JP6561449B2 - Method for producing retardation film with polarizer and method for evaluating retardation film - Google Patents

Description

  The present invention relates to a method for producing a retardation film with a polarizer and a method for evaluating a retardation film.

Conventionally, in a liquid crystal display device, various techniques have been developed in order to improve the problem of viewing angle dependency. As one of them, a retardation film having a retardation layer exhibiting birefringence is used as a liquid crystal cell. Liquid crystal display devices disposed between polarizing plates are known (for example, Patent Documents 1 and 2).
As the retardation film having the retardation layer, an alignment layer having an alignment regulating force for aligning liquid crystalline compounds in a certain direction on a resin substrate, and formed on the alignment layer and arranged in a certain direction Those having a retardation layer containing a liquid crystal compound are used.

  Conventionally, as a flat panel display, a two-dimensional display has been mainstream, but in recent years, a flat panel display capable of three-dimensional display has begun to attract attention. Further, in future flat panel displays, it is a natural tendency to be capable of three-dimensional display, and flat panel displays capable of three-dimensional display are being studied in a wide range of fields.

In order to perform three-dimensional display on a flat panel display, it is usually necessary to display a right-eye video and a left-eye video separately to the viewer in some manner. As a method for separately displaying the right-eye video and the left-eye video, for example, a passive method is known. Such a passive three-dimensional display method will be described with reference to the drawings. FIG. 3 is a schematic diagram illustrating an example of a liquid crystal display device capable of displaying a three-dimensional image in a passive manner. As shown in FIG. 3, in this method, first, the pixels constituting the flat panel display are classified into two types of pixels, a right-eye video display pixel and a left-eye video display pixel, and the right-eye pixel is displayed in the display display area. And the left-eye pixels are arranged in a pattern so that they are adjacent to each other. One group of pixels displays a right-eye image, and the other group of pixels displays a left-eye image. Also, using a linear retardation plate and a pattern retardation film (hereinafter sometimes simply referred to as a pattern retardation film) in which a patterned retardation layer corresponding to the arrangement pattern of the pixel is formed, The image and the image for the left eye are each converted into circularly polarized light. In addition, the viewer wears circularly polarized glasses that employ a right-eye lens and a left-eye lens, and the right-eye image passes only through the right-eye lens, and the left-eye image passes only through the left-eye lens. Like that. In this way, the right-eye video reaches only the right eye, and the left-eye video reaches only the left eye, thereby enabling three-dimensional display.
Such a passive method has an advantage that three-dimensional display can be easily performed by using the pattern retardation film and the corresponding circular polarizing glasses.

  As the above-mentioned pattern retardation film, for example, in Patent Document 3, a photo-alignment layer in which the alignment regulating force is controlled in a pattern on a glass substrate, and the alignment of the liquid crystalline compound formed on the photo-alignment layer are described above. A pattern retardation plate having a retardation layer (liquid crystal layer) patterned so as to correspond to the pattern of the photo-alignment layer is disclosed.

In both of the retardation film and the pattern retardation film, the liquid crystalline compounds are arranged in a certain direction by the alignment layer, and the optical axis is required to be constant throughout the film or in each pattern in the film.
Conventionally, attempts have been made to improve the surface smoothness of the retardation layer and reduce unevenness in the retardation film by including a surfactant (leveling agent) in the retardation layer (liquid crystal layer) ( For example, Patent Documents 4 and 5).

JP-A-3-67219 JP-A-4-322223 JP 2005-49865 A JP 2004-198511 A JP 2009-242564 A

  Conventionally, since the retardation film and the polarizer were bonded together using the pressure-sensitive adhesive sheet, the leveling agent could be used without any particular limitation as long as a retardation film with reduced unevenness and no appearance problems could be obtained. . However, further thinning is demanded as a retardation film with a polarizer. For this reason, it has been studied to obtain a thinner retardation film with a polarizer by applying an adhesive on the retardation layer of the retardation film formed into a member and bonding it to the polarizing plate. For example, a pattern retardation film (FPR: Film Patterned Retarder) is particularly required to apply an adhesive to the surface of a retardation layer of a retardation film formed into a member and attach another film such as a polarizer. Yes. However, when a retardation film containing a surfactant (leveling agent) is used in the retardation layer, the adhesive layer may be repelled when the adhesive is applied onto the retardation layer, which may cause a defect in the adhesive layer. Occurs, and the liquid crystal display device is uneven.

  The present invention has been made in view of the above problems, and an adhesive used for attaching the retardation film and a polarizer while using a retardation film including a retardation layer containing a leveling agent. Of a retardation film with a polarizer in which defects of the adhesive layer due to the repellency are suppressed, and a retardation film capable of easily evaluating the suitability of the adhesive on the surface of the retardation layer without applying an adhesive The purpose is to provide an evaluation method.

The method for producing a phase difference film with a polarizer according to the present invention is a method for producing a phase difference film with a polarizer, comprising a polarizer laminated on a phase difference film via an adhesive,
A step of preparing a retardation film in which an alignment layer and a retardation layer are provided in this order on one surface side of a transparent substrate, and the retardation layer contains a liquid crystal compound and a leveling agent;
Measuring the surface free energy of the retardation layer surface of the retardation film;
When the measurement result of the dispersion component (d) of the surface free energy is 28 mN / m or more and 40 mN / m or less, and the measurement result of the non-dispersion component of the surface free energy is 5 mN / m or less, the phase difference A determination step for determining that the adhesiveness of the surface of the layer is acceptable;
The determination step includes a step of laminating a polarizer after applying the adhesive composition on the retardation layer determined to have acceptable adhesive properties.

In the method for evaluating a retardation film according to the present invention, an alignment layer and a retardation layer are provided in this order on one side of a transparent substrate, and the retardation layer contains a liquid crystalline compound and a leveling agent. A step of preparing a retardation film;
Measuring the surface free energy of the retardation layer surface of the retardation film;
Based on the results of the dispersion component (d) and the non-dispersion component in the measurement of the surface free energy, the measurement result of the dispersion component (d) of the surface free energy is 28 mN / m or more and 40 mN / m or less, When the measurement result of the non-dispersion component of the free energy is 5 mN / m or less, the adhesive suitability on the retardation layer surface is allowed and whether the adhesive suitability on the retardation layer surface is allowed or not. And a step of evaluating.

  According to the present invention, while using a retardation film having a retardation layer containing a leveling agent, there is a drawback of the adhesive layer due to the repellency of the adhesive used to attach the retardation film and the polarizer. It is possible to provide a method for producing a retarded retardation film with a polarizer and a retardation film evaluation method that can easily evaluate the adhesive suitability of the surface of the retardation layer without applying an adhesive. .

It is a schematic cross section which shows an example of the phase difference film used for this invention. It is a schematic cross section which shows an example of the phase difference film with a polarizer obtained by the manufacturing method which concerns on this invention. It is the schematic which shows an example of the liquid crystal display device which can display a three-dimensional image | video with a passive system.

Hereinafter, the evaluation method of the retardation film according to the present invention and the production method of the retardation film with a polarizer will be described in order.
In the present invention, the optical axis means a slow axis.
In the present invention, the alignment regulating force means an interaction that aligns liquid crystal compounds in the retardation layer in a specific direction.
In the present invention, the retardation film includes a pattern retardation film unless otherwise specified.
In the present invention, (meth) acryl represents each of acryl or methacryl, and (meth) acrylate represents each of acrylate or methacrylate.

[Evaluation method of retardation film]
The retardation film evaluation method according to the present invention (hereinafter sometimes simply referred to as an evaluation method) is provided with an alignment layer and a retardation layer in this order on one side of a transparent substrate, and the retardation layer is provided in this order. A step of preparing a retardation film containing a liquid crystalline compound and a leveling agent (hereinafter sometimes simply referred to as a retardation film preparation step);
A step of measuring the surface free energy of the surface of the retardation layer of the retardation film (hereinafter sometimes simply referred to as a measurement step);
A step of evaluating whether or not the suitability of the adhesive on the surface of the retardation layer is allowed based on the result of the dispersion component (d) in the measurement of the surface free energy (hereinafter sometimes referred to simply as an evaluation step); It is characterized by having.

  As a result of intensive studies on the correlation between the suitability of the adhesive on the surface of the retardation layer of the retardation film and the physical properties of the surface of the retardation layer, the present inventors have determined that the dispersion component of the surface free energy measurement on the surface of the retardation layer ( It is found that the result of d) has a correlation with the suitability of the adhesive on the surface of the retardation layer, and whether the suitability of the adhesive on the surface of the retardation layer is allowed or not can be easily applied without applying an adhesive. The evaluation method of the present invention that can be evaluated has been completed. It is considered that the ease of wetting and spreading of the adhesive composition with respect to the surface of the retardation layer is influenced by the correspondence between the sizes of the components of the surface free energy. The retardation layer of the retardation film used in the production method of the present invention contains a leveling agent, thereby reducing the surface tension of the coating film when forming the retardation layer and improving the surface smoothness. On the other hand, since the retardation layer contains a leveling agent, it is considered that the adhesive may be repelled when the adhesive is applied to the surface. Therefore, it is presumed that the retardation layer has an interaction with a substance in contact with the surface of the retardation layer by containing a leveling agent. Therefore, the ease of wetting and spreading of the adhesive with respect to the surface of the retardation layer can be estimated by using, as an index, the size of the dispersed component (d) that is relatively small in the influence of the substance in contact with the surface free energy component. Based on the result of the dispersion component (d), it is considered possible to evaluate whether or not the adhesive suitability is acceptable.

The evaluation method of the present invention has at least (1) a preparation step, (2) a measurement step, and (3) an evaluation step, and may have other steps as necessary. is there.
Hereafter, each process of the evaluation method of such this invention is demonstrated in order.

(1) Preparatory step The preparatory step is a step of preparing a retardation film in which an alignment layer and a retardation layer are provided in this order on at least one surface side of a transparent substrate.

<Phase difference film>
As shown in FIG. 1, the retardation film 10 is a film in which an alignment layer 2 and a retardation layer 3 are provided in this order on a transparent substrate 1, and has other layers. Is also good.

(Transparent substrate)
The transparent substrate has a function of supporting the alignment layer and the retardation layer. As the transparent substrate, a known transparent substrate used for the retardation film may be appropriately selected and used. Examples of the transparent substrate include acetyl cellulose resins such as triacetyl cellulose, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, olefin resins such as polyethylene and polymethylpentene, acrylic resins, polyurethane resins, Examples thereof include polyether sulfone, polycarbonate, polysulfone, polyether, polyether ketone, acrylonitrile, methacrylonitrile, cycloolefin polymer, and cycloolefin copolymer.

  As the transparent substrate, a long transparent substrate having such a length that can be wound up in a roll shape can be installed in a roll-to-roll apparatus, and is excellent in mass productivity. preferable. Specifically, the length of the long transparent substrate is preferably 10 m or more, more preferably 50 to 6000 m, and even more preferably 500 to 6000 m. .

  The transparent substrate preferably has a transmittance in the visible light region of 80% or more, and more preferably 90% or more. Here, the transmittance | permeability of a transparent base material can be measured by JISK7361-1 (the test method of the total light transmittance of a plastic-transparent material).

  As the transparent substrate, it is preferable that the retardation is low. More specifically, the in-plane retardation value (Re value) of the transparent substrate is preferably in the range of 0 nm to 10 nm, more preferably in the range of 0 nm to 5 nm, and 0 nm to 3 nm. More preferably, it is within the range. Since the in-plane retardation tends to approach zero, the transparent substrate is preferably formed using a resin such as an acetyl cellulose resin, a cycloolefin polymer, a cycloolefin copolymer, or an acrylic resin.

  The thickness of the transparent substrate may be set as appropriate within the range where the necessary self-supporting property can be imparted to the retardation film, depending on the use of the retardation film, etc., but preferably within the range of 25 μm to 125 μm. In the range of 30 μm to 100 μm, more preferably in the range of 40 μm to 80 μm. If it is more than the said lower limit, it is excellent in the self-supporting property of retardation film. Moreover, if it is below the said upper limit, processing, such as cutting, is easy.

(Orientation layer)
The alignment layer is a layer for aligning liquid crystal compounds contained in a retardation layer described later in a certain direction. In the present invention, the alignment layer comprises an alignment layer forming composition or a cured product thereof. In addition, in this invention, hardened | cured material means what became hard through chemical reaction.

The composition for forming an alignment layer can be appropriately selected from conventionally known ones. The composition of the alignment layer forming ink is not particularly limited, and is appropriately selected depending on the combination with a means for imparting alignment regulating force.
The means for imparting alignment regulating force to the alignment layer can be a conventionally known one, and examples thereof include a rubbing method, a photo-alignment method, and a shaping method.

  When the alignment layer is formed by a photo-alignment method, a photo-alignment composition containing a photo-alignment material that exhibits an alignment regulating force when irradiated with polarized light is used as the alignment layer-forming composition. The photo-alignment material may be a photodimerization type material or a photoisomerization type material. Specifically, for example, cinnamate, coumarin, benzylidene phthalimidine, benzylidene acetophenone, diphenylacetylene, stilbazole, uracil, quinolinone, maleimide, or a polymer having a cinnamylideneacetic acid derivative, among others, cinnamate, or A polymer having at least one of coumarin, a polymer having cinnamate and coumarin, and derivatives thereof are preferably used. Specific examples of such a photodimerization type material are described in, for example, JP-A-9-118717, JP-T-10-506420, JP-T2003-505561, and WO2010 / 150748. A compound can be mentioned.

  The photoalignment composition may contain a compound other than the photoalignment material as necessary. Such a compound is not particularly limited as long as it does not impair the alignment regulating force of the alignment layer. For example, a monomer or oligomer having a polymerizable group (hereinafter, simply referred to as a polymerizable monomer or a polymerizable oligomer) may be used. Preferably used.

  Examples of the polymerizable monomer or polymerizable oligomer used in the present invention include a monofunctional monomer having one (meth) acrylate group (for example, ethyl (meth) acrylate, ethylhexyl (meth) acrylate, styrene, methylstyrene, N-vinylpyrrolidone) and polyfunctional monomers having two or more (meth) acrylate groups (for example, polymethylolpropane tri (meth) acrylate, hexanediol (meth) acrylate, triethylene (polypropylene) glycol diacrylate, tripropylene glycol) Di (meth) acrylate, diethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (Meth) acrylate, neopentyl glycol di (meth) acrylate, isocyanuric acid poly (meth) acrylate (for example, isocyanuric acid EO diacrylate)) and bisphenol fluorene derivatives (for example, bisphenoxyethanol full orange (meth) acrylate, bisphenol full) Orange epoxy (meth) acrylate) and the like can be used alone or in combination of two or more.

  The composition for forming an alignment layer usually contains a solvent. The solvent used in the composition for forming an alignment layer can be appropriately selected from solvents that do not react with each component in the composition and can dissolve or disperse each component. Specific examples of the solvent used in the composition for forming an alignment layer include hydrocarbon solvents such as benzene and hexane, ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, tetrahydrofuran, 1,2-dimethoxyethane, propylene glycol. Ether solvents such as monoethyl ether (PGME), alkyl halide solvents such as chloroform and dichloromethane, ester solvents such as methyl acetate, ethyl acetate, butyl acetate and propylene glycol monomethyl ether acetate, N, N-dimethylformamide, etc. Amide solvents, sulfoxide solvents such as dimethyl sulfoxide, anone solvents such as cyclohexane, alcohol solvents such as methanol, ethanol, and propanol. Not shall. The solvent may be used alone or as a mixed solvent of two or more solvents.

  The alignment layer forming composition absorbs ultraviolet rays as necessary, a polymerization initiator, a polymerization inhibitor, an antioxidant for suppressing changes to oxygen, a light stabilizer for suppressing changes to light. Even if it contains an ultraviolet absorber, a viscosity modifier for adjusting the viscosity, a refractive index modifier for adjusting the refractive index, a fluorine-based or silicon-based lubricant for improving moldability, etc. good. These may be appropriately selected from conventionally known materials.

  The thickness of the alignment layer may be set as appropriate as long as the liquid crystal compounds in the retardation layer described later can be aligned in a certain direction. The thickness of the alignment layer is usually in the range of 1 nm to 1000 nm, and preferably in the range of 60 nm to 300 nm.

(Retardation layer)
The retardation layer is a layer in which liquid crystal compounds are regularly arranged and phase retardation is imparted by the alignment regulating force of the alignment layer. In the present invention, the retardation layer contains a liquid crystalline compound and a leveling agent, and is usually composed of a composition for forming a retardation layer or a cured product thereof.
The composition for forming a retardation layer contains a liquid crystal compound and a leveling agent, and usually further contains a solvent. Further, other components may be included as long as the alignment of the liquid crystal compound is not inhibited.
Since a liquid crystalline compound generally has a large refractive index anisotropy, it is easy to impart a desired retardation to a retardation film.

  Examples of the liquid crystal compound include a nematic liquid crystal compound, a cholesteric liquid crystal compound, a chiral nematic liquid crystal compound, a smectic liquid crystal compound, and a discotic liquid crystal compound. Moreover, what has a polymerizable functional group in a liquid crystal molecule is used suitably. If it has a polymerizable functional group, the stability of the retardation film is improved because the liquid crystalline compound can be cross-linked by the action of radicals generated from the photopolymerization initiator by irradiation of light or electron beam. To do.

  In the present invention, it is preferable to use a liquid crystalline compound having a phase transition temperature of 40 to 115 ° C., and a liquid crystalline compound having a temperature of 60 to 90 ° C. It is more preferable to use In the present invention, the phase transition temperature of the liquid crystal compound refers to a temperature at which the liquid crystal compound changes from a so-called liquid crystal phase having optical anisotropy to an isotropic phase having no optical anisotropy.

  Specific examples of the liquid crystalline compound used in the present invention include compounds represented by the following formulas (1) to (17).

  In the present invention, the liquid crystalline compounds can be used singly or in combination of two or more.

The phase difference layer forming composition contains a leveling agent. Thereby, the surface smoothness of a phase difference layer improves and generation | occurrence | production of the nonuniformity in a phase difference film is suppressed. As the leveling agent, a known leveling agent used for a retardation film can be appropriately selected and used, and is not particularly limited. For example, a fluorine-based nonionic surfactant, a special acrylic resin-based leveling agent, silicone Among them, silicone leveling agents such as fluorine-based nonionic surfactants and polyether-modified polysiloxane copolymers are preferable because they are excellent in achieving both the retardation characteristics of the retardation layer and the suppression of unevenness.
Examples of the fluorine-based nonionic surfactant include a nonionic compound having at least one selected from a perfluoroalkyl group and a perfluoroalkenyl group in the molecule. Examples of commercially available fluorine-based nonionic surfactants include Megafac F-444 (manufactured by DIC Corporation), Footage 215M, 251 and FTX-218 (manufactured by Neos Corporation).
Examples of commercially available silicone leveling agents include Polyflow KL-400X, Polyflow KL-400HF, Polyflow KL-401, Polyflow KL-402, Polyflow KL-403, Polyflow KL-404, Polyflow KL-100, and Polyflow KL. -700 (manufactured by Kyoeisha Chemical Co., Ltd.), TEGO (registered trademark) Flow425, TEGO (registered trademark) Glide series (manufactured by Evonik Tego Chemie) and the like.

  The composition for forming a retardation layer usually further contains a solvent. The solvent used in the composition for forming a retardation layer does not react with each component used in the composition for forming a retardation layer, and can be appropriately selected from solvents that can dissolve or disperse each component. . Specifically, it can be the same as the solvent used in the alignment layer forming composition.

  Moreover, the composition for forming the retardation layer may further contain other components as necessary. Examples of other components include a polymerization initiator, a polymerization inhibitor, a plasticizer, and a silane coupling agent.

  What is necessary is just to adjust suitably content of the said liquid crystalline compound in the composition for phase difference layer formation in the range which does not impair applicability | paintability. Especially, it is preferable that the content rate of the liquid crystalline compound with respect to the said whole composition for phase difference layer formation exists in the range of 5 mass%-40 mass%, and it exists in the range of 10 mass%-30 mass%. More preferred.

The amount of the leveling agent added to the retardation layer forming composition is generally 5 to 50,000 ppm, preferably from 5 to 50,000 ppm in the retardation layer forming composition from the viewpoint of improving the surface smoothness of the retardation layer. It is the quantity which becomes 10-20,000 ppm.
In addition, the content of the leveling agent in the total solid content of the composition for forming a retardation layer is 0.05% by mass or more and 0.3% by mass from the viewpoint that a retardation layer with favorable adhesive properties can be easily obtained. % Is preferable, and 0.1 to 0.2% by mass is more preferable. In addition, in this invention, solid content represents all the components except a solvent.

  What is necessary is just to determine the thickness of a phase difference layer suitably according to the kind etc. of the said liquid crystalline compound so that a desired in-plane retardation value may be obtained. Especially, it is preferable that it exists in the range of 0.5 micrometer-4 micrometers, it is more preferable in the range of 1 micrometer-3 micrometers, and it is further more preferable in the range of 1 micrometer-2 micrometers.

  The surface of the retardation film of the retardation film is subjected to easy adhesion treatment such as corona treatment, plasma treatment, low-pressure UV treatment, saponification treatment, or a method of forming an anchor layer in order to improve adhesion. be able to. Of these, a corona treatment, a method of forming an anchor layer, and a method of using these in combination are preferable.

  In addition, the retardation film used in the present invention includes functional layers such as a hard coat layer, an antiglare layer, an antireflection layer, and an antistatic layer in addition to the transparent substrate, the alignment layer, and the retardation layer. May be provided. Although the said functional layer is not specifically limited, For example, it can provide in the surface on the opposite side to the side in which the orientation layer of a transparent base material exists.

(Method for producing retardation film)
The method for producing the retardation film is not particularly limited as long as it is a method for obtaining the retardation film in which the alignment layer and the retardation layer are provided in this order on one surface side of the transparent substrate. A known method for producing a retardation film can be used.
Below, an example of the manufacturing method of the retardation film using the said elongate transparent base material is demonstrated as a method excellent in the mass-productivity of a retardation film.

  The method for producing a retardation film using the long transparent substrate includes, for example, a long transparent substrate preparation step, an alignment layer forming step, and a retardation layer forming step of preparing a long transparent substrate. It may have another process as needed.

First, a long transparent base material is prepared by a long transparent base material preparation step.
Next, an alignment layer is formed on one side of the long transparent substrate by an alignment layer forming step. The alignment layer forming step includes a step of coating the alignment layer forming composition on the long transparent substrate, a step of drying the coating film of the alignment layer forming composition, if necessary, and an alignment layer forming step. Other steps such as a step of curing the composition for forming and a step of shaping the composition for forming an alignment layer may be included.

  The coating method of the alignment layer forming composition in the alignment layer forming step may be any method as long as the alignment layer forming composition can be uniformly applied. What is necessary is just to select suitably from. For example, gravure coating method, reverse coating method, knife coating method, dip coating method, spray coating method, air knife coating method, spin coating method, roll coating method, printing method, dip pulling method, curtain coating method, die coating method, casting Various coating mechanisms used in the method, the bar coating method, the extrusion coating method, the E-type coating method and the like can be mentioned.

In this invention, the said composition for alignment layer formation can be continuously coated by conveying the said elongate transparent base material continuously to the said coating mechanism.
As the method for transporting the long transparent base material, a conventionally known method capable of continuously transporting the long base material may be appropriately selected and used. Specifically, for example, in a roll-to-roll method using a winder that continuously feeds a long transparent base material in a roll shape, and a winder that winds the long transparent base material, Examples thereof include a belt conveyor, a roll for conveyance, and a method of using various conveyance mechanisms such as a floating conveyance table that conveys a long transparent base material in a state where the long transparent base material is floated by discharging and sucking air.

The alignment layer forming step may further include a drying step for removing the solvent.
The coating film drying process may be performed using a known drying mechanism such as a heat drying mechanism, a reduced pressure drying mechanism, a gap drying mechanism, etc., and the drying temperature, drying time, and solvent atmosphere of the drying zone are adjusted to each drying mechanism. What is necessary is just to adjust a density | concentration etc. suitably. From the viewpoint of drying the coating film continuously and uniformly, it is preferably performed in combination with the transport mechanism.

In the case of using the photoalignable composition as the composition for forming an alignment layer, it usually has a polarization exposure step of exposing polarized light in order to express the alignment regulating power. The polarization exposure process is usually performed after the drying process. In the case of forming a patterned alignment layer, for example, the first polarized ultraviolet ray is irradiated to the coating film of the alignment layer forming ink containing the photoalignable material through a mask having a desired pattern. Then, a polarized light exposure step of forming an alignment layer imparted with an alignment regulating force in a pattern by irradiating the second polarized ultraviolet light having a polarization axis different from the polarization axis of the first polarized ultraviolet light without passing through a mask It is good. As such a polarization exposure process, for example, a method described in JP 2012-14064 A can be used. As a polarization exposure apparatus used in the polarization exposure process, a conventionally known apparatus may be appropriately selected and used. When a patterned alignment layer is formed, for example, as described in JP-A-2012-14064 An apparatus can be used.
The polarized light exposure step is preferably used in combination with the transport mechanism.

  Moreover, when using the said composition for shaping | molding as a composition for alignment layer formation, in order to express orientation control power, it has a shaping | molding process which provides a fine uneven | corrugated shape normally. The shaping process is usually performed after the coating process and before the drying process. As a specific example of the shaping step, for example, the fine uneven shape is formed by pressing the alignment layer original plate on which the fine uneven shape is formed on the coating film of the ultraviolet forming composition and irradiating with ultraviolet rays. And a method for forming an alignment layer. As a shaping apparatus used in the shaping step, a conventionally known exposure apparatus may be appropriately selected and used. In addition, as the alignment layer original plate, a conventionally known one may be appropriately selected and used. When a pattern retardation film is produced, an alignment layer original plate in which fine irregularities are formed in a desired pattern is used. That's fine.

(Retardation layer forming process)
The retardation layer forming step is a step in which the retardation layer forming composition is applied onto the alignment layer formed in the alignment layer forming step to continuously form the retardation layer.
The method for applying the retardation layer forming composition may be any method that can accurately apply a retardation layer having a desired thickness, and the same method as the method for applying the alignment layer forming resin composition; can do.

Next, in order to remove the solvent while aligning the liquid crystal compound in the composition for forming a retardation layer in a specific direction, it usually has a drying step.
The drying step is preferably heat drying from the viewpoint of aligning the liquid crystalline compound in the retardation layer-forming coating film. The heating temperature varies depending on the liquid crystal compound used, but is preferably 0 to 10 ° C. higher than the phase transition temperature of the liquid crystal compound.

  In the case of using a retardation layer forming ink containing a liquid crystalline compound having a photopolymerizable functional group, it may have an exposure step of irradiating the retardation layer forming coating film with ultraviolet rays or the like. The exposure process is usually performed after the drying process. Since the liquid crystalline compound can be crosslinked by the exposure step, the stability of the retardation film is improved. As the exposure apparatus used in the above exposure process, a conventionally known exposure apparatus may be appropriately selected and used, and examples thereof include an ultraviolet irradiation apparatus.

  Moreover, in the manufacturing method of the retardation film of this invention, you may have another process further as needed. For example, the method for producing the retardation film may include a step of forming the functional layer on the side opposite to the alignment layer of the transparent substrate before the alignment layer forming step.

(2) Measurement step The measurement step is a step of measuring the surface free energy of the retardation layer surface of the retardation film. As a method for measuring the surface free energy on the surface of the retardation layer, three components constituting the surface free energy, that is, a dispersion component (d), a polar component (p), and a hydrogen bonding component (h) can be measured. The method is not particularly limited, and a known measurement method can be used. For example, the three components of the surface free energy can be calculated by an extended Fowkes equation using a liquid whose surface free energy is known, measuring the contact angle of the surface of the retardation layer with an automatic contact angle meter.

  In the measurement step, the temperature at which the surface free energy is measured is preferably such that the temperature difference from the temperature at the time of applying the adhesive is within 5 ° C., for example, a temperature selected from the range of 20 to 25 ° C. Can be done.

(3) Evaluation Step The evaluation step is a step of evaluating whether or not the suitability of the adhesive on the surface of the retardation layer is allowed based on the result of the dispersion component (d) of the surface free energy measurement. As described in detail in the determination step of the manufacturing method described later, when the measurement result of the surface free energy dispersion component (d) on the retardation layer surface is 28 mN / m or more, the suitability of the adhesive on the retardation layer surface Is determined to be acceptable.
The evaluation method of the present invention can also be applied to a pattern-aligned phase difference film.

[Method for producing retardation film with polarizer]
In the method for producing a retardation film with a polarizer according to the present invention, an alignment layer and a retardation layer are provided in this order on one side of a transparent substrate, and the retardation layer contains a liquid crystalline compound and a leveling agent. A step of preparing a formed retardation film (hereinafter sometimes simply referred to as a preparation step);
A step of measuring the surface free energy of the surface of the retardation layer of the retardation film (hereinafter sometimes simply referred to as a measurement step);
A determination step of determining that the suitability of the adhesive on the surface of the retardation layer is allowed when the measurement result of the dispersion component (d) of the surface free energy is 28 mN / m or more;
In the determination step, a step of laminating a polarizer after applying the adhesive composition on the retardation layer that has been determined to have acceptable adhesive properties (hereinafter sometimes simply referred to as a polarizer lamination step). It is characterized by having.

  FIG. 2 is a schematic cross-sectional view showing an example of a retardation film with a polarizer obtained by the production method according to the present invention. A retardation film 20 with a polarizer shown in FIG. 2 has an alignment layer 2 and a retardation layer 3 provided in this order on the transparent substrate 1, and an adhesive layer on the retardation layer 3 of the retardation film 10. A polarizer 5 is provided via 4. The retardation film with a polarizer according to the present invention may further include other layers as required in addition to the retardation film, the adhesive layer, and the polarizer.

  According to the production method of the present invention, the surface free energy of the surface of the retardation film of the retardation film is measured, and the retardation film in which the suitability of the adhesive is allowed by the determination step is used. While using a retardation film having a retardation layer, a retardation film with a polarizer is produced, in which the defects of the adhesive layer due to the repellency of the adhesive used to attach the retardation film and the polarizer are suppressed. be able to. Therefore, a retardation film with a polarizer having good quality in which unevenness derived from the retardation layer and unevenness derived from the adhesive layer are suppressed can be obtained.

  The method for producing a retardation film with a polarizer according to the present invention includes (1) a preparation step, (2) a measurement step, (3) a determination step, and (4) a polarizer lamination step, and is necessary. Depending on the case, other steps may be included. In the manufacturing method according to the present invention, the (1) preparation step and (2) measurement step are steps common to the evaluation method according to the present invention, and are the same as described above. .

(3) Determination process The determination process is performed when the measurement result of the dispersion component (d) of the surface free energy on the surface of the retardation layer measured in the measurement process is 28 mN / m or more. It is a step of determining that the drug suitability is acceptable.
The ease of wetting and spreading of the adhesive to the surface of the retardation layer of the retardation film used in the present invention is estimated to affect the size of the dispersed component (d) among the components of the surface free energy. In the case where the dispersion component (d) is 28 mN / m or more, it is considered that the adhesive is particularly easily spread and the repelling is suppressed.
Further, although not particularly limited, the dispersion component (d) of the surface free energy on the surface of the retardation layer that is determined to be acceptable for the adhesive on the surface of the retardation layer in the determination step is 50 mN / m or less. It is preferable that it is 40 mN / m or less, and more preferable from the viewpoint of good adhesiveness because there is little difference in surface tension between the materials.

  Further, in the determination step, the measurement result of the sum of the polar component (p) and the hydrogen bond component (h) of the surface free energy on the surface of the retardation layer that allows the adhesive suitability, that is, the non-dispersed component is From the viewpoint of further suppressing repellency, it is preferably 5 mN / m or less, and more preferably 4 mN / m or less. In addition, the measurement result of the non-dispersed component is not particularly limited on the surface of the retardation layer where the adhesive suitability is allowed, but is usually 0.1 mN / m or more.

Further, in the determination step, the sum of the three components (A) of the surface free energy of the surface of the retardation layer in which the suitability of the adhesive is allowed, and the sum of the three components (B) of the surface energy of the adhesive composition. Satisfying the relationship of A> B is preferable from the viewpoint of further suppressing the repellency of the adhesive.
Here, the three components of the surface energy of the adhesive composition are determined by measuring the contact angle between the solid material having a known surface free energy calculated by the extended Fowkes equation and the adhesive composition, It can be calculated from Newmann's empirical formula.

(4) Polarizer Laminating Step The polarizer laminating step is a step of laminating a polarizer after applying an adhesive composition on the retardation layer determined to have acceptable adhesive properties in the determination step. is there.

As the adhesive composition, a known adhesive composition used for attaching a polarizer and a retardation film can be used, and is not particularly limited. For example, (meth) acrylate adhesive, polyvinyl alcohol Examples thereof include an adhesive based on urethane, an adhesive based on urethane, and an aqueous boron compound solution. As the adhesive composition, a (meth) acrylate adhesive and a polyvinyl alcohol adhesive are particularly preferable. Moreover, as said adhesive composition, it is preferable to contain especially 5-40 mass% of 2-hydroxyethylmethacrylate (HEMA), and it is more preferable to contain 10-30 mass%.
Moreover, the said adhesive composition can contain a solvent, an additive, etc. further as needed.

The adhesive layer can be formed by applying the adhesive composition and drying it as necessary.
As the coating method, a known method can be used. For example, the same method as the coating method of the composition for forming an alignment layer can be mentioned.
The drying conditions are appropriately selected according to the type of the adhesive composition, and are not particularly limited. For example, the drying conditions may be 80 to 100 ° C. for 1 to 5 minutes.

  Although the thickness of the said adhesive bond layer is not specifically limited, Usually, it is preferable that it is 0.01-100 micrometers, More preferably, it is 0.1-50 micrometers. When the thickness of the adhesive layer is equal to or higher than the lower limit value, the adhesive property is excellent and the adhesive repellency is less likely to occur, and when the thickness is equal to or lower than the upper limit value, the retardation film with a polarizer can be thinned. It is possible to cope with it, and the cost is also reduced.

  In the present invention, the polarizer can be appropriately selected from conventionally known polarizers. For example, a polyvinyl alcohol film, a polyvinyl formal film, a polyvinyl acetal film, an ethylene-vinyl acetate copolymer saponified film, which is dyed with iodine or a dye and stretched can be used.

  The polarizer is laminated after applying the adhesive composition on the retardation layer determined to have acceptable adhesive properties in the determination step. When the adhesive composition is dried when forming the adhesive layer, the polarizer may be laminated before the adhesive composition is dried, or the adhesive composition may be dried. You may laminate after making it. Especially, it is preferable to laminate | stack the said polarizer after drying the said adhesive composition from the point that generation | occurrence | production of the fault of the adhesive bond layer by the repellency of an adhesive composition is suppressed more.

Hereinafter, the present invention will be specifically described with reference to examples. These descriptions do not limit the present invention.
(Production Example 1: Production of pattern retardation film 1)
On one side of a transparent substrate (material acrylic, thickness 40 μm, size 210 mm × 297 mm), an alignment layer forming composition containing a polymer having cinnamate, which is a photodimerization reaction type photoalignment material, is applied and dried. To make a coating film.
The coating film was irradiated with the first polarized ultraviolet light through a mask having a stripe pattern with a width of 523 μm. Next, an alignment layer having a stripe pattern having a thickness of 150 nm is formed by irradiating the second polarized ultraviolet light having a polarization axis of 90 ° with the polarization axis of the first polarized ultraviolet light without passing through a mask. did.
Next, on the alignment layer, the following retardation layer forming composition 1 was applied and cured by irradiating with ultraviolet rays to form a retardation layer having a thickness of 1 μm. Thereafter, the surface of the retardation layer was subjected to corona treatment under the condition of 0.1 kW × 1 m / min to obtain a patterned retardation film 1.
<Preparation of retardation layer forming composition 1>
By diluting a liquid crystalline compound having a polymerizable functional group to a solid content of 25% by mass with methyl ethyl ketone, and adding a fluorine-based nonionic surfactant at a ratio of 0.1% by mass with respect to the total solid content, A composition 1 for forming a retardation layer was produced.

(Production Examples 2 to 5: Production of pattern retardation films 2 to 6)
In Production Example 1, in place of the retardation layer forming composition 1, except that the following retardation layer forming compositions 2 to 6 were used, respectively, in the same manner as in Production Example 1, the pattern retardation film 2. 6 was obtained.
<Preparation of retardation layer forming composition 2>
A liquid crystalline compound having a polymerizable functional group is diluted with methyl ethyl ketone to a solid content of 25% by mass, and a polyflow KL700 manufactured by Kyoeisha Chemical Co., Ltd. is used as a leveling agent at a ratio of 0.2% by mass with respect to the total solid content. By adding, the composition 2 for forming a retardation layer was produced.

<Preparation of retardation layer forming composition 3>
A liquid crystalline compound having a polymerizable functional group is diluted with methyl ethyl ketone to a solid content of 25% by mass, and there is added 0.2% by mass of Megafac F444 manufactured by DIC Corporation as a leveling agent to the total solid content. By adding, the composition 3 for forming a retardation layer was produced.

<Preparation of composition 4 for forming retardation layer>
A liquid crystalline compound having a polymerizable functional group is diluted with methyl ethyl ketone to a solid content of 25% by mass, and Flow 425 made by Evonik Tego Chemie is added as a leveling agent at a ratio of 0.2% by mass to the total solid content. Thus, a retardation layer forming composition 4 was produced.

<Preparation of retardation layer forming composition 5>
A liquid crystalline compound having a polymerizable functional group is diluted with methyl ethyl ketone to a solid content of 25% by mass, and 0.2% by mass of Glide 450 made by Evonik Tego Chemie is added as a leveling agent to the total solid content. Thus, a retardation layer forming composition 5 was produced.

<Preparation of retardation layer forming composition 6>
A liquid crystalline compound having a polymerizable functional group is diluted with methyl ethyl ketone to a solid content of 25% by mass, and the same fluorine-based compound as the retardation layer forming composition 1 at a ratio of 0.3% by mass with respect to the total solid content. By adding a nonionic surfactant, a retardation layer forming composition 6 was produced.

[Example 1]
The surface free energy of the surface of the retardation layer of the pattern retardation film 1 obtained above was measured by the following method. That is, the contact angles of water, diiodomethane and 1-bromonaphthalene on the surface of the retardation layer of the pattern retardation film were measured at 23 ° C. with an automatic contact angle meter (model number DM501, manufactured by Kyowa Interface Chemical Co., Ltd.) Each component of free energy was calculated using an extended Fowkes equation with analysis software (FAMAS). The calculation results are shown in Table 1.

An adhesive composition containing 20% by mass of 2-hydroxyethyl methacrylate (HEMA) was applied to the surface of the retardation layer of the pattern retardation film 1 so that the thickness after drying was 1 μm. Under the present circumstances, the surface (10 cm x 10 cm) which apply | coated the adhesive composition was observed visually, and the number of repellencies was counted. The results are shown in Table 1.
A retardation film with a polarizer of Example 1 was obtained by laminating a polarizer on the coating film of the adhesive composition. In the obtained retardation film with a polarizer, the defects of the adhesive layer due to the repellency of the adhesive were suppressed.

[Example 2]
In Example 1, it replaced with the pattern phase difference film 1, and obtained the phase difference film with a polarizer of Example 2 like Example 1 except having used the pattern phase difference film 2. FIG.
In the obtained retardation film with a polarizer, the defects of the adhesive layer due to the repellency of the adhesive were suppressed.

[Example 3]
In Example 1, it replaced with the pattern phase difference film 1, and obtained the phase difference film with a polarizer of Example 3 like Example 1 except having used the pattern phase difference film 3. FIG.
In the obtained retardation film with a polarizer, the defects of the adhesive layer due to the repellency of the adhesive were suppressed.

[Example 4]
In Example 1, it replaced with the pattern phase difference film 1, and obtained the phase difference film with a polarizer of Example 4 like Example 1 except having used the pattern phase difference film 4. FIG.
In the obtained retardation film with a polarizer, the defects of the adhesive layer due to the repellency of the adhesive were suppressed.

[Example 5]
In Example 1, it replaced with the pattern phase difference film 1, and obtained the phase difference film with a polarizer of Example 5 like Example 1 except having used the pattern phase difference film 5. FIG.
In the obtained retardation film with a polarizer, the defects of the adhesive layer due to the repellency of the adhesive were suppressed.

[Comparative Example 1]
In Example 1, it replaced with the pattern phase difference film 1, and obtained the phase difference film with a polarizer of the comparative example 1 like Example 1 except having used the pattern phase difference film 6. FIG.
The obtained retardation film with a polarizer had a defect of the adhesive layer due to the repellency of the adhesive, and was uneven.

Moreover, the surface free energy of the adhesive composition used in each Example and each Comparative Example was measured by the following method. That is, in Example 1, after the adhesive composition was applied and dried, the contact angles of water, diiodomethane and 1-bromonaphthalene were measured on the surface of the coating film of the adhesive composition using an automatic contact angle meter (Kyowa). It was measured at 23 ° C. using a model number DM501 manufactured by Interface Chemical Co., Ltd., and each component of the surface free energy was calculated using an extended Fowkes equation with analysis software (FAMAS).
As a result, the total of the three components (dispersion component (d), polar component (p), hydrogen bonding component (h)) of the surface free energy of the adhesive layer was 29.5.
Therefore, the relationship between the sum of the three components of the surface free energy on the surface of the retardation layer (A) and the sum of the three components of the surface free energy of the adhesive composition (B) is as follows. > B.

In the pattern retardation films 1 to 5 used in Examples 1 to 5, the measurement result of the dispersion component (d) of the surface free energy is 28 mN / m or more, and the number of repellency when the adhesive composition is applied is 0. It was a piece. On the other hand, the pattern retardation film 6 used in Comparative Example 1 has a measurement result of the surface free energy dispersion component (d) of less than 28 mN / m, and the number of repellants when the adhesive composition is applied is ten. That was all. Therefore, it can be seen that when the measurement result of the dispersion component (d) is 28 mN / m or more, it can be determined that the adhesive suitability of the surface of the retardation layer is allowed. Based on the result of the dispersion component (d), the retardation The suitability of the adhesive on the surface of the layer could be easily evaluated without applying an adhesive.
In Examples 1 to 5, since the measurement result of the surface free energy dispersion component (d) on the surface of the retardation layer was 28 mN / m or more, it was determined that the suitability of the adhesive on the surface of the retardation layer was allowed. In the obtained retardation film with a polarizer, defects of the adhesive layer due to the repellency of the adhesive were suppressed.

DESCRIPTION OF SYMBOLS 1 Transparent base material 2 Orientation layer 3 Retardation layer 4 Adhesive layer 5 Polarizer 10 Retardation film 20 Retardation film with a polarizer

Claims (2)

A method for producing a retardation film with a polarizer, comprising a polarizer laminated via an adhesive on a retardation film,
A step of preparing a retardation film in which an alignment layer and a retardation layer are provided in this order on one surface side of a transparent substrate, and the retardation layer contains a liquid crystal compound and a leveling agent;
Measuring the surface free energy of the retardation layer surface of the retardation film;
When the measurement result of the dispersion component (d) of the surface free energy is 28 mN / m or more and 40 mN / m or less, and the measurement result of the non-dispersion component of the surface free energy is 5 mN / m or less, the phase difference A determination step for determining that the adhesiveness of the surface of the layer is acceptable;
A phase difference with a polarizer, comprising: a step of laminating a polarizer after applying an adhesive composition on a phase difference layer that is determined to have acceptable adhesive properties in the determination step. A method for producing a film. A step of preparing a retardation film in which an alignment layer and a retardation layer are provided in this order on one surface side of a transparent substrate, and the retardation layer contains a liquid crystal compound and a leveling agent;
Measuring the surface free energy of the retardation layer surface of the retardation film;
Based on the results of the dispersion component (d) and the non-dispersion component in the measurement of the surface free energy, the measurement result of the dispersion component (d) of the surface free energy is 28 mN / m or more and 40 mN / m or less, When the measurement result of the non-dispersion component of the free energy is 5 mN / m or less, the adhesive suitability on the retardation layer surface is allowed and whether the adhesive suitability on the retardation layer surface is allowed or not. And a step of evaluating the phase difference film evaluation method.