resection starting point P1 and the second resection starting point P2 is 0.1 mm, Otherwise, in the same manner as in Example 2, an optical laminate was obtained. The peeling evaluation of the optical laminate was performed.

The results are shown in Table 1.

[Example 5]

(Production of raw material laminate)

A COP film with a thickness of 16μm as a protective layer formed with a hard coat (HC) layer (hereinafter sometimes referred to as "16HC-COP film"), and a TAC film that is not bonded as a protective layer, in addition to The same procedure as in Example 1 was carried out to obtain a polarizing plate (2) with a surface protective film. With surface protective film The polarizing plate (2) is formed by sequentially layering a surface protective film (polyester resin film, acrylic adhesive layer), 16HC-COP film (HC layer, COP film), and linear polarizing layer.

An adhesive layer (2) with a release film is prepared. An adhesive layer (thickness 10 μm) formed using an acrylic adhesive is formed on the release film (thickness 38 μm). Use the polarizing plate with surface protection film (2) instead of the polarizing plate with surface protection film (1), and use the bonding layer (thickness 5μm) as the adhesive layer to make the straight line of the polarizing plate with surface protection film (2) The polarizing layer side is attached to the λ/4 plate of the retardation layer. On the positive C plate side of the retardation layer, the adhesive layer of the adhesive layer (2) with the release film is attached instead of the adhesive with the release film Except for layer (1), the same procedure as in Example 1 was followed to obtain a raw material laminate (2).

The raw material laminate (2) is a polarizing plate (2) with a surface protective film (surface protective film, 16HC-COP film, linear polarizing layer), an adhesive layer belonging to an adhesive layer, and a retardation layer (λ/ 4-board, bonding layer, positive C-board), and adhesive layer (2) (adhesive layer, peeling film) with release film are laminated. In the raw material laminate (2), the thickness of the laminated part from the polarizing plate (16HC-COP film, linear polarizing layer) to the retardation layer (λ/4 plate, bonding layer, positive C plate) was 36 μm. In addition, the longitudinal direction of the raw material laminate (2) is parallel to the absorption axis of the linear polarizing layer.

(Production of optical laminate)

Using the raw material laminate (2), the relative moving speed of the laminate W and the rotary tool 60 was 700 mm/min, and the rotation speed of the rotary tool 60 was 4800 rpm, except that the same procedure as in Example 2 was used to obtain the optical Layered body. In the same procedure as in Example 1, the adhesion force between the surface protection film and the peeling tape and the adhesion force between the acrylic adhesive layer side of the surface protection film and the HC layer side of the 16HC-COP film were measured. As a result, They are 9N/25mm and 0.03N/25mm respectively.

[Example 6]

Only one corner portion at one end of one short side of the raw material laminated body (2) was polished to form a notch, except that the same procedure as in Example 5 was used to obtain an optical laminated body. The peeling evaluation of the optical laminate was performed. The results are shown in Table 1.

[Comparative Example 1]

The corners of the raw material laminate were not polished, and the notch was not formed. In the same manner as in Example 1, an optical laminate was obtained. The peeling evaluation of the optical laminate was performed. The results are shown in Table 1.

[Comparative Example 2]

The corners of the raw material laminate were not polished, and the notch was not formed. In the same manner as in Example 5, an optical laminate was obtained. The peeling evaluation of the optical laminate was performed. The results are shown in Table 1.

[Table 1]

In each example and each comparative example, in the peeling test, the layers (25HC-COP film or 16HC-COP film, linear polarizing layer, TAC film, adhesive layer, λ/4 plate) constituting the optical laminate were not confirmed , Laminating layer, positive C plate, adhesive layer) and the peeling between the glass plate (holding table).

1,1a: Optical laminate

10a, 10b, 10c, 10d: side

10eb: line

11b: Notch

15: Quadrilateral

15a: side 1

15b: Side 2

15c: side 3

15d: 4th side

Laa, Lab: distance

Pab: vertex

P1b: The first resection starting point

P2b: starting point of the second resection

α, β: shortest distance

Claims (10)

An optical laminate comprising a surface protective film, a polarizing laminate and an adhesive layer in this order. The polarizing laminate includes a polarizing plate with a protective layer on one or both sides of a linear polarizing layer, wherein, The surface protection film is provided so as to be peelable with respect to the polarizing laminate, The thickness of the aforementioned polarizing laminate is 120 μm or less, The planar shape of the aforementioned optical laminate is a shape having at least one notch, and the notch is obtained by cutting off one corner of a quadrilateral, The notch has a shape cut along a cutting line that passes through a first cutting start point P1 and a second cutting start point P2 respectively provided on the first side and the second side that constitute the vertex of the corner. , The first resection starting point P1 and the second resection starting point P2 are set to be 0.1 mm or more and 0.5 mm or less from the apex. The optical laminate according to claim 1, wherein the aforementioned quadrilateral is a square. The optical laminate according to claim 1 or 2, wherein the cutting line is a straight line or an arc-shaped curve. The optical laminate according to any one of claims 1 to 3, wherein the end surface in the notch portion of the optical laminate is a cutting surface formed by a rotating tool. The optical laminate according to any one of claims 1 to 4, wherein the lengths of the four sides of the aforementioned quadrilateral are in the range of 30 mm or more and 100 mm or less. The optical laminate according to any one of claims 1 to 5, which has at least two of the aforementioned notches, The notch is provided in such a way that two adjacent corners of the quadrilateral are cut off respectively. 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, wherein, on the side of the adhesive layer opposite to the side of the polarizing laminate, there is a release film that is peelable with respect to the adhesive layer . A peeling method, which peels off the aforementioned surface protective film from the optical laminate according to any one of claims 1 to 8, comprising: In the bonding step, the optical laminate is bonded to the adherend through the adhesive layer; A setting step of setting a peeling tape on the surface of the optical laminate on the side of the surface protection film; and In the peeling step, the surface protection film is peeled off from the optical laminate that has been attached to the adherend by pulling up the peeling tape; However, in the installation step, the peeling tape is installed so as to straddle one side where the notch is provided at the end of the optical laminate in the plan view shape. The peeling method according to claim 9, wherein the optical laminate is the optical laminate according to claim 6, The one side where the peeling tape is to be provided is the side provided with the notch at both ends.

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