JP2021117500A - Optical laminate - Google Patents

Abstract

To provide an optical laminate having a retardation layer with small Martens hardness, which can be expected to suppress deterioration in optical characteristics, an optical laminate with a laminating layer, and a manufacturing method thereof.SOLUTION: An optical laminate has a polarizing plate having a protective layer on one or both sides of a linearly polarizing layer, a first retardation layer, and a second retardation layer in this order. The first retardation layer comprises a first liquid crystal layer which is a cured product layer of a polymerizable liquid crystal compound, and the second retardation layer comprises a second liquid crystal layer which is a cured product layer of a polymerizable liquid crystal compound. The Martens hardness H1 of the second retardation layer at a pressurization rate of 1 mN/5 s and a creep time of 5 s is 10 N/mm2 or less. A ratio (H2/H1) of the Martens hardness H2 to the Martens hardness H1 at a pressurizing speed of 1 mN/5 s and a creep time of 5 s on the second retardation layer side of the optical laminate is 15 or more.SELECTED DRAWING: Figure 1

Description

The present invention relates to an optical laminate, an optical laminate with a laminated layer, and a method for producing the same.

Organic EL display devices that use organic light emitting diodes (OLEDs) are not only lighter and thinner than liquid crystal displays, but also have a wide viewing angle, fast response speed, high contrast, and other high image quality. Because it can be realized, it is used in various fields such as smartphones, televisions, and digital cameras. It is known that an organic EL display device improves antireflection performance by using a circular polarizing plate or the like in which a linearly polarized light layer and a retardation layer are laminated in order to suppress a decrease in visibility due to reflection of external light. There is.

For example, Patent Document 1 discloses that a liquid crystal layer having a phase difference characteristic is formed by curing a liquid crystal material, and a laminated body in which the liquid crystal layers are laminated is formed. In Patent Document 1, when the laminated body is wound, the outermost layer of the laminated body may be damaged, and in order to effectively avoid this damage, a pencil of a liquid crystal layer or an alignment film constituting the outermost layer of the laminated body. It is disclosed to increase the hardness.

Japanese Unexamined Patent Publication No. 2015-34851

Depending on the type of retardation layer including the liquid crystal layer formed by curing the liquid crystal material, the surface hardness cannot be increased, and a laminate such as a circularly polarizing plate is manufactured using the retardation layer having a small surface hardness. May be done. When a laminate is manufactured using a retardation layer having a low surface hardness, it has been found that scratches occur in the retardation layer during product processing such as transportation of the laminate. Such scratches are caused by deterioration of the optical characteristics of the laminated body including the retardation layer, for example, so-called light loss due to the retardation layer not exhibiting the phase difference in the scratched portion, or the position of the retardation layer in the scratched portion. It can cause discoloration of reflected light due to changes in phase difference.

The present invention provides an optical laminate having a retardation layer having a low maltensity hardness, an optical laminate that can be expected to suppress deterioration of optical characteristics, an optical laminate with a laminated layer, and a method for producing the same.

The present invention provides the following optical laminate, an optical laminate with a bonding layer, and a method for producing the same.
[1] An optical laminate having a polarizing plate having protective layers on one or both sides of a linearly polarized light layer, a first retardation layer, and a second retardation layer in this order.
The first retardation layer includes a first liquid crystal layer which is a cured product layer of a polymerizable liquid crystal compound.
The second retardation layer includes a second liquid crystal layer which is a cured product layer of a polymerizable liquid crystal compound.
The Martens hardness H1 of the second retardation layer at a pressurizing speed of 1 mN / 5s and a creep time of 5s is 10 N / mm ² or less.
The ratio (H2 / H1) of the Martens hardness H2 to the Martens hardness H1 at a pressurizing speed of 1 mN / 5s and a creep time of 5s on the second retardation layer side of the optical laminate is 15 or more. Optical laminate.
[2] An optical laminate having a polarizing plate having protective layers on one or both sides of a linearly polarized light layer, a first retardation layer, and a second retardation layer in this order.
The first retardation layer includes a first liquid crystal layer which is a cured product layer of a polymerizable liquid crystal compound.
The second retardation layer includes a second liquid crystal layer which is a cured product layer of a polymerizable liquid crystal compound.
The Martens hardness H1 of the second retardation layer at a pressurizing speed of 1 mN / 5s and a creep time of 5s is 10 N / mm ² or less.
An optical laminate in which the number of scratches on the second retardation layer side of the optical laminate by the scratch resistance test is 10/20 mm or less.
[3] The first retardation layer and the second retardation layer are bonded via a second bonding layer.
The optical laminate according to [1] or [2], wherein the second bonding layer is an adhesive curing layer.
[4] The optical laminate according to [3], wherein the adhesive cured layer constituting the second bonding layer is a cured layer of an active energy ray-curable adhesive.
[5] The polarizing plate and the first retardation layer are bonded via a first bonding layer.
The optical laminate according to any one of [1] to [4], wherein the first bonding layer is an adhesive curing layer or an adhesive layer.
[6] The optical laminate according to [5], wherein the first bonding layer is an adhesive cured layer, and the adhesive cured layer is a cured layer of an active energy ray-curable adhesive.
[7] The optical laminate according to any one of [1] to [6], wherein the first retardation layer is a laminate of the first liquid crystal layer and the first alignment layer.
[8] The second retardation layer is a laminate of the second liquid crystal layer and the second alignment layer.
The optical laminate according to any one of [1] to [7], wherein the second alignment layer is provided on the side of the second liquid crystal layer opposite to the first retardation layer side.
[9] An optical laminate with a laminating layer having the optical laminate according to any one of [1] to [8] and a third laminating layer.
The third bonding layer is an optical laminate with a bonding layer provided on the side of the second retardation layer opposite to the first retardation layer side.
[10] The bonding layer according to [9], which has a release film that can be peeled off from the third bonding layer on the side of the third bonding layer opposite to the second retardation layer side. With optical laminate.
[11] The method for manufacturing an optical laminate with a bonding layer according to [9] or [10].
A step of transporting the optical laminate while bringing the transport roll into contact with the second retardation layer side of the optical laminate.
A method for producing an optical laminate with a bonded layer, which comprises a step of forming the third bonded layer on the second retardation layer side of the optical laminated body after the transfer step.
[12] The method for producing an optical laminate with a bonding layer according to [11], further comprising a step of laminating a release film on the side of the third bonding layer opposite to the second retardation layer side. ..

According to the present invention, it is possible to provide an optical laminate, an optical laminate with a bonding layer, and a method for producing the same, which can be expected to suppress deterioration of optical characteristics.

It is schematic cross-sectional view which shows typically an example of the optical laminated body of this invention. It is schematic cross-sectional view which shows another example of the optical laminated body of this invention schematically. It is schematic cross-sectional view which shows typically an example of the optical laminated body with a laminating layer of this invention. It is the schematic cross-sectional view which shows typically another example of the optical laminated body with a laminating layer of this invention. It is the schematic cross-sectional view which shows typically an example of the manufacturing process of the optical laminate of this invention. It is schematic cross-sectional view which shows another example of the manufacturing process of the optical laminate of this invention schematically. It is the schematic which shows an example of the manufacturing process of the optical laminate with a laminating layer of this invention schematically. It is the schematic which shows typically another example of the manufacturing process of the optical laminate with a laminated layer of this invention.

Hereinafter, preferred embodiments of the optical laminate of the present invention, the optical laminate with a bonding layer, and a method for producing the same will be described with reference to the drawings.

(Optical laminate)
1 and 2 are schematic cross-sectional views schematically showing an example of the optical laminate of the present embodiment. As shown in FIGS. 1 and 2, the optical laminates 1a and 1b of the present embodiment (hereinafter, both are collectively referred to as “optical laminate 1”) are protected on one or both sides of the linearly polarizing layer. The polarizing plate 40 having a layer, the first retardation layer 10, and the second retardation layer 20 are provided in this order. The first retardation layer 10 includes a first liquid crystal layer 12 which is a cured product layer of a polymerizable liquid crystal compound. The second retardation layer 20 includes a second liquid crystal layer 22 which is a cured product layer of a polymerizable liquid crystal compound. The Martens hardness H1 (hereinafter, may be referred to as “Martens hardness H1 of the second retardation layer 20”) at a pressurizing speed of 1 mN / 5s and a creep time of 5s of the second retardation layer 20 is 10 N / mm ^2. It is as follows.

The optical laminate 1 satisfies at least one of the following [a] and [b].
[A] The Martens hardness H2 at a pressurizing speed of 1 mN / 5s and a creep time of 5s on the second retardation layer 20 side of the optical laminate 1 (hereinafter, may be referred to as “Martens hardness H2 of the optical laminate 1”. ) And the Martens hardness H1 (H2 / H1) is 15 or more.
[B] The number of scratches on the second retardation layer 20 side of the optical laminate 1 in the scratch resistance test is 10/20 mm or less.

In the optical laminate 1, the first retardation layer 10 may be the first liquid crystal layer 12 itself, which is a cured product layer of the polymerizable liquid crystal compound, and the first liquid crystal layer 12 and the first alignment layer 11 are laminated. It may be a body. In the optical laminate 1a shown in FIG. 1, the case where the first alignment layer 11 is provided on the polarizing plate 40 side of the first liquid crystal layer 12 is shown, but as in the optical laminate 1b shown in FIG. The alignment layer 11 may be provided on the second retardation layer 20 side of the first liquid crystal layer 12.

In the optical laminate 1, the second retardation layer 20 may be the second liquid crystal layer 22 itself, which is a cured product layer of the polymerizable liquid crystal compound, and the second liquid crystal layer 22 and the second alignment layer 21 are laminated. It may be a body. The second alignment layer 21 is usually provided on the side of the second liquid crystal layer 22 opposite to the first retardation layer 10 side.

The Martens hardness H1 of the second retardation layer 20 is 10 N / mm ² or less, may be 9 N / mm ² or less, may be 8 N / mm ² or less, and may be 7 N / mm ² or less. It may be 6 N / mm ² or less, and usually 1 N / mm ² or more. The Martens hardness H1 of the second retardation layer 20 is, for example, the type of the polymerizable liquid crystal compound constituting the second liquid crystal layer 22, the type of the polymerization initiator, the degree of curing (degree of polymerization) of the polymerizable liquid crystal compound, and the second. Depending on the thickness of the liquid crystal layer 22, the type of material constituting the second alignment layer 21, the degree of curing (polymerization) of the second alignment layer 21, the thickness of the second alignment layer 21, and the like when the second alignment layer 21 is included. Can be adjusted. The Martens hardness H1 of the second retardation layer 20 can be measured by the method described in Examples described later, and as described in Examples described later, the glass plate is passed through an adhesive layer. The measurement can be performed in a state where the second retardation layers are laminated.

Martens hardness H2 of the optical stack 1 may be, for example, with 10 N / mm ² or more, may also be 30 N / mm ² or more, may also be 50 N / mm ² or more, 80 N / mm ² or more may also be, may also be 100 N / mm ² or more, it may also be 120 N / mm ² or more, may also be 140 N / mm ² or more, usually 300N / mm ² or less. The degree of polymerization H2 of the optical laminate 1 constitutes, for example, the degree of polymerization H1 of the second retardation layer 20, the types of the first bonding layer 31 and the second bonding layer 32 described later, and the first liquid crystal layer 12. The type of the polymerizable liquid crystal compound to be polymerized, the type of the polymerization initiator, the degree of curing (degree of polymerization) of the polymerizable liquid crystal compound, the thickness of the first liquid crystal layer 12, and the first oriented layer 11 when the first oriented layer 11 is included. It can be adjusted by the type of the constituent material, the degree of curing (degree of polymerization) of the first alignment layer 11, the thickness of the first alignment layer 11, and the like. The Martens hardness H2 of the optical laminate 1 can be measured by the method described in Examples described later. As described in Examples described later, the optical laminate 1 is laminated on a glass plate via an adhesive layer. It can be measured in the state.

The ratio (H2 / H1) of the Martens hardness H2 of the optical laminate 1 to the Martens hardness H1 of the second retardation layer 20 is 15 or more, may be 20 or more, or may be 25 or more. It may be 30 or more, 50 or more, or 70 or more. When the ratio (H2 / H1) is in the above range, the Martens hardness H2 of the optical laminate 1 is sufficiently larger than the Martens hardness H1 of the second retardation layer 20. Therefore, the Martens hardness H1 of the second retardation layer 20 on the surface side of the optical laminate 1 is small, and the surface of the optical laminate 1 (the surface on the second retardation layer 20 side) is soft and easily deformed. However, it is considered that the optical laminate 1 is hard and hard to be deformed. Therefore, even if the surface of the optical laminate 1 is made of a material that is easily deformed and easily scratched by rubbing or the like, the optical laminate 1 is not easily deformed, so that the occurrence of scratches due to rubbing or the like can be suppressed. It is presumed. As a result, in the optical laminate 1, the optical characteristics are deteriorated due to the scratches generated in the second retardation layer 20, for example, light is lost due to the retardation layer not exhibiting the phase difference in the scratched portion, and the scratched portion is positioned. It can be expected that the discoloration of the reflected light due to the change in the phase difference of the phase difference layer can be suppressed.

The number of scratches on the second retardation layer 20 side of the optical laminate 1 in the scratch resistance test is 10 pieces / 20 mm or less, 8 pieces / 20 mm or less, or 5 pieces / 20 mm or less. Well, it may be 3 pieces / 20 mm or less. When the number of scratches in the scratch resistance test is within the above range, the optical laminate in which the above-mentioned deterioration of optical characteristics such as light loss and discoloration of reflected light due to the scratches in the second retardation layer 20 is suppressed is suppressed. It can be expected that 1 will be obtained. For the number of scratches in the scratch resistance test, for example, the ratio (H2 / H1) described in the above [a] is adjusted, the type of the first bonding layer 31 and the second bonding layer 32 described later is selected, and the like. Can be adjusted by. The number of scratches in the scratch resistance test can be measured by the method described in Examples described later. The unit of the number of scratches, "stripes / 20 mm", represents the number of scratches generated in a region having a width of 20 mm by the scratch resistance test.

In the optical laminate 1, the first bonding layer 31 for bonding the polarizing plate 40 and the first retardation layer 10 and the first retardation layer 10 and the second retardation layer 20 are bonded together. It is preferable to have a second bonding layer 32 for this purpose. The first bonding layer 31 and the second bonding layer 32 are independently an adhesive curing layer or an adhesive layer, and at least the second bonding layer 31 and the second bonding layer 32 are bonded. The laminated layer 32 is preferably an adhesive-cured layer, and more preferably both are adhesive-cured layers.

Since the second bonding layer 32 is an adhesive curing layer, the second bonding layer 32 can be formed to be harder and less likely to be deformed as compared with the case where the second bonding layer 32 is an adhesive layer. .. The second bonding layer 32 is a bonding layer for bonding the first retardation layer 10 and the second retardation layer 20, and can be provided in direct contact with the second retardation layer 20. As a result, even if the Martens hardness H1 of the second retardation layer 20 is small and the second retardation layer 20 is easily deformed, the second bonding layer 32 provided adjacent to the second retardation layer 20 can be formed. Since it is hard and hard to be deformed, it is possible to suppress the occurrence of scratches when the surface of the optical laminate 1 (the surface on the side of the second retardation layer) is rubbed.

When the second bonding layer 32 and the first bonding layer 31 are adhesive curing layers, the second bonding layer 32 is an adhesive curing layer and the first bonding layer 31 is an adhesive layer. In comparison, the Martens hardness H2 of the optical laminate 1 can be increased. As a result, the occurrence of scratches such as when the surface of the optical laminate 1 (the surface on the second retardation layer side) is rubbed can be further suppressed, so that the optical characteristics such as the above-mentioned light omission and discoloration of the reflected light are further deteriorated. It can be expected that a further suppressed optical laminate 1 can be obtained.

The adhesive curing layer constituting the first bonding layer 31 and the second bonding layer 32 is preferably a cured layer of an active energy ray-curable adhesive, and is preferably a cured layer of an ultraviolet curable adhesive. More preferable. The first bonding layer 31 and the second bonding layer 32 may be the same adhesive curing layer or different adhesive curing layers.

The optical laminate 1 may have a protective film provided on the side opposite to the first retardation layer 10 side of the polarizing plate 40 so as to be peelable from the polarizing plate 40. The protective film and the polarizing plate 40 can be bonded to each other due to the adhesiveness of the protective film. The optical laminate 1 may be a single-wafered body, or may be a long body having a length that is wound into a roll shape during storage, transportation, or the like.

The optical laminate 1 can be used as a circularly polarizing plate. When the optical laminate 1 is a circularly polarizing plate, for example, the first retardation layer 10 can be a 1/2 wavelength retardation layer, and the second retardation layer 20 can be a 1/4 wavelength retardation layer. Alternatively, one of the first retardation layer 10 and the second retardation layer 20 may be a 1/4 wavelength retardation layer having an inverse wavelength dispersion, and the other may be a positive C plate.

(Optical laminate with laminated layer)
3 and 4 are schematic cross-sectional views schematically showing an example of the optical laminate with a laminated layer of the present embodiment. The optical laminates 3a and 3b with a laminating layer of the present embodiment (hereinafter, both may be collectively referred to as "optical laminate 3 with a laminating layer") are the optical laminating body 1 and the third laminating layer 33. And have. The optical laminate 3a with a laminating layer shown in FIG. 3 is an optical laminating body 1a provided with a third laminating layer 33, and the optical laminating body 3b with a laminating layer shown in FIG. 4 is an optical laminated body 1b. A third bonded layer 33 is provided on the surface. As shown in FIGS. 3 and 4, the third bonding layer 33 is provided on the side opposite to the first retardation layer 10 side of the second retardation layer 20 of the optical laminate 1.

The third bonding layer 33 can be used for bonding the optical laminate 1 to the image display element. The third bonding layer 33 is an adhesive curing layer or an adhesive layer.

The optical laminate 3 with a bonding layer further has a release film 35 that can be peeled off from the third bonding layer 33 on the side of the third bonding layer 33 opposite to the second retardation layer 20 side. You may be. The release film 35 is preferably provided when the third bonding layer 33 is an adhesive layer.

The optical laminate 3 with a laminating layer may be a single-wafered body, or may be a long body having a length that is wound into a roll shape during storage, transportation, or the like.

Since the optical laminate 3 with a bonding layer is obtained by using the optical laminate 1, it is considered that the above-mentioned deterioration of optical characteristics such as light loss and discoloration of reflected light is suppressed.

(Manufacturing method of optical laminate (1))
FIG. 5 is a schematic cross-sectional view schematically showing an example of the manufacturing process of the optical laminate of the present embodiment. The method for manufacturing the optical laminate 1a shown in FIG. 1 is as shown in FIG.
Step of preparing the first retardation layer 18 with a base material layer in which the first retardation layer 10 is formed on the first base material layer 15 ((a) in FIG. 5).
Step of preparing the second retardation layer 28 with a base material layer in which the second retardation layer 20 is formed on the second base material layer 25 ((b) in FIG. 5).
The first retardation layer 10 side of the first retardation layer 18 with the base material layer and the second retardation layer 20 side of the second retardation layer 28 with the base material layer are connected via the second bonding layer 32. Laminating step ((c) in FIG. 5),
A step of peeling off the first base material layer 15 ((d) in FIG. 5) after the step of laminating via the second bonding layer 32.
A step of bonding the surface exposed by peeling the first base material layer 15 and the polarizing plate 40 via the first bonding layer 31 ((e) in FIG. 5), and
A step of peeling the second base material layer 25 after the step of laminating via the first laminating layer 31.
Can be included.

The first retardation layer 18 with a base material layer is for forming a liquid crystal layer containing a polymerizable liquid crystal compound on the first base material layer 15 without passing through the first alignment layer 11 or the first orientation layer 11. It can be obtained by applying and drying the composition and polymerizing and curing the polymerizable liquid crystal compound to form the first liquid crystal layer 12. FIG. 5 shows a case where the first retardation layer 18 is a laminate of the first alignment layer 11 and the first liquid crystal layer 12, but the first retardation layer 18 includes the first alignment layer 11. You don't have to.

The second retardation layer 28 with a base material layer is for forming a liquid crystal layer containing a polymerizable liquid crystal compound on the second base material layer 25, without passing through the second orientation layer 21 or the second orientation layer 21. It can be obtained by applying and drying the composition and polymerizing and curing the polymerizable liquid crystal compound to form the second liquid crystal layer 22. FIG. 5 shows a case where the second retardation layer 20 is a laminate of the second alignment layer 21 and the second liquid crystal layer 22, but the second retardation layer 20 includes the second alignment layer 21. You don't have to.

In the step of laminating via the second bonding layer 32, for example, first, the first retardation layer 10 side of the first retardation layer 18 with the base material layer and / or the second retardation layer 28 with the base material layer 28 A second bonding agent composition layer for forming the second bonding layer 32 is formed on the second retardation layer 20 side of the above. Next, after laminating the first retardation layer 18 with the base material layer and the second retardation layer 28 with the base material layer via the second binder composition layer, from the second binder composition layer. The second bonded layer 32 is formed. The method for forming the second bonding layer 32 from the second bonding agent composition layer may be selected according to the type of the second bonding agent composition layer. For example, when the adhesive contained in the second adhesive composition is an adhesive, the second adhesive layer 32 is formed by curing the adhesive by irradiating with active energy rays, heat treatment, or the like. It may be formed, and when the bonding agent contained in the second bonding agent composition is a pressure-sensitive adhesive, the second bonding agent composition layer may be the second bonding layer 32. As a result, the first base material layer 15, the first retardation layer 10 (first alignment layer 11, the first liquid crystal layer 12), the second bonding layer 32, and the second retardation layer 20 (second liquid crystal layer 22, A laminated body in which the second oriented layer 21) and the second base material layer 25 are laminated in this order is obtained ((c) in FIG. 5).

In the step of peeling the first base material layer 15, the first base material layer 15 is peeled off from the laminate shown in FIG. 5 (c). In the step of peeling the first base material layer 15, only the first base material layer 15 may be peeled off, and when the first base material layer 11 is present, the first base material layer 15 and the first orientation layer 11 are also peeled off. It may be peeled off. As a result, the first retardation layer 10 (first alignment layer 11, first liquid crystal layer 12), the second bonding layer 32, the second retardation layer 20 (second liquid crystal layer 22, second alignment layer 21), And a laminated body in which the second base material layer 25 is laminated in this order is obtained ((d) in FIG. 5).

In the step of laminating via the first laminating layer 31, for example, first, the exposed surface side of the laminate shown in FIG. 5 (d) exposed by peeling the first base material layer 15 and / or , A first laminating agent composition layer for forming the first laminating layer 31 is formed on the polarizing plate 40. Next, after laminating the laminate shown in FIG. 5D and the polarizing plate 40 via the first bonding agent composition layer, the first bonding layer 31 is transferred from the first bonding agent composition layer. Form. The method for forming the first bonding layer 31 from the first bonding agent composition layer may be selected according to the type of the first bonding agent composition layer, for example, from the second bonding agent composition layer to the first. 2 The method described in the method for forming the bonded layer 32 may be used. As a result, the polarizing plate 40, the first bonded layer 31, the first retardation layer 10 (first alignment layer 11, the first liquid crystal layer 12), the second bonding layer 32, and the second retardation layer 20 (second alignment layer 12). A laminated body in which the liquid crystal layer 22, the second alignment layer 21), and the second base material layer 25 are laminated in this order is obtained ((e) in FIG. 5).

In the step of peeling the second base material layer 25, the second base material layer 25 is peeled off from the laminate shown in FIG. 5 (e). In the step of peeling the second base material layer 25, only the second base material layer 25 may be peeled off, and if the second base material layer 21 is present, the second base material layer 25 and the second orientation layer 21 are also peeled off. It may be peeled off. As a result, the optical laminate 1a shown in FIG. 1 can be obtained.

One of the bonding surfaces of each layer to be bonded via the first bonding layer 31 and the second bonding layer 32 before forming the first bonding agent composition layer and the second bonding agent composition layer. Alternatively, both may be subjected to an easy adhesion treatment such as a saponification treatment, a corona discharge treatment, a plasma treatment, a flame treatment, a primer treatment, and an anchor coating treatment.

(Manufacturing method of optical laminate (2))
FIG. 6 is a schematic cross-sectional view schematically showing another example of the manufacturing process of the optical laminate of the present embodiment. The method for manufacturing the optical laminate 1b shown in FIG. 2 is as shown in FIGS. 5 and 6.
Step of preparing the first retardation layer 18 with a base material layer in which the first retardation layer 10 is formed on the first base material layer 15 ((a) in FIG. 5).
Step of preparing the second retardation layer 28 with a base material layer in which the second retardation layer 20 is formed on the second base material layer 25 ((b) in FIG. 5).
A step of laminating the first retardation layer 10 side of the first retardation layer 18 with a base material layer and the polarizing plate 40 via the first bonding layer 31 ((a) in FIG. 6).
A step of peeling off the first base material layer 15 ((b) in FIG. 6) after the step of laminating via the first bonding layer 31.
A step of bonding the surface exposed by peeling the first base material layer 15 and the second retardation layer 20 side of the second retardation layer 28 with the base material layer via the second bonding layer 32. ((C) in FIG. 6) and
A step of peeling the second base material layer 25 after the step of laminating via the second laminating layer 32.
Can be included.

Examples of the method for obtaining the first retardation layer 18 with a base material layer and the second retardation layer 28 with a base material layer include the above methods. FIG. 6 shows a case where the first retardation layer 18 is a laminate of the first alignment layer 11 and the first liquid crystal layer 12, but the first retardation layer 18 includes the first alignment layer 11. You don't have to. Similarly, FIG. 6 shows a case where the second retardation layer 20 is a laminated body of the second alignment layer 21 and the second liquid crystal layer 22, but the second retardation layer 20 is the second alignment layer 21. Does not have to be included.

In the step of laminating via the first bonding layer 31, for example, first, the first bonding layer is attached to the first retardation layer 10 side of the first retardation layer 18 with the base material layer and / or the polarizing plate 40. A first patch composition layer for forming 31 is formed. Next, after laminating the first retardation layer 18 with the base material layer and the polarizing plate 40 via the first bonding agent composition layer, the first bonding layer 31 is transferred from the first bonding agent composition layer. Form. Examples of the method for forming the first bonding layer 31 from the first bonding agent composition layer include the above-mentioned methods. As a result, a laminate in which the polarizing plate 40, the first bonding layer 31, the first retardation layer 10 (first liquid crystal layer 12, the first alignment layer 11), and the first base material layer 15 are laminated in this order is formed. It is obtained ((a) in FIG. 6).

In the step of peeling the first base material layer 15, the first base material layer 15 is peeled off from the laminate shown in FIG. 6A. In the step of peeling the first base material layer 15, only the first base material layer 15 may be peeled off, and when the first base material layer 11 is present, the first base material layer 15 and the first orientation layer 11 are also peeled off. It may be peeled off. As a result, a laminate in which the polarizing plate 40, the first bonding layer 31, and the first retardation layer 10 (first liquid crystal layer 12, first alignment layer 11) are laminated in this order can be obtained ((FIG. 6). b)).

In the step of laminating via the second laminating layer 32, for example, first, the exposed surface side of the laminate shown in FIG. 6 (b) exposed by peeling off the first base material layer 15 and / or On the side of the second retardation layer 20 of the second retardation layer 28 with the base material layer, a second bonding agent composition layer for forming the second bonding layer 32 is formed. Next, after laminating the laminate shown in FIG. 6 (b) and the second retardation layer 28 with the base material layer via the second patch composition layer, from the second patch composition layer. The second bonded layer 32 is formed. Examples of the method for forming the second bonding layer 32 from the second bonding agent composition layer include the above-mentioned methods. As a result, the polarizing plate 40, the first bonded layer 31, the first retardation layer 10 (first liquid crystal layer 12, the first alignment layer 11), the second bonding layer 32, and the second retardation layer 20 (second). A laminated body in which the liquid crystal layer 22, the second alignment layer 21), and the second base material layer 25 are laminated in this order is obtained ((c) in FIG. 6).

In the step of peeling the second base material layer 25, the second base material layer 25 is peeled off from the laminate shown in FIG. 6 (c). In the step of peeling the second base material layer 25, only the second base material layer 25 may be peeled off, and if the second base material layer 21 is present, the second base material layer 25 and the second orientation layer 21 are also peeled off. It may be peeled off. As a result, the optical laminate 1b shown in FIG. 2 can be obtained.

One of the bonding surfaces of each layer to be bonded via the first bonding layer 31 and the second bonding layer 32 before forming the first bonding agent composition layer and the second bonding agent composition layer. Alternatively, both may be subjected to an easy adhesion treatment such as a saponification treatment, a corona discharge treatment, a plasma treatment, a flame treatment, a primer treatment, and an anchor coating treatment.

(Manufacturing method of optical laminate with laminated layer)
7 and 8 are schematic views schematically showing an example of a manufacturing process of the optical laminate with a laminated layer of the present embodiment. In the figure, the arrows indicate the transport direction. 7 and 8 show a method of manufacturing an optical laminate 3 with a laminated layer of a long body by roll to roll, but the present invention is not limited to this. The method for manufacturing the optical laminate 3 with a bonding layer is as shown in FIGS. 7 and 8.
A step of transporting the optical laminate 1 while abutting the transport roll 51 on the second retardation layer 20 side of the optical laminate 1 (FIGS. 1 and 2).
A step of forming a third bonding layer 33 on the second retardation layer 20 side of the optical laminate 1 is included after the step of transporting.

The method for producing the optical laminate with the bonding layer may further include a step of laminating the release film 35 on the side of the third bonding layer 33 opposite to the second retardation layer 20 side.

In the step of transporting the optical laminate 1, the long optical laminate 1 is unwound, and the optical laminate 1 is transported while the transport roll 51 is in contact with the second retardation layer 20 side of the optical laminate 1. The number of transport rolls 51 that abut on the second retardation layer side of the optical laminate 1 may be one or two or more. It may have one or more transport rolls that come into contact with the polarizing plate 40 side of the optical laminate 1. The transport roll 51 may be a drive roll having a drive source or a guide roll having no drive source.

In the step of forming the third bonded layer 33, the third bonded layer 33 is formed on the second retardation layer 20 side of the optical laminate 1 in contact with the transport roll 51. As a method of forming the third bonding layer 33, as shown in FIG. 7, a third bonding agent composition for forming the third bonding layer 33 is applied using the coating device 52 to form a third bonding layer 33. A method for forming a bonding agent composition layer, as shown in FIG. 8, a bonding with a release film in which a third bonding layer 33 is formed on a release film 35 on the second retardation layer 20 side of the optical laminate 1. Examples thereof include a method of laminating the third bonding layer 33 side of the bonding layer 36.

As shown in FIG. 7, when the third patch composition is applied to the optical laminate 1, the extrusion method, the gravure coating method, the die coating method, the wire bar coating method, the doctor blade coating method, the applicator method, etc. A known coating method such as a coating method of the above, a printing method such as a flexographic method, or the like can be used.

As shown in FIG. 8, when the optical laminate 1 and the bonding layer 36 with a release film are laminated, they may be pressed from above and below using a bonding roll 53 or the like arranged at the laminated position.

As described above, the surface of the optical laminate 1 on the second retardation layer 20 side can suppress scratches generated when rubbed or the like. Therefore, even when the optical laminate 1 is conveyed while the conveying roll 51 is in contact with the second retardation layer 20 side of the optical laminate 1, the surface of the optical laminate 1 on the second retardation layer 20 side is scratched. It can be suppressed from occurring. As a result, the optical laminate 3 with a bonding layer having the third bonding layer 33 formed on the side of the second retardation layer 20 in contact with the transport roll 51 has optics such as light loss due to the above-mentioned scratches and discoloration of reflected light. It is considered that the deterioration of the characteristics is suppressed.

In the optical laminate 1, a polarizing plate 40 is provided on one surface side of the first retardation layer 10, and a second retardation layer 20 is provided on the other surface side of the first retardation layer 10. The surface of the first retardation layer 10 is not exposed. Therefore, when the optical laminate 3 with the bonding layer is manufactured using the optical stack 1, the first retardation layer 10 does not come into direct contact with the conveying roll, the bonding roll, or the like. Therefore, in the method for manufacturing the optical laminate 3 with a bonding layer, the first retardation layer 10 is less likely to be scratched.

Hereinafter, the optical laminate of the present embodiment, the optical laminate with a bonding layer, and the details of each member used in these manufacturing methods will be described.

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

Examples of the linearly polarizing layer containing the PVA-based resin film include a polyvinyl alcohol (hereinafter, may be abbreviated as "PVA") -based film, a partially formalized PVA-based film, and an ethylene / vinyl acetate copolymer system partially saponified film. Examples thereof include those obtained by subjecting a hydrophilic polymer film such as, etc. to a dyeing treatment with a bicolor substance such as iodine or a bicolor dye, and a stretching treatment. Since it is excellent in optical characteristics, it is preferable to use a linearly polarizing layer obtained by dyeing a PVA-based resin film with iodine and uniaxially stretching it.

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

The saponification degree of the polyvinyl alcohol-based resin is usually about 85 to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol-based resin may be modified, and for example, polyvinyl formal or polyvinyl acetal modified with aldehydes can also be used. The average degree of polymerization of the polyvinyl alcohol-based resin is usually about 1,000 to 10,000, preferably about 1,500 to 5,000. The average degree of polymerization of the polyvinyl alcohol-based resin can be determined in accordance with JIS K 6726 (1994). If the average degree of polymerization is less than 1000, it is difficult to obtain preferable polarization performance, and if it exceeds 10,000, the film processability may be inferior.

A film formed of such a polyvinyl alcohol-based resin is used as a raw film for a linearly polarizing layer. The method for forming the film of the polyvinyl alcohol-based resin is not particularly limited, and the film can be formed by a known method. The film thickness of the polyvinyl alcohol-based resin raw film is, for example, about 10 to 100 μm, preferably about 10 to 60 μm, and more preferably about 15 to 30 μm.

As another method for producing a linear polarizing layer containing a PVA-based resin film, first prepare a base film, apply a resin solution such as a polyvinyl alcohol-based resin on the base film, and dry the base film to remove the solvent. Examples thereof include a step of forming a resin layer on the base film. A primer layer can be formed in advance on the surface of the base film on which the resin layer is formed. As the base film, a resin film such as PET can be used. Examples of the material of the primer layer include a resin obtained by cross-linking a hydrophilic resin used for the linearly polarizing layer.

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

The uniaxial stretching of the base film and the resin layer may be performed before dyeing, during dyeing, or during boric acid treatment after dyeing, and each of these multiple steps is uniaxial. Stretching may be performed. The base film and the resin layer may be uniaxially stretched in the MD direction (film transport direction), in this case, uniaxially stretched between rolls having different peripheral speeds, or uniaxially stretched using a thermal roll. You may. Further, the base film and the resin layer may be uniaxially stretched in the TD direction (direction perpendicular to the film transport direction), and in this case, the so-called tenter method can be used. Further, the stretching of the base film and the resin layer may be a dry stretching in which the resin layer is stretched in the air, or a wet stretching in which the resin layer is swollen with a solvent. In order to exhibit the performance of the linearly polarized light layer, the draw ratio is 4 times or more, preferably 5 times or more, and particularly preferably 5.5 times or more. There is no particular upper limit to the draw ratio, but it is preferably 8 times or less from the viewpoint of suppressing breakage and the like.

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

As a method for producing a linearly polarizing layer, which is a cured film obtained by orienting a dichroic dye on a polymerizable liquid crystal compound and polymerizing the polymerizable liquid crystal compound, the polymerizable liquid crystal compound and the dichroic dye are placed on a base film. Examples thereof include a method of applying the composition for forming a polarizing layer containing the mixture, polymerizing and curing the polymerizable liquid crystal compound while maintaining the liquid crystal state, and forming a linear polarizing layer. The linearly polarizing layer thus obtained is in a state of being laminated on the base film, and the linearly polarizing layer with the base film may be used as a polarizing plate to be described later.

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

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

The thickness of the linearly polarizing layer is preferably 2 μm or more, and more preferably 3 μm or more. The thickness of the linearly polarizing layer is 25 μm or less, preferably 15 μm or less, more preferably 13 μm or less, and further preferably 7 μm or less. The above-mentioned upper limit value and lower limit value can be arbitrarily combined.

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

The film formed of the thermoplastic resin may be surface-treated (for example, corona-treated) in order to improve the adhesion to the linearly polarizing layer made of the PVA-based resin and the dichroic substance, and may be subjected to a primer. A thin layer such as a layer (also referred to as an undercoat layer) may be formed.

The protective layer, the temperature 40 ° C., it is preferred that the moisture permeability of a humidity 90% RH is 1~1500g ^/ m 2 · 24hr. Temperature 40 ° C. of the protective layer, the moisture permeability of a humidity 90% RH is more preferably less 1000g ^/ m 2 · 24hr, more preferably at most ^{100g / m 2 · 24hr, 10g} / m 2 · It is more preferably 24 hr or less. Moisture permeability can be measured in accordance with JIS Z 0208: 1976.

When the protective layers are laminated on both sides of the linearly polarizing layer, the moisture permeability of the outer protective layer laminated on the visible side when the optical laminate is bonded to the optical display element and the moisture permeability of the outer protective layer and the first bonded layer side. It is preferable that the moisture permeability of the inner protective layer laminated on the inner protective layer is the same as that of the inner protective layer, or that the outer protective layer is smaller than the inner protective layer.

The protective layer may be, for example, a stretched one of the above-mentioned thermoplastic resin or a non-stretched one (hereinafter, may be referred to as “unstretched resin”). Examples of the stretching treatment include uniaxial stretching and biaxial stretching.

The stretching direction in the stretching treatment may be the length direction of the unstretched resin, the direction orthogonal to the length direction, or the direction obliquely intersecting with the length direction. In the case of uniaxial stretching, the unstretched resin may be stretched in any of these directions. The biaxial stretching may be simultaneous biaxial stretching in which two of these directions are simultaneously stretched, or sequential biaxial stretching in which stretching is performed in a predetermined direction and then in the other direction.

The stretching treatment is performed, for example, by using two or more pairs of nip rolls having an increased peripheral speed on the downstream side to stretch in the length direction, or by grasping both ends of the unstretched resin with a chuck and orthogonal to the length direction. This can be done by stretching in the direction or the like. At this time, it is possible to control the desired retardation value and wavelength dispersion by adjusting the thickness of the thermoplastic resin after stretching and adjusting the stretching ratio.

The thickness of the protective layer is preferably 3 μm or more, and more preferably 5 μm or more. The thickness of the protective layer is preferably 50 μm or less, more preferably 30 μm or less. The above-mentioned upper limit value and lower limit value can be arbitrarily combined.

(Protect film)
The protective film is a film for covering and protecting the surface of the polarizing plate, and is provided so as to be peelable from the polarizing plate. The protective film may be a resin film for a protective film having an adhesive layer formed therein, or may be formed of a self-adhesive film. The thickness of the protective film can be, for example, 30 to 200 μm, preferably 30 to 150 μm, and more preferably 30 to 120 μm.

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

As the pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive layer for a protective film, the same pressure-sensitive adhesive composition as the pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive layer described later can be used. Further, the protective film can be obtained by forming an adhesive layer on the surface of the resin film for a protective film by applying an adhesive composition, drying, or the like. If necessary, a surface treatment (for example, corona treatment) may be applied to the coated surface of the pressure-sensitive adhesive composition of the resin film for a protective film in order to improve adhesion, and a primer layer (undercoat layer) may be applied. A thin layer such as (also referred to as) may be formed. Further, if necessary, a release layer for covering and protecting the surface of the adhesive layer for the protective film on the side opposite to the resin film side for the protective film may be provided. This peeling layer can be peeled off at an appropriate timing when it is attached to the polarizing plate.

The self-adhesive film is a film capable of adhering by itself and maintaining the adhering state without providing a means for adhering a pressure-sensitive adhesive layer or the like. The self-adhesive film can be formed by using, for example, a polypropylene-based resin, a polyethylene-based resin, or the like.

(1st retardation layer and 2nd retardation layer)
The first retardation layer may be a first liquid crystal layer which is a cured product layer of a polymerizable liquid crystal compound, or may be a laminate of a first liquid crystal layer and a first alignment layer. Similarly, the second retardation layer may be a second liquid crystal layer which is a cured product layer of a polymerizable liquid crystal compound, or may be a laminate of a second liquid crystal layer and a second orientation layer. The second retardation layer has the Martens hardness H1 described above. The Martens hardness of the first retardation layer is not particularly limited, and may be the same as or different from the Martens hardness H1.

The first retardation layer and the second retardation layer (hereinafter, both may be collectively referred to as "phase difference layer") have a retardation characteristic as a whole, and this retardation characteristic is mainly polymerized. It can be adjusted according to the orientation state of the sex liquid crystal compound. Examples of the retardation layer include a positive A layer such as a layer giving a phase difference of λ / 4 and a layer giving a phase difference of λ / 2; and a positive C layer showing vertical orientation.

［式中、
ＡＬは、位相差層を構成する配向層を構成する樹脂を構成する重合性化合物に由来する構成単位の種類数を示す。なお、位相差層が液晶層のみから構成されている場合には、ＡＬ＝０である。
Ｃｗｉは、配向層を構成する樹脂における重合性化合物に由来する全構成単位を基準として、重合性化合物ｉに由来する構成単位の含有量（質量％）を示し、
Ｍｉは、配向層を構成する重合性化合物ｉの分子量を示し、
Ｎｉは、配向層を構成する重合性化合物ｉが有する重合性基の数を示す。
ＬＣは、液晶層が重合性液晶化合物の硬化物層である場合に、液晶層を構成する重合性液晶化合物に由来する構成単位の種類数を示す。
Ｃｗｊは、液晶層における重合性液晶化合物に由来する全構成単位を基準として、重合性液晶化合物ｊに由来する構成単位の含有量（質量％）を示し、
Ｍｊは、液晶層を構成する重合性液晶化合物ｊの分子量を示し、
Ｎｊは、液晶層を構成する重合性液晶化合物ｉが有する重合性基の数を示す。
Ｌ_ＡＬは、配向層の厚み［μｍ］を示し、
Ｌ_ＬＣは、液晶層の厚さ［μｍ］を示す。
Ｌ_{ｔｏｔａｌ}は、Ｌ_ＡＬとＬ_ＬＣとの和を示す。］ The retardation layer preferably has a polymerizable group amount N represented by the following formula (A) of 0.67 or less, more preferably 0.64 or less. The polymerizable group amount N is usually 0.01 or more, preferably 0.03 or more.

[During the ceremony,
AL indicates the number of types of structural units derived from the polymerizable compound that constitutes the resin that constitutes the alignment layer that constitutes the retardation layer. When the retardation layer is composed of only the liquid crystal layer, AL = 0.
Cwi indicates the content (mass%) of the structural units derived from the polymerizable compound i, based on all the structural units derived from the polymerizable compound in the resin constituting the alignment layer.
Mi indicates the molecular weight of the polymerizable compound i constituting the alignment layer.
Ni indicates the number of polymerizable groups contained in the polymerizable compound i constituting the alignment layer.
LC indicates the number of types of structural units derived from the polymerizable liquid crystal compound constituting the liquid crystal layer when the liquid crystal layer is a cured product layer of the polymerizable liquid crystal compound.
Cwj indicates the content (mass%) of the structural units derived from the polymerizable liquid crystal compound j based on all the structural units derived from the polymerizable liquid crystal compound in the liquid crystal layer.
Mj indicates the molecular weight of the polymerizable liquid crystal compound j constituting the liquid crystal layer.
Nj indicates the number of polymerizable groups contained in the polymerizable liquid crystal compound i constituting the liquid crystal layer.
_LAL indicates the thickness [μm] of the alignment layer.
_LLC indicates the thickness [μm] of the liquid crystal layer.
L _total indicates the sum of L _AL and _LLC. ]

(1st liquid crystal layer and 2nd liquid crystal layer)
The first liquid crystal layer and the second liquid crystal layer (hereinafter, both may be collectively referred to as "liquid crystal layer") are cured product layers formed by polymerizing a polymerizable liquid crystal compound. In the present specification, the optical axis of the polymerizable liquid crystal compound is horizontally oriented with respect to the base material layer plane, and the optical axis of the polymerizable liquid crystal compound is oriented perpendicular to the base material layer plane. Defined as vertical orientation. The optical axis means the direction in which the cross section cut out in the direction orthogonal to the optical axis becomes a circle in the refractive index ellipsoid formed by the orientation of the polymerizable liquid crystal compound, that is, the direction in which the refractive indexes in the two directions are equal. .. The first liquid crystal layer and the second liquid crystal layer may be a cured product layer formed by polymerizing the same polymerizable liquid crystal compound, or may be a cured product layer formed by polymerizing different polymerizable liquid crystal compounds. You may.

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

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

The polymerizable liquid crystal compound is a compound having at least one polymerizable group and having liquid crystallinity. When two or more kinds of polymerizable liquid crystal compounds are used in combination, it is preferable that at least one kind has two or more polymerizable groups in the molecule. The polymerizable group means a group involved in the polymerization reaction, and is preferably a photopolymerizable group. Here, the photopolymerizable group refers to a group that can participate in the polymerization reaction by an active radical, an acid, or the like generated from a photopolymerization initiator described later. Examples of the polymerizable group include a vinyl group, a vinyloxy group, a 1-chlorovinyl group, an isopropenyl group, a 4-vinylphenyl group, an acryloyloxy group, a methacryloyloxy group, an oxylanyl group, an oxetanyl group, a styryl group and an allyl group. Be done. Of these, an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxylanyl group and an oxetanyl group are preferable, and an acryloyloxy group is more preferable. The liquid crystal property of the polymerizable liquid crystal compound may be a thermotropic liquid crystal or a lyotropic liquid crystal, and when the thermotropic liquid crystal is classified by order, it may be a nematic liquid crystal or a smectic liquid crystal.

The liquid crystal layer may have a one-layer structure or a multi-layer structure having two or more layers. When having a multi-layer structure of two or more layers, when preparing the first retardation layer with a base material layer and the second retardation layer with a base material layer, which will be described later, the multi-layer structure of two or more layers is provided on the base material layer. The liquid crystal layer may be formed. The thickness of the liquid crystal layer is preferably 0.5 μm or more, may be 1 μm or more, is usually 10 μm or less, and may be 5 μm or less. The above upper limit value and lower limit value can be arbitrarily combined. When the thickness of the liquid crystal layer is 0.5 μm or more, sufficient durability can be easily obtained. When the thickness of the liquid crystal layer is 10 μm or less, it is possible to contribute to the thinning of the optical laminate.

(1st oriented layer and 2nd oriented layer)
The first alignment layer and the second alignment layer (hereinafter, both may be collectively referred to as "alignment layer") are liquid crystals contained in the first liquid crystal layer and the second liquid crystal layer formed on these alignment layers. It has an orientation regulating force that orients the compound in a desired direction. The oriented layer may be a vertically oriented layer in which the molecular axis of the polymerizable liquid crystal compound is vertically oriented with respect to the base material layer, or a horizontally oriented layer in which the molecular axis of the polymerizable liquid crystal compound is horizontally oriented with respect to the base material layer. It may be an inclined orientation layer in which the molecular axis of the polymerizable liquid crystal compound is inclined or oriented with respect to the base material layer. The first oriented layer and the second oriented layer may be the same oriented layer or may be different oriented layers.

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

For the oriented polymer layer, a composition in which the oriented polymer is dissolved in a solvent is applied to a base material layer (first base material layer or second base material layer) to remove the solvent, and if necessary, rubbing treatment is performed. Can be formed. In this case, the orientation regulating force can be arbitrarily adjusted in the orientation polymer layer formed of the orientation polymer depending on the surface condition of the orientation polymer and the rubbing conditions.

In the photo-oriented polymer layer, a composition containing a polymer or monomer having a photoreactive group and a solvent is applied to a base material layer (first base material layer or second base material layer) and irradiated with light such as ultraviolet rays. It can be formed by doing. In particular, when the orientation regulating force is exhibited in the horizontal direction, it can be formed by irradiating polarized light. In this case, in the photo-alignment polymer layer, the orientation-regulating force can be arbitrarily adjusted depending on the polarization irradiation conditions for the photo-orientation polymer.

The grub alignment layer is active on a plate-shaped master having grooves on the surface, for example, a method of forming a concavo-convex pattern by exposure, development, etc. through an exposure mask having a pattern-shaped slit on the surface of a photosensitive polyimide film. A method of forming an uncured layer of an energy ray-curable resin, transferring this layer to a base material layer (first base material layer or second base material layer), and curing the base material layer (first base material layer). Alternatively, an uncured layer of the active energy ray-curable resin is formed on the second base material layer), and the layer is formed by a method of forming irregularities and curing by pressing a roll-shaped master with irregularities against this layer. can do.

Examples of the resin used for forming the alignment layer include a resin obtained by polymerizing a polymerizable compound. The polymerizable compound is a compound having a polymerizable group, and is usually a non-liquid crystalline non-liquid crystal compound that does not become a liquid crystal state. The polymerizable groups of the polymerizable compound react with each other to polymerize the polymerizable compound, thereby forming a resin. Such a resin can be used as an alignment layer for orienting a polymerizable liquid crystal compound at the stage of forming the liquid crystal layer, and if it is not included in the retardation layer, it can be used as a material for a known alignment layer. The resin to be used is not particularly limited, and a cured product obtained by curing a known monofunctional or polyfunctional (meth) acrylate-based monomer under a polymerization initiator can be used.

Specifically, examples of the (meth) acrylate-based monomer include 2-ethylhexyl acrylate, cyclohexyl acrylate, diethylene glycol mono2-ethylhexyl ether acrylate, diethylene glycol monophenyl ether acrylate, tetraethylene glycol monophenyl ether acrylate, and trimethyl propantri. Acrylate, lauryl acrylate, lauryl methacrylate, isobornyl acrylate, isobornyl methacrylate, 2-phenoxyethyl acrylate, tetrahydrofurfuryl acrylate, 2-hydroxypropyl acrylate, benzyl acrylate, tetrahydrofurfuryl methacrylate, 2-hydroxyethyl methacrylate, benzyl Examples thereof include methacrylate, cyclohexyl methacrylate, methacrylic acid, and urethane acrylate. The resin may be one of these or a mixture of two or more. Such an oriented layer can be peeled off together with the base material layer before and after the step of forming the liquid crystal layer and then laminating it with a polarizing plate or another retardation layer.

The oriented layer may be included in the retardation layer in order to improve the peelability with respect to the base material layer and impart film strength to the retardation layer. When the retardation layer contains an alignment layer, the resin used for the alignment layer may be a cured product obtained by curing a monofunctional or bifunctional (meth) acrylate-based monomer, an imide-based monomer, or a vinyl ether-based monomer. preferable.

Examples of the monofunctional (meth) acrylate-based monomer include alkyl (meth) acrylates having 4 to 16 carbon atoms, βcarboxyalkyl (meth) acrylates having 2 to 14 carbon atoms, and alkylated phenyl (meth) having 2 to 14 carbon atoms. Examples thereof include acrylates, methoxypolyethylene glycol (meth) acrylates, phenoxypolyethylene glycol (meth) acrylates and isobonyl (meth) acrylates.

Examples of the bifunctional (meth) acrylate-based monomer include 1,3-butanediol di (meth) acrylate; 1,3-butanediol (meth) acrylate; 1,6-hexanediol di (meth) acrylate; ethylene glycol di. (Meta) acrylate; Diethylene glycol di (meth) acrylate; Neopentyl glycol di (meth) acrylate; Triethylene glycol di (meth) acrylate; Tetraethylene glycol di (meth) acrylate; Polyethylene glycol diacrylate; Bisphenol A bis (acrylate) Loyloxyethyl) ether; ethoxylated bisphenol A di (meth) acrylate; propoxylated neopentyl glycol di (meth) acrylate; ethoxylated neopentyl glycol di (meth) acrylate, 3-methylpentanediol di (meth) acrylate, etc. Can be mentioned.

Examples of the imide-based resin obtained by curing the imide-based monomer include polyamide and polyimide. The imide resin may be one of these or a mixture of two or more.

The resin forming the alignment layer may contain a monomer other than the monofunctional or bifunctional (meth) acrylate-based monomer, the imide-based monomer, and the vinyl ether-based monomer, but the monofunctional or bifunctional (meth) acrylate may be contained. The content ratio of the system monomer, the imide-based monomer, and the vinyl ether-based monomer may be 50% by weight or more, preferably 55% by weight or more, and more preferably 60% by weight or more in the total monomer. ..

The first oriented layer and the second oriented layer may be the same type of layer or different types of layers. When the oriented layer is included in the retardation layer, the thickness of the oriented layer is usually in the range of 10 nm to 10000 nm. When the orientation of the liquid crystal layer is horizontal with respect to the base material layer, the thickness of the alignment layer is preferably 10 nm to 1000 nm, and when the orientation of the liquid crystal layer is vertical with respect to the base material layer. The thickness of the alignment layer is preferably 100 nm to 10000 nm. When the thickness of the alignment layer is within the above range, the peelability to the base material layer can be improved and the film strength can be imparted to the retardation layer.

(Phase difference layer with base material layer)
The first retardation layer with a base material layer and the second retardation layer with a base material layer (hereinafter, both may be collectively referred to as "phase difference layer with a base material layer") are polymerized on the base material layer. It can be obtained by applying a composition for forming a liquid crystal layer containing a liquid crystal compound, drying the composition, and polymerizing the polymerizable liquid crystal compound to form a phase difference including a liquid crystal layer which is a cured product layer. The composition for forming a liquid crystal layer may be applied on the alignment layer when the alignment layer described later is formed on the base material layer, and when the liquid crystal layer has a multilayer structure of two or more layers, the liquid crystal is liquid crystal. A multi-layer structure may be formed by sequentially applying the layer-forming composition or the like.

The liquid crystal layer forming composition usually contains a solvent in addition to the polymerizable liquid crystal compound. As the solvent, an organic solvent is preferable, and for example, amide (eg, N, N-dimethylformamide), sulfoxide (eg, dimethyl sulfoxide), heterocyclic compound (eg, pyridine), hydrocarbon (eg, benzene, hexane), Alkyl halides (eg, chloroform, dichloromethane), esters (eg, methyl acetate, ethyl acetate, butyl acetate), ketones (eg, acetone, methyl ethyl ketone), ethers (eg, tetrahydrofuran, 1,2-dimethoxyethane) can be mentioned. Among them, alkyl halides and ketones are preferable. Further, two or more kinds of organic solvents may be used in combination.

The liquid crystal layer forming composition may further contain additives such as a polymerization initiator, a reactive additive, and a polymerization inhibitor. As these additives and the like, those exemplified in JP-A-2015-163937, JP-A-2016-42185, International Publication No. 2016/158940, and JP-A-2016-224128 can be used. ..

The composition for forming a liquid crystal layer may contain a polymerizable monomer, a surfactant and the like from the viewpoint of the uniformity of the coating film and the strength of the film. Examples of the polymerizable monomer include radically polymerizable or cationically polymerizable compounds. Among them, a polyfunctional radically polymerizable monomer is preferable. The polymerizable monomer is preferably one that can be copolymerized with the above-mentioned polymerizable liquid crystal compound. The amount of the polymerizable monomer used is preferably 1 to 50% by mass, more preferably 2 to 30% by mass, based on the total mass of the polymerizable liquid crystal compound. Examples of the surfactant include known compounds, but fluorine-based compounds are preferable.

The composition for forming a liquid crystal layer includes a vertical alignment accelerator such as a polarizing plate interface side vertical alignment agent and an air interface side vertical alignment agent, and horizontal alignment such as a polarizer interface side horizontal alignment agent and an air interface side horizontal alignment agent. Various alignment agents such as accelerators may be included. Further, the composition for forming a liquid crystal layer may contain an adhesion improver, a plasticizer, a polymer and the like in addition to the above components.

The composition for forming a liquid crystal layer is applied, for example, by a coating method such as a spin coating method, an extrusion method, a gravure coating method, a die coating method, a slit coating method, a bar coating method, an applicator method, or printing by a flexographic method or the like. It can be carried out by a known method such as a law. After applying the liquid crystal layer forming composition, it is preferable to remove the solvent under the condition that the polymerizable liquid crystal compound contained in the coating layer does not polymerize. Examples of the drying method include a natural drying method, a ventilation drying method, a heat drying method, and a vacuum drying method.

The polymerization of the polymerizable liquid crystal compound after the coating layer is dried can be carried out by a known method of polymerizing a compound having a polymerizable functional group. Examples of the polymerization method include thermal polymerization and photopolymerization, and photopolymerization is preferable from the viewpoint of easiness of polymerization. When a polymerizable liquid crystal compound is polymerized by photopolymerization, a composition containing a photopolymerization initiator is used as the liquid crystal layer forming composition, and this liquid crystal layer forming composition is applied, dried, and put into a dry film after drying. It is preferable that the contained polymerizable liquid crystal compound is liquid crystal oriented and photopolymerization is performed while maintaining this liquid crystal oriented state. Examples of the photopolymerization initiator include α-carbonyl compounds, acyloin ethers, α-hydrocarbon-substituted aromatic acyloin compounds, polynuclear quinone compounds, and combinations of triarylimidazole dimers and p-aminophenyl ketones. The amount of the polymerization initiator used is preferably 0.01 to 20% by mass, more preferably 0.5 to 5% by mass, based on the total solid content in the liquid crystal layer forming composition. ..

Photopolymerization can be performed by irradiating the liquid crystal-oriented polymerizable liquid crystal compound in the dry film with active energy rays. The active energy ray to be irradiated can be appropriately selected depending on the type and amount of the polymerizable group contained in the polymerizable liquid crystal compound, the type of the photopolymerization initiator, and the like. For example, visible light, ultraviolet rays, and laser light. , X-rays, α-rays, β-rays and γ-rays, and one or more types of active energy rays selected from the group. Of these, ultraviolet rays are preferable because the progress of the polymerization reaction can be easily controlled and those widely used in the art can be used as the photopolymerization apparatus, so that the polymerizable liquid crystal compound can be photopolymerized by the ultraviolet rays. And the type of photopolymerization initiator is preferably selected. In photopolymerization, the polymerization temperature can be controlled by irradiating the dry film with active energy rays while cooling it by an appropriate cooling means.

Examples of the light source of the active energy ray 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 carbon arc lamp, a tungsten lamp, a gallium lamp, an excima laser, and a wavelength range of 380. Examples thereof include an LED light source that emits light of up to 440 nm, a chemical lamp, a black light lamp, a microwave-excited mercury lamp, and a metal halide lamp.

The irradiation intensity of ultraviolet radiation is typically the case of ultraviolet B wave (wavelength region ^{280～310Nm),} a ^{100mW / cm 2 ~3,000mW / cm 2} . The ultraviolet irradiation intensity is preferably an intensity in a wavelength region effective for activating the cationic polymerization initiator or the radical polymerization initiator. The time for irradiating with ultraviolet rays is usually 0.1 seconds to 10 minutes, preferably 0.1 seconds to 5 minutes, more preferably 0.1 seconds to 3 minutes, and even more preferably 0.1 seconds. ~ 1 minute.

Ultraviolet rays can be irradiated once or in a plurality of times. Depending on the polymerization initiator used, the accumulated amount of light at a wavelength of 365nm is preferably in a 700 mJ / cm ² or more, more preferably, to 1,100mJ / cm ² or more, 1,300mJ / cm ² or more and It is more preferable to do so. The integrated light intensity is advantageous for increasing the polymerization rate of the polymerizable liquid crystal compound constituting the liquid crystal layer and improving the heat resistance. Integrated light intensity at a wavelength of 365nm is preferably in a 2,000 mJ / cm ² or less, and more preferably to 1,800mJ / cm ² or less. The integrated light intensity is preferable because it can suppress the coloring of the liquid crystal layer. Further, a cooling step may be provided after irradiation with ultraviolet rays. The cooling temperature can be, for example, 20 ° C. or lower, and can be 10 ° C. or lower. The cooling time can be, for example, 10 seconds or more, and 20 seconds or more.

(Base layer)
The first base material layer and the second base material layer (hereinafter, both may be collectively referred to as "base material layer") are the first orientation layer and the second base material layer to be described later, which are formed on these base material layers. It has a function as an alignment layer and a support layer for supporting the first liquid crystal layer and the second liquid crystal layer. The base material layer is preferably a film formed of a resin material.

As the resin material, for example, a resin material having excellent transparency, mechanical strength, thermal stability, stretchability and the like is used. Specifically, polyolefin resins such as polyethylene and polypropylene; cyclic polyolefin resins such as norbornene polymers; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; (meth) acrylic acid, poly (meth) methyl acrylate and the like. (Meta) acrylic acid resin; cellulose ester resin such as triacetyl cellulose, diacetyl cellulose, cellulose acetate propionate; vinyl alcohol resin such as polyvinyl alcohol and polyvinyl acetate; polycarbonate resin; polystyrene resin; poly Arilate-based resin; Polysulfone-based resin; Polyethersulfone-based resin; Polyamide-based resin; Polygon-based resin; Polyamideimide-based resin; Polyetherketone-based resin; Polyphenylene sulfide-based resin; Polyphenylene oxide-based resin; Polyvinyl chloride-based resin; Acrylonitrile -Butadiene-styrene resin; acrylonitrile / styrene resin; polyvinylidene chloride resin; polyacetal resin; modified polyphenylene ether resin; and mixtures, copolymers and the like thereof can be mentioned. Among these resins, it is preferable to use any one of cyclic polyolefin-based resin, polyester-based resin, cellulose ester-based resin, and (meth) acrylic acid-based resin, or a mixture thereof.

The base material layer may be a single layer obtained by mixing one type or two or more types of resin, or may have a multilayer structure of two or more layers. When having a multi-layer structure, the resins forming each layer may be the same or different from each other, or may be a coated / cured product layer such as a hard coat layer.

Any additive may be added to the resin material forming the film formed of the resin material. Examples of the additive include an ultraviolet absorber, an antioxidant, a lubricant, a plasticizer, a mold release agent, a colorant, a flame retardant, a nucleating agent, an antistatic agent, an antiblocking agent, a pigment, and a colorant. Be done.

The thickness of the first base material layer and the second base material layer is not particularly limited, but is generally preferably 1 to 300 μm or less, and preferably 20 to 200 μm from the viewpoint of workability such as strength and handleability. It is more preferably 30 to 120 μm.

When the first retardation layer with a base material layer has a first orientation layer, or when the second retardation layer with a base material layer has a second orientation layer, the first base material layer and the first orientation layer are in close contact with each other. In order to improve the properties and the adhesion between the second base material layer and the second orientation layer, at least the surface of the first base material layer on the side where the first orientation layer is formed, and at least the second base material. Corona treatment, plasma treatment, flame treatment, or the like may be performed on the surface of the layer on the side where the second alignment layer is formed, or a primer layer or the like may be formed.

(1st bonding layer, 2nd bonding layer, 3rd bonding layer)
The first bonding layer, the second bonding layer, and the third bonding layer can be an adhesive curing layer or an adhesive layer, respectively. The adhesive cured layer can be formed by using the adhesive composition, and the pressure-sensitive adhesive layer can be formed by using the pressure-sensitive adhesive composition. The second bonded layer is preferably an adhesive cured layer. The first bonding layer may be either an adhesive curing layer or an adhesive layer, but in order to increase the Martens hardness H2 of the optical laminate, it is preferably an adhesive curing layer. The third bonding layer is preferably an adhesive layer. The first bonded layer, the second bonded layer, and the third bonded layer may have the same thickness or different thicknesses.

(Adhesive hardened layer)
The adhesive curing layer refers to an adhesive curing layer formed by curing a curable component in an adhesive composition. The thickness of the adhesive cured layer is usually 20 μm or less, preferably 10 μm or less, more preferably 5 μm or less, and particularly preferably 3 μm or less. If the thickness of the adhesive curing layer is excessively large, the reaction rate of the curable component in the adhesive composition tends to decrease, and the moisture and heat resistance of the optical laminate tends to deteriorate. The thickness of the adhesive cured layer is usually 0.01 μm or more, preferably 0.1 μm or more.

The storage elastic modulus of the adhesive cured layer is preferably 1200 MPa or more, more preferably 1400 MPa or more, and even more preferably 1900 MPa or more. When the storage elastic modulus of the adhesive cured layer is 1200 MPa or less, the adhesive cured layer is soft and easily deformed, so that the surface of the optical laminate 1 is easily scratched. When the storage elastic modulus of the adhesive cured layer is large, the adhesive cured layer is hard and hard to be deformed, so that the surface of the optical laminate 1 can be hard to be scratched. When forming an adhesive cured layer from an adhesive composition, an adhesive cured layer having a low storage elastic modulus can be obtained by adding a polymer or a component having a long molecular chain between functional groups to the adhesive composition. When a polyfunctional component, particularly a component having a short molecular chain between functional groups, is added, the distance between the cross-linking points after curing becomes short, and an adhesive cured layer having a large storage elastic modulus tends to be easily obtained. be. The storage elastic modulus of the adhesive cured layer is a value at a temperature of 23 ° C. and a relative humidity of 55%, and can be measured in Examples described later.

Examples of the adhesive composition for forming the adhesive layer include adhesives other than pressure-sensitive adhesives (adhesives), such as water-based adhesives and active energy ray-curable adhesives.

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

Examples of the active energy ray-curable adhesive include solvent-free active energy ray-curable adhesives containing a curable component that is cured by irradiation with active energy rays such as ultraviolet rays, visible light, electron beams, and X-rays. Can be mentioned. By using a solvent-free active energy ray-curable adhesive, the adhesion between layers can be improved. On the other hand, when the active energy ray-curable adhesive contains a solvent (particularly an organic solvent), sufficient adhesion is obtained even if the curable components contained in the adhesive composition are the same. When the optical laminate is cut to a predetermined size, problems such as peeling at the end thereof are likely to occur.

When an active energy ray-curable adhesive is used, the adhesive curing layer is formed by, for example, irradiating a coating layer of the active energy ray-curable adhesive with active energy rays to cure the curable component. Can be done. The light source of the active energy ray may be, for example, one that generates ultraviolet rays, electron beams, X-rays, or the like. The active energy ray is preferably ultraviolet light. As the ultraviolet light source, a light source having an emission distribution having a wavelength of 400 nm or less is preferable, and examples thereof include a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a chemical lamp, a black light lamp, a microwave-excited mercury lamp, and a metal halide lamp. be able to.

The intensity of the active energy ray irradiation to the coating layer of the active energy ray-curable adhesive is determined for each type of the active energy ray-curable adhesive, but the light irradiation in the wavelength range effective for activating the photopolymerization initiator is determined. It is preferable that the strength is 0.1 to 1000 mW / cm ^2. If the light irradiation intensity is too low, the reaction time becomes too long, while if the light irradiation intensity is too high, the heat radiated from the lamp and the heat generated during the polymerization of the curable component cause yellowing of the adhesive curing layer. And deterioration of each layer constituting the optical laminate may occur. The light irradiation time to the coating layer is also controlled for each type of active energy ray-curable adhesive, but the integrated light amount expressed as the product of the light irradiation intensity and the light irradiation time is 10 to 5000 mJ / cm ² . It is preferable that the setting is as follows. If the integrated light intensity is too small, the active species derived from the photopolymerization initiator may not be sufficiently generated, and the resulting adhesive cured layer may be insufficiently cured. On the other hand, if the integrated light intensity is too large, the integrated light intensity may be insufficient. The light irradiation time becomes very long, which tends to be disadvantageous for improving productivity.

Examples of the active energy ray-curable adhesive include a radically polymerizable adhesive containing a radically polymerizable compound as a curable component, a cationically polymerizable adhesive containing a cationically polymerizable compound as a curable component, and the like.

(Radical polymerizable adhesive)
The radically polymerizable compound contained in the radically polymerizable adhesive refers to a compound or an oligomer in which the radical polymerization reaction proceeds by irradiation or heating with active energy rays and is cured, specifically, a compound having an ethylenically unsaturated bond. Can be mentioned. Compounds having an ethylenically unsaturated bond include (meth) acrylic compounds having one or more (meth) acryloyl groups in the molecule, styrene, styrene sulfonic acid, vinyl acetate, vinyl propionate, and N-vinyl. Examples thereof include vinyl compounds such as -2-pyrrolidone. Among them, the preferred radically polymerizable compound is a (meth) acrylic compound.

The (meth) acrylic compound is obtained by reacting two or more kinds of a (meth) acrylate monomer having at least one (meth) acryloyloxy group in the molecule, a (meth) acrylamide monomer, and a functional group-containing compound. Examples thereof include (meth) acryloyl group-containing compounds such as (meth) acrylic oligomers having at least two (meth) acryloyl groups in the molecule. The (meth) acrylic oligomer is preferably a (meth) acrylate oligomer having at least two (meth) acryloyloxy groups in the molecule. As the (meth) acrylic compound, only one kind may be used alone, or two or more kinds may be used in combination.

The (meth) acrylate monomer includes a monofunctional (meth) acrylate monomer having one (meth) acryloyloxy group in the molecule and a bifunctional (meth) acrylate having two (meth) acryloyloxy groups in the molecule. Examples include monomers and polyfunctional (meth) acrylate monomers having three or more (meth) acryloyloxy groups in the molecule.

Examples of monofunctional (meth) acrylate monomers include alkyl (meth) acrylates. In an alkyl (meth) acrylate, the alkyl group may be linear or branched as long as it has 3 or more carbon atoms. Specific examples of alkyl (meth) acrylates include methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, and the like. Examples thereof include 2-ethylhexyl (meth) acrylate. Also, aralkyl (meth) acrylates such as benzyl (meth) acrylates; (meth) acrylates of terpen alcohols such as isobornyl (meth) acrylates; (meth) having a tetrahydrofurfuryl structure such as tetrahydrofurfuryl (meth) acrylates. ) Acrylate; has a cycloalkyl group at the alkyl group moiety such as cyclohexyl (meth) acrylate, cyclohexylmethyl methacrylate, dicyclopentanyl acrylate, dicyclopentenyl (meth) acrylate, 1,4-cyclohexanedimethanol monoacrylate (meth). ) Acrylate; Aminoalkyl (meth) acrylate such as N, N-dimethylaminoethyl (meth) acrylate; 2-phenoxyethyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, ethyl carbitol (meth) acrylate , (Meta) acrylate having an ether bond at the alkyl moiety such as phenoxypolyethylene glycol (meth) acrylate can also be used as the monofunctional (meth) acrylate monomer.

Further, a monofunctional (meth) acrylate having a hydroxyl group at the alkyl moiety and a monofunctional (meth) acrylate having a carboxyl group at the alkyl moiety can also be used. Specific examples of the monofunctional (meth) acrylate having a hydroxyl group at the alkyl moiety include 2-hydroxyethyl (meth) acrylate, 2- or 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 2-hydroxy. -3-Phenoxypropyl (meth) acrylate, trimethylolpropane mono (meth) acrylate, pentaerythritol mono (meth) acrylate are included. Specific examples of the monofunctional (meth) acrylate having a carboxyl group at the alkyl moiety include 2-carboxyethyl (meth) acrylate, ω-carboxy-polycaprolactone (n≈2) mono (meth) acrylate, 1- [2- ( Meta) acryloyloxyethyl] phthalic acid, 1- [2- (meth) acryloyloxyethyl] hexahydrophthalic acid, 1- [2- (meth) acryloyloxyethyl] succinic acid, 4- [2- (meth) acryloyl Oxyethyl] Trimellitic acid, N- (meth) acryloyloxy-N', N'-dicarboxymethyl-p-phenylenediamine.

The (meth) acrylamide monomer is preferably (meth) acrylamide having a substituent at the N-position, and a typical example of the substituent at the N-position is an alkyl group, but the nitrogen atom of (meth) acrylamide. The ring may form a ring with the ring, and the ring may have an oxygen atom as a ring member in addition to the carbon atom and the nitrogen atom of (meth) acrylamide. Further, a substituent such as alkyl or oxo (= O) may be bonded to the carbon atom constituting the ring.

Specific examples of N-substituted (meth) acrylamide include N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, Nn-butyl (meth) acrylamide, and Nt. N-alkyl (meth) acrylamide such as -butyl (meth) acrylamide, N-hexyl (meth) acrylamide; N, N such as N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide. − Dialkyl (meth) acrylamide includes. Further, the N-substituted group may be an alkyl group having a hydroxyl group, and examples thereof include N-hydroxymethyl (meth) acrylamide, N- (2-hydroxyethyl) (meth) acrylamide, and N- (2-hydroxy). Examples thereof include propyl) (meth) acrylamide. Furthermore, specific examples of the N-substituted (meth) acrylamide forming the above-mentioned 5-membered ring or 6-membered ring include N-acryloylpyrrolidine, 3-acryloyl-2-oxazolidinone, 4-acryloylmorpholine, and N-acryloyl. Examples thereof include piperidine and N-methacryloyl piperidine.

Examples of the bifunctional (meth) acrylate monomer include alkylene glycol di (meth) acrylate, polyoxyalkylene glycol di (meth) acrylate, halogen-substituted alkylene glycol di (meth) acrylate, aliphatic polyol di (meth) acrylate, and hydrogenation. Di (meth) acrylate of dicyclopentadiene or tricyclodecanedialkanol, di (meth) acrylate of dioxane glycol or dioxandialkanol, di (meth) acrylate of alkylene oxide adduct of bisphenol A or bisphenol F, bisphenol A or bisphenol Examples thereof include the epoxy di (meth) acrylate of F.

More specific bifunctional (meth) acrylate monomers include ethylene glycol di (meth) acrylate, 1,3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, and 1,6-. Hexadiol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethyl propandi (meth) acrylate, pentaerythritol di (meth) acrylate, ditrimethylol propandi (Meta) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (Meta) acrylate, polytetramethylene glycol di (meth) acrylate, silicone di (meth) acrylate, di (meth) acrylate of hydroxypivalate neopentyl glycol ester, 2,2-bis [4- (meth) acryloyloxyethoxy Ethoxyphenyl] propane, 2,2-bis [4- (meth) acryloyloxyethoxyethoxycyclohexyl] propane, hydrogenated dicyclopentadienyldi (meth) acrylate, tricyclodecanedimethanol di (meth) acrylate, 1, 3-Dioxane-2,5-diyldi (meth) acrylate [also known as dioxane glycol di (meth) acrylate], acetal compound of hydroxypivalaldehyde and trimethylolpropane [Chemical name: 2- (2-hydroxy-1,2, 1-Dimethylethyl) -5-ethyl-5-hydroxymethyl-1,3-dioxane] di (meth) acrylate, tris (hydroxyethyl) isocyanurate di (meth) acrylate and the like can be mentioned.

Examples of the trifunctional or higher functional polyfunctional (meth) acrylate monomer include glycerin tri (meth) acrylate, alkoxylated glycerin tri (meth) acrylate, trimethyl propantri (meth) acrylate, ditrimethylol propanthry (meth) acrylate, and ditrimethylol. Propanetetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, etc. Poly (meth) acrylates of trifunctional or higher functional aliphatic polyols are typical, and in addition, poly (meth) acrylates of trifunctional or higher functional halogen-substituted polyols and tri (meth) alkylene oxide adducts of glycerin are used. Acrylate, tri (meth) acrylate of alkylene oxide adduct of trimethylolpropane, 1,1,1-tris [(meth) acryloyloxyethoxyethoxy] propane, tris (hydroxyethyl) isocyanurate tri (meth) acrylate and the like. Be done.

On the other hand, examples of the (meth) acrylic oligomer include urethane (meth) acrylic oligomer, polyester (meth) acrylic oligomer, and epoxy (meth) acrylic oligomer.

A urethane (meth) acrylic oligomer is a compound having a urethane bond (-NHCOO-) and at least two (meth) acryloyl groups in the molecule. Specifically, a urethanization reaction product of a hydroxyl group-containing (meth) acrylic monomer having at least one (meth) acryloyl group and at least one hydroxyl group in the molecule and polyisocyanate, or a polyol as polyisocyanate. It can be a urethanization reaction product of a terminal isocyanato group-containing urethane compound obtained by reaction and a (meth) acrylic monomer having at least one (meth) acryloyl group and at least one hydroxyl group in the molecule. ..

The hydroxyl group-containing (meth) acrylic monomer used in the urethanization reaction can be, for example, a hydroxyl group-containing (meth) acrylate monomer, and specific examples thereof include 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (. Meta) Acrylate, 2-Hydroxybutyl (Meta) Acrylate, 2-Hydroxy-3-phenoxypropyl (Meta) Acrylate, Glycerindi (Meta) Acrylate, Trimethylol Propane Di (Meta) Acrylate, Pentaerythritol Tri (Meta) Acrylate, Contains dipentaerythritol penta (meth) acrylate. Specific examples other than the hydroxyl group-containing (meth) acrylate monomer include N-hydroxyalkyl (meth) acrylamide monomers such as N-hydroxyethyl (meth) acrylamide and N-methylol (meth) acrylamide.

Examples of the polyisocyanate used for the urethanization reaction with the hydroxyl group-containing (meth) acrylic monomer include hexamethylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate, and among these diisocyanates, aromatic ones. Diisocyanates obtained by hydrogenating isocyanates (for example, hydrogenated tolylene diisocyanates, hydrogenated xylylene diisocyanates, etc.), di- or tri-isocyanates such as triphenylmethane triisocyanates, dibenzylbenzene triisocyanates, and the above. Examples thereof include polyisocyanate obtained by increasing the amount of diisocyanate.

Further, as the polyol used to obtain a terminal isocyanato group-containing urethane compound by reaction with polyisocyanate, a polyester polyol, a polyether polyol, or the like can be used in addition to an aromatic, aliphatic or alicyclic polyol. can. Examples of aliphatic and alicyclic polyols include 1,4-butanediol, 1,6-hexanediol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, neopentyl glycol, trimethylolethane, trimethylolpropane, and ditri. Examples thereof include methylolpropane, pentaerythritol, dipentaerythritol, dimethylolheptan, dimethylolpropionic acid, dimethylolbutanoic acid, glycerin, hydrogenated bisphenol A and the like.

The polyester polyol is obtained by a dehydration condensation reaction between the above-mentioned polyol and a polybasic carboxylic acid or an anhydride thereof. Examples of polybasic carboxylic acids or their anhydrides, which may be anhydrides, are represented by adding "(anhydride)" to (anhydrous) succinic acid, adipic acid, (anhydrous) maleic acid, (anhydrous). Examples thereof include itaconic acid, (anhydrous) trimellitic acid, (anhydrous) pyromellitic acid, (anhydrous) phthalic acid, isophthalic acid, terephthalic acid, and hexahydro (anhydrous) phthalic acid.

Examples of the polyether polyol include polyalkylene glycols, polyoxyalkylene-modified polyols obtained by reacting the above-mentioned polyols or dihydroxybenzenes with alkylene oxides, and the like.

A polyester (meth) acrylic oligomer is a compound having an ester bond and at least two (meth) acryloyl groups (typically (meth) acryloyloxy groups) in the molecule. Specifically, it can be obtained by a dehydration condensation reaction using (meth) acrylic acid, a polybasic carboxylic acid or an anhydride thereof, and a polyol. Examples of polybasic carboxylic acids or their anhydrides used in the dehydration condensation reaction, which can be anhydrous, are represented by adding "(anhydride)" to (anhydrous) succinic acid, adipic acid, (anhydride). There are maleic acid, (anhydrous) itaconic acid, (anhydrous) trimellitic acid, (anhydrous) pyromellitic acid, hexahydro (anhydrous) phthalic acid, (anhydrous) phthalic acid, isophthalic acid, terephthalic acid and the like. Examples of the polyol used in the dehydration condensation reaction include 1,4-butanediol, 1,6-hexanediol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, neopentyl glycol, trimethylolethane, and trimethylolpropane. Examples thereof include ditrimethylolpropane, pentaerythritol, dipentaerythritol, dimethylolheptan, dimethylolpropionic acid, dimethylolbutanoic acid, glycerin, and hydrogenated bisphenol A.

The epoxy (meth) acrylic oligomer can be obtained, for example, by an addition reaction between polyglycidyl ether and (meth) acrylic acid, and has at least two (meth) acryloyloxy groups in the molecule. Examples of the polyglycidyl ether used in the addition reaction include ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, and bisphenol A diglycidyl ether.

The radically polymerizable adhesive may further contain the cationically polymerizable compound contained in the cationically polymerizable adhesive described later, in addition to the radically polymerizable compound. When the total amount of curable components contained in the radically polymerizable adhesive is 100% by weight, the content of the cationically polymerizable compound (or the total content of two or more kinds of cationically polymerizable compounds when they are contained) is determined. In 100% by weight of the polymerizable component, it is preferably 50% by weight or less, more preferably 40% by weight or less, and further preferably 30% by weight or less.

The radically polymerizable adhesive preferably contains a photoradical polymerization initiator in addition to a curable component such as a radically polymerizable compound. The photoradical polymerization initiator initiates the polymerization reaction of a radical curable compound by irradiation with active energy rays such as visible light, ultraviolet rays, X-rays, or electron beams. Only one type of photoradical polymerization initiator may be used alone, or two or more types may be used in combination.

Specific examples of photoradical initiators include acetophenone, 3-methylacetophenone, benzyldimethylketal, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 2-methyl-1-[ Acetphenone-based initiators such as 4- (methylthio) phenyl-2-morpholinopropane-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one; benzophenone, 4-chlorobenzophenone, 4,4'. -Benzophenone-based initiators such as diaminobenzophenone; benzoin ether-based initiators such as benzoinpropyl ether and benzoin ethyl ether; thioxanthone-based initiators such as 4-isopropylthioxanthone; ..

The blending amount of the photoradical polymerization initiator is usually 0.5 to 20 parts by weight, preferably 1 to 6 parts by weight, based on 100 parts by weight of the radically polymerizable compound. By blending 0.5 parts by weight or more of the photoradical polymerization initiator, the radically polymerizable compound can be sufficiently cured, and high mechanical strength and adhesive strength can be imparted to the obtained optical laminate. On the other hand, if the amount is excessively large, the durability of the optical laminate may decrease.

The radically polymerizable adhesive may contain other additives, if desired. Specific examples of additives include ion trapping agents, antioxidants, chain transfer agents, polymerization accelerators (polyols, etc.), sensitizers, sensitizing aids, light stabilizers, tackifiers, thermoplastic resins, fillers. , Flow conditioner, plasticizer, antifoaming agent, leveling agent, silane coupling agent, dye, antistatic agent, ultraviolet absorber and the like. Examples of the ion trap agent include powdered bismuth-based, antimony-based, magnesium-based, aluminum-based, calcium-based, titanium-based and mixed-based inorganic compounds, and examples of the antioxidant include hindered phenol-based antioxidants. And so on.

(Cation-polymerizable adhesive)
The cationically polymerizable compound contained in the cationically polymerizable adhesive refers to a compound or oligomer in which the cationic polymerization reaction proceeds and is cured by irradiation or heating with active energy rays such as ultraviolet rays, visible light, electron beams, and X-rays, and is an epoxy. Examples thereof include compounds, oxetane compounds, and vinyl compounds. Among them, the preferred cationically polymerizable compound is an epoxy compound. The epoxy compound is a compound having one or more, preferably two or more epoxy groups in the molecule. Only one type of epoxy compound may be used alone, or two or more types may be used in combination. Examples of the epoxy compound include an alicyclic epoxy compound, an aromatic epoxy compound, a hydrogenated epoxy compound, and an aliphatic epoxy compound. Among them, from the viewpoint of weather resistance, curing speed and adhesiveness, the epoxy compound preferably contains an alicyclic epoxy compound or an aliphatic epoxy compound, and more preferably contains an alicyclic epoxy compound.

The alicyclic epoxy compound is a compound having one or more epoxy groups bonded to the alicyclic ring in the molecule. The "epoxy group bonded to the alicyclic ring" means a bridging oxygen atom-O-in the structure represented by the following formula (I). In the following formula (I), m is an integer of 2 to 5.

_{A compound in which one or more hydrogen atoms in (CH 2} ) _m in the above formula (I) are removed and a group in which a group is bonded to another chemical structure can be an alicyclic epoxy compound. One or more hydrogen atoms in (CH ₂ ) _m may be appropriately substituted with a linear alkyl group such as a methyl group or an ethyl group.

Among them, the alicyclic epoxy compound having an epoxycyclopentane structure [m = 3 in the above formula (I)] and an epoxycyclohexane structure [m = 4 in the above formula (I)] is a cured glass. The transition temperature is high, which is also advantageous in terms of adhesiveness between the layers. Specific examples of the alicyclic epoxy compound are given below. Here, the compound names are listed first, and then the chemical formulas corresponding to the respective compounds are shown, and the compound names and the corresponding chemical formulas are given the same reference numerals.

A: 3,4-Epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate,
B: 3,4-Epoxy-6-Methylcyclohexylmethyl 3,4-Epoxy-6-methylcyclohexanecarboxylate,
C: Ethylene bis (3,4-epoxycyclohexanecarboxylate),
D: Bis (3,4-epoxycyclohexylmethyl) adipate,
E: Bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate,
F: Diethylene glycol bis (3,4-epoxycyclohexylmethyl ether),
G: Ethylene glycol bis (3,4-epoxycyclohexylmethyl ether),
H: 2,3,14,15-Diepoxy-7,11,18,21-Tetraoxatrispyro [5.2.2.5.2.2] Heneicosane,
I: 3- (3,4-epoxycyclohexyl) -8,9-epoxy-1,5-dioxaspiro [5.5] undecane,
J: 4-Vinylcyclohexene dioxide,
K: Limonene Geoxide,
L: Vis (2,3-epoxycyclopentyl) ether,
M: Dicyclopentadiene dioxide.

An aromatic epoxy compound is a compound having an aromatic ring and an epoxy group in the molecule. Specific examples thereof include bisphenol type epoxy compounds such as bisphenol A diglycidyl ether, bisfer F diglycidyl ether, and bisphenol S diglycidyl ether or oligomers thereof; phenol novolac epoxy resin, cresol novolac epoxy resin, hydroxybenzaldehyde phenol novolac. Novolac type epoxy resin such as epoxy resin; polyfunctional epoxy such as 2,2', 4,4'-tetrahydroxydiphenylmethane glycidyl ether, 2,2', 4,4'-tetrahydroxybenzophenone glycidyl ether Compound: Includes a polyfunctional epoxy resin such as epoxidized polyvinylphenol.

The hydrogenated epoxy compound is a glycidyl ether of a polyol having an alicyclic ring, and is a nuclear hydrogenated poly obtained by selectively hydrogenating an aromatic polyol on an aromatic ring under pressure in the presence of a catalyst. It can be a glycidyl etherified hydroxy compound. Specific examples of aromatic polyols include bisphenol-type compounds such as bisphenol A, bisphenol F, and bisphenol S; novolak-type resins such as phenol novolac resin, cresol novolac resin, and hydroxybenzaldehyde phenol novolac resin; tetrahydroxydiphenylmethane and tetrahydroxy. Contains polyfunctional compounds such as benzophenone and polyvinylphenol. A glycidyl ether can be obtained by reacting an alicyclic polyol obtained by hydrogenating the aromatic ring of an aromatic polyol with epichlorohydrin. Among the hydrogenated epoxy compounds, the diglycidyl ether of hydrogenated bisphenol A can be mentioned.

The aliphatic epoxy compound is a compound having at least one oxylan ring (three-membered cyclic ether) bonded to an aliphatic carbon atom in the molecule. For example, monofunctional epoxy compounds such as butyl glycidyl ether and 2-ethylhexyl glycidyl ether; bifunctional such as 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether and neopentyl glycol diglycidyl ether. Epoxide compounds; Trifunctional or higher functional epoxy compounds such as trimethylolpropan triglycidyl ether and pentaerythritol tetraglycidyl ether; with one epoxy group directly bonded to the alicyclic ring such as 4-vinylcyclohexendioxide and limonendioxide. , Epoxide compounds having an oxylane ring bonded to an aliphatic carbon atom and the like. Of these, a bifunctional epoxy compound (also referred to as an aliphatic diepoxy compound) having two oxylan rings bonded to an aliphatic carbon atom in the molecule is preferable from the viewpoint of adhesiveness between the polarizing film and the protective film. Such a suitable aliphatic diepoxy compound can be represented by, for example, the following formula (II).

Y in the above formula (II) is an alkylene group having 2 to 9 carbon atoms, an alkylene group having 4 to 9 total carbon atoms intervening an ether bond, or a divalent group having 6 to 18 carbon atoms having an alicyclic structure. It is a hydrocarbon group of.

Specifically, the aliphatic diepoxy compound represented by the above formula (II) is a diglycidyl ether of an alkanediol, a diglycidyl ether of an oligoalkylene glycol up to about 4 repetitions, or a diglycidyl ether of an alicyclic diol. Is.

Specific examples of the diol (glycol) capable of forming the aliphatic diepoxy compound represented by the above formula (II) are listed below. Alcandiols include ethylene glycol, propylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, and 1,4-butanediol. , Neopentyl glycol, 3-methyl-2,4-pentanediol, 2,4-pentanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentane Diol, 2,4-diethyl-1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 3,5-heptandiol, 1,8-octanediol, 2-methyl-1,8 There are −octanediol, 1,9-nonanediol and the like. Examples of the oligoalkylene glycol include diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol and the like. Examples of the alicyclic diol include cyclohexanediol and cyclohexanedimethanol.

An oxetane compound, which is one of the cationically polymerizable compounds, is a compound containing one or more oxetane rings (oxetanyl groups) in the molecule, and specific examples thereof are 3-ethyl-3-hydroxymethyloxetane (oxetane alcohol). Also called), 2-ethylhexyloxetane, 1,4-bis [{(3-ethyloxetane-3-yl) methoxy} methyl] benzene (also called xylylenebis oxetane), 3-ethyl-3 [{( 3-Ethyloxetane-3-yl) methoxy} methyl] oxetane, 3-ethyl-3- (phenoxymethyl) oxetane, 3- (cyclohexyloxy) methyl-3-ethyloxetane. The oxetane compound may be used as the main component of the cationically polymerizable compound, or may be used in combination with the epoxy compound. The combined use of an oxetane compound may improve the curing rate and adhesiveness.

Examples of vinyl compounds that can be cationically polymerizable compounds include aliphatic or alicyclic vinyl ether compounds, and specific examples thereof include n-amyl vinyl ether, i-amyl vinyl ether, n-hexyl vinyl ether, and n-octyl vinyl ether. , 2-Ethylhexyl vinyl ether, n-dodecyl vinyl ether, stearyl vinyl ether, oleyl vinyl ether and other alkyl or alkenyl vinyl ethers with 5 to 20 carbon atoms; and hydroxyl groups such as 2-hydroxyethyl vinyl ether, 3-hydroxypropyl vinyl ether and 4-hydroxybutyl vinyl ether. Containing vinyl ether; monoalcohol vinyl ether having an aliphatic ring or aromatic ring such as cyclohexyl vinyl ether, 2-methylcyclohexylvinyl ether, cyclohexylmethylvinyl ether, benzylvinyl ether; glycerol monovinyl ether, 1,4-butanediol monovinyl ether, 1,4 -Butanediol divinyl ether, 1,6-hexanediol divinyl ether, neopentyl glycol divinyl ether, pentaerythritol divinyl ether, pentaerythritol tetravinyl ether, trimethylolpropane divinyl ether, trimethylolpropanetrivinyl ether, 1,4-dihydroxycyclohexanemono Mono-polyvinyl ethers of polyhydric alcohols such as vinyl ether, 1,4-dihydroxycyclohexanedivinyl ether, 1,4-dihydroxymethylcyclohexanemonovinyl ether, 1,4-dihydroxymethylcyclohexanedivinyl ether; diethylene glycol divinyl ether, triethylene glycol divinyl ether , Polyalkylene glycol mono to divinyl ethers such as diethylene glycol monobutyl monovinyl ethers; other vinyl ethers such as glycidyl vinyl ethers and ethylene glycol vinyl ether methacrylates. The vinyl compound may be used as a main component of the cationically polymerizable compound, or may be used in combination with an epoxy compound, or an epoxy compound and an oxetane compound. By using a vinyl compound in combination, it may be possible to improve the curing speed and the viscosity reduction of the adhesive.

The cationically polymerizable adhesive can contain curable components other than the cationically polymerizable compound and the radically polymerizable compound. Examples of other curable components include lactone compounds, cyclic acetal compounds, cyclic thioether compounds, spiro orthoester compounds and the like.

When the total amount of the curable component contained in the cationically polymerizable adhesive is 100% by weight, the content of the cationically polymerizable compound (or the total content of two or more kinds of cationically polymerizable compounds when they are contained) is determined. , 80% by weight or more, more preferably 90% by weight or more, still more preferably 100% by weight.

The cationically polymerizable adhesive preferably contains a photocationic polymerization initiator in addition to a curable component such as a cationically polymerizable compound. The photocationic polymerization initiator generates a cationic species or Lewis acid by irradiation with active energy rays such as visible light, ultraviolet rays, X-rays, or electron beams, and initiates a polymerization reaction of a cationically curable compound. .. Since the photocationic polymerization initiator acts catalytically with light, it is excellent in storage stability and workability even when mixed with a photocationic curable compound. Examples of the compound that produces a cationic species or Lewis acid by irradiation with active energy rays include onium salts such as aromatic iodonium salts and aromatic sulfonium salts, aromatic diazonium salts, and iron-alene complexes.

The aromatic iodonium salt is a compound having a diaryliodonium cation, and examples of the cation include a diphenyliodonium cation. The aromatic sulfonium salt is a compound having a triarylsulfonium cation, and examples of the cation include a triphenylsulfonium cation and a 4,4'-bis (diphenylsulfonio) diphenylsulfide cation. The aromatic diazonium salt is a compound having a diazonium cation, and examples of the cation include a benzenediazonium cation. Also, the iron-arene complex is typically a cyclopentadienyl iron (II) arene cationic complex salt.

The cations shown above are paired with anions (anions) to form a photocationic polymerization initiator. Examples of anions which constitute the photo-cationic polymerization initiator, a special phosphorus based anions _{[(Rf) n PF 6-} n] -, hexafluorophosphate anion PF ₆ ^-, hexafluoroantimonate anion SbF ₆ ^-, pentafluorophenyl hydroxy antimonate anion SbF ₅ (OH) ^-, hexafluoro ah cell anions AsF ₆ ^-, tetrafluoroborate anion BF ₄ ^-, tetrakis (pentafluorophenyl) borate anion _{B (C 6 F 5) 4} - and the like. Among them, from the viewpoint of safety of the curability and the resulting adhesive layer of the cationically polymerizable compound, a special phosphate based anionic _{[(Rf) n PF 6-} n] -, hexafluorophosphate anion PF ₆ ^- is preferably ..

As the photocationic polymerization initiator, only one kind may be used alone, or two or more kinds may be used in combination. Among them, the aromatic sulfonium salt is preferably used because it has an ultraviolet absorbing property even in a wavelength region near 300 nm, and thus can give a cured product having excellent curability and good mechanical strength and adhesive strength.

The blending amount of the photocationic polymerization initiator is usually 0.5 to 10 parts by weight, preferably 6 parts by weight or less, based on 100 parts by weight of the cationically polymerizable compound. By blending 0.5 parts by weight or more of the photocationic polymerization initiator, the cationically polymerizable compound can be sufficiently cured, and high mechanical strength and adhesive strength can be imparted to the obtained polarizing plate. On the other hand, if the amount is excessively large, the amount of ionic substances in the cured product increases, so that the hygroscopicity of the cured product increases, and the durability of the polarizing plate may decrease.

The cationically polymerizable adhesive may contain other additives, if desired. Examples of the additive include the additives described above as additives that can be contained in the radically polymerizable adhesive.

(Adhesive layer)
The pressure-sensitive adhesive layer refers to a layer formed by using a pressure-sensitive adhesive composition containing a pressure-sensitive adhesive. In the present specification, the "adhesive" exhibits adhesiveness by sticking itself to an adherend such as a polarizing plate or a liquid crystal layer, and is a so-called pressure-sensitive adhesive. .. Further, the active energy ray-curable pressure-sensitive adhesive described later can adjust the degree of cross-linking and the adhesive force by irradiating with energy rays.

The thickness of the pressure-sensitive adhesive layer is preferably 3 μm or more, and more preferably 5 μm or more. The thickness of the pressure-sensitive adhesive layer is preferably 40 μm or less, and more preferably 30 μm or less. The above-mentioned upper limit value and lower limit value can be arbitrarily combined.

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

The pressure-sensitive adhesive layer may be formed by using an active energy ray-curable pressure-sensitive adhesive. The active energy ray-curable pressure-sensitive adhesive is a harder pressure-sensitive adhesive by blending a pressure-sensitive adhesive composition with an ultraviolet-curable compound such as a polyfunctional acrylate, forming a pressure-sensitive adhesive layer, and then irradiating the pressure-sensitive adhesive with ultraviolet rays to cure the pressure-sensitive adhesive. Layers can be formed. The active energy ray-curable pressure-sensitive adhesive has a property of being cured by being irradiated with energy rays such as ultraviolet rays and electron beams. Since the activated energy ray-curable adhesive has adhesiveness even before irradiation with energy rays, it adheres to an adherend such as an optical film or a liquid crystal layer, and is cured by irradiation with energy rays to improve adhesion. A pressure-sensitive adhesive having adjustable properties.

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

(Release film)
The release film is provided so as to be removable from the third bonding layer. The release film is particularly preferably used when the third bonding layer is a pressure-sensitive adhesive layer, and is used to cover and protect the pressure-sensitive adhesive layer or to support the pressure-sensitive adhesive layer. Examples of the release film include a film in which the surface of the base film on the pressure-sensitive adhesive layer side is subjected to a mold release treatment such as a silicone treatment. Examples of the resin material forming the base film include the same resin materials as those forming the protective layer described above. The resin film may have a one-layer structure or may be a multilayer resin film having a multilayer structure of two or more layers.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these examples. Unless otherwise specified, "%" and "part" in Examples and Comparative Examples are mass% and parts by mass.

In order to obtain the optical laminates described in Examples, Comparative Examples, and Reference Examples, each material was prepared as follows.

[Preparation of linearly polarized light layer]
A polyvinyl alcohol film having a thickness of 30 μm (average degree of polymerization of about 2400, saponification degree of 99 mol% or more) was uniaxially stretched about 5 times by dry stretching, and further kept in a tense state in pure water at 60 ° C. for 1 minute. After the immersion, the mixture was immersed in an aqueous solution at 28 ° C. having a weight ratio of iodine / potassium iodide / water of 0.05 / 5/100 for 60 seconds. Then, it was immersed in an aqueous solution at 72 ° C. having a weight ratio of potassium iodide / boric acid / water of 8.5 / 8.5 / 100 for 300 seconds. Subsequently, the film was washed with pure water at 26 ° C. for 20 seconds and then dried at 65 ° C. to obtain a linearly polarized light layer having a thickness of 12 μm in which iodine was adsorbed and oriented on the polyvinyl alcohol film.

[Preparation of water-based adhesive]
An aqueous polyvinyl alcohol solution was prepared by dissolving 3 parts of carboxyl group-modified polyvinyl alcohol (“KL-318” manufactured by Kuraray Co., Ltd.) in 100 parts of water. A water-soluble polyamide epoxy resin (“Sumirace Resin 650 (30)” manufactured by Taoka Chemical Industry Co., Ltd., solid content concentration 30% by weight) was added to the obtained aqueous solution at a ratio of 1.5 parts to 100 parts of water. Mixing gave an aqueous adhesive.

[Preparation of adhesive layer (a) with double-sided release film]
95.0 parts of n-butyl acrylate, 4.0 parts of acrylate, 1.0 part of 2-hydroxyethyl acrylate in a reaction vessel equipped with a stirrer, thermometer, reflux condenser, dropping device and nitrogen introduction tube. , 200 parts of ethyl acetate, and 0.08 part of 2,2'-azobisisobutyronitrile were charged, and the air in the reaction vessel was replaced with nitrogen gas. The reaction solution was heated to 60 ° C. with stirring under a nitrogen atmosphere, reacted for 6 hours, and then cooled to room temperature. When the weight average molecular weight of a part of the obtained solution was measured, it was confirmed that 1.8 million (meth) acrylic acid ester polymers were produced.

100 parts of (meth) acrylic acid ester polymer obtained in the above step (solid content conversion value; the same applies hereinafter) and trimethylolpropane-modified tolylene diisocyanate (manufactured by Toso Co., Ltd., trade name "Coronate") as an isocyanate-based cross-linking agent. (Registered Trademark) L ") 1.5 parts, 3-glycidoxypropyltrimethoxysilane (manufactured by Shinetsu Chemical Industry Co., Ltd., trade name" KBM403 ") 0.30 parts as a silane coupling agent, and UV curing 7.5 parts of ethoxylated isocyanurate triacrylate (manufactured by Shin-Nakamura Chemical Industry Co., Ltd .: product name "A-9300") as a sex compound and 2-methyl-1- (4-methylthiophenyl) -2 as a photopolymerization initiator. -Coating the pressure-sensitive adhesive composition by mixing 0.5 part of -morpholinopropane-1-one (BASF: Irgacure (registered trademark) 907), stirring well, and diluting with ethyl acetate. A solution was obtained.

The release-treated surface (release layer surface) of the release film (manufactured by Lintec Corporation: SP-PLR382190) is coated with the coating solution obtained above by an applicator so that the thickness after drying is 5 μm. After that, it was dried at 100 ° C. for 1 minute to form a coating layer after drying. Another release film (manufactured by Lintec Corporation: SP-PLR38131) was attached to the surface opposite to the surface to which the release film of the coating layer after drying was attached. After that, using an ultraviolet irradiation device with a belt conveyor (manufactured by Fusion UV Systems, the lamp uses a D bulb), ultraviolet rays (irradiation intensity 500 mW / cm ² , integrated light intensity 500 mJ) were applied to the dried coating layer through the separator. / Cm ² ) was irradiated to form an adhesive layer (a) from the dried coating layer to obtain an adhesive layer (a) with a double-sided separator.

[Preparation of first retardation layer with base material layer]
A first retardation layer with a substrate layer having a first substrate layer and a first retardation layer, which are transparent substrates, was prepared. The first retardation layer was a laminate of the first alignment layer and the first liquid crystal layer obtained by curing the nematic liquid crystal compound, and had a 1/4 wavelength retardation characteristic. The thickness of the first retardation layer was 2 μm.

[Preparation of UV curable adhesive (b)]
Dipentaerythritol hexaacrylate (A-DPH manufactured by Shin Nakamura Chemical Industry Co., Ltd.) 80.0 parts, polyethylene glycol di (meth) acrylate (A-200 manufactured by Shin Nakamura Chemical Industry Co., Ltd.) 20.0 parts, 3.0 parts of Darocur 1173 (Darocur 1173 manufactured by BASF) was mixed as a photopolymerization initiator to prepare an ultraviolet curable adhesive (b). The storage elastic modulus of the obtained cured film obtained by curing the ultraviolet curable adhesive (b) by the following procedure was measured at a temperature of 23 ° C. and a relative humidity of 55% and found to be 2000 MPa.

[Measurement of storage elastic modulus]
Apply UV curable adhesive (b) to one side of a polyethylene terephthalate (PET) film (ester film E7002, manufactured by Toyo Boseki Co., Ltd.) using a coating machine (bar coater, manufactured by Daiichi Rika Co., Ltd.). ^{Then, ultraviolet rays were irradiated with an integrated light amount of 1500 mJ / cm 2} by a D valve manufactured by Fusion UV Systems, Inc. to cure the ultraviolet curable adhesive (b). This was cut into 1 cm × 8 cm, and the PET film was peeled off to obtain an independently cured film of the ultraviolet curable adhesive (b). Hold the obtained single film on the upper and lower grips of a tensile tester (AUTOGRAPH AG-1S, manufactured by Shimadzu Corporation) at a distance of 5 cm so that the long side is in the pulling direction, and the temperature is 23 ° C. The elastic modulus was calculated from the initial straight line of the stress-strain curve by data processing software (TRAPEZIUM2, manufactured by Shimadzu Corporation) in an environment of 55% relative humidity and a tensile speed of 10 mm / min.

Each evaluation of the second retardation layer and the optical laminate was carried out by the following procedure.

[Measurement of Martens hardness H1 of the second retardation layer]
The second retardation layer with a base material layer obtained in Examples, Comparative Examples, and Reference Examples was cut out to a size of 40 mm × 40 mm, and the pressure-sensitive adhesive layer with a double-sided release film obtained above was placed on the second retardation layer side. One of the release films (a) was peeled off and the exposed surface of the pressure-sensitive adhesive layer (a) was bonded. Subsequently, the surface of the pressure-sensitive adhesive layer (a) exposed by peeling off the other release film attached to the pressure-sensitive adhesive layer (a) was bonded to a glass plate having a size of 40 mm × 40 mm. Then, the second base material layer of the second retardation layer with the base material layer was peeled off to obtain a measurement sample (1). In the measurement sample (1), the glass, the pressure-sensitive adhesive layer (a), and the second retardation layer were laminated in this order. In an atmosphere of a temperature of 23 ° C. and a relative humidity of 55%, an ultrafine hardness tester (FISCHERSCOPE HM2000: manufactured by Fisher Instruments Co., Ltd.) was applied to the surface of the measurement sample (1) on the second retardation layer side. After applying a load at a pressurizing speed of 1 mN / 5 seconds using did.

[Measurement of Martens hardness H2 of optical laminate]
The optical laminates obtained in Examples, Comparative Examples, and Reference Examples were cut into a size of 40 mm × 40 mm, and the adhesive with a double-sided release film obtained above was placed on the polarizing plate side (surface of the protective film) of the optical laminate. One of the release films of the layer (a) was peeled off and the exposed surface of the pressure-sensitive adhesive layer (a) was bonded. Subsequently, the surface of the adhesive layer (a) exposed by peeling off the other release film attached to the adhesive layer (a) is attached to a glass plate having a size of 40 mm × 40 mm for measurement. Sample (2) was obtained. The measurement sample (2) is obtained by laminating glass, an adhesive layer (a), and an optical laminate in this order, and the outer surface of the measurement sample (2) on the optical laminate side has a second phase difference. It was the surface on the layer side. In an atmosphere of a temperature of 23 ° C. and a relative humidity of 55%, an ultrafine hardness tester (FISCHERSCOPE HM2000: manufactured by Fisher Instruments Co., Ltd.) was applied to the surface of the measurement sample (2) on the second retardation layer side. After applying a load at a pressurizing speed of 1 mN / 5 seconds, the Martens hardness measured with the creep time (time to maintain a load of 1 mN) as 5 s was defined as the Martens hardness H2 of the optical laminate. ..

[Abrasion test]
The optical laminates obtained in Examples, Comparative Examples, and Reference Examples were cut into a size of 100 mm × 100 mm, and the adhesive with a double-sided release film obtained above was placed on the polarizing plate side (surface of the protective film) of the optical laminate. One of the release films of the layer (a) was peeled off and the exposed surface of the pressure-sensitive adhesive layer (a) was bonded. The surface of the pressure-sensitive adhesive layer (a) exposed by peeling off the other release film attached to the pressure-sensitive adhesive layer (a) is bonded to a glass plate having a size of 100 mm × 100 mm, and a sample for measurement ( 3) was obtained. In an atmosphere of a temperature of 23 ° C. and a relative humidity of 55%, a non-woven fabric Bencot M-3II (manufactured by Asahi Kasei Co., Ltd.) was used to make a 25 mm × 25 mm surface on the surface of the measurement sample (3) on the second retardation layer side. The bottom surface of the metal block having a square flat surface as the bottom surface was covered. While pressing the bottom surface of this metal block (bottom surface covered with non-woven fabric) against the surface of the measurement sample (3) on the second retardation layer side with a load of 250 g / cm ² , a distance of 7 cm is 5 m / cm. After making 10 reciprocations linearly at a speed of min, the state of the surface on the second retardation layer side was visually observed. The number of scratches in the region having a width of 20 mm orthogonal to the reciprocating direction of the metal block in the region where the non-woven fabric was reciprocated was visually counted to determine the number of scratches [strips / 20 mm], and the evaluation was performed according to the following criteria. The scratches on the measurement sample (3) were all linear scratches along the reciprocating direction of the non-woven fabric.
A: No scratches or few scratches were observed.
B: More than a dozen scratches (more than 10 to 20 or less [lines / 20 mm]) were observed.
C: Dozens of scratches (more than 20 to 30 or less [lines / 20 mm]) were observed.
D: Many scratches (more than 30 [books / 20 mm]) were observed.

[Example 1]
(Making a polarizing plate with a protective film)
The water-based adhesive prepared above is applied to one surface side of the linearly polarized light layer (thickness 12 μm) obtained above, and a protective layer (triacetyl cellulose (TAC) film manufactured by Konica Minolta Co., Ltd. (thickness 20 μm, wavelength). In-plane retardation value at 590 nm: 1.2 nm, thickness direction retardation value at wavelength of 590 nm: 1.3 nm)) were bonded together. A protective layer (cycloolefin resin (COP) film manufactured by Nippon Zeon Co., Ltd. (thickness 25 μm, wavelength 590 nm)) coated with the water-based adhesive prepared above on the other surface side of the linear polarizing layer. A COP film with a surface treatment layer coated with a surface treatment agent manufactured by Nippon Paper Industries Co., Ltd. to a thickness of 3 μm) was attached to the inner phase difference value (140 nm). This was dried at a temperature of 80 ° C. for 5 minutes to obtain a polarizing plate having protective layers on both sides of the linearly polarizing layer. A protective film was attached to the surface-treated protective layer (COP film with surface-treated layer) side of the obtained polarizing plate, and cured at a temperature of 40 ° C. for 168 hours to obtain a polarizing plate with a protective film.

(Preparation of polarizing plate with adhesive layer)
An adhesive layer exposed by peeling one of the release films of the double-sided release film (a) obtained above on the polarizing plate side (protective layer side of the TAC film) of the obtained polarizing plate with a protective film. The surface of (a) was bonded, and then the other release film was peeled off to obtain a polarizing plate with an adhesive layer. The polarizing plate with the pressure-sensitive adhesive layer had a protective film, a polarizing plate, and a pressure-sensitive adhesive layer (a) in this order.

(Preparation of second retardation layer with base material layer)
10.0 parts of polyethylene glycol di (meth) acrylate, 10.0 parts of trimethylolpropane triacrylate, 10.0 parts of 1,6-hexanediol di (meth) acrylate, and Irgacure 907 as a photopolymerization initiator. 50 parts were dissolved in 70.0 parts of methyl ethyl ketone as a solvent to prepare a composition for forming an orientation layer.

A composition for forming a liquid crystal layer is prepared by dissolving 20.0 parts of a photopolymerizable nematic liquid crystal compound and 1.0 part of Irgacure 907 as a photopolymerization initiator in 80.0 parts by weight of a solvent propylene glycol monomethyl ether acetate. did.

One side of the second base material layer (long-shaped cyclic olefin resin film having a thickness of 20 μm) is subjected to corona treatment, and the composition for forming an orientation layer prepared above is applied to the corona-treated surface with a bar coater. The first coating layer was formed. After heat-treating the first coating layer at a temperature of 80 ° C. for 60 seconds, the composition for forming an orientation layer is polymerized and cured by irradiating with ultraviolet rays, and the first coating layer having a thickness of 1.8 μm is placed on the second base material layer. A bi-oriented layer was formed. The liquid crystal layer forming composition prepared above was applied onto the second alignment layer to form a second coating layer. After heat-treating the second coating layer at a temperature of 80 ° C. for 60 seconds, the composition for forming a liquid crystal layer is polymerized and cured by irradiating with ultraviolet rays, and a second coating layer having a thickness of 0.7 μm is placed on the second oriented layer. A liquid crystal layer was formed. As a result, a second retardation layer (1) with a base material layer having a second base material layer, a second orientation layer, and a second liquid crystal layer in this order was obtained. The Martens hardness H1 of the second retardation layer was measured using the second retardation layer (1) with a base material layer. The results are shown in Table 1.

(Preparation of optical laminate (1))
Corona treatment was applied to the first retardation layer side of the first retardation layer with the base material layer prepared above and the second retardation layer side of the second retardation layer (1) with the base material layer, respectively. .. The ultraviolet curable adhesive (b) prepared above is applied to one of the corona-treated surfaces, and the first retardation layer with a base material layer and the second retardation layer (1) with a base material layer are bonded together. After that, the ultraviolet curable adhesive (b) was cured by irradiating with ultraviolet rays to form an adhesive curable layer which is a second bonding layer. As a result, the first base material layer, the first retardation layer (first alignment layer, first liquid crystal layer), the second bonding layer (adhesive curing layer), and the second retardation layer (second liquid crystal layer, second liquid crystal layer). A laminated body (1) in which a two-oriented layer) and a second base material layer were laminated in this order was obtained.

After the exposed surface exposed by peeling off the first base material layer of the laminate (1) obtained above and the pressure-sensitive adhesive layer (a) of the polarizing plate with the pressure-sensitive adhesive layer are bonded together, the second base material By peeling off the layer, an optical laminate (e1) was obtained. The peeling interface when the first base material layer is peeled off is between the first base material layer and the first oriented layer, and the peeling interface when the second base material layer is peeled off is the second oriented layer and the first oriented layer. It was between two liquid crystal layers. The optical laminate (e1) includes a protective film, a polarizing plate, a first bonding layer (adhesive layer (a)), a first alignment layer, a first liquid crystal layer, a second bonding layer (adhesive curing layer), and the like. And the second liquid crystal layer was provided in this order. The Martens hardness H2 was measured on the obtained optical laminate (e1), and a scratch resistance test was performed. The results are shown in Table 1.

[Example 2]
A polarizing plate with a protective film and a laminate (1) were prepared according to the procedure described in Example 1. The polarizing plate side (protective layer side of the TAC film) of the polarizing plate with the protective film and the exposed surface exposed by peeling off the first base material layer of the laminated body (1) are bonded to each other by the ultraviolet curable adhesive prepared above. Example 1 and Example 1 except that the agent (b) was used for bonding and the ultraviolet curable adhesive (b) was cured by irradiating with ultraviolet rays to form an adhesive curing layer which is the first bonding layer. In the same procedure, an optical laminate (e2) was obtained. The optical laminate (e2) includes a protective film, a polarizing plate, a first bonding layer (adhesive curing layer), a first alignment layer, a first liquid crystal layer, a second bonding layer (adhesive curing layer), and a first layer. It had two liquid crystal layers in this order. The Martens hardness H2 was measured on the obtained optical laminate (e2), and a scratch resistance test was performed. The results are shown in Table 1.

[Comparative Example 1]
The first retardation layer with a base material layer and the second retardation layer (1) with a base material layer are bonded to each other by forming the pressure-sensitive adhesive layer (a) of the pressure-sensitive adhesive layer (a) with a double-sided release film obtained above. An optical laminate (c1) was obtained in the same procedure as in Example 1 except that the laminate (2) was obtained by using the product. The obtained optical laminate (c1) includes a protective film, a polarizing plate, a first bonding layer (adhesive layer (a)), a first alignment layer, a first liquid crystal layer, and a second bonding layer (adhesive layer). (A)) and the second liquid crystal layer were provided in this order. The Martens hardness H2 was measured on the obtained optical laminate (c1), and a scratch resistance test was performed. The results are shown in Table 1.

[Example 3]
Preparation of the second retardation layer (1) with a base material layer according to Example 1 except that one side of the second base material layer (long-shaped cyclic olefin resin film having a thickness of 20 μm) is not subjected to corona treatment. A second retardation layer (2) with a base material layer was obtained in the same manner as in the procedure. Optical lamination is performed as the same procedure as in Example 1 except that the obtained second retardation layer (2) with a base material layer and the laminate (1) produced by the procedure described in Example 1 are used. The body (e3) was obtained. The peeling interface when the second base material layer was peeled off was between the second base material layer and the second orientation layer. The obtained optical laminate (e3) has a protective film, a polarizing plate, a first bonding layer (adhesive layer (a)), a first alignment layer, a first liquid crystal layer, and a second bonding layer (adhesive curing). The layer), the second liquid crystal layer, and the second oriented layer were provided in this order. Using the obtained second retardation layer (2) with a base material layer, the Martens hardness H1 of the second retardation layer was measured, and the Martens hardness H2 of the optical laminate (e3) was measured and scratched. A sex test was performed. The results are shown in Table 1.

[Comparative Example 2]
Examples except that the second retardation layer (2) with a base material layer was prepared by the procedure described in Example 3, the laminate (2) was prepared by the procedure described in Comparative Example 1, and these were used. An optical laminate (c2) was obtained in the same procedure as in 1. The peeling interface when the second base material layer was peeled off was between the second base material layer and the second orientation layer. The obtained optical laminate (c2) includes a protective film, a polarizing plate, a first bonding layer (adhesive layer (a)), a first alignment layer, a first liquid crystal layer, and a second bonding layer (adhesive layer). (A)), the second liquid crystal layer, and the second oriented layer were provided in this order. The Martens hardness H2 was measured on the obtained optical laminate (c2), and a scratch resistance test was performed. The results are shown in Table 1.

[Reference Example 1]
The procedure for producing the second retardation layer (2) with a base material layer described in Example 3 is the same as the procedure for producing the second retardation layer (2) with a base material layer, except that the thickness of the second orientation layer formed on the second base material layer is 2.2 μm. , A second retardation layer (3) with a base material layer was obtained. Optical lamination is performed as the same procedure as in Example 1 except that the obtained second retardation layer (3) with a base material layer and the laminate (2) produced by the procedure described in Comparative Example 1 are used. The body (r1) was obtained. The peeling interface when the second base material layer was peeled off was between the second base material layer and the second orientation layer. The obtained optical laminate (r1) includes a protective film, a polarizing plate, a first bonding layer (adhesive layer (a)), a first alignment layer, a first liquid crystal layer, and a second bonding layer (adhesive layer). (A)), the second liquid crystal layer, and the second oriented layer were provided in this order. Using the obtained second retardation layer (3) with a base material layer, the Martens hardness H1 of the second retardation layer was measured, and the Martens hardness H2 was measured for the obtained optical laminate (r1). And a scratch resistance test was conducted. The results are shown in Table 1.

[Reference example 2]
Examples except that the second retardation layer (3) with a base material layer was prepared by the procedure described in Reference Example 1, the laminate (1) was prepared by the procedure described in Example 1, and these were used. An optical laminate (r2) was obtained in the same procedure as in 1. The peeling interface when the second base material layer was peeled off was between the second base material layer and the second orientation layer. The obtained optical laminate (r2) has a protective film, a polarizing plate, a first bonding layer (adhesive layer (a)), a first alignment layer, a first liquid crystal layer, and a second bonding layer (adhesive curing). The layer), the second liquid crystal layer, and the second oriented layer were provided in this order. The Martens hardness H2 was measured on the obtained optical laminate (r2), and a scratch resistance test was performed. The results are shown in Table 1.

[Reference Example 3]
The procedure for producing the second retardation layer (2) with a base material layer described in Example 3 is the same as the procedure for producing the second retardation layer (2) with a base material layer, except that the thickness of the second orientation layer formed on the second base material layer is 5.0 μm. , A second retardation layer (4) with a base material layer was obtained. Optical lamination is performed as the same procedure as in Example 1 except that the obtained second retardation layer (4) with a base material layer and the laminate (2) produced by the procedure described in Comparative Example 1 are used. A body (r3) was obtained. The peeling interface when the second base material layer was peeled off was between the second base material layer and the second orientation layer. The obtained optical laminate (r3) includes a protective film, a polarizing plate, a first bonding layer (adhesive layer (a)), a first alignment layer, a first liquid crystal layer, and a second bonding layer (adhesive layer). (A)), the second liquid crystal layer, and the second oriented layer were provided in this order. Using the obtained second retardation layer (4) with a base material layer, the Martens hardness H1 of the second retardation layer was measured, and the Martens hardness H2 was measured for the obtained optical laminate (r3). And a scratch resistance test was conducted. The results are shown in Table 1.

[Reference Example 4]
A second retardation layer (4) with a base material layer was prepared according to the procedure described in Reference Example 3, a laminate (1) was prepared according to the procedure described in Example 1, and examples were used except that these were used. An optical laminate (r4) was obtained in the same procedure as in 1. The peeling interface when the second base material layer was peeled off was between the second base material layer and the second orientation layer. The obtained optical laminate (r4) has a protective film, a polarizing plate, a first bonding layer (adhesive layer (a)), a first alignment layer, a first liquid crystal layer, and a second bonding layer (adhesive curing). The layer), the second liquid crystal layer, and the second oriented layer were provided in this order. The Martens hardness H2 was measured on the obtained optical laminate (r4), and a scratch resistance test was performed. The results are shown in Table 1.

1,1a, 1b optical laminate, 3,3a, 3b optical laminate with laminated layer, 10 first retardation layer, 11 first alignment layer, 12 first liquid crystal layer, 15 first base material layer, 18 groups 1st retardation layer with material layer, 20 2nd retardation layer, 21 2nd alignment layer, 22 2nd liquid crystal layer, 25 2nd base material layer, 28 2nd retardation layer with base material layer, 31 1st attachment Laminated layer, 32 2nd bonded layer, 33 3rd bonded layer, 35 release film, 36 bonded layer with release film, 40 polarizing plate, 51 transport roll, 53 bonded roll.

Claims (12)

An optical laminate having a polarizing plate having protective layers on one or both sides of a linearly polarized light layer, a first retardation layer, and a second retardation layer in this order.
The first retardation layer includes a first liquid crystal layer which is a cured product layer of a polymerizable liquid crystal compound.
The second retardation layer includes a second liquid crystal layer which is a cured product layer of a polymerizable liquid crystal compound.
The Martens hardness H1 of the second retardation layer at a pressurizing speed of 1 mN / 5s and a creep time of 5s is 10 N / mm ² or less.
The ratio (H2 / H1) of the Martens hardness H2 to the Martens hardness H1 at a pressurizing speed of 1 mN / 5s and a creep time of 5s on the second retardation layer side of the optical laminate is 15 or more. Optical laminate. An optical laminate having a polarizing plate having protective layers on one or both sides of a linearly polarized light layer, a first retardation layer, and a second retardation layer in this order.
The first retardation layer includes a first liquid crystal layer which is a cured product layer of a polymerizable liquid crystal compound.
The second retardation layer includes a second liquid crystal layer which is a cured product layer of a polymerizable liquid crystal compound.
The Martens hardness H1 of the second retardation layer at a pressurizing speed of 1 mN / 5s and a creep time of 5s is 10 N / mm ² or less.
An optical laminate in which the number of scratches on the second retardation layer side of the optical laminate by the scratch resistance test is 10/20 mm or less. The first retardation layer and the second retardation layer are bonded via a second bonding layer.
The optical laminate according to claim 1 or 2, wherein the second bonding layer is an adhesive curing layer. The optical laminate according to claim 3, wherein the adhesive cured layer constituting the second bonding layer is a cured layer of an active energy ray-curable adhesive. The polarizing plate and the first retardation layer are bonded via a first bonding layer.
The optical laminate according to any one of claims 1 to 4, wherein the first bonding layer is an adhesive curing layer or an adhesive layer. The optical laminate according to claim 5, wherein the first bonding layer is an adhesive cured layer, and the adhesive cured layer is a cured layer of an active energy ray-curable adhesive. The optical laminate according to any one of claims 1 to 6, wherein the first retardation layer is a laminate of the first liquid crystal layer and the first alignment layer. The second retardation layer is a laminate of the second liquid crystal layer and the second alignment layer.
The optical laminate according to any one of claims 1 to 7, wherein the second alignment layer is provided on the side of the second liquid crystal layer opposite to the first retardation layer side. An optical laminate with a laminating layer having the optical laminate according to any one of claims 1 to 8 and a third laminating layer.
The third bonding layer is an optical laminate with a bonding layer provided on the side of the second retardation layer opposite to the first retardation layer side. The optical lamination with a bonding layer according to claim 9, wherein the third bonding layer has a release film that can be peeled off from the third bonding layer on the side opposite to the second retardation layer side. body. The method for manufacturing an optical laminate with a bonding layer according to claim 9 or 10.
A step of transporting the optical laminate while bringing the transport roll into contact with the second retardation layer side of the optical laminate.
A method for producing an optical laminate with a bonded layer, which comprises a step of forming the third bonded layer on the second retardation layer side of the optical laminated body after the transfer step. The method for manufacturing an optical laminate with a bonding layer according to claim 11, further comprising a step of laminating a release film on the side of the third bonding layer opposite to the second retardation layer side.

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