TW201505850A - Production method of polarizing plate - Google Patents

Abstract

A manufacturing method of a polarizing plate is provided. The polarizing plate has an optical anisotropy layer formed by a composition including a liquid crystal compound. The method includes: preparing a transfer material including a temporary support and the optical anisotropy layer, wherein the optical anisotropy layer is a layer formed by a polymerizable composition which contains liquid crystal compounds by directly coating on the temporary support or directly coating on the other layer disposed on the temporary support; peeling the temporary support from a laminate of the laminate film and the transfer material; and adhering a film containing a polarizer on a face that is obtained by the peeling the laminate; and peeling the laminate film. The optical anisotropy layer can be adhered on the polarizer with minimized construction by the manufacturing method.

Description

Polarizing plate manufacturing method

The present invention relates to a method of manufacturing a polarizing plate. More particularly, the present invention relates to a method of producing a polarizing plate having an optically anisotropic layer formed of a composition containing a liquid crystal compound.

Due to the expansion of markets such as smartphones or tablet PCs (Personal Computers), displays are increasingly becoming thinner. Among the above-described flows, thickness reduction is also required in the retardation film for compensating for the viewing angle of the liquid crystal display device. A large number of examples in which a film having a specific phase difference is used as a protective film of a polarizing plate and the phase difference is achieved by alignment of a liquid crystal compound (for example, Patent Document 1 and Patent Document 2) are known, but by including a liquid crystal compound. Since the optically anisotropic layer formed by photohardening of the composition is low in self-supporting property, it is usually formed on a transparent support such as a deuterated cellulose-based polymer film, and is directly used, and the optically anisotropic layer is thinned. It needs to be studied in a form containing a support. On the other hand, Patent Document 3 discloses that a composition containing a liquid crystal compound is directly applied onto the surface of the polarizing film to form an optically anisotropic layer, and a thin polarizing plate is realized.

[Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2013-050572

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2011-133549

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2004-53770

An object of the present invention is to provide a polarizing plate having a small film thickness. In particular, an object of the present invention is to provide a method for producing a polarizing plate having an optically anisotropic layer formed of a composition containing a liquid crystal compound, and the manufacturing method can make the optical body with a minimum configuration The anisotropic layer is bonded to the polarizing element.

In order to solve the above problems, the inventors of the present invention have conducted intensive studies, and as a result, found that optical anisotropy on a temporary support formed by photohardening of a composition containing a liquid crystal compound which cannot be peeled off without defects The layer can be peeled off from the temporary support as a laminate with the alignment layer without defects, and the adhesion between the side faces of the alignment layer and the polarizing element is good, and the present invention has been completed based on the above findings. That is, the present invention provides the following [1] to [12].

[1] A method of producing a polarizing plate, comprising the following (1) to (3): (1) preparing a transfer material, the transfer material sequentially comprising a temporary support, an alignment layer, and an anisotropic layer. And the optically anisotropic layer is a layer formed of a polymerizable composition containing a liquid crystal compound directly coated on the alignment layer; (2) the temporary support body of the transfer material and the alignment Stripping the temporary support between the layers; and (3) The surface obtained by the peeling of the transfer body including the optically anisotropic layer and the alignment layer obtained by the peeling is adhered to a film including a polarizing element.

[2] The production method according to [1], wherein an outermost layer of the transfer body is the alignment layer, and the alignment layer is directly bonded to the film including a polarizing element.

[3] The manufacturing method according to [1] or [2], wherein the polarizing element in the film including the polarizing element is directly bonded to the alignment layer.

[4] The production method according to any one of [1] to [3] wherein the alignment layer contains modified or unmodified polyvinyl alcohol.

[5] The production method according to any one of [1] to [4] wherein the polarizing element comprises modified or unmodified polyvinyl alcohol.

[6] The production method according to any one of [1] to [5] wherein the adhesion of the transfer body to the film including the polarizing element is performed using modified or unmodified polyethylene It is carried out with an alcohol binder.

[7] The manufacturing method according to any one of [1] to [6] wherein, between the (1) and the (2), the transfer material is cut to be less than 0.025 m ² The steps of the area.

[8] The production method according to any one of [1] to [7] wherein the temporary support comprises a polyester.

[9] The production method according to [8], wherein the temporary support comprises polyethylene terephthalate.

[10] The manufacturing method according to any one of [1] to [9] further comprising The transfer material is produced by the following manufacturing method, the method comprising: directly coating the polymerizable composition containing a liquid crystal compound on a surface of the alignment layer; and applying the obtained coating layer to light irradiation or heating.

[11] The production method according to any one of [1] to [10] wherein the optically anisotropic layer has a film thickness of 0.5 μm to 5 μm.

[12] The production method according to any one of [1] to [10] wherein the optically anisotropic layer has a film thickness of 0.5 μm to 3 μm.

According to the present invention, a method of producing a polarizing plate of a film can be provided. According to the production method of the present invention, regardless of the type of the liquid crystal compound, the optically anisotropic layer formed of the composition containing the liquid crystal compound can be bonded to a plurality of types of polarizing elements with a minimum configuration to produce a polarizing plate.

1‧‧‧Polarized elements

2‧‧‧ Optical anisotropic layer

4‧‧‧Protective film 1

5‧‧‧hard coating

6‧‧‧Protective film 2

12‧‧‧Alignment layer

FIG. 1 is a view showing an example of a layer configuration of a polarizing plate manufactured by the production method of the present invention.

Hereinafter, the present invention will be described in detail.

In addition, in the present specification, "~" is used in the sense that the numerical values described before and after are included as the lower limit and the upper limit. In the present specification, the "polarizing plate" is a size that includes a long polarizing plate and is cut into a liquid crystal display device unless otherwise specified (in the present specification, "cutting" also includes "punching" and " cut It is used for the meaning of both of the polarizing plates. In the present specification, the "polarizing element" (also referred to as "polarizing film") and the "polarizing plate" are used separately, but the "polarizing plate" means having at least one side of the "polarizing element". a laminate of membranes.

In addition, in the present specification, the description of "(meth) acrylate" means "any or both of acrylate and methacrylate". "(Meth)acrylic acid" and the like are also the same.

In the present specification, Re(λ) and Rth(λ) respectively indicate the in-plane retardation at the wavelength λ and the retardation in the thickness direction. Re(λ) is measured by injecting light having a wavelength of λ nm into the normal direction of the film in KOBRA 21ADH or WR (manufactured by Oji Scientific Instruments Co., Ltd.). When the measurement wavelength λ nm is selected, it can be measured by manually converting the wavelength selection filter or by converting the measurement value by a program or the like.

When the measured film is represented by a uniaxial or biaxial refractive index ellipsoid, Rth(λ) is calculated by the following method.

With respect to the slow axis in the plane (determined by KOBRA 21ADH or WR), the film normal direction of the tilt axis (rotation axis) (any direction in the film surface is used as the rotation axis when there is no slow axis) From the normal direction to 50 degrees on one side, the light of the wavelength λ nm is incident from the direction of the inclination in units of 10 degrees, and all the points of Re (λ) are measured, and the average value and the average value are determined based on the measured delay value and average. The assumed value of the refractive index and the input film thickness value are calculated from KOBRA 21ADH or WR by Rth(λ).

In the above, when the slow axis in the plane is used as the rotation axis and the film having a retardation value of 0 at a certain inclination angle with respect to the normal direction is larger than the inclination The delay value at a large angle of inclination is calculated by KOBRA 21ADH or WR after the sign is changed to negative.

In addition, the slow axis may be used as the tilt axis (rotation axis) (any direction in the film surface may be used as the rotation axis when there is no slow axis), and the delay value may be measured from two directions of arbitrary inclination, according to the value and the average refractive index. The assumed value and the input film thickness value are calculated by the following formulas (11) and (12).

The Re(θ) represents a retardation value when the direction of the normal direction is inclined by the angle θ.

In the formula (11), nx represents a refractive index in the slow axis direction in the plane, ny represents a refractive index in a direction orthogonal to nx in the plane, and nz represents a refractive index in a direction orthogonal to nx and ny. d is the film thickness.

Equation (12): Rth={(nx+ny)/2-nz}×d

In the formula (12), nx represents a refractive index in the slow axis direction in the plane, ny represents a refractive index in a direction orthogonal to nx in the plane, and nz represents a refractive index in a direction orthogonal to nx and ny. d is the film thickness.

When the film to be measured is a film which cannot be represented by a uniaxial or biaxial refractive index ellipsoid, that is, a so-called optic axis, Rth(λ) is calculated by the following method.

The in-plane slow axis (determined by KOBRA 21ADH or WR) is used as the tilting axis (rotating axis), and the film normal is applied from the direction of inclination to the film in the range of 10 degrees from -50 degrees to +50 degrees. The light having a wavelength of λ nm is incident on the light, and Re (λ) at 11 points is measured, and Rth (λ) is calculated from KOBRA 21ADH or WR based on the measured retardation value and the assumed value of the average refractive index and the input film thickness value.

In the measurement, the assumed value of the average refractive index can be used as a catalogue value of various optical films in "Polymer Handbook" (JOHN WILEY & SONS, INC). The value of the average refractive index is unknown, and can be measured by an Abbe refractometer. The values of the average refractive index of the main optical film are exemplified below: deuterated cellulose (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), polystyrene ( 1.59). By inputting the assumed value of the average refractive index and the film thickness, KOBRA 21ADH or WR calculates nx, ny, and nz. Based on the calculated nx, ny, and nz, Nz = (nx - nz) / (nx - ny) is further calculated.

In the present specification, when there is no special note on the measurement wavelength, the measurement wavelength is 550 nm. For example, when it is abbreviated as Re, it means Re (550). In the present specification, the optical isotropy means that the absolute value of the in-plane retardation (Re (550)) is 10 nm or less, and the absolute value of the thickness direction retardation (Rth) is 10 nm or less. The so-called delay is not substantially zero, which means that Re is greater than 10 nm.

In addition, in this specification, regarding an angle (for example, an angle such as "90°"), and The relationship (for example, "orthogonal", "parallel", and "crossing at 45", etc.) is set to include a range of errors allowed in the technical field to which the present invention pertains. For example, it means that the error is less than a strict angle of ±10°, and the error with a strict angle is preferably 5° or less, more preferably 3° or less. Further, the retardation is substantially 0, and means Re (550) ≦ 10 nm and Rth (550) ≦ 10 nm, preferably Re (550) ≦ 5 nm or less and Rth (550) ≦ 5 nm.

[Polarizer]

The polarizing plate manufactured by the manufacturing method of the present invention comprises an optically anisotropic layer and a polarizing element. It suffices to arrange an optically anisotropic layer on either or both sides of the polarizing element. The polarizing plate preferably further includes an alignment layer for aligning the liquid crystal compound when the optically anisotropic layer is formed. The polarizing plate may further include other layers such as a protective film for protecting the surface of the polarizing element or the optically anisotropic layer.

An example of a layer configuration of a polarizing plate manufactured by the production method of the present invention is shown in Fig. 1 . In addition, in the figure, the adhesive layer is omitted.

The film thickness of the polarizing plate is not particularly limited, and may be about 50 μm to 500 μm. In particular, the polarizing plate can be formed of a film of 200 μm or less, 150 μm or less, 120 μm or less, 100 μm or less, 90 μm or less, 80 μm or less, or 70 μm or less by the production method of the present invention.

[Transfer material]

In the production method of the present invention, a transfer material comprising a temporary support, an alignment layer, and an optically anisotropic layer in this order is used. In the manufacturing method of the present invention, the step of transferring the optically anisotropic layer from the transfer material to the film containing the polarizing element The optically anisotropic layer formed by coating can be formed without depending on the kind or property of the film containing the polarizing element, and an optically anisotropic layer of an alignment form of various liquid crystal compounds using various liquid crystal compounds can be formed. For example, the heating step required to form the optically anisotropic layer may affect the properties of the polarizing element, but by using a manufacturing method of the transfer material, optical parts can be produced without affecting the polarizing element. To the opposite layer.

The transfer material is a material that can peel off the temporary support to provide an optically anisotropic layer. In the present specification, the object to be transferred to the film including the polarizing element, that is, the object to be bonded to the film including the polarizing element may be referred to as a "transfer body". In the present invention, the transfer body is a film including an optically anisotropic layer and an alignment layer obtained by peeling off the temporary support from the transfer material.

In the transfer material, the alignment layer and the optically anisotropic layer are preferably in contact with each other. The temporary support and the alignment layer may be in contact with each other, and another layer such as a release layer or a release layer may be present between the temporary support and the alignment layer.

The transfer material can be produced by directly coating a polymerizable composition containing a liquid crystal compound on the surface of the alignment layer of the temporary support having the alignment layer, and subjecting the obtained coating layer to light irradiation to polymerize the liquid crystal containing compound. The composition is hardened to form an optically anisotropic layer.

Hereinafter, each layer included in the polarizing plate or the transfer material will be described in detail.

[Optical anisotropic layer]

The optically anisotropic layer is a layer having an incident direction in which the retardation is substantially not zero when the retardation is measured, and is a layer having non-isotropic optical characteristics. In the present invention The optically anisotropic layer which can be used is a layer formed of a polymerizable composition containing a liquid crystal compound. For example, the optically anisotropic layer may be formed by polymerizing a liquid crystalline compound by applying a polymerizable composition containing a liquid crystal compound to light irradiation or heating. The polymerizable composition may be a liquid crystal compound containing at least one polymerizable group, and the liquid crystal compound may be polymerized by a polymerizable group by light irradiation or heating. The polymerizable composition is preferably applied directly to an alignment layer provided on the temporary support. The coating layer is further dried by heating at room temperature or the like (for example, heating at 50 ° C to 150 ° C, preferably 80 ° C to 120 ° C), whereby the liquid crystal compound molecules in the layer can be aligned. The optically anisotropic layer may be formed by polymerizing and immobilizing the coating layer.

The film thickness of the optically anisotropic layer may be 10 μm or less, less than 8 μm, 7 μm or less, 6 μm or less, 5 μm or less, 4 μm or less, 3 μm or less, 2 μm or less, 1.9 μm or less, 1.8 μm or less, 1.7 μm or less, and 1.6 μm or less. 1.5 μm or less, 1.4 μm or less, 1.3 μm or less, 1.2 μm or less, 1.1 μm or less, or 1 μm or less, and may be 0.2 μm or more, 0.3 μm or more, 0.4 μm or more, 0.5 μm or more, 0.6 μm or more, and 0.7 μm or more. 0.8 μm or more and 0.9 μm or more. The optically anisotropic layer is also preferably transparent (for example, a light transmittance of 80% or more).

[2-layer optical anisotropic layer]

The polarizing plate may include two or more optically anisotropic layers. Two or more optically anisotropic layers may be in direct contact with each other in the normal direction, or another layer such as an alignment layer may be sandwiched therebetween. The polymerizable composition forming two or more layers may be the same as or different from each other. For example, in a combination of two layers of optically anisotropic layers, it may be comprised of rods The combination of the layers formed by the composition of the liquid crystal compound or the combination of the layers formed of the composition containing the discotic liquid crystal compound may also be a layer formed of a composition containing a rod-like liquid crystal compound and a disc containing the disc. A combination of layers formed by the composition of the liquid crystal compound. When the polarizing plate contains two or more optically anisotropic layers, the optically anisotropic layer produced previously can function as an alignment layer of the optically anisotropic layer to be formed later. At this time, the optically anisotropic layer previously produced can be rubbed. When two or more optically anisotropic layers are included, it is preferred that the total thickness of the optically anisotropic layer is the film thickness.

The two-layer optically anisotropic layer, for example, may have a function as a λ/4 phase difference plate. The λ/4 phase difference plate is combined with a polarizing element (linear polarizing element) to function as a circularly polarizing plate.

The phase difference plate has many applications and has been used in a liquid crystal display (LCD), a semi-transmissive LCD, a brightness enhancement film, an organic electroluminescence (EL) display device, and a touch panel (touch). Panel) and so on. For example, an organic EL (organic electroluminescence) device has a structure in which a layer having a different refractive index is laminated, or a structure in which a metal electrode is used. Therefore, external light is reflected at an interface of each layer to cause a problem of contrast reduction or reflection glare. Happening. Therefore, in order to suppress the adverse effect due to external light reflection, a circularly polarizing plate composed of a retardation film and a polarizing film has been used in an organic EL display device, an LCD display device, or the like.

[Liquid Crystal Compound]

Examples of the liquid crystal compound include a rod-like liquid crystal compound and a discotic liquid crystal. Compound.

As the rod-like liquid crystal compound, a methylimine, an oxyazo, a cyanobiphenyl, a cyanophenyl ester, a benzoate, a phenyl cyclohexanecarboxylate or a cyano group can be preferably used. Phenylcyclohexanes, cyano-substituted phenylpyrimidines, alkoxy-substituted phenylpyrimidines, phenyldioxanes, diphenylacetylenes, and alkenylcyclohexylbenzonitriles. Not only low molecular liquid crystal molecules as described above but also polymer liquid crystal molecules can be used.

More preferably, the alignment of the rod-like liquid crystal compound is fixed by polymerization, and as the polymerizable rod-like liquid crystal compound, it is possible to use: Polymer Chemistry (Makromol. Chem.), Vol. 190, p. 2255 (1989), "Advanced Advanced Materials, Vol. 5, p. 107 (1993), U.S. Patent No. 4,683,327, U.S. Patent No. 5,622,648, U.S. Patent No. 5,770,107, WO 95/22586, WO 95/24455, WO 97/00600, WO 98/ Japanese Patent Laid-Open No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. Hei. No. Hei. Hei. Hei. Hei. Hei. A compound described in JP-A-2013-050583, and the like. In addition, as the polymerizable rod-like liquid crystal compound, a polymerizable rod-like liquid crystal compound represented by the following formula (1) is preferable.

General formula (1) Q ¹ -L ¹ -Cy ¹ -L ² -(Cy ² -L ³ )n-Cy ³ -L ⁴ -Q ²

(In the formula (1), Q ¹ and Q ² are each independently a polymerizable group, and L ¹ and L ⁴ are each independently a divalent linking group, and L ² and L ³ are each independently a single bond or a divalent linkage. The bases, Cy ¹ , Cy ² and Cy ³ are divalent cyclic groups, and n is 0, 1, 2 or 3.)

The polymerizable rod-like liquid crystal compound represented by the formula (1) will be further described below.

In the formula (1), Q ¹ and Q ² are each independently a polymerizable group. The polymerization of the polymerizable group is preferably an addition polymerization (including ring-opening polymerization) or a condensation polymerization. In other words, the polymerizable group is preferably a functional group capable of undergoing an addition polymerization reaction or a condensation polymerization reaction. An example of a polymerizable group is shown below.

Among the above, preferred examples of the polymerizable group include an acrylic group and a methacryl group. Particularly preferably, both of Q ¹ and Q ² in the formula (1) are an acrylic group or a methacryl group.

In the formula (1), L ¹ and L ⁴ are each independently a divalent linking group. L ¹ and L ⁴ are each independently preferably selected from the group consisting of -O-, -S-, -CO-, -NR-, -C=N-, a divalent chain group, a divalent cyclic group, and the like. Combine the divalent linkages of the group consisting of. The R is an alkyl group having 1 to 7 carbon atoms or a hydrogen atom. R is preferably an alkyl group having 1 to 4 carbon atoms or a hydrogen atom, more preferably a methyl group, an ethyl group or a hydrogen atom, and most preferably a hydrogen atom.

An example including a combined divalent linking group is shown below. Here, the left side is bonded to Q (Q ¹ or Q ² ), and the right side is bonded to Cy (Cy ¹ or Cy ³ ).

L-1:-CO-O-divalent chain-based-O-

L-2:-CO-O-divalent chain-based-O-CO-

L-3: -CO-O-divalent chain-based O-CO-O-

L-4: -CO-O-divalent chain group -O-divalent cyclic group -

L-5:-CO-O-divalent chain-O-divalent cyclic group-CO-O-

L-6:-CO-O-divalent chain-O-divalent cyclic group-O-CO-

L-7: -CO-O-divalent chain-O-divalent cyclic group-divalent chain group-

L-8:-CO-O-divalent chain-O-divalent cyclic group-divalent chain group-CO-O-

L-9:-CO-O-divalent chain-O-divalent cyclic group-divalent chain group-O-CO-

L-10:-CO-O-divalent chain-O-CO-divalent cyclic group-

L-11:-CO-O-divalent chain-O-CO-divalent cyclic group-CO-O-

L-12:-CO-O-divalent chain-O-CO-divalent cyclic group-O-CO-

L-13:-CO-O-divalent chain-O-CO-divalent cyclic group-divalent chain group-

L-14:-CO-O-divalent chain-O-CO-divalent cyclic group-divalent chain group-CO-O-

L-15:-CO-O-divalent chain-O-CO-divalent cyclic group-divalent chain group -O-CO-

L-16:-CO-O-divalent chain-O-CO-O-divalent cyclic group-

L-17:-CO-O-divalent chain-O-CO-O-divalent cyclic group-CO-O-

L-18:-CO-O-divalent chain-O-CO-O-divalent cyclic group-O-CO-

L-19:-CO-O-divalent chain-O-CO-O-divalent cyclic group-divalent chain group-

L-20:-CO-O-divalent chain-O-CO-O-divalent cyclic group-divalent chain group-CO-O-

L-21:-CO-O-divalent chain-O-CO-O-divalent cyclic group-divalent chain group-O-CO-

The divalent chain group means an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an alkynyl group, or a substituted alkynyl group. Preferred are an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, more preferably an alkyl group and an alkenyl group.

The alkylene group may have a branch. The carbon number of the alkylene group is preferably from 1 to 12, more preferably from 2 to 10, most preferably from 2 to 8.

The alkylene moiety substituted for the alkylene group is the same as the alkylene group. As an example of the substituent, a halogen atom is included.

The alkenyl group can have a branch. The carbon number of the alkenyl group is preferably from 2 to 12, more preferably from 2 to 10, most preferably from 2 to 8.

The alkylene moiety substituted for the alkylene group is the same as the alkylene group. As an example of the substituent, a halogen atom is included.

An alkynyl group can have a branch. The carbon number of the alkynyl group is preferably from 2 to 12, more preferably from 2 to 10, most preferably from 2 to 8.

The alkynyl moiety of the substituted alkynyl group is the same as the alkynyl group. As an example of the substituent, a halogen atom is included.

Specific examples of the divalent chain group include an ethyl group, a trimethylene group, a propyl group, a tetramethylene group, a 2-methyl-tetramethylene group, a pentamethylene group, and a hexamethylene group. Octamethyl, 2-butenyl, 2-butenyl and the like.

The definitions and examples of the divalent cyclic group are the same as the definitions and examples of Cy ¹ , Cy ² and Cy ³ which will be described later.

In the formula (1), L ² or L ³ are each independently a single bond or a divalent linking group. L ² and L ³ are each independently preferably selected from the group consisting of -O-, -S-, -CO-, -NR-, -C=N-, a divalent chain group, a divalent cyclic group, and the like. A divalent linking group or a single bond of a group consisting of the combinations. R is an alkyl group having 1 to 7 carbon atoms or a hydrogen atom, preferably an alkyl group having 1 to 4 carbon atoms or a hydrogen atom, more preferably a methyl group, an ethyl group or a hydrogen atom, most preferably hydrogen. atom. The divalent chain group and the divalent cyclic group have the same definitions as L ¹ and L ⁴ .

Preferred divalent linking groups as L ² or L ³ may be exemplified by -COO-, -OCO-, -OCOO-, -OCONR-, -COS-, -SCO-, -CONR-, -NRCO-, - CH ₂ CH ₂ -, -C=C-COO-, -C=N-, -C=NN=C-, and the like.

In the formula (1), n is 0, 1, 2 or 3. When n is 2 or 3, the two L ³ may be the same or different, and the two Cy ² may be the same or different. n is preferably 1 or 2, more preferably 1.

In the formula (1), Cy ¹ , Cy ² and Cy ³ are each independently a divalent cyclic group.

The ring contained in the cyclic group is preferably a 5-membered ring, a 6-membered ring, or a 7-membered ring, more preferably 5 Member ring or 6-member ring, the best is 6-member ring.

The ring contained in the cyclic group may be a condensed ring. Among them, a single ring is more preferable than a condensed ring.

The ring contained in the cyclic group may be any of an aromatic ring, an aliphatic ring, and a hetero ring. Examples of the aromatic ring include a benzene ring and a naphthalene ring. Examples of the aliphatic ring include a cyclohexane ring. Examples of the heterocyclic ring include a pyridine ring and a pyrimidine ring.

As the cyclic group having a benzene ring, a 1,4-phenyl group is preferred. As the cyclic group having a naphthalene ring, a naphthalene-1,5-diyl group and a naphthalene-2,6-diyl group are preferred. As the cyclic group having a cyclohexane ring, a 1,4-cyclohexylene group is preferred. As the cyclic group having a pyridine ring, a pyridine-2,5-diyl group is preferred. As the cyclic group having a pyrimidine ring, a pyrimidine-2,5-diyl group is preferred.

The cyclic group may have a substituent. Examples of the substituent include a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 5 carbon atoms, a halogen-substituted alkyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms. An alkylthio group having 1 to 5 carbon atoms, a decyloxy group having 2 to 6 carbon atoms, an alkoxycarbonyl group having 2 to 6 carbon atoms, an amine methyl sulfonyl group, and 2 to 6 carbon atoms. The alkyl-substituted amine mercapto group and the mercaptoamine group having 2 to 6 carbon atoms.

In the following, an example of the polymerizable rod-like liquid crystal compound represented by the formula (1) is shown, but examples of the polymerizable rod-like liquid crystal compound are not limited to these examples.

[Chemical 2]

[Chemical 3]

[Chemical 4]

[Chemical 5]

In addition, as the rod-like liquid crystal compound, in addition to the polymerizable rod-like liquid crystal compound represented by the formula (1), at least one compound represented by the following formula (2) is preferably used in combination.

General formula (2) M ¹ -(L ¹ )p-Cy ¹ -L ² -(Cy ² -L ³ )n-Cy ³ -(L ⁴ )qM ²

(In the formula (2), M ¹ and M ² each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a heterocyclic group, a cyano group, a halogen, - SCN, -CF ₃ , nitro, or Q ¹ , but at least one of M ¹ and M ² represents a group other than Q ¹ .

Here, Q ¹ , L ¹ , L ² , L ³ , L ⁴ , Cy ¹ , Cy ² , Cy ³ and n are synonymous with the group represented by the formula (1). In addition, p and q are 0 or 1. )

When M ¹ and M ² do not represent Q ¹ , M ¹ and M ^{2 are} preferably a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a cyano group, more preferably carbon. The alkyl group having 1 to 4 or a phenyl group, p and q are preferably 0.

In addition, a preferable mixing ratio (mass ratio) of the compound represented by the formula (2) in the mixture of the polymerizable liquid crystal compound represented by the formula (1) and the compound represented by the formula (2), It is 0.1% to 40%, more preferably 1% to 30%, and particularly preferably 5% to 20%.

Hereinafter, preferred examples of the compound represented by the formula (2) are shown, but the invention is not limited to the examples.

[Chemical 6]

[Chemistry 7]

Discotic liquid crystal compounds are described in various literatures (C. Distolan, etc., Sub-crystal liquid crystals, Vol. 71, p. 111 (1981) (C. Destrade et al., Mol. Cryst. Liq. Cryst., vol. 71, page 111 (1981)); edited by the Chemical Society of Japan, "Quarterly Chemicals "Review", No. 22, "Chemistry of Liquid Crystals", Chapter 5, Chapter 10, Section 2 (1994); B. Cohen et al., "Chemical Communication of the German Society for Applied Chemistry", p. 1794 (1985) (B. Kohne et al., Angew. Chem. Soc. Chem. Comm., page 1794 (1985)); J. Zhang et al., American Chemical Society, Vol. 116, p. 2655 (1994) (J. Zhang et Al., J. Am. Chem. Soc., vol. 116, page 2655 (1994))). The polymerization of the discotic liquid crystal compound is described in Japanese Laid-Open Patent Publication No. Hei 8-27284. In order to fix the disc-shaped alignment layer liquid crystal compound by polymerization, a polymerizable group in which a disc-shaped core of a discotic liquid crystal compound is bonded as a substituent is required. However, if a polymerizable group is directly bonded to the disc-shaped core, it is difficult to maintain the alignment state in the polymerization reaction. Therefore, a linking group is introduced between the disk-shaped core and the polymerizable group. In other words, the photocurable discotic liquid crystal compound is preferably a compound represented by the following formula (3).

General formula (3)D(-L-P)n

(In the formula, D is a discotic core, L is a divalent linking group, P is a polymerizable group, and n is an integer of 4 to 12.)

Preferred specific examples of the disc-shaped core (D), the divalent linking group (L), and the polymerizable group (P) in the formula (3) are respectively disclosed in JP-A No. 2001-48837. In the descriptions (D1) to (D15), (L1) to (L25), and (P1) to (P18), the contents described in Japanese Laid-Open Patent Publication No. 2001-48837 can be preferably used.

In addition, as the discotic liquid crystal compound, a compound represented by the formula (DI) described in JP-A-2007-2220 is also preferably used.

The liquid crystal compound is contained in an amount of 80% by mass or more, 90% by mass or more, or 95% by mass or more, and 99.99% by mass or less, 99.98% by mass or less, and 99.97 mass, based on the mass of the solid content of the polymerizable composition (the mass of the solvent to be removed). % below. Particularly preferably, the compound containing an acrylic group or a methacryl group contains 70% by mass or more, 80% by mass or more, 90% by mass or more, or 95% by mass or more, and 99.99% by mass or less, 99.98% by mass or less, and 99.97% by mass. %the following.

The liquid crystal compound can be fixed in any of the alignment states of the horizontal alignment, the vertical alignment, the oblique alignment, and the twist alignment. In the present specification, the term "horizontal alignment" means that the long axis of the molecule is parallel to the horizontal plane of the transparent support in the case of a rod-like liquid crystal, and the circle of the core of the discotic liquid crystal compound in the case of a discotic liquid crystal. The disk surface is parallel to the horizontal plane of the transparent support, but is not required to be strictly parallel. In the present specification, it refers to an alignment angle with the horizontal plane of less than 10 degrees. The optically anisotropic layer which can be used in the present invention preferably contains a state in which the rod-like liquid crystal compound is horizontally aligned.

[solvent]

As the solvent to be used in the preparation of the coating liquid when the composition containing the liquid crystal compound is prepared as a coating liquid, an organic solvent or water or a mixed solvent of these may be preferably used. As an example of the organic solvent, guanamine (for example, N, N-dimethyl Mercaptoamine), anthracene (eg dimethylhydrazine), heterocyclic compound (eg pyridine), hydrocarbon (eg benzene, hexane), alkyl halide (eg chloroform, dichloromethane), ester (eg acetic acetate) Ester, butyl acetate), ketone (such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone), ether (such as tetrahydrofuran, 1,2-dimethoxyethane), alkyl alcohol (eg methanol, ethanol, propanol). Further, two or more solvents may be mixed and used. Among them, a halogenated alkane, an ester, a ketone, and a mixed solvent of these are preferable.

[Alignment fixation]

The fixation of the alignment of the liquid crystal compound is preferably carried out by a crosslinking reaction introduced into the polymerizable group of the liquid crystal compound, and more preferably by a polymerization reaction of a polymerizable group. The polymerization reaction includes a thermal polymerization reaction using a thermal polymerization initiator and a photopolymerization reaction using a photopolymerization initiator. The polymerization reaction may be either a radical polymerization or a cationic polymerization, but is preferably a radical polymerization. Examples of the radical photopolymerization initiator include: α-carbonyl compound (described in each specification of U.S. Patent No. 2,276,661, U.S. Patent No. 2,367,670), alcohol ketone ether (described in U.S. Patent No. 2,448,828), and α-hydrocarbon-substituted aromatic alcohol. a ketone compound (described in the specification of U.S. Patent No. 2,722,512), a polynuclear ruthenium compound (described in each specification of U.S. Patent No. 3,046,127, U.S. Patent No. 2,591,758), a combination of a triaryl imidazole dimer and a p-aminophenyl ketone (U.S. Patent No. 3,549,367) In the specification, acridine and a phenazine compound (described in Japanese Patent Laid-Open Publication No. SHO 60-105667, No. 4,239,850) and an oxadiazole compound (described in the specification of U.S. Patent No. 4,212,970). Examples of the cationic photopolymerization initiator include an organic onium salt system, an onium salt system, a phosphonium salt system, and the like, and an organic phosphonium salt system is preferred, and a triphenylsulfonium salt is particularly preferred. As a counter ion of the compound, It can be preferably used: hexafluoroantimonate, hexafluorophosphate or the like.

The radical thermal polymerization initiator is a compound which generates a radical by heating to a temperature higher than the decomposition temperature. Examples of such a radical thermal polymerization initiator include dioxane peroxide (ethyl peroxide, benzamidine peroxide, etc.), and ketone peroxide (methyl ethyl ketone peroxide, cyclohexanone peroxide). Etc., hydrogen peroxide (hydrogen peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, etc.), dialkyl peroxide (di-tert-butyl peroxide, dicumyl peroxide, peroxidation) Bismuth, etc.), peroxyesters (tert-butyl peroxyacetate, tert-butyl peroxypivalate, etc.), azo compounds (azobisisobutyronitrile, azobisisoprene, etc.) ), persulfates (ammonium persulfate, sodium persulfate, potassium persulfate, etc.).

The amount of the polymerization initiator to be used is preferably 0.01% by mass to 20% by mass, and more preferably 0.5% by mass to 5% by mass based on the solid content of the coating liquid. The light irradiation for photopolymerization of the liquid crystal compound is preferably ultraviolet light. The irradiation energy is preferably from 10 mJ/cm ² to 10 J/cm ² , more preferably from 25 mJ/cm ² to 1000 mJ/cm ² . Illuminance is preferably ^{10mW / cm 2 ~ 2000mW / cm} 2, more preferably ^{20mW / cm 2 ~ 1500mW / cm} 2, particularly preferably ^{40mW / cm 2 ~ 1000mW / cm} 2. The irradiation wavelength preferably has a peak at 250 nm to 450 nm, and more preferably has a peak at 300 nm to 410 nm. In order to promote the photopolymerization reaction, light irradiation may be carried out under an inert gas atmosphere such as nitrogen or under heating.

The heating for the thermal polymerization of the liquid crystal compound is preferably carried out at a temperature ranging from 50 ° C to 200 ° C for 10 minutes to 30 hours.

[Horizontal alignment agent]

In the polymerizable composition containing a liquid crystal compound, the formula (1) to the formula (3) described in the paragraph "0098" to the paragraph "0105" of JP-A-2009-69793 are used. At least one of the compound of the formula and the fluorine-containing homopolymer or copolymer of the monomer of the formula (4) allows the molecules of the liquid crystal compound to be substantially horizontally aligned. When the liquid crystal compound is horizontally aligned, the inclination angle thereof is preferably from 0 to 5 degrees, more preferably from 0 to 3 degrees, particularly preferably from 0 to 2 degrees, and most preferably from 0 to 1 degree.

The amount of the horizontal alignment agent to be added is preferably 0.01% by mass to 20% by mass, more preferably 0.01% by mass to 10% by mass, even more preferably 0.02% by mass to 1% by mass based on the mass of the liquid crystal compound. In addition, the compounds represented by the formulae (1) to (4) described in the paragraphs "0098" to "0105" of the Japanese Patent Laid-Open Publication No. 2009-69793 may be used singly or in combination of two or more kinds.

[Other additives]

The polymerizable composition containing a liquid crystal compound may include the onium salt described in paragraphs 0121 to 0148 of JP-A-2013-050583, and the formula (I) described in JP-A-2006-113500 The pyridinium compound shown. The onium salt functions as a vertical alignment agent on the interface side of the alignment layer. For example, the molecules of the discotic liquid crystalline compound can be aligned substantially vertically in the vicinity of the alignment layer. In addition, the polymerizable composition containing a liquid crystal compound may include a boric acid compound represented by the formula (I) described in JP-A-2013-054201.

The polymerizable composition containing a liquid crystal compound may contain a necessary additive, but preferably does not contain a so-called chiral agent.

[Coating method]

The coating of the optically anisotropic layer can be applied by dip coating, air knife coating, spin coating, slit coating, curtain coating, roll coating, and wire. This is carried out by bar coating, gravure coating or extrusion coating (U.S. Patent No. 2,681,294). It is also possible to apply two or more layers at the same time. The method of simultaneous coating is described in U.S. Patent No. 2,761,791, U.S. Patent No. 2,419,898, U.S. Patent No. 3,508, 947, U.S. Patent No. 3,526, 528, and the "Coating Engineering", 253 pages, Asakura Bookstore (1973) )in.

[temporary support]

The temporary support is not particularly limited, and may be a rigid or flexible one, and is preferably flexible in terms of ease of handling. The rigid support is not particularly limited, and examples thereof include a soda lime glass plate having a yttrium oxide film on the surface, a low-expansion glass, an alkali-free glass, a quartz glass plate, and the like, and an aluminum plate, an iron plate, and a stainless steel (SUS). ) Metal plates such as plates, resin plates, ceramic plates, slate, etc. The flexible support is not particularly limited, and examples thereof include cellulose esters (for example, cellulose acetate, cellulose propionate, cellulose butyrate), and polyolefins (for example, norbornene-based polymers). ), poly(meth) acrylate (such as polymethyl methacrylate), polycarbonate, polyester (such as polyethylene terephthalate or polyethylene naphthalate), polyfluorene, and ring Olefin polymer (for example, SNONEX, ZEONOR manufactured by ZEON Co., Ltd., ARTON manufactured by Japan Synthetic Rubber (JSR) Co., Ltd.), etc., plastic film or paper, aluminum foil, cloth Wait. More preferably, it is polyethylene terephthalate (PET). The film thickness of the rigid support is preferably from 100 μm to 3000 in terms of ease of handling. Μm, more preferably 300 μm to 1500 μm. The film thickness of the flexible support may be about 5 μm to 1000 μm, preferably 10 μm to 250 μm, and more preferably 15 μm to 90 μm.

[Alignment layer]

The alignment layer may be provided on the temporary support or on the surface of the undercoat layer coated on the temporary support. The alignment layer functions to define the alignment of the liquid crystal compound in the polymerizable composition provided thereon. The alignment layer may be an arbitrary layer if it imparts an alignment property to the optically anisotropic layer. It can be selected not only from a known material as a vertical alignment film but also from a known material as a horizontal alignment film. Examples of the alignment layer include a layer containing an organic compound (preferably a polymer), and light having an alignment property of liquid crystal represented by an azobenzene polymer or a polyvinyl cinnamate by polarized light irradiation. An alignment layer, an oblique vapor deposition layer of an inorganic compound, and a micro-groove layer, and further, ω-tetracosanoic acid, di-octadecylmethylammonium chloride, and methyl stearate A built-up film formed by the Langmuir-Blodgett method (LB film), or a layer in which a dielectric is aligned by applying an electric field or a magnetic field. As the alignment layer, a polymer layer is preferred, and a polymer layer containing modified or unmodified polyvinyl alcohol is particularly preferred. The modified or unmodified polyvinyl alcohol can also be used as a horizontal alignment film, but by adding a ruthenium compound to the optically anisotropic layer-forming composition, the action of the ruthenium compound and the alignment film can be The action of the ruthenium compound and the liquid crystal compound or the like causes the liquid crystal molecules to be aligned at an alignment angle of the alignment film at a high average tilt angle or in a vertical alignment state. Modified polyvinyl alcohol is at least one hydroxyl group of polyvinyl alcohol by functional The modification of the group includes, for example, a modification in which polyvinyl alcohol is exemplified by an ethyl acetonitrile group, a sulfonic acid group, a carboxyl group, an alkyloxy group or the like. As the alignment film, it is preferred to use an alignment film containing a modified polyvinyl alcohol containing a unit having a polymerizable group. The reason is that the adhesion to the optically anisotropic layer can be further improved. Further, a polyvinyl alcohol in which at least one hydroxyl group is substituted with a group having a vinyl moiety, an oxyheteropropyl moiety or an aziridine moiety is preferred, and for example, paragraph number [0071 of Japanese Patent No. 3907735 is preferably used. The modified polyvinyl alcohol described in paragraph No. [0095].

The thickness of the alignment layer is preferably from 0.01 μm to 5 μm, more preferably from 0.05 μm to 2 μm.

It is preferred to subject the alignment layer to a rubbing treatment and to provide an optically anisotropic layer on the rubbed surface. The rubbing treatment applied to the alignment layer can be usually carried out by wiping the surface of the film mainly composed of the polymer in a certain direction with paper or cloth. A general method of the rubbing treatment is described, for example, in "Liquid Crystal Handbook" (published by Maruzen Co., Ltd., October 30, 2000).

As a method of changing the friction density, a method described in "Liquid Crystal Handbook" (published by Maruzen Co., Ltd.) can be used. The friction density (L) is quantified by the following formula (A).

Formula (A) L=N1(1+2πrn/60v)

In the formula (A), N is the number of rubbing, 1 is the contact length of the rubbing roll, r is the radius of the roll, n is the number of revolutions (rpm) of the roll, and v is the moving speed of the stage (second speed).

In order to increase the friction density, it is only necessary to increase the number of frictions, increase the contact length of the friction roller, increase the radius of the roller, increase the rotation speed of the roller, and slow down the moving speed of the platform. On the other hand, in order to reduce the friction density, The opposite operation is fine.

Further, as a condition at the time of the rubbing treatment, the description of Japanese Patent No. 4052558 can also be referred to.

[other functional layers]

The transfer material or the polarizing plate may include other functional layers such as a low moisture permeable layer, a protective layer, an antistatic layer, a hard coat layer, an adhesive layer, a release layer, a release layer, and the like in addition to the layer.

The transfer material may include other functional layers, but the manufacturing method of the present invention is characterized in that the transfer material does not include a layer which is directly coated on the optically anisotropic layer or a polymerizable composition containing a liquid crystal compound. The polymer layer formed by the composition of the surface may be transferred to the polarizing element (the transfer body and the film containing the polarizing element are bonded). For example, even if the optically isotropic acrylic polymer layer formed by the following method is not included, the optically anisotropic layer may be transferred onto the film including the polarizing element: directly coated on the optically anisotropic layer or The polymerizable composition containing the (meth) acrylate on the surface of the layer formed of the polymerizable composition containing the liquid crystal compound is cured.

Release layer

The release layer is provided between the temporary support and the alignment layer, and in the production method of the present invention, is a layer which is peeled off from the temporary support together with the transfer material. By using demolding In the layer, the release between the release layer and the adjacent layer (alignment layer or the like) formed on the opposite side of the temporary support from the release layer is stabilized, and the transfer property at the time of transfer can be improved.

As the release layer, a release resin, a resin containing a release agent, a curable resin which is crosslinked by light irradiation, or the like can be applied. Examples of the mold release resin include a fluorine resin, an anthrone, a melamine resin, an epoxy resin, a polyester resin, an acrylic resin, and a cellulose resin. Preferred examples thereof include a melamine resin. Examples of the resin containing the release agent include an acrylic resin, a vinyl resin, a polyester resin, and a cellulose resin obtained by adding a release agent such as a fluorine resin, an anthrone or various waxes or copolymerizing them.

The formation of the release layer may be carried out by dispersing or dissolving the resin in a solvent, and applying it by a known coating method such as roll coating or gravure coating. Further, if necessary, it can be dried by heating at a temperature of 30 ° C to 120 ° C, or aged, or irradiated with ionizing radiation to crosslink. The thickness of the release layer is usually about 0.01 μm to 5.0 μm, preferably about 0.5 μm to 3.0 μm.

Peeling layer

The peeling layer is provided between the temporary support and the alignment layer, and in the manufacturing method of the present invention, the outermost layer of the transfer body obtained by peeling off the temporary support from the transfer material. The peeling of the temporary support from the transfer material is stabilized by using the release layer.

Since the release layer is the outermost surface of the transfer body, it is preferably provided with surface protection. The material of the release layer is an adhesive layer having a peeling property to the temporary support and an adjacent layer (alignment layer, patterned optical anisotropic layer, etc.) formed on the opposite side of the temporary support from the peeling layer. Sex is not particularly limited, for example Can be used: acrylic resin, vinyl chloride-vinyl acetate copolymer resin, polyester resin, polymethacrylate resin, polyvinyl chloride resin, cellulose resin, fluorenone resin, chlorinated rubber, casein, metal oxide Things and so on. These materials may be used in combination of two or more kinds. Further, a fluorine-based resin, an anthrone, a release agent such as various waxes, various surfactants, or the like may be added to the material or may be copolymerized.

In the transfer material, it is also preferred that the alignment layer also serves as a release layer.

[Polarizing element]

Examples of the polarizing element include an iodine-based polarizing element, a dye-based polarizing element using a dichroic dye, and a polyene-based polarizing element. The iodine-based polarizing element and the dye-based polarizing element are usually produced by using a polyvinyl alcohol-based film. In the manufacturing method of the present invention, any of the polarizing elements can be used. For example, the polarizing element is preferably composed of modified or unmodified polyvinyl alcohol and dichroic molecules. For a polarizing element comprising a modified or unmodified polyvinyl alcohol and a dichroic molecule, for example, the description of JP-A-2009-237376 can be referred to. The film thickness of the polarizing element may be 50 μm or less, preferably 30 μm or less, and more preferably 20 μm or less. Further, the film thickness of the polarizing element is usually 1 μm or more, 5 μm or more, or 10 μm or more.

[Manufacturing method of polarizing plate]

In the manufacturing method of the present invention, the temporary support is peeled off between the temporary support of the transfer material and the alignment layer, and then the temporary support of the transfer body obtained by peeling the temporary support from the transfer material is provided. The surface after peeling of the body may be adhered to the film including the polarizing element.

The peeling method of the temporary support is not specifically limited. Temporary support peeling Good is carried out at a speed at which the transfer body does not break.

When the prepared transfer material is larger than the produced polarizing plate, the transfer material can be cut before the peeling of the temporary support. The example with a width of more than 1.5m transfer material cut roll, and cut into a 0.1m ² or less, 0.05m ² or less, 0.03m ² or less, 0.025m ² or less, 0.02m ² or less, 0.01m ² or less Any shape such as a square or a rectangle having a size of 0.005 cm ² or less or 0.003 m ² or less. The lower limit of the shape is not particularly limited, and may be any size as long as it is operable, and may be usually about 0.0001 m ² (1 cm ² ) or more.

The outermost surface of the transfer body is preferably an alignment layer. The outermost surface of the transfer body may be bonded to a polarizing element in a film including a polarizing element, or may be bonded to a layer other than the polarizing element, but is preferably bonded to the polarizing element. Particularly preferably, the outermost surface of the transfer body is an alignment layer, and the alignment layer is bonded to the polarizing element. In this case, when the alignment layer is a layer containing polyvinyl alcohol and the polarizing element is a polyvinyl alcohol, the adhesion is particularly excellent.

In the present specification, when it is called bonding, it may be bonded or adhered. Adhesion can be carried out only via the adhesive layer. The adhesive layer may be a layer containing an adhesive or an adhesive. That is, the transfer body and the film including the polarizing element may be adhered or adhered by an adhesive or an adhesive.

The adhesive is not particularly limited, and examples thereof include a polyvinyl alcohol-based adhesive, an aqueous solution of a boron compound, and an epoxy compound having no aromatic ring in the molecule as disclosed in JP-A-2004-245925. A photopolymerization initiator having a molar absorption coefficient of 400 or more at a wavelength of 360 nm to 450 nm and an ultraviolet curable compound, as described in Japanese Laid-Open Patent Publication No. 2008-174667. In the total amount of the (meth)acrylic compound, 100 parts by mass of the (meth)acrylic compound described in JP-A-2008-174667, (a) has two in the molecule, as described in JP-A-2008-174667. a (meth)acrylic compound having (meth)acrylonitrile group, (b) a (meth)acrylic compound having a hydroxyl group in a molecule and having only one polymerizable double bond, and (c) a phenol ring An active energy ray-curing adhesive such as oxyethylene modified acrylate or nonyl phenol ethylene oxide modified acrylate.

Among them, a polyvinyl alcohol-based adhesive is particularly preferred. Further, the polyvinyl alcohol-based adhesive is an adhesive containing modified or unmodified polyvinyl alcohol. The polyvinyl alcohol-based adhesive may contain a crosslinking agent in addition to the modified or unmodified polyvinyl alcohol. Specific examples of the binder include an aqueous solution of polyvinyl alcohol or polyvinyl acetal (for example, polyvinyl butyral) or a vinyl polymer (for example, polyvinyl chloride, polyvinyl acetate, and polybutyl acrylate). ) Latex. A particularly preferred adhesive is an aqueous solution of polyvinyl alcohol. At this time, the polyvinyl alcohol is preferably a completely saponified person.

The thickness of the adhesive layer is preferably from 0.01 μm to 10 μm, particularly preferably from 0.05 μm to 5 μm, in terms of dry film thickness.

[Film containing polarizing element]

The film including the polarizing element that bonds the transfer body may include only the polarizing element, or may include other layers such as a protective film in addition to the polarizing element.

[Protective film (protective layer)]

The polarizing plate preferably contains a protective film. For example, a protective film may be provided on either or both sides of the polarizing element to form a film including the polarizing element. In addition, in the transfer material In the material, a protective film may be provided in advance on the side opposite to the temporary support side as viewed from the alignment layer. Alternatively, after the transfer body is bonded to the film including the polarizing element, a protective film may be provided on either one side or both sides.

The protective film can be provided, for example, by directly applying a composition for forming a protective film to a surface on which a protective film is provided, and drying, etc., in such a manner as to be in direct contact with other layers, usually by using an adhesive or an adhesive. It can be attached to the surface. As the adhesive or the adhesive, it is sufficient to use the same adhesive or adhesive as used for bonding the transfer body to the film containing the polarizing element.

As the protective film, a deuterated cellulose polymer film, an acrylic polymer film, or a cycloolefin polymer film can be used. For the deuterated cellulose-based polymer, the description of the deuterated cellulose-based resin disclosed in JP-A-2011-237474 can be referred to. For the cycloolefin polymer film, the descriptions of JP-A-2009-175222 and JP-A-2009-237376 can be referred to. The polarizing plate can be provided with moisture permeability by including a cycloolefin polymer film. The term "moisture permeability" refers to the property of not passing water but passing water vapor.

The film thickness of the protective film may be 100 μm or less, 50 μm or less, 30 μm or less, 20 μm or less, or 10 μm or less, and may be 1 μm or more, 5 μm or more, or 10 μm or more.

[hard coating]

The polarizing plate may comprise a hard coat layer. The hard coat layer may be contained as the outermost layer of the polarizing plate, and is preferably the outermost layer included on the side of the optically anisotropic layer when viewed from the polarizing element.

In the present specification, the term "hard coat layer" means a layer in which the pencil hardness of the transparent support is increased by forming the layer. Practically, the pencil hardness (JIS K5400) after lamination of the hard coat layer is preferably H or more, more preferably 2H or more, and most preferably 3H or more. The thickness of the hard coat layer is preferably from 0.4 μm to 35 μm, more preferably from 1 μm to 30 μm, most preferably from 1.5 μm to 20 μm.

For the specific composition, the description of Japanese Patent Laid-Open Publication No. 2012-103689 can be referred to.

[Examples]

Hereinafter, the present invention will be more specifically described by way of examples. The materials, reagents, masses, ratios, operations, and the like shown in the following examples can be appropriately changed without departing from the gist of the present invention. Therefore, the scope of the invention is not limited to the following embodiments.

<Preparation of Support 1 (Cellulose Acetate Membrane T1)>

The following composition was placed in a mixing tank, and while stirring, the components were dissolved to prepare a cellulose acetate solution.

Composition of cellulose acetate solution

In a separate mixing tank, 16 parts by mass of the following additive (A), 92 parts by mass of dichloromethane, and 8 parts by mass of methanol were charged, and the mixture was stirred while heating to prepare an additive (A) solution. 25 parts by mass of the additive (A) solution was mixed in 474 parts by mass of the cellulose acetate solution, and the mixture was sufficiently stirred to prepare a dope. The additive (A) was added in an amount of 6.0 parts by mass based on 100 parts by mass of the cellulose acetate.

The resulting dope was cast using a belt extension machine. After the film surface temperature of the belt was changed to 40 ° C, the film was dried by a warm air of 70 ° C for 1 minute, and the film was dried by a drying wind at 140 ° C for 10 minutes to prepare a fiber having a residual solvent amount of 0.3% by mass. Acetate film T1 (support 1).

The obtained long-length cellulose acetate film T1 had a width of 1490 mm and a thickness of 80 μm. Further, the in-plane retardation (Re) was 8 nm, and the retardation (Rth) in the thickness direction was 78 nm.

<Production of Transfer Material 1> (Formation of alignment film 1)

On the produced support, an alignment layer coating liquid having the following composition was continuously applied by a wire rod of #14. It was dried by a warm air of 60 ° C for 60 seconds, and then dried by a warm air of 100 ° C for 120 seconds. The modified polyvinyl alcohol used had a degree of saponification of 96.8%. The film thickness of the obtained alignment film was 0.5 μm.

Composition of coating liquid of alignment layer 1

(Orientation processing)

The support body on which the alignment layer is applied is subjected to a rubbing treatment on the surface of the alignment layer so as to be aligned in parallel with the conveyance direction. The rubbing roller was rotated at 450 rpm.

(Application of optical anisotropic layer 1)

The following composition was dissolved in 270 parts by mass of methyl ethyl ketone to prepare a coating liquid.

(Composition for forming an optically anisotropic layer 1)

[化10]

The prepared coating liquid was applied to the rubbing surface of the alignment layer 2 using a #2.8 wire bar. The coating amount was 4.8 mL/m ² . Then, it was heated in a thermostat at 120 ° C for 300 seconds to align the discotic liquid crystal compound. Then, a 160 W/cm high-pressure mercury lamp was used at 80 ° C, and ultraviolet rays were irradiated for 1 minute to carry out a crosslinking reaction, and the discotic liquid crystal compound was polymerized and immobilized to form an optically anisotropic layer, and a transfer material 1 was produced. The film thickness of the optically anisotropic layer was 0.8 μm, the liquid crystal pointing angle on the support side was 0°, and the liquid crystal pointing angle on the air interface side was 75°.

The film contrast ratio was 10,000, and there was no poor alignment and the adhesion was good. Film contrast, alignment failure, and adhesion were measured and evaluated by the following methods. Further, the liquid crystal compound of the optically anisotropic layer is subjected to reverse mixing and alignment.

<Production of Transfer Material 2> (formation of alignment layer 2)

On the support 1, the alignment layer coating liquid of the following composition was continuously applied by a wire rod of #14. It was dried by a warm air of 60 ° C for 60 seconds, and then dried by a warm air of 100 ° C for 120 seconds. The thickness of the obtained alignment film was 0.5 μm.

Composition of the alignment layer coating liquid

[11]

A rubbing treatment is continuously performed on the produced alignment layer. At this time, the longitudinal direction of the elongated film is parallel to the conveyance direction, and the rotation axis of the rubbing roller is set to rotate clockwise by 45° with respect to the film longitudinal direction.

(Formation of Optically Anisotropic Layer 2)

The coating amount of the liquid crystal compound-containing coating liquid having the following composition was changed so that the value of Re(0) measured by KOBRA21 ADH was 125 nm, and the friction surface of the produced alignment layer 2 was continuously continuous by a wire rod. Coating. The film transport speed (V) was set to 20 m/min. In order to dry the solvent of the coating liquid and the aging of the discotic liquid crystal compound, it was heated by a warm air of 130 ° C for 90 seconds. Then, ultraviolet (Ultraviolet, UV) irradiation was performed at 80 ° C to form an optically anisotropic layer 2 with an alignment layer, and a transfer material 2 was obtained. The film thickness of the optically anisotropic layer was 1.0 μm.

Composition of coating liquid of optically anisotropic layer 2

"95" and "5" in the structural formulas of "25", "25", "50", and the fluorine-based polymer (FP2) in the structural formula of the fluorine-based polymer (FP1) indicate a polymer. The repeating unit of the molar ratio.

The direction of the slow axis of the produced optical anisotropic layer 2 is orthogonal to the rotation axis of the rubbing roller. That is, the slow axis is a direction rotated by 45° clockwise with respect to the longitudinal direction of the support. In the same manner as in Comparative Example 1, it was confirmed that the disk surface of the discotic liquid crystalline molecule had an average tilt angle with respect to the film surface of 90°, and the discotic liquid crystal was vertically aligned with respect to the film surface.

<Production of Transfer Material 3>

The surface of the alignment layer 2 of the laminate 1 of the support 1 and the alignment layer 2 formed in the same manner as in the case of producing the transfer material 2 is subjected to a rubbing treatment in the same manner as in the case of producing the transfer material 2 . On the rubbing treatment surface, the coating liquid shown below was applied using a wire bar, dried at room temperature for 30 seconds, and then heated at 90 ° C for 2 minutes, and then melted by a D valve ( Light 90mW/cm) with 60% output for 6 seconds~12 The optical anisotropic layer 3 was produced in seconds. The film thickness of the optically anisotropic layer was 1.2 μm. It was confirmed that the average tilt angle of the rod-like liquid crystal compound with respect to the film surface was 0°, and the rod-like liquid crystal was horizontally aligned with respect to the film surface.

<Production of Transfer Material 4> (Formation of Optically Anisotropic Layer 4)

The surface of the alignment layer 2 of the laminate 1 of the support 1 and the alignment layer 2 formed in the same manner as in the case of producing the transfer material 2 is subjected to a rubbing treatment in the same manner as in the case of producing the transfer material 2 . On the rubbing treatment surface, the following dissolution was applied by a wire rod of #2 The solution is 1.8 g of the following rod-like liquid crystal compound, 0.06 g of a photopolymerization initiator (Irgacure-907, manufactured by BASF Corporation), and a sensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.) 0.02 g. The following air interface side vertical alignment agent 0.002 g was dissolved in 9.2 g of cyclohexane/cyclopentanone (=65/35 (% by mass)). The friction surface coated with the solution was attached to a metal frame, and heated in a thermostat at 100 ° C for 2 minutes to align the rod-like liquid crystal compound. Then, the rod-like liquid crystal compound was crosslinked by using a 120 W/cm high pressure mercury lamp at 100 ° C for 30 seconds of UV irradiation. Then, it was left to cool to room temperature to form the optically anisotropic layer 4. The film thickness of the optically anisotropic layer was 1.3 μm.

<Production of Transfer Material 5>

The optically anisotropic layer 5 is produced by the following optical anisotropic layer 5-1 and optically anisotropic layer 5-2.

In the same manner as in the case of producing the transfer material 1, a laminate of the support 1 and the alignment layer 1 is produced, and the alignment layer 1 is continuously subjected to a rubbing treatment. At this time, the longitudinal direction of the elongated film is parallel to the conveying direction, and the angle between the longitudinal direction of the film and the rotating shaft of the rubbing roller is 75° (clockwise rotation) (if the film length direction is set to 90°, the friction is applied. The axis of rotation of the roller is 15°).

(Formation of Optically Anisotropic Layer 5-1)

On the rubbing surface of the alignment layer 1 described above, a coating liquid of the optically anisotropic layer 5-1 containing a discotic liquid crystal compound having the following composition was continuously applied by a wire rod of #5. In order to dry the solvent of the coating liquid and the aging of the discotic liquid crystal compound, it is heated by a warm air of 115 ° C for 90 seconds, followed by heating by a warm air of 80 ° C for 60 seconds, and UV irradiation at 80 ° C. And the alignment of the liquid crystal compound is fixed. The thickness of the obtained optical anisotropic layer 5-1 was 2.0 μm. It was confirmed that the average tilt angle of the disk surface of the discotic liquid crystal compound with respect to the film surface was 90°, and the discotic liquid crystal compound was vertically aligned with respect to the film surface. Further, the angle of the slow axis is 15° when it is parallel to the rotation axis of the rubbing roller and the film length direction is 90° (the film width direction is set to 0°).

Composition of coating liquid of optically anisotropic layer 5-1

[化15]

(Formation of Optically Anisotropic Layer 5-2)

The optically anisotropic layer 5-1 thus produced was continuously subjected to a rubbing treatment. At this time, the longitudinal direction of the long film is parallel to the conveyance direction, and the angle between the film length direction and the rotation axis of the rubbing roller is -75° (counterclockwise rotation) (if the film length direction is 90°, The friction roller has a rotation axis of 165°).

On the optically anisotropic layer 5-1 subjected to the rubbing treatment, a coating liquid of the following composition was continuously applied by a wire rod of #2.2. In order to dry the solvent of the coating liquid and the aging of the rod-like liquid crystal compound, UV irradiation was performed at 60 ° C for 60 seconds by warm air at 60 ° C to fix the alignment of the liquid crystal compound. Income The thickness of the optically anisotropic layer 5-2 was 0.8 μm. The laminated body of the optical anisotropic layer 5-1 and the optical anisotropic layer 5-2 is referred to as an optical anisotropic layer 5. It was confirmed that the average tilt angle of the long axis of the rod-like liquid crystal compound with respect to the film surface was 0°, and the liquid crystal compound was horizontally aligned with respect to the film surface. Further, the angle of the slow axis is 75° when it is orthogonal to the rotation axis of the rubbing roller and the film length direction is 90° (the film width direction is set to 0°).

Composition of coating liquid of optically anisotropic layer 5-2

[Chemistry 16]

<Production of Transfer Material 6> (Formation of friction alignment layer)

The laminate of the support 1 and the alignment layer 1 is produced in the same manner as in the case of producing the transfer material 1, and the alignment layer 1 of the laminate is continuously subjected to a rubbing treatment. At this time, the longitudinal direction of the elongated film is parallel to the conveying direction, and the angle between the longitudinal direction of the film and the rotating shaft of the rubbing roller is set to 15° (clockwise rotation) (if the film length direction is set to 90°, the friction is applied. The axis of rotation of the roller is 75°).

In the same manner as the production of the transfer material 5, the coating liquid of the optically anisotropic layer 5-1 is changed to the coating liquid of the optical anisotropic layer 6-1 described below. A transfer material 6 including an optically anisotropic layer 6 (a laminate of the optically anisotropic layer 5-1 and the optically anisotropic layer 6-1) was produced.

Composition of coating liquid of optically anisotropic layer 6-1

<Production of Transfer Material 7 to Transfer Material 12>

The transfer material 7 to the transfer material 12 were obtained in the same manner as the transfer material 1 to the transfer material 6 except that the support 1 was changed to PET (thickness: 75 μm) manufactured by Fujifilm.

<Production of Polarizing Plate 1 to Polarizing Plate 12> (production of polarizing element)

The roll-shaped polyvinyl alcohol film having a thickness of 80 μm was continuously extended to 5 times in an aqueous iodine solution, and dried to obtain a polarizing film (polarizing element) having a thickness of 20 μm.

(Production of Acrylic Resin Sheet T2)

The acrylic resin described below was used. The acrylic resin can be obtained as a commercial product.

. Dianal BR88 (trade name), manufactured by Mitsubishi Rayon Co., Ltd., and having a mass average molecular weight of 1,500,000 (hereinafter referred to as acrylic resin AC-1).

(UV absorber)

The following ultraviolet absorbers were used.

. UV agent 1: TINUVIN 328 (manufactured by BASF)

(Preparation of concentrate B)

The following composition was placed in a mixing tank, stirred while heating, and each component was dissolved to prepare a dope B.

(composed of concentrated liquid B)

The prepared dope was uniformly cast from the casting die to a 2000 mm wide and stainless steel endless belt (casting support) using a casting apparatus. When the amount of the residual solvent in the dope was 40% by mass, the self-casting support was peeled off as a polymer film, and it was conveyed without stretching, and dried at 130 ° C in a drying zone. The obtained acrylic resin sheet T2 had a film thickness of 40 μm.

One side of the resin sheet T2 thus obtained was subjected to corona treatment, and on the corona-treated surface, polyvinyl alcohol (PVA) (manufactured by Kuraray Co., Ltd., PVA-117H) 3% aqueous solution was used. As an adhesive, it is bonded to one side of the polarizing element.

(deuterated cellulose film)

A commercially available deuterated cellulose film (Fujitac ZRD40, manufactured by Fujifilm Co., Ltd.) was immersed in a 1.5 mol/L NaOH aqueous solution (saponified solution) maintained at 55 ° C for 2 minutes, and then the membrane was washed with water, and then After immersing in a 0.05 mol/L aqueous solution of sulfuric acid at 25 ° C for 30 seconds, it was then passed through a water bath for 30 seconds under running water to make the film Neutral state. Then, the water was removed by air blasting three times, and the water was detached, and then dried in a drying zone at 70 ° C for 15 seconds to dry, thereby producing a saponified film.

PVA (manufactured by Kuraray Co., Ltd., PVA-117H) was 3% of the surface of the saponified cellulose-deposited cellulose film ZRD40 and the surface of the polarizing element bonded to the acrylic resin sheet. The aqueous solution is bonded as an adhesive so that the longitudinal direction of the roll of the produced polarizing element is parallel to the longitudinal direction of the roll of the bismuth cellulose film ZRD40.

The transfer material 1 to the transfer material 12 are cut into a 150 mm quadrangle, and the support T1 or the PET is slowly peeled off at the interface with the alignment layer to obtain a transfer body. After corona treatment of the ZRD40 surface of the obtained polarizing plate (film containing a polarizing element), the transfer body was used as a binder using polyvinyl alcohol (PVA-117H manufactured by Kuraray) 3% aqueous solution. A polarizing plate with an optically anisotropic layer is obtained by bonding to the alignment layer. In the case of using any of the transfer materials, the transfer body can be bonded to the film including the polarizing element without any problem. The obtained polarizing plates were used as the polarizing plates 1 to 12, respectively.

<Polarizing plate 13 to polarizing plate 24>

In addition, in the polarizing plate 1 to the polarizing plate 12, the acrylic resin sheet T2 which was corona-treated on the surface subjected to the corona treatment was attached to the surface of the polarizing element on one side, and the ZRD 40 was attached. The production is performed by the same method as the polarizing plate 1 to the polarizing plate 12, respectively.

(Production of cyclic olefin resin sheet T3)

The commercially available cycloolefin polymer film "ZEONOR ZF14" (manufactured by Nippon, Japan) was extended by the elongation temperature (Tg is the glass transition temperature of the cyclic olefin resin) and the stretching ratio shown in Table 4 below. The cyclic olefin resin sheet T3 was obtained.

<Polarizing plate 25 to polarizing plate 36>

In the polarizing plate 1 to the polarizing plate 12, the polarizing plate 1 to the polarizing plate 1 is replaced by the same method as the polarizing plate 1 to the polarizing plate 12, except that the obtained annular olefin resin sheet T3 is bonded to the ZRD 40. Plate 25 to polarizing plate 36.

<Polarizing plate 37 to polarizing plate 48>

The polarizing plate 37 to the polarizing plate 48 are obtained by the same method as the polarizing plate 1 to the polarizing plate 12 except that the polarizing plate 1 to the polarizing plate 12 are not provided with the ZRD 40. In other words, in the polarizing plate 37 to the polarizing plate 48, the optically anisotropic layer and the polarizing element are directly bonded to each other by using the same adhesive as described above.

(Comparative example) <Preparation of Polarizing Plate 49 to Polarizing Plate 60>

In the same manufacturing method as the polarizing plate 37 to the polarizing plate 48, the optical anisotropy of the transfer material 1 to the transfer material 12 before the temporary support (the support T1 or the PET) is peeled off Layer and polarizer (film containing polarizing element) Hehe. After the bonding, the temporary support is peeled off, and the obtained polarizing plates are used as the polarizing plates 49 to 60, respectively.

<Production of Polarizing Plate 61 to Polarizing Plate 66>

One side of the polarizing element and the resin sheet T2 was subjected to corona treatment, and on the corona-treated surface, a PVA (manufactured by Kuraray Co., Ltd., PVA-117H) 3% aqueous solution was used as an adhesive, and the polarizing element was used. Side fit. On the other surface, the same rubbing treatment as in the case of producing the transfer material 1 to the transfer material 6 is performed, and the optical treatment is performed on the rubbing treatment surface by the transfer material 1 to the transfer material 6 The formation of the opposite layer in the same order directly forms the optically anisotropic layer 1 to the optically anisotropic layer 6. The obtained polarizing plates were used as the polarizing plates 61 to 66, respectively.

(Adhesion evaluation)

On the surface of the polarizing plate 1 to the polarizing plate 48 on which the optically anisotropic layer including the alignment film is formed, a slit of 11 vertical and 11 vertical slits is cut into a grid by a dicing blade to engrave a total of 100 In the square lattice, the polyester tape "NO.31B" manufactured by Nitto Denko Co., Ltd. was pressure-bonded, and when the peeling was less than 20 grids in 100 grids, the adhesion test was performed at the same location. Perform up to 2 replicates. The presence or absence of peeling was observed by visual observation, and the following five levels of evaluation were performed. The presence or absence of peeling was observed by visual observation. The results are summarized in Table 3.

A: No peelers were found in 100 grids in 2 close tests.

B: peeled into 1 grid to 5 grids in 100 grids in 2 times of the adhesion test

C: peeled off from 6 grids to 19 grids in 100 grids in 2 close-contact tests

D: peeled out to 20 or more in 100 grids in the 2nd adhesion test

E: In a single adhesion test, the peeling is 20 or more in 100 grids.

1‧‧‧Polarized elements

2‧‧‧ Optical anisotropic layer

4‧‧‧Protective film 1

5‧‧‧hard coating

6‧‧‧Protective film 2

12‧‧‧Alignment layer

Claims (12)

A method of manufacturing a polarizing plate, comprising: preparing a transfer material, the transfer material sequentially comprising a temporary support, an alignment layer and an optically anisotropic layer, and the optically anisotropic layer is directly coated on a layer formed of a polymerizable composition of a liquid crystal compound of the alignment layer; the temporary support is peeled off between the temporary support of the transfer material and the alignment layer; and The peeled surface of the transfer body including the optically anisotropic layer and the alignment layer is bonded to a film including a polarizing element. The manufacturing method according to claim 1, wherein an outermost layer of the transfer body is the alignment layer, and the alignment layer is directly bonded to the film including the polarizing element. The manufacturing method according to claim 2, wherein the polarizing element in the film including the polarizing element is directly bonded to the alignment layer. The manufacturing method of claim 3, wherein the alignment layer comprises modified or unmodified polyvinyl alcohol. The manufacturing method according to any one of claims 1 to 4, wherein the polarizing element comprises modified or unmodified polyvinyl alcohol. The manufacturing method according to any one of claims 1 to 4, wherein the bonding of the transfer body to the film comprising the polarizing element comprises modifying or unmodified polyethylene. It is carried out with an alcohol binder. The manufacturing method according to any one of claims 1 to 4, wherein the preparation of the transfer material and the peeling of the temporary support include: cutting the transfer material into Step of an area of 0.025 m ² or less. The manufacturing method according to any one of claims 1 to 4, wherein the temporary support comprises a polyester. The manufacturing method of claim 8, wherein the temporary support comprises polyethylene terephthalate. The manufacturing method according to any one of claims 1 to 4, further comprising the manufacture of the transfer material by a manufacturing method comprising: directly on a surface of the alignment layer Coating the polymerizable composition containing a liquid crystal compound; and applying the obtained coating layer to light irradiation or heating. The production method according to any one of claims 1 to 4, wherein the optically anisotropic layer has a film thickness of 0.5 μm to 5 μm. The production method according to any one of claims 1 to 4, wherein the optically anisotropic layer has a film thickness of 0.5 μm to 3 μm.