JP2015187717A - Method for manufacturing circularly polarizing plate - Google Patents

Abstract

A method for producing a circularly polarizing plate by transferring a λ / 4 plate having an optically anisotropic layer containing a liquid crystal compound is provided. A method of manufacturing a circularly polarizing plate having an optical laminate and a polarizing film, wherein an alignment film is formed on the transparent support without subjecting the transparent support to saponification, and a liquid crystal is formed on the alignment film. A step of producing a laminate A by forming an optically anisotropic layer containing a compound, a step of preparing a polarizing plate having a polarizing film protective film on at least one surface of the polarizing film, and a polarizing plate A circularly polarizing plate having a step of producing a circularly polarizing plate having an optical laminated body and a polarizing film by laminating the surface on the optically anisotropic layer side of the laminated body A and peeling the transparent support from the laminated body A Manufacturing method. [Selection figure] None

Description

  The present invention relates to a method for producing a circularly polarizing plate.

Conventionally, circularly polarizing plates have been used in organic EL display devices, LCD display devices, and the like in order to suppress adverse effects due to external light reflection.
As a circularly-polarizing plate, for example, as described in Patent Document 1, a mode in which a retardation plate including an optically anisotropic layer and a linearly polarizing film (polarizing film) are combined is disclosed. More specifically, as the optically anisotropic layer, a laminate in which an optically anisotropic layer A composed of a discotic liquid crystal compound and an optically anisotropic layer B composed of a rod-like liquid crystal compound are stacked is used. ing. Further, as a method for producing a circularly polarizing plate, a method for producing a circularly polarizing plate by transferring a λ / 4 plate is also described.

JP 2001-155866 A

  Patent Document 1 describes a method of producing a circularly polarizing plate by transferring a λ / 4 plate, but does not describe a specific method. The inventors of the present invention have studied a method for producing a circularly polarizing plate by transferring a λ / 4 plate having an optically anisotropic layer containing a liquid crystal compound. An improvement was needed.

The inventors studied diligently about a method for producing a circularly polarizing plate by transferring a λ / 4 plate having an optically anisotropic layer containing a liquid crystal compound. First, in order to form an optically anisotropic layer, when an alignment film is formed on a transparent support and an optically anisotropic layer is formed on the alignment film, transfer may be successful depending on the object or method to be transferred. Although not possible, a laminate A in which an alignment film and an optically anisotropic layer were formed on a transparent support without producing a saponification treatment on the transparent support was prepared. It has been found that the above-mentioned problems can be solved by attaching the surface to the transfer target and peeling the transparent support from the laminate A.
That is, it has been found that the above object can be achieved by the following configuration.

[1] A method for producing a circularly polarizing plate having an optical laminate and a polarizing film,
Forming a laminated body A by forming an alignment film on the transparent support without forming a saponification treatment on the transparent support, and forming an optically anisotropic layer containing a liquid crystal compound on the alignment film;
A step of preparing a polarizing plate having a polarizing film protective film on at least one surface of the polarizing film, and a surface on the optically anisotropic layer side of the laminate A are bonded to the polarizing plate, and the transparent support is provided from the laminate A. The manufacturing method of the circularly-polarizing plate which has the process of producing the circularly-polarizing plate which has an optical laminated body and a polarizing film by peeling.
[2] The transparent support is a cellulose acylate film,
The optical laminate has a first optical anisotropic layer (H) and a second optical anisotropic layer (Q),
At least one of the first optical anisotropic layer (H) and the second optical anisotropic layer (Q) is an optical anisotropic layer formed from a composition containing a liquid crystal compound,
ReH (550) and ReQ (550) which are in-plane retardation values of the first optically anisotropic layer (H) and the second optically anisotropic layer (Q) measured at a wavelength of 550 nm are expressed by the following formula (1). The manufacturing method of the circularly-polarizing plate as described in [1] which satisfies the relationship of-(2).
Formula (1) ReH (550) = 2 × ReQ (550) ± 50
Formula (2) 100 ≦ ReQ (550) ≦ 180
[3] The first optically anisotropic layer (H) and the second optically anisotropic layer (Q) are both optically anisotropic layers formed from a composition containing a liquid crystal compound,
At least one of the first optically anisotropic layer (H) and the second optically anisotropic layer (Q) bonds the optically anisotropic layer side surface of the laminate A to the polarizing plate, and the laminate A The manufacturing method of the circularly-polarizing plate as described in [2] produced by peeling a transparent support body more.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of (lambda) / 4 board which has an optically anisotropic layer containing the liquid crystal compound by transcription | transfer can be provided.

It is a schematic sectional drawing of the 1st embodiment of the circularly-polarizing plate of this invention. It is a schematic sectional drawing of the 2nd embodiment of the circularly-polarizing plate of this invention.

<Optical laminate>
The optical laminate is preferably a λ / 4 plate. Here, the λ / 4 plate (plate having a λ / 4 function) is a plate having a function of converting linearly polarized light having a specific wavelength into circularly polarized light (or circularly polarized light into linearly polarized light). More specifically, the plate has an in-plane retardation value of λ / 4 (or an odd multiple thereof) at a predetermined wavelength λnm. The in-plane retardation value (Re (550)) at a wavelength of 550 nm of the λ / 4 plate may have an error of about 25 nm around the ideal value (137.5 nm), for example, 110 to 160 nm. Is more preferable, 120 to 150 nm is more preferable, and 130 to 145 nm is still more preferable.
The λ / 4 plate may have a single layer structure or a multilayer structure, and examples of the multilayer structure include a broadband λ / 4 plate formed by laminating a λ / 4 plate and a λ / 2 plate. In the present invention, a broadband λ / 4 plate formed by laminating a λ / 4 plate and a λ / 2 plate is preferable. As for the broadband λ / 4 plate (λ / 4 plate and λ / 2 plate), the descriptions in paragraphs [0030] to [0033] of International Publication No. 2013/137464) are appropriately adopted without departing from the present invention. be able to.

As a preferred embodiment of the optical laminate, the optical laminate has a first optical anisotropic layer (H) and a second optical anisotropic layer (Q), and the first optical anisotropic layer (H) and the first optical anisotropic layer (H) At least one of the two optically anisotropic layers (Q) is an optically anisotropic layer formed from a composition containing a liquid crystal compound, and the first optically anisotropic layer (H) and the first optically anisotropic layer measured at a wavelength of 550 nm. It is preferable that ReH (550) and ReQ (550), which are in-plane retardation values of the two optically anisotropic layers (Q), satisfy the following formulas (1) to (2).
Formula (1) ReH (550) = 2 × ReQ (550) ± 50
Formula (2) 100 ≦ ReQ (550) ≦ 180
More preferably, the first optically anisotropic layer (H) and the second optically anisotropic layer (Q) are both optically anisotropic layers formed from a composition containing a liquid crystal compound. And at least one of the first optically anisotropic layer (H) and the second optically anisotropic layer (Q) bonds the optically anisotropic layer side surface of the laminate A to the polarizing plate, and the laminate It is preferable that the transparent support is peeled off from A.

<Method for producing circularly polarizing plate>
The circularly polarizing plate can be produced by the following steps (1) to (6). In addition, regarding the process of producing the laminated body A, the conditions of the following processes (1) to (3) are described in, for example, paragraphs [0131] to [0133] of Patent Document 1 (International Publication No. 2014/073616). Each process in the manufacturing method of the produced phase difference plate can be employ | adopted suitably.
Step (1): An alignment film is provided on the transparent support without subjecting the transparent support to saponification.
Step (2): A step of applying a liquid crystal composition containing a liquid crystal compound (for example, a discotic liquid crystal compound) on the alignment film, and performing a heat treatment as necessary to align the liquid crystal compound. ): A step of producing a laminate A by applying a curing treatment to the liquid crystalline compound to form an optically anisotropic layer Step (4): A polarizing film protective film is provided on at least one surface of the polarizing film. Step of preparing polarizing plate Step (5): Step of bonding the optically anisotropic layer side of laminate A to the polarizing plate Step (6): Transparent support from laminate A bonded to polarizing plate The process of producing the polarizing plate which has an optical laminated body and a polarizing film by peeling a body

<Transparent support>
The transparent support is a base material used for forming an optically anisotropic layer containing a liquid crystal compound.
As a material for forming the transparent support, a polymer excellent in optical performance transparency, mechanical strength, thermal stability, moisture shielding property, isotropy and the like is preferable. The term “transparent” as used in the present invention indicates that the visible light transmittance is 60% or more, preferably 80% or more, and particularly preferably 90% or more.
As a material for forming the transparent support, a cellulose-based polymer (particularly preferably, cellulose acylate) represented by triacetyl cellulose, which has been conventionally used as a transparent protective film of a polarizing plate, can be preferably used.

<Alignment film>
In the present invention, it is preferable to apply a composition for forming an optically anisotropic layer on the surface of an alignment film to align molecules of a liquid crystal compound (for example, a discotic liquid crystal compound). If the alignment state is fixed after the alignment of the liquid crystalline compound, the alignment film plays its role, so it is not always essential for the circularly polarizing plate finally obtained by the production method of the present invention. Absent.
The alignment film generally contains a polymer as a main component. The polymer material for alignment film is described in many documents, and many commercially available products can be obtained. The polymer material used is preferably polyvinyl alcohol or polyimide, and derivatives thereof. In particular, modified or unmodified polyvinyl alcohol is preferred. Regarding the alignment film that can be used, the modified polyvinyl alcohol described in WO01 / 88574A1, page 43, line 24 to page 49, line 8, and paragraphs [0071] to [0095] of Japanese Patent No. 3907735 can be referred to. . The alignment film is usually subjected to a known rubbing treatment. That is, the alignment film is usually preferably a rubbing alignment film that has been rubbed.
The thickness of the alignment film is preferably 0.01 to 10 μm, more preferably 0.01 to 1 μm, and still more preferably 0.01 to 0.5 μm.

<Optically anisotropic layer and laminate A>
The laminate A is a λ / 4 plate or a λ / 2 plate, and an optically anisotropic layer containing a liquid crystal compound plays a role of a λ / 4 function or a λ / 2 function.
A λ / 4 plate or λ / 2 plate having an optically anisotropic layer containing a liquid crystal compound forms an alignment film on the transparent support and forms an optically anisotropic layer containing the liquid crystal compound on the alignment film. It is known that it can be obtained by doing so. In general, the transparent support is saponified before the step of forming the alignment film on the transparent support. In the present invention, the transparent support is not subjected to saponification treatment. An alignment film is formed on the body.
That is, it is preferable to use a cellulose acylate film (unsaponified cellulose acylate film) that has not been saponified as the transparent support. By using this cellulose acylate film, the peel strength at the interface between the peelable support and the alignment film is further lowered, and the peelable support is more easily separated.

  In order to set the retardation in the optically anisotropic layer to about λ / 4 or λ / 2, the alignment state of the liquid crystal compound may be controlled. At this time, when using a rod-like liquid crystal compound, it is preferable to fix the rod-like liquid crystal compound in a horizontally aligned state. When using a discotic liquid crystal compound, the discotic liquid crystal compound is fixed in a vertically aligned state. It is preferable to do this. Note that “the rod-like liquid crystal compound is horizontally aligned” means that the director of the rod-like liquid crystal compound and the layer surface are parallel, and “the discotic liquid crystal compound is vertically aligned” means that the disc surface and the layer surface of the discotic liquid crystal compound are Say that it is vertical.

(Liquid crystal compound)
In general, liquid crystal compounds can be classified into a rod type and a disk type from the shape. In addition, there are low and high molecular types, respectively. Polymer generally refers to a polymer having a degree of polymerization of 100 or more (Polymer Physics / Phase Transition Dynamics, Masao Doi, 2 pages, Iwanami Shoten, 1992). In the present invention, any liquid crystal compound can be used, but a rod-like liquid crystal compound (hereinafter also abbreviated as “CLC” or “CLC compound”) or a discotic liquid crystal compound (discotic liquid crystal compound) (hereinafter referred to as “CLC”). It is preferable to use “DLC” or “DLC compound”. Two or more kinds of rod-like liquid crystalline compounds, two or more kinds of disc-like liquid crystalline compounds, or a mixture of a rod-like liquid crystalline compound and a disk-like liquid crystalline compound may be used. In order to fix the liquid crystalline compound, it is more preferable to use a rod-like liquid crystalline compound having a polymerizable group or a discotic liquid crystalline compound, and the liquid crystalline compound has 2 polymerizable groups in one molecule. It is more preferable to have the above. In the case where the liquid crystal compound is a mixture of two or more, it is preferable that at least one liquid crystal compound has two or more polymerizable groups in one molecule.

As the rod-like liquid crystalline compound, for example, those described in claim 1 of JP-T-11-53019 and paragraphs [0026] to [0098] of JP-A-2005-289980 can be preferably used. As the tick liquid crystal compound, for example, those described in paragraphs [0020] to [0067] of JP-A-2007-108732 and paragraphs [0013] to [0108] of JP-A-2010-244038 are preferably used. However, it is not limited to these.
The polymerizable group is not particularly limited as long as it is a polymerizable group capable of causing polymerization or crosslinking reaction by actinic rays, electron beams, heat, or the like, and examples thereof include a polymerizable ethylenically unsaturated group or a ring polymerizable group. Specifically, (meth) acryloyloxy group, vinyl group, styryl group, allyl group and the like can be mentioned. Of these, a (meth) acryloyloxy group is preferable. The “(meth) acryloyloxy group” is a description that comprehensively represents an acryloyloxy group or a methacryloyloxy group, and the “(meth) acrylate” described later generally represents an acrylate or methacrylate. It is a description.

  Moreover, in order to make a liquid crystal compound into a horizontal alignment and a vertical alignment state, you may use the additive (alignment control agent) which accelerates a horizontal alignment and a vertical alignment. Various known additives can be used as the additive.

The thickness of the optically anisotropic layer is 0.1 to 10 μm, and preferably 0.5 to 5 μm from the viewpoint of thinning.
Further, the optically anisotropic layer may have a single layer structure or a laminated structure as long as it can realize the λ / 4 function. About such a structure, various well-known things can be used.

<Polarizing plate>
The polarizing plate preferably has a polarizing film protective film on one side or both sides of the polarizing film. In the production of a circularly polarizing plate, when a polarizing film and a λ / 4 plate are bonded together, it is possible to secure self-supporting if a polarizing film protective film is provided on at least one surface of the polarizing film. Fabrication with a roll becomes possible. As a polarizing film protective film, the same thing as the above-mentioned transparent support body is preferable.
The step of bonding the optically anisotropic layer side surface of the laminate A to the polarizing plate having the polarizing film protective film on at least one surface of the polarizing film may be directly bonded to the polarizing film, or the polarizing film It may be bonded to the protective film, or the polarizing plate may have another layer on the surface opposite to the surface having the polarizing film protective film. They may be combined. Moreover, it is preferable to stick together through an adhesive. Moreover, the specific suitable aspect in the bonding surface with the laminated body A of a polarizing plate is explained in full detail below.

  For example, a circularly polarizing plate having a broadband λ / 4 plate formed by laminating a λ / 4 plate and a λ / 2 plate, the circularly polarizing plate having a polarizing plate, a λ / 2 plate, and a λ / 4 plate in this order. When producing a plate, depending on the configuration of the polarizing plate to which the laminate A is bonded, the λ / 2 plate and / or λ / 4 plate to be prepared, and the preferred mode of the bonding method vary. Specifically, the following embodiments (A) and (B) are preferable.

  Aspect (A): When the polarizing plate has a polarizing film protective film on both sides of the polarizing film, the surface on the optically anisotropic layer side of the laminate A is placed on the polarizing plate (through the polarizing film protective film). It is preferable that the λ / 2 plate is bonded to the polarizing plate by bonding and peeling the transparent support from the laminate A. Further, when laminating the λ / 4 plate, the surface of the laminated body A on the optically anisotropic layer side is similarly laminated to the polarizing plate (via the λ / 2 plate), and the transparent support is laminated from the laminated body A. It is preferable to bond the λ / 4 plate by peeling (corresponding to Examples 2 and 4 described later).

Aspect (B): When the polarizing plate has a polarizing film protective film only on one surface of the polarizing film, the surface to be bonded to the laminate A of the polarizing plate is a polarizing film, From the viewpoint of obtaining similar bonding performance, the surface of the laminate A bonded to the polarizing film is preferably a cellulose acylate film.
For such a polarizing plate, first, as a λ / 2 plate, a liquid crystal composition containing a liquid crystal compound (for example, a discotic liquid crystal compound) is applied on a transparent support of a cellulose acylate film and aligned. It is preferable to prepare a λ / 2 plate having an optically anisotropic layer formed by curing and to bond the surface of the λ / 2 plate on the cellulose acylate film side to the polarizing film. Next, the surface on the optically anisotropic layer side of the laminate A to be a λ / 4 plate is bonded to the polarizing plate (via the λ / 2 plate), and the transparent support is peeled off from the laminate A. Λ / 4 plates are preferably bonded together (corresponding to Examples 1 and 3 described later).
In addition, the process of peeling a transparent support body from the laminated body A may be after the process of bonding the optically anisotropic layer side surface of the laminated body A to the polarizing film, or may be performed simultaneously.

  Hereinafter, the present invention will be described in more detail based on examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the following examples.

<Example 1>
The embodiment of FIG. 1 will be described in detail. In addition, as shown in FIG. 1, the circularly-polarizing plate 10 obtained by the following embodiments includes a polarizing film protective film 12, a polarizing film 14, a transparent support (cellulose acylate film) 16, and an alignment film 18. And an optically anisotropic layer 20, an adhesive 22, and an optical film 24 having an optically anisotropic layer and an alignment film.

(1) Production of cellulose acylate film (T1) (Preparation of cellulose ester solution A-1)
The following composition was put into a mixing tank and stirred while heating to dissolve each component to prepare a cellulose ester solution A-1.

Composition of cellulose ester solution A-1 ――――――――――――――――――――――――――――――――――
Cellulose acetate (degree of acetylation 2.86) 100 parts by mass Methylene chloride (first solvent) 320 parts by mass Methanol (second solvent) 83 parts by mass 1-butanol (third solvent) 3 parts by mass Triphenyl Phosphate 7.6 parts by mass, biphenyldiphenyl phosphate 3.8 parts by mass ――――――――――――――――――――――――――――――――― -

(Preparation of matting agent dispersion B-1)
The following composition was charged into a disperser and stirred to dissolve each component to prepare a matting agent dispersion B-1.

Composition of Matting Agent Dispersion B-1 ――――――――――――――――――――――――――――――――――
・ Silica particle dispersion (average particle size 16 nm)
"AEROSIL R972", manufactured by Nippon Aerosil Co., Ltd. 10.0 parts by mass, methylene chloride 72.8 parts by mass, methanol 3.9 parts by mass, butanol 0.5 parts by mass, cellulose ester solution A-1 10.3 parts by mass ――――――――――――――――――――――――――――――――――

(Preparation of UV absorber solution C-1)
The following composition was put into another mixing tank and stirred while heating to dissolve each component to prepare an ultraviolet absorber solution C-1.

Composition of UV absorber solution C-1 ――――――――――――――――――――――――――――――――――
UV absorber (UV-1 below) 10.0 parts by weight UV absorber (UV-2 below) 10.0 parts by weight Methylene chloride 55.7 parts by weight Methanol 10 parts by weight Butanol 1.3 parts by weight・ Cellulose ester solution A-1 12.9 parts by mass ――――――――――――――――――――――――――――――――――

(Production of cellulose ester film)
In a mixture of 94.6 parts by mass of cellulose acylate solution A-1 and 1.3 parts by mass of matting agent dispersion B-1, ultraviolet absorber (UV-1) and ultraviolet rays per 100 parts by mass of cellulose acylate An ultraviolet absorbent solution C-1 was added so that the amount of the absorbent (UV-2) was 1.0 part by mass, and each component was dissolved by stirring sufficiently while heating to prepare a dope. The obtained dope was heated to 30 ° C., and cast on a mirror surface stainless steel support, which was a drum having a diameter of 3 m, through a casting Giuser. The surface temperature of the support was set to −5 ° C., and the coating width was 1470 mm. The cast dope film was dried on the drum by applying a drying air of 34 ° C. at 150 m ³ / min, and peeled off from the drum with a residual solvent of 150%. During peeling, 15% stretching was performed in the transport direction (longitudinal direction). Thereafter, the film is conveyed while being gripped by a pin tenter (a pin tenter described in FIG. 3 of JP-A-4-1009) at both ends in the width direction (direction perpendicular to the casting direction), and stretched in the width direction. No processing was performed. Furthermore, it dried further by conveying between the rolls of a heat processing apparatus, and manufactured the cellulose acylate film (T1). The produced long cellulose acylate film (T1) had a residual solvent amount of 0.2%, a thickness of 60 μm, and Re and Rth at 550 nm of 0.8 nm and 40 nm, respectively.

(2) Production of cellulose acylate film (T2) (production of core layer cellulose acylate dope)
The following composition was put into a mixing tank and stirred to dissolve each component to prepare a cellulose acetate solution.
――――――――――――――――――――――――――――――――――
Cellulose acetate with an acetyl substitution degree of 2.88 100 parts by weight Ester oligomer A 10 parts by weight Polarizer durability improver (Chemical Formula-1) 4 parts by weight Ultraviolet absorber (UV-2) 2 parts by weight Methylene chloride (First solvent) 430 parts by mass Methanol (second solvent) 64 parts by mass ――――――――――――――――――――――――――――――― -

Polarizer durability improver

(Preparation of outer layer cellulose acylate dope)
10 parts by mass of the following matting agent solution was added to 90 parts by mass of the core layer cellulose acylate dope to prepare an outer layer cellulose acetate solution.
――――――――――――――――――――――――――――――――――
-Silica particles with an average particle size of 20 nm
"AEROSIL R972", manufactured by Nippon Aerosil Co., Ltd.)
2 parts by mass, methylene chloride (first solvent) 76 parts by mass, methanol (second solvent) 11 parts by mass, core layer cellulose acylate dope 1 part by mass ―――――――――――――――― ――――――――――――――――――

(Preparation of cellulose acylate film)
Three layers of the core layer cellulose acylate dope and the outer layer cellulose acylate dope were cast simultaneously on a drum at 20 ° C. from the casting port. The film was peeled off in a state where the solvent content was approximately 20% by mass, both ends in the width direction of the film were fixed with tenter clips, and the film was dried while being stretched 1.1 times in the lateral direction in a state where the residual solvent was 3 to 15%. Then, it dried further by conveying between the rolls of a heat processing apparatus, and produced the cellulose acylate film 2 with a thickness of 25 micrometers.

(3) Production of retardation plate (F1) (alkali saponification treatment)
The cellulose acylate film (T1) is passed through a dielectric heating roll having a temperature of 60 ° C., and the film surface temperature is raised to 40 ° C. Then, an alkali solution having the following composition is placed on the band surface of the film. The coating was applied at a coating amount of 14 ml / m ² using a coater and transported for 10 seconds under a steam far infrared heater manufactured by Noritake Co., Ltd., heated to 110 ° C. Subsequently, 3 ml / m ^{2 of} pure water was applied using the same bar coater. Next, washing with a fountain coater and draining with an air knife were repeated three times, and then transported to a drying zone at 70 ° C. for 10 seconds and dried to prepare an alkali saponified cellulose acylate film.

Alkaline solution composition ――――――――――――――――――――――――――――――――――
Potassium hydroxide 4.7 parts by weight Water 15.8 parts by weight Isopropanol 63.7 parts by weight Surfactant SF-1: C ₁₄ H ₂₉ O (CH ₂ CH ₂ O) ₂₀ H 1.0 part by weight Propylene glycol 14. 8 parts by mass ――――――――――――――――――――――――――――――――――

(Formation of alignment film)
On the surface of the cellulose acylate film (T1) subjected to the alkali saponification treatment, an alignment film coating solution (A) having the following composition was continuously applied with a # 14 wire bar. Drying was performed with warm air of 60 ° C. for 60 seconds, and further with warm air of 100 ° C. for 120 seconds. The degree of saponification of the modified polyvinyl alcohol used was 96.8%.

Composition of coating liquid for alignment film (A) ――――――――――――――――――――――――――――――――――
Modified polyvinyl alcohol-1 shown below 10 parts by weight Water 308 parts by weight Methanol 70 parts by weight Isopropanol 29 parts by weight Photopolymerization initiator (Irgacure 2959, manufactured by BASF) 0.8 parts by weight ―――――――――――― ――――――――――――――――――――――

[Modified polyvinyl alcohol-1]

(Formation of the first optically anisotropic layer (H))
The alignment film thus prepared was continuously rubbed. At this time, the longitudinal direction of the long film and the transport direction are parallel, and the angle formed between the longitudinal direction of the film and the rotation axis of the rubbing roller is 75 ° (the film width direction is 0 ° and the film longitudinal direction is 90 °). And the rotation axis of the rubbing roller is 15 ° when the clockwise direction is expressed as a positive value with reference to the film width direction as viewed from the alignment film side.

  An optically anisotropic layer coating liquid (A) containing a discotic liquid crystal compound having the following composition was continuously applied with a # 5.0 wire bar on the prepared alignment film to prepare a retardation film (F1). . The conveyance speed (V) of the film was 26 m / min. In order to dry the solvent of the coating solution and to mature the orientation of the discotic liquid crystal compound, it is heated with warm air of 130 ° C. for 90 seconds, followed by heating with warm air of 100 ° C. for 60 seconds, and UV irradiation is performed at 80 ° C. The alignment of the liquid crystal compound was fixed. The thickness of the first optical anisotropic layer (H) was 2.0 μm, and Re at 550 nm was 250 nm. The average inclination angle of the disk surface of the DLC compound with respect to the film surface was 90 °, and it was confirmed that the DLC compound was oriented perpendicular to the film surface. Further, when the slow axis angle of the first optically anisotropic layer (H) is parallel to the rotation axis of the rubbing roller and the film width direction is 0 ° (longitudinal direction is 90 °), the first optical anisotropic layer When viewed from the active layer (H) side, the slow axis was 15 °.

Composition of optically anisotropic layer coating solution (A) ――――――――――――――――――――――――――――――――――
Discotic liquid crystal-1 80 parts by mass Discotic liquid crystal-2 20 parts by mass alignment film interface alignment agent-1 0.55 parts by mass alignment film interface alignment agent-2 0.05 parts by mass fluorinated compound (FP-1) 0. 1 part by weight modified trimethylolpropane triacrylate 10 parts by weight photopolymerization initiator (Irgacure 907, manufactured by BASF) 3.0 parts by weight methyl ethyl ketone 200 parts by weight ―――――――――――――――――― ――――――――――――――――

Discotic liquid crystal-1

Discotic liquid crystal-2

Alignment film interfacial alignment agent-1

Alignment film interface alignment agent-2

Fluorine-containing compound (FP-1)

(4) Production of retardation plate (F2) (= Production of “laminate A”)

(Preparation of peelable support)
A peelable support was produced according to the same procedure as the production of the alignment film, except that the alignment film was produced as follows without subjecting the cellulose acylate film (T1) to an alkali saponification treatment.

(Formation of alignment film)
An alignment film coating solution (B) having the following composition was continuously applied to the cellulose acylate film (T1) with a # 14 wire bar. Drying was performed with warm air of 60 ° C. for 60 seconds, and further with warm air of 100 ° C. for 120 seconds.

Composition of alignment film coating solution (B) ――――――――――――――――――――――――――――――――――
Modified polyvinyl alcohol-2 below 10 parts by weight water 371 parts by weight Methanol 119 parts by weight Glutaraldehyde (crosslinking agent) 0.5 parts by weight citrate ester (AS3 manufactured by Sankyo Chemical Co., Ltd.) 0.175 parts by weight photopolymerization initiator (Irgacure 2959, manufactured by BASF) 2.0 parts by mass ――――――――――――――――――――――――――――――――――

[Modified polyvinyl alcohol-2]

(Formation of second optically anisotropic layer (Q))
The alignment film thus prepared was continuously rubbed. At this time, the longitudinal direction of the long film and the transport direction are parallel, and the angle formed between the longitudinal direction of the film and the rotation axis of the rubbing roller is 75 ° (the film width direction is 0 ° and the film longitudinal direction is 90 °). And the rotation axis of the rubbing roller is 15 ° when the clockwise direction is expressed as a positive value with reference to the film width direction as viewed from the alignment film side.

  An optically anisotropic layer coating liquid (B) containing a rod-like liquid crystal compound having the following composition was continuously applied to the prepared alignment film with a # 2.2 wire bar to prepare a retardation plate (F2). . The conveyance speed (V) of the film was 26 m / min. In order to dry the solvent of the coating liquid and ripen the alignment of the rod-like liquid crystal compound, the liquid crystal compound was aligned by heating at 60 ° C. for 60 seconds and UV irradiation at 60 ° C. The thickness of the second optically anisotropic layer (Q) was 0.8 μm, and Re at 550 nm was 120 nm. The average inclination angle of the long axis of the rod-like liquid crystal compound with respect to the film surface was 0 °, and it was confirmed that the liquid crystal compound was aligned horizontally with respect to the film surface. Further, when the angle of the slow axis of the second optical anisotropic layer (Q) is perpendicular to the rotation axis of the rubbing roller and the film width direction is 0 ° (longitudinal direction is 90 °), the second optical anisotropic layer When viewed from the active layer (Q) side, the slow axis was 105 °.

Composition of optically anisotropic layer coating solution (B) ――――――――――――――――――――――――――――――――――
Rod-like liquid crystal compound-1 80 parts by mass Rod-like liquid crystal compound-2 20 parts by mass Photopolymerization initiator (Irgacure 907, manufactured by BASF) 3 parts by mass sensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.) 1 part by mass Fluorine compound (FP-2) 0.3 parts by mass Methyl ethyl ketone 193 parts by mass ――――――――――――――――――――――――――――――――――

[Bar-shaped liquid crystal compound-1]

[Bar-shaped liquid crystal compound-2]

[Fluorine-containing compound (FP-2)]

(5) Production of Polarizing Film A polyvinyl alcohol (PVA) film having a thickness of 80 μm is dyed by dipping in an iodine aqueous solution having an iodine concentration of 0.05 mass% at 30 ° C. for 60 seconds, and then boric acid concentration is 4 mass%. While being immersed in an aqueous boric acid solution for 60 seconds, the film was longitudinally stretched 5 times the original length and then dried at 50 ° C. for 4 minutes to obtain a polarizing film having a thickness of 20 μm.

(6) Saponification of polarizing film protective film and retardation plate The cellulose acylate film (T2) produced above was immersed in an aqueous solution of sodium hydroxide at 55 ° C. at 1.5 mol / liter and then sufficiently hydroxylated with water. The sodium was washed away. Then, after being immersed in a diluted sulfuric acid aqueous solution at 0.005 mol / liter at 35 ° C. for 1 minute, it was immersed in water to sufficiently wash away the diluted sulfuric acid aqueous solution. Finally, the sample was thoroughly dried at 120 ° C. Similarly, the retardation film (F1) was also saponified.

(7) Preparation of polarizing plate (P1) The surface of the transparent support of the retardation plate (F1) saponified in (6), the polarizing film prepared in (5), and the polarizing film protective film saponified in (6) Were continuously bonded using a polyvinyl alcohol-based adhesive. In this way, a long polarizing plate (P1) was produced. The absorption axis of the polarizing film coincides with the longitudinal direction of the polarizing plate. When the width direction of the polarizing film is 0 ° (longitudinal direction is 90 °), the first optical anisotropic layer (H) side When viewed, the absorption axis of the polarizing film was 90 °, and the slow axis of the first optically anisotropic layer (H) was 15 °.

(8) Preparation of circularly polarizing plate (P2) The surface on which the optically anisotropic layer of the polarizing plate (P1) is coated and the surface of the optically anisotropic layer of the retardation plate (F2) Bonding was continuously performed using an adhesive, and at the same time, the above-described peelable support was peeled between the cellulose acylate film (T1) and the alignment film. In this way, a circularly polarizing plate (P2) in which the polarizing film, the first optically anisotropic layer (H), and the second optically anisotropic layer (Q) were long and laminated in this order was produced. . The absorption axis of the polarizing film coincides with the longitudinal direction of the polarizing plate. When the width direction of the polarizing film is 0 ° (longitudinal direction is 90 °), the second optically anisotropic layer (Q) side When viewed, the absorption axis of the polarizing film was 90 °, the slow axis of the first optical anisotropic layer (H) was 15 °, and the slow axis of the second optical anisotropic layer (Q) was 75 °. It was.

<Example 2>
The embodiment of FIG. 2 will be described in detail. In addition, as shown in FIG. 2, the circularly-polarizing plate 100 obtained by the following embodiments includes a polarizing film protective film 30, a polarizing film 32, a transparent support (cellulose acylate film) 34, and an adhesive 36. And an optical film 38 having an optically anisotropic layer and an alignment film, an adhesive 40, and an optical film 42 having an optically anisotropic layer and an alignment film.

(9) Production of retardation plate (F3) (= Production of “laminate A”)

(Preparation of peelable support)
A peelable support was produced according to the same procedure as the production of the alignment film, except that the alignment film was produced as follows without subjecting the cellulose acylate film (T1) to an alkali saponification treatment.

(Formation of alignment film)
The alignment film coating solution (A) used in (3) was continuously applied to the cellulose acylate film (T1) with a # 14 wire bar. Drying was performed with warm air of 60 ° C. for 60 seconds, and further with warm air of 100 ° C. for 120 seconds. The degree of saponification of the modified polyvinyl alcohol used was 96.8%.

(Formation of the first optically anisotropic layer (H))
The alignment film thus prepared was continuously rubbed. At this time, the longitudinal direction of the long film and the transport direction are parallel, and the angle formed between the longitudinal direction of the film and the rotation axis of the rubbing roller is 75 ° (the film width direction is 0 ° and the film longitudinal direction is 90 °). And the rotation direction of the rubbing roller is 165 ° when the clockwise direction is expressed as a positive value based on the film width direction when observed from the alignment film side.

  The optically anisotropic layer coating solution (A) used in (3) was continuously applied with a # 5.0 wire bar on the prepared alignment film to prepare a retardation plate (F3). The conveyance speed (V) of the film was 26 m / min. In order to dry the solvent of the coating solution and to mature the orientation of the discotic liquid crystal compound, it is heated with warm air of 130 ° C. for 90 seconds, followed by heating with warm air of 100 ° C. for 60 seconds, and UV irradiation is performed at 80 ° C. The alignment of the liquid crystal compound was fixed. The thickness of the first optical anisotropic layer (H) was 2.0 μm. The average inclination angle of the disk surface of the DLC compound with respect to the film surface was 90 °, and it was confirmed that the DLC compound was oriented perpendicular to the film surface. Further, when the slow axis angle of the first optically anisotropic layer (H) is parallel to the rotation axis of the rubbing roller and the film width direction is 0 ° (longitudinal direction is 90 °), the first optical anisotropic layer When viewed from the active layer (H) side, the slow axis was 165 °.

(10) Production of Polarizing Film A polyvinyl alcohol (PVA) film having a thickness of 80 μm is dyed by dipping in an aqueous iodine solution having an iodine concentration of 0.05 mass% at 30 ° C. for 60 seconds, and then boric acid concentration is 4 mass%. While being immersed in an aqueous boric acid solution for 60 seconds, the film was longitudinally stretched 5 times the original length and then dried at 50 ° C. for 4 minutes to obtain a polarizing film having a thickness of 20 μm.

(11) Saponification of Polarizing Film Protective Film After the cellulose acylate film (T2) was immersed in an aqueous sodium hydroxide solution at 55 ° C. at 1.5 mol / liter, the sodium hydroxide was sufficiently washed away with water. Then, after being immersed in a diluted sulfuric acid aqueous solution at 0.005 mol / liter at 35 ° C. for 1 minute, it was immersed in water to sufficiently wash away the diluted sulfuric acid aqueous solution. Finally, the sample was thoroughly dried at 120 ° C.

(12) Production of polarizing plate (P3) Polarizing film protective film saponified in (11), polarizing film produced in (10), and polarizing film protective film saponified in (11) And bonded together continuously. In this way, a long polarizing plate (P3) was produced.

(13) Preparation of polarizing plate (P4) The polarizing plate (P3) and the surface of the optically anisotropic layer of the retardation plate (F3) are continuously bonded using an adhesive, and at the same time, a peelable support is attached. The cellulose acylate film (T1) was peeled between the alignment film. In this way, a long polarizing plate (P4) was produced. The absorption axis of the polarizing film coincides with the longitudinal direction of the polarizing plate. When the width direction of the polarizing film is 0 ° (longitudinal direction is 90 °), the first optical anisotropic layer (H) side When viewed, the absorption axis of the polarizing film was 90 °, and the slow axis of the first optically anisotropic layer (H) was 15 °.

(14) Preparation of circularly polarizing plate (P5) The surface of the alignment film of the polarizing plate (P4) and the surface of the optically anisotropic layer of the retardation plate (F2) are continuously formed using an adhesive. At the same time, the peelable support was peeled between the cellulose acylate film (T1) and the alignment film. In this way, a circularly polarizing plate (P5) in which the polarizing film, the first optically anisotropic layer (H), and the second optically anisotropic layer (Q) were long and laminated in this order was produced. . The absorption axis of the polarizing film coincides with the longitudinal direction of the polarizing plate. When the width direction of the polarizing film is 0 ° (longitudinal direction is 90 °), the second optically anisotropic layer (Q) side When viewed, the absorption axis of the polarizing film was 90 °, the slow axis of the first optical anisotropic layer (H) was 15 °, and the slow axis of the second optical anisotropic layer (Q) was 75 °. It was.

<Example 3>
(15) Preparation of retardation plate (F4) In preparation of retardation plate (F1) described in Example 1, instead of using cellulose acylate film (T1), cellulose acylate film prepared in (2) An alignment film and a first optically anisotropic layer (H) were formed in the same manner as in the method described in (3) except that (T2) was used, and a retardation plate (F4) was produced. The thickness of the first optical anisotropic layer (H) was 2.0 μm, and Re at 550 nm was 250 nm. The average inclination angle of the disk surface of the DLC compound with respect to the film surface was 90 °, and it was confirmed that the DLC compound was oriented perpendicular to the film surface. Further, when the slow axis angle of the first optically anisotropic layer (H) is parallel to the rotation axis of the rubbing roller and the film width direction is 0 ° (longitudinal direction is 90 °), the first optical anisotropic layer When viewed from the active layer (H) side, the slow axis was 15 °.

(16) Production of retardation plate (F5) (= Production of “laminate A”)
In the same manner as in Example 1, the long cellulose acylate film (T1) was saponified, and an alignment film (B) was formed thereon.

(Formation of second optically anisotropic layer (Q))
The alignment film thus prepared was continuously rubbed. At this time, the longitudinal direction of the long film and the transport direction are parallel, and the angle formed between the longitudinal direction of the film and the rotation axis of the rubbing roller is 75 ° (the film width direction is 0 ° and the film longitudinal direction is 90 °). And the rotation axis of the rubbing roller is 15 ° when the clockwise direction is expressed as a positive value with reference to the film width direction as viewed from the alignment film side.

  The optically anisotropic layer coating liquid (A) containing the above discotic liquid crystal compound was continuously applied onto the prepared alignment film with a # 2.4 wire bar to prepare a retardation film (F5). The conveyance speed (V) of the film was 26 m / min. In order to dry the solvent of the coating solution and to mature the orientation of the discotic liquid crystal compound, it is heated with warm air of 130 ° C. for 90 seconds, followed by heating with warm air of 100 ° C. for 60 seconds, and UV irradiation is performed at 80 ° C. The alignment of the liquid crystal compound was fixed. The thickness of the second optically anisotropic layer (Q) was 0.96 μm, and Re at 550 nm was 120 nm. The average inclination angle of the disk surface of the DLC compound with respect to the film surface was 90 °, and it was confirmed that the DLC compound was oriented perpendicular to the film surface. Further, when the angle of the slow axis of the second optical anisotropic layer (Q) is perpendicular to the rotation axis of the rubbing roller and the film width direction is 0 ° (longitudinal direction is 90 °), the second optical anisotropic layer When viewed from the active layer (Q) side, the slow axis was 105 °.

(17) Production of Polarizing Plate (P6) The cellulose acylate film (T2) and the retardation plate (F4) were saponified in the same manner as the saponification of the polarizing film protective film and retardation plate described in Example 1 (6). . The surface of the saponified phase difference plate (F4) transparent support, the polarizing film prepared in (5), and the saponified cellulose acylate film (T2) are continuously bonded using a polyvinyl alcohol adhesive. It was. In this way, a long polarizing plate (P6) was produced. The absorption axis of the polarizing film coincides with the longitudinal direction of the polarizing plate. When the polarizing film has a width direction of 0 ° (longitudinal direction is 90 °), it is viewed from the first optically anisotropic layer (H) side. The absorption axis of the polarizing film was 90 °, and the slow axis of the first optically anisotropic layer (H) was 15 °.

(18) Preparation of circularly polarizing plate (P7) The surface of the polarizing plate (P6) on which the optically anisotropic layer is applied and the surface of the optically anisotropic layer of the retardation plate (F5) described above Bonding was continuously performed using an adhesive, and at the same time, the above-described peelable support was peeled between the cellulose acylate film (T1) and the alignment film. In this way, a circularly polarizing plate (P7) in which the polarizing film, the first optically anisotropic layer (H), and the second optically anisotropic layer (Q) were long and laminated in this order was produced. . The absorption axis of the polarizing film coincides with the longitudinal direction of the polarizing plate. When the width direction of the polarizing film is 0 ° (longitudinal direction is 90 °), the second optically anisotropic layer (Q) side When viewed, the absorption axis of the polarizing film was 90 °, the slow axis of the first optical anisotropic layer (H) was 15 °, and the slow axis of the second optical anisotropic layer (Q) was 75 °. It was.

<Example 4>
(19) Production of retardation plate (F6) (formation of alignment film)
In the formation of the alignment film of the retardation plate film (F1) described in Example 1, the alignment film coating liquid (C) having the following composition was used in the same manner, and the alignment was performed on the saponified cellulose acylate film (T1). A film was formed.
――――――――――――――――――――――――――――――――――
The following polyvinyl alcohol 10 parts by mass Water 371 parts by mass Methanol 119 parts by mass Glutaraldehyde (crosslinking agent) 0.5 parts by mass Citric acid ester (manufactured by Sankyo Chemical Co., Ltd.) 0.175 parts by mass ――――――――――――――――――――――――――

[Polyvinyl alcohol]

(Formation of second optically anisotropic layer (Q))
The alignment film thus prepared was continuously rubbed. At this time, the longitudinal direction of the long film and the transport direction are parallel, and the angle formed between the longitudinal direction of the film and the rotation axis of the rubbing roller is 75 ° (the film width direction is 0 ° and the film longitudinal direction is 90 °). And the rotation axis of the rubbing roller is 15 ° when the clockwise direction is expressed as a positive value with reference to the film width direction as viewed from the alignment film side.

  An optically anisotropic layer coating liquid (C) containing the following discotic liquid crystal compound was continuously applied on the prepared alignment film with a # 2.4 wire bar to prepare a retardation film (F6). The conveyance speed (V) of the film was 26 m / min. In order to dry the solvent of the coating solution and to mature the orientation of the discotic liquid crystal compound, it is heated with warm air of 130 ° C. for 90 seconds, followed by heating with warm air of 100 ° C. for 60 seconds, and UV irradiation is performed at 80 ° C. The alignment of the liquid crystal compound was fixed. The thickness of the second optically anisotropic layer (Q) was 0.96 μm, and Re at 550 nm was 120 nm. The average inclination angle of the disk surface of the DLC compound with respect to the film surface was 90 °, and it was confirmed that the DLC compound was oriented perpendicular to the film surface. Further, when the angle of the slow axis of the second optical anisotropic layer (Q) is perpendicular to the rotation axis of the rubbing roller and the film width direction is 0 ° (longitudinal direction is 90 °), the second optical anisotropic layer When viewed from the active layer (Q) side, the slow axis was 105 °. The cellulose acylate film (T1) and the alignment film (C) were in close contact, and the second optical anisotropic layer (Q) could be peeled from the alignment film (C).

Composition of coating solution (C) for optically anisotropic layer ―――――――――――――――――――――――――――――――――――――
Discotic liquid crystal-1 80 parts by mass Discotic liquid crystal-2 20 parts by mass alignment film interface aligning agent-1 0.55 parts by mass fluorinated compound (FP-1) 0.2 parts by mass fluorinated compound (FP-2) 0 .1 part by mass fluorine-containing compound (FP-3) 0.05 part by mass ethylene oxide-modified trimethylolpropane triacrylate 10 parts by mass photopolymerization initiator (Irgacure 819, manufactured by BASF) 3.0 parts by mass methyl ethyl ketone 200 parts by mass ――――――――――――――――――――――――――――――――――――

[Fluorine-containing compound (FP-3)]

(20) Production of Circular Polarizing Plate (P8) A long polarizing plate (P4) in which the polarizing plate (P3) and the first optically anisotropic layer (H) are bonded together by the method described in Example 2. Was made. The surface of the alignment film of the polarizing plate (P4) and the surface of the optically anisotropic layer of the retardation plate (F6) are continuously bonded using an adhesive, and at the same time, the peelable support is bonded to the alignment film (C ) And the second optically anisotropic layer (Q). In this way, a circularly polarizing plate (P8) was prepared in which the polarizing film, the first optically anisotropic layer (H), and the second optically anisotropic layer (Q) were long and laminated in this order. . The absorption axis of the polarizing film coincides with the longitudinal direction of the polarizing plate. When the width direction of the polarizing film is 0 ° (longitudinal direction is 90 °), the second optically anisotropic layer (Q) side When viewed, the absorption axis of the polarizing film was 90 °, the slow axis of the first optical anisotropic layer (H) was 15 °, and the slow axis of the second optical anisotropic layer (Q) was 75 °. It was.

<Comparative example>
A circularly polarizing plate was produced in the same manner except that the cellulose acylate film was subjected to alkali saponification treatment in the production of the peelable support in Examples 1 and 2, but it could not be peeled off successfully.

DESCRIPTION OF SYMBOLS 10 Circularly-polarizing plate 12 Polarizing film protective film 14 Polarizing film 16 Transparent support 18 Orientation film 20 Optical anisotropic layer 22 Adhesive 24 Optical film 30 Polarizing film protective film 32 Polarizing film 34 Transparent support 36 Adhesive 38 Optical film 40 Adhesive 42 Optical film 100 Circular polarizing plate

Claims (3)

A method for producing a circularly polarizing plate having an optical laminate and a polarizing film,
A step of producing a laminate A by forming an alignment film on the transparent support without forming a saponification treatment on the transparent support, and forming an optically anisotropic layer containing a liquid crystal compound on the alignment film. And a step of preparing a polarizing plate having a polarizing film protective film on at least one surface of the polarizing film; and a surface of the laminate A on the side of the optically anisotropic layer is bonded to the polarizing plate and is more transparent than the laminate A A method for producing a circularly polarizing plate, comprising a step of producing a circularly polarizing plate having an optical laminate and a polarizing film by peeling off the support. The transparent support is a cellulose acylate film,
The optical laminate has a first optical anisotropic layer (H) and a second optical anisotropic layer (Q),
At least one of the first optical anisotropic layer (H) and the second optical anisotropic layer (Q) is an optical anisotropic layer formed from a composition containing a liquid crystal compound,
ReH (550) and ReQ (550) which are in-plane retardation values of the first optically anisotropic layer (H) and the second optically anisotropic layer (Q) measured at a wavelength of 550 nm are expressed by the following formula (1). The manufacturing method of the circularly-polarizing plate of Claim 1 which satisfies the relationship of (2).
Formula (1) ReH (550) = 2 × ReQ (550) ± 50
Formula (2) 100 ≦ ReQ (550) ≦ 180 The first optically anisotropic layer (H) and the second optically anisotropic layer (Q) are both optically anisotropic layers formed from a composition containing a liquid crystal compound,
At least one of the first optically anisotropic layer (H) and the second optically anisotropic layer (Q) bonds the optically anisotropic layer side surface of the laminate A to the polarizing plate, and the laminate A The manufacturing method of the circularly-polarizing plate of Claim 2 produced by peeling a transparent support body more.