CN117471594A

CN117471594A - Optical laminate

Info

Publication number: CN117471594A
Application number: CN202310898671.3A
Authority: CN
Inventors: 永安智; 幡中伸行
Original assignee: Sumitomo Chemical Co Ltd
Current assignee: Sumitomo Chemical Co Ltd
Priority date: 2022-07-29
Filing date: 2023-07-20
Publication date: 2024-01-30

Abstract

An optical laminate comprising a liquid crystal polarizing plate formed using a polymerizable liquid crystal compound and a liquid crystal retardation layer is reduced in thickness and has excellent impact resistance. The optical laminate includes, in order, a protective layer, a liquid crystal polarizing plate, a 1 st lamination layer, a 1 st liquid crystal retardation layer, a 2 nd lamination layer, a 2 nd liquid crystal retardation layer, and a 3 rd lamination layer. The liquid crystal polarizing plate includes a cured layer of the 1 st liquid crystal composition containing a dichroic dye and a polymerizable liquid crystal compound. The 1 st bonding layer and the 2 nd bonding layer are both cured layers of the active energy ray-curable composition. The 1 st liquid crystal retardation layer and the 2 nd liquid crystal retardation layer each include a cured layer of the 2 nd liquid crystal composition containing a polymerizable liquid crystal compound.

Description

Optical laminate

Technical Field

The present invention relates to an optical laminate.

Background

As an organic EL display device, a flexible display device capable of bending or winding a display screen is known. In an organic EL display device, a circular polarizing plate in which a polarizing element and a phase difference element are laminated is used in order to suppress external light reflection. A circular polarizing plate applied to a flexible display device is required to reduce degradation of optical characteristics of a bent portion and to be less likely to crack due to bending (for example, patent document 1).

Prior art literature

Patent literature

Patent document 1: international publication No. 2016/158300

Disclosure of Invention

Problems to be solved by the invention

If the circularly polarizing plate is thinned, the thickness of the organic EL display device can be reduced, and the flexibility of the organic EL display device can be easily improved. Therefore, a liquid crystal retardation layer or the like formed of a liquid crystal compound may be used instead of the resin film as a retardation element constituting the circularly polarizing plate, thereby reducing the thickness of the circularly polarizing plate. However, when the circularly polarizing plate is thinned, the strength tends to be low, and therefore cracks tend to occur in the circularly polarizing plate due to an impact received from the outside, such as a touch panel operation performed on a display screen of the display device. In particular, when a liquid crystal polarizing plate formed of a liquid crystal compound is used as a polarizing element, it has been found that cracks tend to occur in a circularly polarizing plate.

An object of the present invention is to achieve excellent impact resistance while achieving a reduction in thickness in an optical laminate comprising a liquid crystal polarizing plate formed using a polymerizable liquid crystal compound and a liquid crystal retardation layer.

Means for solving the problems

The present invention provides the following optical layered body.

An optical laminate comprising, in order, a protective layer, a liquid crystal polarizing plate, a 1 st bonding layer, a 1 st liquid crystal retardation layer, a 2 nd bonding layer, a 2 nd liquid crystal retardation layer, and a 3 rd bonding layer,

The liquid crystal polarizing plate comprises a cured layer of a 1 st liquid crystal composition containing a dichroic dye and a polymerizable liquid crystal compound,

the 1 st bonding layer and the 2 nd bonding layer are all cured layers of active energy ray curable compositions,

the 1 st liquid crystal retardation layer and the 2 nd liquid crystal retardation layer each include a cured layer of a 2 nd liquid crystal composition containing a polymerizable liquid crystal compound.

The optical laminate according to item [ 2 ], wherein the 1 st lamination layer is a cured layer of the radical polymerizable adhesive composition.

The optical laminate according to [ 1 ] or [ 2 ], wherein the 2 nd lamination layer is a cured layer of the radical polymerizable adhesive composition.

The optical laminate according to any one of [ 1 ] to [ 3 ], wherein the thickness of each of the protective layer, the liquid crystal polarizing plate, the 1 st liquid crystal retardation layer, and the 2 nd liquid crystal retardation layer is less than 20.0 μm.

The optical laminate according to any one of [ 1 ] to [ 4 ], wherein the glass transition temperature of the 3 rd lamination layer is 25℃or lower.

The optical laminate according to any one of [ 1 ] to [ 5 ], wherein when the distance from the surface of the protective layer on the opposite side from the liquid crystal polarizer side to the surface of the 3 rd adhesive layer on the opposite side from the 2 nd liquid crystal retardation layer side is D1[ mu ] m,

The thickness D2[ mu ] m of the 3 rd bonding layer is 40% to 70% of D1.

The optical laminate according to any one of [ 1 ] to [ 6 ], further comprising an overcoat layer (protective layer 2) covering the surface of the liquid crystal polarizer on the 1 st lamination layer side.

Effects of the invention

According to the present invention, it is possible to provide an optical laminate which is excellent in impact resistance while achieving a reduction in thickness by providing a liquid crystal polarizer and a liquid crystal retardation layer formed using a polymerizable liquid crystal compound.

Drawings

Fig. 1 is a cross-sectional view schematically showing an example of an optical laminate according to an embodiment of the present invention.

Fig. 2 is a schematic diagram illustrating a method of bending test of the embodiment.

Fig. 3 is a schematic perspective view schematically showing an end face machining apparatus used in the example.

Description of the reference numerals

1 optical laminate, 10 polarizing plate, 11 protective layer, 15 liquid crystal polarizer, 18 overcoat layer (2 nd protective layer), 21 st liquid crystal retardation layer, 22 nd liquid crystal retardation layer, 31 st lamination layer, 32 nd lamination layer, 33 rd lamination layer, 38 spacer, 50 support, 51 substrate, 52 frame, 53 rotary table, 54 cylinder, 55 jig, 60 rotary tool, 500 test piece, 501, 502 jig, B grinding blade, R rotary shaft, W laminate.

Detailed Description

Hereinafter, preferred embodiments of the optical laminate will be described with reference to the accompanying drawings.

(optical laminate)

Fig. 1 is a cross-sectional view schematically showing an example of an optical laminate according to an embodiment of the present invention. As shown in fig. 1, the optical laminate 1 includes, in order, a protective layer 11, a liquid crystal polarizing plate 15, a 1 st bonding layer 31, a 1 st liquid crystal retardation layer 21, a 2 nd bonding layer 32, a 2 nd liquid crystal retardation layer 22, and a 3 rd bonding layer 33. The optical laminate 1 may further have an overcoat layer (2 nd protective layer) 18 covering the surface of the liquid crystal polarizing plate 15 on the 1 st lamination layer 31 side. In the optical laminate 1, the protective layer 11 and the liquid crystal polarizing plate 15 may constitute the polarizing plate 10 without the overcoat layer 18, and the protective layer 11, the liquid crystal polarizing plate 15, and the overcoat layer 18 may constitute the polarizing plate 10 with the overcoat layer 18. The polarizing plate 10 has a function of absorbing a polarized light component parallel to the absorption axis and transmitting a polarized light component orthogonal to the absorption axis. A spacer 38 that can be peeled off from the 3 rd bonding layer 33 can be bonded to the opposite side of the 3 rd bonding layer 33 from the 2 nd liquid crystal retardation layer 22 side of the optical laminate 1. The optical stack 1 and the spacer 38 constitute a spacer-equipped optical stack.

In the optical laminate 1, the 1 st bonding layer 31 is preferably in direct contact with the polarizing plate 10 and the 1 st liquid crystal retardation layer 21, the 2 nd bonding layer 32 is preferably in direct contact with the 1 st liquid crystal retardation layer 21 and the 2 nd liquid crystal retardation layer 22, and the 3 rd bonding layer 33 is preferably in direct contact with the 2 nd liquid crystal retardation layer 22. The 1 st adhesive layer 31 may be in direct contact with the liquid crystal polarizing plate 15 constituting the polarizing plate 10 or may be in direct contact with the overcoat layer 18 constituting the polarizing plate 10. In the polarizing plate 10, it is preferable that the protective layer 11 is in direct contact with the liquid crystal polarizing plate 15, and that the liquid crystal polarizing plate 15 is in direct contact with the overcoat layer 18.

The protective layer 11 may constitute the outermost surface of the optical laminate 1 on the observation side, and may cover and protect the surface of the liquid crystal polarizer 15. The surface of the protective layer 11 on the opposite side of the liquid crystal polarizer 15 side is usually a surface exposed to the atmosphere, a surface covered with a surface protective film (protective film) that can be peeled off from the surface of the protective layer 11, or a surface covered with an adhesive layer having a thickness of 50 μm or more for bonding the front panel. In other words, the protective layer 11 is formed by a layer existing in the protective layer 11 in a range from the surface of the liquid crystal polarizing plate 15 on the protective layer 11 side to the surface of the protective layer 11.

The protective layer 11 may have a single-layer structure or a multilayer structure. The protective layer 11 preferably comprises a resin layer. The protective layer 11 may include, for example, a part or all of a 1 st base material layer (described later), and the 1 st base material layer is coated with a 1 st liquid crystal composition (described later) for forming the liquid crystal polarizing plate 15. The details of the protective layer 11 will be described later.

The liquid crystal polarizing plate 15 includes a cured layer of the 1 st liquid crystal composition including a dichroic dye and a polymerizable liquid crystal compound. By making the liquid crystal polarizing plate 15 a cured layer of the 1 st liquid crystal composition, the thickness of the liquid crystal polarizing plate 15 can be reduced as compared with a polarizing plate in which a dichroic dye is adsorbed and aligned to a polyvinyl alcohol resin film, and therefore the optical laminate 1 can be thinned. The liquid crystal polarizing plate 15 may have a single-layer structure formed only of the cured product layer, or may have a multilayer structure including a 1 st alignment film for aligning a polymerizable liquid crystal compound (described later) contained in the 1 st liquid crystal composition in addition to the cured product layer. Details of the liquid crystal polarizing plate 15 will be described later.

The 1 st liquid crystal retardation layer 21 and the 2 nd liquid crystal retardation layer 22 each include a cured layer of the 2 nd liquid crystal composition containing a polymerizable liquid crystal compound. By making the 1 st liquid crystal retardation layer 21 and the 2 nd liquid crystal retardation layer 22 a cured layer of the 2 nd liquid crystal composition, the thickness of the 1 st liquid crystal retardation layer 21 and the 2 nd liquid crystal retardation layer 22 can be reduced as compared with a retardation layer using a resin film, and therefore the optical laminate 1 can be thinned. The 1 st liquid crystal retardation layer 21 and the 2 nd liquid crystal retardation layer 22 may have a single-layer structure formed only of the cured product layer, or may have a multilayer structure including a 2 nd alignment film for aligning the polymerizable liquid crystal compound in addition to the cured product layer. The 1 st liquid crystal retardation layer 21 and the 2 nd liquid crystal retardation layer 22 may include cured layers formed of the same 2 nd liquid crystal composition, or may include cured layers of different 2 nd liquid crystal compositions.

The 1 st bonding layer 31 and the 2 nd bonding layer 32 are each a cured product layer of an active energy ray-curable composition. In the optical laminate 1, the liquid crystal polarizing plate 15 is a cured layer of the 1 st liquid crystal composition, and the 1 st liquid crystal retardation layer 21 and the 2 nd liquid crystal retardation layer 22 are cured layers of the 2 nd liquid crystal composition. Therefore, the thickness of the liquid crystal polarizing plate 15, the 1 st liquid crystal retardation layer 21, and the 2 nd liquid crystal retardation layer 22 can be reduced, and the optical laminate 1 can be thinned, but the strength against an external impact is easily reduced. In particular, in an optical laminate in which the liquid crystal polarizing plate 15 as a cured layer of the 1 st liquid crystal composition and the 1 st liquid crystal retardation layer 21 and the 2 nd liquid crystal retardation layer 22 including a cured layer of the 2 nd liquid crystal composition are laminated, cracks are likely to occur in the optical laminate due to an impact resistance test (described later) in which a heavy object is dropped. Such cracks are unlikely to occur in a laminate in which a polarizing plate obtained by adsorbing a dichroic dye to a polyvinyl alcohol resin film and the 1 st liquid crystal retardation layer and the 2 nd liquid crystal retardation layer are laminated, and are considered to be a phenomenon peculiar to the case where the liquid crystal polarizing plate 15 includes a cured layer of the 1 st liquid crystal composition.

In the optical laminate 1, by making the 1 st lamination layer 31 and the 2 nd lamination layer 32 as cured layers of the active energy ray-curable composition as described above, a layer harder than a lamination layer (hereinafter also referred to as "adhesive layer") having a glass transition temperature of 25 ℃ or less can be formed. Accordingly, the occurrence of cracks in the liquid crystal polarizing plate 15, the 1 st liquid crystal retardation layer 21, and/or the 2 nd liquid crystal retardation layer 22 can be suppressed in the impact resistance test, and even when cracks occur, the size of the cracks can be reduced.

By making the 1 st bonding layer 31 and the 2 nd bonding layer 32 as cured layers of the active energy ray-curable composition, damage when a force is applied from the outside of the optical laminate 1 can be less likely to remain than in the case where one or both of them are adhesive layers. In particular, when the thickness of the protective layer 11 of the optical laminate 1 is small (for example, 15 μm or less), the 1 st bonding layer 31 and the 2 nd bonding layer 32 are preferably cured layers of the active energy ray-curable composition so as to prevent damage to the optical laminate 1.

The active energy ray-curable composition used to form the 1 st lamination layer 31 and/or the 2 nd lamination layer 32 is preferably a radical-polymerizable adhesive composition. That is, the 1 st bonding layer 31 and/or the 2 nd bonding layer 32 is preferably a cured layer of the radical polymerizable adhesive composition. More preferably, the 1 st bonding layer 31 and the 2 nd bonding layer 32 are both cured layers of the radical polymerizable adhesive composition. The radical polymerizable adhesive composition has a high rate of hardness increase by forming a crosslinked structure by a curing reaction, and can form a cured product layer having a sufficient hardness immediately after irradiation with active energy rays. In contrast, the curing reaction of the cationically polymerizable adhesive composition progresses slowly, and therefore it takes time to obtain sufficient hardness. As a result, the uncured component remains immediately after the irradiation of the active energy ray, and it tends to be difficult to obtain a cured layer having sufficient hardness immediately after the irradiation of the active energy ray, as compared with the cured layer of the radical polymerizable adhesive composition. Therefore, it is considered that the cured layer of the radical polymerizable adhesive composition is less likely to be deformed by a force applied from the outside immediately after curing than the cured layer of the cationic polymerizable adhesive composition, and that foreign matter bite marks are less likely to remain in the optical laminate 1.

The optical laminate 1 is generally manufactured in the form of a long body, and thus the layers bonded by the 1 st bonding layer 31 and the 2 nd bonding layer 32 are also long bodies. When such a long body is conveyed by using a bonding roller and a conveying roller, a foreign matter bite may be generated in the obtained optical laminate 1 by contact with these rollers. If the 1 st bonding layer 31 and/or the 2 nd bonding layer 32 are cured layers of the radical polymerizable adhesive composition as described above, sufficient hardness can be obtained even immediately after curing, and therefore deformation due to force received from the outside is less likely to occur, and occurrence of foreign matter bite in the optical laminate 1 can be suppressed.

In contrast, when the 1 st bonding layer 31 and the 2 nd bonding layer 32 are cured layers of the cationic adhesive composition, the cured layers are likely to be in contact with the bonding roller or the conveying roller without sufficiently performing the curing reaction. Therefore, as compared with the case where the cured product layer of the radical polymerizable adhesive composition is used for the 1 st lamination layer 31 and/or the 2 nd lamination layer 32, a foreign matter biting mark is likely to be generated in the optical laminate 1.

By using the cured product layer of the active energy ray-curable composition as the 1 st bonding layer 31 and the 2 nd bonding layer 32, the thickness of the 1 st bonding layer 31 and the 2 nd bonding layer 32 can be reduced as compared with the case of using an adhesive layer, and therefore, the optical laminate 1 can be further thinned. Details of the 1 st bonding layer 31 and the 2 nd bonding layer 32 will be described later.

The 3 rd bonding layer 33 may be a bonding layer for bonding the optical laminate 1 to a display element of a display device. The 3 rd lamination layer 33 is preferably a lamination layer having a glass transition temperature (hereinafter also referred to as "Tg") of 25 ℃ or less. The lamination layer having a Tg of 25 ℃ or less may be referred to as a so-called adhesive layer formed using an adhesive composition (pressure-sensitive adhesive). When Tg of the 3 rd bonding layer 33 is 25 ℃ or lower, the spacer 38 may be bonded to the opposite side of the 3 rd bonding layer 33 and the 2 nd liquid crystal retardation layer 22 side of the optical laminate 1. Details of the 3 rd lamination layer 33 will be described later.

As shown in fig. 1, when the distance from the surface of the protective layer 11 opposite to the liquid crystal polarizing plate 15 side to the surface of the 3 rd adhesive layer 33 opposite to the 2 nd liquid crystal retardation layer 22 side is D1[ μm ], the total thickness Dt [ μm ] of the layers (adhesive layers) having Tg of 25 ℃ or less among the 1 st adhesive layer 31, 2 nd adhesive layer 32, and 3 rd adhesive layer 33 is preferably 40% to 70%, more preferably 40% to 67%, or 42% to 67%, or 43% to 67%. In the optical laminate 1, the 3 rd lamination layer 33 is a layer (adhesive layer) capable of having a Tg of 25 ℃ or less, among the 1 st lamination layer 31, the 2 nd lamination layer 32, and the 3 rd lamination layer 33. Therefore, when Tg of the 3 rd lamination layer is 25 ℃ or lower, the total thickness Dt is equal to the thickness D2[ μm ] of the 3 rd lamination layer 33. In this case, the thickness D2 is preferably 40% to 70% of the distance D1, more preferably 40% to 67%, and may be 42% to 67%, or 43% to 67%.

The optical laminate 1 is easily bent due to the above-described reduction in thickness, and therefore can be suitably used for a flexible display device capable of bending and winding a display screen. When the optical laminate 1 is applied to a flexible display device and is bent, if the thickness D2 of the 3 rd bonding layer 33 is smaller than the above range, the 3 rd bonding layer 33 is easily broken by the expansion and contraction of the 3 rd bonding layer 33 accompanying the bending. On the other hand, if the thickness D2 of the 3 rd bonding layer 33 is larger than the above range, cracks tend to occur in the 1 st liquid crystal retardation layer 21 and/or the 2 nd liquid crystal retardation layer 22 during polishing of the optical laminate 1. When an impact of a working treatment is applied to the optical laminate 1, the 3 rd lamination layer 33 having a Tg of 25 ℃ or lower tends to be greatly deformed as the thickness is larger. It is considered that if the 3 rd bonding layer 33 is greatly deformed, the 1 st liquid crystal retardation layer 21 and/or the 2 nd liquid crystal retardation layer 22 are deformed together with the deformation, and therefore cracks are likely to occur in the 1 st liquid crystal retardation layer 21 and/or the 2 nd liquid crystal retardation layer 22.

In the optical laminate 1, the thicknesses of the protective layer 11, the liquid crystal polarizing plate 15, the 1 st liquid crystal retardation layer 21, and the 2 nd liquid crystal retardation layer 22 are preferably each less than 20.0 μm. The thickness of each of the protective layer 11, the liquid crystal polarizing plate 15, the 1 st liquid crystal retardation layer 21, and the 2 nd liquid crystal retardation layer 22 may be less than 20.0 μm, and each is independently preferably 15.0 μm or less, more preferably 10.0 μm or less, further preferably 5.0 μm or less, still more preferably less than 5.0 μm, particularly preferably 4.5 μm or less, and most preferably 4.0 μm or less, 3.5 μm or less. The thickness of the protective layer 11, the liquid crystal polarizing plate 15, the 1 st liquid crystal retardation layer 21, and the 2 nd liquid crystal retardation layer 22 is usually 0.01 μm or more, or may be 0.1 μm or more, independently of each other. When the thickness of each layer is within the above range, it is easy to suppress occurrence of unevenness in reflection color tone of a bent portion when the optical laminate 1 is repeatedly bent.

The thickness of the protective layer 11 may be in the above range, but is preferably 0.1 μm or more and less than 20.0 μm, more preferably 0.1 μm or more and 10.0 μm or less, still more preferably 0.1 μm or more and less than 5.0 μm, still more preferably 0.1 μm or more and 4.5 μm or less, and most preferably 0.1 μm or more and 4.0 μm or less.

The thickness of the liquid crystal polarizing plate 15 may be in the above range, but is preferably 0.1 μm or more and 10.0 μm or less, more preferably 0.3 μm or more and 5.0 μm or less, and still more preferably 0.5 μm or more and 3.0 μm or less.

The thickness of the 1 st liquid crystal retardation layer 21 and the 2 nd liquid crystal retardation layer 22 may be within the above-mentioned range, and may be independently preferably 0.1 μm or more and 10.0 μm or less, more preferably 0.3 μm or more and 5.0 μm or less, and still more preferably 0.3 μm or more and 3.0 μm or less.

The optical layered body 1 may be a circularly polarizing plate, and in this case, the optical layered body 1 may be used as an antireflection film.

(method for producing optical laminate)

The optical laminate 1 can be produced by laminating the protective layer 11, the liquid crystal polarizing plate 15, the 1 st lamination layer 31, the 1 st liquid crystal retardation layer 21, the 2 nd lamination layer 32, the 2 nd liquid crystal retardation layer 22, and the 3 rd lamination layer 33. The order of lamination of the layers is not particularly limited. For example, [ i ] may be obtained by stacking a laminate (phase difference body) obtained by stacking the 1 st liquid crystal retardation layer 21 and the 2 nd liquid crystal retardation layer 22 via the 2 nd lamination layer 32 via the 1 st lamination layer 31, and then stacking the 3 rd lamination layer 33, [ ii ] may be obtained by stacking the 1 st liquid crystal retardation layer 21 via the 1 st lamination layer 31, then stacking the 2 nd liquid crystal retardation layer 22 via the 2 nd lamination layer 32, and then stacking the 3 rd lamination layer 33.

(display device)

The optical layered body 1 can be applied to a display device. The display device includes an optical laminate 1 and a display element, and the optical laminate 1 is disposed on the observation side of the display element. The optical laminate 1 may be bonded to a display element using the 3 rd bonding layer 33.

The display device is not particularly limited, and examples thereof include display devices such as an organic electroluminescence (organic EL) display device, an inorganic electroluminescence (inorganic EL) display device, a liquid crystal display device, and an electroluminescence display device. When the optical laminate 1 is a circularly polarizing plate, it can be suitably used as an antireflection film for an organic EL display device. The optical layered body 1 can be suitably used for a flexible display device capable of bending and winding a display screen.

The display device can be used as mobile equipment such as smart phones, tablet computers and the like, televisions, digital photo frames, electronic billboards, measuring instruments or metering instruments, office equipment, medical equipment, electronic computer equipment and the like.

Details of each member constituting the optical laminate and the member for manufacturing each layer will be described below.

(polarizing plate)

The polarizing plate is a film including a liquid crystal polarizer, and is a film that performs an optical function of the liquid crystal polarizer. The polarizing plate may be a single liquid crystal polarizing plate, a laminate in which a liquid crystal polarizing plate and a protective layer are directly laminated, or a laminate in which a protective layer, a liquid crystal polarizing plate, and an overcoat layer (2 nd protective layer) are directly laminated.

The polarization properties of the polarizing plate can be measured using a spectrophotometer. For example, a device in which a prism polarizing plate is provided in a spectrophotometer may be used to measure the transmittance (T1) in the transmission axis direction (alignment vertical direction) and the transmittance (T2) in the absorption axis direction (alignment direction) in the visible light, that is, in the wavelength range of 380nm to 780nm by a two-beam method. The polarization performance in the visible light range can be calculated by calculating the individual transmittance and polarization degree at each wavelength using the following formulas (formula 1) and (formula 2), and then performing visibility correction by using the 2-degree field of view (C light source) of JIS Z8701, thereby calculating the individual transmittance (Ty) and the visibility correction polarization degree (Py) by the visibility correction. In addition, L is calculated from the same measured transmittance using the isochromatic function of the C light source ^＊ a ^＊ b ^＊ Chromaticity a in the (CIE) color system ^＊ B ^＊ The color tone of the polarizing plate alone (single color tone), the color tone of the polarizing plate arranged in parallel (parallel color tone), and the color tone of the polarizing plate arranged in orthogonal (orthogonal color tone) were thus obtained. a, a ^＊ B ^＊ The closer the value of (2) is to 0, the more neutral tone can be determined.

Monomer transmittance [% ] = (t1+t2)/2 (formula 1)

Degree of polarization [% ] = [ (T1-T2)/(t1+t2) ] x 100 (2)

The visibility correction polarization degree Py of the polarizing plate is usually 80% or more, preferably 90% or more, more preferably 95% or more, further preferably 98% or more, particularly preferably 99% or more, and if 99.9% or more, it can be suitably used for a liquid crystal display device. Increasing the visibility-corrected polarization Py of the polarizing plate is advantageous in improving the antireflection function of the optical laminate. If the visibility correction polarization degree Py is less than 80%, it may be difficult to perform a sufficient antireflection function when the optical laminate is used as an antireflection film.

The visibility of the polarizing plate increases as the visibility correction monomer transmittance Ty increases, but as the monomer transmittance becomes too large, the degree of polarization decreases as is apparent from the relationship between (formula 1) and (formula 2). Therefore, the visibility-correcting monomer transmittance Ty is preferably 30% or more and 60% or less, more preferably 35% or more and 55% or less, further preferably 40% or more and 50% or less, further preferably 40% or more and 45% or less. When the visibility correction monomer transmittance Ty is too large, the visibility correction polarization Py becomes too small, and in some cases, it is difficult to perform a sufficient antireflection function when the optical laminate is used as an antireflection film.

The polarizing plate can be obtained by [ i ] directly forming a liquid crystal polarizing plate on the 1 st base material layer as described later, using the 1 st base material layer as a protective layer, thereby obtaining [ ii ] using a material having a resin film and a surface treatment layer formed thereon as the 1 st base material layer, forming the liquid crystal polarizing plate on the surface treatment layer, and then removing the resin film contained in the 1 st base material layer by peeling, thereby obtaining the surface treatment layer as a protective layer. Alternatively, [ iii ] the 1 st base layer used in forming the liquid crystal polarizer may be peeled off and removed, and a protective layer may be laminated on the liquid crystal polarizer. In the case where the polarizing plate has an overcoat layer, the overcoat layer may be formed on the liquid crystal polarizing plate on the 1 st substrate layer.

(liquid Crystal polarizer)

The liquid crystal polarizer is a film having an absorption axis and a transmission axis orthogonal thereto, and absorbing a polarization component parallel to the absorption axis and transmitting a polarization component parallel to the transmission axis in the plane. The liquid crystal polarizing plate is a film having a structure in which a layer (cured product layer) containing a polymer of a polymerizable liquid crystal compound containing a dichroic dye is formed alone or in which the layer and an alignment film are formed in 2 layers. In the liquid crystal polarizing plate, the dichroic dye is aligned in one direction in the plane. The liquid crystal polarizing plate may be formed of a 1 st liquid crystal composition containing a polymerizable liquid crystal compound and a dichroic dye, and the dichroic dye and the polymerizable liquid crystal compound are uniaxially aligned to form a material including a layer (cured layer) containing a polymer of the polymerizable liquid crystal compound containing the dichroic dye. That is, the liquid crystal polarizer may exhibit a polarizing function by anisotropically absorbing light using a dichroic dye contained in a polymer of a polymerizable liquid crystal compound.

The liquid crystal polarizing plate including the cured product layer of the 1 st liquid crystal composition can be suitably used in, for example, a flexible display device from the viewpoint of being able to control the color tone arbitrarily, being able to be made thin to a large extent, and being able to have non-contractibility substantially without stretching relaxation due to heat.

The ratio (dichroic ratio; A1 (lambda)/A2 (lambda)) of the absorbance A1 (lambda) in the orientation direction to the absorbance A2 (lambda) in the direction perpendicular to the orientation plane of the liquid crystal polarizing plate with respect to light having a wavelength of lambda nm is preferably 7 or more, more preferably 20 or more, still more preferably 40 or more. The larger the value, the more excellent the absorption selectivity can be said to be a liquid crystal polarizing plate. The ratio is about 5 to 10 in the case of a cured product layer obtained by curing in a nematic liquid crystal phase, although it depends on the type of the dichroic dye.

By including 2 or more kinds of dichroic dyes having different absorption wavelengths in the liquid crystal polarizing plate, a liquid crystal polarizing plate having various hues can be produced, and a liquid crystal polarizing plate having absorption in the entire visible light range can be produced. By producing a liquid crystal polarizing plate having such absorption characteristics, various applications can be expanded.

The liquid crystal polarizing plate can be formed by coating the 1 st liquid crystal composition on the 1 st substrate layer, on which the 1 st alignment film is formed as needed, and aligning the dichroic dye contained in the 1 st liquid crystal composition. The liquid crystal polarizing plate may further include a 1 st alignment film in addition to the cured layer. The 1 st base material layer may be used as a protective layer as it is, or the resin film contained in the 1 st base material layer may be used as a protective layer, or the resin film may be peeled off and removed, and the surface treatment layer contained in the 1 st base material layer may be used as a protective layer. The 1 st orientation film can be peeled off together with the resin film. The resin film and the 1 st alignment film may be removed by laminating the liquid crystal polarizing plate with the 1 st liquid crystal retardation layer and the 2 nd liquid crystal retardation layer.

(1 st liquid crystal composition)

The 1 st liquid crystal composition is a composition for forming a liquid crystal polarizing plate, and may further contain additives such as a solvent, a leveling agent, a polymerization initiator, a sensitizer, a polymerization inhibitor, a crosslinking agent, a binder, and a reactive additive, in addition to the dichroic dye and the polymerizable liquid crystal compound. From the viewpoint of processability, the 1 st liquid crystal composition preferably contains a solvent and a leveling agent.

The polymerizable liquid crystal compound is a compound having at least 1 polymerizable group in a molecule and having liquid crystallinity. The polymerizable group means a group participating in polymerization reaction, and is preferably a photopolymerizable group. The photopolymerizable group herein means a group that can participate in polymerization reaction by using a living radical, an acid, or the like generated from a photopolymerization initiator described later. Examples of the polymerizable group include vinyl, vinyloxy, 1-chlorovinyl, isopropenyl, 4-vinylphenyl, acryloyloxy, methacryloyloxy, epoxyethyl, and oxetanyl groups. Among them, acryloyloxy, methacryloyloxy, ethyleneoxy, ethyleneoxide, and oxetanyl groups are preferable, and methacryloyloxy and acryloyloxy groups are more preferable. The liquid crystal may be a thermotropic liquid crystal or a lyotropic liquid crystal, and when mixed with a dichroic dye to be described later, the thermotropic liquid crystal is preferable. The polymerizable liquid crystal compound may be a monomer or a polymer obtained by polymerizing a dimer or more.

In the case where the polymerizable liquid crystal compound contained in the 1 st liquid crystal composition is a thermotropic liquid crystal, the compound may be a thermotropic liquid crystal compound exhibiting a nematic liquid crystal phase or a smectic liquid crystal phase. The liquid crystal state exhibited by the polymerizable liquid crystal compound is preferably a smectic phase from the viewpoint of obtaining a liquid crystal polarizing plate (cured product layer) having a large dichroic ratio, and is more preferably a higher order smectic phase from the viewpoint of improving performance. Among them, higher-order smectic liquid crystal compounds forming a smectic B phase, a smectic D phase, a smectic E phase, a smectic F phase, a smectic G phase, a smectic H phase, a smectic I phase, a smectic J phase, a smectic K phase or a smectic L phase are more preferable, and higher-order smectic liquid crystal compounds forming a smectic B phase, a smectic F phase or a smectic I phase are more preferable. If the liquid crystal phase formed by the polymerizable liquid crystal compound is these higher order smectic phases, a liquid crystal polarizer (cured layer) having high polarization performance can be produced. In addition, in the case of the optical fiber, In the case of a liquid crystal polarizing plate (cured product layer) having such a high polarizing performance, bragg peaks derived from higher-order structures such as hexagonal phase and crystalline phase can be obtained in an X-ray diffraction measurement. The Bragg peak is a peak derived from a molecular oriented periodic structure, and the periodic interval is obtainedIs a layer of (c). From the viewpoint of obtaining higher polarization characteristics, a polymer containing a polymerizable liquid crystal compound in which the polymerizable liquid crystal compound is oriented in a smectic phase is preferable as the cured layer included in the liquid crystal polarizer.

As the polymerizable liquid crystal compound contained in the 1 st liquid crystal composition, 1 kind may be used alone, or 2 or more kinds may be used in combination. The content of the polymerizable liquid crystal compound in the 1 st liquid crystal composition is preferably 40% by mass or more and 99.9% by mass or less, more preferably 60% by mass or more and 99% by mass or less, and still more preferably 70% by mass or more and 99% by mass or less, relative to the solid content of the 1 st liquid crystal composition. When the content of the polymerizable liquid crystal compound is within the above range, the orientation of the polymerizable liquid crystal compound tends to be high. In the present specification, the term "solid component" means the total amount of components after the solvent is removed from the 1 st liquid crystal composition.

The dichroic dye is a dye having a property that the absorbance in the long axis direction of the molecule is different from the absorbance in the short axis direction. The dichroic dye preferably has a property of absorbing visible light, and more preferably has an absorption maximum wavelength (λmax) in the range of 380 to 680 nm. Examples of such a dichroic dye include acridine dye, oxazine dye, cyanine dye, naphthalene dye, azo dye, and anthraquinone dye, and among them, azo dye is preferable. Examples of the azo dye include monoazo dye, disazo dye, trisazo dye, tetrazo dye, stilbene azo dye, and the like, and preferably disazo dye and trisazo dye. The dichroic dye may be used alone or in combination, but in order to obtain absorption in the entire visible light range, it is preferable to use 2 or more dichroic dyes in combination, and it is more preferable to use 3 or more dichroic dyes in combination.

Examples of the azo dye include compounds represented by the formula (Da).

T ¹ -A ¹ (-N＝N-A ² ) _p -N＝N-A ³ -T ² (Da)

In the formula (Da) of the formula (I),

A ¹ 、A ² a is a ³ Independently of each other, represents a 1, 4-phenylene group which may have a substituent, a naphthalene-1, 4-diyl group which may have a substituent, a phenyl benzoate group which may have a substituent, a 4,4' -stilbene group which may have a substituent, a 2-valent heterocyclic group which may have a substituent,

T ¹ T and T ² Represents an electron withdrawing group or an electron donating group, and is located at a position substantially 180 ° with respect to the azo bond plane.

p represents an integer of 0 to 4, and when p is 2 or more, each A ² May be the same as or different from each other.

In the range showing absorption in the visible light region, -n=n-bonds may be replaced with-c=c-, -COO-, -NHCO-, -n=ch-bonds. ]

The content of the dichroic dye contained in the 1 st liquid crystal composition (the total amount thereof in the case of containing a plurality of types) is usually 1 to 60 parts by mass or less, preferably 1 to 40 parts by mass or less, more preferably 1 to 20 parts by mass, per 100 parts by mass of the polymerizable liquid crystal compound, from the viewpoint of obtaining good light absorption characteristics. If the content of the dichroic dye is less than the above range, the light absorption is insufficient, and sufficient polarization performance cannot be obtained, and if it is more than the above range, the alignment of liquid crystal molecules may be inhibited.

The 1 st liquid crystal composition may contain a solvent. Since the viscosity of the polymerizable liquid crystal compound is generally high, the liquid crystal composition 1 dissolved in a solvent is prepared, and thus the coating becomes easy, and as a result, the cured product layer of the liquid crystal polarizer is often easily formed. The solvent is preferably a solvent capable of completely dissolving the polymerizable liquid crystal compound, and is preferably a solvent inactive to the polymerization reaction of the polymerizable liquid crystal compound.

Examples of the solvent include alcohol solvents such as methanol, ethanol, ethylene glycol, isopropanol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, and propylene glycol monomethyl ether; ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ -butyrolactone, propylene glycol methyl ether acetate, and ethyl lactate; ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone, and methyl isobutyl ketone; aliphatic hydrocarbon solvents such as pentane, hexane and heptane; aromatic hydrocarbon solvents such as toluene and xylene; nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran and dimethoxyethane; chlorine-containing solvents such as chloroform and chlorobenzene; amide solvents such as dimethylacetamide, dimethylformamide, N-methyl-2-pyrrolidone, and 1, 3-dimethyl-2-imidazolidinone. These solvents may be used alone or in combination of 2 or more.

The content of the solvent is preferably 50 to 98% by mass relative to the total amount of the 1 st liquid crystal composition. In other words, the content of the solid component in the 1 st liquid crystal composition is preferably 2 to 50% by mass, more preferably 5 to 30% by mass.

The 1 st liquid crystal composition may contain a leveling agent. The leveling agent is an additive having a function of adjusting the fluidity of the composition and flattening a film obtained by coating the composition. Examples of the leveling agent include organomodified silicone oil-based leveling agents, polyacrylate-based leveling agents, and perfluoroalkyl-based leveling agents. Among them, a polyacrylate-based leveling agent and a perfluoroalkyl-based leveling agent are preferable.

When the 1 st liquid crystal composition contains a leveling agent, the content of the leveling agent is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 3 parts by mass, per 100 parts by mass of the polymerizable liquid crystal compound.

The 1 st liquid crystal composition may contain a polymerization initiator. The polymerization initiator is a compound capable of initiating a polymerization reaction of a polymerizable liquid crystal compound or the like. As the polymerization initiator, a photopolymerization initiator that generates a living radical by the action of light is preferable from the standpoint of not depending on the phase state of the thermotropic liquid crystal.

The photopolymerization initiator may be any known photopolymerization initiator as long as it is a compound capable of initiating polymerization reaction of the polymerizable liquid crystal compound. Specifically, a photopolymerization initiator capable of generating a living radical or an acid by the action of light is exemplified, and among them, a photopolymerization initiator capable of generating a radical by the action of light is preferable. The photopolymerization initiator may be used singly or in combination of two or more.

As the photopolymerization initiator, a known photopolymerization initiator can be used, and as the photopolymerization initiator generating active radicals, for example, a self-cleaving benzoin compound, acetophenone compound, hydroxyacetophenone compound, α -aminoacetophenone compound, oxime ester compound, acylphosphine oxide compound, azo compound, etc., a hydrogen abstraction benzophenone compound, alkylbenzene ketone compound, benzoin ether compound, benzil ketal compound, dibenzosuberone compound, anthraquinone compound, xanthone compound, thioxanthone compound, haloacetophenone compound, dialkoxyacetophenone compound, halobisimidazole compound, halotriazine compound, triazine compound, etc. can be used. As the photopolymerization initiator for generating an acid, iodonium salts, sulfonium salts, and the like can be used. From the viewpoint of excellent reaction efficiency at low temperatures, a photopolymerization initiator selected from cleavage type is preferable, and acetophenone-based compounds, hydroxyacetophenone-based compounds, α -aminoacetophenone-based compounds, and oxime ester-based compounds are particularly preferable.

The content of the polymerization initiator in the 1 st liquid crystal composition may be appropriately adjusted depending on the kind of the polymerizable liquid crystal compound and the amount thereof, but is usually 0.1 to 30 parts by mass, preferably 0.5 to 10 parts by mass, more preferably 0.5 to 8 parts by mass, relative to 100 parts by mass of the content of the polymerizable liquid crystal compound. When the content of the polymerization initiator is within the above range, polymerization can be performed without disturbing the orientation of the polymerizable liquid crystal compound.

The 1 st liquid crystal composition may contain a sensitizer. As the sensitizer, a photosensitizer is preferable. When the 1 st liquid crystal composition contains a sensitizer, the polymerization reaction of the polymerizable liquid crystal compound contained in the 1 st liquid crystal composition can be further promoted. The amount of the sensitizer to be used is preferably 0.1 to 30 parts by mass based on 100 parts by mass of the content of the polymerizable liquid crystal compound.

From the viewpoint of stably conducting the polymerization reaction, the 1 st liquid crystal composition may contain a polymerization inhibitor. The polymerization inhibitor can control the progress of the polymerization reaction of the polymerizable liquid crystal compound. In the case where the 1 st liquid crystal composition contains a polymerization inhibitor, the content of the polymerization inhibitor is preferably 0.1 to 30 parts by mass relative to 100 parts by mass of the content of the polymerizable liquid crystal compound.

(protective layer)

The protective layer has a function of protecting the surface of the liquid crystal polarizer. The liquid crystal polarizer and the protective layer are directly laminated to each other. The term "direct lamination" as used herein includes a method of laminating a protective layer on a liquid crystal polarizer by self-adhesion of the protective layer and a method of laminating a protective layer on a liquid crystal polarizer by curing, if necessary, a 1 st liquid crystal composition for forming a cured layer of a liquid crystal polarizer coated on a protective layer on which a 1 st alignment film is formed. For the protective layer, a surface activation treatment (for example, corona treatment) may be applied to improve adhesion to the liquid crystal polarizer, or a thin layer such as a primer layer (also referred to as an easy-to-adhere layer) may be formed.

The protective layer may be a 1 st base material layer for forming a liquid crystal polarizing plate, or may be a layer including a part of the 1 st base material layer. The protective layer may have a single-layer structure or a multilayer structure. The protective layer preferably comprises a resin layer. The resin layer may be a resin film and/or a surface treatment layer.

As the resin film, for example, a film excellent in transparency, mechanical strength, thermal stability, water blocking property, isotropy, stretchability, and the like can be used. The resin film may be a thermoplastic resin film. Specific examples of the resin constituting such a resin film include cellulose resins such as triacetyl cellulose; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polyether sulfone resin; polysulfone-based resin; a polycarbonate resin; polyamide resins such as nylon and aromatic polyamide; polyimide resin; a chain polyolefin resin such as polyethylene, polypropylene, and an ethylene-propylene copolymer; cyclic polyolefin resins having a cyclic or norbornene structure (also referred to as norbornene resins); a (meth) acrylic resin such as polymethyl methacrylate; polyarylate-based resins; a polystyrene resin; polyvinyl alcohol resin, and mixtures thereof. The resin film of this material can be easily obtained from the market. The resin may be a thermosetting resin such as a (meth) acrylic resin, a urethane (meth) acrylic resin, an epoxy resin, or a silicone resin, or an ultraviolet curable resin. In the present specification, the term "(meth) acrylic" means at least one of acrylic and methacrylic. The same applies to (meth) acryl and the like.

Examples of the chain polyolefin resin include homopolymers of chain olefins such as polyethylene resins (polyethylene resins as homopolymers of ethylene and copolymers mainly composed of ethylene) and polypropylene resins (polypropylene resins as homopolymers of propylene and copolymers mainly composed of propylene), and copolymers containing 2 or more chain olefins.

The cyclic polyolefin resin is a generic term for resins polymerized by using a cyclic olefin as a polymerization unit. Specific examples of the cyclic polyolefin resin include a ring-opened (co) polymer of a cyclic olefin, an addition polymer of a cyclic olefin, a copolymer (typically, a random copolymer) of a cyclic olefin and a chain olefin such as ethylene or propylene, a graft polymer obtained by modifying the copolymer with an unsaturated carboxylic acid or a derivative thereof, and a hydrogenated product thereof. Among them, a norbornene resin using a norbornene monomer such as norbornene and polycyclic norbornene monomer as the cyclic olefin is preferably used.

The polyester resin is a resin having an ester bond in the main chain, and is usually a polycondensate of a polycarboxylic acid or a derivative thereof and a polyhydric alcohol. Examples thereof include terephthalic acid, isophthalic acid, dimethyl terephthalate, and dimethyl naphthalate. Examples of the polyol that can be used include 2-membered diols such as ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, and cyclohexanedimethanol.

The cellulose ester resin is an ester of cellulose and a fatty acid. Specific examples of the cellulose ester-based resin include cellulose triacetate, cellulose diacetate, cellulose tripropionate, and cellulose dipropionate. Further, there are exemplified a copolymer having a plurality of polymerization units constituting these cellulose ester resins, and a resin in which a part of the hydroxyl groups is modified with other substituents. Among them, cellulose triacetate (triacetyl cellulose) is particularly preferable.

The (meth) acrylic resin is a resin having a compound having a (meth) acryloyl group as a main constituent monomer. Specific examples of the (meth) acrylic resin include poly (meth) acrylates such as polymethyl methacrylate; methyl methacrylate- (meth) acrylic acid copolymer; methyl methacrylate- (meth) acrylate copolymers; methyl methacrylate-acrylate- (meth) acrylic acid copolymers; methyl (meth) acrylate-styrene copolymer (MS resin, etc.); copolymers of methyl methacrylate and compounds having alicyclic hydrocarbon groups (e.g., methyl methacrylate-cyclohexyl methacrylate copolymers, methyl methacrylate- (meth) norbornyl acrylate copolymers, etc.).

The polycarbonate resin includes a polymer obtained by bonding monomer units via a carbonate group. The polycarbonate resin may be a resin called a modified polycarbonate, a copolycarbonate, or the like, in which the polymer skeleton is modified. Details of the polycarbonate resin are described in, for example, japanese patent application laid-open No. 2012-31370.

The protective layer can be produced by stretching the resin film (thermoplastic resin film). The stretching treatment includes uniaxial stretching, biaxial stretching, and the like. Examples of the stretching direction include a mechanical flow direction (MD) of an unstretched film, a direction (TD) perpendicular thereto, and a direction oblique to the mechanical flow direction (MD).

The protective layer is disposed on the viewing side with respect to the liquid crystal polarizer, and thus may include a resin film and a surface treatment layer provided on the surface of the resin film in order to impart desired surface optical characteristics or other features. Alternatively, the protective layer may contain not a resin film but a surface treatment layer as a resin layer. When the protective layer contains the surface-treated layer without containing the resin film, for example, the protective layer as the surface-treated layer may be laminated on the liquid crystal polarizing plate as shown below. First, a surface treatment film having a surface treatment layer formed on a release layer is prepared by performing a release treatment for forming the release layer on the surface of the resin film on the side where the surface treatment layer is formed by coating with a release agent or the like. Then, the surface treatment film is laminated on the liquid crystal polarizer, the laminated body of the liquid crystal polarizer and the 1 st liquid crystal phase difference layer, or the laminated body of the liquid crystal polarizer and the 1 st liquid crystal phase difference layer and the 2 nd liquid crystal phase difference layer, and then the resin film is peeled off. Thus, as the protective layer, an optical laminate including the surface-treated layer without including the resin film can be obtained.

Examples of the surface treatment layer include a hard coat layer, an antiglare layer, an antireflection layer, an antistatic layer, an antifouling layer, and an anti-blocking layer. The surface treatment layer may be formed on the surface of the resin film by coating or the like or a release layer formed on the resin film, and when the protective layer contains the resin film, the surface treatment layer may be formed by modifying the surface of the resin film or the like.

The method for forming the surface treatment layer is not particularly limited, and a known method can be used. The surface treatment layer may be formed on one surface or both surfaces of the resin film.

The hard coat layer has a function of improving the surface hardness of the protective layer, and is provided for the purpose of preventing scratches on the surface, and the like. By forming a hard coat layer on the resin film, the hardness and scratch resistance of the protective layer can be improved. The hard coat layer is preferably in JIS K5600-5-4: 1999 "general test method for coatings-section 5: mechanical properties of the coating film-section 4: the pencil hardness test (measured by placing an optical film having a hard coating layer on a glass plate) specified in scratch hardness (pencil method) "shows H or a value harder than H.

The hard coat layer may contain various fillers as required for the purpose of adjusting the refractive index, improving the flexural modulus, stabilizing the volume shrinkage, and improving the heat resistance, antistatic property, antiglare property, and the like. The hard coat layer may contain additives such as antioxidants, ultraviolet absorbers, light stabilizers, antistatic agents, leveling agents, and defoaming agents.

(outer coating)

The polarizing plate may have an overcoat layer (2 nd protective layer) covering the 1 st liquid crystal retardation layer-side surface of the liquid crystal polarizing plate. The overcoat layer can be formed by coating a material (composition) constituting the overcoat layer, such as a photocurable resin or a water-soluble polymer, on the surface of the liquid crystal polarizer, and drying or curing the material. Examples of the photocurable resin include (meth) acrylic resins, urethane resins, (meth) acrylic urethane resins, epoxy resins, silicone resins, and the like. Examples of the water-soluble polymer include poly (meth) acrylamide polymers; polyvinyl alcohol and vinyl alcohol polymers such as ethylene-vinyl alcohol copolymer, ethylene-vinyl acetate copolymer, and (meth) acrylic acid or acid anhydride-vinyl alcohol copolymer; carboxyvinyl polymers; polyvinylpyrrolidone; starches; sodium alginate; polyethylene oxide polymers, and the like.

The thickness of the overcoat layer is usually 0.1 μm or more and 10.0 μm or less, preferably 5.0 μm or less, more preferably 3.0 μm or less. When the thickness of the overcoat layer is 10 μm or more, the reflection color unevenness at the bent portion is easily noticeable in the bending property test, and when it is less than 0.1 μm, the function of preventing pigment diffusion is easily impaired in a high temperature environment.

(1 st liquid Crystal phase-difference layer and 2 nd liquid Crystal phase-difference layer)

The 1 st liquid crystal retardation layer and the 2 nd liquid crystal retardation layer are films exhibiting retardation in the in-plane or thickness direction, and are layers (cured product layers) of a polymer containing a polymerizable liquid crystal compound, or films composed of 2 layers as the layers and an alignment film. The 1 st liquid crystal retardation layer and the 2 nd liquid crystal retardation layer comprise cured layers of the 2 nd liquid crystal composition containing a polymerizable liquid crystal compound. The 1 st liquid crystal retardation layer and/or the 2 nd liquid crystal retardation layer may each contain a 2 nd alignment film. The 2 nd liquid crystal composition for forming the 1 st liquid crystal retardation layer 21 and the 2 nd liquid crystal composition for forming the 2 nd liquid crystal retardation layer 22 may be the same as each other or may be different from each other.

The 1 st liquid crystal retardation layer and the 2 nd liquid crystal retardation layer are generally formed by coating a 2 nd liquid crystal composition on a 2 nd alignment film formed on a 2 nd base layer, and polymerizing a polymerizable liquid crystal compound contained in the 2 nd liquid crystal composition. The 1 st liquid crystal retardation layer and the 2 nd liquid crystal retardation layer generally include a layer obtained by curing a polymerizable liquid crystal compound in a state where alignment occurs, and in order to generate a retardation in a plane, a cured layer obtained by polymerizing a polymerizable group of the polymerizable liquid crystal compound in a state where the polymerizable liquid crystal compound is aligned in a horizontal direction with respect to the 2 nd substrate layer is required. In this case, the liquid crystal retardation layer may be a positive a plate when the polymerizable liquid crystal compound is a rod-like liquid crystal compound, and may be a negative a plate when the polymerizable liquid crystal compound is a discotic liquid crystal compound.

In order to realize the antireflection function of the optical laminate to a high degree, the combination of the 1 st liquid crystal retardation layer and the 2 nd liquid crystal retardation layer may have a λ/4 plate function (i.e., a pi/2 retardation function) in the entire visible light range. The 1 st liquid crystal retardation layer or the 2 nd liquid crystal retardation layer included in the optical laminate is preferably an inverse wavelength dispersive λ/4 layer. The 1 st liquid crystal retardation layer and the 2 nd liquid crystal retardation layer are preferably composed of 2 or more liquid crystal retardation layers having different alignment. Examples of the combination of 2 or more liquid crystal retardation layers include a combination of a liquid crystal retardation layer having a positive wavelength dispersion λ/2 plate function (i.e., a pi retardation function) (hereinafter also referred to as "λ/2 layer") and a liquid crystal retardation layer having a positive wavelength dispersion λ/4 plate function (i.e., a pi retardation function) (hereinafter also referred to as "λ/4 layer"). Alternatively, from the viewpoint of compensating the antireflection function in the oblique direction, one of the 1 st liquid crystal retardation layer and the 2 nd liquid crystal retardation layer may be a layer having anisotropy in the thickness direction (positive C plate) and the other may be a layer having inverse wavelength dispersibility λ/4. The 1 st liquid crystal retardation layer and the 2 nd liquid crystal retardation layer may each be in an oblique alignment state or in a cholesteric alignment state.

When the combination of the 1 st liquid crystal retardation layer and the 2 nd liquid crystal retardation layer is adjusted to have a λ/4 plate function in the entire visible light range, the retardation body including the 1 st liquid crystal retardation layer and the 2 nd liquid crystal retardation layer preferably satisfies the optical characteristics shown in the following formula (1) with respect to the light having the wavelength λ [ nm ], that is, re (λ), and preferably satisfies the optical characteristics shown in the following formulas (2) and (3). The retardation body is a laminated film in which a plurality of retardation plates are laminated, and is a laminated film that exhibits a retardation in the in-plane or thickness direction based on the plurality of laminated retardation plates. The retardation plate is a film including the 1 st liquid crystal retardation layer or the 2 nd liquid crystal retardation layer, and is a film exhibiting an optical function as the 1 st liquid crystal retardation layer or the 2 nd liquid crystal retardation layer.

100nm＜Re(550)＜160nm (1)

Re(450)/Re(550)≤1.0 (2)

1.00≤Re(650)/Re(550) (3)

[ in the formulae (1) to (3),

re (450) represents the in-plane phase difference value of the phase difference body for light with the wavelength of 450nm,

re (550) represents the in-plane phase difference value of the retardation body for light having a wavelength of 550nm,

re (650) represents the in-plane phase difference value of the phase difference body for light with a wavelength of 650 nm. ]

If "Re (450)/Re (550)" of the above formula (2) is larger than 1.0, light leakage on the short wavelength side of the optical laminate including the retardation body becomes large. The "Re (450)/Re (550)" is preferably 0.7 or more and 1.0 or less, more preferably 0.80 or more and 0.95 or less, still more preferably 0.80 or more and 0.92 or less, and particularly preferably 0.82 or more and 0.88 or less. The value of "Re (450)/Re (550)" can be arbitrarily adjusted by adjusting the mixing ratio of the polymerizable liquid crystal compound in the 2 nd liquid crystal composition, the lamination angle of the 1 st liquid crystal retardation layer and the 2 nd liquid crystal retardation layer, and the phase difference value thereof.

The in-plane phase difference values of the 1 st liquid crystal phase difference layer and the 2 nd liquid crystal phase difference layer can be adjusted by using the thicknesses of the two liquid crystal phase difference layers. Since the in-plane phase difference value is determined by the following equation (4), Δn (λ) and film thickness d may be adjusted to obtain a desired in-plane phase difference value (Re (λ)). The thickness of the 1 st liquid crystal retardation layer and the 2 nd liquid crystal retardation layer is preferably 0.5 μm or more and 5 μm or less, more preferably 1 μm or more and 3 μm or less, respectively. The thicknesses of the 1 st liquid crystal retardation layer and the 2 nd liquid crystal retardation layer can be measured by an interferometer film thickness meter, a laser microscope, or a probe film thickness meter, respectively. The Δn (λ) depends on the molecular structure of a polymerizable liquid crystal compound described later.

Re(λ)＝d×Δn(λ) (4)

In the formula (4) of the present invention,

re (lambda) represents the in-plane phase difference value of the liquid crystal retardation layer at wavelength lambda nm,

d represents the thickness of the liquid crystal retardation layer,

delta n (lambda) represents the birefringence at wavelength lambda nm. ]

When a combination of a positive wavelength dispersive λ/2 layer and a positive wavelength dispersive λ/4 layer is used as a phase difference body that is adjusted to have a λ/4 plate function in the entire visible light range, a layer having optical characteristics represented by the following formulas (1), (6) and (7) and a layer having optical characteristics represented by the following formulas (5) to (7) may be combined in a specific slow axis relationship.

100nm＜Re(550)＜160nm (1)

200nm＜Re(550)＜320nm (5)

Re(450)/Re(550)≥1.00 (6)

1.00≥Re(650)/Re(550) (7)

In the formulae (1) and (5) to (7),

As a method of combining the λ/2 layer and the λ/4 layer, known methods described in japanese patent application laid-open publication No. 2015-163935, WO2013/137464, and the like are mentioned. From the viewpoint of viewing angle compensation, it is preferable to use a λ/2 layer formed of a 2 nd liquid crystal composition containing a discotic polymerizable liquid crystal compound and a λ/4 layer formed of a 2 nd liquid crystal composition containing a rod-like polymerizable liquid crystal compound.

The positive C plate is not particularly limited as long as it is a layer having anisotropy in the thickness direction, and has optical characteristics represented by the following formula (8) when no oblique alignment or no cholesteric alignment is performed.

nx≈ny＜nz (8)

In the formula (8),

nx represents the principal refractive index at a wavelength lambda nm in the face of the positive C plate.

ny represents the refractive index of the positive C plate at the wavelength lambda nm in the direction orthogonal to nx in the same plane as nx.

nz (lambda) represents the refractive index at the wavelength lambda nm in the thickness direction of the positive C plate.

In the case where nx≡ny, nx may be set as the refractive index in any direction within the plane of the positive C plate. ]

The phase difference Rth (550) in the thickness direction at the wavelength 550nm of the positive C plate is usually in the range of-170 nm to-10 nm, preferably in the range of-150 nm to-20 nm, more preferably in the range of-100 nm to-40 nm. When the phase difference in the thickness direction is within this range, the antireflection property from the oblique direction can be further improved.

The positive C plate is preferably formed of a 2 nd liquid crystal composition containing a rod-like polymerizable liquid crystal compound.

The 1 st liquid crystal retardation layer and the 2 nd liquid crystal retardation layer may be used without any particular limitation as long as they are configured to have an antireflection function, in addition to the above-described configuration, in which tilt alignment and cholesteric alignment are performed. Examples of such a constitution include known constitution described in WO2021/060378, WO2021/132616 and WO 2021/132624.

(2. Liquid Crystal composition)

The 2 nd liquid crystal composition is a composition for forming a 1 st liquid crystal retardation layer and a 2 nd liquid crystal retardation layer. The 2 nd liquid crystal composition may further contain additives such as solvents, leveling agents, polymerization initiators, sensitizers, polymerization inhibitors, crosslinking agents, adhesion agents, and reactive additives. From the viewpoint of processability, the 2 nd liquid crystal composition preferably contains a solvent and a leveling agent. The additive may be the additive described in the 1 st liquid crystal composition, and the content of the additive in the 2 nd liquid crystal composition may be the content of the range described in the 1 st liquid crystal composition.

The polymerizable liquid crystal compound contained in the 2 nd liquid crystal composition is a liquid crystal compound having at least 1 polymerizable group, particularly a photopolymerizable group, in a molecule, and as the polymerizable liquid crystal compound, for example, a conventionally known polymerizable liquid crystal compound in the field of retardation films can be used. The liquid crystal property may be a thermotropic liquid crystal or a lyotropic liquid crystal, but the thermotropic liquid crystal is preferable in view of being capable of precise film thickness control. The phase-ordered structure of the thermotropic liquid crystal may be a nematic liquid crystal or a smectic liquid crystal. The liquid crystal may be a rod-shaped liquid crystal or a discotic liquid crystal. The polymerizable liquid crystal compound may be used singly or in combination of two or more.

As the polymerizable liquid crystal compound of the λ/4 layer for obtaining the inverse wavelength dispersibility, a liquid crystal having a mesogenic structure in a T-shape or H-shape, which further has birefringence in a direction perpendicular to the molecular long axis direction, is preferable from the viewpoint of exhibiting the inverse wavelength dispersibility, and a T-shaped liquid crystal is more preferable from the viewpoint of obtaining a stronger dispersion, and specifically, a compound represented by the following formula (I) is exemplified as the structure of the T-shaped liquid crystal.

[ chemical 1]

/>

In the formula (I) of the formula (I),

ar represents a divalent aromatic group which may have a substituent. The divalent aromatic group preferably contains at least 1 or more of a nitrogen atom, an oxygen atom, and a sulfur atom. When the number of aromatic groups contained in the divalent group Ar is 2 or more, 2 or more aromatic groups may be bonded to each other by a divalent linking group such as a single bond, -CO-O-, -O-.

G ¹ G (G) ² Each independently represents a divalent aromatic group or a divalent alicyclic hydrocarbon group. The hydrogen atom contained in the divalent aromatic group or the divalent alicyclic hydrocarbon group may be substituted with a halogen atom, a C1-4 alkyl group, a C1-4 fluoroalkyl group, a C1-4 alkoxy group, a cyano group or a nitro group, and the carbon atom constituting the divalent aromatic group or the divalent alicyclic hydrocarbon group may be replaced with an oxygen atom, a sulfur atom or a nitrogen atom.

L ¹ 、L ² 、B ¹ B (B) ² Each independently is a single bond or a divalent linking group.

k. l each independently represents an integer of 0 to 3, satisfying the relation 1.ltoreq.k+l. Here, B is, in the case of 2.ltoreq.k+l ¹ B (B) ² 、G ¹ G (G) ² The respective may be the same as each other or different from each other.

E ¹ E and E ² Each independently represents an alkanediyl group having 1 to 17 carbon atoms, wherein the hydrogen atoms contained in the alkanediyl group are optionally substituted by halogen atoms, and wherein-CH is contained in the alkanediyl group ₂ Can be selected from the group consisting of-O-, -S-, -a substitution of the COO-group, in a system having a plurality of-O-, -S-; in the case of a-COO-group, are not adjacent to each other.

P ¹ P ² Independently of one another, a polymerizable group or a hydrogen atom, at least 1 of which is a polymerizable group.]

G ¹ G (G) ² Each independently is preferably a 1, 4-phenylenediyl group which may be substituted with at least 1 substituent selected from the group consisting of a halogen atom and an alkyl group having 1 to 4 carbon atoms, or a 1, 4-cyclohexanediyl group which may be substituted with at least 1 substituent selected from the group consisting of a halogen atom and an alkyl group having 1 to 4 carbon atoms, more preferably a 1, 4-phenylenediyl group which is substituted with a methyl group, or an unsubstitutedSubstituted 1, 4-phenylenediyl or unsubstituted 1, 4-trans-cyclohexanediyl, with unsubstituted 1, 4-phenylenediyl or unsubstituted 1, 4-trans-cyclohexanediyl being particularly preferred.

In addition, a plurality of G's are preferably present ¹ G (G) ² At least 1 of them is a divalent alicyclic hydrocarbon group, and further, more preferably with L ¹ Or L ² Bonded G ¹ G (G) ² At least 1 of them is a divalent alicyclic hydrocarbon group.

L ¹ L and L ² Each independently is preferably a single bond, an alkylene group having 1 to 4 carbon atoms, -O-, -S-, -R ^a1 OR ^a2 -、-R ^a3 COOR ^a4 -、-R ^a5 OCOR ^a6 -、R ^a7 OC＝OOR ^a8 -、-N＝N-、-CR ^c ＝CR ^d -, or C.ident.C-. Here, R is ^a1 ～R ^a8 Each independently represents a single bond or an alkylene group having 1 to 4 carbon atoms, R ^c R is R ^d Represents an alkyl group having 1 to 4 carbon atoms or a hydrogen atom. L (L) ¹ L and L ² More preferably each independently is a single bond, -O ^Ra2-1 -、-CH ₂ -、-CH ₂ CH ₂ -、-COOR ^a4-1 -, or OCOR ^a6-1 -. Here, R is ^a2-1 、R ^a4-1 、R ^a6-1 Each independently represents a single bond, -CH ₂ -、-CH ₂ CH ₂ -any one of the following. L (L) ¹ L and L ² Each independently further preferably is a single bond, -O-, -CH ₂ CH ₂ -、-COO-、-COOCH ₂ CH ₂ -, or OCO-.

B ¹ B (B) ² Each independently is preferably a single bond, an alkylene group having 1 to 4 carbon atoms, -O-, -S-, -R ^a9 OR ^a10 -、-R ^a11 COOR ^a12 -、-R ^a13 OCOR ^a14 -, or R ^a15 OC＝OOR ^a16 -. Here, R is ^a9 ～R ^a16 Each independently represents a single bond or an alkylene group having 1 to 4 carbon atoms. B (B) ¹ B (B) ² More preferably each independently is a single bond, -OR ^a10-1 -、-CH ₂ -、-CH ₂ CH ₂ -、-COOR ^a12-1 -, or OCOR ^a14-1 -. Here, the，R ^a10-1 、R ^a12-1 、R ^a14-1 Each independently represents a single bond, -CH ₂ -、-CH ₂ CH ₂ -any one of the following. B (B) ¹ B (B) ² Each independently further preferably is a single bond, -O-, -CH ₂ CH ₂ -、-COO-、-COOCH ₂ CH ₂ -, -OCO-, or OCOCH ₂ CH ₂ -。

From the viewpoint of exhibiting inverse wavelength dispersibility, k and l are preferably in the range of 2.ltoreq.k+l.ltoreq.6, preferably k+l=4, more preferably k=2 and l=2. If k=2 and l=2, a symmetrical structure is formed, and thus preferable.

Preferably E ¹ E and E ² Each independently represents an alkanediyl group having 1 to 17 carbon atoms, more preferably an alkanediyl group having 4 to 12 carbon atoms.

As P ¹ Or P ² Examples of the polymerizable group include an epoxy group, a vinyl group, an ethyleneoxy group, a 1-chlorovinyl group, an isopropenyl group, a 4-vinylphenyl group, an acryloyloxy group, a methacryloyloxy group, an ethyleneoxy group, and an oxetanyl group. Among them, acryloyloxy, methacryloyloxy, ethyleneoxy, ethyleneoxide, and oxetanyl groups are preferable, and acryloyloxy is more preferable.

Ar preferably has at least one selected from the group consisting of an aromatic hydrocarbon ring which may have a substituent, an aromatic heterocyclic ring which may have a substituent, and an electron withdrawing group. Examples of the aromatic hydrocarbon ring include benzene ring, naphthalene ring, and anthracene ring, and benzene ring and naphthalene ring are preferable. Examples of the aromatic heterocycle include a furan ring, a benzofuran ring, a pyrrole ring, an indole ring, a thiophene ring, a benzothiophene ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a triazole ring, a triazine ring, a pyrroline ring, an imidazole ring, a pyrazole ring, a thiazole ring, a benzothiazole ring, a thienothiazole ring, an oxazole ring, a benzoxazole ring, and a phenanthroline ring. Among them, a thiazole ring, a benzothiazole ring, or a benzofuran ring is preferable, and a benzothiazolyl group is more preferable. In the case where a nitrogen atom is contained in Ar, it is preferable that the nitrogen atom has pi electrons.

In the formula (I), the total number N pi of pi electrons contained in the 2-valent aromatic group represented by Ar is preferably 8 or more, more preferably 10 or more, still more preferably 14 or more, and particularly preferably 16 or more. The content is preferably 30 or less, more preferably 26 or less, and even more preferably 24 or less.

Examples of the aromatic group represented by Ar include the following groups.

[ chemical 2]

[ in the formulae (Ar-1) to (Ar-23) ],

the reference numeral indicates a connecting portion,

Z ⁰ 、Z ¹ z is as follows ² Each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, a cyano group, a nitro group, an alkylsulfinyl group having 1 to 12 carbon atoms, an alkylsulfonyl group having 1 to 12 carbon atoms, a carboxyl group, a fluoroalkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkylthio group having 1 to 12 carbon atoms, an N-alkylamino group having 1 to 12 carbon atoms, an N, N-dialkylamino group having 2 to 12 carbon atoms, an N-alkylsulfonyl group having 1 to 12 carbon atoms or an N, N-dialkylsulfamoyl group having 2 to 12 carbon atoms.

Q ¹ Q and Q ² Each independently represents-CR ^2’ R ^3’ -、-S-、-NH-、-NR ^2’ -, -CO-or O-, R ² ' and R ^3’ Each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

J ¹ J ² Each independently represents a carbon atom, or a nitrogen atom.

Y ¹ 、Y ² Y and Y ³ Each independently represents an aromatic hydrocarbon group or an aromatic heterocyclic group which may be substituted.

W ¹ W and W ² Each independently represents a hydrogen atom, a cyano group, a methyl group, or a halogen atom.

m represents an integer of 0 to 6. ]

As Y ¹ 、Y ² Y and Y ³ Examples of the aromatic hydrocarbon group include phenyl, naphthyl, anthryl, phenanthryl, and,The aromatic hydrocarbon group having 6 to 20 carbon atoms such as biphenyl group is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. Examples of the aromatic heterocyclic group include a C4-20 aromatic heterocyclic group containing at least 1 hetero atom such as a nitrogen atom, an oxygen atom, a sulfur atom, etc., such as a furyl group, a pyrrolyl group, a thienyl group, a pyridyl group, a thiazolyl group, a benzothiazolyl group, etc., and a furyl group, a thienyl group, a pyridyl group, a thiazolyl group, a benzothiazolyl group are preferable.

Y ¹ 、Y ² Y and Y ³ Each independently may be a polycyclic aromatic hydrocarbon group or a polycyclic aromatic heterocyclic group which may be substituted. Polycyclic aromatic hydrocarbon group refers to a condensed polycyclic aromatic hydrocarbon group or a group derived from an aromatic ring set. Polycyclic aromatic heterocyclic groups refer to fused polycyclic aromatic heterocyclic groups or groups derived from an aromatic ring set.

Z ⁰ 、Z ¹ Z is as follows ² Each independently is preferably a hydrogen atom, a halogen atom, a C1-12 alkyl group, a cyano group, a nitro group, a C1-12 alkoxy group, Z ⁰ More preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a cyano group, Z ¹ Z is as follows ² More preferably a hydrogen atom, a fluorine atom, a chlorine atom, a methyl group, or a cyano group.

Q ¹ Q and Q ² preferably-NH-, -S-, -NR ^2’ -、-O-，R ^2’ Preferably a hydrogen atom. Wherein, particularly preferred are-S-; -O-, -NH-.

Among the compounds represented by the formulae (Ar-1) to (Ar-23), compounds represented by the formulae (Ar-6) and (Ar-7) are preferable from the viewpoint of the stability of the molecule.

In the compounds represented by the formulas (Ar-16) to (Ar-23), Y ¹ To which nitrogen atoms, Z, may be bound ⁰ Together forming an aromatic heterocyclic group. Examples of the aromatic heterocyclic group include the aromatic heterocyclic groups described above as aromatic heterocyclic groups that Ar may have, and examples thereof include pyrrole rings, imidazole rings, pyrroline rings, pyridine rings, pyrazine rings, pyrimidine rings, indole rings, quinoline rings, isoquinoline rings, purine rings, pyrrolidine rings, and the like. The aromatic heterocyclic group may have a substituent. In addition, Y ¹ To which nitrogen atoms may be boundZ is as follows ⁰ Together are the aforementioned polycyclic aromatic hydrocarbon group or polycyclic aromatic heterocyclic group which may be substituted. Examples thereof include a benzofuran ring, a benzothiazole ring, and a benzoxazole ring.

Among the polymerizable liquid crystal compounds, compounds having a maximum absorption wavelength of 300 to 400nm are preferable. The liquid crystal composition 2 is advantageous in terms of long-term stability, and can improve the alignment properties and uniformity of film thickness of the cured product layer of the liquid crystal composition 2 contained in the liquid crystal phase difference layer 1 and the liquid crystal phase difference layer 2. The maximum absorption wavelength of the polymerizable liquid crystal compound can be measured in a solvent using an ultraviolet-visible spectrophotometer. The solvent is a solvent capable of dissolving the polymerizable liquid crystal compound, and examples thereof include chloroform.

Examples of the discotic polymerizable liquid crystal compound include a compound containing a group represented by the formula (W) (hereinafter also referred to as "polymerizable liquid crystal compound (W)").

[ chemical 3]

[ in formula (W), R ⁴⁰ The following formulas (W-1) to (W-5) are shown.]

[ chemical 4]

[ in the formulae (W-1) to (W-5),

X ⁴⁰ z is as follows ⁴⁰ Each independently represents an alkanediyl group having 1 to 12 carbon atoms, wherein the hydrogen atoms contained in the alkanediyl group are optionally substituted by alkoxy groups having 1 to 5 carbon atoms, and wherein the hydrogen atoms contained in the alkoxy groups are optionally substituted by halogen atoms. In addition, the-CH constituting the alkanediyl group ₂ Can be replaced by-O-or-CO-.

m2 represents an integer. ]

Examples of the rod-shaped polymerizable liquid crystal compound include compounds represented by the formula (II), the formula (III), the formula (IV), the formula (V), the formula (VI) and the formula (VII).

P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-B16-E12-B17-P12

(II)

P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-F11(III)

P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-E12-B17-P12(IV)

P11-B11-E11-B12-A11-B13-A12-B14-A13-F11(V)

P11-B11-E11-B12-A11-B13-A12-B14-E12-B17-P12(VI)

P11-B11-E11-B12-A11-B13-A12-F11(VII)

[ in the formulae (II) to (VII),

a11 to A14 each independently represent a 2-valent alicyclic hydrocarbon group or a 2-valent aromatic hydrocarbon group. The hydrogen atoms contained in the alicyclic hydrocarbon group having 2 valence and the aromatic hydrocarbon group having 2 valence may be substituted with a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group or a nitro group, and the hydrogen atoms contained in the alkyl group having 1 to 6 carbon atoms and the alkoxy group having 1 to 6 carbon atoms may be substituted with a fluorine atom.

B11 and B17 each independently represent-O-, -S-, -CO-O-, -O-CO-O-, -CO-NR ¹⁶ -、-NR ¹⁶ -CO-, -CS-, or a single bond. R is R ¹⁶ Represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

B12 to B16 each independently represents-C.ident.C-, -CH=CH-, -CH ₂ -CH ₂ -、-O-、-S-、-C(＝O)-、-C(＝O)-O-、-O-C(＝O)-、-O-C(＝O)-O-、-CH＝N-、-N＝CH-、-N＝N-、-C(＝O)-NR ¹⁶ -、-NR ¹⁶ -C(＝O)-、-OCH ₂ -、-OCF ₂ -、-CH ₂ O-、-CF ₂ O-, -ch=ch-C (=o) -O-, -O-C (=o) -ch=ch-, or a single bond.

E11 and E12 each independently represent an alkanediyl group having 1 to 12 carbon atoms, wherein the hydrogen atoms in the alkanediyl group are optionally substituted by alkoxy groups having 1 to 5 carbon atoms, and wherein the hydrogen atoms in the alkoxy groups are optionally substituted by halogen atoms. In addition, the-CH constituting the alkanediyl group ₂ Can be replaced by-O-or-CO-.

F11 represents a hydrogen atomSon, alkyl with 1-13 carbon atoms, alkoxy with 1-13 carbon atoms, cyano, nitro, trifluoromethyl, dimethylamino, hydroxy, hydroxymethyl, formyl, sulfo (-SO) ₃ H) Carboxyl, alkoxycarbonyl having 1 to 10 carbon atoms or halogen atom, and-CH constituting the alkyl group and alkoxy group ₂ Can be replaced by-O-.

P11 and P12 each independently represent a polymerizable group. ]

The content of the polymerizable liquid crystal compound in the 2 nd liquid crystal composition is, for example, 70 to 99.5 parts by mass, preferably 80 to 99 parts by mass, based on 100 parts by mass of the solid content of the 2 nd liquid crystal composition. When the content of the polymerizable liquid crystal compound is within the above range, it is advantageous from the viewpoint of the orientation of the resulting cured product layer (liquid crystal cured film). In the present specification, the solid content of the 2 nd liquid crystal composition means all components obtained by removing volatile components such as an organic solvent from the 2 nd liquid crystal composition.

(substrate layer 1. Substrate layer 2)

As the 1 st substrate layer to which the 1 st liquid crystal composition is applied and the 2 nd substrate layer to which the 2 nd liquid crystal composition is applied, a glass substrate and a film substrate are exemplified, and a film substrate is preferable, and a long roll film is more preferable in terms of being able to continuously produce a liquid crystal polarizing plate, a 1 st liquid crystal retardation layer, and a 2 nd liquid crystal retardation layer. The 1 st liquid crystal composition and the 2 nd liquid crystal composition may be coated on the alignment films formed on the 1 st substrate layer and the 2 nd substrate layer, respectively.

Examples of the resin constituting the film base material include olefin resins such as polyethylene and polypropylene; a cyclic olefin resin having a ring system or norbornene structure; polyvinyl alcohol; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; a poly (meth) acrylic resin; cellulose ester resins such as triacetyl cellulose, diacetyl cellulose and cellulose acetate propionate; polyimide resin; a polycarbonate; polysulfone; polyether sulfone; polyether ketone; polyphenylene sulfide; polyphenylene ether, and the like.

As the film substrate, a commercially available cellulose ester resin substrate can be used. Examples of such cellulose ester resin substrates include "fujittack Film" (manufactured by fuji Film corporation); "KC8UX2M", "KC8UY" and "KC4UY" (manufactured by Konica Minolta Opto Co., ltd.) and the like.

As the cyclic olefin resin constituting the film base material, a commercially available cyclic olefin resin can be used. Examples of such a cycloolefin resin include "Topas" (registered trademark) (manufactured by Ticona corporation), "Arton" (registered trademark) (manufactured by JSR corporation), "ZEONOR" (registered trademark), and "ZEONEX" (registered trademark) (manufactured by ZEONEX corporation) and "APEL" (registered trademark) (manufactured by samsunk chemical corporation).

When the 1 st base material layer is used as the protective layer in its entirety or a part thereof, the 1 st base material layer preferably has the material and layer structure described above for the protective layer. In the case of using a part of the 1 st substrate layer as the protective layer, for example, the film substrate may be peeled off after forming a release layer on the surface of the film substrate and forming a liquid crystal polarizing plate on the film substrate.

In view of the quality of the degree of practical handling, the 1 st base material layer and the 2 nd base material layer are preferably thin, but if too thin, the strength tends to be low, and the workability tends to be poor. From this viewpoint, the thicknesses of the 1 st base material layer and the 2 nd base material layer are each independently usually 5 μm to 300 μm, preferably 10 μm to 200 μm, more preferably 10 to 50 μm. The optical laminate can be thinned by peeling the 1 st base layer and then transferring the liquid crystal polarizer (the cured product layer of the 1 st liquid crystal composition), and peeling the 2 nd base layer and then transferring the 1 st liquid crystal retardation layer and the 2 nd liquid crystal retardation layer.

(1 st orientation film, 2 nd orientation film)

The 1 st alignment film and the 2 nd alignment film have an alignment regulating force for aligning the liquid crystal of the polymerizable liquid crystal compound in a desired direction.

The 1 st alignment film and the 2 nd alignment film facilitate alignment of the liquid crystal of the polymerizable liquid crystal compound. The state of liquid crystal alignment such as horizontal alignment, vertical alignment, hybrid alignment, and tilt alignment varies depending on the properties of the 1 st and 2 nd alignment films and the polymerizable liquid crystal compound, and the combination thereof may be arbitrarily selected. For example, if the 1 st alignment film and/or the 2 nd alignment film is a material exhibiting horizontal alignment as an alignment regulating force, the polymerizable liquid crystal compound may be horizontally aligned or hybrid aligned, and if it is a material exhibiting vertical alignment, the polymerizable liquid crystal compound may be vertically aligned or tilted aligned. The expressions horizontal, vertical, etc. refer to the direction of the long axis of the polymerizable liquid crystal compound that is oriented when the planes of the liquid crystal polarizing plate and the 1 st and 2 nd liquid crystal retardation layers are taken as references. For example, the vertical alignment is a process of having the long axis of the polymerizable liquid crystal compound aligned in a direction perpendicular to the plane of the liquid crystal polarizing plate, the 1 st liquid crystal retardation layer, or the 2 nd liquid crystal retardation layer. The term "perpendicular" as used herein means 90++20° with respect to the plane of the liquid crystal polarizing plate, the 1 st liquid crystal retardation layer or the 2 nd liquid crystal retardation layer.

The alignment regulating force can be arbitrarily adjusted by the surface state and rubbing condition in the case where the alignment film is formed of an alignment polymer, and by the polarized light irradiation condition in the case where the alignment film is formed of a photo-alignment polymer. In addition, the liquid crystal orientation may be controlled by selecting physical properties such as surface tension and liquid crystallinity of the polymerizable liquid crystal compound.

When the 1 st alignment film and the 2 nd alignment film are formed between the film base material or the glass base material and the cured product layer of the 1 st liquid crystal composition or the 2 nd liquid crystal composition, the film base material or the glass base material is preferably insoluble in a solvent contained in the 1 st liquid crystal composition or the 2 nd liquid crystal composition, and the film base material or the glass base material is preferably heat-resistant in a heat treatment for removing the solvent and aligning the polymerizable liquid crystal compound. As the 1 st and 2 nd alignment films, an alignment film including an alignment polymer, a photo-alignment film and a groove (groove) alignment film, a stretched film stretched in the alignment direction, and the like can be cited independently, and in the case of being applied to a long roll film, a photo-alignment film is preferable in terms of being able to easily control the alignment direction.

The thickness of the 1 st orientation film and the 2 nd orientation film is usually in the range of 10nm to 5000nm, preferably in the range of 10nm to 1000nm, more preferably in the range of 30 to 300nm, independently of each other.

Examples of the alignment polymer used for the rubbing alignment film include polyamide having an amide bond in the molecule, gelatin, polyimide having an imide bond in the molecule, and polyamic acid, polyvinyl alcohol, alkyl-modified polyvinyl alcohol, polyacrylamide, polyoxazole, polyethylenimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid, and polyacrylate, which are hydrolysates thereof. Among them, polyvinyl alcohol is preferable. These alignment polymers may be used alone or in combination of 2 or more.

As a method of rubbing, there is a method of bringing a film of an alignment polymer formed on a film substrate or a glass substrate surface by applying an alignment polymer composition to the substrate and annealing, into contact with a rubbing roll around which a rubbing cloth is wound and which rotates.

The photo-alignment film comprises a polymer, oligomer or monomer having a photoreactive group. The photo-alignment film can obtain an alignment regulating force by irradiating polarized light. By selecting the polarization direction of the irradiated polarized light, the direction of the orientation restriction force can be arbitrarily controlled, and from this point of view, a photo-alignment film is more preferable.

The photoreactive group is a group that generates liquid crystal aligning ability by irradiation with light. Specifically, the group is a group that generates a photoreaction that causes the liquid crystal aligning ability, such as an alignment induction or isomerization reaction, dimerization reaction, photocrosslinking reaction, or photodecomposition reaction of a molecule generated by irradiation with light. Among the photoreactive groups, those that undergo dimerization or photocrosslinking are preferred in view of their excellent orientation. As the photoreactive group capable of undergoing the reaction described above, a group having an unsaturated bond, particularly a double bond, is preferable, and a group having at least one selected from a carbon-carbon double bond (c=c bond), a carbon-nitrogen double bond (c=n bond), a nitrogen-nitrogen double bond (n=n bond), and a carbon-oxygen double bond (c=o bond) is more preferable.

Examples of the photoreactive group having a c=c bond include a vinyl group, a polyalkenyl group, a stilbene oxazolyl group, a stilbene oxazolium group, a chalcone group, and a cinnamoyl group. From the viewpoint of easy control of reactivity and expression of orientation restriction force at the time of photo-orientation, a chalcone group and a cinnamoyl group are preferable. Examples of the photoreactive group having a c=n bond include groups having a structure such as an aromatic schiff base and an aromatic hydrazone. Examples of the photoreactive group having an n=n bond include groups having an azobenzene oxide as a basic structure, such as an azobenzene group, an azonaphthalene group, an aromatic heterocyclic azo group, a disazo group, and a formazan group. Examples of the photoreactive group having a c=o bond include a benzophenone group, a coumarin group, an anthraquinone group, and a maleimide group. These groups may have substituents such as alkyl, alkoxy, aryl, allyloxy, cyano, alkoxycarbonyl, hydroxyl, sulfonic acid, and haloalkyl.

In the case of irradiating polarized light, polarized light may be directly irradiated from the film surface, or polarized light may be irradiated from the film substrate or glass substrate side, or polarized light may be transmitted. In addition, it is particularly preferable that the polarized light is substantially parallel light. The wavelength of the irradiated polarized light is preferably a wavelength in a wavelength region where the photoreactive group of the polymer or monomer having the photoreactive group can absorb light energy. Specifically, UV (ultraviolet light) having a wavelength in the range of 250 to 400nm is particularly preferable.

(1 st bonding layer, 2 nd bonding layer, 3 rd bonding layer, adhesive layer)

The 1 st bonding layer and the 2 nd bonding layer are cured layers of the active energy ray-curable composition, and are bonding layers called "adhesive layers". The 3 rd lamination layer may be an adhesive layer, but is preferably a lamination layer having a glass transition temperature Tg of 25 ℃ or less. The adhesive layer may be formed using an adhesive composition, and the adhesive layer having a Tg of 25 ℃ or less may be formed using an adhesive composition, for example. The Tg of the conformable layer can be measured using a Differential Scanning Calorimeter (DSC).

Examples of the adhesive composition include an aqueous adhesive composition and an active energy ray-curable composition cured by irradiation with active energy rays such as heat, ultraviolet rays, visible light, electron beams, and X rays. Examples of the aqueous adhesive composition include a composition in which a polyvinyl alcohol resin or a urethane resin is dissolved in water as a main component and a composition in which a polyvinyl alcohol resin or a urethane resin is dispersed in water as a main component. The aqueous adhesive composition may further contain a curable component such as a polyaldehyde, a melamine compound, a zirconium dioxide compound, a zinc compound, a glyoxal compound, a water-soluble epoxy resin, and a crosslinking agent.

The adhesive composition is preferably an active energy ray-curable composition that contains a curable (polymerizable) compound as a main component and is cured by irradiation with active energy rays. Examples of the active energy ray-curable composition include a cation-polymerizable adhesive composition containing a cation-polymerizable compound as a curable compound, a radical-polymerizable adhesive composition containing a radical-polymerizable compound as a curable compound, and a mixed adhesive composition containing both a cation-polymerizable compound and a radical-polymerizable compound as curable compounds.

The cationically polymerizable compound is a compound or oligomer which is cured by cationic polymerization reaction by irradiation with active energy rays such as ultraviolet rays, visible light, electron beams, X-rays, and the like, and is specifically exemplified by epoxy compounds, oxetane compounds, vinyl compounds, and the like.

Examples of the epoxy compound include alicyclic epoxy compounds (compounds having 1 or more epoxy groups bonded to an alicyclic ring in the molecule) such as 3, 4-epoxycyclohexylmethyl 3, 4-epoxycyclohexane carboxylate; aromatic epoxy compounds (compounds having an aromatic ring and an epoxy group in the molecule) such as diglycidyl ether of bisphenol a; aliphatic epoxy compounds such as 2-ethylhexyl glycidyl ether and 1, 4-butanediol diglycidyl ether (compounds having at least 1 oxirane ring bonded to an aliphatic carbon atom in the molecule), and the like.

Examples of oxetane compounds include compounds having 1 or more oxetane rings in the molecule, such as 3-ethyl-3- { [ (3-ethyloxetan-3-yl) methoxy ] methyl } oxetane.

The cationically polymerizable adhesive composition preferably contains a cationic polymerization initiator. The cationic polymerization initiator may be a thermal cationic polymerization initiator or a photo cationic polymerization initiator. Examples of the cationic polymerization initiator include aromatic diazonium salts such as phenyldiazonium hexafluoroantimonate; aromatic iodonium salts such as diphenyliodonium tetrakis (pentafluorophenyl) borate; aromatic sulfonium salts such as triphenylsulfonium hexafluorophosphate; iron-arene complexes such as xylene-cyclopentadienyl iron (II) hexafluoroantimonate. The content of the cationic polymerization initiator is usually 0.1 to 10 parts by mass relative to 100 parts by mass of the cationically polymerizable compound. More than 2 cationic polymerization initiators may be included.

Examples of the cationically polymerizable adhesive composition include the cationically polymerizable compositions described in JP-A2016-126345 and JP-A2021-113969.

The radical polymerizable compound is a compound or oligomer which undergoes radical polymerization and curing by irradiation with active energy rays such as ultraviolet rays, visible light, electron beams, X-rays, and the like, and specifically, a compound having an ethylenically unsaturated bond is exemplified. Examples of the compound having an ethylenically unsaturated bond include a (meth) acrylic compound having 1 or more (meth) acryloyl groups in the molecule, a vinyl compound having 1 or more vinyl groups in the molecule, and the like.

Examples of the (meth) acrylic compound include (meth) acryl-containing compounds such as (meth) acrylic oligomers having at least 2 (meth) acryl groups in the molecule, which are obtained by reacting 2 or more functional group-containing compounds with a (meth) acrylic monomer having at least 1 (meth) acryloyloxy group in the molecule.

The radical polymerizable adhesive composition preferably contains a radical polymerization initiator. The radical polymerization initiator may be a thermal radical polymerization initiator or a photo radical polymerization initiator. Examples of the radical polymerization initiator include acetophenone-based initiators such as acetophenone and 3-methylacetophenone; benzophenone-based initiators such as benzophenone, 4-chlorobenzophenone and 4,4' -diaminobenzophenone; benzoin ether initiators such as benzoin propyl ether and benzoin diethyl ether; thioxanthone-based initiators such as 4-isopropylthioxanthone; xanthone, fluorenone, and the like. The content of the radical polymerization initiator is usually 0.1 to 10 parts by mass based on 100 parts by mass of the radical polymerizable compound. It may contain 2 or more radical polymerization initiators.

Examples of the radical polymerizable adhesive composition include radical polymerizable compositions described in Japanese patent application laid-open No. 2016-126345, japanese patent application laid-open No. 2016-153474, and International publication No. 2017/183335.

The active energy ray-curable adhesive composition may contain, if necessary, an ion scavenger, an antioxidant, a chain transfer agent, a tackifier, a thermoplastic resin, a filler, a flow regulator, a plasticizer, a defoaming agent, an antistatic agent, a leveling agent, a solvent, and other additives.

The adhesive composition is applied to the bonding surface of at least one of the 2 layers bonded by the 1 st bonding layer or the 2 nd bonding layer, the 2 layers are laminated via the application layer of the adhesive composition, and the bonding is performed by pressing the adhesive composition from above and below using a bonding roller or the like, and then the application layer is dried, and the application layer is cured by irradiation with active energy rays, or is cured by heating.

At least one of the bonding surfaces of the 2 layers may be subjected to an easy-to-adhere treatment such as saponification treatment, corona treatment, plasma treatment, primer treatment, anchor coating treatment, and the like before the adhesive composition is applied to the coating layer.

In forming the coating layer of the adhesive composition, various coating methods such as a die coater, a comma type blade coater, a gravure coater, a wire bar coater, and a blade coater can be used.

The irradiation intensity of the active energy ray upon irradiation is determined according to each composition of the active energy ray-curable adhesive composition, and is not particularly limited, but is preferably 10 mW/cm ² Above and 1000mW/cm ² The following is given. The irradiation intensity is preferably an intensity in a wavelength region effective for activation of the photo-cationic polymerization initiator or the photo-radical polymerization initiator.

Preferably, the irradiation is performed 1 or more times with such light irradiation intensity and the cumulative light amount thereof is set to 10mJ/cm ² The above is more preferably set to 100mJ/cm ² Above and 1000mJ/cm ² The following is given.

The light source used for polymerization curing of the active energy ray-curable adhesive composition is not particularly limited, and examples thereof include a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a xenon lamp, a halogen lamp, a chemical lamp, a black light lamp, a microwave-excited mercury lamp, and a metal halide lamp.

The thickness of the adhesive layer formed of the aqueous adhesive composition may be, for example, 5 μm or less, preferably 1 μm or less, more preferably 0.5 μm or less, and may be 0.01 μm or more, preferably 0.05 μm or more.

The thickness of the cured product layer (adhesive layer) formed from the active energy ray-curable adhesive composition may be, for example, 10 μm or less, preferably 5 μm or less, more preferably 3 μm or less, and may be 0.1 μm or more, preferably 0.5 μm or more, more preferably 1 μm or more.

The pressure-sensitive adhesive composition is not particularly limited, and a pressure-sensitive adhesive composition having excellent optical transparency, which is known in the related art, may be used, for example, a pressure-sensitive adhesive composition having a base polymer such as a (meth) acrylic resin, a urethane resin, a silicone resin, or a polyvinyl ether resin. The adhesive composition may be an active energy ray-curable adhesive composition, a thermosetting adhesive composition, or the like. Among them, an adhesive composition containing an acrylic resin as a base polymer, which is excellent in transparency, adhesion, re-peelability, weather resistance, heat resistance, and the like, is suitable.

The adhesive composition may further comprise a crosslinking agent, a silane compound, an antistatic agent, and the like.

The (meth) acrylic resin contained in the adhesive composition is preferably a polymer (hereinafter also referred to as "(meth) acrylate polymer") containing a structural unit derived from an alkyl (meth) acrylate represented by the following formula (VIII) (hereinafter also referred to as "structural unit (VIII)") as a main component (for example, 50 parts by mass or more per 100 parts by mass of the structural unit of the (meth) acrylic resin).

[ chemical 5]

In the formula (VIII),

R ¹⁰ Represents a hydrogen atom or a methyl group,

R ²⁰ an alkyl group having 1 to 20 carbon atoms is represented, and the alkyl group may have any of a linear, branched or cyclic structure, and a hydrogen atom of the alkyl group may be substituted with an alkoxy group having 1 to 10 carbon atoms.]

Examples of the (meth) acrylic acid ester represented by the formula (VIII) include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, isohexyl (meth) acrylate, n-heptyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, n-dodecyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, stearyl (meth) acrylate, and t-butyl (meth) acrylate. Specific examples of the alkyl acrylate containing an alkoxy group include 2-methoxyethyl (meth) acrylate, ethoxymethyl (meth) acrylate, and the like. Among them, n-butyl (meth) acrylate or 2-ethylhexyl (meth) acrylate is preferably contained, and n-butyl (meth) acrylate is particularly preferably contained.

The (meth) acrylate polymer may contain structural units derived from other monomers in addition to the structural unit (VIII). The number of structural units derived from other monomers may be 1 or 2 or more. Examples of the other monomer that can be contained in the (meth) acrylate polymer include a monomer having a polar functional group, a monomer having an aromatic group, and an acrylamide monomer.

Examples of the monomer having a polar functional group include (meth) acrylic esters having a polar functional group. Examples of the polar functional group include a hydroxyl group; a carboxyl group; substituted amino group or unsubstituted amino group substituted with alkyl group having 1 to 6 carbon atoms; heterocyclic groups such as epoxy groups, and the like.

The content of the structural unit derived from the monomer having a polar functional group in the (meth) acrylate polymer is preferably 10 parts by mass or less, more preferably 0.5 parts by mass or more and 10 parts by mass or less, and still more preferably 1 part by mass or more and 5 parts by mass or less, relative to 100 parts by mass of the total structural units of the (meth) acrylate polymer.

Examples of the monomer having an aromatic group include (meth) acrylic esters each having 1 (meth) acryloyl group and 1 or more aromatic rings (for example, benzene ring, naphthalene ring, etc.) in the molecule and having a phenyl group, phenoxyethyl group, or benzyl group.

The content of the structural unit derived from the monomer having an aromatic group in the (meth) acrylate polymer is preferably 4 parts by mass or more and 20 parts by mass or less, more preferably 4 parts by mass or more and 15 parts by mass or less, relative to 100 parts by mass of the total structural units of the (meth) acrylate polymer.

Examples of the acrylamide monomer include N- (methoxymethyl) acrylamide, N- (ethoxymethyl) acrylamide, N- (propoxymethyl) acrylamide, N- (butoxymethyl) acrylamide, and N- (2-methylpropoxymethyl) acrylamide.

The structural unit derived from a monomer other than the structural unit (VIII) may include a structural unit derived from a styrene monomer, a structural unit derived from a vinyl monomer, a structural unit derived from a monomer having a plurality of (meth) acryloyl groups in the molecule, and the like.

The weight average molecular weight (hereinafter also simply referred to as "Mw") of the (meth) acrylic resin is preferably 50 to 250 ten thousand. When the weight average molecular weight is 50 ten thousand or more, the durability of the adhesive layer in a high-temperature and high-humidity environment can be improved. When the weight average molecular weight is 250 ten thousand or less, the workability in applying a coating liquid containing the adhesive composition becomes good. The molecular weight distribution (Mw/Mn), expressed as a ratio of the weight average molecular weight (Mw) to the number average molecular weight (hereinafter also simply referred to as "Mn"), is usually 2 to 10. In the present specification, the term "weight average molecular weight" and "number average molecular weight" are polystyrene equivalent values measured by Gel Permeation Chromatography (GPC).

When the (meth) acrylic resin is dissolved in ethyl acetate to prepare a solution having a concentration of 20% by mass, the viscosity at 25℃is preferably 20 Pa.s or less, more preferably 0.1 to 15 Pa.s. When the viscosity of the (meth) acrylic resin at 25 ℃ is within the above range, the durability and reworkability of the optical laminate including the adhesive layer formed from the resin can be improved. The viscosity can be measured by a brookfield viscometer.

The glass transition temperature (Tg) of the (meth) acrylic resin is, for example, -60 to 20 ℃, preferably-50 to 15 ℃, more preferably-45 to 10 ℃, still more preferably-40 to 0 ℃. The glass transition temperature may be measured by a Differential Scanning Calorimeter (DSC).

The (meth) acrylic resin may contain 2 or more (meth) acrylate polymers. Examples of such a (meth) acrylate polymer include (meth) acrylate polymers having a lower molecular weight, which mainly contains a structural unit (VIII) derived from the (meth) acrylate and has a weight average molecular weight in the range of 5 to 30 tens of thousands.

The (meth) acrylic resin can be generally produced by a known polymerization method such as a solution polymerization method, a bulk polymerization method, a suspension polymerization method, or an emulsion polymerization method. In the production of (meth) acrylic resins, polymerization is usually carried out in the presence of a polymerization initiator. The amount of the polymerization initiator is usually 0.001 to 5 parts by mass based on 100 parts by mass of the total of all monomers constituting the (meth) acrylic resin.

The adhesive composition preferably comprises a cross-linking agent. Examples of the crosslinking agent include conventional crosslinking agents (for example, isocyanate compounds, epoxy compounds, aziridine compounds, metal chelate compounds, peroxides, and the like), and isocyanate compounds are preferable from the viewpoints of usable time of the adhesive composition, crosslinking speed, durability of the polarizing plate, and the like. The proportion of the crosslinking agent is, for example, 0.01 to 10 parts by mass, preferably 0.05 to 5 parts by mass, relative to 100 parts by mass of the (meth) acrylic resin.

The adhesive composition may further contain a silane compound. The content of the silane compound in the adhesive composition is usually 0.01 to 10 parts by mass relative to 100 parts by mass of the (meth) acrylic resin.

The adhesive composition may further comprise an antistatic agent. The antistatic agent may be a known antistatic agent, and is preferably an ionic antistatic agent. From the viewpoint of excellent stability of antistatic performance of the adhesive composition with time, an ionic antistatic agent that is solid at room temperature is preferable. The content of the antistatic agent is preferably 0.01 to 20 parts by mass, more preferably 1 to 7 parts by mass, relative to 100 parts by mass of the (meth) acrylic resin.

The thickness of the pressure-sensitive adhesive layer is usually 0.1 to 30. Mu.m, preferably 3 to 30. Mu.m, more preferably 5 to 25. Mu.m.

The storage modulus of the adhesive layer at a temperature of 25℃is preferably 1.0X10 ⁴ Pa～1.0×10 ⁶ Pa, more preferably 1.0X10 ⁴ Pa～1.0×10 ⁵ Pa. The storage modulus can be obtained using a dynamic viscoelasticity measurement.

The creep amount ΔCr of the pressure-sensitive adhesive layer at a temperature of 70 ℃ may be, for example, 65 μm or less, 50 μm or less, 45 μm or less, 40 μm or less, 35 μm or less, 30 μm or less, 25 μm or less, 20 μm or less, and further 15 μm or less. The lower limit of the creep amount DeltaCr is, for example, 0.5. Mu.m. If the creep amount is in such a range, the lack of adhesive, the adhesive stain, and the cutting failure when cutting the optical laminate can be suppressed as in the case of the storage modulus. The creep value can be measured, for example, by the following steps: to the following pair ofThe joint surface of 20mm in the vertical direction and 20mm in the horizontal direction was adhered to the adhesive layer of the stainless steel test plate, and a load of 500gf was applied vertically downward in a state where the test plate was fixed. The creep amount (displacement amount) of the adhesive layer with respect to the test plate at each time after 100 seconds and 3600 seconds from the load application was measured and was referred to as Cr ₁₀₀ Cr ₃₆₀₀ . Based on the measured Cr ₁₀₀ Cr ₃₆₀₀ The formula Δcr=cr may be used ₃₆₀₀ -Cr ₁₀₀ The creep amount Δcr was obtained.

(spacer)

The spacer is provided so as to be capable of peeling off the 3 rd lamination layer for laminating the optical laminate to the display element, and is provided so as to cover and protect the surface of the 3 rd lamination layer. When the spacer is peeled from the 3 rd lamination layer of the optical laminate with the spacer, the spacer can be peeled while maintaining the shape of the 3 rd lamination layer. The spacer is preferably a spacer having a base film and a release treatment layer. The substrate film may be a film formed of a resin, and examples of the resin include film substrates used in the 1 st substrate layer and the 2 nd substrate layer. The release treatment layer may be any known release treatment layer, and examples thereof include a layer formed by applying a release agent such as a fluorine compound or a silicone compound to a base film.

Examples

Hereinafter, the present invention will be described in further detail by way of examples, but the present invention is not limited to these examples. In the examples and comparative examples, "%" and "parts" are "% by mass" and "parts by mass" unless otherwise specified.

[ measurement of thickness ]

In the measurement of the thickness of each layer, unless otherwise specified, a laser microscope (LEXT, manufactured by Olympus Co., ltd.) or a digital micrometer "MH-15M" manufactured by Nikon Co., ltd.) was used.

[ production of polarizing plate (1) with substrate layer ]

(preparation of liquid Crystal composition 1)

The following components were mixed and stirred at a temperature of 80℃for 1 hour, thereby obtaining a 1 st liquid crystal composition. The polymerizable liquid crystal compounds (X1) and (X2) have the following structures. The dichroic dyes (DP 1) to (DP 3) are azo dyes described in examples of japanese patent application laid-open No. 2013-101328, and have the following structures.

Polymerizable liquid crystal compound (X1): 75 parts of

Polymerizable liquid crystal compound (X2): 25 parts of

Dichroic dye (DP 1): 2.5 parts of

Dichroic dye (DP 2): 2.5 parts of

Dichroic dye (DP 3): 2.5 parts of

6 parts of a polymerization initiator [ 2-dimethylamino-2-benzyl-1- (4-morpholinophenyl) butan-1-one (Irga cure (registered trademark) 369, manufactured by BASF JAPAN Co., ltd.)

Leveling agent [ polyacrylate Compound (BYK-361N; BYK-Chemie Co.) ]:1.2 parts of

Solvent [ o-xylene ]:250 parts

Polymerizable liquid crystal compound (X1):

[ chemical 6]

Polymerizable liquid crystal compound (X2):

[ chemical 7]

Dichroic dye (DP 1):

[ chemical 8]

Dichroic dye (DP 2):

[ chemical 9]

Dichroic dye (DP 3):

[ chemical 10]

(preparation of composition (1) for Forming photo-alignment film)

The following components described in JP-A2013-033249 were mixed, and the resultant mixture was stirred at 80℃for 1 hour, thereby obtaining a composition (1) for forming a photo-alignment film.

Light-oriented polymers of the structure shown below: 2 parts of

[ chemical 11]

Solvent [ o-xylene ]:98 parts of

(preparation of aqueous solution of Water-soluble Polymer)

According to the following synthesis scheme, a water-soluble polymer comprising the following structural units was obtained.

[ chemical 12]

20g of polyvinyl alcohol having a molecular weight of 1000 (manufactured by Wako pure chemical industries, ltd.) and 0.55mg of N, N-dimethyl-4-aminopyridine and 4.6g of triethylamine as nucleophile were dissolved in 400g of dimethyl sulfoxide, and the temperature was raised to 60℃while stirring. Thereafter, a solution of 10.5g of methacrylic anhydride dissolved in 50g of dimethyl sulfoxide was added dropwise over 1 hour, and the mixture was heated and stirred at 60℃for 14 hours, whereby the mixture was reacted. After the obtained reaction solution was cooled to room temperature, 481g of methanol was added to the reaction solution and stirred until completely mixed, whereby the ratio (mass) of the reaction solution to methanol was adjusted to 1:1. 1500mL of acetone was slowly added to the solution, whereby the water-soluble polymer was crystallized by a crystallization method. The resulting solution containing white crystals was filtered, sufficiently washed with acetone, and then vacuum-dried, whereby 20.2g of a water-soluble polymer was obtained. The obtained water-soluble polymer was dissolved in water to prepare a 3 mass% water-soluble polymer aqueous solution.

(preparation of composition for Forming HC layer)

The following components were mixed and stirred at a temperature of 50℃for 4 hours to obtain a composition for forming a Hard Coat (HC) layer.

Acrylate monomer of the structure shown below: 70 parts of

[ chemical 13]

Urethane acrylate resin [ EBECRYL4858 (Daicel Allnex Co., ltd.) ]:30 parts of

Polymerization initiator [ Omnirad907 (made by IGM Resins B.V.) ]:3 parts of

Solvent [ methyl ethyl ketone ]:10 parts of

(production of polarizing plate (1) with base layer)

The HC layer-forming composition obtained above was continuously applied to a release treated surface of a polyethylene terephthalate (PET) film (FF-50 manufactured by UNI CHIKA, inc., single-sided release treated PET film (thickness of support substrate: 50 μm)) in a roll form having a film width of 800mm, and dried at 100℃for 2 minutes to form an HC layer (protective layer) having a thickness of 2.00. Mu.m. Thus, a film in which an HC layer was laminated on the release treated surface of the single-sided release treated PET film was obtained as the 1 st base layer (1).

After plasma treatment was performed on the HC layer of the 1 st base material layer (1), the composition (1) for forming a photo-alignment film prepared above was applied using a slit coater, and a coating layer was formed in a range of 600mm in width at the central portion of the single-sided release-treated PET film. Next, the solvent was removed by carrying for 2 minutes in a ventilation drying oven set at a temperature of 100 ℃ to dry the coating layer on the HC layer. Thereafter, the dried material is put on The coating layer is coated to 20mJ/cm ² A photo-alignment film (1) is formed on the HC layer by applying an alignment regulating force by irradiating polarized UV light in a direction of 90 DEG with respect to the longitudinal direction of the single-sided release-treated PET film so as to have an intensity (313 nm reference). The thickness of the photo-alignment film (1) was about 50nm.

The 1 st liquid crystal composition prepared above was coated on the photo-alignment film (1) formed on the 1 st substrate layer (1) using a slit coater, and a coating layer was formed in the range of 600mm in width of the central portion of the 1 st substrate layer (1). Next, the solvent was removed by carrying for 2 minutes in a ventilation drying oven set at a temperature of 110 ℃, and the coating layer on the 1 st base material layer (1) was dried. Thereafter, a high-pressure mercury lamp was used at 1000mJ/cm ² Ultraviolet light is irradiated (based on 365 nm), and the polymerizable liquid crystal compound contained in the dried coating layer is cured to form a cured product layer of the 1 st liquid crystal composition, thereby obtaining a liquid crystal polarizer (1) with a substrate layer, wherein the photo-alignment film (1) and the cured product layer (collectively, liquid crystal polarizer) are sequentially formed on the 1 st substrate layer (1). The liquid crystal polarizer (1) with a base material layer has an absorption axis in a direction of 90 DEG relative to the longitudinal direction. The thickness of the cured layer was 3. Mu.m.

Then, after plasma treatment was performed on the liquid crystal polarizer side of the liquid crystal polarizer (1) with the base material layer, the water-soluble polymer aqueous solution prepared above was continuously coated using a slit coater, and dried at 100 ℃ for 2 minutes to form an overcoat layer (2 nd protective layer) having a thickness of 2 μm. Thus, a long polarizing plate (1) with a base material layer comprising, in order, the 1 st base material layer (1) (single-sided release treatment PET film/HC layer)/liquid crystal polarizing plate (photo-alignment film (1)/cured product layer)/overcoat layer was obtained.

The resulting polarizing plate (1) with a base material layer was cut into squares of 40mm by 40mm in size. An acrylic pressure-sensitive adhesive (trade name "P-3132" manufactured by LINTEC Co., ltd.) having a thickness of 25 μm was applied to an alkali-free glass plate (trade name "Eagle-XG" manufactured by Corning Co., ltd.) on the outer coating side, and then the single-sided release-treated PET film was peeled off to obtain a test piece.

The transmittance (T1) of the resultant test body in the transmission axis direction and the transmittance (T2) of the test body in the absorption axis direction were measured by a two-beam method using a device in which a holder having a polarizing plate was provided in a spectrophotometer (UV-3150 manufactured by Shimadzu corporation) in a wavelength range of 380 to 680nm in 2nm steps. The monomer transmittance and polarization degree at each wavelength were calculated using the following formulas (formula 1) and (formula 2), and then the visibility correction was performed using the 2-degree field of view (C light source) of JIS Z8701, to calculate the visibility correction monomer transmittance (Ty) and the visibility correction polarization degree (Py).

Monomer transmittance [% ] = (t1+t2)/2 (formula 1)

Degree of polarization [% ] = [ (T1-T2)/(t1+t2) ] x 100 (2)

As a result, the visibility-corrected monomer transmittance (Ty) of the test piece was 42%, and the visibility-corrected polarization degree (Py) was 97%, and a value useful as a polarizing plate was confirmed. After the test piece was heated at 100℃for 120 hours, the visibility-corrected monomer transmittance (Ty) and the visibility-corrected polarization degree (Py) were calculated by the above-described procedure, and as a result, the transmittance (Ty) of the heated test piece was 42%, the visibility-corrected polarization degree (Py) was 97%, and no decrease in optical performance was observed.

[ production of polarizing plate (2) with substrate layer ]

Except that the thickness of the HC layer (protective layer) formed on the single-sided release-treated PET film was changed to 3.95 μm, a polarizing plate (2) with a base layer was produced by a production step of the polarizing plate (1) with a base layer.

[ production of polarizing plate (3) with substrate layer ]

Except that the thickness of the HC layer (protective layer) formed on the single-sided release-treated PET film was changed to 4.95 μm, a polarizing plate (3) with a base layer was produced by a production step of the polarizing plate (1) with a base layer.

[ production of the 1 st liquid Crystal retardation layer (1) ]

(preparation of composition (1) for Forming an alignment film)

Water was added to a commercially available polyvinyl alcohol (polyvinyl alcohol 1000 completely saponified, manufactured by Wako pure chemical industries, ltd.) and heated at 100℃for 1 hour to obtain a composition (1) for forming an alignment film.

(preparation of liquid Crystal composition (1))

The polymerizable liquid crystal compound (X3) and the polymerizable liquid crystal compound (X4) shown below were mixed, and a leveling agent, a photopolymerization initiator, and an ionic compound shown below were added thereto, followed by addition of a solvent shown below, to obtain a mixture. The mixture was stirred at a temperature of 80℃for 1 hour, thereby preparing a 2 nd liquid crystal composition (1). The polymerizable liquid crystal compounds (X3) and (X4) are prepared according to the method described in JP-A2010-244038, and have the following structures. The ionic compound has the structure shown below.

Polymerizable liquid crystal compound (X3): 80 parts of

Polymerizable liquid crystal compound (X4): 20 parts of

Leveling agent [ MEGAFAC F-556 (DIC Co.) ]:0.1 part

Photopolymerization initiator [ Omnirad907 (made by IGM Resin B.V.): 2.5 parts of

Ionic compound: 0.1 part

Solvent [ cyclopentanone ]:650 parts of

Polymerizable liquid crystal compound (X3):

[ chemical 14]

[ 15]

Ionic compound:

[ 16]

(production of 1 st liquid Crystal phase-difference layer (1) with base layer)

Is cut into rectangular shapesA cycloolefin polymer (COP) film (ZEON Co., ltd., ZF 14) was subjected to corona treatment using a corona treatment device (AGF-B10; manufactured by Chun electric Co., ltd.) and then coated with the composition (1) for forming an alignment film, and then dried by heating to form an alignment film having a thickness of 100 nm. The surface of the obtained alignment film was subjected to rubbing treatment at an angle of 75 ° with respect to the longitudinal direction of the COP film, and the 2 nd liquid crystal composition (1) was applied on the surface by a bar coater. The resulting coating film was dried at a temperature of 120℃for 2 minutes, and then irradiated with a high-pressure mercury lamp (UNICURE VB-15201BY-A, manufactured BY USHIO Motor Co., ltd.) at a temperature of 80℃under a nitrogen atmosphere to give a film having an exposure of 1000mJ/cm ² Ultraviolet light (365 nm basis), thereby forming a cured product layer (1-1) of the polymerizable liquid crystal compound obtained by curing the polymerizable liquid crystal compound in a state in which the optical axis of the polymerizable liquid crystal compound is oriented in the horizontal direction with respect to the COP film surface. Thus, a 1 st liquid crystal retardation layer (1) with a base material layer comprising a 2 nd base material layer (COP film)/a 1 st liquid crystal retardation layer (1) (alignment film/cured product layer (1-1)) was obtained.

The thickness of the cured product layer (1-1) was measured by a laser microscope, and found to be 2. Mu.m. The in-plane retardation value of the 1 st liquid crystal retardation layer (1) was measured by using KOBRA-WR manufactured by prince measuring instruments Co. As a result, the in-plane phase difference value at the wavelength of 550nm was Re (550) =270 nm. Since the phase difference value at 550nm of the COP film is approximately 0, the COP film has no influence on the optical characteristics of the 1 st liquid crystal retardation layer (1). The orientation angle was-15 ° with respect to the long side direction of the COP film.

[ production of the 2 nd liquid Crystal phase-difference layer (1) ]

(preparation of liquid Crystal composition (2))

The 2 nd liquid crystal composition (2) was prepared by mixing the polymerizable liquid crystal compound (X5) shown below, a leveling agent and a photopolymerization initiator, followed by mixing the solvent shown below, and stirring at a temperature of 80 ℃ for 1 hour. The polymerizable liquid crystal compound (X5) has the following structure.

Polymerizable liquid crystal compound (X5) [ Paliocolor LC242 (manufactured by BASF JAPAN Co.) ]:100 parts of

Leveling agent [ BYK-361N (BYK-Chemie Co.) ]:0.1 part

Solvent [ propylene glycol 1-monomethyl ether 2-acetate (PGME) ]:400 parts of

Polymerizable liquid crystal compound (X5):

[ chemical 17]

(production of the 2 nd liquid Crystal phase-difference layer (1) with base layer)

The composition (1) for forming an alignment film was coated on a triacetyl cellulose (TAC) film (manufactured by Konica Minolta Co., ltd., KC4 UY) cut into a rectangular shape, and then dried by heating to form an alignment film having a thickness of 100 nm. The surface of the obtained alignment film was subjected to rubbing treatment at an angle of 15 ° with respect to the longitudinal direction of the TAC film, and the 2 nd liquid crystal composition (2) was applied on the surface by a bar coater. The obtained coating film was dried at 100℃for 1 minute, and then cooled to room temperature to obtain a dried film. Next, the dried film was irradiated with an exposure of 1000mJ/cm under a nitrogen atmosphere using a high-pressure mercury lamp (UNICURE VB-15201BY-A, manufactured BY USHIO Motor Co., ltd.) ² Ultraviolet light (365 nm basis), thereby forming a cured product layer (2-1) of the polymerizable liquid crystal compound obtained by curing the polymerizable liquid crystal compound in a state in which the optical axis of the polymerizable liquid crystal compound is oriented in the horizontal direction with respect to the TAC film surface. Thus, a 2 nd liquid crystal retardation layer (1) with a base material layer comprising a 2 nd base material layer (TAC film)/a 2 nd liquid crystal retardation layer (1) (alignment film/cured product layer (2-1) (horizontally aligned liquid crystal cured film)) was obtained.

The thickness of the cured product layer (2-1) was measured by a laser microscope, and found to be 1. Mu.m. The in-plane retardation value of the 2 nd liquid crystal retardation layer (1) was measured by using KOBRA-WR manufactured by prince measuring instruments Co. As a result, the in-plane phase difference value at the wavelength of 550nm was Re (550) =140 nm. Since the retardation value at the wavelength of 550nm of the TAC film is substantially 0, the TAC film has no influence on the optical characteristics of the 2 nd liquid crystal retardation layer (1). The orientation angle was 75 ° with respect to the long side direction of the TAC film.

[ production of the 1 st liquid Crystal retardation layer (2) ]

(preparation of composition (2) for Forming photo-alignment film)

2 parts of a photo-alignment material having the structure shown below was mixed with 98 parts of cyclopentanone (solvent), and stirred at a temperature of 80 ℃ for 1 hour, thereby obtaining a composition (2) for forming a photo-alignment film. A light-oriented material having the following structure (weight average molecular weight: 50000, m: n=50:50) was synthesized according to the method described in JP-A2021-196514.

Light-oriented material:

[ chemical 18]

(preparation of liquid Crystal composition (3))

The following polymerizable liquid crystal compound (X6), polymerizable liquid crystal compound (X7), leveling agent and photopolymerization initiator were mixed, and N-methyl-2-pyrrolidone (NMP) was then mixed so that the solid content concentration was 13%, and stirred at a temperature of 80 ℃ for 1 hour, thereby preparing liquid crystal composition 2 (3). The polymerizable liquid crystal compound (X6) and the polymerizable liquid crystal compound (X7) have the following structures. The polymerizable liquid crystal compound (X6) was prepared in the same manner as described in Japanese patent application laid-open No. 2019-003177. The polymerizable liquid crystal compound (X7) was prepared in the same manner as described in japanese patent application laid-open No. 2009-173893.

Polymerizable liquid crystal compound (X6): 90 parts of

Polymerizable liquid crystal compound (X7): 10 parts of

Leveling agent [ BYK-361N (manufactured by BM Chemie Co.) ]:0.1 part

Photopolymerization initiator [ IrgacureOXE-03 (BASF JAPAN Co., ltd.) ]:3 parts of

Polymerizable liquid crystal compound (X6):

[ chemical 19]

Polymerizable liquid crystal compound (X7):

[ chemical 20]

/>

1mg of the polymerizable liquid crystal compound (X6) was dissolved in 10mL of chloroform to obtain a solution. For the obtained solution, a measurement sample was added to a measurement cell having an optical path length of 1cm, and the absorption spectrum was measured by setting the measurement sample in an ultraviolet-visible spectrophotometer (manufactured by Shimadzu corporation, "UV-2450"). The wavelength at which the maximum absorbance was reached was read from the obtained absorption spectrum, and as a result, the maximum absorption wavelength λmax in the range of 300 to 400nm was 356nm.

(production of 1 st liquid Crystal phase-difference layer (2) with base layer)

The composition (2) for forming a photo-alignment film was applied to a biaxially oriented polyethylene terephthalate (PET) film (diaface, mitsubishi resin (ltd)) by means of a bar coater. After drying the resulting coating layer at a temperature of 120 ℃ for 2 minutes, it was cooled to room temperature and the coating layer was dried. Subsequently, the dried coating layer was irradiated with polarized ultraviolet light of 100mJ (313 nm standard) using a UV irradiation apparatus (SPOTCURE SP-9; manufactured by USHIO Motor Co., ltd.) to obtain a photo-alignment film (2). The thickness of the photo-alignment film (2) was 100nm as measured by using an ellipsometer M-220 manufactured by Japan light splitting Co.

The 2 nd liquid crystal composition (3) prepared above was coated on the photo-alignment film (2) on the PET film using a bar coater to form a coating layer. The coating layer was dried by heating at 120℃for 2 minutes and then cooled to room temperature. The dried coating layer was irradiated with a high-pressure mercury lamp (UNICURE VB-15201BY-A, manufactured BY USHIO Motor Co.) under a nitrogen atmosphere at an exposure of 500mJ/cm ² Ultraviolet light (365 nm, reference), thereby forming a cured product layer (1-2) of the 2 nd liquid crystal composition (3) obtained by curing the polymerizable liquid crystal compound in a state of being oriented in a horizontal direction with respect to the PET film surface. UsingThe thickness of the cured product layer (1-2) was 2 μm as measured by a laser microscope LEXT OLS4100, manufactured by Olin Bas Co. Thus, a 1 st liquid crystal retardation layer (2) with a base material layer comprising a 2 nd base material layer (PET film)/a 1 st liquid crystal retardation layer (2) (photo-alignment film (2)/cured product layer (1-2)) was obtained.

The 1 st liquid crystal retardation layer (2) side of the 1 st liquid crystal retardation layer (2) having a base material layer was subjected to corona treatment, and the 1 st liquid crystal retardation layer (2) having a base material layer was bonded to glass via a 25 μm pressure-sensitive adhesive manufactured by LINTEC corporation, and a PET film was peeled off to obtain a test body. The in-plane phase difference value of the test body was measured using KOBRA-WR manufactured by prince measuring instruments Co. The in-plane phase difference values for light of wavelengths 450nm, 550nm and 650nm were obtained from the Cauchy dispersion formula obtained from the measurement results of the in-plane phase difference values for light of wavelengths 448.2nm, 498.6nm, 548.4nm, 587.3nm, 628.7nm and 748.6 nm. As a result, the in-plane phase difference values Re (450) =122 nm, re (550) =140 nm, and Re (650) =144 nm, and the relationship between the in-plane phase difference values at the respective wavelengths is as follows.

Re(450)/Re(550)＝0.87

Re(650)/Re(550)＝1.03

[ wherein Re (450) represents the in-plane phase difference value for light having a wavelength of 450nm, re (550) represents the in-plane phase difference value for light having a wavelength of 550nm, and Re (650) represents the in-plane phase difference value for light having a wavelength of 650 nm. ]

[ production of the 2 nd liquid Crystal phase-difference layer (2) ]

(preparation of composition for Forming vertical alignment film)

2-phenoxyethyl acrylate, tetrahydrofurfuryl acrylate, dipentaerythritol triacrylate and bis (2-ethyleneoxyethyl) ether were reacted in an aqueous solution of 1:1:4:5, and then adding a LUCIRIN TPO as a polymerization initiator at a ratio of 4% to prepare a composition for forming a vertical alignment film.

(preparation of liquid Crystal composition (4))

The 2 nd liquid crystal composition (4) was prepared so that the solid content was 1 to 1.5g using a photopolymerizable nematic liquid crystal compound (RMM 28B, manufactured by Merck corporation) and a vehicle. The solvent used was a mixed solvent obtained by mixing Methyl Ethyl Ketone (MEK), methyl isobutyl ketone (MIBK) and Cyclohexanone (CHN), wherein the mass ratio of the Methyl Ethyl Ketone (MEK), methyl isobutyl ketone (MIBK) and Cyclohexanone (CHN) was 35:30: 35.

(production of the 2 nd liquid Crystal phase-difference layer (2) with base layer)

The surface of a polyethylene terephthalate (PET) film (FF-50, manufactured by UNI CHIKA, inc., single-sided release-treated PET film (thickness of supporting substrate: 50 μm)) having a film width of 800mm on the side opposite to the release-treated side was subjected to corona treatment, and then the composition for forming a vertical alignment film prepared above was applied using a slit coater so that the thickness after curing was 3. Mu.m. Irradiating the coating film with 200mJ/cm ² The vertical alignment film was formed on the single-sided release-treated PET film.

The 2 nd liquid crystal composition (4) prepared above was coated on the vertical alignment film on the single-sided release-treated PET film using a slit coater so that the thickness after curing was 1 μm. The drying temperature was 75℃and the drying time was 120 seconds, and after drying the coating layer, ultraviolet (UV) irradiation was performed to polymerize the polymerizable liquid crystal compound to form a cured layer (2-2). Thus, a 2 nd liquid crystal retardation layer (2) with a base material layer comprising a 2 nd base material layer (single-sided release-treated PET film)/a 2 nd liquid crystal retardation layer (2) (vertical alignment film/cured product layer (2-2)) was obtained. The 2 nd liquid crystal phase difference layer (2) is a positive C plate.

[ preparation of active energy ray-curable composition (1) (cationically polymerizable adhesive composition) ]

The following components were mixed and defoamed to prepare an active energy ray-curable composition (1). The photo-cation polymerization initiator was blended in the form of a 50% propylene carbonate solution, and the parts thereof were expressed as the solid content.

Cationic polymerizable Compound (1) [ 3-ethyl-3 { [ (3-ethyloxetan-3-yl) methoxy ] methyl } oxetan (trade name: OXT-221, manufactured by Toyama Synthesis Co., ltd.) ]:60.0 parts of

Cationic polymerizable Compound (2) [3, 4-epoxycyclohexane carboxylic acid 3',4' -epoxycyclohexyl methyl ester (trade name: CEL2021P, (manufactured by Daicel) ]:32.5 parts of

Cationic polymerizable Compound (3) [1, 2-epoxy-4- (2-epoxyethyl) cyclohexane adduct of 2, 2-bis (hydroxymethyl) -1-butanol (trade name: EHPE3150, manufactured by Daicel Co., ltd.): 7.5 parts

Photo cationic polymerization initiator [ CPI-100P (manufactured by San-Apro Co., ltd., 50% by mass solution) ]:2.3 parts of

Photosensitizer [9, 10-dibutoxyanthracene ]:1.0 part

Photosensitive auxiliary [1, 4-diethoxynaphthalene ]:1.0 part

[ preparation of active energy ray-curable composition (2) (radical-polymerizable adhesive composition) ]

The following components were mixed to prepare an active energy ray-curable composition (2).

N, N-dimethylacrylamide [ manufactured by KJ Chemicals Co., ltd. ]:65 parts of

Dicyclopentyl acrylate [ hitachi chemical industry (ltd) ]:15 parts of

Ultraviolet curable urethane acrylate resin [ trade name: UV-3700B, manufactured by Japanese synthetic chemical Co., ltd., viscosity: 30000 to 60000 mPa.s/60 ℃ and molecular weight (Mw): 38000. oligomer functionality number: 2. glass transition temperature Tg: -6 ℃ ]:20 parts of

Photo radical polymerization initiator [ Omnirad 819 (2-methyl-1- [4- (methylthio) phenyl ] -2-morpholinopropan-1-one), BASF JAPAN (ltd) ]:3 parts of

[ production of adhesive layer (1) ]

To a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device and a nitrogen inlet tube, 95.0 parts of n-butyl acrylate, 4.0 parts of acrylic acid, 1.0 parts of 2-hydroxyethyl acrylate, 200 parts of ethyl acetate and 0.08 parts of 2,2' -azobisisobutyronitrile were added, and the air in the reaction vessel was replaced with nitrogen. The reaction solution was heated to 60℃under nitrogen with stirring, reacted for 6 hours, and then cooled to room temperature.

As a result of measuring the weight average molecular weight of a part of the obtained solution, it was confirmed that 180 ten thousand (meth) acrylate polymers were produced. The weight average molecular weight (Mw) of the (meth) acrylic resin is a polystyrene-equivalent weight average molecular weight measured using Gel Permeation Chromatography (GPC) under the following conditions.

[ measurement conditions ]

GPC measurement apparatus: HLC-8020 manufactured by TOSOH Co., ltd

GPC column (passing in the following order): TOSOH Co., ltd

TSK guard column HXL-H

TSK gel GMHXL(×2)

TSK gel G2000HXL

Measuring vehicle: tetrahydrofuran (THF)

Measurement temperature: 40 DEG C

100 parts (solid content equivalent; the same applies hereinafter) of the (meth) acrylate polymer obtained in the above-mentioned step, 1.5 parts of trimethylolpropane-modified toluene diisocyanate (manufactured by TOSOH Co., ltd., trade name "CORONATE (registered trademark) L") as an isocyanate-based crosslinking agent, 0.30 parts of 3-glycidoxypropyl trimethoxysilane (manufactured by Xinyue chemical Co., ltd., trade name "KBM 403") as a silane coupling agent, 7.5 parts of ethoxylated isocyanuric acid triacrylate (manufactured by Xinzhongcun chemical Co., ltd.: product name "A-9300") as an ultraviolet-curable compound, and 0.5 parts of 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one (manufactured by BASF Co., ltd.: irgacure (registered trademark) 907) as a photopolymerization initiator were mixed, and sufficiently stirred, and diluted with ethyl acetate, thereby obtaining a coating solution of the adhesive composition (1).

The release treated surface (release layer) of the spacer (LINTEC: SP-PLR 382190) was coated with the coating solution of the adhesive composition (1) by a coater so that the thickness after drying was 5 μm (measured by a digital micrometer "MH-15M" manufactured by Nikon, inc.), and then dried at 100℃for 1 minute, and the other spacer (LINTEC: SP-PLR 381031) was bonded to the surface of the dried coating layer opposite to the surface to which the spacer was bonded. Using UV-irradiation means with conveyor belt for the coating layer(manufactured by Fusion UV Systems Co., ltd., lamp using D-tube) irradiating ultraviolet rays (irradiation intensity 500 mW/cm) through the release sheet ² Cumulative light quantity 500mJ/cm ² ) And forming an adhesive layer (1) to obtain the adhesive layer (1) with spacers on both sides.

The water vapor permeability of the adhesive layer (1) was measured at 40℃and 90% relative humidity by a water vapor permeability measuring machine (Lyssy-L80-5000, lyssy Co., ltd.), and found to be 7600 g/(m) ² ·24h)。

The storage modulus G' of the adhesive layer (1) was measured, and as a result, it was 125000Pa at a temperature of 25 ℃. The storage modulus G' was measured by laminating a plurality of adhesive layers (1) so that the thickness was 0.2mm (measured by a digital micrometer "MH-15M" manufactured by Nikon, inc.), punching out a cylinder having a diameter of 8mm, and using the obtained material as a sample for measurement, the sample for measurement was measured under the following conditions by a rotary shear method using a viscoelasticity measuring device (manufactured by Physics Co., ltd., MCR 300) in accordance with JIS K7244-6.

[ measurement conditions ]

Normal force FN:1N

Strain γ:1%

Frequency: 1Hz

Temperature: 25 DEG C

The glass transition temperature of the adhesive layer (1) was measured by the following procedure, and as a result, it was 25℃or lower. First, 5mg of the adhesive layer (1) was collected, placed in an aluminum pressure-tight container, and the container was sealed by pressing, thereby preparing a measurement sample. The vessel containing the above measurement sample was set in a Differential Scanning Calorimeter (DSC) [ EXSTAR-6000DSC6220 "sold by SII NANOT ECHNOLOGY Co., ltd.) and cooled from 20℃to-60℃while purging nitrogen gas, and after the temperature reached-60℃for 1 minute, the temperature was raised from-60℃to 150℃at a temperature-raising rate of 10℃per minute, and immediately cooled to 20℃after the temperature reached 150 ℃. Thereafter, the intermediate point glass transition temperature defined in "method for measuring transition temperature of plastics" in JIS K7121-1987 was determined from the DSC curve when the temperature was raised from-60℃to 150℃and was used as the glass transition temperature of the pressure-sensitive adhesive layer (1) to be measured.

[ production of adhesive layers (2) to (6) ]

To a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device and a nitrogen inlet tube, 97.0 parts of n-butyl acrylate, 1.0 parts of acrylic acid, 0.5 parts of 2-hydroxyethyl acrylate, 200 parts of ethyl acetate and 0.08 parts of 2,2' -azobisisobutyronitrile were added, and the air in the reaction vessel was replaced with nitrogen. The reaction solution was heated to 60℃under nitrogen with stirring, reacted for 6 hours, and then cooled to room temperature. The weight average molecular weight of a part of the obtained solution was measured by the above procedure, and as a result, it was confirmed that 180 ten thousand (meth) acrylate polymers were produced.

100 parts (solid content equivalent; the same applies hereinafter) of the (meth) acrylate polymer obtained in the above-described step, 0.30 part of trimethylolpropane-modified toluene diisocyanate (trade name "CORONATE (registered trademark) L" manufactured by TOSOH Co., ltd.) as an isocyanate-based crosslinking agent, and 0.30 part of 3-glycidoxypropyl trimethoxysilane (trade name "KBM403" manufactured by Xinyue chemical Co., ltd.) as a silane coupling agent were mixed, sufficiently stirred, and diluted with ethyl acetate, thereby obtaining a coating solution of the adhesive composition (2).

The release treated surface (release layer) of the spacer (LINTEC Co., ltd.: SP-PLR 382190) was coated with a coating solution of the adhesive composition (2) by a coater so that the thickness after drying was 5 μm (adhesive layer (2)), 10 μm (adhesive layer (3)), 15 μm (adhesive layer (4)), 25 μm (adhesive layer (5)) and 35 μm (adhesive layer (6)) respectively (the thickness was measured by a digital micrometer "MH-15M" manufactured by Nikon Co., ltd.), and then dried at 100℃for 1 minute, and the other spacer (LINTEC Co., ltd.: SP-PLR 381031) was bonded to the surface of the dried coating layer opposite to the surface on which the spacer was bonded, whereby the adhesive layers (2) to (6) with spacers on both sides were obtained.

The storage modulus G 'of the adhesive layers (2) to (6) was measured by the above-mentioned procedure, and as a result, the storage modulus G' was 25500Pa at 25 ℃. The glass transition temperatures of the adhesive layers (2) to (6) were measured by the above-described steps, and as a result, the temperatures were 25℃or lower.

[ example 1 ]

(production of a retardation laminate (1) with a base layer)

The 1 st liquid crystal retardation layer (1) with a base material layer and the 2 nd liquid crystal retardation layer (1) with a base material layer obtained in the above were laminated via the active energy ray-curable composition (1) prepared in the above so that the 1 st liquid crystal retardation layer (1) side and the 2 nd liquid crystal retardation layer (1) side were each a bonding surface. Then, ultraviolet rays were irradiated from the 2 nd liquid crystal retardation layer (1) side with the base layer, and the active energy ray-curable composition (1) was cured to form a 2 nd adhesive layer having a thickness of 2 μm, thereby obtaining a retardation laminate (1) (retardation laminate (1)) with the base layer. The retardation laminate (1) with a base layer has a layer structure of a 2 nd base layer (COP film)/a 1 st liquid crystal retardation layer (1) (alignment film/cured product layer (1-1))/a 2 nd bonding layer (cured product layer of active energy ray-curable composition (1))/a 2 nd liquid crystal retardation layer (1) (cured product layer (2-1)/alignment film)/a 2 nd base layer (TAC film).

(production of optical laminate with spacer (1))

The outer coating side of the polarizing plate (1) with a base material layer cut out so that the longitudinal direction of the long strip is a long side is subjected to corona treatment. Then, the 2 nd base material layer (COP film) on the 1 st liquid crystal retardation layer (1) side of the retardation laminate (1) with a base material layer obtained above was peeled off, and the peeled surface was subjected to corona treatment. The alignment film was peeled off simultaneously with the peeling of the 2 nd base material layer. The corona treated surface is bonded via the active energy ray-curable composition (1) prepared above so that the long sides overlap each other. Then, from the side of the polarizing plate (1) with the base material layer, the cumulative amount of UVA light was about 350mJ/cm ² Ultraviolet light was irradiated to form an active energy ray-curable composition (1) (a measurement value obtained by fusion UV company, UV Power PuckII) and the active energy ray-curable composition (1) was cured to form a 1 st adhesive layer as a cured product layer. The thickness of the 1 st lamination layer was 2. Mu.m.

Then, the adhesive layer (4) exposed by peeling one spacer from the adhesive layer (4) with spacers on both sides is bonded to the surface exposed by peeling the 2 nd base layer (TA C film) of the 2 nd liquid crystal retardation layer (1) with base layer, and the single-sided release-treated PET film on the polarizing plate (1) side with base layer is peeled off to obtain the optical laminate (1) with spacers. The alignment film was peeled off simultaneously with the peeling of the 2 nd base material layer. The optical laminate (1) with a spacer has a layer structure of a protective layer (HC layer)/a liquid crystal polarizing plate (photo-alignment film (1)/a cured product layer)/an overcoat layer/a 1 st lamination layer (cured product layer of an active energy ray-curable composition (1))/a 1 st liquid crystal retardation layer (1) (cured product layer (1-1))/a 2 nd lamination layer (cured product layer of an active energy ray-curable composition (1))/a 2 nd liquid crystal retardation layer (1) (cured product layer (2-1))/a 3 rd lamination layer (adhesive layer (4))/a spacer.

[ examples 2 to 4 ]

A retardation laminate (2) with a base layer (retardation body (2)) was obtained using the contents shown in table 2 as the 2 nd bonding layer. The contents shown in Table 2 were used as the 1 st bonding layer and the 3 rd bonding layer, and in order to cure the active energy ray-curable composition (2) interposed between the polarizing plate with substrate layer (1) and the retardation laminate with substrate layer (1), the cumulative amount of UVB light was about 250mJ/cm ² Optical laminates (2) to (4) with spacers were obtained in the same manner as in example 1, except that ultraviolet light was irradiated to the substrate (using a measuring instrument: a measured value obtained by fusion UV Power PuckII).

[ example 5 ]

(production of a retardation laminate (5) with a base layer)

The 1 st liquid crystal retardation layer (2) with a base material layer and the 2 nd liquid crystal retardation layer (2) with a base material layer obtained in the above were laminated via the active energy ray-curable composition (1) prepared in the above so that the 1 st liquid crystal retardation layer (2) side and the 2 nd liquid crystal retardation layer (2) side were each a bonding surface. Then, ultraviolet rays were irradiated from the 2 nd liquid crystal retardation layer (2) side with the base layer, and the active energy ray-curable composition (1) was cured to form a 2 nd adhesive layer having a thickness of 2 μm, thereby obtaining a retardation laminate (5) (retardation laminate (5)) with the base layer. The retardation laminate (5) with a base layer has a layer structure of a 2 nd base layer (PET film)/a 1 st liquid crystal retardation layer (2) (photo-alignment film (2)/cured product layer (1-2))/a 2 nd lamination layer (cured product layer of active energy ray-curable composition (1)/a 2 nd liquid crystal retardation layer (2) (cured product layer (2-2)/a vertical alignment film)/a 2 nd base layer (single-sided release-treated PET film).

(production of optical laminate with spacer (5))

The procedure of example 1 for producing the optical layered body with spacer (1) was used to obtain the optical layered body with spacer (5), except that the optical layered body with spacer (5) was used instead of the optical layered body with base layer (1). In the peeling of the 2 nd base material layer (PET film and single-sided release PET film) of the phase difference laminate (5) with a base material layer, the 2 nd base material layer is peeled off, and the photo-alignment film (2) and the vertical alignment film are not peeled off, but remain on the cured product layer (1-2) and the cured product layer (2-2), respectively. The optical laminate (5) with a spacer has a layer structure of a protective layer (HC layer)/a liquid crystal polarizing plate (photo-alignment film (1)/a cured product layer)/an overcoat layer/a 1 st lamination layer (cured product layer of an active energy ray-curable composition (1))/a 1 st liquid crystal retardation layer (2) (photo-alignment film (2)/a cured product layer (1-2))/a 2 nd lamination layer (cured product layer of an active energy ray-curable composition (1)/a 2 nd liquid crystal retardation layer (2) (cured product layer (2-2)/a vertical alignment film)/a 3 rd lamination layer (adhesive layer (4))/a spacer.

Examples 6 to 8

Using the contents shown in Table 3 as the polarizing plate with a base layer, the 1 st adhesive layer, the 2 nd adhesive layer and the 3 rd adhesive layer, the active energy ray-curable composition (2) interposed between the polarizing plate with a base layer and the retardation laminate with a base layer was cured so that the cumulative amount of UVB light was about 250mJ/cm ² Optical laminates (6) to (8) with spacers were obtained in the same manner as in example 5, except that ultraviolet light was irradiated to the substrate (using a measuring instrument: a measured value obtained by UV Power PuckI I manufactured by fusion UV).

[ example 9 ]

An optical laminate with spacers (9) was obtained in the same manner as in example 2, except that the adhesive layer with spacers (6) was used instead of the adhesive layer with spacers (3).

Comparative example 1

(production of a retardation laminate (c 1) with a base layer)

Corona treatment is performed on the 1 st liquid crystal retardation layer side (1) of the 1 st liquid crystal retardation layer (1) with a base material layer and the 2 nd liquid crystal retardation layer (1) side of the 2 nd liquid crystal retardation layer (1) with a base material layer obtained in the above. The corona treated surface is bonded to the pressure-sensitive adhesive layer (1) obtained by peeling off the spacers of the pressure-sensitive adhesive layer (1) with spacers on both surfaces, to obtain a retardation laminate (c 1) (retardation (c 1)) with a base layer. The retardation laminate (c 1) with a base layer has a layer structure of a 2 nd base layer (COP film)/a 1 st liquid crystal retardation layer (1) (alignment film/cured product layer (1-1))/a 2 nd adhesive layer (1))/a 2 nd liquid crystal retardation layer (1) (cured product layer (2-1)/alignment film)/a 2 nd base layer (TAC film).

(production of optical laminate with spacer (c 1))

The outer coating side of the polarizing plate (1) with a base material layer cut out so that the longitudinal direction of the long strip is a long side is subjected to corona treatment. Then, the 2 nd base material layer (COP film) on the 1 st liquid crystal retardation layer (1) side of the retardation laminate with base material layer (c 1) obtained above was peeled off, and the peeled surface was subjected to corona treatment. The alignment film was peeled off simultaneously with the peeling of the 2 nd base material layer. The corona treated surface is bonded via the active energy ray-curable composition (1) prepared above so that the long sides overlap each other. Then, from the side of the polarizing plate (1) with the base material layer, the cumulative amount of UVA light was about 350mJ/cm ² Ultraviolet light was irradiated to form an active energy ray-curable composition (1) (a measurement value obtained by fusion UV company, UV Power PuckII) and the active energy ray-curable composition (1) was cured to form a 1 st adhesive layer as a cured product layer. The thickness of the 1 st lamination layer was 2. Mu.m.

Thereafter, the adhesive layer (5) exposed by peeling one spacer from the adhesive layer (5) with spacers on both sides was bonded to the surface exposed by peeling the 2 nd base layer (TA C film) of the 2 nd liquid crystal retardation layer (1) with base layer, and the single-sided release-treated PET film on the polarizing plate (1) side with base layer was peeled off to obtain an optical laminate (C1) with spacers. The alignment film was peeled off simultaneously with the peeling of the 2 nd base material layer. The spacer-equipped optical laminate (c 1) has a layer structure of a protective layer (HC layer)/a liquid crystal polarizing plate (photo-alignment film (1)/a cured product layer)/an overcoat layer/a 1 st lamination layer (a cured product layer of an active energy ray-curable composition (1)/a 1 st liquid crystal retardation layer (1) (a cured product layer (1-1))/a 2 nd lamination layer (adhesive layer (1))/a 2 nd liquid crystal retardation layer (1) (a cured product layer (2-1))/a 3 rd lamination layer (adhesive layer (5))/a spacer.

Comparative example 2

(production of a retardation laminate (c 2) with a base layer)

Corona treatment is performed on the 1 st liquid crystal retardation layer side (2) of the 1 st liquid crystal retardation layer (2) with a base material layer and the 2 nd liquid crystal retardation layer (2) side of the 2 nd liquid crystal retardation layer (2) with a base material layer obtained in the above. The pressure-sensitive adhesive layer (1) obtained by peeling the spacers of the pressure-sensitive adhesive layer (1) with spacers on both sides is bonded to the corona-treated surface, and a phase difference laminate (c 2) (phase difference body (c 2)) with a base layer is obtained. The retardation laminate (c 2) with a base layer has a layer structure of a 2 nd base layer (PET film)/a 1 st liquid crystal retardation layer (2) (photo-alignment film (2)/cured product layer (1-2))/a 2 nd adhesive layer (1))/a 2 nd liquid crystal retardation layer (2) (cured product layer (2-2)/a vertical alignment film)/a 2 nd base layer (single-sided release-treated PET film).

(production of optical laminate with spacer (c 2))

The outer coating side of the polarizing plate (1) with a base material layer obtained above was subjected to corona treatment. Then, the 2 nd base material layer (PET film) on the 1 st liquid crystal retardation layer (2) side of the retardation laminate with base material layer (c 2) obtained above was peeled off, and the peeled surface was subjected to corona treatment. In the peeling of the 2 nd base layer, the PET film is peeled off, and the photo-alignment film (2) is not peeled off but remains on the cured product layer (1-2). The corona treated surface is bonded to the pressure-sensitive adhesive layer (1) by peeling off the spacers of the pressure-sensitive adhesive layer (1) with spacers on both surfaces.

Then, the adhesive layer (5) exposed by peeling one spacer from the adhesive layer (5) with spacers on both sides is bonded to the surface exposed by peeling the 2 nd base layer of the 2 nd liquid crystal retardation layer (2) with base layer, and the single-sided release-treated PET film on the polarizing plate (1) side with base layer is peeled off to obtain an optical laminate (c 2) with spacers. The PET film was peeled off by the single-sided release treatment due to peeling of the 2 nd base layer, and the vertical alignment film was not aligned but remained on the cured layer (2-2). The spacer-equipped optical laminate (c 2) has a layer structure of a protective layer (HC layer)/liquid crystal polarizing plate (photo-alignment film (1)/cured product layer)/overcoat layer/1 st adhesive layer (1))/1 st liquid crystal retardation layer (2) (photo-alignment film (2)/cured product layer (1-2))/2 nd adhesive layer (1))/2 nd liquid crystal retardation layer (2) (cured product layer (2-2)/homeotropic alignment film)/3 rd adhesive layer (5))/spacer.

[ comparative example 3 ]

(preparation of adhesive composition)

The following components were mixed and defoamed to prepare a cationic polymerization type adhesive composition. The cationic polymerization initiator was compounded in the form of a 50 mass% propylene carbonate solution, showing the solid content amount thereof.

1, 6-hexanediol diglycidyl ether (EX-212L, manufactured by Nagase ChemteX Co., ltd.): 25 parts of

4-hydroxybutyl vinyl ether: 10 parts of

Bisphenol F type epoxy resin (EXA-830 CRP, DIC Co., ltd.): 65 parts of

Cationic polymerization initiator (CPI-100P, san-Apro (product of Apro Co., ltd., 50% by mass solution): 3 parts of

(production of a retardation laminate (c 3) with a base layer)

The 1 st liquid crystal retardation layer (2) with a base material layer and the 2 nd liquid crystal retardation layer (2) with a base material layer obtained in the above were laminated via the active energy ray-curable composition (1) prepared in the above so that the 1 st liquid crystal retardation layer side (2) and the 2 nd liquid crystal retardation layer (2) side were each a bonding surface. Then, ultraviolet rays were irradiated from the 2 nd liquid crystal retardation layer (2) side with the base layer, and the active energy ray-curable composition (1) was cured to form a 2 nd adhesive layer having a thickness of 2 μm, thereby obtaining a retardation laminate (c 3) with the base layer (retardation body (c 3)). The retardation laminate (c 3) with a base layer has a layer structure of a 2 nd base layer (PET film)/a 1 st liquid crystal retardation layer (2) (photo-alignment film (2)/cured product layer (1-2))/a 2 nd lamination layer (cured product layer of active energy ray-curable composition (1)/a 2 nd liquid crystal retardation layer (2) (cured product layer (2-2)/a vertical alignment film)/a 2 nd base layer (single-sided release-treated PET film).

(production of optical laminate with spacer (c 3))

The outer coating side of the polarizing plate (1) with a base material layer obtained above was subjected to corona treatment. Then, the 2 nd base material layer (PET film) on the 1 st liquid crystal retardation layer (2) side of the retardation laminate with base material layer (c 3) obtained above was peeled off, and the peeled surface was subjected to corona treatment. In the peeling of the 2 nd base layer, the PET film is peeled off, and the photo-alignment film (2) is not peeled off but remains on the cured product layer (1-2). The corona treated surface is bonded to the pressure-sensitive adhesive layer (1) by peeling off the spacers of the pressure-sensitive adhesive layer (1) with spacers on both surfaces, thereby obtaining a laminated structure (c 3).

The surface of a cycloolefin polymer (COP) film (ZEON Co., ltd., ZF 14) having a thickness of 13.00 μm exposed by stripping the single-sided release-treated PET film on the polarizing plate (1) side of the laminated structure (c 3) obtained as described above was subjected to corona treatment. The corona-treated surface was bonded via the adhesive composition prepared as described above, and the surface was irradiated with an ultraviolet irradiation device (SPOTCURESP-7, manufactured by USHIO Motor Co., ltd.) at an exposure of 500mJ/cm ² Ultraviolet rays (365 nm basis) were used to form an adhesive layer having a thickness of 2.00. Mu.m. Ultraviolet rays were irradiated from the COP film side. Then, the adhesive layer (4) exposed by peeling one spacer from the adhesive layer (4) with spacers on both sides is bonded to the surface exposed by peeling the 2 nd base layer of the 2 nd liquid crystal retardation layer (2) with base layer, thereby obtaining an optical laminate (c 3) with spacers. Due to the peeling of the 2 nd base material layer, the single-sided release-treated PET film was peeled off, and the homeotropic alignment film was not aligned, but Is left on the cured product layer (2-2). The spacer-equipped optical laminate (c 3) has a layer structure of a protective layer (COP film/adhesive layer/HC layer)/liquid crystal polarizer (photo-alignment film (1)/cured product layer)/overcoat layer/1 st bonding layer (adhesive layer (1))/1 st liquid crystal retardation layer (2) (photo-alignment film (2)/cured product layer (1-2))/2 nd bonding layer (cured product layer of active energy ray-curable composition (1)/2 nd liquid crystal retardation layer (2) (cured product layer (2-2)/vertical alignment film)/3 rd bonding layer (adhesive layer (4))/spacer.

[ comparative example 4 ]

A triacetyl cellulose (TAC) film (KC 2CT, manufactured by Konica Minolta corporation) having a thickness of 20.00 μm was used instead of the COP film, and the TAC film was bonded to the surface exposed by peeling the single-sided release-treated PET film from the laminated structure (c 3), and the optical laminate with a spacer (c 4) was obtained by the step of producing the optical laminate with a spacer (c 3) of comparative example 3 except that ultraviolet light was irradiated from the TAC film side.

[ calculation of the ratio of the thickness of the adhesive layer (Dt/D1) ]

The thickness ratio [% ] (=dt/d1×100) is calculated by setting D1 (fig. 1) as the distance from the surface of the protective layer on the opposite side from the liquid crystal polarizer side to the surface of the 3 rd bonding layer on the opposite side from the 2 nd liquid crystal retardation layer side, and Dt as the total thickness of the layers (adhesive layers) having Tg of 25 ℃ or less in the 1 st bonding layer, the 2 nd bonding layer, and the 3 rd bonding layer. The cured product layer of the active energy ray-curable composition (1) and the cured product layer of the active energy ray-curable composition (2) were measured by the above-described procedure, and as a result, both were higher than 25 ℃. In the embodiment, the total thickness Dt is the thickness D2 (fig. 1) of the 3 rd bonding layer. The results are shown in tables 2 to 5.

[ impact resistance test ]

The 3 rd lamination layer exposed by peeling the spacer of the optical laminate with a spacer obtained in the above was laminated with alkali-free glass (manufactured by Corning corporation, EAGLE XG (registered trademark), thickness 0.7 mm) to prepare a test sample. Impact resistance test was performed by dropping a weight from a height of 5cm onto the surface of the test sample on the optical laminate side (surface on the protective layer side). The weight was a spherical body having a mass of 4.6g and a diameter of 0.75mm at the point of collision with the surface of the optical laminate, and made of stainless steel. The test sample after the impact resistance test was observed from the optical laminate (protective layer) side, the presence or absence of cracks at the dropping portion of the weight and the periphery thereof was confirmed, and when the cracks were present, the size of the cracks was measured and evaluated according to the following criteria. The size of the crack is set to be the diameter of a perfect circle of the inscribed crack in the top view of the protective layer. The results are shown in tables 2 to 5.

A: no cracks were observed.

B: cracks of a size smaller than 200 μm were observed.

C: cracks of 200 μm or more in size were observed.

[ scratch test ]

Using the optical laminate with spacers obtained above, a test sample was produced by the procedure described in the impact resistance test, after 1 hour from the formation of the 2 nd adhesive layer, and after 30 minutes from the formation of the 1 st adhesive layer between the polarizing plate and the 1 st liquid crystal retardation layer. A5N load was applied to the surface of the test sample on the optical laminate side (surface on the protective layer side) by a scratch hardness tester (model 318, manufactured by German Instrument force Co., ltd., ball diameter 0.75 mm), and the load was pressed and moved on the surface at a speed of 1 cm/s. Thereafter, the protective layer side of the optical laminate of the test sample was observed from the front and oblique directions under the conditions of illuminance and reflection glare of the fluorescent lamp shown in table 1, and the evaluation was performed based on the criteria shown in table 1 below, based on the presence or absence of scratch. The results are shown in tables 2 to 5.

TABLE 1

Bending test (1): evaluation of reflection tone ]

From the optical laminate with spacers obtained above, a test piece of rectangular small pieces 110mm long by 10mm short was cut out using a super cutter so that the absorption axis of the liquid crystal polarizer was parallel to the long side.

As shown in fig. 2 (a), in the bending test machine having two jigs 501 and 502 capable of moving independently, the ends of the long sides of the test piece 500 are fixed to the jigs 501 and 502 with adhesive tapes, respectively, in a state in which the test piece 500 is bent such that the protective layer side of the test piece 500 is the inner side and the bending axis is parallel to the short sides, and the positions of the jigs 501 and 502 are adjusted such that the interval L between the jigs 501 and 502 is 70mm. Thereafter, as shown in fig. 2B, the test piece 500 was further bent by moving the jig 501 in the direction of arrow a so that the distance L was 4.0mm (bending radius 2R), and thereafter, the distance L was restored to 70mm by moving the jig 501 in the direction of arrow B, and this series of operations was counted as 1 time, and the above operations were continuously repeated 10 ten thousand times under an environment of 25 ℃ and 55% relative humidity. The movement speed of the jig 501 was 1.32 m/sec, and the time required for repeating the above-described operation of changing the interval L10 ten thousand times was 27.8 hours. After repeating the above operation for 10 ten thousand times, the test piece 500 was taken out from the bending tester, the bending of the test piece 500 was released, the separator was peeled off to expose the 3 rd lamination layer, and the aluminum deposition film side of the PET film (trade name "#50dms (X42)") with an aluminum deposition film was laminated on the exposed surface thereof to prepare a laminated body. The presence or absence of uneven reflection color at a portion along the bending axis was confirmed from the protective layer side of the bonded body in front view, and the evaluation was performed according to the following criteria. The results are shown in tables 2 to 5.

A: no unevenness in the reflection tone was observed.

B: the unevenness of the reflection tone is not noticeable, but can be observed.

C: the unevenness of the reflection tone is conspicuous.

Bending test (2): evaluation of peeling of the No. 3 adhesive layer

From the optical laminate with spacers obtained above, rectangular chips having a long side of 110mm×a short side of 10mm were cut out using a super cutter so that the absorption axis of the liquid crystal polarizer was parallel to the long side. The 3 rd bonding layer was exposed by peeling the spacer from the die, and a PET film (trade name "#50dms (X42)") with an aluminum vapor deposited film was bonded to the exposed surface thereof to prepare a test piece.

The bending test machine used in the bending test (1) was used in addition to the test piece, and the operation of changing the interval L was repeated 10 ten thousand times under the conditions described in the bending test (1). After repeating the above operation for 10 ten thousand times, the bending of the test piece taken out from the bending tester was released, and the presence or absence of peeling of the 3 rd bonding layer was confirmed from the protective layer side of the test piece as viewed from the front, and evaluation was performed in accordance with the following criteria. In the case where peeling occurs in the 3 rd lamination layer, since peeling occurs from the end portion of the test piece, the magnitude of peeling is set to the shortest distance from the end portion of the test piece from which peeling occurs to the side opposite to the end portion side of the test piece from which peeling occurs. The results are shown in tables 2 to 5.

A: no peeling of the 3 rd lamination layer was confirmed.

B: peeling of the 3 rd lamination layer having a size of less than 100 μm was confirmed.

C: the peeling of the 3 rd bonding layer was confirmed to be 100 μm or more in size.

[ workability test ]

The surface protective film was attached to the surface of the protective layer side of the optical laminate with spacers obtained in the above, and the surface protective film was cut into a rectangle so that the absorption axis of the liquid crystal polarizer was +45° with respect to the long side, and a sample for processing was prepared. The surface protective film is bonded so as to be peelable from the protective layer, and is a film that can be peeled off while maintaining the shape of the optical laminate with the spacer.

In the workability test, the polishing was performed using an end face processing apparatus, and the presence or absence of cracks in the 1 st liquid crystal retardation layer and the 2 nd liquid crystal retardation layer, which were generated in the polished end face, was observed. The end face processing apparatus will be described with reference to fig. 3. Fig. 3 is a schematic perspective view schematically showing an end face processing apparatus. In the end face processing apparatus, the polishing of the laminate W of the processing sample can be performed by an apparatus including the support portion 50 and 2 rotary tools 60. The support portion 50 is a member for pressing and fixing the laminate W from above and below so that the laminate W itself does not move during polishing and the laminated processing samples do not shift. The rotary tool 60 is a member for polishing the end surface of the laminate W, and is rotatable about the rotation axis R. The support portion 50 may include a flat plate-like substrate (moving mechanism of the laminate W) 51; a door-shaped frame 52 disposed on the substrate 51; a turntable 53 disposed on the substrate 51 and rotatable about a central axis; a column 54 provided on the frame 52 at a position facing the turntable 53 and capable of moving up and down. The laminate W is held and fixed by a turntable 53 and a column 54 via a clamp 55. On both sides of the substrate 51, 2 rotary tools 60 are provided facing each other. The rotating tool 60 is matched to the size of the laminate W and movable in the direction along the rotation axis R, and the substrate 51 is movable between 2 rotating tools 60. In the polishing process, the laminate W is fixed to the support 50, and after the position of the rotary tool 60 in the rotation axis direction is appropriately adjusted, the substrate 51 is moved so that the laminate W passes between the rotary tools 60 facing each other while rotating the rotary tools 60 around their rotation axes R. This makes it possible to perform polishing by bringing the polishing blade of the rotary tool 60 into contact with the exposed end surfaces of the laminate W facing each other and polishing the end surfaces of the laminate W while relatively moving the rotary tool 60 with respect to the laminate W in a direction parallel to the end surfaces of the laminate W and orthogonal to the lamination direction.

Using the end face processing apparatus shown in fig. 3, the sample for processing was polished into a rectangular shape of 120mm×50mm (in plan view) under the polishing conditions shown below.

Number of laminated sheets of the sample for processing at the time of polishing: 100 pieces

Clamping pressure of laminate W subjected to polishing from both sides: 0.1MPa

Relative movement speed between the laminate W and the rotary tool 60: 3500mm/min

Rotational speed of rotary tool 60: 5400rpm

The feeding step distance (a value obtained by dividing the relative movement speed by the rotation speed of the rotary tool 60 and the number of times the grinding blade contacts the end face when the rotary tool 60 rotates for 1 week): 0.32mm

Direction of entry of the abrasive blade: the direction of the polishing blade from the spacer side toward the surface protection film side into the end face of the sample for processing

The 3 rd lamination layer exposed by peeling the spacer from the sample for processing after polishing was laminated with an aluminum vapor deposited PET film (trade name "#50dms (X42)", manufactured by Toray film processing company) on the aluminum vapor deposited film surface side to prepare a laminate. The laminate was evaluated from the protective layer side by using an optical microscope VHX-1000 (manufactured by Keyence corporation) in accordance with the following criteria. The size of the crack is set to be the diameter of a perfect circle of the inscribed crack in the top view of the protective layer. The results are shown in tables 2 to 5.

A: no cracks were observed.

B: cracks of a size smaller than 200 μm were observed.

C: cracks of 200 μm or more in size were observed.

TABLE 2

	Example 1	Example 2	Example 3	Example 4
					Optical laminate with spacer	(1)	(2)	(3)	(4)
Polarizing plate with base material layer	(1)	(1)	(1)	(1)
					Protective layer
Film/adhesive layer [ mu ] m]	-	-	-	-
					HC layer [ mu ] m]	2.00	2.00	2.00	2.00
Layer structure of liquid crystal polarizer	Oriented film/cured layer	Oriented film/cured layer	Oriented film/cured layer	Oriented film/cured layer
					Thickness [ mu ] m]	0.05/3 ^*3	0.05/3 ^*3	0.05/3 ^*3	0.05/3 ^*3
Overcoat [ mu ] m]	2	2	2	2
					1 st bonding layer
Species of type	Cations (cationic) ^*1	Free radicals ^*2	Free radicals ^*2	Free radicals ^*2
					Thickness [ mu ] m]	2	2	2	2
1 st liquid crystal retardation layer
					Layer structure	Cured product layer	Cured product layer	Cured product layer	Cured product layer
Thickness [ mu ] m]	2	2	2	2
					Layer 2
Species of type	Cations (cationic) ^*1	Free radicals ^*2	Free radicals ^*2	Free radicals ^*2
					Thickness [ mu ] m]	2	2	2	2
2 nd liquid crystal retardation layer
					Layer structure	Cured product layer	Cured product layer	Cured product layer	Cured product layer
Thickness [ mu ] m]	1	1	1	1
					Lamination layer 3
Species of type	Adhesive layer (4)	Adhesive layer (3)	Adhesive layer (4)	Adhesive layer (5)
					Thickness [ mu ] m]	15	10	15	25
Thickness ratio Dt/D1[%]	52	42	52	64
					Evaluation
Impact resistance test	A	A	A	A
					Scratch test	B	A	A	A
Bending test
					Reflection tone	A	A	A	A
Peeling off the 3 rd lamination layer	A	B	A	A
					Workability test	A	A	A	A

*1: cured product layer of cation polymerizable adhesive composition (active energy ray-curable composition (1))

*2: cured product layer of radical polymerizable adhesive composition (active energy ray-curable composition (2))

*3: when the layer structure is a/b, the thickness of a/b is indicated.

TABLE 3

	Example 5	Example 6	Example 7	Example 8
					Optical laminate with spacer	(5)	(6)	(7)	(8)
Polarizing plate with base material layer	(1)	(2)	(3)	(1)
					Protective layer
Film/adhesive layer [ mu ] m]	-	-	-	-
					HC layer [ mu ] m]	2.00	3.95	4.95	2.00
Layer structure of liquid crystal polarizer	Oriented film/cured layer	Oriented film/cured layer	Oriented film/cured layer	Oriented film/cured layer
					Thickness [ mu ] m]	0.05/3 ^*3	0.05/3 ^*3	0.05/3 ^*3	0.05/3 ^*3
Overcoat [ mu ] m]	2	2	2	2
					1 st bonding layer
Species of type	Cations (cationic) ^*1	Free radicals ^*2	Free radicals ^*2	Free radicals ^*2
					Thickness [ mu ] m]	2	2	2	2
1 st liquid crystal retardation layer
					Layer structure	Oriented film/cured layer	Oriented film/cured layer	Oriented film/cured layer	Oriented film/cured layer
Thickness [ mu ] m]	0.1/2 ^*3	0.1/2 ^*3	0.1/2 ^*3	0.1/2 ^*3
					Layer 2
Species of type	Cations (cationic) ^*1	Free radicals ^*2	Free radicals ^*2	Free radicals ^*2
					Thickness [ mu ] m]	2	2	2	2
2 nd liquid crystal retardation layer
					Layer structure	Cured product layer/orientation film	Cured product layer/orientation film	Cured product layer/orientation film	Cured product layer/orientation film
Thickness [ mu ] m]	1/3 ^*3	1/3 ^*3	1/3 ^*3	1/3 ^*3
					Lamination layer 3
Species of type	Adhesive layer (4)	Adhesive layer (4)	Adhesive layer (4)	Adhesive layer (2)
					Thickness [ mu ] m]	15	15	15	5
Thickness ratio Dt/D1[%]	47	44	43	23
					Evaluation
Impact resistance test	A	A	A	A
					Scratch test	B	A	A	A
Bending test
					Reflection tone	A	A	B	A
Peeling off the 3 rd lamination layer	A	A	A	C
					Workability test	A	A	A	A

*3: when the layer structure is a/b, the thickness of a/b is indicated.

TABLE 4

	Example 9	Comparative example 1
			Optical laminate with spacer	(9)	(c1)
Polarizing plate with base material layer	(1)	(1)
			Protective layer
Film/adhesive layer [ mu ] m]	-	-
			HC layer [ mu ] m]	2.00	2.00
Layer structure of liquid crystal polarizer	Oriented film/cured layer	Oriented film/cured layer
			Thickness [ mu ] m]	0.05/3 ^*3	0.05/3 ^*3
Overcoat [ mu ] m]	2	2
			1 st bonding layer
Species of type	Free radicals ^*2	Cations (cationic) ^*1
			Thickness [ mu ] m]	2	2
1 st liquid crystal retardation layer
			Layer structure	Cured product layer	Cured product layer
Thickness [ mu ] m]	2	2
			Layer 2
Species of type	Free radicals ^*2	Adhesive layer (1)
			Thickness [ mu ] m]	2	5
2 nd liquid crystal retardation layer
			Layer structure	Cured product layer	Cured product layer
Thickness [ mu ] m]	1	1
			3 rd plasterLaminated layer
Species of type	Adhesive layer (6)	Adhesive layer (5)
			Thickness D2[ mu ] m]	35	25
Thickness ratio Dt/D1[%]	71	71
			Evaluation
Impact resistance test	A	B
			Scratch test	A	C
Bending test
			Reflection tone	A	A
Peeling off the 3 rd lamination layer	A	A
			Workability test	B	B

*3: when the layer structure is a/b, the thickness of a/b is indicated.

TABLE 5

	Comparative example 2	Comparative example 3	Comparative example 4
				Optical laminate with spacer	(c2)	(c3)	(c4)
Polarizing plate with base material layer	(1)	(1)	(1)
				Protective layer
Film/adhesive layer [ mu ] m]	-	13.00/2.00 ^*3	20.00/2.00 ^*3
				HC layer [ mu ] m]	2.00	2.00	2.00
Layer structure of liquid crystal polarizer	Oriented film/cured layer	Oriented film/cured layer	Oriented film/cured layer
				Thickness [ mu ] m]	0.05/3 ^*3	0.05/3 ^*3	0.05/3 ^*3
Overcoat [ mu ] m]	2	2	2
				1 st bonding layer
Species of type	Adhesive layer (1)	Adhesive layer (1)	Adhesive layer (1)
				Thickness [ mu ] m]	5	5	5
1 st liquid crystal retardation layer
				Layer structure	Oriented film/cured layer	Oriented film/cured layer	Oriented film/cured layer
Thickness [ mu ] m]	0.1/2 ^*3	0.1/2 ^*3	0.1/2 ^*3
				Layer 2
Species of type	Adhesive layer (1)	Cations (cationic) ^*1	Cations (cationic) ^*1
				Thickness [ mu ] m]	5	2	2
2 nd liquid crystal retardation layer
				Layer structure	Cured product layer/orientation film	Cured product layer/orientation film	Cured product layer/orientation film
Thickness [ mu ] m]	1/3 ^*3	1/3 ^*3	1/3 ^*3
				Lamination layer 3
Species of type	Adhesive layer (5)	Adhesive layer (4)	Adhesive layer (4)
				Thickness [ mu ] m]	25	15	15
Thickness ratio Dt/D1[%]	73	40	35
				Evaluation
Impact resistance test	C	B	B
				Scratch test	C	A	A
Bending test
				Reflection tone	A	B	C
Peeling off the 3 rd lamination layer	A	B	C
				Workability test	C	A	A

*3: when the layer structure is a/b, the thickness of a/b is indicated.

Claims

1. An optical laminate comprising, in order, a protective layer, a liquid crystal polarizing plate, a 1 st bonding layer, a 1 st liquid crystal retardation layer, a 2 nd bonding layer, a 2 nd liquid crystal retardation layer, and a 3 rd bonding layer,

the liquid crystal polarizer comprises a cured layer of a 1 st liquid crystal composition containing a dichroic dye and a polymerizable liquid crystal compound,

the 1 st liquid crystal phase difference layer and the 2 nd liquid crystal phase difference layer each include a cured layer of a 2 nd liquid crystal composition containing a polymerizable liquid crystal compound.

2. The optical stack according to claim 1, wherein,

the 1 st bonding layer is a cured layer of the radical polymerizable adhesive composition.

3. The optical laminate according to claim 1 or 2, wherein,

the 2 nd bonding layer is a cured layer of the radical polymerizable adhesive composition.

4. The optical laminate according to claim 1 or 2, wherein,

the thickness of the protective layer, the liquid crystal polarizer, the 1 st liquid crystal phase difference layer and the 2 nd liquid crystal phase difference layer is less than 20.0 μm.

5. The optical laminate according to claim 1 or 2, wherein,

the glass transition temperature of the 3 rd bonding layer is below 25 ℃.

6. The optical stack according to claim 5, wherein,

when the distance from the surface of the protective layer on the opposite side of the liquid crystal polarizer to the surface of the 3 rd lamination layer on the opposite side of the 2 nd liquid crystal retardation layer is set to D1,

the thickness D2 of the 3 rd lamination layer is more than 40% and less than 70% of D1,

the units of D1 and D2 are μm.

7. The optical laminate according to claim 1 or 2, further comprising an overcoat layer covering a surface of the 1 st lamination layer side of the liquid crystal polarizer.