JP6944587B2 - Method for producing polarizing plate, method for producing optical film, and polymerizable liquid crystal composition - Google Patents

Description

The present invention relates to a method for producing a polarizing plate, a method for producing an optical film, and a polymerizable liquid crystal composition.

The polarizing plate is used as a member of a liquid crystal display (LCD) and an organic light emitting diode (OLED), and plays an important role in its display performance.
Further, a general polarizing plate has a structure in which an optical film is attached to one or both sides of a polarizing film (polarizer) in which a dichroic dye such as an iodine complex is adsorbed and oriented on a polyvinyl alcohol (PVA) resin. have.
As such an optical film, a film having a retardation layer (optically anisotropic layer) in which a liquid crystal compound is coated on a transparent support via an alignment film and the alignment state is fixed has been conventionally used. It has been widely studied, and when such an optical film is bonded to a polarizer, a configuration in which the transparent support side of the optical film is bonded to the polarizer is common (for example, Patent Document 1). Etc.).

In recent years, from the viewpoint of further thinning the polarizing plate and widening the viewing angle, a configuration has been proposed in which the retardation layer (optical anisotropic layer) side of the optical film is bonded to the polarizer. A method of peeling off the transparent support after adhering the retardation layer (optically anisotropic layer) to the polarizer has also been proposed (see, for example, Patent Document 2).

JP-A-2007-249108 Japanese Unexamined Patent Publication No. 2012-220554

When the present inventors examined the polarizing element (polarizing plate) described in Patent Document 2, the organic silicon compound layer formed on the surface of the liquid crystal layer (optically anisotropic layer) on the polarizer side was omitted. If so, depending on the adhesive used, the orientation of the liquid crystal layer changes due to the penetration of the adhesive into the liquid crystal layer, and as a result, the display performance deteriorates when applied to an image display device, resulting in optical stability. It turned out to be inferior in sex. It was also found that the adhesion between the polarizer and the liquid crystal layer was insufficient depending on the adhesive used.

Therefore, the present invention provides a method for producing a polarizing plate, which has good adhesion between a polarizing element and an optically anisotropic layer and is excellent in optical stability when applied to an image display device, and a method for producing an optical film and polymerization. An object of the present invention is to provide a sex liquid crystal composition.

As a result of diligent studies to achieve the above problems, the present inventors use a semi-cured layer satisfying a predetermined curing profile for bonding with a polarizer, and after bonding, cure again to obtain an optically anisotropic layer. As a result, they have found that the adhesion between the polarizer and the optically anisotropic layer is good, and that a polarizing plate having excellent optical stability can be produced when applied to an image display device, and the present invention has been completed.
That is, it was found that the above-mentioned problems can be achieved by the following configuration.

[1] Formation of a layer on a substrate for forming a liquid crystal composition layer composed of a liquid crystal compound having a polymerizable group containing an ethylenically unsaturated double bond and a polymerizable liquid crystal composition containing a photopolymerization initiator. Process and
A semi-curing step of curing the liquid crystal composition layer to form a semi-curing layer satisfying the formulas (1) and (2) described later, and
The polarizer and the semi-cured layer are bonded together using an ultraviolet curable adhesive to prepare a laminate in which the polarizer, the ultraviolet curable adhesive, the semi-cured layer, and the base material are laminated in this order. The bonding process and
A method for producing a polarizing plate, comprising a main curing step of curing a laminate to produce a polarizing plate having a polarizing element and an optically anisotropic layer obtained by further curing the semi-cured layer.

[2] The method for producing a polarizing plate according to [1], which comprises a peeling step of peeling the base material from the laminate after the main curing step.

[3] A method for producing an optical film having a base material and a semi-cured layer.
A liquid crystal composition layer composed of a polymerizable liquid crystal composition containing a liquid crystal compound having a polymerizable group, a hydroxyacetophenone-based photopolymerization initiator, and an oxime ester-based photopolymerization initiator is formed on a substrate. Layer formation process and
A method for producing an optical film, which comprises a semi-curing step of curing a liquid crystal composition layer to form a semi-curing layer satisfying the formulas (1) and (2) described later.

[4] A method for producing an optical film having a base material and a semi-cured layer.
The substrate has a liquid crystal compound having a polymerizable group, a photopolymerization initiator, a repeating unit A represented by the formula (A) described later, and a repeating unit B represented by the formula (B) described later. A layer forming step of forming a liquid crystal composition layer composed of a polymerizable liquid crystal composition containing a copolymer, and a layer forming step.
A method for producing an optical film, which comprises a semi-curing step of curing a liquid crystal composition layer to form a semi-curing layer satisfying the formulas (1) and (2) described later.

[5] The polymerizable liquid crystal composition shows a nematic phase and a smectic phase in this order on the low temperature side of the isotropic phase, and the semi-cured layer is a layer in which the polymerizable liquid crystal composition is immobilized by the smectic phase [3]. ] Or [4], the method for producing an optical film.

[6] A polymerizable liquid crystal composition containing a liquid crystal compound having a polymerizable group, a hydroxyacetophenone-based photopolymerization initiator, and an oxime ester-based photopolymerization initiator.

[7] A co-weight having a liquid crystal compound having a polymerizable group, a photopolymerization initiator, a repeating unit A represented by the formula (A) described later, and a repeating unit B represented by the formula (B) described later. A polymerizable liquid crystal composition containing a coalescence.

According to the present invention, a method for producing a polarizing plate, which has good adhesion between a polarizing element and an optically anisotropic layer and is excellent in optical stability when applied to an image display device, and a method for producing an optical film and polymerization. An anisotropic liquid crystal composition can be provided.

Hereinafter, the present invention will be described in detail.
The description of the constituent elements described below may be based on a typical embodiment of the present invention, but the present invention is not limited to such an embodiment.
In the present specification, the numerical range represented by using "~" means a range including the numerical values before and after "~" as the lower limit value and the upper limit value.
Further, in the present specification, parallel and orthogonal do not mean parallel and orthogonal in a strict sense, but mean a range of ± 5 ° from parallel or orthogonal, respectively.
Further, in the present specification, "(meth) acrylate" is a notation that means either acrylate or methacrylate, and "(meth) acrylic" is a notation that means either acrylic or methacrylic. "(Meta) acryloyl" is a notation that means either acryloyl or methacryloyl.
Further, in the present specification, the liquid crystal composition and the liquid crystal compound include those which no longer exhibit liquid crystal property due to curing or the like as a concept.

《Letteration》
In the present invention, Re (λ) and Rth (λ) represent in-plane retardation at wavelength λ and retardation in the thickness direction, respectively. Unless otherwise specified, the wavelength λ is 550 nm.
In the present invention, Re (λ) and Rth (λ) are values measured at a wavelength λ in AxoScan OPMF-1 (manufactured by Optoscience). By inputting the average refractive index ((Nx + Ny + Nz) / 3) and film thickness (d (μm)) in AxoScan,
Slow phase axial direction (°)
Re (λ) = R0 (λ)
Rth (λ) = ((Nx + Ny) /2-Nz) × d is calculated.

[Manufacturing method of polarizing plate]
The method for producing a polarizing plate of the present invention is a liquid crystal composition comprising a liquid crystal compound having a polymerizable group containing an ethylenically unsaturated double bond and a polymerizable liquid crystal composition containing a photopolymerization initiator on a substrate. The layer forming process for forming the material layer and
A semi-curing step of curing the liquid crystal composition layer to form a semi-curing layer satisfying the following formulas (1) and (2).
The polarizer and the semi-cured layer are bonded together using an ultraviolet curable adhesive to prepare a laminate in which the polarizer, the ultraviolet curable adhesive, the semi-cured layer, and the base material are laminated in this order. The bonding process and
It has a main curing step of curing a laminate to produce a polarizing plate having a polarizing element and an optically anisotropic layer obtained by further curing the semi-cured layer.
1.5 ≤ Sa / Sb ≤ 5.0 Equation (1)
0.03 ≦ (P1-P2) / P3 ≦ 0.2 Equation (2)
In the above formula (1), Sa is obtained by Br-staining the ethylenically unsaturated double bond contained in the semi-cured layer, and then from the surface of the semi-cured layer opposite to the base material, the thickness of the semi-cured layer is 1. It represents the integrated value of the secondary ion intensity derived from Br ions detected by the time-of-flight secondary ion mass spectrometry in the region up to a distance of / 4.
In the above formula (1), Sb is 3/4 of the thickness of the semi-cured layer from the surface of the semi-cured layer on the substrate side after Br-staining the ethylenically unsaturated double bond contained in the semi-cured layer. It represents the integrated value of the secondary ion intensity derived from Br ion detected by the time-of-flight secondary ion mass spectrometry in the region up to the distance of.
In the above formula (2), P1 represents the absorbance at the absorption maximum peak in the ^{wave number range of 820 to 800 cm -1} in the infrared absorption spectrum, and P2 represents the minimum absorbance in the ^{wave number 840 to 800 cm -1 range.} , P3 represent the absorbance at the absorption maximum peak in the wave number range of 1800 to 1650 cm ^-1.

The curing profiles represented by the above formulas (1) and (2) will be described in detail.
First, the above formula (1) is an index showing that the residual amount of ethylenically unsaturated double bonds is distributed in the thickness direction. Although it is not included in the above formula (1), when Sa / Sb is 1.0, it indicates that the curing proceeds uniformly in the thickness direction.
Next, the above formula (2) is an index showing the amount of ethylenically unsaturated double bonds remaining in the entire layer, and is a regulation indicating that the entire layer is cured to some extent. Specifically, P1 in the above formula (2) represents the absorbance at the absorption maximum peak derived from the remaining ethylenically unsaturated double bond, P2 represents the minimum absorbance as a baseline, and P3 represents. It represents the absorbance at the maximum absorption peak derived from the acetyl group for normalizing the difference in absorbance between P1 and P2.

Here, Sa and Sb in the above formula (1) can be measured by the time-of-flight secondary ion mass spectrometry (TOF-SIMS) as described above. Specifically, it can be measured by TOF-SIMS under the measurement conditions shown below.
<Measurement conditions for TOF-SIMS>
The measurement by TOF-SIMS in the present invention is performed as shown below.
(1) The semi-cured layer of the liquid crystal composition layer to be measured was diagonally cut in the thickness direction with an ultramicrotome to expose the cross section. Then, the diagonally cut sample is Br-stained. In addition, Br staining is carried out by gas-phase modifying the sample with 0.3% bromine water in order to add Br to the double bond.
(2) After Br staining, the exposed cross section is measured with the following equipment and conditions.
-Device: TOF-SIMS 4 (manufactured by ION-TOF)
-Primary ion: Bi ^{3 +} primary ion gun (25 kV, 0.2 pA)
・ Charge correction: Combined use of 20 eV low-speed electron gun ・ Measurement area: 300 mm x 300 mm
-Raster: 256 x 256 pixels
・ Cumulative number: 16 times

In the present invention, as described above, a semi-cured layer satisfying the curing profiles represented by the above formulas (1) and (2) is used for bonding with the polarizer, and after bonding, the semi-cured layer is cured again to form an optically anisotropic layer. As a result, the adhesion between the polarizer and the optically anisotropic layer is improved, and a polarizing plate having excellent optical stability can be manufactured when applied to an image display device.
This is not clear in detail, but the present inventors speculate as follows.
That is, when the present inventors use a semi-cured layer satisfying the curing profiles represented by the above formulas (1) and (2), the ultraviolet curable adhesive used for bonding with the polarizer is the basis of the semi-cured layer. Appropriately penetrates into the region from the surface opposite to the material to 1/4 of the film thickness of the semi-cured layer, and 3/4 of the film thickness of the semi-cured layer from the surface of the semi-cured layer on the substrate side. Since it is difficult to penetrate into the region up to the distance of, it is presumed that both the adhesion with the polarizer and the optical stability when applied to the image display device can be achieved.
Hereinafter, each step of the method for manufacturing a polarizing plate of the present invention, members used in each step, and the like will be described in detail.

[Layer formation process]
The layer forming step of the method for producing a polarizing plate of the present invention is a polymerizable liquid crystal composition containing a liquid crystal compound having a polymerizable group containing an ethylenically unsaturated double bond and a photopolymerization initiator on a substrate. (Hereinafter, also abbreviated as “specific polymerizable liquid crystal composition”), which is a step of forming a liquid crystal composition layer.

<Base material>
The base material is not particularly limited as long as it is a base material for supporting the liquid crystal composition layer made of the specific polymerizable liquid crystal composition.

Such a substrate preferably has a film thickness of 5 to 100 μm, more preferably 10 to 75 μm, and even more preferably 15 to 55 μm.
When the film thickness is 5 μm or more, sufficient mechanical strength can be easily secured and failures such as curl, wrinkles, and buckling are unlikely to occur, which is preferable.
Further, when the film thickness is 100 μm or less, the surface pressure applied to the double glazing film is within an appropriate range when the double glazing film of the base material and the semi-cured layer described later is stored in a long roll form, for example. It is preferable because it is easy to adjust to and the adhesion failure is unlikely to occur.

The surface energy of the base material is not particularly limited, but the liquid crystal composition is adjusted by adjusting the relationship between the surface energy of the specific polymerizable liquid crystal composition and the surface energy of the side on which the liquid crystal composition layer of the base material is provided. The adhesive force between the material layer and the base material can be adjusted.
If the surface energy difference is small, the adhesive force tends to increase, and if the surface energy difference is large, the adhesive force tends to decrease, which can be appropriately set.

The surface unevenness of the base material is not particularly limited, but the surface energy, hardness, and surface unevenness of the semi-cured layer, which will be described later, and the surface energy of the surface of the base material opposite to the side on which the liquid crystal composition layer is provided. Depending on the relationship with hardness, for example, it can be adjusted for the purpose of preventing adhesion failure when the multi-layer film of the base material and the semi-cured layer described later is stored in the form of a long roll.
Increasing the surface unevenness tends to suppress adhesion failure, and decreasing the surface unevenness tends to reduce the surface unevenness of the functional film and reduce the haze of the functional film. can. Further, in order to prevent adhesion failure in the roll form and impart transportability of the base material, a protective film may be provided on the side opposite to the side on which the liquid crystal composition layer of the base material is provided.

As such a base material, a known material or film can be appropriately used.
Specific examples of the material include polyester-based polymers, olefin-based polymers, cycloolefin-based polymers, (meth) acrylic-based polymers, cellulosic-based polymers, and polyamide-based polymers.
In particular, polyester-based polymers and olefin-based polymers are preferable as the material of the base film, polyester-based polymers are more preferable, and polyethylene terephthalate (PET) is particularly preferable among polyester-based polymers.
Further, for the purpose of adjusting the surface property of the base material, surface treatment can be appropriately performed. For example, corona treatment, room temperature plasma treatment, saponification treatment and the like can be performed to reduce the surface energy, and silicone treatment, fluorine treatment, olefin treatment and the like can be performed to increase the surface energy.

Further, in order to control the adhesiveness with the semi-cured layer described later, a mold release agent or the like may be appropriately applied to the surface of the base material in advance. The semi-cured layer, which will be described later, can be used by peeling off the base material after bonding with a polarizer. In addition, in a state where the semi-cured layer described later is laminated on the base material, the optical characteristics and mechanical characteristics can be adjusted by appropriately stretching the base material together with the base film.

<Liquid crystal composition layer>
The liquid crystal composition layer is a layer made of a specific polymerizable liquid crystal composition.

(Liquid crystal compound)
The liquid crystal compound contained in the specific polymerizable liquid crystal composition is a liquid crystal compound having a polymerizable group containing an ethylenically unsaturated double bond.
Specific examples of such a polymerizable group include a (meth) acryloyl group, a vinyl group, a styryl group, an allyl group, and the like, and among them, a (meth) acryloyl group is preferable.

The liquid crystal compound is preferably a rod-shaped liquid crystal compound or a discotic liquid crystal compound, and is preferably a rod-shaped liquid crystal compound because the display performance is improved when the obtained polarizing plate is used in an image display device. More preferred.
Examples of the rod-shaped liquid crystal compound include those described in paragraphs [0045] to [0066] of JP-A-2009-217256, and these contents are incorporated in the present specification.
Examples of the discotic liquid crystal compound include paragraphs [0025] to [0153] of JP-A-2006-301614, paragraphs [0020]-[0122] of JP-A-2007-108732, and JP-A-2010-. Examples include those described in paragraphs [0012] to [0108] of Gazette 244038, the contents of which are incorporated herein by reference.

The liquid crystal compound is preferably immobilized in a vertically oriented state from the viewpoint of adjusting the optical characteristics of the optically anisotropic layer described later.
For example, a layer in which a rod-shaped liquid crystal compound is immobilized in a vertically oriented state can function as a positive C-plate. In addition, the layer in which the discotic liquid crystal compound is immobilized in a vertically oriented state can function as a negative A-plate.
In the present invention, the vertical orientation means an orientation state in which the normal direction of the layer and the long axis direction (director) of the liquid crystal molecule are parallel in the case of a rod-shaped liquid crystal compound, and the disctic liquid crystal compound is used. If there is, it means an orientation state in which the normal direction of the layer and the disk surface of the liquid crystal molecules are parallel. The normal direction of the layer and the long axis direction of the liquid crystal molecules or the disk surface of the liquid crystal molecules may be in the range of ± 5 ° from parallel, more preferably within ± 3 °, and ± 2 °. It is more preferably within ± 1 °, and most preferably within ± 1 °.

In the present invention, the specific polymerizable liquid crystal composition preferably exhibits a smectic phase because it can achieve both adhesion to a polarizer and optical stability when applied to an image display device at a higher level. , It is more preferable to show the nematic phase and the smectic phase in this order on the low temperature side of the isotropic phase. The semi-cured layer described later is preferably a layer in which the specific polymerizable liquid crystal composition is immobilized with a smectic phase.

(Photopolymerization initiator)
Examples of the photopolymerization initiator contained in the specific polymerizable liquid crystal composition include "Latest UV Curing Technology" {Technical Information Association, Inc.} (1991), p. 159 and "Ultraviolet Curing System" by Kiyomi Kato (published by General Technology Center in 1989), p. Examples are described in 65-148. In addition, α-carbonyl compounds (described in US Pat. Nos. 2,376,661 and 236,670), acidoin ethers (described in US Pat. No. 2,448,828), α-hydrocarbon-substituted aromatic acidoine compounds (US Pat. No. 2722512 (described in US Pat. No. 2,026,127), polynuclear quinone compound (described in US Pat. , Aclysine and phenazine compounds (Japanese Patent Laid-Open No. 60-105667, US Pat. No. 4,239,850), oxadiazole compounds (US Pat. 40799, Japanese Patent Application Laid-Open No. 5-29234, Japanese Patent Application Laid-Open No. 10-95788, Japanese Patent Application Laid-Open No. 10-29997) and the like.

Commercially available photo-cracking photoradical polymerization initiators include "Irgacure 651", "Irgacure 184", "Irgacure 819", "Irgacure 907" manufactured by BASF Inc. (formerly Ciba Specialty Chemicals Co., Ltd.). "Irgacure 1870", "Irgacure 500", "Irgacure 369", "Irgacure 1173", "Irgacure 2959", "Irgacure 4265", "Irgacure 4263", "Irgacure 127", "Irgacure OXE01", "Irgacure OXE02", etc. , "Kayacure DETX-S", "Kayacure BP-100", "Kayacure BDMM", "Kayacure CTX", "Kayacure BMS", "Kayacure 2-EAQ", "Kayacure ABQ", manufactured by Nippon Kayaku Co., Ltd. "Kayacure CPTX", "Kayacure EPD", "Kayacure ITX", "Kayacure QTX", "Kayacure BTC", "Kayacure MCA", etc. KT37, KIP150, TZT) ”and the like.

In the present invention, the hydroxyacetphenone-based light as a photopolymerization initiator is used because it facilitates the formation of a semi-cured layer satisfying the curing profiles represented by the formulas (1) and (2) described later in the semi-curing step described later. It is preferable to use the polymerization initiator and the oxime ester-based photopolymerization initiator in combination.
Specific examples of the hydroxyacetophenone-based photopolymerization initiator include 1-hydroxy-cyclohexylphenyl ketone and 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-. Propane-1-one, 2-hydroxy-1-{4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propane-1-one, 2-hydroxy-2 -Methyl-1-phenylpropan-1-one and the like can be mentioned.
Specific examples of the oxime ester-based photopolymerization initiator include 1.2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], etanone, 1- [9. -Ethyl-6- (2-methylbenzoyl) -9H-carbazole-3-yl]-, 1- (O-acetyloxime) and the like can be mentioned.

(Copolymer)
The specific polymerizable liquid crystal composition is represented by the following formula (A) because it is easy to form a semi-cured layer satisfying the curing profiles represented by the formulas (1) and (2) described later in the semi-curing step described later. It is preferable to contain a copolymer having a repeating unit A and a repeating unit B represented by the following formula (B).
The reason why the formation of the semi-cured layer becomes easy is not clear in detail, but the present inventors have a base material of the liquid crystal composition layer by having the repeating unit A represented by the following formula (A). Since the copolymer is unevenly distributed on the surface (air interface) on the opposite side of the liquid crystal composition layer and has the repeating unit B represented by the following formula (B), the base material of the liquid crystal composition layer is on the opposite surface. It is presumed that this is because the polymerization rate of the above can be controlled.

In the above formula (A), R ¹ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and L ¹ is −O−, − (C = O) O−, −O (C = O) −. Represents a divalent linking group composed of at least one selected from the group consisting of a divalent aliphatic chain group and a divalent aliphatic cyclic group, where R ² is at least one hydrogen atom. Represents an alkyl group having 1 to 20 carbon atoms substituted with a fluorine atom, or a group containing −Si ( ^Ra21 ) ( ^Ra22 ) O−. R ^a21 and R ^a22 each independently represent an alkyl group having 1 to 12 carbon atoms which may have a substituent.
In the above formula (B), R ³ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and L ² is −O−, − (C = O) O−, −O (C = O) −. a divalent aliphatic chain group, and a divalent least one 2 configured from divalent linking group selected from the group consisting of aliphatic cyclic group, R ⁴ is represented by the following formula (B- Represents a group represented by 1) or (B-2). * Represents the bonding position with ^{L 2.}

^{R 1} in the above formula (A) ^{and R 3} in the above formula (B) independently represent a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, but are a hydrogen atom or an alkyl having 1 to 10 carbon atoms. A group is preferable, a hydrogen atom or an alkyl group having 1 to 4 carbon atoms is more preferable, and a hydrogen atom or a methyl group is further preferable.

^{L 1} in the above formula (A) ^{and L 2} in the above formula (B) are independently of −O−, − (C = O) O−, −O (C = O) − and divalent, respectively. Represents a divalent linking group composed of at least one selected from the group consisting of an aliphatic chain group and a divalent aliphatic cyclic group. Note that-(C = O) O- indicates that ^{the carbon atom on the R 1} (or R ³ ) side and C = O are bonded, and R ² (or R ⁴ ) and O are bonded, and -O (or R 4). C = O) ^{-means that the carbon atom on the R 1} (or R ³ ) side and O are bonded, and R ² (or R ⁴ ) and C = O are bonded.
As the ^{divalent aliphatic chain group represented by L 1} or L ² , an alkylene group having 1 to 20 carbon atoms is preferable, and an alkylene group having 1 to 10 carbon atoms is more preferable.
As the ^{divalent aliphatic cyclic group represented by L 1} or L ^2, a cycloalkylene group having 3 to 20 carbon atoms is preferable, and a cycloalkylene group having 3 to 15 carbon atoms is more preferable.
As L ¹ or L ² , − (C = O) O− or −O (C = O) − is preferable, and − (C = O) O− is more preferable.

In the above formula (A), the alkyl group having 1 to 20 carbon atoms (fluoroalkyl group) in which at least one hydrogen atom is substituted with a fluorine atom represented ^{by R 2 is a fluoroalkyl group having 1 to 18 carbon atoms.} It is preferably a fluoroalkyl group having 2 to 15 carbon atoms, and more preferably. The number of fluorine atoms in the fluoroalkyl group is preferably 1 to 25, more preferably 3 to 21, and most preferably 5 to 21.
Further, in the above formula (A), represented by ^{R 2,} examples of the group include -Si (R ^a21) O-a ^(R a22), include repeating units containing a siloxane bond (polysiloxane structure).

In the present invention, from the viewpoint of obtaining raw materials, the repeating unit A represented by the above formula (A) is preferably the repeating unit represented by the following formula (A1).

In the above formula (A1), R ¹⁰ represents a hydrogen atom or a methyl group, and X represents a hydrogen atom or a fluorine atom. m and n each independently represent an integer of 1 to 20, and m + n represents an integer of 4 to 20.

Specific examples of the monomer constituting such a repeating unit A include 2- (perfluorobutyl) ethyl (meth) acrylate, 2- (perfluorohexyl) ethyl (meth) acrylate, 1H, 1H, and the like. Examples thereof include 7H-dodecafluoroheptyl methacrylate and 4- (perfluoropentyloxy) benzyl acrylate.

Specific examples of the above-mentioned copolymer include the following copolymers.

The weight average molecular weight (Mw) of the copolymer is preferably 1000 to 500,000, more preferably 2000 to 50,000.
Here, the weight average molecular weight of the copolymer is defined as a polystyrene-equivalent value measured by GPC (gel permeation chromatography). For the weight average molecular weight of the polymer compound, for example, EcoSEC HLC-8320GPC (manufactured by Tosoh) was used as the GPC apparatus, three TSKgel SuperAWM-H (manufactured by Tosoh) were used as the columns, and NMP (N-methylpyrrolidone) was used as the eluent. ), The flow rate is 0.50 ml / min, and the temperature is 40 ° C., and the measurement can be performed as a polystyrene-equivalent value.

The content of the specific polymerizable liquid crystal composition when the copolymer is contained is because the adhesion to the polarizer and the optical stability when applied to an image display device can be compatible at a higher level. It is preferably 0.1 to 5.0 parts by mass with respect to the total solid content of the specific polymerizable liquid crystal composition.

(Adhesion improver)
The specific polymerizable liquid crystal composition preferably contains an adhesion improver represented by the following formula (I) for the reason that the adhesion to the polarizer is improved.
Equations (I) (Z) _n − L ¹⁰⁰ − (Q) _m
Here, in the formula (I), Z represents a substituent having a polymerizable group, n represents an integer of 0 to 4, and when n is an integer of 2 to 4, 2 or more Z represents. They may be the same or different.
Further, Q represents a substituent containing at least one boron atom, m represents 1 or 2, and when m is 2, the two Qs may be the same or different.
Further, L ¹⁰⁰ represents a linking group having an n + m valence. However, when n represents 0 and m represents 1, L ¹⁰⁰ is a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, or a substituent. Alternatively, it represents an unsubstituted aryl group or a substituted or unsubstituted heteroaryl group.

In the above formula (I), examples of the substituent having a polymerizable group represented by Z include (meth) acrylate group, styryl group, vinyl ketone group, butadiene group, vinyl ether group, oxylanyl group, aziridinyl group and oxetane group. Examples include substituents.
Of these, a substituent containing a (meth) acrylate group, a styryl group, an oxylanyl group or an oxetane group is preferable, and a substituent containing a (meth) acrylate group or a styryl group is more preferable.

In particular, the substituent containing the (meth) acrylate group is preferably a group having an ethylenically unsaturated double bond represented by the following general formula (V).

In the above general formula (V), R ³ is a hydrogen atom or a methyl group, and a hydrogen atom is preferable.
Further, in the above general formula (V), L ¹ is a single bond, or -O-, -CO-, -NH-, -CO-NH-, -COO-, -O-COO-, an alkylene group. It is a divalent linking group selected from the group consisting of an arylene group, a heterocyclic group, and a combination thereof, preferably a single bond, -CO-NH- or -COO-, and a single bond or -CO-NH- is preferable. Especially preferable.

In the above formula (I), n represents an integer of 0 to 4, preferably 0 or 1, and more preferably 1.
Further, m represents 1 or 2, and preferably represents 1.
Further, as L ¹⁰⁰ , for example, as a divalent linking group, a single bond or -O-, -CO-, -NH-, -CO-NH-, -COO-, -O-COO-, alkylene Examples thereof include a divalent linking group selected from a group, an arylene group, a heteroaryl group, and a combination thereof.
Of these, a substituted or unsubstituted arylene group is more preferable.
The alkyl group, alkenyl group, alkynyl group, aryl group and heteroaryl group represented by L ^{100 are synonymous with R 1} and R ² in the following general formula (VI), and the preferred range is also the same.
In addition, examples of the substituents contained in these groups include the substituents described in paragraph [0046] of JP2013-054201A.

In the above formula (I), Q is a substituent containing at least one boron atom, and is preferably a group that can be adsorbed and bonded to the polymer film.
For example, when the polymer film has a hydroxyl group or a carboxyl group on the surface by surface treatment or the like, a group capable of binding to the hydroxyl group or the carboxyl group of the polymer film is preferable.
The "group that can be adsorbed and bonded to the polymer film" means a group that can be chemically adsorbed to the polymer film by interacting with the structure of the material constituting the polymer film.

Examples of the substituent containing at least one boron atom include a substituent represented by the following general formula (VI).

In the above general formula (VI), R ¹ and R ² are independently hydrogen atoms, substituted or unsubstituted aliphatic hydrocarbon groups, substituted or unsubstituted aryl groups, or substituted or unsubstituted heteroaryl groups, respectively. Represents.
Further, R ¹ and R ² in the general formula (VI), the alkylene groups R ¹ and R ² are linked, an aryl group or may form a linking group comprising a combination thereof.

In the above general formula (VI), the ^{substituted or unsubstituted aliphatic hydrocarbon group represented by R 1} and R ² , respectively, includes a substituted or unsubstituted alkyl group, an alkenyl group and an alkynyl group.
Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group and a hexadecyl group. Octadecyl group, eicosyl group, isopropyl group, isobutyl group, sec-butyl group, tert-butyl group, isopentyl group, neopentyl group, 1-methylbutyl group, isohexyl group, 2-methylhexyl group, cyclopentyl group, cyclohexyl group, 1- Examples thereof include linear, branched or cyclic alkyl groups such as an adamantyl group and a 2-norbornyl group.
Specific examples of the alkenyl group include linear and branched groups such as vinyl group, 1-propenyl group, 1-butenyl group, 1-methyl-1-propenyl group, 1-cyclopentenyl group and 1-cyclohexenyl group. , Or a cyclic alkenyl group.
Specific examples of the alkynyl group include an ethynyl group, a 1-propynyl group, a 1-butynyl group, a 1-octynyl group and the like.
Specific examples of the aryl group include those in which one to four benzene rings form a fused ring and those in which a benzene ring and an unsaturated five-membered ring form a fused ring. Specific examples thereof include those in which a fused ring is formed. Examples thereof include a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, an indenyl group, an acenabutenyl group, a fluorenyl group, a pyrenyl group and the like.

Further, in the above general formula (VI), in ^{the example of the substituted or unsubstituted heteroaryl group represented by R 1} and R ² , respectively, one hetero atom selected from the group consisting of a nitrogen atom, an oxygen atom and a sulfur atom is used. A heteroaryl group obtained by removing one hydrogen atom on the heteroaromatic ring containing the above is included.
Specific examples of a heteroaromatic ring containing one or more heteroatoms selected from the group consisting of nitrogen atom, oxygen atom and sulfur atom include pyrrole, furan, thiophene, pyrazole, imidazole, triazole, oxazole, isoxazole and oxazole. , Thiazole, thiazazole, indole, carbazole, benzofuran, dibenzofuran, thianaften, dibenzothiophene, indazole benzimidazole, anthranil, benzisoxazole, benzoxazole, benzothiazole, purine, pyridine, pyridazine, pyrimidine, pyrazine, triazine, quinoline, acrydin, Examples thereof include isoquinolin, phthalazine, quinazoline, quinoxalin, naphthylidine, phenanthrolin, pteridine and the like.

^{R 1} and R ² in the above general formula (VI) are preferably hydrogen atoms.

^{Further, R 1} and R ² in the above general formula (VI) ^{and L 100} in the above formula (I) may be further substituted with one or more substituents, if possible. One or more of these hydrocarbon groups may be substituted with any substituent. Examples of the substituent include monovalent non-metal atomic groups excluding hydrogen.

The molecular weight of the compound represented by the above formula (I) is preferably 120 to 1200, more preferably 180 to 800.

Specific examples of the compound represented by the above formula (I) include the following compounds in addition to the compounds exemplified in the specific examples described in paragraphs [0035] to [0040] of JP-A-2007-219193. These contents are incorporated herein by reference. Of course, the present invention is not limited to these specific examples.

When the specific polymerizable liquid crystal composition contains the adhesion improver represented by the above formula (I), the content is the mass of the above liquid crystal compound (total mass when two or more kinds of liquid crystal compounds are used in combination). It is preferably 0.5% to 7% by mass, more preferably 1 to 5% by mass, and even more preferably 3 to 5% by mass.

(Other additives)
Other additives may be added to the specific polymerizable liquid crystal composition as long as the gist of the present invention is not deviated.
Other additives include, for example, vertical alignment agents. As the vertical alignment agent, it is preferable to use a pyridinium compound or an onium compound, and by containing these compounds, the liquid crystal compound acts as a vertical alignment agent that promotes the vertical orientation at the polymer film interface of the liquid crystal compound, and the liquid crystal compound. It also contributes to improving the adhesion of the interface between the liquid crystal layer and the polymer film in which the orientation state of the compound is fixed. Pyridinium compounds are described in, for example, [0030] to [0052] of JP-A-2007-0938664, and onium compounds are described in, for example, JP-A-2012-208397, [0027] to [0058]. These contents are incorporated herein.
Further, the liquid crystal layer in which the orientation state of the liquid crystal compound is fixed is, if necessary, an air interface side orientation control agent (for example, a copolymer containing a repeating unit having a fluoroaliphatic group) for controlling the orientation on the air interface side. ) May be contained.
Further, the liquid crystal composition may contain a non-liquid crystal polymerizable monomer. As the polymerizable monomer, a compound having a vinyl group, a vinyloxy group, an acryloyl group or a methacryloyl group is preferable. Specifically, a polyfunctional monomer having two or more polymerizable reactive functional groups, for example, an ester of a polyhydric alcohol and (meth) acrylic acid [for example, ethylene glycol di (meth) acrylate, butanediol di (meth)). Acrylate, hexanediol di (meth) acrylate, 1,4-cyclohexanediacrylate, pentaerythritol tetra (meth) acrylate], pentaerythritol tri (meth) acrylate, trimethylolpropanthry (meth) acrylate, trimethylol ethanetri (meth) ) Acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, pentaerythritol hexa (meth) acrylate, 1,2,3-cyclohexanetetramethacrylate, polyurethane poly Acrylate, polyester polyacrylate], the above-mentioned ethylene oxide modified product, vinylbenzene and its derivatives (for example, 1,4-divinylbenzene, 4-vinylbenzoic acid-2-acryloyl ethyl ester, 1,4-divinylcyclohexanone), vinylsulfone. (Eg divinyl sulfone), acrylamide (eg methylenebis acrylamide) and methacrylamide. Two or more kinds of the above-mentioned monomers may be used in combination.

(solvent)
The specific polymerizable liquid crystal composition can contain a solvent.
The solvent can be appropriately selected from the viewpoints that it tends to have a uniform surface shape during coating and drying, that liquid storage stability can be ensured, and that it has an appropriate saturated vapor pressure.

Specific examples of such a solvent include dibutyl ether, dimethoxyethane, diethoxyethane, propylene oxide, 1,4-dioxane, 1,3-dioxolane, 1,3,5-trioxane, tetrahydrofuran, and anisole. , Fenetol, dimethyl carbonate, methyl ethyl carbonate, diethyl carbonate, acetone, methyl ethyl ketone (MEK), diethyl ketone, dipropyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, methylcyclohexanone, ethyl formate, propyl formate, pentyl formate, methyl acetate , Ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, γ-petitolactone, methyl 2-methoxyacetate, methyl 2-ethoxyacetate, ethyl 2-ethoxyacetate, ethyl 2-ethoxypropionate, 2-methoxyethanol, 2 -Propoxyethanol, 2-butoxyethanol, 1,2-diacetoxyacetone, acetylacetone, diacetone alcohol, methyl acetoacetate, ethyl acetoacetate, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butyl alcohol, cyclohexyl alcohol, isobutyl acetate , Methylisobutylketone (MIBK), 2-octanone, 2-pentanone, 2-hexanone, ethylene glycol ethyl ether, ethylene glycol isopropyl ether, ethylene glycol butyl ether, propylene glycol methyl ether, propylene glycol methyl ether acetate (PGMEA), ethylcarbi Examples thereof include toll, butylcarbitol, hexane, heptane, octane, cyclohexane, methylcyclohexane, ethylcyclohexane, benzene, toluene, xylene and the like, and these may be used alone or in combination of two or more. ..
Of these, it is preferable to use at least one of methyl acetate, ethyl acetate, methyl ethyl ketone, acetone, methyl alcohol and ethyl alcohol.

When such a solvent is used, it is preferable to use the solvent so that the solid content concentration of the specific polymerizable liquid crystal composition is in the range of 5 to 80% by mass, and the solid content concentration is in the range of 10 to 75% by mass. It is more preferable to use a solvent so that the concentration of the solid content is in the range of 15 to 70% by mass, and it is further preferable to use the solvent.

<Method of forming liquid crystal composition layer>
The method for forming the liquid crystal composition layer composed of the specific polymerizable liquid crystal composition is not particularly limited. For example, a method of coating the specific polymerizable liquid crystal composition on the above-mentioned base material or a solution of the specific polymerizable liquid crystal composition. Examples thereof include a method of forming a film, and a coating method is particularly preferable.

Examples of the coating method include a dip coating method, an air knife coating method, a curtain coating method, a roller coating method, a wire bar coating method, a gravure coating method, a slide coating method and an extrusion coating method (die coating method) (Japanese Patent Laid-Open No. 2003-164788). (Refer to the specification), known methods such as the micro gravure coating method are used, and among them, the micro gravure coating method and the die coating method are preferable.

In the present invention, two or more liquid crystal composition layers can be laminated. When two or more layers are laminated, the semi-cured layer on the side to be bonded to the polarizer must satisfy the formulas (1) and (2) described later.
When two or more liquid crystal composition layers are laminated, it is possible to provide an easy-adhesion layer between the layers and perform surface treatment such as corona treatment or plasma treatment, if necessary.

[Semi-curing process]
The semi-curing step of the method for producing a polarizing plate of the present invention is a step of curing the liquid crystal composition layer formed in the above layer forming step to form a semi-curing layer satisfying the following formulas (1) and (2). be.
Sa and Sb in the following formula (1) and P1, P2 and P3 in the following formula (2) are as described above.
1.5 ≤ Sa / Sb ≤ 5.0 Equation (1)
0.03 ≦ (P1-P2) / P3 ≦ 0.2 Equation (2)

In the present invention, the semi-curing step is performed by the following formulas (1-1) and (2) for the reason that the adhesion to the polarizer and the optical stability when applied to the image display device can be compatible at a higher level. It is preferable that the step is to form a semi-cured layer satisfying -2).
1.6 ≤ Sa / Sb ≤ 4.0 Equation (1-1)
0.05 ≦ (P1-P2) / P3 ≦ 0.1 Equation (2-1)

In the semi-curing step, it is effective to cure the liquid crystal composition layer by combining irradiation with ultraviolet rays and heat treatment before, at the same time as, or after irradiation.

The heat treatment performed in combination with the irradiation with ultraviolet rays is not particularly limited as long as it does not damage the semi-cured layer, but is preferably 40 to 150 ° C, more preferably 40 to 110 ° C.
The time required for the heat treatment varies depending on the molecular weight of the component used, the interaction with other components, the viscosity, etc., but is preferably 15 seconds to 1 hour, more preferably 20 seconds to 30 minutes, and 30 minutes. More preferably, it is from seconds to 5 minutes.

Irradiation method of ultraviolet rays is not particularly limited, preferably cured by an irradiation amount of 10mJ ^/ cm ² ~1000mJ ^/ cm 2 by an ultraviolet lamp.
In particular, the integrated irradiation amount is preferably ^{100 to 1000 mJ / cm 2} because the adhesion to the polarizer and the optical stability when applied to an image display device can be compatible at a higher level. ..

In the present invention, it is preferable to irradiate ultraviolet rays in an atmosphere having an oxygen concentration of 2000 ppm or more because it is easy to form a semi-cured layer satisfying the curing profiles represented by the above formulas (1) and (2).

[Lasting process]
In the bonding step of the method for producing a polarizing plate of the present invention, a polarizer and a semi-cured layer formed in the semi-curing step are bonded using an ultraviolet curable adhesive, and the polarizer and the ultraviolet curable type are bonded. This is a step of producing a laminated body in which an adhesive, a semi-cured layer, and a base material are laminated in this order.

<Polarizer>
The polarizer is not particularly limited as long as it is a member having a function of converting light into specific linearly polarized light, and conventionally known absorption-type polarizers and reflection-type polarizers can be used.
As the absorption type polarizer, an iodine-based polarizer, a dye-based polarizer using a dichroic dye, a polyene-based polarizer, and the like are used. The iodine-based polarizer and the dye-based polarizer include a coating type polarizing element and a stretching type polarizing element, both of which can be applied. However, polarized light produced by adsorbing iodine or a dichroic dye on polyvinyl alcohol and stretching the polarizing element. Children are preferred.
Further, as a method for obtaining a polarizer by stretching and dyeing a laminated film having a polyvinyl alcohol layer formed on a substrate, Japanese Patent No. 5048120, Japanese Patent No. 5143918, Japanese Patent No. 46910205, and Japanese Patent No. Japanese Patent No. 4751481 and Japanese Patent No. 4751486 can be mentioned, and known techniques for these polarizers can also be preferably used.
As the reflective polarizer, a polarizer in which thin films having different birefringences are laminated, a wire grid type polarizer, a polarizer in which a cholesteric liquid crystal having a selective reflection region and a 1/4 wave plate are combined, and the like are used.
Among them, a polymer containing a polyvinyl alcohol-based resin (-CH _2- CHOH- as a repeating unit. In particular, at least one selected from the group consisting of polyvinyl alcohol and ethylene-vinyl alcohol copolymers, in that the adhesion is more excellent. It is preferable that the polarizer contains one).

In the present invention, the thickness of the polarizer is not particularly limited, but is preferably 1 μm to 50 μm, more preferably 2 μm to 30 μm, and even more preferably 3 μm to 20 μm.

<UV curable adhesive>
Examples of the ultraviolet curable adhesive include a radically polymerizable adhesive containing a radically polymerizable compound, a cationically polymerizable adhesive containing a cationically polymerizable compound, and the like, which are classified according to the mode of curing. When classified by chemical type, acrylic resin-based adhesives, epoxy resin-based adhesives, and the like can be mentioned.

Examples of the radically polymerizable compound include radically polymerizable compounds having an unsaturated double bond such as a (meth) acrylamide group and a vinyl group, and specifically, a monofunctional radically polymerizable compound in the molecule. Examples thereof include a polyfunctional radical polymerizable compound having two or more polymerizable groups, (meth) acrylate having a hydroxyl group, acrylamide, acryloylmorpholine and the like. These compounds may be used alone or in combination of two or more.
Examples of the cationically polymerizable compound include compounds having an epoxy group and an oxetanyl group. The epoxy compound is not particularly limited as long as it has at least two epoxy groups in the molecule, and for example, a compound described in detail in JP-A-2004-245925 can be used.
Further, a radically polymerizable compound and a cationically polymerizable compound can be used in combination.

As such an ultraviolet curable adhesive, known ones can be used, and for example, JP-A-2017-134413, JP-A-2015-40283, JP-A-2015-187744, JP-A-2015- The ultraviolet curable adhesive described in Japanese Patent Application Laid-Open No. 11094 can be used.

The thickness of the ultraviolet curable adhesive at the time of bonding the polarizer and the semi-cured layer is not particularly limited, and is preferably about 0.01 to 30 μm, more preferably 0.01 to 10 μm, and 0. It is more preferably .05 to 5 μm.

In the present invention, when the polarizer and the semi-cured layer are bonded with an ultraviolet curable adhesive, the semi-cured layer is used for the purpose of improving the adhesive strength and the wettability of the adhesive to the surface of the semi-cured layer. A surface treatment (for example, glow discharge treatment, corona discharge treatment, ultraviolet (UV) treatment, etc.) may be applied to the surface to be bonded to the polarizer of the above, or an easy-adhesion layer may be formed. For example, the materials and forming methods of the easy-adhesion layer described in JP-A-2007-127893 and JP-A-2007-127893 can be used.

[Main curing process]
The main curing step of the method for producing a polarizing plate of the present invention includes a polarizing element and an optically anisotropic layer obtained by further curing the semi-cured layer by curing the laminate produced in the bonding step. This is a step of manufacturing a polarizing plate.

In this curing step, it is effective to cure the laminate produced in the above-mentioned bonding step by combining irradiation with ultraviolet rays and heat treatment before, at the same time as, or after irradiation.

The heat treatment performed in combination with the irradiation with ultraviolet rays is not particularly limited as long as it does not damage the semi-cured layer, but is preferably 40 to 150 ° C, more preferably 40 to 110 ° C.
The time required for the heat treatment varies depending on the molecular weight of the component used, the interaction with other components, the viscosity, etc., but is preferably 15 seconds to 1 hour, more preferably 20 seconds to 30 minutes, and 30 minutes. More preferably, it is from seconds to 5 minutes.

Irradiation method of ultraviolet rays is not particularly limited, preferably cured by an irradiation amount of 10mJ ^/ cm ² ~1000mJ ^/ cm 2 by an ultraviolet lamp.
In particular, the integrated irradiation amount is preferably ^{100 to 1000 mJ / cm 2} because the adhesion to the polarizer and the optical stability when applied to an image display device can be compatible at a higher level. ..

[Peeling process]
The method for producing a polarizing plate of the present invention includes a peeling step of peeling a base material from the polarizing plate produced in the main curing step after the main curing step from the viewpoint of reducing the thickness of the produced polarizing plate. You may be doing it.
Any suitable method can be adopted as the method for peeling the base material. For example, a method of transferring the substrate to the release tape can be adopted.

[Method for manufacturing optical film (first aspect)]
The method for producing an optical film (first aspect) of the present invention is a method for producing an optical film having a base material and a semi-cured layer.
The method for producing an optical film of the present invention (first aspect) contains a liquid crystal compound having a polymerizable group, a hydroxyacetophenone-based photopolymerization initiator, and an oxime ester-based photopolymerization initiator on a substrate. A layer forming step of forming a liquid crystal composition layer composed of a polymerizable liquid crystal composition, and a semi-curing step of curing the liquid crystal composition layer to form a semi-cured layer satisfying the above-mentioned formulas (1) and (2). And have.

Here, the layer forming step in the method for producing an optical film (first aspect) of the present invention is a hydroxy as the above-mentioned specific polymerizable liquid crystal composition among the layer forming steps described in the method for producing a polarizing plate of the present invention. This is an embodiment in which an acetophenone-based photopolymerization initiator and an oxime ester-based photopolymerization initiator are used as essential components.
The semi-curing step in the optical film manufacturing method (first aspect) of the present invention is the same as the semi-curing step described in the polarizing plate manufacturing method of the present invention.
That is, the method for producing an optical film of the present invention (first aspect) is one of the preferred embodiments of the layer forming step and the semi-curing step in the method for producing a polarizing plate of the present invention.

[Method for manufacturing optical film (second aspect)]
The method for producing an optical film (second aspect) of the present invention is a method for producing an optical film having a base material and a semi-cured layer.
The method for producing an optical film (second aspect) of the present invention comprises a liquid crystal compound having a polymerizable group on a substrate, a photopolymerization initiator, a repeating unit A represented by the above formula (A), and a repeating unit A. A layer forming step of forming a liquid crystal composition layer composed of a polymerizable liquid crystal composition containing a copolymer having a repeating unit B represented by the above-mentioned formula (B), and curing the liquid crystal composition layer. It has a semi-curing step of forming a semi-curing layer satisfying the above-mentioned formulas (1) and (2).

Here, the layer forming step in the optical film manufacturing method (second aspect) of the present invention is described above as the above-mentioned specific polymerizable liquid crystal composition among the layer forming steps described in the polarizing plate manufacturing method of the present invention. This is an embodiment in which a copolymer having a repeating unit A represented by the above formula (A) and a repeating unit B represented by the above formula (B) is used as an essential component.
Further, the semi-curing step in the optical film manufacturing method (second aspect) of the present invention is the same step as the semi-curing step described in the polarizing plate manufacturing method of the present invention.
That is, the method for producing an optical film of the present invention (second aspect) is one of the preferred embodiments of the layer forming step and the semi-curing step in the method for producing a polarizing plate of the present invention.

In the method for producing an optical film of the present invention, in both the first and second aspects described above, the above-mentioned specific polymerizable liquid crystal composition preferably exhibits a smectic phase, and is nematic on the low temperature side of the isotropic phase. It is more preferable to show the phase and the smectic phase in this order. The semi-cured layer formed by the semi-cured step is preferably a layer in which the above-mentioned specific polymerizable liquid crystal composition is immobilized with a smectic phase.

[Polymerizable liquid crystal composition (first aspect)]
The polymerizable liquid crystal composition (first aspect) of the present invention is a polymerizable liquid crystal composition containing a liquid crystal compound having a polymerizable group, a hydroxyacetophenone-based photopolymerization initiator, and an oxime ester-based photopolymerization initiator. Is.
Here, the polymerizable liquid crystal composition (first aspect) of the present invention is a hydroxyacetphenone-based photopolymerization initiator among the specific polymerizable liquid crystal compositions described in the layer forming step of the method for producing a polarizing plate of the present invention. , An oxime ester-based photopolymerization initiator is used as an essential component.
That is, the polymerizable liquid crystal composition of the present invention (first aspect) is one of the preferred embodiments of the specific polymerizable liquid crystal composition used in the layer forming step in the method for producing a polarizing plate of the present invention.

[Polymerizable liquid crystal composition (second aspect)]
The polymerizable liquid crystal composition (second aspect) of the present invention comprises a liquid crystal compound having a polymerizable group, a photopolymerization initiator, a repeating unit A represented by the above-mentioned formula (A), and the above-mentioned formula (B). ) Is a polymerizable liquid crystal composition containing a copolymer having a repeating unit B represented by).
Here, the polymerizable liquid crystal composition (second aspect) of the present invention is represented by the above-mentioned formula (A) among the specific polymerizable liquid crystal compositions described in the layer forming step of the method for producing a polarizing plate of the present invention. This is an embodiment in which a copolymer having the repeating unit A and the repeating unit B represented by the above-mentioned formula (B) is used as an essential component.
That is, the polymerizable liquid crystal composition of the present invention (second aspect) is one of the preferred embodiments of the specific polymerizable liquid crystal composition used in the layer forming step in the method for producing a polarizing plate of the present invention.

The present invention will be described in more detail below based on examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be appropriately changed as long as they do not deviate from the gist of the present invention. Therefore, the scope of the present invention should not be construed as limiting by the examples shown below.

[Example 1]
[Layer formation process]
As a base material, a cycloleolefin polymer film (Arton film, Re = 125 nm, Rth = 63 nm, film thickness 25 μm, manufactured by JSR Corporation) was used.
One side of the substrate is corona-treated with a discharge amount of 125 W · min / m ² , and the polymerizable liquid crystal composition prepared with the following composition is applied to the corona-treated surface with a # 3.0 wire bar. , A liquid crystal composition layer was formed.

―――――――――――――――――――――――――――――――――
Polymerizable liquid crystal composition ――――――――――――――――――――――――――――――――――
-The following liquid crystal compound L-1 100.0 parts by mass-Hydroxyacetophenone-based photopolymerization initiator (Irgacure127, manufactured by BASF) 5.0 parts by mass-Oxym ester-based photopolymerization initiator (OXE-01, manufactured by BASF) 2.0 parts by mass ・ Monomer (ATMMT, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.) 8.0 parts by mass ・ The following orientation aid A-1 4.5 parts by mass ・ The following orientation aid A-2 2.0 parts by mass ・The following leveling agent B-1 0.3 parts by mass, acetone 438.5 parts by mass, PGMEA 48.7 parts by mass ――――――――――――――――――――――――― ――――――――

-Liquid crystal compound L-1
A mixture of the following liquid crystal compounds (RA) (RB) (RC) at 83: 15: 2 (mass ratio)

・ Orientation aid A-1

・ Orientation aid A-2

-Leveling agent B-1 (weight average molecular weight: 15,000, numerical value in the following formula: mass%)

[Semi-curing process]
After the layer forming step, the composition was heated with warm air at 70 ° C. for 90 seconds for drying of the solvent and orientation aging of the liquid crystal compound.
Next, ultraviolet irradiation (500 mJ / cm ² ) was performed at 40 ° C. in the air atmosphere to fix the orientation of the liquid crystal compound and form a semi-cured layer. The Rth of the semi-cured layer was -100 nm. The curing profiles shown in the above formulas (1) and (2) in the formed semi-cured layer are as shown in Table 1 below.

[Lasting process]
<Preparation of UV curable adhesive>
An ultraviolet curable adhesive having the following composition was prepared.
――――――――――――――――――――――――――――――――――
UV curable adhesive ――――――――――――――――――――――――――――――――――
・ Aronix M-220 (manufactured by Toa Synthetic Co., Ltd.) 20 parts by mass ・ 4-Hydroxybutyl acrylate (manufactured by Nippon Kasei Co., Ltd.) 60 parts by mass ・ -2-ethylhexyl acrylate (manufactured by Mitsubishi Chemical Corporation) 20 parts by mass ・ Irgacure 907 (Manufactured by BASF) 1.5 parts by mass, KAYACURE DETX-S (manufactured by Nippon Kayaku Co., Ltd.) 0.5 parts by mass ―――――――――――――――――――――― ――――――――――――

<Attachment>
The prepared ultraviolet curable adhesive was applied to the surface of the semi-cured layer opposite to the base material (cycloleolefin polymer) so as to have a thickness of 0.5 μm.
Then, the adhesive-coated surface was bonded to the polarizer to prepare a laminate in which the polarizer, the ultraviolet curable adhesive, the semi-cured layer, and the base material were laminated in this order.

[Main curing process]
^{After the above bonding step, ultraviolet rays of 1000 mJ / cm 2 were} irradiated from the base material side of the optical film at 40 ° C. in the atmospheric atmosphere. Then, it dried at 60 degreeC for 3 minutes to prepare the polarizing plate of Example 1.

[Examples 2 to 7 and Comparative Examples 1 to 5]
Polarizing by the same method as in Example 1 except that the composition of the polymerizable liquid crystal composition was changed to the composition shown in Tables 1 to 3 below and the conditions of the semi-curing step were changed to the conditions shown in Tables 1 to 3 below. A plate was made.
In Tables 2 and 3 below, the structures of the polymerization inhibitor C-1 and the like are as shown below.

Polymerization inhibitor C-1 (Mw: 20000)

Polymerization inhibitor C-2 (Mw: 20000)

Liquid crystal compound L-2

Liquid crystal compound L-3

Monomer L-4

[Example 8]
[Preparation of polarizing plate]
The photoalignment film-forming material described in Example 1 of WO 2016/002722 was prepared and coated on an 80 μm TAC film with a bar coater.
After coating, it was dried on a hot plate at 120 ° C. for 1 minute to remove the solvent, and a photoisomerization composition layer having a thickness of 0.3 μm was formed.
The obtained photoisomerization composition layer was irradiated with polarized ultraviolet rays (10 mJ / cm ² , using an ultrahigh pressure mercury lamp) to form a photoalignment film.
The composition of the following first liquid crystal layer was applied on the above photoalignment film with a bar coater to form a composition layer. The formed composition layer was once heated to 110 ° C. on a hot plate and then cooled to 60 ° C. to stabilize the orientation. Then, the temperature was maintained at 60 ° C., ^{and the orientation was fixed by ultraviolet irradiation (500 mJ / cm 2} , using an ultrahigh pressure mercury lamp) under a nitrogen atmosphere (oxygen concentration 100 ppm) to prepare a first optically anisotropic layer having a thickness of 2 μm. ..

―――――――――――――――――――――――――――――――――
Composition of the first liquid crystal layer ――――――――――――――――――――――――――――――――――
・ Cyclopentanone 16.2 parts by mass ・ MEK 51.1 parts by mass ・ Liquid compound L-2 13.2 parts by mass ・ Liquid compound L-3 13.2 parts by mass ・ Liquid compound L-4 5.0 Parts by mass ・ Polyethylene glycol # 200 diacrylate 0.5 parts by mass ・ Oxym ester-based photopolymerization initiator (OXE-01, manufactured by BASF) 0.5 parts by mass ・ The following leveling agent P-1 0.2 parts by mass-- ―――――――――――――――――――――――――――――――

-Leveling agent P-1 (mass ratio a: b: c = 50: 30: 20 in the following formula)

The surface of the first optically anisotropic layer was corona-treated with a discharge amount of 125 W · min / m ^2.
Then, using the polymerizable liquid crystal composition used in Example 7, a layer forming step, a semi-curing step and a bonding step were carried out in the same manner as in Example 7, and a polarizer, an ultraviolet curable adhesive, and semi-curing were performed. A laminate having a layer, a first optically anisotropic layer, and a TAC film in this order was produced.
Next, after performing the main curing step in the same manner as in Example 7, the TAC film was peeled off to prepare a polarizing plate.

[evaluation]
[Adhesion]
Evaluation was performed by the cross-cut method described in JIS-K-5600-5-6-1.
Specifically, 100 grids are placed on the surface of the base material (first optically anisotropic layer in Example 8) of the produced polarizing plate at 1 mm intervals, and the cells are adhered with cellophane tape (manufactured by Nichiban Co., Ltd.). The test was conducted. After applying a new cellophane tape, it was peeled off and judged according to the following criteria. The results are shown in Tables 1 to 3 below.
A: No peeling of squares in the grid B: 50% or more and less than 100% without peeling of squares in the grid C: 20% or more and less than 50% without peeling of squares in the grid D: Less than 20% of the grids have no peeling of squares. It is the standard of A, B, and C that there is no problem in practical use. It is preferably the standard of A.

[Optical stability]
<Manufacturing of liquid crystal display device>
The polarizing plate was peeled off from the liquid crystal cell of iPad (registered trademark, manufactured by Apple Inc.) and used as a liquid crystal cell in IPS mode.
Instead of the peeled polarizing plate, the polarizing plate prepared above was bonded to a liquid crystal cell using SK2057 manufactured by Soken Kagaku Co., Ltd. to prepare a liquid crystal display device.
The prepared liquid crystal display device was exposed to an environment of 65 ° C. and 90% for 500 hours, and the display performance was observed.
Specifically, for each of the manufactured liquid crystal display devices, a measuring device "EZ-Contrast XL88" (manufactured by ELDIM) was used to measure the azimuth from 0 ° (horizontal direction) to 359 ° counterclockwise in 1 ° increments. The brightness (Yw) in the white display and the brightness (Yb) in the black display are measured in 1 ° increments from the polar angle 0 ° (front direction) to 88 °, the contrast ratio (Yw / Yb) is calculated, and the azimuth angle is calculated. The contrast ratio was evaluated in the directions of 45 ° and a polar angle of 60 ° according to the following evaluation criteria. The results are shown in Tables 1 to 3 below.
A: The area with a high contrast ratio is particularly wide and particularly excellent (contrast ratio: 200 or more).
B: The area with high contrast ratio is wide and excellent (contrast ratio: 150 or more and less than 200).
C: The area with high contrast ratio is narrow (contrast ratio: 100 or more and less than 150)
D: The area with high contrast ratio is narrow (contrast ratio: less than 100)

From the results shown in Tables 1 to 3, when a cured layer that does not satisfy the curing profiles represented by the above formulas (1) and (2) is formed, the adhesion between the polarizer and the optically anisotropic layer is inferior. Alternatively, it was found that even if the adhesion between the polarizer and the optically anisotropic layer is good, the optical stability when applied to an image display device is inferior (Comparative Examples 1 to 5).
On the other hand, when the semi-cured layer satisfying the curing profiles shown in the above formulas (1) and (2) was formed, the adhesion between the polarizer and the optically anisotropic layer became good, and the produced polarizing plate was produced. Was found to be good in optical stability when applied to an image display device (Examples 1 to 8).

Claims (6)

A layer forming step of forming a liquid crystal composition layer composed of a liquid crystal compound having a polymerizable group containing an ethylenically unsaturated double bond and a polymerizable liquid crystal composition containing a photopolymerization initiator on a base material,
A semi-curing step of curing the liquid crystal composition layer to form a semi-curing layer satisfying the following formulas (1) and (2).
The polarizer and the semi-cured layer were bonded to each other using an ultraviolet curable adhesive, and the polarizer, the ultraviolet curable adhesive, the semi-cured layer, and the base material were laminated in this order. The bonding process to prepare the laminate and
A method for producing a polarizing plate, comprising a main curing step of curing the laminate to produce a polarizing plate having the polarizing element and an optically anisotropic layer obtained by further curing the semi-cured layer.
1.5 ≤ Sa / Sb ≤ 5.0 Equation (1)
0.03 ≦ (P1-P2) / P3 ≦ 0.2 Equation (2)
In the formula (1), Sa is obtained by Br-staining the ethylenically unsaturated double bond contained in the semi-cured layer, and then from the surface of the semi-cured layer opposite to the substrate, the thickness of the semi-cured layer is increased. It represents the integrated value of the secondary ion intensity derived from Br ions detected by the time-of-flight secondary ion mass spectrometry in the region up to 1/4 of the distance.
In the formula (1), Sb is obtained by Br-staining the ethylenically unsaturated double bond contained in the semi-cured layer, and then from the surface of the semi-cured layer on the substrate side to 3 / of the thickness of the semi-cured layer. It represents the integrated value of the secondary ion intensity derived from Br ions detected by the time-of-flight secondary ion mass spectrometry in the region up to a distance of 4.
In the above formula (2), P1 represents the absorbance at the absorption maximum peak in the range ^{of wave number 820 to 800 cm -1} in the infrared absorption spectrum, and P2 represents the minimum absorbance in the range of ^{wave number 840 to 800 cm -1.} , P3 represent the absorbance at the absorption maximum peak in the wave number range of 1800 to 1650 cm ^-1. The method for producing a polarizing plate according to claim 1, further comprising a peeling step of peeling the base material from the laminate after the main curing step. A method for producing an optical film having a base material and a semi-cured layer.
A liquid crystal composition layer composed of a polymerizable liquid crystal composition containing a liquid crystal compound having a polymerizable group, a hydroxyacetophenone-based photopolymerization initiator, and an oxime ester-based photopolymerization initiator is formed on a substrate. Layer formation process and
A method for producing an optical film, which comprises a semi-curing step of curing the liquid crystal composition layer to form a semi-curing layer satisfying the following formulas (1) and (2).
1.5 ≤ Sa / Sb ≤ 5.0 Equation (1)
0.03 ≦ (P1-P2) / P3 ≦ 0.2 Equation (2)
In the formula (1), Sa is obtained by Br-staining the ethylenically unsaturated double bond contained in the semi-cured layer, and then from the surface of the semi-cured layer opposite to the substrate, the thickness of the semi-cured layer is increased. It represents the integrated value of the secondary ion intensity derived from Br ions detected by the time-of-flight secondary ion mass spectrometry in the region up to 1/4 of the distance.
In the formula (1), Sb is obtained by Br-staining the ethylenically unsaturated double bond contained in the semi-cured layer, and then from the surface of the semi-cured layer on the substrate side to 3 / of the thickness of the semi-cured layer. It represents the integrated value of the secondary ion intensity derived from Br ions detected by the time-of-flight secondary ion mass spectrometry in the region up to a distance of 4.
In the above formula (2), P1 represents the absorbance at the absorption maximum peak in the range ^{of wave number 820 to 800 cm -1} in the infrared absorption spectrum, and P2 represents the minimum absorbance in the range of ^{wave number 840 to 800 cm -1.} , P3 represent the absorbance at the absorption maximum peak in the wave number range of 1800 to 1650 cm ^-1. A method for producing an optical film having a base material and a semi-cured layer.
A copolymer having a liquid crystal compound having a polymerizable group, a photopolymerization initiator, a repeating unit A represented by the following formula (A) and a repeating unit B represented by the following formula (B) on a substrate. A layer forming step of forming a liquid crystal composition layer composed of a polymerizable liquid crystal composition containing a coalescence, and a layer forming step.
A method for producing an optical film, which comprises a semi-curing step of curing the liquid crystal composition layer to form a semi-curing layer satisfying the following formulas (1) and (2).
1.5 ≤ Sa / Sb ≤ 5.0 Equation (1)
0.03 ≦ (P1-P2) / P3 ≦ 0.2 Equation (2)
In the formula (1), Sa is obtained by Br-staining the ethylenically unsaturated double bond contained in the semi-cured layer, and then from the surface of the semi-cured layer opposite to the substrate, the thickness of the semi-cured layer is increased. It represents the integrated value of the secondary ion intensity derived from Br ions detected by the time-of-flight secondary ion mass spectrometry in the region up to 1/4 of the distance.
In the formula (1), Sb is obtained by Br-staining the ethylenically unsaturated double bond contained in the semi-cured layer, and then from the surface of the semi-cured layer on the substrate side to 3 / of the thickness of the semi-cured layer. It represents the integrated value of the secondary ion intensity derived from Br ions detected by the time-of-flight secondary ion mass spectrometry in the region up to a distance of 4.
In the above formula (2), P1 represents the absorbance at the absorption maximum peak in the range ^{of wave number 820 to 800 cm -1} in the infrared absorption spectrum, and P2 represents the minimum absorbance in the range of ^{wave number 840 to 800 cm -1.} , P3 represent the absorbance at the absorption maximum peak in the wave number range of 1800 to 1650 cm ^-1.

In the formula (A), R ¹ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and L ¹ is −O−, − (C = O) O−, −O (C = O) −. Represents a divalent linking group composed of at least one selected from the group consisting of a divalent aliphatic chain group and a divalent aliphatic cyclic group, where R ² is at least one hydrogen atom. Represents an alkyl group having 1 to 20 carbon atoms substituted with a fluorine atom, or a group containing −Si ( ^Ra21 ) ( ^Ra22 ) O−. R ^a21 and R ^a22 each independently represent an alkyl group having 1 to 12 carbon atoms which may have a substituent.
In the formula (B), R ³ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and L ² is −O−, − (C = O) O−, −O (C = O) −. a divalent aliphatic chain group, and a divalent least one 2 configured from divalent linking group selected from the group consisting of aliphatic cyclic group, R ⁴ is represented by the following formula (B- Represents a group represented by 1) or (B-2). * Represents the bonding position with ^{L 2.}

The claim that the polymerizable liquid crystal composition shows a nematic phase and a smectic phase in this order on the low temperature side of the isotropic phase, and the semi-cured layer is a layer in which the polymerizable liquid crystal composition is immobilized by a smectic phase. The method for producing an optical film according to 3 or 4. It contains a liquid crystal compound having a polymerizable group, a photopolymerization initiator, and a copolymer having a repeating unit A represented by the following formula (A) and a repeating unit B represented by the following formula (B). Polymerizable liquid crystal composition.

In the formula (A), R ¹ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and L ¹ is −O−, − (C = O) O−, −O (C = O) −. Represents a divalent linking group composed of at least one selected from the group consisting of a divalent aliphatic chain group and a divalent aliphatic cyclic group, where R ² is at least one hydrogen atom. Represents an alkyl group having 1 to 20 carbon atoms substituted with a fluorine atom, or a group containing −Si ( ^Ra21 ) ( ^Ra22 ) O−. R ^a21 and R ^a22 each independently represent an alkyl group having 1 to 12 carbon atoms which may have a substituent.
In the formula (B), R ³ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and L ² is −O−, − (C = O) O−, −O (C = O) −. a divalent aliphatic chain group, and a divalent least one 2 configured from divalent linking group selected from the group consisting of aliphatic cyclic group, R ⁴ is represented by the following formula (B- Represents a group represented by 1) or (B-2). * Represents the bonding position with ^{L 2.}