TW202024684A - 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 methods for manufacturing the same.

Compared with liquid crystal display devices, organic EL display devices using organic light-emitting diodes (OLED) can not only achieve lighter weight and thinner, but also achieve wide viewing angles, fast response speeds, and high contrast. Because of its high quality, it is used in various fields such as smart phones, TVs, and digital cameras. In organic EL display devices, it is known to use a circular polarizer or the like to improve the anti-reflection performance because it can suppress the decrease in visibility caused by the reflection of an external light source.

For example, in Patent Documents 1 and 2, as a film with anti-reflection function used in image display panels of organic EL display devices, etc., a laminate is disclosed, which is attached to a linear polarizing plate (optical film), and has two layers. A retardation layer formed by a liquid crystal compound and laminated with an interposing layer.

Patent Document 1: Japanese Patent Application Publication No. 2015-230386

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

The above-mentioned film is used by bonding the optical display element, but if the film is bent so that the side to be bonded to the optical display element is concave, that is, when the so-called rewind occurs, the film and the optical display element are bonded together At this time, air bubbles may penetrate, and wrinkles may also occur. Due to these problems, there is a tendency for defects such as unevenness to be easily recognized. Such a bad situation will become the cause of the defect of the image display panel, so it is hoped that the film can be suppressed.

The object of the present invention is to provide an optical laminate with suppressed rewinding, a liquid crystal laminate used in the manufacture of the optical laminate, and a manufacturing method thereof.

[1] A method for manufacturing a liquid crystal laminate, wherein the liquid crystal laminate system has at least a first liquid crystal layer, a first adhesive layer, and a second liquid crystal layer laminated in this order, and the manufacturing method includes the following steps:

The step of preparing a first liquid crystal layer with a substrate layer, the first liquid crystal layer with a substrate layer having a first substrate layer, and the aforementioned first substrate layer formed by polymerizing a polymerizable liquid crystal compound on the aforementioned first substrate layer A liquid crystal layer;

The step of preparing a second liquid crystal layer with a substrate layer, the second liquid crystal layer with a substrate layer having a second substrate layer, and the aforementioned second substrate layer formed by polymerizing a polymerizable liquid crystal compound on the aforementioned second substrate layer Two liquid crystal layers; and

The laminating step involves laminating the second liquid crystal layer of the second liquid crystal layer with the second substrate layer on the first liquid crystal layer side of the first liquid crystal layer with the substrate layer through the first adhesive layer, among them,

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

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

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

[2] The method for manufacturing a liquid crystal laminate as described in [1], wherein when the storage modulus (storage modulus) of the first adhesive layer at a temperature of 30°C is set to E[Pa], the thickness When it is set to t[m], the aforementioned 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 as described in [1] or [2], which is after the lamination step, and further includes a step of peeling off the first substrate layer.

[4] A liquid crystal laminated body, which is a liquid crystal laminated body in which at least a first liquid crystal layer, a first adhesive layer, and a second liquid crystal layer are laminated in this order, 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 cured layer composed of a cured product of a curable adhesive,

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

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

[5] The liquid crystal laminate according to [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], wherein the second liquid crystal layer further has a second substrate layer on the side opposite to the first adhesive layer.

[7] The liquid crystal laminate according to [6], wherein the first liquid crystal layer further has a first substrate layer on the side opposite to the first adhesive layer.

[8] A method of manufacturing an optical laminate, the optical laminate system having at least sequentially laminated 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:

In the liquid crystal laminated body manufactured by the method of manufacturing the liquid crystal laminated body described in [3], the first exposed surface side exposed by the first base material layer is peeled off, by removing the liquid crystal described in [7] The laminated body peels off the exposed first surface side of the first base material layer or the liquid crystal laminated body described in [6] on the side of the first liquid crystal layer, and sequentially laminates the second adhesive layer and the optical film .

[9] The method for manufacturing an optical laminate as described in [8], which 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.

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

The step of preparing an adhesive layer with an adhesive layer and a release layer attached to the release layer; and

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

[11] The method for manufacturing an optical laminate as described in [10], which further includes a step of peeling off the peeling layer after the step of laminating the peeling layer-attached adhesive layer on the adhesive layer side.

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

[13] An optical laminate comprising at least an optical film, a second adhesive layer, a first liquid crystal layer, a first adhesive layer, and a second liquid crystal layer laminated in this order, 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 cured layer composed of a cured product of a curable adhesive,

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

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

[14] The optical laminate according to [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 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], wherein the second liquid crystal layer further has a second base layer on the side opposite to the first adhesive layer.

[16] The optical laminate as described in [13] or [14], wherein the second liquid crystal layer has an adhesive layer on the side opposite to the first adhesive layer.

[17] The optical laminate according to [16], wherein the adhesive layer further has a release layer on the side opposite to the second liquid crystal layer.

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

According to the present invention, it is possible to manufacture an optical laminate with suppressed rewinding.

10‧‧‧The first liquid crystal layer with substrate layer

11‧‧‧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 subsequent layer

31a‧‧‧Adhesive composition layer

32‧‧‧Second layer

33‧‧‧Adhesive layer

40‧‧‧Liquid crystal laminates with substrate layers on both sides (liquid crystal laminates)

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

50‧‧‧Second adhesive layer with peeling layer

51‧‧‧First peeling layer

53‧‧‧Second peeling layer

58‧‧‧Adhesive layer with peeling layer

60‧‧‧Optical Film

61‧‧‧Optical film with second adhesive layer

70‧‧‧Optical laminate with peeled base layer (optical laminate)

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

72‧‧‧Optical laminate with peeling 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.

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

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

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

Fig. 5 is a schematic cross-sectional view after the manufacturing step of the optical laminate shown in Fig. 4 schematically.

Figures 6 (a) and (b) are schematic cross-sectional views that schematically show the subsequent steps of manufacturing the optical laminate shown in Figure 5.

Hereinafter, preferred embodiments of the optical laminate, the liquid crystal laminate, and the manufacturing method thereof 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 of manufacturing the liquid crystal laminate of this embodiment, and Figures 3 to 6 schematically show the optics of this embodiment A schematic cross-sectional view of an example of the manufacturing steps of the manufacturing method of the laminate. In the figure, W represents the width direction.

(Optical laminate)

As shown in FIGS. 4 and 6, the optical laminate system of this embodiment includes at least 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 persons. Here, the first adhesive layer is an adhesive cured layer composed of a cured product of a curable adhesive. In addition, the first liquid crystal layer 12 and the second liquid crystal layer 22 are hardened layers of a polymerizable liquid crystal compound. The first liquid crystal layer 12 can be formed by polymerizing the polymerizable liquid crystal compound on the first substrate layer 11. The second liquid crystal layer 22 Can be on the second base The material layer 21 is formed by polymerizing a polymerizable liquid crystal compound. 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 curl amount of the first liquid crystal layer 12 and the second liquid crystal layer 22 is to be a rectangle with a long side of 150 mm in length and a short side of 50 mm in length, and the long side is the optical laminate. In the first liquid crystal layer or the second liquid crystal layer cut out at an angle of 45 degrees in the TD direction, it is evaluated that in the diagonal, the extending direction is relatively close to the direction parallel to the TD direction of the optical laminate The curl generated on the diagonal line is calculated by the procedure described in the embodiment described later.

The curl amount of the first liquid crystal layer 12 and the second liquid crystal layer 22 can be determined by the type of polymerizable liquid crystal compound used to form the first liquid crystal layer 12 and the second liquid crystal layer 22, and the polymer of the polymerizable liquid crystal compound (hardening degree ), the types of additives contained in the composition for forming the liquid crystal layer, etc. are adjusted. The degree of polymerization of the polymerized liquid crystal compound can be determined by the type or amount of 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 cured. The irradiation intensity or irradiation time (irradiation amount) of the energy ray is adjusted. The absolute value of the curl amount of the first liquid crystal layer 12 and the second liquid crystal layer 22 is preferably independently 15 mm or less, more preferably 12 mm or less, more preferably 9 mm or less, or 0 mm, and more preferably It is 1 mm or more, more preferably 3 mm or more. The smaller the absolute value of the amount of curl, the more it is possible to suppress curl deformation (hereinafter, also referred to as "rewind") with the second liquid crystal layer 22 as the inner side and bend into a bow shape, and the easier it is to make the optical laminate flat. Flat) state.

As shown in FIG. 6(b), there is 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 this order. The adhesive layer-attached optical laminate 73 (optical laminate) is used by bonding the adhesive layer 33 to the optical display element. At this time, in the optical layered body 73 to which the adhesive layer is attached, if rewind occurs (the side of the adhesive layer 33 is the inner side) Bending into an arcuate shape), when bonding to the optical display element, there is a tendency for defects such as unevenness to be easily generated due to the mixing of bubbles and wrinkles. However, since the absolute value of the curl amount of the first liquid crystal layer 12 and the second liquid crystal layer 22 of the adhesive layer-attached optical laminate 73 is 20 mm or less, the occurrence of curling can be suppressed, and the bonding to the optical display element can be suppressed The above-mentioned undesirable situation arising from the time.

The reason for this can be estimated as follows. The first liquid crystal layer 12 and the second liquid crystal layer 22 of the optical laminate 73 with the adhesive layer (hereinafter, the two are also referred to as "liquid crystal layers") can be formed by the following methods: On the substrate layer 11 and the second substrate layer 21 (hereinafter, both are also referred to as "substrate layer"), a composition for forming a liquid crystal layer containing a polymerizable liquid crystal compound is coated and dried, and the composition is dried by ultraviolet rays. Iso-active energy ray irradiation polymerizes and hardens the polymerizable liquid crystal compound to form it. It is presumed that the liquid crystal layer formed through the above-mentioned coating, drying, polymerization, hardening, etc., has leftovers during the drying of the composition for forming the liquid crystal layer accompanying the coating or the hardening of the polymerizable liquid crystal compound. The resulting contraction force. In the state where the liquid crystal layer exists on the substrate layer, the above-mentioned shrinkage stress is suppressed by the substrate layer, but the substrate layer is generally peeled off in the step of manufacturing the liquid crystal laminate or optical laminate. Therefore, it is considered that the shrinkage stress of the liquid crystal layer is liberated when the base layer is peeled off, and the liquid crystal layer is affected by the liberated shrinkage stress, and the adhesive layer-attached optical laminate 73 is deformed and curled.

As shown in Fig. 6(b), the adhesive layer-attached optical laminate 73 has a first liquid crystal layer 12 and a second liquid crystal layer 22 interposed and laminated on only one side of the optical film 60 showing higher rigidity In the structure of, the shrinkage stress remaining in the liquid crystal layers will act to cause the adhesive layer-attached optical laminate 73 to curl inwardly from the liquid crystal layer side, so it tends to be rolled back easily.

Therefore, in the adhesive layer-attached optical laminate 73 of the present embodiment, the first liquid crystal layer 12 and the second liquid crystal layer 22 use those whose absolute value of the curl amount is 20 mm or less. Therefore, it is inferred that even if the first liquid crystal layer 12 or the second liquid crystal layer is released due to the peeling of the first substrate layer 11 or the second substrate layer 21 The shrinkage stress of the layer 22 can also suppress the deformation of the liquid crystal layers. As a result, it is also possible to suppress the occurrence of rewinding of the optical layered body 73 with the adhesive layer.

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

3000≦E×t≦15000 (1)

The value of E×t in the above formula (1) is preferably 3500 [Pa. s] above, more preferably 4000 [Pa. s] above, and more preferably 4300 [Pa. s] or more, more 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 tends to be difficult to suppress the rewind of the optical laminate, and if it exceeds 15000 [Pa. s], the deformation in which the optical laminate is curled into an arc with the optical film 60 side as the inner side (hereinafter also referred to as "positive curl") tends to proceed too much, and it is difficult for the optical laminate to become a flat (flat) state. As a result, the optical laminate 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 higher, more preferably 1000 MPa or higher, may be 1500 MPa or higher, or may be 2000 MPa or higher. In addition, the storage elastic modulus E of the first adhesive layer 31 at 30° C. is usually 10000 MPa or less, more preferably 8000 MPa or less, and still more preferably 5000 MPa or less.

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 is preferably 15 μm or less, more preferably 10 μm or less, and even more preferably 8 μm or less, and It is usually 2.5 μm or more, preferably 3 μm or more, or 3.5 μm or more.

The optical laminate of this embodiment may have 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 as shown in FIG. 6(b) The adhesive layer-attached optical laminate 73 of the layer structure of the adhesive layer 33 can also be applied to the adhesive layer as shown in Figure 6 (a) On the side opposite to the second liquid crystal layer 22 of the adhesive layer 33 of the optical layered body 73, the optical layered body 72 (optical layered body) with an adhesive layer for protecting the second release layer 53 of the adhesive layer 33 ). In addition, the optical laminate of this 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 in this order as shown in FIG. 4(a). The optical laminate 70 (optical laminate) with the substrate layer of the layer 22 and the second substrate layer 21 may be peeled from the optical laminate 70 with the substrate layer as shown in FIG. 4(b) The optical laminate 71 (optical laminate) of the second base material layer 21 peeled from the base material layer. Each of these optical laminates (hereinafter, these are also generally referred to as "optical laminates"), when they are used in a form bonded to an optical display element (for example, the optical laminate 73 with an adhesive layer), Suppresses the occurrence of rewind, and can suppress the above-mentioned disadvantages that occur when bonding to an optical display element.

(Liquid crystal laminate)

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

The liquid crystal laminate of this embodiment may have 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 substrate layer 11, as shown in FIG. 2(a). The layer structure of the base layer 21 is the liquid crystal laminate 40 with base layer on both sides (liquid crystal laminate), and it may also be an attachment in which the first base layer 11 is peeled from the liquid crystal laminate 40 with base layers on both sides. The liquid crystal laminated body 41 (liquid crystal laminated body) of a single-sided base material layer (2nd (b)). The liquid crystal laminate 41 with a single-sided base layer, as shown in FIG. 2(b), has a first liquid crystal layer 12, a first adhesive layer 31, a second liquid crystal layer 22, and a second base layer 21 Layer structure. By using each of these liquid crystal laminates (hereinafter referred to as "liquid crystal laminates") to produce an optical laminate, it is possible to suppress the occurrence of rewinding, and to prevent the problems caused by bonding to the optical display element. The above-mentioned bad situation occurred.

(Method of manufacturing liquid crystal laminate and method of manufacturing optical laminate)

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 an optical laminated body, the liquid crystal laminated body 41 with a single-sided base material layer can be used, for example to manufacture an optical laminated body. Hereinafter, in the optical laminate 73 with an adhesive layer shown in FIG. 6(b), the second adhesive layer 32 is an adhesive layer formed by an adhesive as an example for description.

(Method of manufacturing liquid crystal laminate)

The manufacturing method of the liquid crystal laminate 41 with a single-sided base layer shown in Figure 2(b) includes preparing the first liquid crystal layer 10 with a base layer shown in Figure 1(a), and 1 Figure (b) shows the step of the second liquid crystal layer 20 with a substrate layer. 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 It is formed to be peelable from the first liquid crystal layer 12. The second liquid crystal layer 20 with a substrate layer has a second substrate layer 21 and a second liquid crystal layer 22 formed by polymerizing a polymerizable liquid crystal compound on the second substrate layer 21. The second substrate layer 21 It 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: on the first substrate layer 11, a composition for forming a liquid crystal layer containing a polymerizable liquid crystal compound is coated and dried, and then irradiated with ultraviolet rays. A step of 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 the composition for forming a liquid crystal layer containing a polymerizable liquid crystal compound and The step of drying and irradiating 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, perform the following steps: form an adhesive containing an adhesive composition for forming the first adhesive layer 31 of the adhesive hardened layer on the surface of the second liquid crystal layer 20 with the substrate layer on the side of the second liquid crystal layer 22 Step of the composition layer 31a. Through this step, a second liquid crystal layer 25 with a composition layer can be obtained (Figure 1(c)). The second liquid crystal layer 25 with the composition layer, as shown in FIG. 1(c), is a layer in which an adhesive composition layer 31a, a second liquid crystal layer 22, and a second base material 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 with a substrate layer.

On the adhesive composition layer 31a side of the second liquid crystal layer 25 with the obtained composition layer, the first liquid crystal layer 10 with the substrate layer is laminated on the first liquid crystal layer 12 side (Figure 1(d)), The first adhesive layer 31 is formed from the adhesive composition layer 31a, and a double-sided substrate layer-attached liquid crystal laminate 40 is produced (Figure 2(a)). The method of forming the adhesive composition layer 31a can be appropriately selected according to the type of the adhesive composition, but examples include active energy ray irradiation, heat treatment, and addition of a curing agent. As shown in Figure 2(a), the liquid crystal laminate layered body 40 with base layer on both sides has a first base layer 11, a first liquid crystal layer 12, a first adhesive layer 31, and a second liquid crystal layer sequentially laminated 22. And the second base material layer 21.

From the liquid crystal layer laminate 40 with base layer on both sides as shown in Fig. 2(a), the first base layer 11 is peeled without peeling the second base layer 21, thereby obtaining the result as shown in Fig. 2( b) The sequential base layer shown includes a first liquid crystal layer 12, a first adhesive layer 31, a second liquid crystal layer 22, and a second substrate layer 21. A single substrate layer liquid crystal laminate 41. The first adhesive layer 31 in the liquid crystal laminated body 40 with base layer on both sides shown in Fig. 2(a) and the liquid crystal laminated body 41 with a single base layer shown in Fig. 2(b) The cured adhesive layer, which is a cured product of a curable adhesive, preferably has rigidity that satisfies the relationship of formula (1) above. also, The absolute value of the curl amount of either the first liquid crystal layer 12 and the second liquid crystal layer 22 is 20 mm or less.

(Method of manufacturing optical laminate)

The manufacturing method of the adhesive layer-attached optical laminate 73 shown in Figure 6(b). First, a step of preparing a second adhesive layer 50 with a release layer is performed: on the first release layer 51, a step is formed to adhere The second adhesive layer 32 of the adhesive layer formed by the agent (Figure 3(a)). The step of preparing the second adhesive layer 50 with a release layer may also include the following steps: a step of coating the adhesive composition on the first release layer 51 and drying it to form the second adhesive layer 32. In addition, if necessary, the following step may also be provided: a step of covering the surface of the second adhesive layer 32 on the side opposite to the first peeling layer 51 with another peeling layer. The second adhesive layer 32 of the prepared second adhesive layer 50 with a release layer is bonded to the optical film 60 (Figure 3(b)), and the first release layer 51 is peeled off to obtain a second adhesive layer Optical film 61 (Figure 3(c)). The optical film 61 with a second adhesive layer, as shown in FIG. 3(c), is a layered optical film 60 and a second adhesive layer 32.

After that, the second adhesive layer 32 of the optical film 61 with the second adhesive layer, and the liquid crystal layer laminate 41 with a single substrate layer exposed by peeling off the first substrate layer 11 (Figure 2 (b) )) The first liquid crystal layer 12 (first exposed surface) is bonded to obtain an optical layered body 70 (optical layered body) with a substrate layer (Figure 4(a)). The liquid crystal laminated body 41 with a single base material layer only needs to have the structure shown in FIG. 2(b), and may be produced by the above-mentioned liquid crystal laminated body manufacturing method. The optical laminate 70 with a substrate layer, as shown in Figure 4(a), is laminated with 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 in this order. Layer 22, and the second substrate layer 21. By peeling the second base material layer 21 from the optical layered body 70 with a base material layer, an optical layered body 71 peeled off from the base material layer can be obtained (FIG. 4(b)).

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

The adhesive layer 33 side of the prepared adhesive layer 58 with a peeling layer, and the second liquid crystal layer 22 (the second liquid crystal layer 22) of the optical laminate 71 peeled from the base material layer exposed by peeling the second base material layer 21 The two exposed surfaces) are bonded together to obtain an optical laminate 72 with a release layer (Figure 6(a)). The optical laminate 72 with a release layer, as shown in Figure 6(a), is laminated with 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 this order 22. The adhesive layer 33 and the second peeling 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 resulting optical laminate 73 with an adhesive layer can be bonded to the adhesive layer 33 and optical display elements to form an image display panel.

The method for manufacturing the liquid crystal laminate (Figure 2) and the method for manufacturing the optical laminate (Figures 4 and 6) are on the first base material layer 11 or the second base material 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 laminate 40 with base material layers on both sides shown in Fig. 2(a), the base material layer shown in Fig. 4(a) When the optical laminate 70 peels off 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 hardened is released. In this embodiment, since the absolute value of the curl amount of the first liquid crystal layer 12 and the second liquid crystal layer 22 is 20 mm or less, even if the first base material layer 11 or the second base material layer 21 is peeled off, the shrinkage stress is relieved. It is estimated that the deformation amounts of the first liquid crystal layer 12 and the second liquid crystal layer 22 are 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 from the base material layer is not easily deformed. Thereby, the optical layered body 71 peeled from the substrate layer, or the optical layered body 72 with a peeling layer or the optical layered body 73 with an adhesive layer shown in Figure 6 (a) and (b), can be Suppress the occurrence of rewind.

In addition, since the first adhesive layer 31 is an adhesive cured layer and has rigidity in relation to the above-mentioned formula (1), the optical layered body 71 peeled off the base layer, the optical layered body 72 with a peeling layer, and the attached The optical layered body 73 of the adhesive layer can suppress excessive positive curling, 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 release layer used in the production of a liquid crystal laminate or an optical laminate are used The layer 50, the adhesive layer 58 with a release layer, the optical film 60, and the optical film 61 with the second adhesive layer are preferably long-sized films, and it is preferable to make them equal to continuous Each step is carried out under transportation. The width direction W is usually a direction (TD direction) orthogonal to the longitudinal direction (conveying direction, MD direction) of the film.

(Modification)

The liquid crystal laminated body, the optical laminated body, and the manufacturing method of these of this embodiment can also be changed to the modification shown below. In addition, the above-mentioned embodiment and the modification examples shown below may be combined arbitrarily.

(Modification 1)

In the above, the case where the second adhesive layer 32 included in the optical laminate is an adhesive layer was explained, but it is not limited to this. For example, the second adhesive layer 32 may also be an adhesive cured layer composed of a cured product of a curable adhesive. In this case, instead of forming the second adhesive layer on the first peeling layer 51, the first base material layer 11 of the liquid crystal laminate 41 with a single-sided base material layer is peeled off on the optical film 60 and exposed At least one of the first liquid crystal layer 12 (first exposed surface) may form an adhesive composition layer containing the adhesive composition.

(Modification 2)

In the above, the following case is taken as an example for description: the second liquid crystal layer used on the second liquid crystal layer 22 side of the second liquid crystal layer 20 with a base material layer is provided with an adhesive composition layer 31a. 25 (Figure 1 (c)), the first liquid crystal layer 12 of the first liquid crystal layer 10 with a substrate layer is laminated on the adhesive composition layer 31a, but as long as the first liquid crystal layer with a substrate layer is available 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 layer laminate with double-sided base material layer 40 (the first 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 10 with a substrate layer, and the second liquid crystal layer 20 with a substrate 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 the first liquid crystal layer 12 side of the first liquid crystal layer 10 with a base material layer and the second liquid crystal layer 22 side of the second liquid crystal layer 20 with a base material layer may form an adhesive composition layer 31a.

(Modification 3)

In the above, the following case is taken as an example for description: using the second adhesive layer 50 with a release layer shown in Figure 3(a), the second adhesive layer 32 is provided on the optical film 60 to obtain the second adhesive layer The optical film 61 (Figure 3(c)), the second adhesive layer 32 of the optical film 61 with a second adhesive layer, and the first liquid crystal layer 12 of the liquid crystal laminate 41 with a single-sided substrate layer Bonding, but as long as it can be laminated on the exposed surface (first liquid crystal layer 12) of the liquid crystal laminate 41 with a single-sided base material layer exposed by peeling the first base material layer 11 through the second adhesive layer 32 The optical film 60 is sufficient, and it is not limited to this. For example, the second adhesive layer 50 with a release layer shown in Fig. 3(a) can also be used to prepare on the exposed surface (first liquid crystal layer 12) of the liquid crystal laminate 41 with a single-sided base layer A second adhesive layer-attached liquid crystal laminate laminate is provided with a second adhesive layer 32, and an optical film 60 is laminated on the second adhesive layer 32. In this case, the liquid crystal laminate with the second adhesive layer, as long as It suffices to have 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 in this order, and the second adhesive layer 32 and the first liquid crystal layer 12 The surface on the opposite side may have a first peeling layer 51.

Although the above description has been directed to the embodiments of the present invention and its modifications, the present invention is not limited to these embodiments and its modifications. For example, it is also possible to combine the steps of the above embodiments and its modifications. . Hereinafter, each member used in the embodiment will be described in detail.

(Optical Film)

The optical film includes a thermoplastic resin film composed of a thermoplastic resin. It is a film with optical functions. For example, it can be a polarizer, a polarizer with a protective layer formed on at least one side of the polarizer, and a polarizer. Polarizing plate with protective film, reflective film, semi-transmissive reflective film, brightness enhancement film, optical compensation film, anti-glare functional film, etc. with protective film on at least one area. The optical film may be an optical film with a one-layer structure or a multilayer structure with two or more layers.

The rewind generated by the optical laminate, if the thickness or rigidity of the optical film contained in the optical laminate is smaller, it is presumed that it is more likely to be affected by the release of the shrinkage stress caused by the liquid crystal layer. In addition, the greater the thickness or rigidity of the base layer, the greater the shrinkage stress remaining in the liquid crystal layer, and it is estimated that the greater the effect of the shrinkage stress released when the base layer is peeled off. Therefore, the thickness of the optical film is preferably 2 μm or more and 500 μm or less. The thickness of the optical film may be 10 μm or more, and it may be 350 μm or less, 200 μm or less, or 150 μm or less.

(Polarizer)

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

Specific examples of the polarizer composed of a single-layer resin film include polyvinyl alcohol (hereinafter referred to as "PVA") film, partially acetalized PVA film, and ethylene. Ethyl acetate copolymer is a hydrophilic polymer film such as a partially acetalized film, which is dyed or extended with dichroic substances such as iodine or dichroic dye; dehydration treatment of PVA or polyvinyl chloride Polyolefin-based alignment films such as hydrochloric acid-depleted products. Because of its excellent optical properties, it is preferable to use a polarizer obtained by uniaxially stretching a PVA-based film after dyeing with iodine.

Specific examples of the polarizer composed of a single-layer resin film include polyvinyl alcohol (hereinafter referred to as "PVA") film, partially acetalized PVA film, and ethylene. Ethyl acetate copolymer is a hydrophilic polymer film such as a partially acetalized film, which is dyed or extended with dichroic substances such as iodine or dichroic dye; dehydration treatment of PVA or polyvinyl chloride Polyolefin-based alignment films such as hydrochloric acid-depleted products. Because of its excellent optical properties, it is preferable to use a polarizer obtained by uniaxially stretching a PVA-based film after dyeing with iodine.

The degree of saponification of the polyvinyl alcohol resin is usually about 85 to 100 mol%, preferably 98 mol% or more. 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 resin is usually about 1,000 to 10,000, preferably about 1,500 to 5,000.

The degree of saponification of the polyvinyl alcohol resin is usually about 85 to 100 mol%, preferably 98 mol% or more. 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 resin is usually about 1,000 to 10,000, preferably about 1,500 to 5,000.

Other methods for manufacturing polarizers include, for example, those that include the following steps: first, prepare a substrate film, apply a solution of resin such as polyvinyl alcohol resin on the substrate film, remove the solvent and dry the substrate film. The step of forming a resin layer. In addition, a primer layer may be formed in advance on the surface of the base film on which the resin layer is formed. A resin film such as PET can be used as the base film. The material of the primer layer includes, for example, a resin used in a polarizer to crosslink a hydrophilic resin.

Then, if necessary, adjust the amount of solvent such as moisture in the resin layer, and then uniaxially stretch the base film and the resin layer, and then dye the resin layer with a dichroic dye such as iodine so that the dichroic dye is adsorbed and aligned In the resin layer. Then, 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 off the boric acid aqueous solution is performed. Thereby, the resin layer with the dichroic dye adsorbed and aligned, that is, the film of the polarizer is manufactured. Well-known methods 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 uniaxial stretching in the plural stages. The base film and resin layer can be uniaxially stretched in the MD direction (film conveying direction). In this case, it can be uniaxially stretched between rolls 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 conveying direction), and in this case, the so-called tenter method can also be used. In addition, the stretching of the base film and the resin layer may be dry stretching in which it is stretched in the air, or 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 4 times or more, preferably 5 times or more, and particularly preferably 5.5 times or more. The upper limit of the stretch magnification is not particularly limited, but from the viewpoint of suppression of breakage, it is preferably 8 times or less.

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

The method for producing a polarizer of a cured film in which a dichroic dye is aligned with a polymerizable liquid crystal compound to polymerize the polymerizable liquid crystal compound can be, for example, the following method. The base film is coated with a polymerizable liquid crystal compound and two The composition for forming a polarizer of a chromatic dye is a method of polymerizing and curing a polymerizable liquid crystal compound while maintaining a liquid crystal state to form a polarizer. Therefore, the obtained polarizer exists in the state laminated on the base film, and the polarizer with the base film can also be used as an optical film. Alternatively, the base film may be made into a polarizer with a base film that can be peeled off from the polarizer, and then laminated on the single-sided base layer-attached liquid crystal laminate 41 via the second adhesive layer 32, or laminated on After the second adhesive layer 50 with a peeling layer is attached, 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。 The dichroic dye can be a dye having a property that the absorbance in the long axis direction of the molecule is different from the absorbance in the short axis direction, for example, a dye having an absorption maximum wavelength (λ max) in the range of 300 to 700 nm. Such dichroic pigments include acridine pigments,

Among pigments, cyanine pigments, naphthalene pigments, azo pigments, anthraquinone pigments, etc., azo pigments are preferred. Examples of azo dyes include monoazo dyes, bisazo dyes, ginsenochromes, tetrazo dyes, stilbene azo dyes, and the like, and bisazo dyes and ginseno dyes are more preferred.

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. Regarding 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 Bulletin No. 102479 and Japanese Patent Application Publication No. 2017-83843. In addition, the polymerizable compound may be the same as the compound exemplified as the polymerizable liquid crystal compound used to prepare the first liquid crystal layer and the second liquid crystal layer described later. Regarding the method of forming a polarizer using the composition for forming a polarized photon, the method exemplified in the above publication can also be adopted.

The thickness of the polarizer is preferably 2 μm or more, more preferably 3 μm or more. In addition, the thickness of the aforementioned polarizer is 25 μm or less, preferably 15 μm or less, more preferably 13 μm or less, and still more preferably 7 μm or less. In addition, the above upper limit and lower limit can be combined arbitrarily. The thinner the thickness of the polarizer, the lower the rigidity, and the more easily affected by the shrinkage stress of the first liquid crystal layer or the second liquid crystal layer. Therefore, when a polarizer with a small thickness is used as an optical film, it is better to use 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 well-known adhesive layer or a protective layer can be laminated on one side or both sides of the polarizer to make a polarizing plate. The 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 a film formed of a thermoplastic resin with excellent transparency, mechanical strength, thermal stability, moisture barrier properties, 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 sulfite resins; polysulfite resins; Polycarbonate resin; polyamide resin such as nylon or aromatic polyamide resin; polyimide resin; polyethylene, polypropylene, ethylene. Polyolefin resins such as propylene copolymers; cyclic polyolefin resins and cyclic polyolefin resins with a norbornene structure (also known as norbornene resins); (meth)acrylic resins; polyarylate resins; polystyrene resins; Polyvinyl alcohol resin, and mixtures of these. When there are protective films on the two areas of the polarizer, the resin composition of the two protective layers may be the same or different. In addition, in this specification, "(meth)acrylic acid" means either acrylic acid or methacrylic acid. "(Meth)" such as (meth)acrylate also has the same meaning.

The film formed of thermoplastic resin can be surface treated (for example, corona treatment, etc.) in order to improve the adhesion to the polarizer made of PVA-based resin and dichroic material, or it can form a primer layer (Also known as the primer layer) and other thin layers.

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 . For 24hr, in a high temperature environment, the polarizer 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 time-dependent changes in the curl of the polarizer. The moisture permeability of the protective layer at a temperature of 40°C and a humidity of 90%RH is preferably 1000g/m ² . Less than 24hr, more preferably 100g/m ² . Less than 24hr, more preferably 10g/m ² . Less than 24hr. 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 the 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 polarizer. Here, the so-called rigidity is defined as the tensile elastic modulus of the film used in 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, use a protective layer of a cellulose polymer represented by cellulose triacetate, preferably with an elastic modulus in the range of 3000 to 5000 MPa at 23°C, and use 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 4000 MPa, and the protective layer of cycloolefin polymer having a norbornene structure is used. The elastic modulus at 23°C is preferably in the range of 2000 to 4000 MPa. For the outer protective layer, it is preferable to use an acrylic polymer or a polyolefin-based polymer from the viewpoint of the above-mentioned moisture permeability and rigidity, and it is particularly preferable to use a cycloolefin-based polymer. The modulus of elasticity at 23°C can be measured in accordance with JIS K 7113.

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

The stretching direction of the stretching treatment may be the length direction of the unstretched resin, the direction orthogonal to the length direction, or the direction oblique to the length direction. In the case of uniaxial stretching, the unstretched resin can be stretched in any of these directions. Biaxial stretching may be simultaneous biaxial stretching in which two stretching directions are simultaneously stretched in these directions, or may be sequential biaxial stretching in which stretching in a predetermined direction followed by stretching in other directions.

The stretching treatment can be carried out, for example, by using two or more pairs of rolls with increasing circumferential velocity on the downstream side to stretch in the longitudinal direction, or to clamp the both ends of the unstretched resin in the longitudinal direction with clamps. Stretching in the orthogonal direction, etc. At this time, by adjusting the thickness of the thermoplastic resin after stretching, 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), Re(550) represent the in-plane retardation value at the measurement wavelength of 590nm, 450nm, 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 values measured in an environment with a temperature of 23°C and a relative humidity of 55%.

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

(S1) Re=(nx-ny)×d

(S2) Rth=[{(nx+ny)/2}-nz]×d

The outer protective layer is preferably a stretched thermoplastic resin satisfying the above formulas (1) to (3). Moreover, the outer protective layer is preferably attached to a polarizer having a slow axis obliquely 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 It is 45±10° or 135±10° to fit 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 the light in the fast axis direction and the phase of the light in the slow axis direction. If the optical laminate of this embodiment is used in an optical display element, the light emitted through the optical laminate can be made Become circularly polarized light. Therefore, when the optical laminate of this embodiment is used in a display device of an optical display element, the display device has excellent visibility even when viewing a displayed image through polarized sunglasses.

The thickness of the protective layer is preferably 3 μm or more, more preferably 5 μm or more. In addition, the thickness of the protective layer is preferably 50 μm or less, more preferably 30 μm or less. In addition, the above upper limit and lower limit can be combined arbitrarily. The thinner the thickness of the polarizing plate, the smaller the rigidity, and the more susceptible to the shrinkage stress of the first liquid crystal layer or the second liquid crystal layer. Therefore, when a polarizing plate with a small thickness is used as an optical film, it is better to use 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 on the opposite side of the polarizer may also have a surface treatment layer, for example, a hard coat layer, an anti-reflection layer, an anti-adhesion layer, an anti-glare layer, a diffusion layer, etc. 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 coating 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 silicone can be applied to the surface of the protective layer. Wait to form. The purpose of the anti-reflection layer is to prevent the reflection of light from outside the surface of the polarizing plate, which can be achieved by forming an anti-reflection film based on the prior art. In addition, 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 light outside the surface of the polarizer and hinder the visual recognition of the transmitted light of the polarizer. For example, it can be roughened by sandblasting or embossing, or by blending transparent particles, etc. , The surface of the protective layer is provided with an uneven structure to form. The transparent particles used to impart a fine concave-convex 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, and an average particle diameter of 0.5 to 50 μm . Antimony oxide and other conductive inorganic particles, crosslinked or uncrosslinked polymers, and other organic particles. The content of the transparent fine particles is generally 2 to 50 parts by mass, preferably 5 to 25 parts by mass, relative to 100 parts by mass of the resin forming the layer of the fine concavo-convex structure. The anti-glare layer may also be a diffusion layer (viewing angle expansion function, etc.) that also functions as a diffusion layer that diffuses the transmitted light of the polarizing plate to expand the viewing angle.

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. Furthermore, it is preferably 10 μm or less, more preferably 8 μm or less. If the thickness is less than 0.5 μm , it tends to be difficult to effectively prevent damage to the surface of the polarizing plate. In addition, if the thickness exceeds 10 μm , it will become difficult to suppress reverse curling of the polarizing plate due to increased curing shrinkage.

When the thickness of the polarizing plate is 2 μm or more and 300 μm or less, the optical laminate of the above-mentioned embodiment and the manufacturing method thereof are preferable. The thickness of the polarizing plate may be 10 μm or more, and may be 150 μm or less, 120 μm or less, or 80 μm or less.

(Polarizing plate with protective film)

The polarizing plate is usually made into a polarizing plate of poly-protective film due to its single-area protective film. The protective film contains a resin film for the protective film and an adhesive layer for the protective film laminated on the resin film. The thickness of the protective film can be, for example, 30 to 200 μm , preferably 40 to 150 μm , more preferably 50 to 120 μm .

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

The adhesive constituting the adhesive layer for the protective film can be the same as the adhesive constituting the adhesive layer described later. In addition, the protective film can form an adhesive layer by coating the adhesive composition on the surface of the resin film for the protective film and drying. If necessary, in order to improve the adhesion of the adhesive-coated surface of the resin film for the protective film, surface treatment (for example, corona treatment) can be applied, and a primer layer (also called a primer layer) can also be formed. Floor. Moreover, if necessary, you may have a peeling layer for covering the surface of the adhesive layer for protective films on the opposite side to the resin film side for protective films. The peeling layer can be peeled off at an appropriate timing when bonding to the polarizing plate.

In the manufacturing steps of the polarizing plate with protective film attached to the protective film, by imparting a difference in tension or a difference in circumferential velocity, a positive curl can also be provided in the longitudinal direction of the polarizing plate with a protective film. Therefore, in the optical laminated body and the optical laminated body manufacturing method of the above-mentioned embodiment, when a polarizing plate with a protective film is used as an optical film, the polarizing plate with a protective film will be By imparting a positive curl, it is expected that the back curl of the optical laminate can be suppressed 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 The 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 "adhesive agent" refers to the one that sticks itself to an adherend such as an optical film or a liquid crystal layer to exhibit adhesiveness, so-called a pressure-sensitive adhesive agent. In addition, the active energy ray-curable adhesive described later can adjust the degree of crosslinking or adhesion by irradiating energy rays. As mentioned above, the second adhesive layer can also be an adhesive layer.

The adhesive can be used without any special restrictions, which is conventionally known and has excellent optical transparency. As the adhesive, for example, adhesives having matrix polymers such as acrylic, urethane, silicone, and polyvinyl ether can be used. In addition, it may be an active energy ray-curable adhesive, a thermosetting adhesive, or the like. Among these, it is preferable to use an acrylic resin excellent in transparency, adhesive strength, releasability (hereinafter, also referred to as remanufacturability), weather resistance, heat resistance, etc. as the adhesive 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 the 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") as a main component (for example, containing more than 50% of these). The term "derived from" in this specification means that the chemical structure changes due to the polymerization of compounds such as alkyl (meth)acrylate.

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

The (meth)acrylate represented by formula (I) includes, for example, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, and isopropyl (meth)acrylate , N-butyl (meth)acrylate, isobutyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, (meth)propylene Isohexyl acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-heptyl (meth)acrylate And isononyl ester, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-dodecyl (meth)acrylate, cyclohexyl (meth)acrylate, isocamyl (meth)acrylate , Stearyl (meth)acrylate, tertiary butyl (meth)acrylate, etc. Specific examples of the alkoxy-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 also contain structural units derived from monomers other than structural unit (I). The structural unit derived from other monomers may be one type or two or more types. Other monomers that may contain a (meth)acrylate polymer include, for example, monomers having polar functional groups, monomers having aromatic groups, and acrylamide-based monomers.

The monomer having a polar functional group includes, for example, (meth)acrylate having a polar functional group. The polar functional group can be combined with, for example, a hydroxyl group, a carboxyl group, a substituted amino group, an unsubstituted amino group, and the like. Examples of polar functional groups include heterocyclic groups such as epoxy groups.

The content of the structural unit derived from the monomer having a polar functional group in the (meth)acrylate polymer is preferably 20 parts by mass or less relative to 100 parts by mass of the total structural unit of the (meth)acrylate polymer , It is more preferably not less than 0.1 part by mass and not more than 20 parts by mass, still more preferably not less than 0.1 part by mass and not more than 10 parts by mass, particularly preferably not less than 0.5 part by mass and not more than 10 parts by mass.

Monomers having aromatic groups include, for example, having one (meth)acrylic acid group and more than one aromatic ring (for example, benzene ring, naphthalene ring, etc.) in the molecule, and having a phenyl group and a phenoxyethyl group. , Or benzyl (meth)acrylate.

(Meth) acrylic ester polymers derived from monomers with aromatic groups The content of sites, relative to 100 parts by mass of the total structural unit of the (meth)acrylate polymer, is preferably 50 parts by mass or less, more preferably 4 parts by mass or more and 50 parts by mass or less, and still more preferably 4 parts by mass or more 25 parts by mass or less.

The acrylamide-based monomers include, for example, N-(methoxymethyl)acrylamide, N-(ethoxymeth)acrylamide, N-(propoxymethyl)acrylamide, N -(Butoxymeth)acrylamide, N-(2-methylpropoxymeth)acrylamide, etc. By containing these structural units, the bleeding of additives such as antistatic agents described later can be suppressed.

Furthermore, structural units derived from monomers other than the structural unit (I) may include structural units derived from styrene-based monomers, structural units derived from vinyl-based monomers, and those derived from multiple ( The structural unit of the monomer of meth)acryloyl group.

The weight average molecular weight of the (meth)acrylic resin (1) (hereinafter, also simply referred to as "Mw") is preferably 500,000 to 2.5 million. 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 2.5 million or less, the workability of the coating liquid containing the adhesive composition during coating 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 referred to as "Mn") is usually 2-10. In this specification, the "weight average molecular weight" and "number average molecular weight" are the polystyrene conversion values measured by the gel permeation chromatography (GPC) method.

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

Considering both the adhesion and durability, (meth)acrylic resin (1) The glass transition temperature is preferably -10°C to -60°C. In addition, the glass transition temperature can be measured with a differential scanning calorimetry (DSC).

The (meth)acrylic resin (1) may contain two or more (meth)acrylate polymers. Such (meth)acrylate polymers include, for example, those having a structural unit (I) derived from the aforementioned (meth)acrylate as a main component, and a lower molecular weight in the range of 50,000 to 300,000 in weight average molecular weight.的(meth)acrylate polymer.

(Crosslinker (2))

The adhesive composition forming the adhesive layer preferably contains a crosslinking agent (2). The cross-linking agent (2) includes, for example, conventional cross-linking agents (for example, isocyanate compounds, epoxy compounds, aziridine compounds, metal chelating compounds, peroxides, etc.), especially those composed of adhesives From the viewpoints of the period or the crosslinking speed, an isocyanate-based compound is preferred.

The isocyanate compound is preferably a compound having at least two isocyanate groups (-NCO) in the molecule, and examples include aliphatic isocyanate compounds (e.g., hexamethylene diisocyanate, etc.) and alicyclic isocyanate compounds ( For example, isophorone diisocyanate, etc.), hydrogenated xylene diisocyanate, hydrogenated diphenylmethane diisocyanate, aromatic isocyanate compounds (such as phenylmethylene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate) , Naphthalene diisocyanate, triphenylmethane, triisocyanate, etc.). In addition, the crosslinking agent (2) may be an adduct (adduct) caused by the polyol compound of the above isocyanate compound [for example, an adduct caused by glycerin, trimethylolpropane, etc.], Polyurethane prepolymerization of trimeric isocyanate, diurea compound, polyether alcohol, polyester polyol, acrylic polyol, polybutadiene polyol, polyisopentene polyol, etc. for addition reaction Derivatives such as isocyanate compounds of physical type. The crosslinking agent (2) can be used alone or in combination of two or more. Among these, from the viewpoint of durability, phenylmethylene diisocyanate, xylene diisocyanate, and hexamethylene diisocyanate are preferred. Isocyanates and these polyol compounds or these trimeric isocyanate compounds.

The ratio of the crosslinking agent (2) relative to 100 parts by mass of the (meth)acrylic resin (1) 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 . If it is less than the above upper limit value, it is advantageous for the improvement of durability, and if it is more than the above lower limit value, the generation of gas can be suppressed, and it is advantageous for the improvement of reproducibility.

(Silane compound (3))

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

The silane compound (3) includes, for example, vinyl trimethoxy silane, vinyl triethoxy silane, vinyl ginseng (2-methoxyethoxy) silane, 3-glycidoxy propyl trimethoxy Silane, 3-glycidoxypropyl triethoxy silane, 3-glycidoxy propyl methyl dimethoxy silane, 3-glycidoxy propyl ethoxy dimethyl silane , 2-(3,4-Epoxycyclohexyl) ethyl trimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacrylic acid Oxypropyl trimethoxysilane, 3-mercaptopropyl trimethoxysilane, etc.

In addition, the silane compound (3) may also include an oligomer derived from the above-mentioned 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, and more preferably, relative to 100 parts by mass of the (meth)acrylic resin (1) 0.05 to 2 parts by mass, and more preferably 0.1 to 1 part by mass. When the content of the silane compound (3) is 0.01 parts by mass or more, it is easy to improve the adhesion of the adhesive layer and the adherend such as the optical film or the liquid crystal layer. If the content is 10 parts by mass or less, the exudation of the silane compound (3) from the adhesive layer can be suppressed.

(Other ingredients (4))

The adhesive composition forming the adhesive layer may contain single or two or more of the following additives as other components (4), for example, antistatic agents such as ionic compounds, solvents, crosslinking catalysts, and viscosity imparting Resin (tackifier), plasticizer, weather stabilizer, softener, dye, pigment, inorganic filler, resin other than acrylic resin and other additives.

(Active energy ray hardening adhesive)

It is also useful to mix multifunctional acrylate and other ultraviolet curable compounds in the adhesive composition, and irradiate ultraviolet rays to harden after forming the adhesive layer to make a harder adhesive layer, and it can be cured with active energy rays Type adhesive. "Active energy ray curable adhesive" has the property of being cured by irradiation of energy rays such as ultraviolet rays or electron beams. Since the active energy ray hardening adhesive has adhesiveness before the energy ray is irradiated, it has an adherend that can adhere to the optical film or liquid crystal layer, and can adjust the density of the hardening by the energy ray irradiation Adhesive with 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 or photosensitizer, etc. can be adjusted as needed.

The storage elastic modulus of the adhesive layer is preferably 0.10 to 10.0 MPa, more preferably 0.15 to 5.0 MPa at 23°C. If the storage modulus of elasticity at 23°C is 0.1 MPa or more, it is possible to suppress defects such as peeling during temperature changes, so it is preferable. In addition, if it is 10.0 MPa or less, it is less likely to cause a decrease in durability due to a decrease in adhesive force, which is preferable. In addition, the storage elastic modulus of the adhesive layer can be measured by the method described in the implementation force.

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

(Adhesive hardened layer)

The adhesive hardening layer refers to a layer formed by hardening the curable component in the adhesive composition. The adhesive composition used to form the hardened layer of the adhesive is an adhesive other than a pressure-sensitive adhesive (adhesive), and examples include water-based adhesives and active energy ray-curable adhesives. Examples of the water-based adhesive include an adhesive obtained by dissolving or dispersing polyvinyl alcohol-based resin in water. Examples of the active energy ray curable adhesive include a solvent-free active energy ray curable adhesive containing a curable compound that is cured by irradiation with active energy rays such as ultraviolet rays, visible light, electron beams, and X-rays. By using a solvent-free active energy ray curable adhesive, the adhesion between layers can be improved. In contrast, if a solvent (especially an organic solvent) is contained in the active energy ray curable adhesive, even if the curable components contained in the adhesive are the same, sufficient adhesion cannot be obtained. When cutting the optical laminate When it is a predetermined size, it is easy to cause defects such as peeling at the end. In addition, since it is necessary to add a step of drying the solvent, additional shrinkage stress is applied due to heat, and there is a possibility that the optical layered body is likely to be reversed.

When using a solvent-free active energy ray curable adhesive containing a curable compound that is cured by active energy ray irradiation, the storage elastic model is an index showing the hardness of the active energy ray curable adhesive after curing The rigidity of the number multiplied by the thickness is mostly higher than the rigidity of the water-based adhesive after curing. In order to increase the rigidity of the adhesive hardening 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 hardening adhesive.

Since it exhibits good adhesiveness, the active energy ray curable adhesive is preferably one or both of a curable compound containing a cationic polymer and a curable compound with radical polymerization properties. The active energy ray curable adhesive may further contain a cationic polymerization initiator or a radical polymerization initiator that initiates the curing reaction of the above-mentioned curable compound.

Cationic polymerizable curable compounds, for example, epoxy compounds (in the molecule A compound having one or more epoxy groups), or an oxetane compound (a compound having one or more oxetane in the molecule), or a combination of these.

Examples of radically polymerizable curable compounds include (meth)acrylic compounds (compounds having one or more (meth)acryloxy groups in the molecule), radically polymerizable compounds with double Bond to other vinyl compounds, or combinations of these.

The active energy ray curable adhesive may optionally contain a sensitizer. By using a sensitizer, the reactivity can be improved, and the mechanical strength and adhesive strength of the adhesive layer can be further improved. As sensitizers, well-known ones can be used appropriately. When the sensitizer is formulated, its 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 curable adhesives, if necessary, may contain ion trapping agents, antioxidants, chain transfer agents, tackifiers, thermoplastic resins, fillers, flow regulators, plasticizers, defoamers, antistatic agents, Additives for leveling agents and solvents.

It is also possible to form the adhesive composition layer by coating the adhesive composition on the joint surface of the first liquid crystal layer with a substrate layer or the second liquid crystal layer with a substrate layer. The coating method can be used using die coater, comma coater, reverse roll coater, gravure coater, bar coater, wire bar coater, knife coater, gas General coating technology such as knife coater.

The drying method when using the water-based adhesive is not particularly limited. For example, a hot air dryer or an infrared dryer can be used.

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

In the case where the adhesive composition layer is cured by ultraviolet irradiation, the intensity of ultraviolet light irradiation is determined by the composition of the adhesive composition and is not particularly limited, but 10 to 1000 mW/cm ^{2 is} preferred. 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 , the heat radiated from the light source and the heat generated during the polymerization of the adhesive composition The resulting hardened layer of the adhesive has the possibility of yellowing. In addition, there is a possibility that the heat radiated from the light source generates greater shrinkage stress. 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 the wavelength of 400 nm, and still more preferably the wavelength The intensity in the wavelength region of 280 to 320 nm. It is preferably set to irradiate with such light irradiation intensity once or several times so that the cumulative light quantity is 10 mJ/cm ² , preferably 100 to 1000 mJ/cm ² , more preferably 200 to 600 mJ/cm ² . If the cumulative amount of light to the adhesive composition does not reach 10 mJ/cm ² , the production of active species derived from the polymerization initiator will be insufficient, and the curing of the adhesive composition layer will be insufficient. If the accumulated light amount exceeds 1000 mJ/cm ² , the irradiation time becomes very long, which is not conducive to improving productivity. In addition, there is a possibility that the heat radiated from the light source may generate greater shrinkage stress. 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, 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 can be selected as long as it can be coated by any coating method, and the viscosity at a temperature of 25°C is between 10 and 1000 mPa. The range of sec is preferably, more preferably 20 to 500 mPa. The range of sec. If the viscosity is too small, it tends to be difficult to form a hardened layer of the adhesive with the 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 is difficult to obtain a uniform coating film without deviation. The so-called viscosity here is After adjusting the temperature of the adhesive to 25°C with an E-type viscometer, the value measured at 10 rps.

(Adhesive layer with peeling layer)

The 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 treatment surface of the release layer and used It is dried to form an adhesive layer. If necessary, the adhesive layer with the release layer may also have another release layer for covering and protecting the surface of the adhesive layer on the side opposite to the release layer. The peeling layer and other peeling layers can be peeled off at an appropriate time.

(Peeling layer)

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

The peeling layer can be peeled from the adhesive layer, and the size of the peeling force between the peeling layer and the adhesive layer must be determined by considering the order of peeling the peeling layer. The above-mentioned peeling force is prepared by preparing a test piece (with a size of 200 mm in length and 25 mm in width) for measurement with an adhesive layer on the peeling layer, and attaching it to glass of appropriate size, using a high-pressure retort (AGS-50NX) manufactured by Shimadzu Corporation. The peeling layer that was partially peeled off was sandwiched with the glass so as to form the peeling starting point, and the peeling strength measured when the peeling layer was peeled in a direction of 180° at a speed of 300 mm/min was regarded as the peeling force. The peeling force between the peeling layer and the adhesive layer is preferably 0.01 to 0.20 N/25 mm, more preferably 0.02 to 0.10 N/25 mm, and still more preferably 0.02 to 0.06 N/25 mm. If it is less than 0.01N/25mm, there is a risk of floating between the peeling layer and the adhesive layer during transportation. In addition, if it exceeds 0.20N/25mm, the adhesion between the release layer and the adhesive layer will be 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 layers that do not want to peel off There is a possibility of peeling (for example, peeling between the layer bonded on the side opposite to the peeling layer of the adhesive layer, and the adhesive layer).

(Liquid crystal layer)

The first liquid crystal layer and the second liquid crystal layer (hereinafter, both are also collectively referred to as "liquid crystal layer") are hardened 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 with respect 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 with respect to the plane of the substrate layer is defined as vertical Alignment. 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 orthogonal to the optical axis is the circular direction, that is, the refractive index in the two directions is Equal direction.

The polymerizable liquid crystal compound may, for example, be a rod-shaped polymerizable liquid crystal compound or a disc-shaped 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 consistent 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 orthogonal to the disc surface of the polymerizable liquid crystal compound.

In order to make the liquid layer formed by polymerizing the polymerizable liquid crystal compound exhibit an in-plane phase difference, the polymerizable liquid crystal compound can be aligned in an appropriate direction. When the polymerizable liquid crystal compound is in the shape of a rod, the optical axis of the polymerizable liquid crystal compound is aligned at a level relative to the plane of the substrate layer to exhibit in-plane phase difference. At this time, the optical axis direction and the slow axis direction Consistent. The polymerizable liquid crystal compound is a disc In this case, the in-plane phase difference is exhibited by aligning the optical axis of the polymerizable liquid crystal compound at a level relative to the plane of the substrate layer. At this time, the optical axis is orthogonal to the slow axis. The alignment state of the polymerizable liquid crystal compound can be adjusted by 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 polymerizable group refers to a group related to a polymerization reaction, and a photopolymerizable group is preferred. Here, the term "photopolymerizable group" refers to a group that can participate in a polymerization reaction by a living radical or acid generated from a photopolymerization initiator described later. Examples of polymerizable groups include vinyl, vinyloxy, 1-chlorovinyl, isopropenyl, 4-vinylphenyl, propyleneoxy, methacryloxy, oxirane, and oxygen heterocycles. Butyl and so on. Among them, propyleneoxy group, methacryloxy group, ethyleneoxy group, oxirane group and oxetanyl group are preferred, and propyleneoxy group is more preferred. The liquid crystallinity possessed by the polymerizable liquid crystal compound can be either a thermotropic liquid crystal or a fusogenic liquid crystal. If the thermotropic liquid crystal is classified in order, it can be a nematic liquid crystal or a smectic liquid crystal. .

A rod-shaped polymerizable liquid crystal compound or a disc-shaped polymerizable liquid crystal compound can be used. Known ones can be used. Japanese Patent Application Publication No. 2015-163937, Japanese Patent Application Publication No. 2016-42185, International Publication No. 2016/158940, Those exemplified in Japanese Patent Application Publication No. 2016-224128.

The liquid crystal layer may have a one-layer structure or a multilayer structure of two or more layers. When it has a multilayer structure of two or more layers, when preparing a liquid crystal layer with a substrate layer described later, it is sufficient to form a liquid crystal layer of a multilayer structure of two or more layers on the substrate layer. When the liquid crystal layer is a one-layer structure, the thickness of the liquid crystal layer is preferably 0.3 μm or more, or 1 μm or more, usually 10 μm or less, 5 μm or less, more preferably 3 μm or less . When the liquid crystal layer has a multilayer structure of two or more layers, the thickness of the liquid crystal layer is preferably 0.5 μm or more, or 1 μm or more, usually 10 μm or less, or 5 μm or less, more preferably Below 3 μ m. From the viewpoint of contributing to the thinning of the entire polarizing plate and effectively suppressing the occurrence of rewind, the thickness of the liquid crystal layer is preferably 5 μm or less, more preferably 3 μm or less.

(Liquid crystal 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 "liquid crystal layer with a substrate layer") can be prepared by the following method. 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 hardened 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, only needs to be coated on the alignment layer. When the liquid crystal layer has a multilayer structure of two or more layers, the liquid crystal can be sequentially coated The layer forming composition etc. 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. Regarding solvents, polymerization initiators, reactive additives, polymerization inhibitors, etc., it can be used in Japanese Patent Application Publication No. 2015-163937, Japanese Patent Application Publication No. 2016-42185, International Publication No. 2016/158940, and Japanese Patent Application Publication No. 2016- Those listed in Bulletin No. 224128.

The composition for forming the liquid crystal layer can be coated by spin coating, extrusion, gravure coating, die coating, slit coating, bar coating, spreading, etc. , Flexographic printing and other well-known methods. After coating 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 coating layer. The drying method includes, for example, a natural drying method, an air drying method, a heat drying method, and a reduced pressure drying method.

The polymerization of the polymerizable liquid crystal compound performed after the coating layer is dried 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. From the viewpoint of ease of polymerization, photopolymerization is preferred. When the polymerizable liquid crystal compound is polymerized by photopolymerization, it is preferable to use one containing a photopolymerization initiator as the composition for forming the liquid crystal layer. The composition for forming the liquid crystal layer is applied and dried to align the liquid crystal of the polymerizable liquid crystal compound contained in the dried film after drying, and photopolymerize while maintaining the liquid crystal alignment state.

Photopolymerization can be performed by irradiating active energy rays to the liquid crystal-aligned polymerizable liquid crystal compound in the dried film. The active energy rays to be irradiated can be appropriately selected depending on the type and amount of the polymerizable group contained in the polymerizable liquid crystal compound, the type of photopolymerization initiator, etc., for example, selected from visible light, ultraviolet light, laser light, and X-ray One or more active energy rays in the group consisting of, α rays, β rays and γ rays. Among them, from the viewpoint that it is easy to control the progress of the polymerization reaction and can be used as a photopolymerization device for a wide range of users in the field, ultraviolet light is preferred, and the polymerizability is preferably selected in a way that can be photopolymerized by ultraviolet light. Type 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 base material layer and the second base material layer (hereinafter, the two are also collectively referred to as the "base material layer"), have the first alignment layer and the second alignment layer to be described later formed on the base material layers, And the function of the support layer of the first liquid crystal layer and the second liquid crystal layer. The base material layer is preferably a film formed of a resin material.

As the resin material, for example, resin materials excellent in transparency, mechanical strength, thermal stability, stretchability, etc. can be used. Specifically, for example, polyolefin resins such as polyethylene and polypropylene; cyclic polyolefin resins such as norbornene 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; polyimine Series resins; polyether aldehyde resins; polyphenylene sulfide resins; polyphenylene ether resins, and mixtures and copolymers thereof. Among these resins, cyclic Any one of polyolefin resin, cellulose ester resin, and (meth)acrylic resin, or a mixture of these.

The base material layer may be a single resin or a single layer of a mixture of two or more, and may have a multilayer structure of two or more layers. When it has 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.

Any additives may be added to the resin material constituting the film formed of a resin material. Examples of additives include ultraviolet absorbers, antioxidants, lubricants, plasticizers, mold release agents, anti-coloring agents, flame retardants, nucleating agents, antistatic agents, pigments, and coloring agents.

The thickness of the first substrate layer and the second substrate layer is not particularly limited. From the viewpoint of general strength and workability, it is preferably 1 to 300 μm , more preferably 10 to 200 μm , And more preferably 30 to 120 μm .

When the first liquid crystal layer with a substrate layer has the first alignment layer described later, or when the second liquid crystal layer with a substrate layer has a 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 may be at least on the surface of the first substrate layer on the side where the first alignment layer is formed, and at least on the second substrate layer where the first alignment layer is formed. The surface on the side of the second alignment layer is subjected to corona treatment, plasma treatment, flame treatment, etc. to form a primer layer.

The substrate layer can be peeled from the liquid crystal layer or the alignment layer (first alignment layer or second alignment layer) described later. The peeling force between the substrate layer and the liquid crystal layer or the alignment layer must be taken into consideration. To determine the order. In addition to using the peeling force on a test piece for measurement with a liquid crystal layer on the base layer, or a test piece for measurement with an alignment layer and a liquid crystal layer on the base layer, it can also be used with the measurement between the peeling layer and the adhesive layer. The method of peeling force is measured in the same way. 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, still more preferably 0.05 to 0.18N/25mm. If the peeling force is lower than the above lower limit, floating may occur between the substrate layer and the liquid crystal layer or the alignment layer during transportation. In addition, if the peeling force exceeds the above upper limit, the adhesion is too high, and 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., which is useful for manufacturing optical laminates. During the steps, 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 second substrate layer and the second liquid crystal layer or and The difference in the peeling force between the second alignment layers described later (hereinafter also referred to as "second peeling force") is preferably 0.01 N/25mm or more, more preferably 0.03 N/25mm or more. When the first base material layer is peeled from the liquid crystal layered laminate with the base material layer first, it is preferable that the second peeling force is larger than the first peeling force.

(Orientation layer)

The first liquid crystal layer with a 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 a substrate layer may include a second alignment layer between the second substrate layer and the second liquid crystal layer.

The first alignment layer and the second alignment layer have an alignment control force to align the liquid crystal compounds contained in the first liquid crystal layer and the second liquid crystal layer formed on the alignment layers in a desired direction. The first alignment layer and the second alignment layer can be, for example, an alignment polymer layer formed of an alignment polymer, a photoalignment polymer layer formed of a photo-alignment polymer, and a layer having a concave-convex pattern or plural 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 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.

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

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

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

When the first liquid crystal layer with a substrate layer contains the first alignment layer, when the first substrate layer is peeled off, the first alignment layer can be peeled off at the same time as the first substrate 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 a substrate layer contains a second alignment layer, when the second substrate layer is peeled off, the second alignment layer can be peeled off simultaneously with the second substrate layer, or the second alignment layer can be left on the second liquid crystal layer Two alignment layer. In addition, the first alignment layer is to be peeled off at the same time as the first substrate layer, or left on the first liquid crystal layer, which can be set by adjusting the adhesion relationship between the layers, for example, by adjusting the first substrate The above-mentioned corona treatment, plasma treatment, flame treatment, primer layer treatment and other surface treatments of the material layer shape, or the composition of the liquid crystal layer forming composition used to form the first liquid crystal layer are adjusted. Similarly, by performing surface treatment on the second alignment layer, the second alignment layer can be peeled off at the same time as the first substrate layer, or can remain on 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. In addition, 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 Polarizing Plate)

The optical laminate of this embodiment can be used as a circularly polarizing plate. When the optical laminate 73 with an adhesive layer shown in Figure 6(b) is used as a circular polarizing plate, the optical film 60 can be used as a polarizer, a polarizing plate, or a polarizing plate 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 quarter wavelength retardation layer. Or, in the same manner as above, after using the optical film 60 as a polarizer, a polarizing plate, or a polarizing plate with a protective film, the first liquid crystal layer 12 is used as a reverse wavelength dispersion 1/4 wavelength retardation layer, and the second The liquid crystal layer 22 is used as a positive C plate, whereby a circular polarizing plate can also be obtained.

[Example]

Hereinafter, examples and comparative examples are disclosed and the present invention is explained more specifically, but the present invention is not limited to these examples. Unless otherwise specified, "%" and "parts" in the examples and comparative examples are mass% and mass parts.

[Preparation of adhesive layer with spacer film on both sides]

The adhesive is manufactured in the following way. Into a reaction vessel equipped with a stirrer, a thermometer, a reflux cooler, a dropping device, and a nitrogen introduction tube, 97.0 parts of n-butyl acrylate, 1.0 part of acrylic acid, 0.5 part of 2-hydroxyethyl acrylate, 200 parts of ethyl acetate, and 0.08 parts of 2,2'-azobisisobutyronitrile, and replace the gas in the above reaction vessel with nitrogen. While stirring in a nitrogen atmosphere, the reaction solution was heated to 60°C, 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.

The 100 parts of (meth)acrylate polymer obtained above (solid content conversion value; the same below) is used to modify toluene diisocyanate with trimethylolpropane, an isocyanate crosslinking agent (Dongsuo Co., Ltd. Co., Ltd., brand name "CoronateL") 0.30 parts, and 0.30 parts of 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Industrial Co., Ltd., brand name "KBM403") as a silane coupling agent, and mixed well. It is diluted with ethyl acetate to prepare a coating solution of the adhesive composition.

On the release treatment surface (release surface) of the first spacer film (manufactured by Lintec Co., Ltd.: SP-PLR382190) used as the release layer, the coating solution of the adhesive composition was applied with a spreader, and then heated at 100°C Dry for 1 minute to form an adhesive layer. On the opposite side of the diaphragm surface between the adhesive layer, attach another second spacer film (Lintec Co., Ltd.: SP-PLR381031) to obtain a double-sided spacer. The adhesive layer of the film.

[Preparation of Adhesive Composition]

After mixing the cationic curable components a1 to a3 and the cationic polymerization initiator shown below, the cationic polymerization initiator and sensitizer shown below are mixed and defoamed to prepare a light-curing form Adhesive composition. In addition, the following compounding amount is based on the solid content.

. Cationic hardening ingredient 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 content)):

Trade name: CPI-100 (made by San-Apro Co., Ltd.) 50% propylene carbonate solution

. 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 forming photo-alignment layer)

The following components were mixed, and the resulting mixture was stirred at a temperature of 80°C for 1 hour, thereby preparing a composition (1) for forming a photo-alignment layer.

. Optical alignment material (5 copies):

. Solvent (95 parts): cyclopentanone

(Preparation of composition (2) for formation of alignment layer)

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

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

The following components were mixed, and the resulting mixture was stirred at a temperature of 80°C for 1 hour, thereby preparing 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 2010-31223 A.

. Polymerizable 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 (Irgacure369: manufactured by Ciba Specialty Chemicals)

. 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, thereby preparing a liquid crystal layer forming composition (B-1).

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

. Polymerization initiator (0.5%):

Irgacure (registered trademark) 907 (made by BASF Japan)

. Reactive additives (1.1%):

Laromer (registered trademark) LR-9000 (made by BASF Japan)

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

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

A 100 μm thick polyethylene terephthalate (PET) film (first substrate layer) was used with a corona treatment device (AGF-B10, manufactured by Kasuga Electric Co., Ltd.) to output 0.3 kW and processing speed The condition of 3m/min is processed once. On the corona-treated surface, the photo-alignment layer forming composition (1) was coated with a bar coater, dried at 80°C for 1 minute, and polarized UV irradiation equipment (SPOT CURE SP-7; Ushio Electric Co., Ltd. Made by the company), the light alignment layer is obtained by performing polarized UV exposure with a cumulative light amount of 100mJ/cm ² . The thickness of the obtained photo-alignment layer measured with a laser microscope (LEXT, manufactured by Olympus Co., Ltd.) was 100 nm.

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

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

Except that the ultraviolet irradiation intensity of the high-pressure mercury lamp is 50mW/cm ² , the first liquid crystal layer with the substrate layer (i) was produced in the same order as the first liquid crystal layer with the substrate layer ( ii) (Figure 1(a)). The thickness of the first liquid crystal layer is 2 μm .

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

Except that the UV irradiation intensity of the high-pressure mercury lamp is 400mW/cm ² , the first liquid crystal layer with the substrate layer (i) was produced in the same order as the first liquid crystal layer with the substrate layer ( iii) (Figure 1(a)). The thickness of the first liquid crystal layer is 2 μm .

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

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

Next, the liquid crystal layer forming composition (B-1) was coated on the alignment layer using a bar coater, dried at 90°C for 1 minute, and then a high-pressure mercury lamp (UnicureVB-15201BY-A, manufactured by Ushio Electric Co., Ltd.) , Detect ultraviolet rays (under nitrogen atmosphere, wavelength: 365nm, cumulative light quantity of wavelength 365nm: 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 film]

A cyclic polyolefin film with a protective film (thickness 23 μm , ZF-14, manufactured by Zeon Co., Ltd.) (hereinafter, also referred to as "COP with protective film) with a length of 380 mm in the MD direction and 180 mm in the TD direction ") The cyclic polyolefin film surface on the opposite side of the protective film side is corona treated (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 the spacer film on both sides prepared above, were pasted using the automatic laminating device HALTEC (Sankyo Co., Ltd.) Together, an optical film with spacer film is prepared.

[Measurement of TD curl of optical laminate]

Place the optical laminates with substrate layer obtained in each example and each comparative example in an environment with a temperature of 23°C and a relative humidity of 55% for 24 hours, and then cut a rectangle with a long side length of 150mm and a short side length of 50mm. Cut the section, peel off the protective film, and make a test piece with 38 μm thick polyethylene terephthalate (second substrate layer). Cut the slices so that the long side and 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) are at an angle of 45 degrees Way of cutting.

After the test piece is sufficiently removed from static electricity, it is placed on the reference surface (horizontal platform) with the concave surface of the test piece facing up, and the diagonals of the test piece are opposite to the direction parallel to the TD direction. The two corners on the closer diagonal are measured from the reference plane. The measured value, if the test piece is placed on the reference surface with the side of the cyclic polyolefin film (hereinafter also referred to as "COP film") exposed by the peeling protective film being the upper side, when the 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 surface is expressed as a positive value. On the other hand, if the test piece is placed on the reference surface so that the COP film side is the lower side, when the above two corners of the test piece are floating, the curl is regarded as a rewind, and it is raised from the reference surface. The height of the corner is expressed as a negative value. The average of the values measured for the above two angles is regarded as the TD curl value of the optical laminate.

In addition, since the TD curl value of the optical film with the protective film and the adhesive layer of the spacer film peeled from the optical film with the release film is 0 when measured in the same procedure as above, the TD curl value of the optical laminate is It can be presumed to be the same as the TD curl value of the laminate having the layer structure of the first liquid crystal layer/first adhesive layer/second 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 spacer film was used as an auxiliary film for measurement with spacer film. Place the auxiliary film for measurement with spacer film in an environment with a temperature of 23°C and a relative humidity of 55% for 24 hours, then cut a rectangular section with a long side length of 150 mm and a short side length of 50 mm, and peel off the protective film and the Two spacer films are used as test pieces for auxiliary films for measurement. This cut piece is cut in the same manner 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 the test piece of the auxiliary film for measurement is sufficiently removed from static electricity, in the same procedure as described above, in the diagonal line of the test piece, the direction of extension and the TD direction (with the first liquid crystal layer and the second liquid crystal layer described later) are measured. When measuring the TD curl of the two liquid crystal layers, the TD direction is the same). The parallel direction is the height from the two corners on the diagonal that is relatively close, and the average value is used 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 spacer film was used as an auxiliary film for measurement with spacer film. The adhesive layer exposed by peeling off the second spacer film from the measuring auxiliary film with spacer film and the first liquid crystal layer of the first liquid crystal layer with the substrate layer obtained above are bonded together using an automatic bonding device HALTEC, The first liquid crystal layer with the auxiliary film for measurement was prepared. After placing the first liquid crystal layer of the auxiliary film for measurement in an environment with a temperature of 23°C and a relative humidity of 55% for 24 hours, a rectangular section with a long side length of 150 mm and a short side length of 50 mm was cut to protect it from peeling. The film and the polyethylene terephthalate film (first substrate layer) were used to obtain a laminate (a) as a test piece (layer structure: cyclic polyolefin film/adhesive layer/first liquid crystal layer). The cut piece is cut so that its long side and the TD direction of the first liquid crystal layer with the base material layer are at an angle of 45 degrees.

After the resulting layered body (a) is sufficiently removed from static electricity, in the same procedure as described above, in the diagonal line of the layered body (a), the diagonal line of the layered body (a) is measured from the pair which is relatively close to the direction parallel to the TD direction. The height from the reference plane of the two corners on the corner line is taken as the average value of 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 and used as the curl value of the first liquid crystal layer. Table 1 shows the curl value of the first liquid crystal layer of each first liquid crystal layer with a substrate layer. The "cylindrical shape" in Table 1 refers to the state in which the laminate (a) is curled into a cylindrical shape, so it is estimated that the curl value of the first liquid crystal layer exceeds 20 mm.

In addition, except that the second liquid crystal layer with a substrate layer was used instead of the first liquid crystal layer with a substrate layer, a laminate (b) was produced in the same manner as above (layer structure, COP film/adhesive layer/second Liquid crystal layer). The curl value of the second liquid crystal layer was calculated in the same manner as described above except that the layered product (b) was used instead of the above-mentioned layered product (a). Table 1 shows the curl value of the second liquid crystal layer of the second liquid crystal layer with a substrate layer.

[Determination of storage elastic modulus E]

The storage elastic modulus E [Pa] at a temperature of 30°C when the active energy ray-curable adhesive is used as the first adhesive layer is calculated as follows. On one side of a cyclic polyolefin resin film with a thickness of 50 μm , use a coater [bar coater, manufactured by Daiichi Rika Co., Ltd.] to apply an active energy ray curable adhesive, and then apply the coating surface A cyclic polyolefin resin film with a thickness of 50 μm is laminated. Next, the "D lamp" manufactured by FUSION UV SYSTEMS was irradiated with ultraviolet light so that the accumulated light amount was 1500 mJ/cm ² (UVB) to harden the adhesive composition layer. Cut it into a size of 5mm×30mm, and peel off one of the cyclic olefin resin films to obtain an adhesive hardened layer with a resin film. The resin film-attached adhesive hardened layer was held so that its long side was in the stretching direction using a dynamic viscoelasticity measuring device "DVA-220" made by IT Measurement Control (Strand) with a clamp interval of 2 cm. The frequency of stretching and contraction is set to 10 Hz, the heating rate is set to 10°C/min, and the temperature is raised to obtain the storage elastic modulus E at a temperature of 30°C.

[Measurement of thickness t]

The thickness t of the first bonding layer (the bonding layer for bonding the first liquid crystal layer and the second liquid crystal layer) was measured as follows using a contact thickness meter (Digimicrohead MH-15M, manufactured by Nikon Co., Ltd.). First, using the contact-type film thickness meter described above, the film thicknesses of the first liquid crystal layer with a base material layer and the second liquid crystal layer with a base material layer are measured. Next, the double-sided substrate layer-attached liquid crystal laminate obtained by bonding the first liquid crystal layer with a substrate layer and the second liquid crystal layer with a substrate layer after measuring the film thickness were measured with the substrate layer The film thickness of the first liquid crystal layer and the second liquid crystal layer with the substrate layer are measured at the same position. From the measured film thickness of the liquid crystal laminate with base layer on both sides and the total film thickness of the first liquid crystal layer with base layer and the second liquid crystal layer with base layer, the first adhesive is calculated The thickness of the layer t.

[Example 1]

The surface of the second liquid crystal layer side of the second liquid crystal layer (MD direction length 380mm×TD length direction 180mm) prepared above was subjected to corona treatment (800W, 10m/min, rod width 700mm, 1Pass). The adhesive composition prepared above was used to form the adhesive composition layer using a coater (bar coater manufactured by the First Physical Chemical Co., Ltd.), and a second liquid crystal layer with a composition layer (No. 1 Figure (c)). Next, corona treatment is applied to the surface of the first liquid crystal layer side of the first liquid crystal layer (i) (MD direction length 380mm×TD length direction 180mm) prepared above with the substrate layer, under the same conditions, After the corona treatment surface and the adhesive composition layer of the second liquid crystal layer with the composition layer are pasted using a pasting device ("LPA3301" manufactured by FUJIPLA (stock)) (Figure 1 (d)), On the side of the second liquid crystal layer of the second liquid crystal layer with the base layer, the ultraviolet irradiation device with the attached conveyor (the lamp uses the "H lamp" manufactured by FUSION UV SYSTEMS), so that the irradiation intensity of the UVA area is 390mW/cm ² , the cumulative light quantity is 420mJ/cm ² , the UVB area irradiation intensity is 400mW/cm ² , the cumulative light quantity is 400mJ/cm ² , irradiating ultraviolet rays to harden the adhesive composition, and have two sides The liquid crystal laminate of the base layer (refer to Figure 2(a)). As a result of measuring the storage elastic modulus E and thickness t of the first adhesive layer of the adhesive hardened layer after the 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 100 μm- thick polyethylene terephthalate film (first base layer) was peeled off from the liquid crystal laminated body with base layer on both sides to obtain the liquid crystal laminated body with base layer on one side (Figure 2 (b)). The exposed surface (photo-alignment layer) of the liquid crystal laminate with a single-sided substrate layer exposed by the peeling off, and the optical film with the isolation film prepared above, peel off the adhesive exposed by the second spacer film The layers were bonded using an automatic bonding device HALTEC (Sankyo Co., Ltd.) to prepare an optical laminate with a substrate layer (Figure 4(a)). Using the optical laminate with a substrate layer, the TD curl was measured by the above-mentioned procedure, and the TD curl value of the optical laminate was calculated. The results are shown in Table 1.

[Example 2]

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

[Example 3]

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

[Example 4]

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

[Example 5]

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

[Comparative Example 1]

Except that the first liquid crystal layer with a substrate layer (iii) prepared above was used instead of the first liquid crystal layer (i) with a substrate layer, the same procedure as in Example 3 was used to prepare a liquid crystal with a substrate layer A laminated body and an optical laminated body with a substrate layer. The storage elastic modulus E of the first adhesive layer is 3000 MPa. In addition, using the obtained optical laminate with a substrate layer, the TD curl was measured by the above-mentioned steps, and the TD curl value of the optical laminate 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 rewinding, and the optical laminates obtained in Examples 1 to 4 are in a more planar (flat) state. On the other hand, in Comparative Example 1, it can be seen that the rewind of the optical laminate increases.

Claims (18)

A method for manufacturing a liquid crystal layered body, the liquid crystal layered system has at least a first liquid crystal layer, a first adhesive layer, and a second liquid crystal layer laminated in sequence. The method of manufacturing includes the following steps: The step of preparing a first liquid crystal layer with a substrate layer, the first liquid crystal layer with a substrate layer having a first substrate layer, and the aforementioned first substrate layer formed by polymerizing a polymerizable liquid crystal compound on the aforementioned first substrate layer A liquid crystal layer; The step of preparing a second liquid crystal layer with a substrate layer, the second liquid crystal layer with a substrate layer having a second substrate layer, and the aforementioned second substrate layer formed by polymerizing a polymerizable liquid crystal compound on the aforementioned second substrate layer Two liquid crystal layers; and The step of laminating is by interposing the first adhesive layer on the first liquid crystal layer side of the first liquid crystal layer with the base material layer, and laminating the second liquid crystal layer side of the second liquid crystal layer with the base material layer, among them, The aforementioned first adhesive layer is an adhesive hardened layer composed of a hardened material of a curable adhesive, The absolute value of the curl amount of the aforementioned first liquid crystal layer is within 20mm, The absolute value of the curl amount of the aforementioned second liquid crystal layer is within 20 mm. The method for manufacturing a liquid crystal laminate as described in the first item of the patent application, wherein when the storage elastic modulus of the first adhesive layer at a temperature of 30°C is set to E[Pa], and the thickness is set to 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 laminate as described in item 1 or 2 of the scope of the patent application further includes a step of peeling off the first substrate layer after the lamination step. A liquid crystal layered body at least has a first liquid crystal layer, a first adhesive layer, and a second liquid crystal layer laminated in sequence, 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 cured layer composed of a cured product of a curable adhesive, The absolute value of the curl amount of the aforementioned first liquid crystal layer is within 20mm, The absolute value of the curl amount of the aforementioned second liquid crystal layer is within 20 mm. The liquid crystal laminate as described in item 4 of the scope of 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 aforementioned first adhesive layer satisfies the relationship of the following formula (1), 3000≦E×t≦15000 (1). The liquid crystal laminate according to claim 4 or 5, wherein the second liquid crystal layer has a second base layer on the side opposite to the first adhesive layer. The liquid crystal laminated body described in the scope of patent application 6 further has a first base material layer on the side opposite to the first adhesive layer of the first liquid crystal layer. A method for manufacturing an optical laminate, the optical laminate system at least sequentially laminates 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: In the liquid crystal laminated body manufactured by the method of manufacturing the liquid crystal laminated body described in the third clause of the patent application, the first exposed surface side exposed by the first base material layer is peeled off. The liquid crystal laminate described in item 7 peels off the side of the first exposed surface exposed by the first base material layer, or the liquid crystal laminate described in item 6 of the scope of patent application on the side of the first liquid crystal layer, and layers are sequentially laminated The second adhesive layer and optical film step. The method for manufacturing an optical laminate as described in claim 8 includes the step of sequentially laminating the second adhesive layer and the optical film, and further includes the step of peeling off the second substrate layer. The manufacturing method of the optical laminate described in item 9 of the scope of patent application further includes the following steps: The step of preparing an adhesive layer with an adhesive layer and a release layer attached to the release layer; and A step of laminating the adhesive layer side of the adhesive layer with the peeling layer on the second exposed surface side exposed by peeling the second base material layer. The method for manufacturing an optical laminate as described in claim 10 includes the step of peeling off the peeling layer after the step of laminating the adhesive layer with the peeling layer on the side of the adhesive layer. The method for manufacturing an optical laminate according to any one of claims 8 to 11, wherein the optical film contains a polarizing plate. An optical laminate having at least an optical film, a second adhesive layer, a first liquid crystal layer, a first adhesive layer, and a second liquid crystal layer laminated in this order, 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 cured layer composed of a cured product of a curable adhesive, The absolute value of the curl amount of the aforementioned first liquid crystal layer is within 20mm, The absolute value of the curl amount of the aforementioned second liquid crystal layer is within 20 mm. The optical laminate described in item 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 set to E [Pa] and the thickness is set to t [m], the aforementioned The first adhesive layer satisfies the relationship of the following formula (1), 3000≦E×t≦15000 (1). The optical laminate described in claim 13 or 14, wherein the second liquid crystal layer has a second substrate layer on the side opposite to the first adhesive layer. The optical laminate described in claim 13 or 14, wherein the second liquid crystal layer has an adhesive layer on the side opposite to the first adhesive layer. The optical layered body described in the 16th patent application, wherein the adhesive layer has a release layer on the side opposite to the second liquid crystal layer. The optical laminate according to any one of the claims 13 to 17, wherein the optical film contains a polarizing plate.

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