TWI809198B - Liquid crystal layer laminate - Google Patents

Abstract

An objective of the present invention is to provide an optical laminate in which reverse curling is suppressed, a liquid crystal layer laminate used for producing the optical laminate, and production methods thereof.

As a solution, the present invention provides a method for producing a liquid crystal layer laminate which includes the following steps: preparing a first liquid crystal layer with base material layer having a first base material layer and a first liquid crystal layer formed by polymerizing a polymerizable liquid crystal compound on the first base material layer; preparing a second liquid crystal layer with base material layer having a second base material layer and a second liquid crystal layer formed by polymerizing a polymerizable liquid crystal compound on the second base material layer; and laminating the second liquid crystal layer side of the second liquid crystal layer with second base material layer on the first liquid crystal layer side of the first liquid crystal layer with base material layer via a first adhesive layer. The first adhesive layer is an adhesive cured layer made of a cured product of a curable adhesive, the absolute value of the curl amount of the first liquid crystal layer is within 20 mm, and the absolute value of the curl amount of the second liquid crystal layer is within 20 mm.

Description

Liquid crystal laminate

The present invention relates to a liquid crystal layered body, and also relates to an optical layered body, and their manufacturing methods.

Compared with liquid crystal display devices, organic EL display devices using organic light-emitting diodes (OLEDs) can not only achieve light weight and thinner, but also realize high-quality images such as wide viewing angles, fast response speeds, and high contrast. quality, it is used in various fields such as smartphones, TVs, and digital cameras. In an organic EL display device, it is known that a circular polarizing plate or the like is used to improve the anti-reflection performance because the reduction in visibility due to reflection of an external light source can be suppressed.

For example, in Patent Documents 1 and 2, as a film with antireflection function used in image display panels such as organic EL display devices, a laminate is disclosed, which is based on a linear polarizing plate (optical film) and has two layers. Retardation layers formed of liquid crystal compounds and laminated with interposed layers.

Patent Document 1: Japanese Patent Laid-Open No. 2015-230386

Patent Document 2: Japanese Unexamined Patent Publication No. 2015-79256

The above-mentioned film is bonded to the optical display element and used, but if such a film is bent so that the side to be bonded to the optical display element becomes concave, that is, when a so-called rollback occurs, the bonded film and the optical display element Occasionally, air bubbles permeate, and wrinkles also occur. Due to these problems, defects such as unevenness tend to be easily recognized. Such a defect can cause a defect of an image display panel, so it is desired to suppress the film from being wound up.

An object of the present invention is to provide an optical layered body in which curling is suppressed, a liquid crystal layered body used in the manufacture of the optical layered body, and a method for producing the same.

[1] A method for manufacturing a liquid crystal layered body, the liquid crystal layered system at least sequentially laminated with a first liquid crystal layer, a first adhesive layer, and a second liquid crystal layer, the manufacturing method comprising the following steps:

The step of preparing the first liquid crystal layer with the base material layer, the first liquid crystal layer with the base material layer has the first base material layer, and the aforementioned second liquid crystal compound formed by polymerizing the polymerizable liquid crystal compound on the aforementioned first base material layer a liquid crystal layer;

The step of preparing a second liquid crystal layer with a base material layer, the second liquid crystal layer with a base material layer has a second base material layer, and the aforementioned first liquid crystal compound formed by polymerizing a polymerizable liquid crystal compound on the aforementioned second base material layer two liquid crystal layers; and

The layering step is to laminate the second liquid crystal layer side of the second liquid crystal layer attached to the second base material layer on the first liquid crystal layer side of the first liquid crystal layer attached to the aforementioned base material layer through the aforementioned first adhesive layer, in,

The aforementioned first adhesive layer is an adhesive hardened layer composed of a hardened product of a curable adhesive,

The absolute value of the curling amount of the aforementioned first liquid crystal layer is within 20mm,

The absolute value of the amount of curl of the second liquid crystal layer is within 20 mm.

[2] The method for producing a liquid crystal laminate as described in [1], wherein the storage modulus (storage modulus) of the first adhesive layer at a temperature of 30° C. is E [Pa], and the thickness is When t[m] is used, the first adhesive layer satisfies the relationship of the following formula (1).

3000≦E×t≦15000 (1)

[3] The method for producing a liquid crystal laminate according to [1] or [2], further comprising a step of peeling off the first base material layer after the lamination step.

[4] A liquid crystal laminate, which is a liquid crystal laminate in which at least a first liquid crystal layer, a first adhesive layer, and a second liquid crystal layer are sequentially laminated, wherein,

The aforementioned first liquid crystal layer and the aforementioned second liquid crystal layer are cured layers of polymerizable liquid crystal compounds,

The aforementioned first adhesive layer is an adhesive hardened layer composed of a cured product of a curable adhesive,

The absolute value of the curling amount of the aforementioned first liquid crystal layer is within 20mm,

The absolute value of the amount of curl of the second liquid crystal layer is within 20 mm.

[5] The liquid crystal laminate described in [4], wherein when the storage elastic modulus of the first adhesive layer at a temperature of 30° C. is E [Pa] and the thickness is t [m], The aforementioned first adhesive layer satisfies the relationship of the following formula (1).

3000≦E×t≦15000 (1)

[6] The liquid crystal laminate according to [4] or [5], further comprising a second base material layer on the side opposite to the first adhesive layer of the second liquid crystal layer.

[7] The liquid crystal laminate according to [6], further comprising a first base material layer on the side opposite to the first adhesive layer of the first liquid crystal layer.

[8] A method of manufacturing an optical laminate, the optical layer system at least sequentially laminated with an optical film, a second adhesive layer, a first liquid crystal layer, a first adhesive layer, and a second liquid crystal layer, the manufacturing method comprising the following step:

On the side of the first exposed surface exposed by peeling off the first substrate layer of the liquid crystal laminate manufactured by the method for producing a liquid crystal laminate described in [3], by using the liquid crystal described in [7] Step of peeling off the first exposed surface side exposed by the first substrate layer, or the first liquid crystal layer side of the liquid crystal laminated body described in [6], and sequentially laminating the second adhesive layer and the optical film .

[9] The method for producing an optical laminate described in [8], further comprising the step of peeling off the second base material layer after the step of sequentially laminating the second adhesive layer and the optical film.

[10] The method for manufacturing an optical laminate as described in [9], further comprising the following steps:

A step of preparing an adhesive layer with a release layer laminated with an adhesive layer and a release layer; and

A step of laminating the adhesive layer side of the adhesive layer with a release layer on the second exposed surface side exposed by peeling off the second base material layer.

[11] The method for producing an optical laminate according to [10], further comprising a step of peeling off the release layer after the step of laminating the adhesive layer with release layer on the side of the adhesive layer.

[12] The method for producing an optical laminate according to any one of [8] to [11], wherein the optical film includes a polarizing plate.

[13] An optical laminate, which is an optical laminate in which at least an optical film, a second adhesive layer, a first liquid crystal layer, a first adhesive layer, and a second liquid crystal layer are laminated in this order, wherein,

The aforementioned first liquid crystal layer and the aforementioned second liquid crystal layer are cured layers of polymerizable liquid crystal compounds,

The aforementioned first adhesive layer is an adhesive hardened layer composed of a cured product of a curable adhesive,

The absolute value of the curling amount of the aforementioned first liquid crystal layer is within 20mm,

The absolute value of the amount of curl of the second liquid crystal layer is within 20 mm.

[14] The optical laminate described in [13], wherein when the storage elastic modulus of the first adhesive layer at a temperature of 30°C is E[Pa] and the thickness is t[m], the above-mentioned The first adhesive layer satisfies the relationship of the following formula (1).

3000≦E×t≦15000 (1)

[15] The optical laminate according to [13] or [14], further comprising a second base material layer on the side opposite to the first adhesive layer of the second liquid crystal layer.

[16] The optical laminate according to [13] or [14], further comprising an adhesive layer on the side opposite to the first adhesive layer of the second liquid crystal layer.

[17] The optical laminate according to [16], further comprising a release layer on the side of the pressure-sensitive adhesive layer opposite to the second liquid crystal layer.

[18] The optical laminate according to any one of [13] to [17], wherein the optical film includes a polarizing plate.

According to the present invention, it is possible to manufacture an optical laminate in which curling is suppressed.

10‧‧‧First liquid crystal layer with substrate layer

11‧‧‧The first substrate layer

12‧‧‧First liquid crystal layer

20‧‧‧Second liquid crystal layer with substrate layer

21‧‧‧Second substrate layer

22‧‧‧Second liquid crystal layer

25‧‧‧Second liquid crystal layer with composition layer

31‧‧‧The first bonding layer

31a‧‧‧adhesive composition layer

32‧‧‧Second bonding layer

33‧‧‧adhesive layer

40‧‧‧Liquid crystal laminate with double-sided substrate layers (liquid crystal laminate)

41‧‧‧Liquid crystal laminate with a single surface material layer (liquid crystal laminate)

50‧‧‧Second adhesive layer with release layer

51‧‧‧First peeling layer

53‧‧‧Second peeling layer

58‧‧‧Adhesive layer with release layer

60‧‧‧optical film

61‧‧‧Optical film with second adhesive layer

70‧‧‧Optical laminate with substrate layer peeled off (optical laminate)

71‧‧‧Optical laminate with substrate layer (optical laminate)

72‧‧‧Optical laminate with release layer (optical laminate)

73‧‧‧Optical laminate with adhesive layer (optical laminate)

Fig. 1 (a) to (d) are schematic cross-sectional views schematically showing an example of the manufacturing steps of the liquid crystal laminate of the present invention.

Fig. 2 (a) and (b) are schematic cross-sectional views schematically showing subsequent steps of manufacturing the liquid crystal laminate shown in Fig. 1 .

Fig. 3 (a) to (c) are schematic cross-sectional views schematically showing an example of the manufacturing steps of the optical layered body of the present invention.

Fig. 4 (a) and (b) are schematic cross-sectional views schematically showing subsequent steps of manufacturing the optical layered body shown in Fig. 3 .

Fig. 5 is a schematic cross-sectional view schematically showing the subsequent steps of manufacturing the optical layered body shown in Fig. 4 .

Fig. 6 (a) and (b) are schematic cross-sectional views schematically showing subsequent steps of manufacturing the optical layered body shown in Fig. 5 .

Hereinafter, preferred embodiments of the optical layered body, the liquid crystal layered body, and their production methods of the present invention will be described with reference to the drawings. Figures 1 and 2 are schematic cross-sectional views schematically showing an example of the manufacturing steps of the method for manufacturing a liquid crystal laminated body of this embodiment, and Figures 3 to 6 are schematic cross-sectional views showing optical components of this embodiment. A schematic cross-sectional view of an example of the manufacturing steps of the manufacturing method of the laminate. W in the figure represents the width direction.

(Optical laminate)

As shown in FIG. 4 and FIG. 6, the optical layering system of this embodiment at least sequentially laminates an optical film 60, a second adhesive layer 32, a first liquid crystal layer 12, a first adhesive layer 31, and a second liquid crystal layer. 22. Here, the first adhesive layer is an adhesive cured layer composed of a cured product of a curable adhesive. Moreover, the first liquid crystal layer 12 and the second liquid crystal layer 22 are cured layers of polymerizable liquid crystal compounds, the first liquid crystal layer 12 can be formed by polymerizing the polymerizable liquid crystal compound on the first substrate layer 11, and the second liquid crystal layer 22 available on the second basis It is formed by polymerizing a polymerizable liquid crystal compound on the material layer 21. In the optical laminate, the absolute value of the curl amount of the first liquid crystal layer is within 20 mm, and the absolute value of the curl amount of the second liquid crystal layer is within 20 mm.

In this specification, the amount of curling of the first liquid crystal layer 12 and the second liquid crystal layer 22 is such that the length of the long side is 150 mm, the length of the short side is 50 mm, and the long side is in the distance from the optical laminate. In the first liquid crystal layer or the second liquid crystal layer cut out with the TD direction at an angle of 45 degrees, it is evaluated that in its diagonal, the extension direction is relatively close to the direction parallel to the above TD direction of the optical laminate. The curl generated on the diagonal is calculated by the procedure described in the examples described later.

The amount of curling of the first liquid crystal layer 12 and the second liquid crystal layer 22 can be determined by the type of the polymerizable liquid crystal compound used to form the first liquid crystal layer 12 and the second liquid crystal layer 22, the polymer (hardening degree) of the polymerizable liquid crystal compound ), the types of additives contained in the composition for forming the liquid crystal layer, etc. are adjusted. The degree of polymerization of the polymeric liquid crystal compound can be determined by the type or amount of the polymerization initiator, reactive additive, polymerization inhibitor, etc. contained in the composition for forming the liquid crystal layer, and the activity of irradiation when the polymerizable liquid crystal compound is polymerized and hardened. The irradiation intensity or irradiation time (irradiation amount) of the energy ray is adjusted. The absolute values of the curl amounts of the first liquid crystal layer 12 and the second liquid crystal layer 22 are preferably independently 15 mm or less, more preferably 12 mm or less, more preferably 9 mm or less, or 0 mm, and preferably 1 mm or more, more preferably 3 mm or more. The smaller the absolute value of the amount of curling, the more it can suppress the curling deformation (hereinafter, also referred to as "recurl") that bends into a bow with the second liquid crystal layer 22 side as the inner side, and the easier it is to make the optical laminate into a plane ( flat) state.

As shown in Figure 6(b), it has a layer structure of an optical film 60, a second adhesive layer 32, a first liquid crystal layer 12, a first adhesive layer 31, a second liquid crystal layer 22, and an adhesive layer 33 in sequence. The optical laminated body 73 (optical laminated body) with an adhesive layer is used for bonding the adhesive layer 33 to an optical display element. At this time, in the optical laminated body 73 with the adhesive layer attached, if a reverse roll occurs (with the adhesive layer 33 side as the inside Bow-shaped deformation) tends to cause defects such as unevenness due to air bubbles and wrinkles when it is bonded to an optical display element. However, since the absolute value of the curling amount of the first liquid crystal layer 12 and the second liquid crystal layer 22 of the optical laminate 73 with the adhesive layer is 20 mm or less, the occurrence of curling can be suppressed, and bonding to the optical display element can be suppressed. The above-mentioned unfavorable situations that arise when

The reason is presumed as follows. The first liquid crystal layer 12 and the second liquid crystal layer 22 (hereinafter, both are also referred to as "liquid crystal layers") included in the optical laminate 73 with an adhesive layer can be formed by On the base material layer 11 and the second base material layer 21 (hereinafter, both are also collectively referred to as "base layer"), a composition for forming a liquid crystal layer containing a polymerizable liquid crystal compound is applied and dried, It is formed by irradiating active energy rays to polymerize and harden the polymerizable liquid crystal compound. It is presumed that in the liquid crystal layer formed through the above-mentioned steps of coating, drying, polymerization, curing, etc., residues caused by the drying of the coated liquid crystal layer forming composition or the curing of the polymerization of the polymerizable liquid crystal compound remain. The resulting shrinkage force. In the state where the liquid crystal layer exists on the base layer, the above-mentioned shrinkage stress is suppressed by the base layer, but the base layer is generally peeled off in a step of manufacturing a liquid crystal laminate or an optical laminate. Therefore, it is considered that the shrinkage stress of the liquid crystal layer is released when the base layer is peeled off, and the liquid crystal layer is affected by the released shrinkage stress, deforming the optical laminate 73 with the adhesive layer to cause curling.

The optical laminated body 73 with the adhesive layer shown in FIG. 6 (b) has the first liquid crystal layer 12 and the second liquid crystal layer 22 interposed only on one side of the optical film 60 showing higher rigidity. In such a configuration, since the shrinkage stress remaining in the liquid crystal layers acts to cause the optical layered body 73 with the adhesive layer to curl inward from the liquid crystal layer side, it tends to be rolled back easily.

Therefore, in the optical laminated body 73 with the adhesive layer of this embodiment, the absolute value of the above-mentioned amount of curl is 20 mm or less for the first liquid crystal layer 12 and the second liquid crystal layer 22 . Thus, it is presumed that even if the first liquid crystal layer 12 or the second liquid crystal is released due to peeling off the first base material layer 11 or the second base material layer 21 The shrinkage stress of the layer 22 can also suppress the deformation of the liquid crystal layers. As a result, the optical laminated body 73 with the pressure-sensitive adhesive layer can also be suppressed from being rolled back.

Preferably, when the storage elastic modulus of the first adhesive layer 31 at a temperature of 30°C is set as E[Pa], and the thickness is set as t[m], the first adhesive layer 31 has the following formula (1): rigidity of the relationship.

3000≦E×t≦15000 (1)

The value of E×t in the above formula (1) is preferably 3500 [Pa. s] or more, more preferably 4000 [Pa. s] or more, and more preferably 4300 [Pa. s] or more, and preferably 14000 [Pa. s] or less, more preferably 13000 [Pa. s] below. If the value of E×t does not reach 3000 [Pa. s], it is difficult to suppress the tendency of the optical laminate to produce anti-winding, and if it exceeds 15000 [Pa. s], the optical layered body tends to be excessively curled into a bow with the optical film 60 side as the inner side (hereinafter also referred to as "positive curl"). Since the optical layered body is difficult to become a flat (flat) state, Thus, the optical layered body becomes difficult to handle.

The storage elastic modulus E of the first adhesive layer 31 at 30° C. can be adjusted by the type of adhesive or adhesive used to form the first adhesive layer 31 . The storage elastic modulus E of the first adhesive layer 31 at 30° C. is preferably 100 MPa or more, more preferably 1000 MPa or more, may be 1500 MPa or more, or may be 2000 MPa or more. In addition, the storage elastic modulus E of the first adhesive layer 31 at 30° C. is usually not more than 10000 MPa, more preferably not more than 8000 MPa, and more preferably not more than 5000 MPa.

The thickness t of the first adhesive layer 31 can be adjusted according to the storage elastic modulus E of the first adhesive layer 31 at 30°C, but it is preferably less than 15 μm, more preferably less than 10 μm, and more preferably less than 8 μm. , usually 2.5 μm or more, preferably 3 μm or more, and may be 3.5 μm or more.

The optical laminated body of this embodiment can be as shown in Fig. 6 (b), has optical film 60, second adhesive layer 32, first liquid crystal layer 12, first adhesive layer 31, second liquid crystal layer 22, and The optical laminated body 73 with the adhesive layer of the layer structure of the adhesive layer 33 can also be shown in Figure 6 (a) in the adhesive layer On the side opposite to the second liquid crystal layer 22 of the adhesive layer 33 of the optical laminated body 73, there is an optical laminated body 72 (optical laminated body) with an adhesive layer attached to the second peeling layer 53 of the adhesive layer 33 ). Also, the optical layered body of the present embodiment may have an optical film 60, a second adhesive layer 32, a first liquid crystal layer 12, a first adhesive layer 31, and a second liquid crystal layer in sequence as shown in FIG. 4 (a). Layer 22 and the optical laminate 70 (optical laminate) with the substrate layer of the second substrate layer 21 can also be peeled off from the optical laminate 70 with the substrate layer as shown in FIG. 4 (b). The optical laminated body 71 (optical laminated body) which peeled off the base material layer of the 2nd base material layer 21. Each of these optical laminates (hereinafter, these are also collectively referred to as "optical laminates") can be Suppresses the occurrence of curling, and can suppress the above-mentioned troubles that occur when bonding to an optical display element.

(Liquid crystal laminate)

The liquid crystal layered layer system of this embodiment can be used to manufacture an optical laminated body. As shown in FIG. 2, at least the first liquid crystal layer 12, the first adhesive layer 31, and the second liquid crystal layer 22 are sequentially laminated. By. The first liquid crystal layer 12 and the second liquid crystal layer 22 are cured layers of a polymerizable liquid crystal compound as described above, and the absolute value of the amount of curl is 20 mm or less. Also, the first adhesive layer 31 is an adhesive cured layer composed of a cured product of a curable adhesive as described above, and preferably satisfies the relationship of the above-mentioned formula (1). The description of the first liquid crystal layer 12 , the second liquid crystal layer 22 , and the first adhesive layer 31 is as described above, so the description thereof is omitted here.

The liquid crystal layered body of this embodiment, as shown in Fig. 2 (a), has a first substrate layer 11, a first liquid crystal layer 12, a first adhesive layer 31, a second liquid crystal layer 22, and a second liquid crystal layer. The liquid crystal laminated body 40 (liquid crystal laminated body) with double-sided base material layers of the layer structure of the base material layer 21 may also be an attached layer 11 peeled from the liquid crystal laminated body 40 with double-sided base material layers. Liquid crystal laminated body 41 (liquid crystal laminated body) of a single-sided substrate layer (FIG. 2(b)). The liquid crystal laminated body 41 with a single-sided substrate layer, as shown in Figure 2 (b), has a first liquid crystal layer 12, a first adhesive layer 31, a second liquid crystal layer 22, and a second substrate layer 21. layer structure. By using each of these liquid crystal laminates (hereinafter, these are also collectively referred to as "liquid crystal laminates") to produce an optical laminate, the occurrence of curl can be suppressed, and it is possible to suppress the occurrence of warping when bonding to an optical display element. The above-mentioned unfavorable situation arises.

(Manufacturing method of liquid crystal laminated body and manufacturing method of optical laminated body)

Hereinafter, the manufacturing method of the liquid crystal laminated body and the manufacturing method of the optical laminated body of this embodiment are demonstrated based on FIGS. 1-6. In the manufacturing method of the optical layered body, for example, the liquid crystal layered body 41 with a single-side substrate layer can be used to manufacture the optical layered body. Hereinafter, in the optical layered body 73 with an adhesive layer shown in FIG. 6( b ), the second adhesive layer 32 is described as an example of an adhesive layer formed of an adhesive.

(Manufacturing method of liquid crystal laminated body)

The manufacturing method of the liquid crystal laminated body 41 with a single-sided base material layer shown in FIG. 2 (b) includes preparing the first liquid crystal layer 10 with a base material layer shown in FIG. 1 (a), and the first liquid crystal layer 10 with a base material layer. Steps of attaching the second liquid crystal layer 20 of the substrate layer shown in Figure 1 (b). The first liquid crystal layer 10 with a substrate layer has a first substrate layer 11 and a first liquid crystal layer 12 formed by polymerizing a polymerizable liquid crystal compound on the first substrate layer 11. The first substrate layer 11 The system is formed to be peelable from the first liquid crystal layer 12 . The second liquid crystal layer 20 with the base material layer has a second base material layer 21 and a second liquid crystal layer 22 formed by polymerizing a polymerizable liquid crystal compound on the second base material layer 21. The second base material layer 21 The system is formed to be peelable from the second liquid crystal layer 22 .

The step of preparing the first liquid crystal layer 10 with a substrate layer may include the following steps: coating a composition for forming a liquid crystal layer containing a polymerizable liquid crystal compound on the first substrate layer 11 and drying it; Waiting for active energy rays to polymerize and harden the polymerizable liquid crystal compound to form the first liquid crystal layer 12 . Similarly, the step of preparing the second liquid crystal layer 20 with a substrate layer may include the following steps: on the second substrate layer 21, coating a composition for forming a liquid crystal layer containing a polymerizable liquid crystal compound and It is dried and irradiated with active energy rays such as ultraviolet rays to polymerize and harden the polymerizable liquid crystal compound to form the second liquid crystal layer 22 .

Next, carry out the following steps: on the surface of the second liquid crystal layer 22 side of the second liquid crystal layer 20 attached to the substrate layer, an adhesive containing an adhesive composition for forming the first adhesive layer 31 of the adhesive hardened layer is formed The step of composition layer 31a. Through this step, the second liquid crystal layer 25 with a composition layer can be obtained (Fig. 1(c)). The second liquid crystal layer 25 with a composition layer, as shown in FIG. 1 (c), is the one in which the adhesive composition layer 31a, the second liquid crystal layer 22, and the second substrate layer 21 are sequentially laminated. The step of forming the adhesive composition layer 31a may include the following steps: a step of coating the adhesive composition on the surface of the second liquid crystal layer 22 side of the second liquid crystal layer 20 attached to the substrate layer.

After the obtained adhesive composition layer 31a side of the second liquid crystal layer 25 with the composition layer is laminated on the first liquid crystal layer 12 side of the first liquid crystal layer 10 with the substrate layer (Fig. 1 (d)), The first adhesive layer 31 is formed from the adhesive composition layer 31a to obtain a liquid crystal laminate 40 with substrate layers on both sides (FIG. 2(a)). The method of forming the adhesive composition layer 31a can be appropriately selected according to the type of the adhesive composition, and examples thereof include irradiation of active energy rays, heat treatment, and addition of a curing agent. The liquid crystal laminated body 40 with both substrate layers, as shown in Figure 2(a), is sequentially laminated with the first substrate layer 11, the first liquid crystal layer 12, the first adhesive layer 31, and the second liquid crystal layer. 22, and the second substrate layer 21.

From the liquid crystal laminated body 40 with both substrate layers as shown in Fig. 2 (a), the first substrate layer 11 is peeled off without peeling off the second substrate layer 21, thereby, as shown in Fig. 2 ( The base layer shown in b) includes the first liquid crystal layer 12 , the first adhesive layer 31 , the second liquid crystal layer 22 , and the second base material layer 21 , the liquid crystal laminated body 41 with a single substrate layer attached. The first adhesive layer 31 in the liquid crystal laminated body 40 with both substrate layers shown in FIG. 2(a) and the liquid crystal laminated layered body 41 with a single substrate layer shown in FIG. 2(b) The adhesive cured layer, which is a cured product of a curable adhesive, preferably has rigidity satisfying the relationship of the above formula (1). again, The absolute value of the curl amount of either the first liquid crystal layer 12 or the second liquid crystal layer 22 is 20 mm or less.

(Manufacturing method of optical laminate)

The manufacturing method of the optical laminated body 73 with the adhesive layer shown in Fig. 6 (b), at first, is to carry out the step of preparing the second adhesive layer 50 with the peeling layer: on the first peeling layer 51, form a The second adhesive layer 32 of the adhesive layer formed by the agent (Fig. 3 (a)). The step of preparing the second adhesive layer 50 with a release layer may also include the following steps: a step of applying an adhesive composition on the first release layer 51 and drying it to form the second adhesive layer 32 . Also, if necessary, a step of covering the surface of the second adhesive layer 32 opposite to the first release layer 51 with another release layer may be provided. Attach the second adhesive layer 32 of the prepared second adhesive layer 50 with the peeling layer to the optical film 60 (Fig. 3 (b)), and peel off the first peeling layer 51 to obtain the second adhesive layer with the second adhesive layer. Optical film 61 (FIG. 3(c)). The optical film 61 with the second adhesive layer, as shown in FIG. 3 (c), is the one in which the optical film 60 and the second adhesive layer 32 are laminated.

Afterwards, the second adhesive layer 32 of the optical film 61 with the second adhesive layer attached, and the liquid crystal laminated body 41 with a single substrate layer exposed by peeling off the first substrate layer 11 (Fig. 2 (b) ))) the first liquid crystal layer 12 (the first exposed surface) is pasted together to obtain an optical laminate 70 (optical laminate) with a substrate layer (Fig. 4 (a)). The liquid crystal laminated body 41 with a single base material layer is sufficient as long as it has the structure shown in FIG. The optical laminated body 70 with the substrate layer, as shown in Fig. 4 (a), is sequentially laminated with the optical film 60, the second adhesive layer 32, the first liquid crystal layer 12, the first adhesive layer 31, the second liquid crystal layer 22, and the second substrate layer 21. By peeling the second base layer 21 from the optical layered body 70 with a base layer, an optical layered body 71 peeled from the base layer can be obtained ( FIG. 4( b )).

Next, the step of preparing the adhesive layer 58 with the peeling layer in which the second peeling layer 53 and the adhesive layer 33 are laminated is performed (FIG. 5). The step of preparing the adhesive layer 58 with a release layer may also include the following steps: on the second release layer 53, apply an adhesive composition and dry it to form an adhesive layer 33 steps. Also, if necessary, a step of covering the surface of the adhesive layer 33 opposite to the second release layer 53 with another release layer may be provided.

The adhesive layer 33 side of the adhesive layer 58 with the prepared peeling layer and the second liquid crystal layer 22 (the second liquid crystal layer 22 (the second substrate layer) of the optical laminate 71 exposed by peeling the second substrate layer 21 The two exposed surfaces) are bonded together to obtain an optical laminate 72 with a release layer (Fig. 6 (a)). The optical laminated body 72 with peeling layer, as shown in Figure 6 (a), is sequentially laminated with an optical film 60, a second bonding layer 32, a first liquid crystal layer 12, a first bonding layer 31, and a second liquid crystal layer 22. The adhesive layer 33 and the second release layer 53. By peeling the second peeling layer 53 from the optical layered body 72 with a peeling layer, the optical layered body 73 with an adhesive layer shown in FIG. 6( b ) can be obtained. The obtained optical laminated body 73 with the adhesive layer attached can be bonded with the adhesive layer 33 and the optical display element to form an image display panel.

The manufacturing method of the above-mentioned liquid crystal laminated body (Fig. 2) and the manufacturing method of the optical laminated body (Fig. 4 and Fig. 6) are polymerized on the first substrate layer 11 or the second substrate layer 21 The liquid crystal compound hardens it to form the first liquid crystal layer 12 or the second liquid crystal layer 22 . Therefore, it is considered that when the first base material layer 11 is peeled off from the liquid crystal laminated body 40 with both base material layers shown in FIG. When the optical layered body 70 is peeled off from the second base material layer 21, the shrinkage stress remaining in the first liquid crystal layer 12 or the second liquid crystal layer 22 generated when the polymerizable liquid crystal compound is polymerized and cured is released. In this embodiment, since the absolute value of the curling amount of the first liquid crystal layer 12 and the second liquid crystal layer 22 is 20 mm or less, even if the shrinkage stress is relieved by peeling off the first base material layer 11 or the second base material layer 21, It is estimated that the amount of deformation of the first liquid crystal layer 12 and the second liquid crystal layer 22 is small. Therefore, even if the shrinkage stress of the first liquid crystal layer 12 and the second liquid crystal layer 22 is released, the optical laminate 71 ( FIG. 4( b )) peeled off from the substrate layer is not easily deformed. Thereby, the optical laminated body 71 peeled through the substrate layer, or the optical laminated body 72 with the peeling layer shown in Fig. 6 (a) and (b) or the optical laminated body 73 with the adhesive layer can be Suppresses the occurrence of rollback.

Also, since the first adhesive layer 31 is an adhesive hardened layer and has the rigidity of the above-mentioned formula (1), the optical laminate 71 peeled off from the substrate layer, the optical laminate 72 with a peeling layer, and the The optical layered body 73 of the adhesive layer can prevent the positive curl from becoming too much, making it difficult for the optical layered body to be in a flat (flat) state.

In addition, in this embodiment, the first liquid crystal layer 10 with a base material layer, the second liquid crystal layer 20 with a base material layer, and the second adhesive layer with a peeling layer used in the manufacture of liquid crystal laminates or optical laminates are Layer 50, adhesive agent layer 58 with peeling layer, optical film 60, optical film 61 with second adhesive layer and other membranous objects are all preferably long-sized membranous objects, and it is preferable to make this equal to continuous The steps are carried out under handling. The width direction W is usually a direction (TD direction) perpendicular to the longitudinal direction (transportation direction, MD direction) of the film.

(Modification)

The liquid crystal layered body, the optical layered body, and the manufacturing method thereof of the present embodiment can also be changed into modified examples as shown below. In addition, the above-mentioned embodiment and the modified examples shown below can also be combined arbitrarily.

(Modification 1)

In the above, although the case where the 2nd adhesive layer 32 which an optical laminated body has is an adhesive agent layer was demonstrated, it is not limited to this. For example, the second adhesive layer 32 may also be an adhesive cured layer made of cured adhesive. In this case, the second adhesive layer is not formed on the first peeling layer 51, but on the optical film 60 and the first base layer 11 of the liquid crystal laminate 41 with a single-side base layer is peeled off to expose On at least one of the first liquid crystal layer 12 (first exposed surface), an adhesive composition layer containing an adhesive composition may be formed.

(Modification 2)

In the above, the following situation is taken as an example for illustration: the second liquid crystal layer with the adhesive composition layer 31a provided on the second liquid crystal layer 22 side of the second liquid crystal layer 20 with the base material layer 25 (Fig. 1 (c)), the first liquid crystal layer 12 of the first liquid crystal layer 10 attached to the substrate layer is laminated on the adhesive composition layer 31a, but as long as the first liquid crystal layer attached to the substrate layer can be obtained The first liquid crystal layer 12 of the layer 10, the second liquid crystal layer 22 of the second liquid crystal layer 20 with the base material layer, and the liquid crystal laminated body 40 with both sides of the base material layer laminated through the first adhesive layer 31 (the second Figure 2 (a)) is not limited to this. For example, an adhesive composition layer 31a may be provided on the first liquid crystal layer 12 side of the first liquid crystal layer with a base layer 10, and the second liquid crystal layer 20 with a base layer may be laminated on the adhesive composition layer 31a. After the second liquid crystal layer 22 side, the adhesive composition layer 31a is cured to form the first adhesive layer 31 . In addition, both of the first liquid crystal layer 12 side of the first liquid crystal layer 10 with a base layer and the second liquid crystal layer 22 side of the second liquid crystal layer 20 with a base layer may be used to form an adhesive composition layer. 31a.

(Modification 3)

In the above, the following situation is taken as an example for illustration: using the second adhesive layer 50 with a peeling layer shown in FIG. The optical film 61 (Figure 3 (c)), the second adhesive layer 32 of the optical film 61 with the second adhesive layer attached, and the first liquid crystal layer 12 of the liquid crystal laminated body 41 with a single-sided substrate layer Bonding, but as long as it can be laminated via the second adhesive layer 32 on the exposed surface (first liquid crystal layer 12) of the liquid crystal laminated body 41 with a single-sided base layer exposed by peeling off the first base layer 11 The optical film 60 is sufficient, and is not limited thereto. For example, it is also possible to use the second adhesive layer 50 with a release layer shown in Fig. 3 (a) to be prepared on the exposed surface (first liquid crystal layer 12) of the liquid crystal laminate 41 with a single-sided substrate layer. The liquid crystal laminate with the second adhesive layer 32 is provided, and the optical film 60 is laminated on the second adhesive layer 32 . In this case, the liquid crystal laminate with the second adhesive layer only needs to The second bonding layer 32, the first liquid crystal layer 12, the first bonding layer 31, the second liquid crystal layer 22, and the second substrate layer 21 are all that is required in order, and between the second bonding layer 32 and the first liquid crystal layer 12 The surface on the opposite side may also have a first peeling layer 51 .

Although the above described the embodiments of the present invention and their modifications, the present invention is not limited to these embodiments and their modifications. For example, the steps of the above-mentioned embodiments and their modifications can also be implemented in combination. . Each member used in the embodiment will be described in detail below.

(optical film)

The optical film is a film including a thermoplastic resin film made of thermoplastic resin, which is a film with optical functions, for example, a polarizer, a polarizer with a protective layer formed on at least one side of the polarizer, a polarizer on the polarizer Polarizing plate with protective film, reflective film, semi-transmissive reflective film, brightness enhancement film, optical compensation film, film with anti-glare function, etc., with at least one layer of protective film. The optical film may be an optical film having a one-layer structure or a multi-layer structure of two or more layers.

It is presumed that the smaller the thickness or rigidity of the optical film contained in the optical layered body, the smaller the thickness or rigidity of the optical layered body is, the more likely it is affected by the release of the shrinkage stress caused by the liquid crystal layer. Also, the greater the thickness or rigidity of the base layer, the greater the shrinkage stress remaining in the liquid crystal layer, so it is presumed that it is more easily affected by the shrinkage stress released when the base layer is peeled off. Therefore, the thickness of the optical film is preferably not less than 2 μm and not more than 500 μm . The thickness of the optical film may be 10 μm or more, or 350 μm or less, or 200 μm or less, or 150 μm or less.

(polarizer)

Any suitable polarizer can be used as the polarizer. The term "polarizer" in this specification refers to a linear polarizer having the property of transmitting linearly polarized light having a vibration plane perpendicular to the absorption axis when non-polarized light is incident. For example, the resin film forming the polarizer may be a single-layer resin film or two or more layers. The laminated film. The polarizer may be a cured film in which a polymerizable liquid crystal compound is aligned to a dichroic dye and the polymerizable liquid crystal compound is polymerized.

Specific examples of polarizers composed of a single-layer resin film include polyvinyl alcohol (hereinafter referred to as "PVA") film, partially acetalized PVA film, vinyl. Ethyl acetate copolymer is a hydrophilic polymer film such as a partially acetalized film, which is dyed and stretched with dichroic substances such as iodine or dichroic dyes; dehydration treatment of PVA or polyvinyl chloride Dehydrochlorination acid-treated products such as polyolefin alignment films, etc. Since the optical properties are excellent, it is preferable to use a polarizer obtained by uniaxially stretching a PVA film dyed with iodine.

Specific examples of polarizers composed of a single-layer resin film include polyvinyl alcohol (hereinafter referred to as "PVA") film, partially acetalized PVA film, vinyl. Ethyl acetate copolymer is a hydrophilic polymer film such as a partially acetalized film, which is dyed and stretched with dichroic substances such as iodine or dichroic dyes; dehydration treatment of PVA or polyvinyl chloride Dehydrochlorination acid-treated products such as polyolefin alignment films, etc. Since the optical properties are excellent, it is preferable to use a polarizer obtained by uniaxially stretching a PVA film dyed with iodine.

The degree of saponification of the polyvinyl alcohol-based resin is usually about 85 to 100 mole%, preferably more than 98 mole%. Polyvinyl alcohol-based resins can also be modified, for example, polyvinyl formaldehyde or polyvinyl acetal modified with aldehydes can also be used. The 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 degree of saponification of the polyvinyl alcohol-based resin is usually about 85 to 100 mole%, preferably more than 98 mole%. Polyvinyl alcohol-based resins can also be modified, for example, polyvinyl formaldehyde or polyvinyl acetal modified with aldehydes can also be used. The degree of polymerization of the polyvinyl alcohol-based resin is usually about 1,000 to 10,000, preferably about 1,500 to 5,000.

Other manufacturing methods of polarizers include, for example, the following steps: First, prepare a substrate film, coat a solution of a resin such as polyvinyl alcohol-based resin on the substrate film, remove the solvent, and dry the substrate film. The step of forming a resin layer on top. In addition, a primer layer may be formed in advance on the surface of the base film on which the resin layer is formed. As the base film, resin films such as PET can be used. The material of the primer layer may, for example, be a resin used in a polarizer to cross-link a hydrophilic resin.

Next, adjust the amount of solvent such as moisture in the resin layer as necessary, then uniaxially stretch the base film and the resin layer, and then dye the resin layer with a dichroic dye such as iodine to allow the dichroic dye to be adsorbed and aligned. in the resin layer. Next, if necessary, the resin layer on which the dichroic dye is adsorbed and aligned is treated with a boric acid aqueous solution, and then a washing step of washing the boric acid aqueous solution is performed. Thereby, the resin layer in which the dichroic dye was adsorbed and aligned, that is, the film of the polarizer was manufactured. A well-known method can be used for each step.

The uniaxial stretching of the base film and the resin layer can be carried out before dyeing, during dyeing, during boric acid treatment after dyeing, or in multiple stages of these. The base film and resin layer can be uniaxially stretched in the MD direction (film conveyance direction). In this case, it can be uniaxially stretched between rollers with different peripheral speeds, or can be uniaxially stretched using a heated roller. stretch. In addition, the base film and the resin layer can be uniaxially stretched in the TD direction (direction perpendicular to the film conveyance direction), and in this case, a so-called tenter method (Tenter method) can also be used. In addition, the stretching of the base film and the resin layer may be a dry stretching in which the stretching is performed in the air, or a wet stretching in which the resin layer is stretched in a swollen state with a solvent. In order to exert the performance of the polarizer, the stretching ratio is at least 4 times, preferably at least 5 times, and most preferably at least 5.5 times. The upper limit of the draw ratio is not particularly limited, but is preferably 8 times or less from the viewpoint of suppressing cracking and the like.

The polarizer produced by the above method can be produced by peeling off the base film after laminating the protective layer described later. By this method, the polarizer can be further thinned.

The method for producing a polarizer of a cured film formed by aligning a dichroic dye with a polymerizable liquid crystal compound to polymerize the polymerizable liquid crystal compound may be, for example, the following method: coating a base film containing a polymerizable liquid crystal compound and a dichroic The composition for forming a polarizer of a chromatic dye is a method of polymerizing a polymerizable liquid crystal compound while maintaining a liquid crystal state and curing it to form a polarizer. Therefore, the obtained polarizer exists in the state laminated|stacked on a base film, and the polarizer with a base film can also be used as an optical film. Alternatively, the base film can also be made into a polarizer with a base film that can be peeled off from the polarizer, and laminated on the liquid crystal laminate 41 with a single-sided base layer through the second adhesive layer 32, or laminated on After attaching the second adhesive layer 50 of the peeling layer, the base film is peeled off, and the polarizer is used as an optical film.

色素、花青色素、萘色素、偶氮色素、蒽醌色素等，其中，較佳為偶氮色素。偶氮色素，可舉例如單偶氮色素、雙偶氮色素、參偶氮色素、肆偶氮色素、二苯乙烯偶氮色素等，而更佳為雙偶氮色素、參偶氮色素。 As the dichroic dye, a dye having a property in which the absorbance in the long axis direction and the short axis direction of the molecule are different, for example, a dye having a maximum absorption wavelength (λ max) in the range of 300 to 700 nm can be used. Such dichroic dyes include, for example, acridine dyes,

Pigments, cyanine dyes, naphthalene dyes, azo dyes, anthraquinone dyes, and the like, among which azo dyes are preferred. Azo dyes include, for example, monoazo dyes, disazo dyes, para-azo dyes, tertiary azo dyes, and stilbene azo dyes, more preferably disazo dyes and para-azo dyes.

The composition for forming a polarizer may contain a solvent, a polymerization initiator such as a photopolymerization initiator, a photosensitizer, a polymerization inhibitor, and the like. For the polymerizable liquid crystal compound, dichroic dye, solvent, polymerization initiator, photosensitizer, polymerization inhibitor, etc. contained in the composition for forming a polarizer, known ones can be used, for example, JP 2017 can be used - Those exemplified in Publication No. 102479 and Japanese Patent Application Laid-Open No. 2017-83843. In addition, as the polymerizable compound, the same ones as those exemplified as the polymerizable liquid crystal compound used to prepare the first liquid crystal layer and the second liquid crystal layer described later can also be used. Regarding the method of forming a polarizer using the composition for forming polarizers, the methods exemplified in the above publications can also be used.

The thickness of the polarizer is preferably at least 2 μm , more preferably at least 3 μm . Also, the thickness of the above-mentioned polarizer is 25 μm or less, preferably 15 μm or less, more preferably 13 μm or less, even more preferably 7 μm or less. In addition, the above-mentioned upper limit and lower limit may be combined arbitrarily. The thinner the thickness of the polarizer, the smaller the rigidity, and the easier it is to be affected by the shrinkage stress of the first liquid crystal layer or the second liquid crystal layer. Therefore, when using a polarizer with a small thickness as an optical film, it is better to use a polarizer with the above-mentioned curl. The absolute value of the first liquid crystal layer and the second liquid crystal layer, and the first adhesive layer is an adhesive hardening layer.

(polarizer)

A polarizing plate can be made by introducing a well-known adhesive layer on one or both sides of the polarizing plate or by laminating a protective layer. This polarizing plate is a so-called linear polarizing plate. The protective layer that can be laminated on one or both sides of the polarizer, for example, can be formed by using a thermoplastic resin film with excellent transparency, mechanical strength, thermal stability, moisture barrier, isotropy, and extensibility. Specific examples of such thermoplastic resins include cellulose resins such as cellulose triacetate; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polyether resins; polyethylene resins; Polycarbonate resin; polyamide resin such as nylon or aromatic polyamide resin; polyimide resin; polyethylene, polypropylene, ethylene. Polyolefin resins such as propylene copolymers; ring-system and cyclic polyolefin resins with norcamphene structure (also known as norcamphene-based resins); (meth)acrylic resins; polyarylate resins; polystyrene resins; Polyvinyl alcohol resins, and mixtures thereof. When there are protective films on both sides of the polarizer, the resin compositions of the two protective layers may be the same or different. In addition, in this specification, "(meth)acrylic acid" means either acrylic acid or methacrylic acid. "(meth)" in (meth)acrylate etc. has the same meaning.

The film formed of thermoplastic resin can be surface treated (for example, corona treatment, etc.) in order to improve the adhesion with the polarizer composed of PVA resin and dichroic material, and can also form a primer layer (Also known as undercoat) and so on.

The moisture permeability of the protective layer at a temperature of 40°C and a humidity of 90%RH is preferably 1 to 1500g/m ² . 24hr. If the moisture permeability of the protective layer exceeds 1500g/m ² . 24hr, in a high temperature environment, the polarizing plate is prone to curling changes over time. The lower the moisture permeability of the protective layer, the easier it is to obtain the effect of suppressing the temporal change of the curl of the polarizing plate. The moisture permeability of the protective layer at a temperature of 40°C and a humidity of 90%RH is more preferably 1000g/m ² . Below 24hr, more preferably 100g/m ² . Below 24hr, more preferably 10g/m ² . Below 24 hours. The moisture permeability can be measured in accordance with JIS Z 0208:1976.

Furthermore, in a polarizing plate used as an optical film, in order to reduce the influence of shrinkage stress of the first liquid crystal layer or the second liquid crystal layer, it is preferable to increase the rigidity of the protective layer laminated on the polarizing plate. Here, the so-called rigidity is defined as the product of the tensile modulus of the film used for the protective layer at a temperature of 23°C (hereinafter also referred to as "23°C elastic modulus") multiplied by the film thickness. For example, using a protective layer of a cellulose-based polymer represented by cellulose triacetate, the elastic modulus at 23°C is preferably in the range of 3000 to 5000 MPa, and using an acrylic polymer represented by polymethyl methacrylate For the protective layer, the elastic modulus at 23°C is preferably in the range of 2000 to 4000MPa. For the protective layer using a cycloolefin polymer with a norbornene structure, the elastic modulus at 23°C is preferably in the range of 2000 to 4000MPa. For the outer protective layer, it is preferable to use an acrylic polymer or a polyolefin polymer, and it is particularly preferable to use a cycloolefin polymer from the above-mentioned viewpoints of moisture permeability and rigidity. The modulus of elasticity at 23°C can be measured in accordance with JIS K 7113.

The protective layer may be, for example, stretched thermoplastic resin as described above, or may be unstretched (hereinafter also referred to as "unstretched resin"). Stretching treatment includes, for example, uniaxial stretching or biaxial stretching.

The stretching direction of the stretching treatment may be the longitudinal direction of the unstretched resin, may be a direction perpendicular to the longitudinal direction, or may be a direction oblique to the longitudinal direction. In the case of uniaxial stretching, the unstretched resin can be stretched in any one of these directions. Biaxial stretching may be simultaneous biaxial stretching in two stretching directions among these directions, or sequential biaxial stretching in other directions after stretching in a predetermined direction.

Stretching can be performed, for example, by stretching in the longitudinal direction using two or more pairs of rollers whose peripheral speed increases on the downstream side, or by clamping both ends of the unstretched resin in the longitudinal direction. Orthogonal direction stretching, etc. At this time, by adjusting the thickness of the stretched thermoplastic resin or adjusting the stretching ratio, the desired retardation value and wavelength dispersion can be suppressed.

The stretched thermoplastic resin preferably satisfies the following formula.

(1) 80nm≦Re(590)≦180nm

(2) 0.5<Rth(590)/Re(590)<0.8

(3) 0.85≦Re(450)/Re(550)<1.00

In the formula, Re(590), Re(450), and Re(550) represent the in-plane retardation values at the measurement wavelength of 590nm, 450nm, and 550nm, respectively, and Rth(590) represents the thickness direction phase at the measurement wavelength of 590nm difference. These in-plane retardation values and thickness direction retardation values refer to the values measured in an environment with a temperature of 23°C and a relative humidity of 55%.

When the refractive index in the direction of the in-plane slow axis is nx, the refractive index in the direction of the in-plane fast axis (direction perpendicular to the direction of the in-plane slow axis) is ny, the refractive index in the thickness direction is nz, and the thermoplastic resin after stretching When the thickness is d, the in-plane retardation value Re and the thickness direction retardation value Rth are defined by the following formula (S1) and formula (S2).

(S1) Re=(nx-ny)×d

(S2) Rth=[{(nx+ny)/2}-nz]×d

The above outer protective layer is preferably a stretched thermoplastic resin satisfying the above formulas (1) to (3). Also, the above-mentioned outer protective layer is preferably attached to a polarizer that has a slow axis in an oblique direction to the absorption axis of the polarizer, for example, so that the angle of the slow axis of the outer protective layer is relative to the absorption axis of the polarizer In the way of 45±10° or 135±10°, attach the outer protective layer and polarizer. By making the angle of the slow axis the above range, there will be a difference between the phase of light in the fast axis direction and the phase of light in the slow axis direction. If the optical layered body of this embodiment is used in an optical display element, the light emitted through the optical layered body can be become circularly polarized. Therefore, when the optical layered body of this embodiment is used in a display device of an optical display element, the display device has excellent visibility even when a displayed image or the like is viewed through polarized sunglasses.

The thickness of the protective layer is preferably at least 3 μm , more preferably at least 5 μm . Also, the thickness of the protective layer is preferably at most 50 μm , more preferably at most 30 μm . In addition, the above-mentioned upper limit and lower limit may be combined arbitrarily. The thinner the thickness of the polarizing plate, the less rigid it is, and the easier it is to be affected by the shrinkage stress of the first liquid crystal layer or the second liquid crystal layer. Therefore, when using a polarizing plate with a small thickness as an optical film, it is better to use a polarizing plate with the above-mentioned curl. The absolute value of the first liquid crystal layer and the second liquid crystal layer, and the first adhesive layer is an adhesive hardening layer.

The surface of the protective layer opposite to the polarizer may also have a surface treatment layer, for example, a hard coat layer, an anti-reflection layer, an anti-sticking layer, an anti-glare layer, a diffusion layer, and the like. The surface treatment layer may be another layer laminated on the protective layer, or may be formed by applying surface treatment to the surface of the protective layer.

The purpose of the hard coat layer is to prevent damage to the surface of the polarizing plate. For example, a cured film with excellent hardness and lubricating properties caused by ultraviolet curable resins such as acrylic and polysiloxane can be added to the surface of the protective layer. Wait to form. The purpose of the anti-reflection layer is to prevent the reflection of external light on the surface of the polarizer, which can be achieved by forming an anti-reflection film based on conventional methods. Also, the purpose of the anti-adhesion layer is to prevent adhesion with adjacent layers.

The purpose of the anti-glare layer is to prevent the reflection of external light on the surface of the polarizing plate and hinder the visual recognition of the transmitted light of the polarizing plate. , to form a concave-convex structure on the surface of the protective layer. The transparent microparticles used to impart a fine uneven structure on the surface of the protective layer include, for example, silicon oxide, aluminum oxide, titanium oxide, zirconium oxide, tin oxide, indium oxide, cadmium oxide, Inorganic fine particles such as antimony oxide that may be conductive, organic fine particles such as cross-linked or uncross-linked polymers, and other fine particles. The content of the transparent fine particles is generally 2 to 50 parts by mass, preferably 5 to 25 parts by mass, based on 100 parts by mass of the resin forming the layer forming the fine uneven structure. The anti-glare layer may also serve as a diffusion layer (viewing angle widening function, etc.) for diffusing the transmitted light of the polarizing plate to expand the viewing angle, etc.

When the surface treatment layer is another layer laminated on the protective layer of the polarizing plate, the thickness of the surface treatment layer is preferably 0.5 μm or more, more preferably 1 μm or more. Also, it is preferably 10 μm or less, more preferably 8 μm or less. When the thickness is less than 0.5 μm , it tends to be difficult to effectively prevent damage to the surface of the polarizing plate. Also, if the thickness exceeds 10 μm , it will become difficult to suppress the curling of the polarizing plate due to, for example, increased cure shrinkage.

When the thickness of the polarizing plate is not less than 2 μm and not more than 300 μm , the optical layered body and its manufacturing method of the above-mentioned embodiment are preferable. The thickness of the polarizing plate may be 10 μm or more, or 150 μm or less, 120 μm or less, or 80 μm or less.

(Polarizer with protective film)

Polarizing plates are usually made into polarizing plates with poly-protective films by virtue of their single-layer protective film. The protective film includes a resin film for a protective film, and an adhesive layer for a protective film laminated thereon. The thickness of the protective film may be, for example, 30 to 200 μm , preferably 40 to 150 μm , more preferably 50 to 120 μm .

The resin constituting the resin film for protective film may be, for example, polyolefin-based resins such as polyethylene-based resins and polypropylene-based resins; cyclic polyolefin-based resins; polyethylene terephthalate or polyethylene naphthalate, etc. Polyester resins; polycarbonate resins; (meth)acrylic resins, etc. Among them, polyester-based resins such as polyethylene terephthalate are preferable. The resin film for protective films may have a one-layer structure, or may have a multi-layer structure of two or more layers.

As the adhesive constituting the adhesive layer for a protective film, the same adhesive as that constituting the adhesive layer described later can be used. In addition, the protective film can be formed by forming an adhesive layer by applying an adhesive composition on the surface of the resin film for a protective film and drying it. If necessary, in order to improve the adhesiveness of the adhesive coating surface of the resin film for protective film, surface treatment (for example, corona treatment) can be applied, and a thin layer such as a primer layer (also called primer layer) can also be formed. layer. Moreover, if necessary, you may have the peeling layer for covering the surface of the adhesive agent layer for protective films opposite to the resin film side for protective films. This release layer can be peeled off at an appropriate timing when bonding to a polarizing plate.

In the production process of the polarizing plate with protective film attached to the polarizing plate, positive curl can also be given in the longitudinal direction of the polarizing plate with protective film by giving a difference in tension or a difference in peripheral speed. Therefore, in the optical layered body and the manufacturing method of the optical layered body of the above-mentioned embodiment, when the polarizing plate with a protective film is used as the optical film, the polarizing plate with a protective film Imparting positive curl can be expected to suppress the curling of the optical layered body more easily.

In the case where the optical film 60 in the above embodiment is a polarizing plate with a protective film, when the thickness of the polarizing plate with a protective film is 32 μm or more and 500 μm or less, the optical laminate of the above embodiment and its production method is better. The thickness of the polarizing plate with a protective film may be 40 μm or more, and may be 350 μm or less, 200 μm or less, or 150 μm or less.

(adhesive layer)

The adhesive layer refers to a layer composed of an adhesive. In this specification, the term "adhesive" refers to one that exhibits adhesiveness by affixing itself to an adherend such as an optical film or a liquid crystal layer, and is called a pressure-sensitive adhesive. In addition, in the active energy ray-curable adhesive described later, the degree of crosslinking and adhesive force can be adjusted by irradiating energy rays. As mentioned above, the second adhesive layer can also be an adhesive layer.

Adhesives that are conventionally known and have excellent optical transparency can be used without particular limitation. As the adhesive, for example, an adhesive having a base polymer such as acrylic, urethane, silicone, or polyvinyl ether can be used. In addition, active energy ray-curable adhesives, thermosetting adhesives, and the like may be used. Among them, an acrylic resin excellent in transparency, adhesive force, re-peelability (hereinafter also referred to as remanufacturability), weather resistance, heat resistance, etc. is preferable as an adhesive agent for the matrix polymer. The adhesive layer is preferably composed of a reaction product of an adhesive composition containing (meth)acrylic resin (1), crosslinking agent (2), and silane compound (3), and may also contain other components ( 4).

((meth)acrylic resin (1))

The (meth)acrylic resin (1) contained in the adhesive composition is preferably a structural unit derived from an alkyl (meth)acrylate represented by the following formula (I) (hereinafter also referred to as "Structural unit (I)") is a polymer (hereinafter also referred to as "(meth)acrylate polymer") whose main component (for example, contains 50% or more of these). The term "derived from" in this specification means that the chemical structure is changed due to the polymerization of compounds such as alkyl (meth)acrylates.

[wherein, R ¹⁰ represents a hydrogen atom or a methyl group, R ²⁰ represents an alkyl group with 1 to 20 carbon atoms, the aforementioned alkyl group can have any structure of linear, branched or cyclic, the aforementioned alkyl group The hydrogen atom in may also be substituted with an alkoxy group having 1 to 10 carbons. ]

The (meth)acrylates represented by the formula (I) include, for example, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate , n-butyl (meth)acrylate, isobutyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, (meth)acrylic acid Isohexyl acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-(meth)acrylate And isononyl, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-dodecyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate , stearyl (meth)acrylate, tertiary butyl (meth)acrylate, etc. Specific examples of the alkoxy group-containing alkyl acrylate include 2-methoxyethyl (meth)acrylate, ethoxymethyl (meth)acrylate, and the like. Among them, it is preferable to contain n-butyl (meth)acrylate or 2-ethylhexyl (meth)acrylate, and it is particularly preferable to contain n-butyl (meth)acrylate.

The (meth)acrylate polymer may contain a structural unit derived from a monomer other than the structural unit (I). The structural units derived from other monomers may be one kind, or two or more kinds. Other monomers that may contain (meth)acrylate polymers include, for example, monomers with polar functional groups, monomers with aromatic groups, and acrylamide-based monomers.

The monomer having a polar functional group may, for example, be (meth)acrylate having a polar functional group. Polar functional groups, such as hydroxyl groups, carboxyl groups, substituted amino groups, unsubstituted amino groups, etc. can be combined. As a polar functional group, a heterocyclic group, such as an epoxy group, etc. are also mentioned, for example.

The content of the structural unit derived from a monomer having a polar functional group in the (meth)acrylate polymer is preferably 20 parts by mass or less with respect to 100 parts by mass of the total structural units of the (meth)acrylate polymer , more preferably from 0.1 to 20 parts by mass, more preferably from 0.1 to 10 parts by mass, particularly preferably from 0.5 to 10 parts by mass.

Monomers with aromatic groups, for example, have one (meth)acryl group and more than one aromatic ring (such as benzene ring, naphthalene ring, etc.) in the molecule, and have phenyl, phenoxyethyl , or benzyl (meth)acrylate.

Structural units derived from monomers with aromatic groups in (meth)acrylate polymers The content of the bit is preferably 50 parts by mass or less, more preferably 4 parts by mass or more and 50 parts by mass or less, and more preferably 4 parts by mass or more with respect to 100 parts by mass of the total structural units of the (meth)acrylate polymer 25 parts by mass or less.

Acrylamide-based monomers, such as N-(methoxymethyl)acrylamide, N-(ethoxymethyl)acrylamide, N-(propoxymethyl)acrylamide, N -(butoxymethyl)acrylamide, N-(2-methylpropoxymethyl)acrylamide and the like. Bleeding out of additives such as an antistatic agent, which will be described later, can be suppressed by containing such structural units.

Furthermore, the structural units derived from monomers other than the structural unit (I) may include structural units derived from styrene-based monomers, structural units derived from vinylic monomers, and those derived from ( Structural units of meth)acryl monomers, etc.

The weight average molecular weight (hereinafter, also simply referred to as "Mw") of the (meth)acrylic resin (1) is preferably 500,000 to 2,500,000. If the weight average molecular weight is more than 500,000, the durability of the adhesive layer under high temperature and high humidity environment can be improved. If the weight average molecular weight is 2,500,000 or less, the handling property at the time of coating of the coating liquid containing the adhesive composition can be improved. The molecular weight distribution (Mw/Mn) represented by the ratio of the weight average molecular weight (Mw) to the number average molecular weight (hereinafter also simply referred to as "Mn") is usually 2 to 10. The "weight-average molecular weight" and "number-average molecular weight" in this specification refer to polystyrene-equivalent values measured by gel permeation chromatography (GPC).

(Meth)acrylic resin (1), when dissolved in ethyl acetate to make a solution with a concentration of 20% by mass, preferably has a viscosity of 20Pa at 25°C. s or less, more preferably 0.1 to 15Pa. s. When the viscosity at 25° C. of the (meth)acrylic resin (1) is within the above range, it contributes to reproducibility. The above-mentioned viscosity can be measured by a Brookfield viscometer (Brookfieid viscometer).

From the viewpoint of both adhesiveness and durability, the (meth)acrylic resin (1) The glass transition temperature is preferably -10°C to -60°C. In addition, the glass transition temperature can be measured by a differential scanning calorimeter (DSC).

The (meth)acrylic resin (1) may contain two or more kinds of (meth)acrylate polymers. Such (meth)acrylate polymers include, for example, those whose main component is the structural unit (I) derived from the above-mentioned (meth)acrylate, and have a relatively low molecular weight in the range of 50,000 to 300,000 in weight average molecular weight. (meth)acrylate polymers.

(crosslinking agent (2))

The adhesive composition forming the adhesive layer preferably contains a crosslinking agent (2). The cross-linking agent (2) can be, for example, a conventional cross-linking agent (for example, isocyanate compound, epoxy compound, aziridine compound, metal chelate, peroxide, etc.), especially the adhesive composition From the viewpoint of period and cross-linking speed, etc., isocyanate-based compounds are preferred.

The isocyanate-based compound is preferably a compound having at least two isocyanate groups (-NCO) in the molecule, such as aliphatic isocyanate-based compounds (such as hexamethylene diisocyanate, etc.), alicyclic isocyanate-based compounds ( For example, isophorone diisocyanate, etc.), hydrogenated xylene diisocyanate, hydrogenated diphenylmethane diisocyanate, aromatic isocyanate-based compounds (such as toluene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate , naphthalene diisocyanate, triphenylmethane triisocyanate, etc.), etc. In addition, the crosslinking agent (2) may be an adduct (adduct) with the polyol compound of the above-mentioned isocyanate compound [for example, an adduct from glycerin, trimethylolpropane, etc.], Polyurethane prepolymerization by addition reaction of isocyanate compound, diurea compound, polyether alcohol, polyester polyol, acrylic polyol, polybutadiene polyol, polyisoprene polyol, etc. Derivatives of isocyanate compounds and the like. The crosslinking agent (2) can be used individually or in combination of 2 or more types. Among them, from the viewpoint of durability, preferred are toluene diisocyanate, xylene diisocyanate, hexamethylene diisocyanate, and hexamethylene diisocyanate. Isocyanate and these polyol compounds or these isocyanate compounds.

The ratio of the crosslinking agent (2) is, for example, 0.01 to 10 parts by mass, preferably 0.1 to 3 parts by mass, more preferably 0.1 to 1 part by mass, relative to 100 parts by mass of the (meth)acrylic resin (1) . When it is below the above-mentioned upper limit, it is advantageous to the improvement of durability, and if it is more than the above-mentioned lower limit, the generation of gas can be suppressed, and it is advantageous for the improvement of remanufacturability.

(Silane compound (3))

The adhesive composition contains a silane compound (3). By containing the silane compound (3), the adhesiveness of the adhesive layer and the layer to be laminated can be improved. Two or more silane compounds (3) may also be used.

The silane compound (3) can be, for example, vinyltrimethoxysilane, vinyltriethoxysilane, vinylparaffin (2-methoxyethoxy)silane, 3-glycidoxypropyltrimethoxy Silane, 3-Glycidoxypropyltriethoxysilane, 3-Glycidoxypropylmethyldimethoxysilane, 3-Glycidoxypropylethoxydimethylsilane , 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryl Oxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, etc.

Moreover, the silane compound (3) may contain the oligomer derived from the said silane compound (3).

The content of the silane compound (3) in the adhesive composition is usually 0.01 to 10 parts by mass, preferably 0.03 to 5 parts by mass, more preferably 0.05 to 2 parts by mass, more preferably 0.1 to 1 part by mass. When content of a silane compound (3) is 0.01 mass part or more, it will become easy to improve the adhesiveness of an adhesive layer, an optical film, a liquid crystal layer, etc. to-be-adhered bodies. When the content is 10 parts by mass or less, bleeding of the silane compound (3) from the adhesive layer can be suppressed.

(other ingredients (4))

The adhesive composition forming the adhesive layer may contain one or more of the following additives as other components (4), for example, antistatic agents such as ionic compounds, solvents, crosslinking catalysts, viscosity-imparting agents, etc. Additives such as resins (tackifiers), plasticizers, weather-resistant stabilizers, softeners, dyes, pigments, inorganic fillers, and resins other than acrylic resins.

(active energy ray hardening adhesive)

It is also useful to compound an ultraviolet-curable compound such as polyfunctional acrylate in the adhesive composition, and then irradiate it with ultraviolet rays to harden the adhesive layer to make a harder adhesive layer, and it can be cured by active energy rays type adhesive. "Active energy ray-curing adhesive" has the property of being cured by irradiation with energy rays such as ultraviolet rays or electron beams. Since even the active energy ray-curable adhesive has adhesiveness before energy ray irradiation, it has an adherend that can be adhered to an optical film or a liquid crystal layer, and can adjust the density hardened by energy ray irradiation. Adhesives of a strong nature.

Active energy ray-curable adhesives generally contain an acrylic adhesive and an active energy ray polymerizable compound as main components. Usually, a crosslinking agent is added, or a photopolymerization initiator, a photosensitizer, etc. can be added as needed.

The storage elastic modulus of the adhesive layer is preferably 0.10 to 10.0 MPa at 23° C., more preferably 0.15 to 5.0 MPa. When the storage elastic modulus at 23° C. is 0.1 MPa or more, it is preferable to suppress defects such as peeling when temperature changes occur. Moreover, when it is 10.0 MPa or less, since the durability fall by the fall of adhesive force is hard to generate|occur|produce, it is preferable. In addition, the storage elastic modulus of the adhesive layer can be measured by the method described in the implementation.

The thickness of the adhesive layer is preferably at least 3 μm , more preferably at least 5 μm . Also, the thickness of the adhesive layer is preferably 40 μm or less, more preferably 30 μm or less. In addition, the above-mentioned upper limit and lower limit may be combined arbitrarily.

(adhesive hardening layer)

The adhesive cured layer refers to a layer formed by curing the curable components in the adhesive composition. The adhesive composition for forming the adhesive hardened layer is an adhesive other than a pressure-sensitive adhesive (adhesive), and examples thereof include water-based adhesives and active energy ray-curable adhesives. As the water-based adhesive, for example, a polyvinyl alcohol-based resin is dissolved or dispersed in water. The active energy ray-curable adhesive is, for example, a solvent-free active energy ray-curable adhesive containing a curable compound cured by irradiation with active energy rays such as ultraviolet rays, visible light, electron beams, and X-rays. Adhesion between layers can be improved by using a solvent-free active energy ray-curable adhesive. On the other hand, if the active energy ray-curable adhesive contains a solvent (especially an organic solvent), sufficient adhesion cannot be obtained even if the curable components contained in the adhesive are the same. When it becomes a predetermined size, it is easy to cause defects such as peeling at the end. Moreover, since an additional step of drying the solvent is required, an additional shrinkage stress is applied by heat, and there is a possibility that the optical layered body may be easily reversed.

When using a solvent-free active energy ray-curable adhesive containing a curable compound that is hardened by irradiation of active energy rays, the storage elastic modulus that indicates the hardness of the active energy ray-curable adhesive after curing The rigidity multiplied by the thickness is mostly higher than the rigidity of the water-based adhesive after hardening. In order to increase the rigidity of the adhesive cured layer provided between the first liquid crystal layer and the second liquid crystal layer, it is preferable to use a solvent-free active energy ray curable adhesive.

The active energy ray-curable adhesive is preferably either one or both of a cationic polymer-containing curable compound and a radically polymerizable curable compound because it exhibits good adhesiveness. The active energy ray-curable adhesive may further contain a cationic polymerization initiator or a radical polymerization initiator for initiating the curing reaction of the above-mentioned curable compound.

Cationically polymerizable hardening compounds, such as epoxy compounds (intramolecular A compound having 1 or more epoxy groups), or an oxetane-based compound (a compound having 1 or more oxetanes in a molecule), or a combination thereof.

Radical polymerizable curable compounds, such as (meth)acrylic compounds (compounds with one or more (meth)acryloxy groups in the molecule), free radical polymerizable bis Bonded other vinyl compounds, or a combination of these.

The active energy ray-curing adhesive may contain a sensitizer if necessary. By using a sensitizer, the reactivity can be improved, and the mechanical strength and adhesive strength of the adhesive layer can be further improved. Sensitizers can be used appropriately. When compounding a sensitizer, the compounding amount is preferably in the range of 0.1 to 20 parts by mass relative to 100 parts by mass of the total amount of the active energy ray-curable adhesive.

Active energy ray hardening adhesives may contain ion trapping agents, antioxidants, chain transfer agents, tackifiers, thermoplastic resins, fillers, flow regulators, plasticizers, defoamers, antistatic agents, Additives for leveling agents, solvents, etc.

The adhesive composition layer can also be formed by coating the adhesive composition on the bonding surface of the first liquid crystal layer attached to the substrate layer or the second liquid crystal layer attached to the substrate layer. Coating methods can be used using die coater, comma coater, reverse roll coater, gravure coater, bar coater, wire bar coater, knife coater, air General coating technology such as knife coater.

There is no particular limitation on the drying method when the water-based adhesive is used, for example, a drying method using a hot air dryer or an infrared dryer can be used.

When an active energy ray-curable adhesive is used, the adhesive composition layer can be cured by irradiating active energy rays such as ultraviolet rays, visible light, electron beams, and X-rays to form an adhesive cured layer. The active energy rays are preferably ultraviolet rays. In this case, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high pressure mercury lamps, chemical lamps, black light lamps, microwave-excited mercury lamps, and metal halide lamps can be used as light sources.

In the case of hardening the adhesive composition layer by ultraviolet irradiation, the intensity of ultraviolet light irradiation is determined by the composition of the adhesive composition, and is not particularly limited, but is preferably 10 to 1000 mW/cm ² , More preferably, it is 100 to 600 mW/cm ² . If the light irradiation intensity to the resin composition is less than 10mW/cm ² , the reaction time becomes too long, and if it exceeds 1000mW/cm ² , due to the heat radiated from the light source and the heat generated during the polymerization of the adhesive composition, The resulting hardened adhesive layer may be yellowed. Also, there is a possibility that a larger shrinkage stress may be generated by heat radiated from the light source. The irradiation intensity is the intensity in the wavelength region effective for the activation of the polymerization initiator, preferably the photocationic polymerization initiator, more preferably the intensity in the wavelength region below 400nm, and more preferably the intensity in the wavelength region Intensity in the wavelength region of 280 to 320 nm. Preferably, it is set to irradiate once or multiple times at such a light intensity that the accumulated light amount is 10 mJ/cm ² , preferably 100 to 1000 mJ/cm ² , more preferably 200 to 600 mJ/cm ² . If the cumulative light intensity on the adhesive composition is less than 10 mJ/cm ² , the generation of active species derived from the polymerization initiator will be insufficient, resulting in insufficient hardening of the adhesive composition layer. When the accumulated light quantity exceeds 1000 mJ/cm ² , the irradiation time becomes very long, which is not conducive to improvement of productivity. Also, there is a possibility that a larger shrinkage stress may be generated by heat radiated from the light source. Depending on the type of the first substrate layer, the second substrate layer, the first liquid crystal layer, the second liquid crystal layer, etc., or the combination of components in the adhesive composition, etc., the wavelength of light irradiation (UVA (320 to 390nm) ) or UVB (280 to 320nm)), the cumulative amount of light required according to the wavelength of light irradiation also changes.

The viscosity of the active energy ray-curable adhesive should be selected so that it can be applied by any coating method, and the viscosity at a temperature of 25°C should be between 10 and 1000mPa. The range of sec is good, more preferably 20 to 500mPa. The range of sec. When the viscosity is too small, it tends to be difficult to form a hardened adhesive layer of desired thickness. On the other hand, if the viscosity is too high, the active energy ray-curable adhesive tends to become difficult to flow during coating, and it tends to be difficult to obtain a uniform coating film without variation. The so-called viscosity here refers to the The value measured at 10rps after adjusting the temperature of the adhesive to 25°C with an E-type viscometer.

(Adhesive layer with release layer)

Adhesive layer with release layer (including the second adhesive layer with release layer using the adhesive layer as the second adhesive layer), for example, the adhesive composition can be coated on the release-treated surface of the release layer and used It is obtained by drying etc. to form an adhesive layer. The adhesive layer with a release layer may have another release layer for covering and protecting the surface of the adhesive layer opposite to the release layer side, if necessary. The peeling layer and other peeling layers can be peeled off at an appropriate timing.

(peeling layer)

The first peeling layer and the second peeling layer (hereinafter, these are also collectively referred to as "peeling layers") can be peeled from the adhesive layer, and have the ability to support the adhesive layer formed on the peeling layer to protect the adhesive layer. Function. As the release layer, a known release film or release paper can be used, but it may be, for example, a film formed of a resin material exemplified as a base material layer described later and subjected to release treatment such as silicone coating. For other peeling layers, the same material as the peeling layer can also be used.

The peeling layer can be peeled off from the adhesive layer, and the magnitude of the peeling force between the peeling layer and the adhesive layer must be determined in consideration of the order in which the peeling layers are peeled off. The above-mentioned peeling force is to prepare a test piece for measurement (200mm in length and 25mm in width) with an adhesive layer on the peeling layer, and stick it to glass of an appropriate size, using a high-pressure cooking kettle (AGS-50NX) manufactured by Shimadzu Corporation. The partially peeled peeling layer and the glass are respectively clamped in such a way as to form a peeling starting point, and the peeling strength measured when peeling the peeling layer toward the direction of 180° at a speed of 300mm/min can be regarded as the peeling force. The peeling force between the peeling layer and the adhesive layer is preferably 0.01 to 0.20N/25mm, more preferably 0.02 to 0.10N/25mm, and even more preferably 0.02 to 0.06N/25mm. If it is less than 0.01N/25mm, floating may occur between the release layer and the adhesive layer during transportation. Also, if it exceeds 0.20N/25mm, the adhesion between the peeling layer and the adhesive layer will be high, and the The peeling layer is difficult to peel off from the adhesive layer, so if the peeling layer is peeled off, the adhesive layer will be broken, so that the peeled peeling layer will be in a state where a part of the adhesive layer is attached, and the layer that does not want to be peeled off will be separated. There is a possibility of occurrence of peeling (for example, peeling between the layer bonded to the side opposite to the peeling layer of the adhesive layer and the adhesive layer).

(LCD layer)

The first liquid crystal layer and the second liquid crystal layer (hereinafter, both are also collectively referred to as "liquid crystal layer") are cured layers formed by polymerizing a polymerizable liquid crystal compound, and may also be retardation layers. The optical properties of the liquid crystal layer can be adjusted by the alignment state of the polymerizable liquid crystal compound.

In this specification, the alignment of the optical axis of the polymerizable liquid crystal compound to the plane of the substrate layer is defined as horizontal alignment, and the alignment of the optical axis of the polymerizable liquid crystal compound to the plane of the substrate layer is defined as vertical alignment. pairing. The so-called optical axis refers to the refractive index ellipsoid formed by the alignment of the polymerizable liquid crystal compound. The cross section cut in the direction perpendicular to the optical axis is the circular direction, that is, the refractive index of the two directions equal direction.

The polymerizable liquid crystal compound may, for example, be a rod-shaped polymerizable liquid crystal compound or a discotic polymerizable liquid crystal compound. When the rod-shaped polymerizable liquid crystal compound is aligned horizontally or vertically with respect to the substrate layer, the optical axis of the polymerizable liquid crystal compound is aligned with the long axis direction of the polymerizable liquid crystal compound. When the disc-shaped polymerizable liquid crystal compound is aligned, the optical axis of the polymerizable liquid crystal compound exists in the direction perpendicular to the disc surface of the polymerizable liquid crystal compound.

In order for the liquid crystal layer formed by polymerizing the polymerizable liquid crystal compound to exhibit an in-plane retardation, the polymerizable liquid crystal compound may be aligned in an appropriate direction. In the case where the polymerizable liquid crystal compound is rod-shaped, an in-plane retardation is exhibited by aligning the optical axis of the polymerizable liquid crystal compound to a level with respect to the plane of the substrate layer. At this time, the direction of the optical axis and the direction of the slow axis unanimous. Discs in polymerizable liquid crystal compounds In this case, the in-plane phase difference is exhibited by aligning the optical axis of the polymerizable liquid crystal compound to be horizontal with respect to the plane of the substrate layer, and at this time, the optical axis is perpendicular to the slow axis. The alignment state of the polymerizable liquid crystal compound can be adjusted through the combination of the alignment film and the polymerizable liquid crystal compound.

The polymerizable liquid crystal compound is a compound having a polymerizable group and liquid crystallinity. The term "polymerizable group" refers to a group involved in a polymerization reaction, preferably a photopolymerizable group. Here, the term "photopolymerizable group" refers to a group that can participate in a polymerization reaction by an active radical generated from a photopolymerization initiator described later, an acid, or the like. Examples of polymerizable groups include vinyl, vinyloxy, 1-chlorovinyl, isopropenyl, 4-vinylphenyl, acryloxy, methacryloxy, oxiranyl, and oxygen heterocycles. Butyl, etc. Among them, acryloxy, methacryloxy, ethyleneoxy, oxiranyl and oxetanyl are preferred, and acryloxy is more preferred. The liquid crystal properties of polymerizable liquid crystal compounds can be either thermotropic liquid crystals or meltotropic liquid crystals. If the thermotropic liquid crystals are classified in order, they can be nematic liquid crystals or smectic liquid crystals. .

As the rod-shaped polymerizable liquid crystal compound or the disc-shaped polymerizable liquid crystal compound, well-known ones can be used, such as Japanese Patent Application Laid-Open No. 2015-163937, Japanese Patent Laid-Open No. 2016-42185, International Publication No. 2016/158940, Those exemplified in Japanese Patent Application Laid-Open No. 2016-224128.

The liquid crystal layer may have a one-layer structure or a multi-layer structure of two or more layers. When having a multilayer structure of two or more layers, when preparing a liquid crystal layer with a base layer described later, it is sufficient to form a liquid crystal layer of a multilayer structure of two or more layers on the base layer. When the liquid crystal layer has a one-layer structure, the thickness of the liquid crystal layer is preferably more than 0.3 μm , or more than 1 μm , usually less than 10 μm , or less than 5 μm , more preferably less than 3 μm . When the liquid crystal layer is a multilayer structure of two or more layers, the thickness of the liquid crystal layer is preferably more than 0.5 μm , and can also be more than 1 μm , usually less than 10 μm , or less than 5 μm , more preferably 3 μm or less. The thickness of the liquid crystal layer is preferably 5 μm or less, more preferably 3 μm or less, from the viewpoint of contributing to the thinning of the polarizing plate as a whole and effectively suppressing curling.

(LC layer with substrate layer)

The first liquid crystal layer with a substrate layer and the second liquid crystal layer with a substrate layer (hereinafter, both are collectively referred to as "the liquid crystal layer with a substrate layer") can be prepared in the following manner. On the material layer, a composition for forming a liquid crystal layer containing a polymerizable liquid crystal compound is applied and dried to form a liquid crystal layer, which is a cured layer formed by polymerizing a polymerizable liquid crystal compound. The composition for forming a liquid crystal layer, when the alignment layer described later is formed on the substrate layer, it only needs to be coated on the alignment layer. The layer-forming composition and the like form a multilayer structure.

The composition for forming a liquid crystal layer usually contains a solvent in addition to the polymerizable liquid crystal compound. The composition for forming a liquid crystal layer may further contain a polymerization initiator, a reactive additive, a polymerization inhibitor, and the like. For solvents, polymerization initiators, reactive additives, polymerization inhibitors, etc., it can be used in JP-A-2015-163937, JP-A-2016-42185, International Publication No. 2016/158940, JP-A-2016- Those exemplified in Publication No. 224128.

Coating of the liquid crystal layer forming composition can be performed by spin coating, extrusion, gravure coating, die coating, slit coating, bar coating, spraying, etc. , flexographic printing and other well-known printing methods. After applying the composition for forming a liquid crystal layer, it is preferable to remove the solvent under conditions that do not polymerize the polymerizable liquid crystal compound contained in the applied layer. The drying method may, for example, be natural drying, ventilation drying, heat drying, or reduced-pressure drying.

The polymerization of the polymerizable liquid crystal compound performed after drying of the coating layer can be performed by a known method of polymerizing a compound having a polymerizable functional group. The polymerization method includes, for example, thermal polymerization or photopolymerization, and photopolymerization is preferable from the viewpoint of the ease of polymerization. When polymerizing a polymerizable liquid crystal compound by photopolymerization, it is preferable to use one containing a photopolymerization initiator as a composition for forming a liquid crystal layer, and to coat The composition for forming a liquid crystal layer is spread and dried, and the polymerizable liquid crystal compound contained in the dry film after drying is aligned to liquid crystal, and photopolymerization is carried out while maintaining the liquid crystal aligned state.

Photopolymerization can be performed by irradiating active energy rays to the liquid crystal-aligned polymerizable liquid crystal compound in the dry film. The active energy ray to be irradiated can be appropriately selected depending on the type and amount of polymerizable groups possessed by the polymerizable liquid crystal compound, the type of photopolymerization initiator, etc., and can be selected from visible light, ultraviolet rays, laser light, and X-rays, for example. , α-rays, β-rays and γ-rays constitute one or more active energy rays. Among them, from the viewpoint of being easy to control the progress of the polymerization reaction and being applicable to a wide range of users in this field as a photopolymerization device, ultraviolet rays are preferable, and it is preferable to select polymerizability in such a way that photopolymerization can be carried out by ultraviolet rays. Kind of liquid crystal compound or photopolymerization initiator. During photopolymerization, the film can be cooled and dried by appropriate cooling means, and the polymerization temperature can be controlled by irradiating active energy rays.

(substrate layer)

The first substrate layer and the second substrate layer (hereinafter, both are also collectively referred to as "substrate layer") have the functions of supporting the first alignment layer and the second alignment layer formed on these substrate layers, And the function of the supporting layer of the first liquid crystal layer and the second liquid crystal layer. The substrate layer is preferably a thin film formed of a resin material.

As the resin material, for example, resin materials excellent in transparency, mechanical strength, thermal stability, stretchability, and the like can be used. Specifically, polyolefin-based resins such as polyethylene and polypropylene; cyclic polyolefin-based resins such as norbornene-based polymers; polyesters such as polyethylene terephthalate and polyethylene naphthalate; Resins; (meth)acrylic resins such as (meth)acrylic acid and polymethyl (meth)acrylate; cellulose ester resins such as cellulose triacetate, cellulose diacetate, and cellulose acetate propionate; polyvinyl alcohol , polyvinyl acetate and other vinyl alcohol-based resins; polycarbonate-based resins; polystyrene-based resins; polyarylate-based resins; polyether-based resins; polyether-based resins; polyamide-based resins; polyimides resin; polyether aldehyde resin; polyphenylene sulfide resin; polyphenylene ether resin, and their mixtures, copolymers, etc. Among these resins, it is preferable to use cyclic Any one of polyolefin resin, cellulose ester resin, and (meth)acrylic resin, or a mixture thereof.

The substrate layer may be a single layer of one type of resin or a mixture of two or more types, or may have a multilayer structure of two or more layers. When having a multilayer structure, the resins constituting each layer may be the same or different, and may also be a coating or hardened layer such as a hard coat layer.

Optional additives may be added to the resin material constituting the film formed of the resin material. Additives include, for example, ultraviolet absorbers, antioxidants, lubricants, plasticizers, release agents, anti-coloring agents, flame retardants, nucleating agents, antistatic agents, pigments, and coloring agents.

The thickness of the first base material layer and the second base material layer is not particularly limited, but it is preferably 1 to 300 μm , more preferably 10 to 200 μm from the viewpoint of workability such as general strength and handleability. , And more preferably 30 to 120 μ m.

When the first liquid crystal layer attached to the substrate layer has the first alignment layer described later, or the second liquid crystal layer attached to the substrate layer has the second alignment layer described later, in order to improve the relationship between the first liquid crystal layer and the first alignment layer The adhesion, and the adhesion between the second liquid crystal layer and the second alignment layer, can be at least on the surface of the first substrate layer on which the first alignment layer is formed, and at least on the surface of the second substrate layer on which the second alignment layer is formed. 2. The surface on the side of the alignment layer is subjected to corona treatment, plasma treatment, flame treatment, etc. to form a primer layer.

The substrate layer can be peeled off from the liquid crystal layer or the alignment layer described later (the first alignment layer or the second alignment layer). The strength of the peeling force between the substrate layer and the liquid crystal layer or the alignment layer must be taken into account when peeling off the substrate layer. order to decide. In addition to using the test piece for measurement with a liquid crystal layer on the base layer, or the test piece for measurement with an alignment layer and a liquid crystal layer on the base layer, the peeling force can also be used to measure the distance between the peeling layer and the adhesive layer. The method of peeling force was measured similarly. The peeling force between the substrate layer and the liquid crystal layer or the alignment layer is preferably 0.01 to 0.50N/25mm, more preferably 0.03 to 0.20N/25mm, and more preferably 0.05 to 0.05N/25mm. 0.18N/25mm. If the peeling force is lower than the above-mentioned lower limit, floating may occur between the base material layer and the liquid crystal layer or alignment layer during transportation. Also, if the peeling force exceeds the above-mentioned upper limit, the liquid crystal layer, or the liquid crystal layer and the alignment layer cannot be transferred to other liquid crystal layers or optical films, etc. due to the high adhesiveness. In the process, there is a possibility that the peeling interface may change during the transportation of each member.

The peeling force between the first substrate layer and the first liquid crystal layer or the first alignment layer described later (hereinafter also referred to as "first peeling force"), and the relationship between the second substrate layer and the second liquid crystal layer or the The difference in peeling force (hereinafter, also referred to as "second peeling force") between the second alignment layers described later is preferably at least 0.01 N/25 mm, more preferably at least 0.03 N/25 mm. When peeling the first base layer from the liquid crystal laminate with the base layer first, the second peeling force is preferably greater than the first peeling force.

(alignment layer)

The first liquid crystal layer with the substrate layer may also contain a first alignment layer between the first substrate layer and the first liquid crystal layer. In addition, the second liquid crystal layer with the base material layer may also include a second alignment layer between the second base material layer and the second liquid crystal layer.

The first alignment layer and the second alignment layer have an alignment control force for aligning liquid crystal compounds contained in the first liquid crystal layer and the second liquid crystal layer formed on the alignment layers to a desired direction. The first alignment layer and the second alignment layer can be, for example, an alignment polymer layer formed with an alignment polymer, a photo-alignment polymer layer formed with a photo-alignment polymer, or a layer with a concave-convex pattern or multiple layers on the surface. The groove alignment layer of the groove (groove), the first alignment layer and the second alignment layer, may be the same type of layer, or may be different types of layers. The thickness of the first alignment layer and the second alignment layer is usually 10 to 4000 nm, preferably 50 to 3000 nm.

A composition in which an alignment polymer is dissolved in a solvent can be applied to a substrate layer (the first substrate layer or the second substrate layer), the solvent is removed, and rubbing treatment is performed as necessary to form an alignment polymer layer. In this case, in the alignment polymer layer formed with the alignment polymer, the The alignment control force can be adjusted arbitrarily according to the surface state or friction condition.

A composition containing a polymer having a photoreactive group or a monomer and a solvent can be applied to a substrate layer (the first substrate layer or the second substrate layer), and photoalignment can be formed by irradiating light such as ultraviolet rays. permanent polymer layer. In particular, when it is desired to exhibit alignment control force in the horizontal direction, it can be formed by irradiating polarized light. In this case, in the photo-alignment polymer layer, the alignment control force can be adjusted arbitrarily according to the polarized light irradiation conditions to the photo-alignment polymer.

The groove alignment layer can be formed by, for example, the following methods: on the surface of the photosensitive polyimide film, exposing and developing through an exposure mask with pattern-shaped slits to form a concave-convex pattern; A method of forming an uncured layer of an active energy ray-curable resin on a plate-shaped master plate having grooves on its surface, and transferring this layer to a base material layer (first base material layer or second base material layer) to harden it; The base material layer (the first base material layer or the second base material layer) forms an uncured layer of active energy ray-curable resin, and on this layer, a roll-shaped main plate having concavities and convexities is pressed to form concavities and convexities and then hardened method etc.

When the first liquid crystal layer with the base material layer contains the first alignment layer, when the first base material layer is peeled off, the first alignment layer can be peeled off simultaneously with the first base material layer, or the first alignment layer can be left on the first liquid crystal layer. an alignment layer. When the second liquid crystal layer with the base material layer contains the second alignment layer, when the second base material layer is peeled off, the second alignment layer can be peeled off simultaneously with the second base material layer, and the second alignment layer can also be left on the second liquid crystal layer. Two alignment layers. In addition, whether the first alignment layer is to be peeled off simultaneously with the first substrate layer or remains in the first liquid crystal layer can be set by adjusting the relationship between the adhesion forces between the layers, for example, by adjusting the first substrate layer The surface treatment such as corona treatment, plasma treatment, flame treatment, primer layer treatment, etc. of the material layer, or the composition of the liquid crystal layer forming composition used to form the first liquid crystal layer can be adjusted. Similarly, through the surface treatment of the second alignment layer, the second alignment layer can be peeled off simultaneously with the first substrate layer, or can remain in the second liquid crystal layer.

When the first alignment layer remains on the first liquid crystal layer, the first adhesive layer can be disposed on on the first alignment layer. Also, when the second alignment layer remains on the second liquid crystal layer, the second adhesive layer can be disposed on the second alignment layer.

(circular polarizer)

The optical layered body of this embodiment can be used as a circular polarizing plate. When using the optical laminate 73 with an adhesive layer shown in Fig. 6 (b) as a circular polarizer, the optical film 60 can be used as a polarizer, a polarizer, or a polarizer with a protective film, and the first The liquid crystal layer 12 serves as a 1/2 wavelength retardation layer, and the second liquid crystal layer 22 serves as a 1/4 wavelength retardation layer. Or, similar to the above, after using the optical film 60 as a polarizer, a polarizer, or a polarizer with a protective film, the first liquid crystal layer 12 is used as a 1/4 wavelength retardation layer with reverse wavelength dispersion, and the second The liquid crystal layer 22 is used as a positive C plate, so that a circular polarizing plate can also be obtained.

[Example]

Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated more concretely, this invention is not limited to these examples. "%" and "parts" in Examples and Comparative Examples are % by mass and parts by mass unless otherwise specified.

[Preparation of adhesive layer with double-sided spacer film]

The adhesive was produced as follows. In a reaction vessel equipped with a stirrer, a thermometer, a reflux cooler, a dropping device, and a nitrogen introduction pipe, 97.0 parts of n-butyl acrylate, 1.0 parts of acrylic acid, 0.5 parts of 2-hydroxyethyl acrylate, 200 parts of ethyl acetate, and 0.08 parts of 2,2'-azobisisobutyronitrile, and the gas in the reaction container was replaced with nitrogen. The temperature of the reaction solution was raised to 60° C. while stirring under a nitrogen atmosphere, and after reacting for 6 hours, it was cooled to room temperature. As a result of measuring the weight average molecular weight of a part of the obtained solution, it was confirmed that 1.8 million (meth)acrylate polymers were produced.

Mix 100 parts of (meth)acrylate polymer obtained above (solid content conversion value; the same below) with trimethylolpropane-modified toluene diisocyanate (Dongsuo Co., Ltd. Made by the company, trade name "CoronateL"), 0.30 parts of 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Industries Co., Ltd., trade name "KBM403") as a silane coupling agent, mixed well, And dilute it with ethyl acetate to prepare a coating solution of the adhesive composition.

On the release-treated surface (peeling surface) of the first separator (manufactured by Lintec Co., Ltd.: SP-PLR382190) to be the peeling layer, apply the coating solution of the above-mentioned adhesive composition with a sprayer, and then heat it at 100°C Dry for 1 minute to form an adhesive layer, and attach another piece of the second separator (manufactured by Lintec Co., Ltd.: SP-PLR381031) on the opposite side of the separator with the adhesive layer attached, to obtain a double-sided separator Adhesive layer of the film.

[Preparation of adhesive composition]

After mixing the cationic hardening components a1 to a3 shown below and the cationic polymerization initiator, and then mixing the cationic polymerization initiator and sensitizer shown below, defoaming is carried out to prepare a photocurable form Adhesive composition. Also, the following compounding quantities are based on solid content.

． Cationic hardening component a1 (70 parts):

3',4'-Epoxycyclohexylmethyl 3',4'-epoxycyclohexanecarboxylate (trade name: CEL2021P, manufactured by Daicel Co., Ltd.)

． Cationic hardening ingredient a2 (20 parts):

Neopentyl glycol diglycidyl ether (trade name: EX-211, manufactured by Nagase ChemteX Co., Ltd.)

． Cationic hardening ingredient a3 (10 parts):

2-Ethylhexyl glycidyl ether (trade name: EX-121, manufactured by Nagase ChemteX Co., Ltd.)

． Cationic polymerization initiator (2.25 parts (solid weight)):

Product name: 50% propylene carbonate solution of CPI-100 (manufactured by San-Apro Co., Ltd.)

． Sensitizer (2 parts):

1,4-Diethoxynaphthalene

[Preparation of the first liquid crystal layer with substrate layer and the second liquid crystal layer with substrate layer]

(Preparation of composition (1) for photoalignment layer formation)

The following components were mixed, and the resulting mixture was stirred at a temperature of 80° C. for 1 hour, whereby a composition (1) for forming an optical alignment layer was prepared.

． Photoalignment material (5 parts):

． Solvent (95 parts): cyclopentanone

(Preparation of Alignment Layer Forming Composition (2))

2-butoxyethanol was added to Sunever SE-610 (manufactured by Nissan Chemical Industries, Ltd.), a commercially available alignment polymer, to obtain a composition (2) for forming an alignment layer. The obtained composition for forming an alignment layer (2) had a solid content ratio of 1% to the total amount of the composition, and a solvent content ratio of 99% to the total amount of the composition. The solid content of SuneverSE-610 is converted from the concentration recorded in the product specification.

(Preparation of liquid crystal layer forming composition (A-1))

The following components were mixed, and the resulting mixture was stirred at a temperature of 80° C. for 1 hour to prepare a composition (A-1) for forming a liquid crystal layer. The polymerizable liquid crystal compound A1 and the polymerizable liquid crystal compound A2 were synthesized by the method described in JP-A-2010-31223.

． Polymeric liquid crystal compound A1 (80 parts):

． Polymeric liquid crystal compound A2 (20 parts):

． Polymerization initiator (6 parts):

啉基苯基)丁烷-4-酮(Irgacure369：汽巴特殊化藥公司製) 2-Dimethylamino-2-benzyl-1-(4-

Linylphenyl)butan-4-one (Irgacure 369: manufactured by Ciba Special Chemicals Co., Ltd.)

． Solvent (400 parts): cyclopentanone

(Preparation of liquid crystal layer forming composition (B-1))

The following components were mixed, and the resulting mixture was stirred at a temperature of 80° C. for 1 hour to prepare a composition (B-1) for forming a liquid crystal layer.

． Polymeric liquid crystal compound LC242 (manufactured by BASF Corporation) (19.2%):

． Polymerization initiator (0.5%):

Irgacure (registered trademark) 907 (manufactured by BASF Japan Co., Ltd.)

． Reactive Additives (1.1%):

Laromer (registered trademark) LR-9000 (manufactured by BASF Japan Co., Ltd.)

． Solvent (79.1%): Propylene glycol 1-monomethyl ether 2-acetate

(Manufacture of the first liquid crystal layer (i) with substrate layer)

A polyethylene terephthalate (PET) film (the first substrate layer) with a thickness of 100 μm was treated with a corona treatment device (AGF-B10, manufactured by Kasuga Electric Co., Ltd.) at an output of 0.3 kW at a processing speed The condition of 3m/min is processed once. On the corona-treated surface, apply the photoalignment layer-forming composition (1) with a bar coater, dry at 80° C. for 1 minute, and use a polarized UV irradiation device (SPOT CURE SP-7; Ushio Electric Co., Ltd. made by the company), polarized UV exposure was performed with a cumulative light intensity of 100 mJ/cm ² to obtain a photo-alignment layer. As a result of measuring the thickness of the obtained photo-alignment layer with a laser microscope (LEXT, manufactured by Olympus Co., Ltd.), it was 100 nm.

Next, the composition (A-1) for forming a liquid crystal layer was coated on the photoalignment layer using a bar coater, dried at 120°C for 1 minute, and then dried using a high-pressure mercury lamp (Unicure VB-15201BY-A, manufactured by Ushio Electric Co., Ltd.). ), and measure ultraviolet rays (under a nitrogen atmosphere, wavelength: 365nm, irradiation intensity at 365nm: 10mW/cm ² , cumulative light intensity: 1000mJ/cm ² ), thereby forming the first liquid crystal layer as a retardation layer, and obtaining The first liquid crystal layer (i) with a substrate layer (Fig. 1 (a)). The thickness of the first liquid crystal layer is 2 μm .

(Manufacture of the first liquid crystal layer (ii) with substrate layer)

Except that the irradiation intensity of ultraviolet irradiation using a high-pressure mercury lamp is 50mW/cm ² , and the manufacture of the first liquid crystal layer (i) with the base material layer, the first liquid crystal layer with the base material layer (i) is prepared in the same order. ii) (Fig. 1(a)). The thickness of the first liquid crystal layer is 2 μm .

(Manufacture of the first liquid crystal layer (iii) with substrate layer)

Except that the irradiation intensity of ultraviolet irradiation using a high-pressure mercury lamp is 400mW/cm ² , and the manufacture of the first liquid crystal layer (i) with the base material layer, the first liquid crystal layer (i) with the base material layer is prepared in the same order. iii) (Fig. 1(a)). The thickness of the first liquid crystal layer is 2 μm .

(Manufacture of the second liquid crystal layer with substrate layer)

A polyethylene terephthalate (PET) film (second substrate layer) with a thickness of 38 μm was treated with a corona treatment device (AGF-B10, manufactured by Kasuga Electric Co., Ltd.) at an output of 0.3 kW at a processing speed The condition of 3m/min is processed once. On the corona-treated surface, the composition (2) for forming an alignment layer was coated with a bar coater, and dried at 90° C. for 1 minute to obtain an alignment layer. As a result of measuring the thickness of the obtained alignment layer with a laser microscope (LEXT, manufactured by Olympus Co., Ltd.), it was 34 nm.

Next, apply the composition (B-1) for forming a liquid crystal layer on the alignment layer using a bar coater, dry it at 90° C. for 1 minute, and then use a high-pressure mercury lamp (Unicure VB-15201BY-A, manufactured by Ushio Electric Co., Ltd.) , to measure ultraviolet rays (under a nitrogen atmosphere, wavelength: 365nm, cumulative light intensity at 365nm wavelength: 1000mJ/cm ² ), thereby forming a second liquid crystal layer as a retardation layer, and obtaining a second liquid crystal layer with a substrate layer (Figure 1(b)). The thickness of the second liquid crystal layer is 1 μm .

[Preparation of optical film with spacer]

Circular polyolefin film with protective film (thickness 23 μ m, ZF-14, manufactured by Zeon Co., Ltd., Japan) with a length of 380 mm in the MD direction and a length of 180 mm in the TD direction (hereinafter also referred to as "COP with protective film") ") on the opposite side of the protective film side of the ring-shaped polyolefin film surface, corona treatment (800W, 10m/min, rod width 700mm, 1Pass). The corona-treated surface of the COP with protective film and the exposed surface exposed by peeling off the first spacer film from the adhesive layer with double-sided spacer film prepared above are pasted using an automatic laminating device HALTEC (Sankyo Co., Ltd.) combined to obtain an optical film with a spacer.

[Measurement of TD curl of optical laminate]

Place the optical laminates with substrate layers obtained in each of the examples and comparative examples in an environment with a temperature of 23°C and a relative humidity of 55% for 24 hours, and then cut them into rectangles with a length of 150 mm on the long side and 50 mm on the short side. The cut pieces were cut, the protective film was peeled off, and polyethylene terephthalate (the second substrate layer) with a thickness of 38 μm was used to make test pieces. Cut the slice so that its long side forms an angle of 45 degrees with the TD direction of the optical laminate with the substrate layer (the TD direction of the second liquid crystal layer with the substrate layer and the first liquid crystal layer with the substrate layer) way to cut.

After the test piece is fully destaticized, place it on the reference plane (horizontal platform) with the concave side of the test piece facing upwards, and in the diagonal line of the test piece, its extension direction is opposite to the direction parallel to the above-mentioned TD direction. Measure the height from the datum plane at the two corners on the closest diagonal. For the measured value, if the test piece is placed on the reference plane with the side of the cyclic polyolefin film (hereinafter also referred to as "COP film") exposed by peeling off the protective film as the upper side, when the above two corners of the test piece have When floating, the curl is regarded as a positive curl, and the height of the angle from the reference plane is represented by a positive value. On the other hand, if the test piece is placed on the reference plane so that the COP film side is on the lower side, when the above-mentioned two corners of the test piece are raised, the curl is regarded as a reverse curl, and the curl is counted from the reference plane. The height of the corner is represented by a negative value. The average value of the values measured for the above two angles was regarded as the TD curl value of the optical layered body.

Also, since the optical film with the adhesive layer of the protective film and the spacer film peeled off from the optical film with the release film has a TD curl value of 0 when measured in the same procedure as above, the TD curl value of the optical laminate, It is estimated that it is the same as the TD curl value of the laminated body which has the layer structure of the 1st liquid crystal layer/1st adhesive layer/2nd liquid crystal layer.

[Measurement of TD curl of the first liquid crystal layer and the second liquid crystal layer]

(Measurement of TD curl of auxiliary film for measurement)

The above-mentioned optical film with a septum is used as an auxiliary film for measurement with a septum. Place the auxiliary film for measurement with a spacer in an environment with a temperature of 23°C and a relative humidity of 55% for 24 hours, and then cut it into a rectangular piece with a length of 150 mm on the long side and a length of 50 mm on the short side, and peel off the protective film and the second 2. The diaphragm is used as the test piece of the auxiliary film for measurement. This cut piece is cut out in the same direction as the cutting direction of the cut piece when measuring the TD curl of the first liquid crystal layer and the second liquid crystal layer described later.

After fully removing the static electricity from the test piece of the auxiliary film for measurement, in the same procedure as above, in the diagonal line of the test piece, measure the distance from the extending direction and the TD direction (together with the first liquid crystal layer and the second liquid crystal layer described later). The average value of the height from the reference plane of the two corners on the relatively close diagonal in the parallel direction of the TD curl measurement of the two liquid crystal layers is taken as the TD curl value of the auxiliary film for measurement. The TD curl value of the auxiliary film for measurement is 0.0 mm.

(Measurement of TD curl of the first liquid crystal layer and the second liquid crystal layer)

The above-mentioned optical film with a septum is used as an auxiliary film for measurement with a septum. The first liquid crystal layer of the first liquid crystal layer of the first liquid crystal layer of the base material layer obtained above is attached to the adhesive layer exposed by peeling off the second spacer film from the auxiliary film for measurement with the spacer film, using the automatic laminating device HALTEC, Thus, a first liquid crystal layer having an auxiliary film for measurement was obtained. Place the first liquid crystal layer with the auxiliary film for measurement in an environment with a temperature of 23°C and a relative humidity of 55% for 24 hours. film and a polyethylene terephthalate film (first substrate layer) to obtain a laminate (a) (layer structure, ring-shaped polyolefin film/adhesive layer/first liquid crystal layer) as a test piece. The cut sheet is cut in such a way that its long side forms an angle of 45 degrees with the TD direction of the first liquid crystal layer with the substrate layer.

After the obtained laminate (a) is fully destaticized, in the same procedure as above, in the diagonal of the laminate (a), measure the pair that is relatively close to the direction parallel to the above-mentioned TD direction. The average value of the height from the reference plane of the two corners on the corner line was taken as the TD curl value of the laminate (a). The difference between the TD curl value of the laminate (a) and the TD curl value of the auxiliary film for measurement obtained above was calculated as the curl value of the first liquid crystal layer. Table 1 shows the curl value of the first liquid crystal layer of the first liquid crystal layer with each substrate layer. The "cylindrical shape" in Table 1 means that the curl value of the first liquid crystal layer is estimated to exceed 20 mm because the laminate (a) is curled into a cylindrical shape.

Also, except that the second liquid crystal layer with the base material layer was used instead of the first liquid crystal layer with the base material layer, the laminate (b) (layer structure, COP film/adhesive layer/second liquid crystal layer) was obtained in the same manner as above. liquid crystal layer). Except having used the laminated body (b) instead of the said laminated body (a), the curl value of the 2nd liquid crystal layer was calculated similarly to the above. Table 1 shows the curl values of the second liquid crystal layer of the second liquid crystal layer with the substrate layer.

[Measurement of storage elastic modulus E]

The storage elastic modulus E[Pa] at a temperature of 30°C when an active energy ray-curable adhesive is used as the first adhesive layer is calculated by the following procedure. On one side of a cyclic polyolefin resin film with a thickness of 50 μm , use a coater [rod coater, manufactured by Daiichi Rika Co., Ltd.] to coat an active energy ray-curable adhesive on the coated side A circular polyolefin resin film with a thickness of 50 μm was laminated again. Next, ultraviolet rays were irradiated with a "D lamp" manufactured by Fusion UV Systems Co., Ltd. so that the cumulative light intensity was 1500 mJ/cm ² (UVB), and the adhesive composition layer was cured. It was cut into a size of 5mm×30mm, and one of the cyclic olefin-based resin films was peeled off to obtain an adhesive hardened layer with a resin film. The hardened adhesive layer with the resin film was gripped at a distance of 2 cm between the clamps using a dynamic viscoelasticity measuring device "DVA-220" manufactured by IT Measurement Control Co., Ltd. so that the long side was in the direction of stretching. The frequency of stretching and shrinking was set at 10 Hz, the heating rate was set at 10°C/min, and the temperature was raised to obtain the storage elastic modulus E at a temperature of 30°C.

[Measurement of thickness t]

The thickness t of the first adhesive layer (adhesive layer for bonding the first liquid crystal layer and the second liquid crystal layer) was measured as follows using a contact film thickness meter (Digimicrohead MH-15M, manufactured by Nikon Co., Ltd.). First, the film thicknesses of the first liquid crystal layer with the base material layer and the second liquid crystal layer with the base material layer were respectively measured using the above-mentioned contact film thickness gauge. Next, for the liquid crystal laminate with both substrate layers obtained by laminating the first liquid crystal layer with the substrate layer and the second liquid crystal layer with the substrate layer after the film thickness was measured, the The film thickness was measured at the same position as the film thickness of the first liquid crystal layer and the second liquid crystal layer with the substrate layer. The difference between the measured film thickness of the liquid crystal laminate with both base layers and the total film thickness of the first liquid crystal layer with the base layer and the second liquid crystal layer with the base layer is calculated to calculate the first adhesion. Layer thickness t.

[Example 1]

Corona treatment (800W, 10m/min, rod width 700mm, 1Pass). Use the adhesive composition prepared above to form an adhesive composition layer using a coating machine (a rod coater manufactured by First Physika Co., Ltd.), and obtain the second liquid crystal layer attached to the composition layer (No. 1 Figure (c)). Then, corona treatment was applied to the surface of the first liquid crystal layer side of the first liquid crystal layer (i) (length in the MD direction 380 mm × 180 mm in the TD length direction) prepared above under the same conditions, and the After the corona-treated surface and the adhesive composition layer of the second liquid crystal layer attached to the composition layer are pasted using a pasting device ("LPA3301" manufactured by FUJIPLA Co., Ltd.) (Fig. 1 (d)), the On the side of the second liquid crystal layer of the second liquid crystal layer attached to the base material layer, the ultraviolet irradiation device (the lamp system uses the "H lamp" made by FUSION UV SYSTEMS Co., Ltd.) of the attached conveyor, so that the irradiation intensity of the UVA area is 390mW/cm ² , the accumulated light amount is 420mJ/cm ² , the irradiation intensity in the UVB region is 400mW/cm ² , and the accumulated light amount is 400mJ/cm ² , irradiating ultraviolet rays to harden the adhesive composition and attach both sides The liquid crystal laminated body of the substrate layer (see Fig. 2 (a)). As a result of measuring the storage elastic modulus E and thickness t of the first adhesive layer of the hardened adhesive layer after the above-mentioned adhesive composition layer is hardened, the storage elastic modulus E at a temperature of 30°C is 3000 MPa, and the thickness t is 2.2 μ m.

The polyethylene terephthalate film (the first substrate layer) with a thickness of 100 μm was peeled off from the liquid crystal laminate with both substrate layers to obtain a liquid crystal laminate with a single substrate layer (Fig. 2 (b)). The exposed surface (photo-alignment layer) of the liquid crystal laminate with a single-sided substrate layer exposed by this peeling, and the adhesive exposed by peeling off the second spacer from the optical film with a spacer prepared above Layers were bonded using an automatic bonding device HALTEC (Sankyo Co., Ltd.) to obtain an optical laminate with a substrate layer (Fig. 4 (a)). Using the optical layered body with the substrate layer, TD curl was measured in the above-mentioned procedure, and the TD curl value of the optical layered body was calculated. The results are shown in Table 1.

[Example 2]

In addition to coating the adhesive composition on the second liquid crystal layer of the second liquid crystal layer attached to the substrate layer so that the thickness t of the first adhesive layer is 4.3 μm , the same steps as in Example 1 were used to prepare A liquid crystal laminate with a substrate layer and an optical laminate with a substrate layer were obtained. The storage elastic modulus E of the first bonding layer is 3000MPa. Moreover, using the obtained optical layered body with a substrate layer, TD curl was measured in the above-mentioned procedure, and the TD curl value of the optical layered body was calculated. The results are shown in Table 1.

[Example 3]

In addition to coating the adhesive composition on the second liquid crystal layer of the second liquid crystal layer attached to the substrate layer so that the thickness t of the first adhesive layer is 1.5 μm , the same steps as in Example 1 were used to prepare A liquid crystal laminate with a substrate layer and an optical laminate with a substrate layer were obtained. The storage elastic modulus E of the first bonding layer is 3000MPa. Moreover, using the obtained optical layered body with a substrate layer, TD curl was measured in the above-mentioned procedure, and the TD curl value of the optical layered body was calculated. The results are shown in Table 1.

[Example 4]

Except that the first liquid crystal layer (ii) with the substrate layer prepared above is used to replace the first liquid crystal layer (i) with the substrate layer, the same steps as in Example 3 are used to prepare the liquid crystal with the substrate layer A laminated body and an optical laminated body with a substrate layer. The storage elastic modulus E of the first bonding layer is 3000MPa. Moreover, using the obtained optical layered body with a substrate layer, TD curl was measured in the above-mentioned procedure, and the TD curl value of the optical layered body was calculated. The results are shown in Table 1.

[Example 5]

In addition to coating the adhesive composition on the second liquid crystal layer of the second liquid crystal layer attached to the substrate layer so that the thickness t of the first adhesive layer is 6.4 μm , the same steps as in Example 4 were used to prepare A liquid crystal laminate with a substrate layer and an optical laminate with a substrate layer were obtained. The storage elastic modulus E of the first bonding layer is 3000MPa. Moreover, using the obtained optical layered body with a substrate layer, TD curl was measured in the above-mentioned procedure, and the TD curl value of the optical layered body was calculated. The results are shown in Table 1.

[Comparative example 1]

Except using the first liquid crystal layer (iii) prepared above to replace the first liquid crystal layer (i) with the base layer, the same steps as in Example 3 were used to prepare the liquid crystal with the base layer A laminated body and an optical laminated body with a substrate layer. The storage elastic modulus E of the first bonding layer is 3000MPa. Moreover, using the obtained optical layered body with a substrate layer, TD curl was measured in the above-mentioned procedure, and the TD curl value of the optical layered body was calculated. The results are shown in Table 1.

[Table 1]

As shown in Table 1, it can be seen that the optical laminates obtained in Examples 1 to 5 have suppressed curling, and the optical laminates obtained in Examples 1 to 4 are in a state closer to a plane (flat). On the other hand, in Comparative Example 1, it was found that the curling of the optical layered body increased.

Claims (18)

A method for manufacturing a liquid crystal layered body. The liquid crystal layered layer system is at least sequentially laminated with a first liquid crystal layer, a first adhesive layer, and a second liquid crystal layer. The manufacturing method includes the following steps: preparing the second A liquid crystal layer step, the first liquid crystal layer of the base material layer has a first base material layer, and the aforementioned first liquid crystal layer formed by polymerizing a polymerizable liquid crystal compound on the aforementioned first base material layer; preparing the base material layer The step of the second liquid crystal layer of the material layer, the second liquid crystal layer with the base material layer has the second base material layer, and the aforementioned second liquid crystal layer formed by polymerizing the polymerizable liquid crystal compound on the aforementioned second base material layer and the lamination step is to laminate the aforementioned second liquid crystal layer of the second liquid crystal layer of the aforementioned substrate-attached layer on the side of the aforementioned first liquid crystal layer of the aforementioned first substrate-attached layer via the aforementioned first bonding layer On the other hand, wherein the first adhesive layer is an adhesive cured layer made of cured adhesive, the absolute value of the curl of the first liquid crystal layer is within 20 mm, and the curl of the second liquid crystal layer is within 20 mm. The absolute value is within 20mm. The method of manufacturing a liquid crystal laminated body as described in item 1 of the scope of the patent application, wherein, when the storage elastic modulus of the first adhesive layer at a temperature of 30°C is set as E [Pa], and the thickness is set as t [m ], the aforementioned first adhesive layer satisfies the relationship of the following formula (1), 3000≦E×t≦15000 (1). The method for manufacturing a liquid crystal laminated body as described in claim 1 or 2 of the patent claims further includes a step of peeling off the first substrate layer after the aforementioned lamination step. A liquid crystal layered body comprising at least a first liquid crystal layer, a first adhesive layer, and a second liquid crystal layer sequentially laminated, wherein, The first liquid crystal layer and the second liquid crystal layer are hardened layers of polymerizable liquid crystal compounds, the first adhesive layer is an adhesive hardened layer made of cured adhesive, and the amount of curl of the first liquid crystal layer The absolute value is within 20 mm, and the absolute value of the curl amount of the second liquid crystal layer is within 20 mm. The liquid crystal laminated body as described in item 4 of the scope of application, wherein, when the storage elastic modulus of the first adhesive layer at a temperature of 30°C is set as E[Pa], and the thickness is set as t[m], The aforementioned first adhesive layer satisfies the relationship of the following formula (1): 3000≦E×t≦15000 (1). The liquid crystal laminated body as described in claim 4 or 5 of the patent claims further has a second base material layer on the side opposite to the first adhesive layer of the second liquid crystal layer. The liquid crystal laminated body as described in claim 6 of the patent claims, further comprising a first base material layer on the opposite side of the first liquid crystal layer to the first adhesive layer. A method for manufacturing an optical laminate. The optical layer system is at least sequentially laminated with an optical film, a second adhesive layer, a first liquid crystal layer, a first adhesive layer, and a second liquid crystal layer. The manufacturing method includes the following steps: By peeling off the first exposed surface side of the first base material layer from the liquid crystal laminate manufactured by the method for producing a liquid crystal laminate described in claim 3, by claiming the liquid crystal laminate from claim 7 The first exposed surface side of the liquid crystal laminated body described in item 6 is peeled off from the first base material layer, or the first liquid crystal layer side of the liquid crystal laminated body described in claim 6, and the second liquid crystal layer is laminated in sequence. 2. Steps of bonding layer and optical film. The method for manufacturing an optical laminate described in claim 8 of the patent application further includes the step of peeling off the second substrate layer after the step of sequentially laminating the second adhesive layer and the optical film. The method for manufacturing an optical laminate as described in claim 9 of the scope of the patent application further includes the following steps: preparing an adhesive layer with a release layer laminated with an adhesive layer and a release layer; The step of laminating the side of the adhesive layer with the adhesive layer with release layer on the second exposed surface side exposed by the second base material layer. The method for producing an optical laminate as described in claim 10 further includes the step of peeling off the peeling layer after the step of laminating the peeling layer-attached adhesive layer on the side of the adhesive layer. The method for producing an optical laminate according to any one of claims 8 to 11, wherein the optical film includes a polarizing plate. An optical layered body, which is at least sequentially laminated with an optical film, a second adhesive layer, a first liquid crystal layer, a first adhesive layer, and a second liquid crystal layer, wherein the first liquid crystal layer and the second liquid crystal layer are The hardened layer of the polymerizable liquid crystal compound, the first adhesive layer is an adhesive hardened layer composed of a cured product of a curable adhesive, the absolute value of the curl of the first liquid crystal layer is within 20 mm, and the second liquid crystal layer The absolute value of the crimp is within 20mm. The optical laminate described in claim 13 of the scope of the patent application, wherein, when the storage elastic modulus of the first adhesive layer at a temperature of 30°C is E[Pa] and the thickness is t[m], the above-mentioned The first bonding layer satisfies the relationship of the following formula (1), 3000≦E×t≦15000 (1). The optical laminate according to claim 13 or 14, further comprising a second substrate layer on the side opposite to the first adhesive layer of the second liquid crystal layer. The optical laminate as described in claim 13 or 14, further comprising an adhesive layer on the opposite side of the second liquid crystal layer to the first adhesive layer. The optical laminate according to claim 16, further comprising a release layer on the side of the adhesive layer opposite to the second liquid crystal layer. The optical laminate according to claim 13 or 14, wherein the optical film includes a polarizing plate.

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