KR20220160692A - Optical laminate and peeling method - Google Patents

Abstract

[PROBLEMS] To provide an optical laminate and a peeling method capable of favorably peeling a surface protection film.
[Solution] The optical layered body includes, in this order, a polarizing layered body including a surface protection film, a polarizing plate having a protective layer on one side or both sides of the linearly polarized light layer, and an adhesive layer. The surface protection film is disposed so that peeling is possible with respect to the polarizing laminate, and the thickness of the polarizing laminate is 120 μm or less. The planar view shape of the optical layered body is a shape having at least one cutout portion in which one corner portion of a quadrangle is cut. The cutout portion has a shape cut along a cutout line passing through the first cutout start point P1 and the second cutout start point P2 set on the first side and the second side constituting the vertex of the corner portion, respectively. The 1st notch start point P1 and the 2nd notch start point P2 are set so that the distance from a vertex may be 0.1 mm or more and 0.5 mm or less, respectively.

Description

Optical laminate and peeling method

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

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

In order to suppress contaminants and scratches on the surface of such a polarizing plate, a peelable surface protection film (also called a "protective film") is provided on one surface of the polarizing plate, and an adhesive layer and a peeling film are provided on the other surface. (It is also called a "separate film".) There are cases where it is distributed in the market (for example, Patent Literature 1, etc.). The surface protection film is peeled off and removed after bonding the polarizing plate to a member such as an image display element, for example, and the peeling film is peeled and removed when attaching the polarizing plate to a member such as an image display element of a display device, for example.

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

In a relatively small-sized polarizing plate used for smartphones, smart watches, etc., the surface protection film may be peeled by attaching a peeling tape to one side of the surface protection film and gripping the peeling tape to raise it up. When the tape for peeling was raised by such a peeling method, the tape for peeling peeled from the surface protection film, and the surface protection film could not be peeled from the polarizing plate in some cases.

An object of this invention is to provide the optical laminated body and peeling method which can peel a surface protection film satisfactorily.

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

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

The surface protection film is disposed so as to be peelable from the light-polarizing laminate,

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

The planar view shape of the optical laminate is a shape having at least one cutout portion in which one corner portion of a quadrangle is cut,

The cutout part has a shape cut along a cutout line passing through a first cutout start point P1 and a second cutout start point P2 set on the first side and the second side constituting the vertex of the corner portion, respectively. have,

The first cutting start point P1 and the second cutting start point P2 are set so that a distance from the vertex is 0.1 mm or more and 0.5 mm or less, respectively.

[2] The optical laminate according to [1], wherein the square 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 an end surface of the cutout portion of the optical laminate is a surface cut by a rotary tool.

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

[6] having at least two of the cutout portions,

The optical laminate according to any one of [1] to [5], wherein the cutout portion is formed so as to cut two adjacent corner portions of the quadrangle, respectively.

[7] The optical laminate according to any one of [1] to [6], wherein the polarizing laminate has a retardation layer on one or both surfaces of the polarizing plate.

[8] The optical laminate according to any one of [1] to [7], which further includes a release film that can be peeled from the pressure-sensitive adhesive layer on the side opposite to the light-polarizing laminate side of the pressure-sensitive adhesive layer.

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

A step of bonding the optical laminate to an adherend with the pressure-sensitive adhesive layer;

A step of attaching a peeling tape to the surface of the optical layered body on the side of the surface protection film;

The process of peeling the said surface protection film from the said optical laminated body bonded to the said adherend by grabbing and raising the said peeling tape

The peeling method includes, wherein the attaching step is to attach the peeling tape so as to span one side where the cutout portion is formed at an end portion of the planar view shape of the optical layered body.

[10] The optical layered body is the optical layered body described in [6],

The peeling method according to [9], wherein the one side to which the peeling tape is attached is a side in which the cutout portions are formed at both ends.

ADVANTAGE OF THE INVENTION According to this invention, the optical laminated body which can exfoliate a surface protection film satisfactorily can be provided.

1 is a schematic plan view schematically showing an example of an optical laminate of the present invention.
Fig. 2 is an x-x' sectional view of the optical laminate shown in Fig. 1;
Fig. 3 is a schematic plan view schematically showing an example of a step of peeling a surface protection film from the optical layered body of the present invention.
4 is a schematic plan view schematically showing another example of the optical layered body 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 a step of peeling a surface protection film from the optical layered body of the present invention.
Fig. 8 is a schematic perspective view schematically showing an example of a method for manufacturing an 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 of the drawings below are shown to aid understanding of the present invention, and the size or shape of each component shown in the drawings does not necessarily match the size or shape of the actual component.

(optical laminate)

1 is a schematic plan view schematically showing an example of an optical layered body of the present embodiment. Fig. 1 shows a schematic plan view of an optical laminate as seen from the surface protection film side. Fig. 2 is an x-x' sectional view of the optical laminate shown in Fig. 1;

As shown in FIG. 2, the optical laminate 1a of this embodiment is equipped with the surface protection film 41, the polarizing laminate 20, and the adhesive layer 31 in this order. The polarizing laminate 20 includes a polarizing plate 21 . This polarizing plate has a protective layer on one side or both sides of the linear polarization layer. The surface protection film 41 is formed so that exfoliation is possible with respect to the light-polarizing laminate 20 . The thickness of the polarizing laminate 20 is 120 μm or less.

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

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

It is preferable to set the shape of the notch line 10eb as follows. In the plan view shape of the optical layered body 1a, when the cutting line 10eb is found from the first cutting starting point P1b side toward the second cutting starting point P2b direction, the first cutting starting point P1b It is preferable to set the cutout line 10eb so that the shortest distance α from the first side 15a where ) is located increases continuously or gradually increases while including a section in which the shortest distance α becomes constant. . Further, in the plan view shape of the optical layered body 1a, when the cutting line 10eb is found from the first cutting starting point P1b side toward the second cutting starting point P2b direction, the second cutting starting point It is preferable to set the cutout line 10eb so that the shortest distance β from the second side 15b where P2b is located decreases continuously or gradually decreases while including a section in which the shortest distance β becomes constant. desirable.

The quadrangle 15 is a virtual plan view shape set to include the sides of the plan view shape of the optical layered body 1a. The quadrangle 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 quadrangle 15 shown in FIG. 1 is the side 10a and the side 10b in the plan view shape of the optical layered body 1a, respectively. ), and the entirety of the third side 15c and the fourth side 15d of the quadrangle 15 is the side 10c and the side 10d in the plan view shape of the optical laminate 1a, respectively. constitutes

In the planar view shape of the optical layered body 1a, the side 10a is on the opposite side of the first side 15a of the quadrangle 15 toward the vertex Pab from the first cutout starting point P1b. portion, and the side 10b is a portion on the opposite side of the second side 15b of the quadrangle 15 toward the vertex Pab from the second cutout starting point P2b.

In this way, the square 15 set with respect to the plan view shape of the optical layered body 1a extends the sides 10a and 10b in the plan view shape of the optical layered body 1a, and this It is a quadrangle including the intersection of the extended parts of the two sides as the vertex Pab. In addition, when the square 15 is set from the plan view shape of the optical stack 1a, the side extending from the plan view shape of the optical stack 1a is cut off at the corner of the square 15 so that the optical stack ( When it is assumed that 1a) is obtained, the area where the square 15 is cut is set to be minimized.

The distance Laa from the vertex Pab to the first notch starting point P1b and the distance Lab from the vertex Pab to the second notch starting point P2b are each independently 0.1 mm or more, and 0.2 mm or more. It may be mm or more, may be 0.3 mm or more, may be 0.5 mm or less, and may be 0.4 mm or less. The distance Laa and the distance Lab may be the same or different. As will be described later, when peeling the surface protection film 41 by attaching the peeling tape 35 (FIG. 3) to the side 10a, it is preferable that the distance Laa is larger than the distance Lab. When the distance Laa and the distance Lab are less than 0.1 mm, good peeling of the surface protection film 41 tends to be difficult to achieve. When the distance Laa and the distance Lab exceed 0.5 mm, the effective area when the optical laminate 1a is bonded to the image display element of the display device decreases, and the image display area in the display device narrows. there is a tendency

Assuming that the cutting line connecting the first cutting starting point P1b and the second cutting starting point P2b is a straight line, when the plan view area of the portion cut from the square 15 is S1, the optical laminate 1a ) is preferably 0.6 times or more of the area S1, may be 0.7 times or more, or 0.9 times or more of the area S1. It is good, and it is preferable that it is 1.6 times or less, 1.4 times or less may be sufficient, and 1.2 times or less may be sufficient.

3 is a schematic plan view schematically showing an example of a step of peeling a surface protection film from the optical layered body of the present embodiment. Since the optical layered body 1a has the notch 11b, peeling of the surface protection film 41 using the peeling tape 35 shown in FIG. 3 can be performed satisfactorily. Although the details of the peeling method of the surface protection film 41 using the peeling tape 35 are mentioned later, the surface protection film 41 can be peeled from the optical laminated body 1a as follows, for example. First, as shown in Fig. 3, the peeling tape 35 is applied to the surface of the optical layered body 1a on the surface protection film 41 side so as to span the side 10a where the notch 11b is formed. One end (hereinafter sometimes referred to as "attachment end") is attached. Then, the end of the peeling tape 35 on the opposite side to the sticking end is lifted up, and the peeling tape 35 is pulled in a direction from side 10a to side 10c (direction of arrow 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 cutout 11b is formed at the end of the side 10a to which the peeling tape 35 is attached. As a result, compared to the case where the notch 11b is not formed in the side 10a, it is considered that the surface protection film 41 is easily raised when the peeling tape 35 is raised up. Therefore, in the optical layered body 1a, peeling of the peeling tape 35 from the surface protection film 41 is suppressed, and the surface protection film 41 can be peeled satisfactorily by the peeling tape 35. can

4 is a schematic plan view schematically showing another example of the optical layered body of the present embodiment. In the optical layered body 1a shown in FIG. 1, the case of having one notch 11b has been described, but you may have two notches like the optical layered body 1b shown in FIG. 4, for example. , You may have three or four notches.

The optical layered body 1b shown in FIG. 4 further has a notched portion 11d in addition to the cutout portion 11b described in the optical layered body 1a shown in FIG. 1 . As shown in FIG. 4 , the planar view shape of the optical layered body 1b has a shape in which two corner portions of the quadrangle 15 are cut. The cutout 11b is as described above. The cutout portion 11d has a first cutout start point P1d (set at each of the first side 15a and the fourth side 15d, which are two sides constituting the vertex Pda of the corner portion of the rectangle 15) ( It has a cutout shape along the cutout line 10ed passing through the first cutout start point P1) and the second cutout start point P2d (the second cutout start point P2). The first cutting start point P1d and the second cutting start point P2d set on the first side 15a and the fourth side 15d, respectively, have a distance Lba and a distance Lbd from the vertex Pda. are located within a range of 0.1 mm or more and 0.5 mm or less, respectively. The distance Lba and the distance Lbd may be the same or different. When removing the surface protection film 41 by attaching the peeling tape 35 (FIG. 3) to the side 10a, it is preferable that the distance Lba is larger than the distance Lbd. Preferred ranges of the distance Lba and the distance Lbd are the same as those described for the distance Laa and the distance Lab.

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

It is preferable to set the shape of the notch line 10ed as follows. In the plan view shape of the optical layered body 1b, when the cutting line 10ed is found from the first cutting starting point P1d side toward the second cutting starting point P2d direction, the first cutting starting point P1d It is preferable to set the cutout line 10ed so that the shortest distance from the first side 15a where ) is located is continuously increased or gradually increases while including a section in which the shortest distance is constant. Further, in the plan view shape of the optical layered body 1b, when the cutting line 10ed is found from the first cutting starting point P1d side toward the second cutting starting point P2d direction, the second cutting starting point It is preferable to set the cutout line 10ed such that the shortest distance from the fourth side 15d where P2d is located is continuously reduced or gradually decreases while including a section in which the shortest distance is constant.

The square 15 set with respect to the planar view shape of the optical layered body 1b is set to include the side of the planar view shape of the optical layered body 1b, similarly to the optical layered body 1a described above. It is a flat shape. Part of the first side 15a, the second side 15b, and the fourth side 15d of the quadrangle 15 shown in FIG. 4 are sides in the plan view shape of the optical layered body 1b, respectively. (10a), the side 10b, and the side 10d, and the entirety of the third side 15c of the square 15 includes the side 10c in the plan view shape of the optical layered body 1b. are making up In the plan view shape of the optical layered body 1b, the side 10a is a line segment between the first cutting starting point P1b and the first cutting starting point P1d of the first side 15a of the square 15. , The side 10b is a part of the second side 15b of the quadrangle 15 opposite to the side from the second cutout starting point P2b toward the vertex Pab, and the side 10d is the quadrangle 15 It is a part on the opposite side of the side toward the vertex Pda from the second notch start point P2d among the fourth sides 15d of ).

The quadrangle 15 includes, as vertices Pab, sides 10a and an intersection formed by extending the sides 10b in the plan view shape of the optical layered body 1b, and the sides 10d and the sides ( An intersection formed by extending 10a) is included as a vertex Pda. In addition, when setting the square 15 from the plan view shape of the optical laminate 1b, the side extending from the plan view shape of the optical laminate 1b is the square 15 as in the case of the optical laminate 1a. If it is assumed that the optical laminate 1b is obtained by cutting the corner portion of ), the area where the square 15 is cut is set to be minimized. In addition, the rectangular shape set for the optical layered body 1b is set so that the optical layered body 1b can be obtained by cutting two corner portions of the rectangular shape.

Assuming that the cutting line connecting the first cutting starting point P1d and the second cutting starting point P2d is a straight line, when the plan view area of the portion cut from the quadrangle 15 is S2, the optical laminate 1b The planar view area Sb of the portion cut from the quadrangle 15 by the actual cutting line 10ed of ) is preferably 0.6 times or more, may be 0.7 times or more, or 0.9 times or more of the area S2. It may be, and it is preferable that it is 1.6 times or less, 1.4 times or less may be sufficient, and 1.2 times or less may be sufficient.

In the optical layered body 1b, a cutout 11b and a cutout 11d are formed at adjacent corner portions of the square 15. Therefore, the force required to grab and raise the surface protection film 41 using the peeling tape 35 in the above procedure is smaller than that in the case of peeling the surface protection film 41 in the optical layered body 1a. , it is considered that the surface protection film 41 became prone to occurrence of wrinkles. Thereby, in the optical laminated body 1b, the surface protection film 41 can be peeled more favorably with the tape 35 for peeling.

In the above, an optical layered body having one or two cutouts has been described as an example, but a rectangle can be set similarly to the above for the plan view shape of an optical layered body having three or four cutouts. In the case where the optical layered body has two or more cutouts, the shape of the square is assumed to be cut according to the number of cutouts the optical layered body has, assuming that the corners of the rectangle are cut according to the number of cutouts the optical layered body has. Set up to get a sieve.

When the optical laminate has two or more cutouts, the shapes of the cutouts may be the same or different. When the optical laminate has two or more notches, at least two notches are set for the plan view shape of the optical laminate, like the notches 11b and 11d of the optical laminate 1b shown in FIG. 4 . It is preferable to be formed so as to cut two adjacent corner parts of the rectangle to be.

If the optical laminates 1a and 1b (hereinafter, both are sometimes referred to as "optical laminate 1") have the above-described cutouts, they are cut in a shape different from the cutouts. It may have a notch shape. For example, in the optical laminate 1, in addition to the cutout described above, the corner portion of the square 15 is cut by a line passing through two points outside the range of the length described in the above distances (Laa, Lab, Lba, Lbd). It may have a broken notch shape.

It is preferable that the end face (end face in the stacking direction) of the notch 11 of the optical laminate 1 is a cut surface by a rotary tool. When the end face is a cut surface by a rotary tool, the end face of the surface protection film 41 or the polarizing laminate 20 included in the optical laminate 1 is slightly deformed along the rotation direction of the rotary tool. become a state In this deformed state, the end portion of the surface protection film 41 or the polarizing laminate 20 is not partially parallel to the plane direction of the optical laminate 1, and is slightly bent in the lamination direction or droops downward. say one thing The surface protection film 41 can be peeled much more favorably by the deformation mentioned above occurring in the end surface of the optical laminated body 1a.

It is preferable that the square 15 set with respect to the planar view shape of the optical layered body 1 is a square. In this specification, a quadrilateral refers to a quadrangle having four vertices at right angles (internal angles of 90°), and specifically refers to a square or rectangle. It is more preferable that the square 15 is rectangular.

The length of the four sides of the quadrangle 15 is preferably 30 mm or more independently, preferably 40 mm or more, 50 mm or more, 140 mm or more, or 150 mm or more. Moreover, it is preferable that it is 200 mm or less, may be 190 mm or less, may be 180 mm or less, may be 80 mm or less, may be 70 mm or less.

The surface protection film 41 is a film that can be peeled from the light-polarizing layered product 20, and is preferably formed so as to directly contact the light-polarizing layered product 20. The surface protection film 41 is also called a protection film, and is the surface of the polarizing laminate 20 in the manufacturing process of the optical laminate 1a, the manufacturing process of a display device to which the optical laminate 1a is applied, and the like. By covering and protecting the surface, stains and scratches on the surface can be suppressed. The surface protection film 41 can be peeled off and removed after bonding the optical layered body 1 to an adherend such as an image display element of a display device via, for example, the pressure-sensitive adhesive layer 31 .

The polarizing laminate 20 includes a polarizing plate 21 having a protective layer on one side or both sides of the linear polarizing layer. The thickness of the polarizing laminate 20 is 120 μm or less, may be 110 μm or less, may be 100 μm or less, may be 80 μm or less, or may be 40 μm or less. The thickness of the polarizing laminate 20 is usually 5 μm or more, may be 10 μm or more, may be 20 μm or more, may be 40 μm or more, or may be 50 μm or more. When end surface processing such as polishing is performed in the manufacturing process of the optical laminate 1, the adhesive constituting the adhesive layer 31 protrudes and covers the end surface of the optical laminate 1, and this adhesive is It may even reach the end surface of the surface protection film 41. In this case, since the surface protection film 41 is fixed to the pressure-sensitive adhesive layer 31 by the adhesive covering the end surface of the optical laminate 1, the surface protection film 41 is removed from the optical laminate 1. It is thought that this peeling becomes difficult. Since the distance between the surface protection film 41 and the adhesive layer 31 in the lamination direction of the optical laminate 1 decreases as the thickness of the polarizing laminate 20 decreases, the optical laminate using the adhesive It is thought that the coating of the end face of (1) makes it easy to be in a state in which the surface protection film 41 is difficult to peel. The optical layered body 1 has cutout portions 11b and 11d as described above. Therefore, even when the thickness of the polarizing layered product 20 is small, the surface protection film 41 can be peeled favorably.

The polarizing laminate 20 may be the polarizing plate 21 itself, as shown in FIG. 2 , or may have optical functional layers other than the polarizing plate 21 . As optical function layers other than the polarizing plate 21, for example, a retardation layer; reflective film; Transflective reflective film; brightness enhancing film; optical compensation film; A film with an anti-glare function, etc. are mentioned.

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

The optical laminate shown in FIG. 5 shows an example in the case where the polarizing laminate 20 is a laminate of the polarizing plate 21 and the retardation layer 22 . The polarizing plate 21 and the retardation layer 22 may be laminated through a bonding layer such as an adhesive layer or a cured adhesive layer. When the polarizing laminate 20 includes the retardation layer 22 , the retardation layer 22 may be formed on one side or both sides of the polarizing plate 21 . When the polarizing laminate 20 includes two or more layers of retardation layers 22, one or more retardation layers 22 may be provided on both sides of the polarizing plate 21, or only on one side of the polarizing plate 21. A retardation layer 22 of more than one layer may be provided. The retardation layer is not particularly limited, and examples thereof include a 1/2 wavelength retardation layer, a 1/4 wavelength retardation layer, a 1/4 wavelength retardation layer having reverse wavelength dispersion, and a positive C plate.

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

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

The pressure-sensitive adhesive layer 31 can be used to bond the optical layered body 1 to an adherend such as an image display element of a display device. The pressure-sensitive adhesive layer 31 is preferably formed so as to directly contact the polarizing laminate 20 . In the polarizing laminate 20, when the adhesive layer is used for bonding the polarizing plate and the optical function layer and/or bonding the phase contrast layers to each other, the adhesive layer 31 is formed in the stacking direction of the optical laminate 1. It becomes the adhesive layer in the most distant position from the surface protection film 41 in .

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

The optical laminate 1 can be used for display devices such as smart phones and smart watches. As a display device, a liquid crystal display device, an organic EL (electroluminescence) display device, etc. are mentioned. After the optical layered body 1 is bonded to an adherend such as an image display element of a display device by the pressure-sensitive adhesive layer 31, the surface protection film 41 is peeled off. Accordingly, the polarizing laminate 20 included in the optical laminate 1 can be incorporated into a display device.

(Method of manufacturing optical laminate)

The optical layered body 1 is formed, for example, by forming a notch with respect to a raw material layered product obtained by cutting a layered product having a surface protection film, a polarizing layered product, an adhesive layer, and a release film in this order into a predetermined shape and size. can be manufactured As a method of forming a notch in the raw material laminate, for example, a method of polishing the end surface (end surface parallel to the stacking direction) of the raw material laminate, and using one of Thomson blades, laser cutters, etc. for the raw material laminate, or The method of cutting by using in combination of 2 or more types is mentioned. Among these, it is preferable to form notches by polishing in order to suppress fuzz and the like generated on the end face of the optical laminate 1 in the lamination direction and to obtain good dimensional accuracy of the optical laminate 1. do. The polishing and cutting described above may be performed with respect to one sheet of raw material laminate, or may be performed simultaneously by laminating two or more raw material laminates.

The planar view shape of the raw material layered body may be selected according to the shape of the optical layered body 1, and is not particularly limited. The planar view shape of the raw material layered body is preferably a rectangle 15 (FIGS. 1 and 4) set with respect to the planar view shape of the optical layered body 1 described above in the case of forming cutouts by polishing. And, it is more preferable that it is square, and it is more preferable that it is rectangular. When the planar view shape of the raw material laminate is the quadrangle 15 described above, the cutting area of the raw material laminate can be reduced.

In the case of manufacturing the optical laminate 1 from the raw material laminate having the plan view shape of the quadrangle 15 described in FIGS. 1 and 4, the corners of the quadrangle 15 are the vertex Pab and/or the vertex Pda. ) It is only necessary to form the cutout portions 11b and 11d by performing polishing or the like so as to be cut into a shape of a right triangle (for example, a right-angled isosceles triangle).

8 is a schematic perspective view schematically showing an example of a method for manufacturing an optical laminate of the present embodiment. A manufacturing method for manufacturing the optical laminate 1 by polishing from a raw material laminate is, for example, the following steps:

[a] First step of obtaining a laminate (W) by stacking a plurality of raw material laminates, and

[b] A rotary tool 60 having a cutting edge rotating about a rotation axis R along a direction parallel to the end face of the laminate W and orthogonal to the laminate direction is applied to the laminate W. 2nd process of cutting the end face of the laminated body W by relatively moving it with respect to

can include

In the manufacturing method of the optical layered body 1, for example, after performing the first step (above [a]), first, the second step (above [b]) for the four sides of the raw material layered body having a rectangular shape in plan view. After that, polishing by the second step (above [b]) is performed on the rectangular corner portion to form a notch.

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

In the second step, the end face of the laminate W obtained in the first step is cut with the rotary tool 60 to form a cut face on the end face in the cutout portion of the optical laminate 1. This is a step of forming the optical layered body 1 by doing so.

The cutting process performed in the 2nd process can be performed by the apparatus provided with the support part 50 and two rotary tools 60, for example, as shown in FIG. The support portion 50 presses the laminate W from the top and bottom so that the laminate W itself does not move during cutting and is for fixing the stacked raw material laminates so that they do not warp. The rotary tool 60 is for cutting the end surface of the multilayer body W, and can be rotated around the rotational axis R.

The support portion 50 includes a plate-like substrate (moving means for the laminate W) 51; a frame 52 in the form of a door disposed on the substrate 51; a rotary table 53 disposed on the substrate 51 and capable of rotating around a central axis; It may be provided with a cylinder 54 installed at a position facing the rotary table 53 in the frame 52 and capable of moving up and down. The multilayer body W is sandwiched and fixed by the rotary table 53 and the cylinder 54 via the jig 55.

The rotary tool 60 has a disc-shaped rotary body that rotates around the rotary shaft R. The direction of rotation of the rotating body is indicated by an arrow in FIG. 8 . A plurality of (e.g., 2 to 10, preferably 2 to 10) are provided at intervals in the rotational direction of the rotating body on the other side of the rotating body (a surface facing the end face of the stacked product W and parallel to the end face). At least 3 to 7) cutting edges are arranged. It is preferable that the rotating shaft R is set so as to pass through the center of the other side of the rotating body. The cutting edge is installed so as to protrude from the other side of the rotating body toward the end surface of the multilayer body W, and the rotating body rotates around the rotating shaft R in a state in which the cutting edge abuts against the end surface of the multilayer body W. By doing so, the end face of the multilayer body W can be cut.

On both sides of the substrate 51, two rotary tools 60 are installed facing each other. The rotary tool 60 is movable in the direction of the rotational axis R according to the size of the laminated body W, and the substrate 51 is movable to pass between the two rotary tools 60 . In cutting, after fixing the multilayer body W to the support portion 50 and appropriately adjusting the position of the rotary tool 60 in the direction of the rotary axis R, the rotary tool 60 is moved to the rotary axis R While rotating around ), the substrate 51 is moved so that the laminated body W passes between the rotating tools 60 facing each other. Accordingly, while relatively moving the rotary tool 60 with respect to the laminate W along a direction parallel to the end face of the laminate W and orthogonal to the laminate direction, the cutting edge of the rotary tool 60 It is possible to perform a cutting process in which the end faces of the multilayer body W are brought into contact with the facing exposed end faces of the multilayer body W, and the end faces thereof are shaved off.

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

(How to peel the surface protection film)

7 is a schematic cross-sectional view schematically showing an example of a step of peeling a surface protection film from the optical layered body of the present embodiment. The peeling method of peeling the surface protection film 41 from the optical laminated body 1 includes the steps of bonding the optical laminated body 1 to the image display element 45 (adhered body) with the pressure-sensitive adhesive layer 31 ( 7), the step of attaching the tape 35 for peeling to the surface of the surface protection film 41 side of the optical layered body 1 (Fig. 3, Fig. 7(a)), and the tape 35 for peeling The process of peeling the surface protection film 41 from the optical laminated body 1 bonded to the image display element 45 by pulling up (FIG. 7(b) and (c)) is included.

In the step of attaching the peeling tape 35, in the plan view shape of the optical laminate 1, the peeling tape 35 is formed so as to span one side in which the cutout 11b or the cutout 11d is formed at the end. attach In FIG. 3, an example of attaching the peeling tape 35 so as to span the side 10a is shown, but the side having the cutout 11b or 11d at the end (for example, the side shown in FIGS. 1 and 4 ( 10b) and the side 10d shown in FIG. 4) may be used. As shown in FIG. 4 , when the notch 11b and the notch 11d are formed at both ends of the side 10a, the surface protection film 41 can be further removed by pulling up the peeling tape 35. In order to peel better, it is preferable that the tape 35 for peeling is affixed so that it spans the edge 10a. The peeling tape 35 is usually directly attached to the surface of the surface protection film 41 .

The process of bonding to the image display element 45 is performed after peeling the peeling film 32 from the optical laminated body 1, when the optical laminated body 1 has the peeling film 32 (FIG. 6). The process of bonding to the image display element 45 may be performed before or after the process of attaching the tape 35 for peeling.

In the step of peeling the surface protection film 41, the end on the opposite side to the attachment end, which is the end attached to the surface on the surface protection film 41 side, among the peeling tapes 35 (hereinafter, "gripping side end") ) is held, and the peeling tape 35 is applied to the side opposite to the image display element 45 side (in the upper right direction in Fig. 7(a), in the direction of the arrow in Fig. 7(a)). catch and raise By bending the end of the peeling tape 35 on the holding side back to the attaching end side (in the direction of the arrow in Fig. 7(b)) and then pulling it toward the bending direction (in the direction of the arrow in Fig. 7(c)) , The surface of the polarizing laminate 20 can be exposed by peeling the surface protection film 41 from the optical laminate 1 .

Although peeling of the surface protection film 41 may be performed by hand, it can be automated using a peeling device. In the case of using a peeling device, surface protection is achieved by gripping the gripping side end of the peeling tape 35 with a chuck of the peeling device, moving the chuck and the optical laminate 1 relative to each other, and holding the peeling tape 35 up. The film 41 can be peeled off.

As described above, by attaching the peeling tape 35 to the side where the cutout 11b and/or the cutout 11d are formed at the end in the plan view shape of the optical laminate 1, the peeling tape ( 35), it is possible to reduce the force necessary for gripping and raising the surface protection film 41. Therefore, according to the peeling method of this embodiment, compared with the case where a surface protection film is peeled from the optical laminated body which does not have a notch, a surface protection film can be peeled favorably. In particular, as in the optical layered body 1b shown in FIG. 4, when the cutout 11b and the cutout 11d are formed at both ends of the side 10b, the tape 35 for peeling is formed on the side 10b. The surface protection film 41 can be peeled off more satisfactorily by attaching.

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

(surface protection film)

A surface protection film is formed on the surface of a light-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 one in which an adhesive layer was formed on the resin film for surface protection films, or may be formed of 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, and more preferably 30 to 120 μm.

Examples of the resin constituting the resin film for surface protection films include polyolefin-based resins such as polyethylene-based resins and polypropylene-based resins; Cyclic polyolefin resin; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polycarbonate-based resin; (meth)acrylic-type resin etc. are mentioned. Among these, polyester-type resins, such as polyethylene terephthalate, are preferable. The resin film for surface protection films may have a single layer structure, but may have a multilayer structure of two or more layers. The resin film for surface protection films may be a film subjected to stretching treatment such as uniaxial stretching or biaxial stretching.

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

The adhesion (Fp) can be measured in the following procedure. What cut the optical laminated body 1 into a rectangle of 150 mm x 25 mm is bonded to an alkali-free glass substrate (thickness 0.7 mm, "Eagle XG" by Corning) with the adhesive layer 31, and it is set as a test piece. This test piece was put into an autoclave at an internal temperature of 50 ° C and an internal pressure of 490.3 kPa (gauge pressure) for 20 minutes, exposed to a heated and pressurized environment, and then stored for 24 hours in an atmosphere with a temperature of 23 ° C and a relative humidity of 55% RH for evaluation. do as a sample. Regarding this evaluation sample, in accordance with JIS K6854-2: 1999 “Adhesives-Peel Adhesion Strength Test Method-Part 2: 180° Peeling”, a peeling device (“Autograph AGS-50NX” manufactured by Shimadzu Corporation) Using, a 180° peel test is performed at a moving speed of 300 mm/min, and the measured peel force is referred to as the adhesion force (Fp).

When the surface protection film is one in which an adhesive layer is formed on a resin film for surface protection film, the thickness of the pressure-sensitive adhesive layer is preferably 5 μm or more, may be 10 μm or more, may be 15 μm or more, and may be 30 μm or less. Preferably, it may be 25 μm or less, and may be 20 μm or less.

The surface protection film described above can be obtained by forming an adhesive layer on the surface of the resin film for surface protection films by applying and drying the adhesive. As needed, surface treatment (e.g., corona treatment, etc.) may be performed on the coated surface of the adhesive of the resin film for surface protection films in order to improve adhesion, even if a thin layer such as a primer layer (also referred to as an undercoating layer) is formed. good night. Moreover, as needed, when a surface protection film has an adhesive layer, you may have a peeling layer for coat|covering and protecting the surface on the opposite side to the resin film side for surface protection films of the said adhesive layer. This peeling layer can be peeled at an appropriate timing when bonding to the polarizing laminate.

A self-adhesive film that can be used as a surface protection film is a film that is attached by itself without providing a means for attaching an adhesive layer or the like and can maintain the attached state. The self-adhesive film can be formed using, for example, a polypropylene-based resin or a polyethylene-based resin.

(Polarizing laminate)

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 contain only a polarizing plate, or may contain a polarizing plate and optical functional layers other than the polarizing plate. As this optical function layer, the above is mentioned. One layer may be sufficient as an optical function layer, and two or more layers may be sufficient as it. Between the linear polarization layer and the protective layer, between the polarizing plate and the optical function layer, and between the optical function layers in the case where the optical function layer is ideally layered in two layers are bonded through a bonding layer such as a pressure-sensitive adhesive layer or a cured adhesive layer, may be

(linear polarization layer)

The linearly polarized layer has a property of transmitting linearly polarized light having a plane of vibration orthogonal to the absorption axis when unpolarized light is incident therethrough. The linear polarization layer may include a polyvinyl alcohol (hereinafter sometimes abbreviated as "PVA")-based resin film, orienting a dichroic dye in a polymerizable liquid crystal compound to polymerize the polymerizable liquid crystal compound. A cured film may be used.

As the linearly polarizing layer comprising a PVA-based resin film, for example, a hydrophilic polymer film such as a PVA-based film, a partially formalized PVA-based film, an ethylene/vinyl acetate copolymer-based partially saponified film, and a dichroic substance such as iodine or a dichroic dye and those to which dyeing treatment and stretching treatment were performed by . Since the optical properties are excellent, it is preferable to use a linear polarization layer obtained by dyeing a PVA-based resin film with iodine and uniaxially stretching it.

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

The degree of saponification of the PVA-based resin is usually about 85 to 100 mol%, preferably 98 mol% or more. The PVA-based resin may be modified, and for example, polyvinyl formal or polyvinyl acetal modified with aldehydes can be used. The average degree of polymerization of the PVA-based resin is usually about 1,000 to 10,000, preferably about 1,500 to 5,000. The average degree of polymerization of PVA-based resin can be obtained in accordance with JIS K 6726 (1994). When the average degree of polymerization is less than 1000, it is difficult to obtain desirable polarization performance, and when it exceeds 10000, film workability may be poor.

As a method for producing a linear polarization layer containing another PVA-based resin film, first, a base film is prepared, a solution of a resin such as a PVA-based resin is applied on the base film, and drying to remove the solvent is performed to remove the base film. What includes the process of forming a resin layer on it is mentioned.

In addition, a primer layer can be formed in advance on the surface on which the resin layer of the base film is formed. As the base film, a resin film such as PET or a film using a thermoplastic resin that can be used for a protective layer described later can be used. Examples of the material for the primer layer include a resin obtained by crosslinking a hydrophilic resin used in the linear polarization layer.

Subsequently, the amount of solvent such as water in the resin layer is adjusted as necessary, and then the base film and the resin layer are uniaxially stretched, and then the resin layer is dyed with a dichroic dye such as iodine to form the dichroic dye into the resin layer. is adsorbed to orient. Then, if necessary, a washing step is performed in which the resin layer in which the dichroic dye is adsorbed and oriented is treated with an aqueous solution of boric acid, and the aqueous solution of boric acid is washed off. In this way, a resin layer in which the dichroic dye is adsorbed and oriented, that is, a film of a linearly polarized light layer is produced. A well-known method can be employ|adopted for each process.

Uniaxial stretching of the base film and the resin layer may be performed before dyeing, may be performed during dyeing, may be performed during boric acid treatment after dyeing, or may be uniaxially stretched in a plurality of these steps. The base film and the resin layer may be uniaxially stretched in the MD direction (film transport direction). In this case, they may be uniaxially stretched between rolls having different circumferential speeds, or uniaxially stretched using a hot roll. In addition, the base film and the resin layer may be uniaxially stretched in the TD direction (direction perpendicular to the film transport direction), and in this case, a so-called tenter method can be used. Further, the stretching of the base film and the resin layer may be dry stretching performed in air or wet stretching performed in a state where the resin layer is swollen with a solvent. In order to express the performance of the linear polarization layer, the draw ratio is 4 times or more, preferably 5 times or more, and particularly preferably 5.5 times or more. Although there is no upper limit in particular of the draw ratio, it is preferably 8 times or less from the viewpoint of suppressing breakage or the like.

The linearly polarized light layer produced by the above method can be obtained by laminating the protective layer described later and then peeling off the base film. According to this method, further thinning of the linear polarization layer is possible.

The thickness of the linear polarization layer comprising 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. good night.

As a method for producing a linear polarizing layer, which is a cured film obtained by orienting a dichroic dye in a polymerizable liquid crystal compound and polymerizing the polymerizable liquid crystal compound, a composition for forming a polarizing layer containing a polymerizable liquid crystal compound and a dichroic dye on a base film. and a method of forming a linear polarization layer by applying a polymerizable liquid crystal compound and polymerizing and curing the polymerizable liquid crystal compound while maintaining the liquid crystal state. The linear polarization layer obtained in this way is in a laminated state on a base film, and the linear polarization layer with a base film may be 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 a protective layer described later can be used.

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

The composition for forming a polarizing layer may include a solvent, a polymerization initiator such as a photopolymerization initiator, a photosensitizer, and a polymerization inhibitor. Polymerizable liquid crystal compounds, dichroic dyes, solvents, polymerization initiators, photosensitizers, polymerization inhibitors, etc. included in the composition for forming a polarizing layer may be known. For example, Japanese Patent Laid-Open No. 2017-102479, What is illustrated in Unexamined-Japanese-Patent No. 2017-83843 can be used. In addition, as the polymerizable liquid crystal compound, the compounds exemplified as the polymerizable liquid crystal compound used in order to obtain a cured product layer as a retardation layer described later may be used. As for the method of forming the linear polarization layer using the composition for forming the polarization layer, the method exemplified in the above publication can also be employed.

(Polarizer)

The linear polarization layer can be made into a polarizing plate by laminating a protective layer on one side or both sides thereof. This polarizing plate is a so-called linear polarizing plate. As the protective layer that can be laminated on one side or both sides of the linear polarization layer, for example, a film formed of a thermoplastic resin having excellent transparency, mechanical strength, thermal stability, water barrier properties, isotropy, and stretchability is used. Specific examples of such a thermoplastic resin include cellulosic resins such as triacetyl cellulose; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polyethersulfone resin; polysulfone resin; polycarbonate resin; polyamide resins such as nylon and aromatic polyamide; polyimide resin; Polyolefin resins, such as polyethylene, a polypropylene, and an ethylene-propylene copolymer; cyclic polyolefin resins (also referred to as norbornene-based resins) having a cyclo-based and norbornene structure; (meth)acrylic resin; polyarylate resin; polystyrene resin; polyvinyl alcohol resins, and mixtures thereof. When protective layers are laminated on both sides of the linear polarization layer, the resin compositions of the two protective layers may be the same or different. In addition, in this specification, "(meth)acryl" means that either acryl or methacryl may be sufficient. "(meth)", such as (meth)acrylate, has the same meaning.

The protective layer may have retardation characteristics, or may have a functional layer such as a hard coat layer or an antireflection layer. It is preferable that it is 3 micrometers or more, and, as for the thickness of a protective layer, it is more preferable that it is 5 micrometers or more. Further, the thickness of the protective layer is preferably 50 μm or less, and more preferably 30 μm or less. In addition, the above-mentioned upper limit and lower limit can be combined arbitrarily.

(phase difference layer)

The polarizing laminate may contain a retardation layer. The retardation layer may contain a layer of a cured material of a polymerizable liquid crystal compound or may be a stretched resin film.

When the retardation layer includes a cured material layer of a polymerizable liquid crystal compound, as the polymerizable liquid crystal compound, a rod-shaped polymerizable liquid crystal compound and a disk-shaped polymerizable liquid crystal compound may be used, either of which may be used, A mixture containing both of these may be used. When the rod-like polymerizable liquid crystal compound is horizontally aligned or vertically aligned with respect to the substrate layer, the optical axis of the polymerizable liquid crystal compound coincides with the major axis direction of the polymerizable liquid crystal compound. When the discoid polymerizable liquid crystal compound is aligned, 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, those described in, for example, Japanese Patent Publication No. 11-513019 (Claim 1 and the like) can be suitably used. As the discoid polymerizable liquid crystal compound, those described in Japanese Patent Laid-Open No. 2007-108732 (paragraphs [0020] to [0067], etc.) and Japanese Patent Laid-Open No. 2010-244038 (paragraphs [0013] to [0108], etc.) are preferred. available.

What is necessary is just to orientate a polymerizable liquid crystal compound in an appropriate direction in order for the hardened|cured material layer formed by polymerizing a polymerizable liquid crystal compound to express an in-plane retardation. When the polymerizable liquid crystal compound is rod-shaped, in-plane retardation is developed by orienting the optical axis of the polymerizable liquid crystal compound horizontally with respect to the plane of the substrate layer, and in this case, the optical axis direction and the slow axis direction coincide. When the polymerizable liquid crystal compound is discoid, in-plane retardation is developed by orienting the optical axis of the polymerizable liquid crystal compound horizontally with respect to the plane of the substrate layer, and in this case, the optical axis and the slow axis are orthogonal. The alignment state of the polymerizable liquid crystal compound can be adjusted by a combination of the alignment layer and the polymerizable liquid crystal compound.

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

When the retardation layer includes a cured layer of a polymerizable liquid crystal compound, the retardation layer may include an alignment layer. The alignment layer has an alignment regulating force for orienting the polymerizable liquid crystal compound in a desired direction. The alignment layer may be a vertical alignment layer in which the molecular axis of the polymerizable liquid crystal compound is vertically aligned with respect to the substrate layer, or a horizontal alignment layer in which the molecular axis of the polymerizable liquid crystal compound is horizontally aligned with respect to the substrate layer may be used, or the molecules of the polymerizable liquid crystal compound An inclination orientation layer in which an axis is obliquely oriented with respect to the substrate layer may be used. The first orientation layer and the second orientation layer may be the same orientation layer or different orientation layers.

As the alignment layer, it is preferable to have resistance to solvents that do not dissolve when the composition for forming a liquid crystal layer is applied or the like, and has heat resistance to removal of solvents or heat treatment for alignment of polymerizable liquid crystal compounds. Examples of the orientation layer include an orientation polymer layer formed of an orientation polymer, an optical orientation polymer layer formed of an optical orientation polymer, and a groove orientation layer having a concave-convex pattern and a plurality of grooves on the surface of the layer.

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

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

Examples of the resin film used for the stretched resin film include a film containing a thermoplastic resin that can be used to form a protective layer. Examples of the stretching treatment include uniaxial stretching and biaxial stretching. The stretching direction in the stretching treatment may be the longitudinal direction of the unstretched resin, a direction orthogonal to the longitudinal direction, or a direction intersecting with the longitudinal direction. In the case of uniaxial stretching, unstretched resin may be stretched in any one of these directions. Biaxial stretching may be simultaneous biaxial stretching in which the film is simultaneously stretched in two of these directions, or sequential biaxial stretching in which the film is stretched in a desired direction and then in another direction.

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

(bonding layer)

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

The adhesion (Fb) between the bonding layer bonding each layer constituting the polarizing laminate and each layer bonded thereto is the bonding strength (Fp) of the surface protection film 41 to the polarizing laminate 20, respectively. ) is greater than 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 (Fa) of the pressure-sensitive adhesive layer 31 described later to the image display element 45 (adhered body) is similar to the normal adhesion (Fb), and the polarizing laminate 20 of the surface protection film 41 It is greater than the adhesion (Fp) to The difference between the adhesion Fa and the adhesion Fp is, for example, 1 N/25 mm or more, preferably 3 N/25 mm or more, and usually 50 N/25 mm or less.

When the adhesive force Fb is smaller than the adhesive force Fp, after bonding the optical laminated body 1 to the image display element 45 with the adhesive layer 31, when peeling the surface protection film 41, There is a possibility that the respective layers constituting the optical laminate 20 peel off from each other. In addition, when adhesive force Fa is smaller than adhesive force Fp, after bonding optical laminated body 1 to image display element 45 with adhesive layer 31, when peeling surface protection film 41 , Separation may occur between the pressure-sensitive adhesive layer 31 and the layer of the image display element 45.

The adhesion Fa may be larger than, smaller than, or the same as the adhesion Fb. When the adhesion Fa is smaller than the adhesion Fb, the polarizing laminate 20 bonded to the image display element 45 is peeled off from the image display element 45 to bond a new optical laminate 1. work etc. can be performed easily.

The storage elastic modulus of the pressure-sensitive adhesive layer as a bonding layer at a temperature of 80 ° C. is preferably 0.01 MPa or more, may be 0.02 MPa or more, and is preferably 0.3 MPa or less, may be 0.25 MPa or less, or may be 0.2 MPa or less. The storage elastic modulus is obtained by punching a pressure-sensitive adhesive layer laminate having a thickness of 0.2 mm produced by laminating a plurality of pressure-sensitive adhesive layers into a cylinder having a diameter of 8 mm as a measurement sample, and in accordance with JIS K7244-6, commercially available viscoelasticity measurement It can be measured under the following conditions using an apparatus.

Normal force FN: 1 N

Distortion γ: 1%

Frequency: 1Hz

Temperature: 80℃

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

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

Examples of water-based adhesives include adhesives 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, but a method of drying using, for example, a hot air dryer or an infrared dryer can be employed.

Examples of active energy ray-curable adhesives include solvent-free active energy ray-curable adhesives containing a curable compound that is cured by irradiation with active energy rays such as ultraviolet rays, visible light, electron beams, and X-rays. Adhesion between layers can be improved by using a non-solvent type active energy ray-curable adhesive.

Since the active energy ray-curable adhesive exhibits good adhesiveness, it is preferable to include either one or both of a cationically polymerizable curable compound and a radically polymerizable curable compound. The active energy ray-curable adhesive may further include a cationic polymerization initiator or a radical polymerization initiator for initiating a curing reaction of the curable compound.

As the cationically polymerizable curable compound, for example, an epoxy-based compound (a compound having one or two or more epoxy groups in a molecule), an oxetane-based compound (a compound having one or two or more oxetane rings in a molecule), or a combination thereof. can be heard

Examples of the radical polymerizable curable compound include (meth)acrylic compounds (compounds having one or two or more (meth)acryloyloxy groups in the molecule), other vinyl compounds having radically polymerizable double bonds, or combinations thereof. can be heard

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

The active energy ray-curable adhesive may contain additives such as ion trapping agents, antioxidants, chain transfer agents, tackifiers, thermoplastic resins, fillers, flow regulators, plasticizers, antifoaming agents, antistatic agents, leveling agents, solvents, etc., if necessary. have.

In the case of using an active energy ray-curable adhesive, an adhesive layer may be formed by curing the adhesive composition layer by irradiating active energy rays such as ultraviolet rays, visible light, electron beams, and X-rays. As the active energy ray, ultraviolet rays are preferable, and as the light source in this case, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultra high pressure mercury lamp, a chemical lamp, a black light lamp, a microwave excited mercury lamp, a metal halide lamp, etc. can be used.

(Adhesive layer)

The pressure-sensitive adhesive layer 31 of the optical laminate is a layer formed using a pressure-sensitive adhesive. In this specification, "adhesive" expresses adhesiveness by sticking itself to an adherend such as an image display element, and is called a so-called pressure-sensitive adhesive. In addition, the degree of crosslinking and adhesive strength of the active energy ray-curable pressure-sensitive adhesive described later can be adjusted by irradiating energy rays.

As the pressure-sensitive adhesive, conventionally known pressure-sensitive adhesives having excellent optical transparency may be used without particular limitation, and for example, pressure-sensitive adhesives having a base polymer such as acrylic, urethane, silicone, or polyvinyl ether may be used. In addition, an active energy ray-curable pressure-sensitive adhesive, a heat-curable pressure-sensitive adhesive, or the like may be used. Among these, an adhesive having an acrylic resin as a base polymer having excellent transparency, adhesiveness, re-peelability (hereinafter also referred to as reworkability), weather resistance, heat resistance, and the like is suitable. The pressure-sensitive adhesive layer is preferably composed of a reaction product of a pressure-sensitive adhesive composition containing a (meth)acrylic resin, a crosslinking agent, and a silane compound, and may contain other components.

The pressure-sensitive adhesive layer 31 may be formed using an active energy ray-curable pressure-sensitive adhesive. The active energy ray-curable pressure-sensitive adhesive can form a harder pressure-sensitive adhesive layer by mixing an ultraviolet curable compound such as a multifunctional acrylate with the pressure-sensitive adhesive composition, forming the pressure-sensitive adhesive layer, and then irradiating and curing the pressure-sensitive adhesive layer with ultraviolet rays. The active energy ray-curable pressure-sensitive adhesive has a property of being cured by being irradiated with energy rays such as ultraviolet rays and electron beams. An activated energy ray-curable pressure-sensitive adhesive has adhesiveness even before energy ray irradiation, and therefore adheres to an adherend such as an image display element and is cured by energy ray irradiation to adjust adhesion.

An active energy ray-curable pressure-sensitive adhesive generally contains an acrylic pressure-sensitive adhesive and an energy ray-polymerizable compound as main components. Usually, a crosslinking agent is further blended, and a photopolymerization initiator, a photosensitizer, or the like can also be blended as needed.

It is preferable to use the pressure-sensitive adhesive layer 31 that has a relatively larger adhesive force (Fa) to the image display element 45 (adherent) than the adhesive force (Fp) to the polarizing laminate of the surface protection film described above. . In addition, it is preferable to use a storage modulus or thickness of the pressure-sensitive adhesive layer 31 that is relatively larger than the storage modulus or thickness of the pressure-sensitive adhesive layer as a bonding layer included in the above-described polarizing laminate.

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

(release film)

The peeling film covers and protects the pressure-sensitive adhesive layer or supports the pressure-sensitive adhesive layer, and has a function as a separator that can be peeled off with respect to the pressure-sensitive adhesive layer. As a peeling film, the film by which release processing, such as silicone treatment, was given to the surface of the adhesive layer side of the base film is mentioned. Examples of the resin material constituting the base film include the same resin materials constituting the protective layer described above. The resin film may have a one-layer structure or may have a multilayer resin film having 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.

Information regarding the optical layered body may be displayed on the release film by printing or the like. As the information on the optical layered body, a display relating to the type of the polarizing layered body included in the optical layered body, a display indicating the direction of the absorption axis of the polarizing plate included in the polarizing layered body, and the like are exemplified.

(tape for peeling)

As the peeling tape, an adhesive tape having a pressure-sensitive adhesive layer formed on one side of a resin film can be used. As a resin film, what was illustrated as the resin film for surface protection films of a surface protection film can be used. The pressure-sensitive adhesive layer may be formed using the pressure-sensitive adhesive described in the pressure-sensitive adhesive layer 31 .

(substrate)

Although it does not specifically limit as an adherend to which an optical laminated body is bonded by the adhesive layer 31, For example, the image display element of a display device is mentioned. The image display element can be selected according to the type of display device. The image display element includes, for example, a display element such as a liquid crystal cell or an organic EL display element.

Example

Hereinafter, the present invention will be described more specifically by showing examples and comparative examples, but the present invention is not limited by these examples.

[Peel evaluation]

A release film was peeled off from the optical laminate obtained in Examples and Comparative Examples, and the optical laminate was bonded to a glass plate (holding table) with the exposed pressure-sensitive adhesive layer to prepare a test sample. A tape for peeling (Scotch Tape (registered trademark) (CT405-AP24), manufactured by Nichiban Co., Ltd.) was bonded and attached to the surface protection film on the surface of the optical layered body of the test sample. The peeling tape has a size of 24 mm in width and 100 mm in length, and in the planar view shape of the optical laminate of the test sample, the position of the center of the short side where the cutout is formed (assuming a square with no cutout) It was attached so as to be disposed on the surface of the surface protection film (Fig. 3 see.). In the comparative example, the peeling tape was affixed to the central position of one short side in the same manner as described above.

Of the peeling tape, the end on the gripping side opposite to the attaching end of the optical layered body is gripped with a chuck of a peeling device (Autograph AGS-50 NX, manufactured by Shimadzu Corporation), and the angle with respect to the surface direction of the optical layered body (peeling angle) was 180°, and the peeling speed was 300 mm/min, and a peeling test was conducted in which the peeling tape was pulled in a direction toward the other short side opposite to the short side to which the peeling tape was attached. 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 sample was evaluated as B. This peeling test was performed on 10 or 20 test samples, and the peeling defect rate was expressed by the following formula:

Peeling defect rate [%] = (number of times of evaluation B/number of peeling tests) × 100

was calculated based on

[Example 1]

(Manufacture of raw material laminate)

A linear polarization layer (8 μm in thickness) in which iodine was adsorbed and oriented was prepared on a polyvinyl alcohol-based resin film. A cyclic olefin resin (COP) film (thickness: 25 μm) in which a hard coat (HC) layer as a protective layer is formed on one side of the linear polarization layer through a water-based adhesive (hereinafter referred to as “25HC-COP film”) ) was bonded to the COP film side (opposite side to the HC layer side). On the HC layer of this protective layer, the acrylic adhesive layer side of a surface protection film (thickness: 53 μm) in which an acrylic adhesive layer (thickness: 15 μm) was formed on a polyester resin film (thickness: 38 μm) was bonded. A triacetyl cellulose (TAC) film (thickness: 20 µm) as a protective layer was bonded to the other side of the linear polarization layer via a water-based adhesive. Thus, a polarizing plate with a surface protection film (1) was obtained. The polarizing plate 1 with a surface protection film was obtained by stacking a surface protection film (polyester resin film, acrylic pressure-sensitive adhesive layer), a 25HC-COP film (HC layer, COP film), a linear polarization layer, and a TAC film in this order. .

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

(Manufacture of optical laminate)

Using the apparatus shown in FIG. 8, a laminate W obtained by laminating raw material laminates is prepared according to the procedure of the first step (above [a]) described above, and the second step (above [b] above) is prepared. ), the end faces corresponding to the four sides of the raw material laminate were polished. In addition, according to the procedure of the second step (above [b]) described above, one corner portion at one end of one short side of the raw material laminate was polished to obtain an optical laminate having one notch. . The corner portion is polished at a position of 0.3 mm (distance Laa and distance Lab in FIG. 1 ) in the short side direction and the long side direction from the vertex of the corner portion of the raw material laminate after polishing with respect to the end faces corresponding to the four sides. Set the first cutting start point (P1) and the second cutting start point (P2) in (refer to the first cutting start point (P1b) and the second cutting start point (P2b) in FIG. 1), the first cutting start point It grind|polished along the straight notch line which connects the start point P1 and the 2nd notch start point P2. In all of the above polishing, the relative movement speed of the multilayer body W and the rotary tool 60 was 2100 mm/min, and the rotational speed of the rotary tool was 5400 rpm. Peeling evaluation was performed about the obtained optical layered body. The results are shown in Table 1.

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

In addition, the adhesion between the acrylic pressure-sensitive adhesive layer side of the surface protection film and the HC layer side of the 25HC-COP film was measured by a 180° peel test using the peeling device described in the section of peel evaluation (peeling angle 180°, peeling speed 300 mm / minutes), it was 0.03 N/25 mm.

[Example 2]

An optical laminate was obtained in the same manner as in Example 1 except that two corner portions at both ends of one short side of the raw material laminate 1 were polished, respectively, and two notches were formed. As in Example 1, both of the two notches are the first notch start point P1 and the second notch start point P2 from the apex of the corner portion of the raw material laminate 1 after polishing of the end faces corresponding to the four sides. The distance to ) was 0.3 mm, respectively, and all cut lines connecting the first notch start point P1 and the second notch start point P2 were straight lines. Peel evaluation was performed about the optical layered body. The results are shown in Table 1.

[Example 3]

The distances from the vertices of the corners of the raw material laminate (raw material laminate after polishing of the end surfaces corresponding to the four sides) to the first cutting start point P1 and the second cutting start point P2 were each set to 0.2 mm. Other than that, an optical laminate was obtained in the same manner as in Example 2. Peel evaluation was performed about the optical layered body. The results are shown in Table 1.

[Example 4]

The distances from the vertices of the corners of the raw material laminate (raw material laminate after polishing of the end faces corresponding to the four sides) to the first cutting start point P1 and the second cutting start point P2 were each set to 0.1 mm. Other than that, an optical laminate was obtained in the same manner as in Example 2. Peel evaluation was performed about the optical layered body. The results are shown in Table 1.

[Example 5]

(Manufacture of raw material laminate)

Except for using a COP film having a thickness of 16 μm (hereinafter sometimes referred to as “16HC-COP film”) with a hard coat (HC) layer as a protective layer and not bonding a TAC film as a protective layer, A polarizing plate with a surface protection film (2) was obtained in the same procedure as in Example 1. In the polarizing plate 2 with a surface protection film, a surface protection film (polyester-based resin film, acrylic pressure-sensitive adhesive layer), a 16HC-COP film (HC layer, COP film), and a linear polarization layer were laminated in this order.

A pressure-sensitive adhesive layer 2 with a release film was prepared in which an adhesive layer (thickness: 10 μm) formed using an acrylic pressure-sensitive adhesive was formed on a release film (thickness: 38 μm). By using the polarizing plate with a surface protection film (2) instead of the polarizing plate with a surface protection film (1), the linear polarization layer side of the polarizing plate with a surface protection film (2) and the λ/4 plate of the retardation layer are connected to a bonding layer that is an adhesive layer. (thickness: 5 µm), and instead of the pressure-sensitive adhesive layer with a release film (1) on the positive C plate side of the retardation layer, the pressure-sensitive adhesive layer of the pressure-sensitive adhesive layer with a release film (2) is bonded to Example 1 and A raw material laminate (2) was obtained in the same manner.

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

(Manufacture of optical laminate)

Example 2, except that the raw material laminate 2 was used, the relative movement speed of the laminate W and the rotary tool 60 was 700 mm/min, and the rotational speed of the rotary tool 60 was 4800 rpm. An optical laminate was obtained in the same manner as described above. In the same procedure as in Example 1, the adhesion between the surface protection film and the peeling tape and the adhesion between the acrylic pressure-sensitive adhesive layer side of the surface protection film and the HC layer side of the 16HC-COP film were measured, respectively, 9 N / 25 mm and 0.03 N/25 mm.

[Example 6]

An optical laminate was obtained in the same procedure as in Example 5, except that only one corner portion at one end of one short side of the raw material laminate 2 was polished to form one notch. Peel evaluation was performed about the optical layered body. The results are shown in Table 1.

[Comparative Example 1]

An optical laminate was obtained in the same manner as in Example 1 except for not polishing the corners of the raw material laminate and not forming cutouts. Peel evaluation was performed about the optical layered body. The results are shown in Table 1.

[Comparative Example 2]

An optical laminate was obtained in the same manner as in Example 5, except that the corners of the raw material laminate were not polished and no cuts were formed. Peel evaluation was performed about the optical layered body. The results are shown in Table 1.

In each example and each comparative example, at the time of the peeling test, each layer constituting the optical laminate (25HC-COP film or 16HC-COP film, linear polarization layer, TAC film, adhesive layer, λ / 4 plate, bonding layer , Positive C plate, pressure-sensitive adhesive layer) and glass plate (holding table), no peeling was observed.

1, 1a, 1b: optical laminate, 10a, 10b, 10c, 10d: side, 10eb, 10ed: line, 11b, 11d: cutout, 15: rectangle, 15a: first side, 15b: second side, 15c : 3rd side, 15d: 4th side, 20: polarizing laminate, 21: polarizing plate, 22: retardation layer, 31: pressure-sensitive adhesive layer, 32: peeling film, 35: peeling tape, 41: surface protection film, 50 : support, 51: board, 52: frame, 53: rotary table, 54: cylinder, 55: jig, 60: rotary tool, Laa, Lab, Lba, Lbd: distance, Pab, Pda: vertex, P1b, P1d (P1 ): first cutout start point, P2b, P2d (P2): second cutout start point, W: laminate.

Claims (10)

An optical laminate comprising a surface protection film, a polarizing plate having a protective layer on one side or both sides of a linear polarization layer, and a pressure-sensitive adhesive layer in this order,
The surface protection film is disposed so as to be peelable from the light-polarizing laminate,
The thickness of the polarizing laminate is 120 μm or less,
The planar view shape of the optical laminate is a shape having at least one cutout portion in which one corner portion of a quadrangle is cut,
The cutout portion has a shape cut along a cutout line passing through a first cutout start point P1 and a second cutout start point P2 set on the first side and the second side constituting the vertex of the corner portion, respectively. have,
The first cutting start point P1 and the second cutting start point P2 are set so that a distance from the vertex is 0.1 mm or more and 0.5 mm or less, respectively. The optical stack according to claim 1 , wherein the quadrangle is a quadrangle. 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 an end face in the cutout portion of the optical laminate is a cutting surface by a rotary tool. The optical laminate according to any one of claims 1 to 4, wherein each of the four sides of the quadrangle has a length of 30 mm or more and 100 mm or less. The method according to any one of claims 1 to 5, wherein at least two of the notches are provided,
The optical laminate according to claim 1 , wherein the cutout portion is formed so as to cut two adjacent corner portions of the quadrangle, respectively. The optical laminate according to any one of claims 1 to 6, wherein the polarizing laminate has a retardation layer on one or both surfaces of the polarizing plate. The optical laminate according to any one of claims 1 to 7, further comprising a release film that can be peeled from the pressure-sensitive adhesive layer on the side opposite to the light-polarizing laminate side of the pressure-sensitive adhesive layer. A peeling method of peeling the surface protection film from the optical laminate according to any one of claims 1 to 8,
A step of bonding the optical laminate to an adherend with the pressure-sensitive adhesive layer;
A step of attaching a peeling tape to the surface of the optical layered body on the side of the surface protection film;
The process of peeling the said surface protection film from the said optical laminated body bonded to the said adherend by grabbing and raising the said peeling tape
The peeling method includes, wherein the attaching step is to attach the peeling tape so as to span one side where the cutout portion is formed at an end portion of the planar view shape of the optical layered body. The optical laminate according to claim 9, wherein the optical laminate is the optical laminate according to claim 6,
The peeling method of claim 1, wherein the one side to which the peeling tape is attached is a side on which the cutout portions are formed at both ends.

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