JP2015148745A - Transfer laminate for optical film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transfer laminate for an optical film capable of suppressing a transfer failure even when a peeling speed of a support substrate is in a high speed region in the process of producing an optical film by using the transfer laminate for an optical film having a transfer layer.SOLUTION: A transfer laminate 1 for an optical film includes a transfer layer, and comprises a support substrate 11 made of polyethylene terephthalate (PET) not subjected to an easy adhesion treatment on the surface thereof, an alignment layer 12, and a retardation layer 13, layered in this order. The alignment layer 12 comprises an alignment layer composition containing 0.025 mass% or more and 0.1 mass% or less of a surfactant containing fluorine.

Description

  The present invention relates to an optical film transfer laminate having a transfer layer.

  In recent years, an optical film applied to a flat panel display or the like has been provided that ensures a desired optical characteristic by imparting a desired retardation to transmitted light by a retardation layer (see, for example, Patent Document 1). . In this type of optical film, an alignment film is prepared on the surface of a substrate made of a transparent film or the like, and cured in a state where the liquid crystal material is aligned by the alignment regulating force of the alignment film, thereby forming a retardation layer. A liquid crystal material applied to such a retardation layer usually has a positive wavelength dispersion characteristic, but recently, a liquid crystal material having a reverse dispersion characteristic has been proposed (see, for example, Patent Documents 2 and 3). . Here, the reverse dispersion characteristic is a wavelength dispersion characteristic in which the phase difference in the transmitted light is smaller toward the shorter wavelength side, and more specifically, retardation at a wavelength of 450 nm (R450) and retardation at a wavelength of 550 nm (R550). The relationship is R450 <R550.

  In addition, in the image display panel, a method for improving various optical characteristics such as viewing angle characteristics and color using an A plate, a C plate, etc. has been proposed. A device for optical compensation of an ISP liquid crystal display device using a C plate has been proposed. Here, the optical compensation is a configuration that reduces light leakage in an oblique direction from the linear polarizing plate during black display. The C plate is represented by nx = ny <nz or nx = ny> nz, where nx = ny <nz is a positive C plate and nx = ny> nz is a negative C plate. The A plate is represented by nx> ny = nz or nz = nx> ny, where nx> ny = nz is a positive A plate and nz = nx> ny is a negative A plate. Note that nx and ny (nx ≧ ny) are refractive indexes in the in-plane direction, and nz is a refractive index in the thickness direction.

  Among these optical films, the positive A plate uses a liquid crystal material with a positive wavelength dispersion characteristic and a liquid crystal material with a reverse dispersion characteristic applied to the retardation layer, respectively, and has a positive wavelength dispersion characteristic and a reverse dispersion characteristic, respectively. Can be produced. Further, a positive C plate can be produced by applying a coating liquid made of a liquid crystal material for a so-called C plate and drying and curing it. In vertical alignment (VA) liquid crystal display devices and the like, a liquid crystal material is aligned in the vertical direction by a vertical alignment film, and various devices for the vertical alignment film for VA liquid crystal have been proposed.

  Now, such an optical film is produced by, for example, a transfer method using a transfer laminate for an optical film having a transfer layer transferred to an optical functional layer such as a linearly polarizing plate that functions as a linearly polarizing plate. The In the transfer method, for example, when a desired layer is formed on a predetermined base material, the desired layer is not directly formed on the base material, but once a releasable support (support After the layer is formed in a peelable manner on the body substrate), a transfer laminate is produced, and then the layer formed on the support is finally laminated according to the process, demand, etc. In this method, a desired layer is formed on a predetermined base material by bonding and laminating on the (transfer base material) and then peeling and removing the support. It is considered that an optical film having a small overall thickness can be provided by producing an optical film by such a transfer method. In addition, the optical film produced by the transfer method is described in patent document 5 and patent document 6, for example.

  However, as described above, when the optical film is produced by transfer, when the transfer laminate is transferred onto the transfer target, the transfer laminate is not separated at the end of the portion to be transferred. There is a case where a so-called tearing (transfer defect) occurs in which an excessive transfer laminate portion remains on the transfer laminate side. In particular, when an optical film is produced with high productivity, when the peel strength of the support substrate is in a high-speed region, the problem of transfer failure has become prominent.

JP-A-10-68816 U.S. Pat. No. 8,119,026 Japanese translation of PCT publication No. 2010-52892 JP-T 2006-520008 JP 2005-49865 A JP 2007-156234 A

  The present invention has been proposed in view of such circumstances, and when an optical film is produced using a transfer laminate for an optical film having a transfer layer, the peeling speed of the support substrate is high. It is an object of the present invention to provide a transfer laminate for an optical film that can suppress the occurrence of transfer failure even in a region.

  This inventor repeated earnest examination in order to solve the subject mentioned above. As a result, in the transfer laminate for optical films, the alignment film laminated on the support substrate is supported by curing an alignment film composition containing a fluorine-containing surfactant at a predetermined ratio. The present inventors have found that the peel strength when the body substrate is peeled at a high speed can be weakened, and the occurrence of transfer failure of the transfer laminate can be effectively suppressed, and the present invention has been completed. That is, the present invention provides the following.

  (1) The present invention is a transfer laminate for an optical film having a transfer layer, wherein a support substrate made of polyethylene terephthalate whose surface is not corona-treated, an alignment film, and a retardation layer are arranged in this order. The alignment film is made of an alignment film composition containing a fluorine-containing surfactant at a ratio of 0.025% by mass or more and 0.1% by mass or less. It is a laminate.

  (2) Further, the present invention is the transfer laminate for an optical film according to the invention of (1), wherein fluorine is present at the interface between the support substrate and the alignment film.

  (3) The present invention is also characterized in that, in the invention of (1) or (2), the peel strength when the support substrate is peeled at a peeling speed of 50 m / min is 0.35 N / 50 mm or less. It is a transfer laminated body for optical films.

  (4) Further, the present invention is the transfer laminate for an optical film according to any one of (1) to (3), wherein the alignment film is composed of a vertical alignment film.

  (5) Further, in the invention according to any one of (1) to (4), the transfer layer is transferred to an optical functional layer that imparts a phase difference corresponding to a quarter wavelength composed of a reverse dispersion stretched film. A transfer laminate for optical films.

  According to the transfer laminate for an optical film of the present invention, the peel strength when the support substrate is peeled at a high speed can be weakened, and the occurrence of transfer failure with respect to the transfer target can be effectively suppressed.

It is a cross-sectional schematic diagram which shows an example of the transfer laminated body for optical films. It is a flowchart which shows the flow of the production process of the transfer laminated body for optical films. It is a figure for demonstrating the flow which produces an optical film by the transfer method using the transfer laminated body for optical films. It is a graph which shows a result when measuring about the peeling strength when changing the peeling rate of a PET base material about the transfer laminated body for optical films of Examples 1-3 and Comparative Example 1. FIG.

Hereinafter, specific embodiments of the transfer laminate for optical films according to the present invention (hereinafter referred to as “this embodiment”) will be described in detail in the following order. In addition, this invention is not limited to the following embodiment, A various change is possible in the range which does not change the summary of this invention.
1. 1. Configuration of optical film transfer laminate 2. Alignment film 3. Method for producing transfer laminate for optical film Method for producing optical film using transfer laminate for optical film

<< 1. Configuration of transfer laminate for optical film >>
FIG. 1 is a cross-sectional view schematically showing an example of a transfer laminate 1 for an optical film according to the present embodiment. As shown in FIG. 1, a transfer laminate 1 for an optical film has a support substrate 11 made of polyethylene terephthalate (PET), an alignment film 12, and a retardation layer (liquid crystal layer) 13 laminated in this order. It will be.

  The optical film transfer laminate 1 is transferred to, for example, an optical functional layer of a linearly polarizing plate, an optical functional layer that imparts a phase difference corresponding to a quarter wavelength to transmitted light, and the like. This is a transfer laminate for an optical film having a transfer layer, that is, a transfer layer including a retardation layer 13 and an alignment film 12. In this optical film transfer laminate 1, for example, a polymer film such as a reverse dispersion stretched film is bonded onto the retardation layer 13 via an adhesive to transfer the transfer layer, and a linear polarizing plate is further bonded. By combining them, a predetermined optical film can be produced. At this time, in producing the optical film, after transferring the transfer layer to a substrate such as a reverse dispersion stretched film on the optical film transfer laminate 1, only the support substrate having releasability is peeled off.

  In the transfer laminate 1 for an optical film according to the present embodiment, the alignment film 12 laminated on the support substrate 11 cures the alignment film composition containing a fluorine-containing surfactant at a predetermined ratio. It is characterized by being comprised by the hardened | cured material made to make.

  In such an optical film transfer laminate 1, the fluorine contained in the surfactant in the alignment film composition is present on the interface side of the alignment film 12 with the support substrate 11. Then, it becomes possible to weaken the peel strength of the support substrate 11, more specifically, the peel strength when the support substrate 11 is peeled at a high speed. Thereby, even when the support substrate 11 is peeled off at a high speed, it is possible to effectively suppress the occurrence of transfer failure of the transfer laminate with respect to the transfer target, and manufacture an optical film with high productivity. can do.

<1-1. Support base material>
The support substrate 11 is a film material made of polyethylene terephthalate (PET), which has a function of indicating the alignment film 12 and is formed in a long shape.

  The support substrate 11 functions as a releasable support in the optical film transfer laminate 1 and supports the alignment film 12 and the retardation layer 13 forming the transfer layer, and corona discharge on the surface thereof. A known easy adhesion treatment such as a treatment or a plasma treatment is not performed, and it has an adhesive force that can be peeled off from the alignment film 12.

  Although it does not specifically limit as thickness of the support base material 11, For example, it is preferable to set it as the range of 20 micrometers-200 micrometers. If the thickness of the support substrate 11 is less than 20 μm, it may not be possible to provide the minimum necessary self-supporting property as a transfer laminate for an optical film. On the other hand, when the thickness exceeds 200 μm, when the optical film transfer laminate is long, the long optical film transfer laminate is cut to obtain a single wafer optical film transfer laminate. In this case, it is not preferable because processing waste increases and wear of the cutting blade is accelerated.

<1-2. Alignment film>
The alignment film 12 is obtained by coating and curing the alignment film composition (alignment film composition) on the support substrate 11 described above, and exhibits an alignment regulating force. Here, the alignment regulating force is a function of arranging (orienting) the liquid crystal compound in a predetermined direction when a layer (retardation layer 13) made of a polymerizable liquid crystal compound (liquid crystal material) is formed on the alignment film 12. Say. The alignment film 12 can be formed by, for example, a photo-alignment method in which a photo-alignment material that exhibits photo-alignment properties by irradiation with polarized light is used and alignment is performed by light irradiation.

  The alignment film 12 is not particularly limited. For example, the alignment film 12 can be formed of a vertical alignment film that homeotropically aligns the molecular axes of the liquid crystal compound molecules in the retardation layer 13 (vertical alignment). As this vertical alignment film, various vertical alignment films applied to a VA liquid crystal display device or the like can be applied. For example, a polyimide alignment film, an alignment film made of an LB film, or the like can be applied.

  More specifically, as the vertical alignment film, for example, lecithin, silane-based surfactant, titanate-based surfactant, pyridinium salt-based polymer surfactant, and silane coupling-based vertical alignment such as n-octadecyltriethoxysilane. Composition for film, soluble polyimide having long chain alkyl group or alicyclic structure in side chain, composition for polyimide vertical alignment film such as polyamic acid having long chain alkyl group or alicyclic structure in side chain, etc. It can be formed using a material. In addition, as a composition for vertical alignment films, a composition for a polyimide-based vertical alignment film “JALS-2021” and “JALS-204” manufactured by JSR Co., Ltd., and “RN-1517” manufactured by Nissan Chemical Industries, Ltd. , "SE-1211", "EXPOA-018" and other commercial products can be applied.

  The solvent (dilution solvent) used in the alignment film composition is not particularly limited as long as it can dissolve the alignment material at a desired concentration. For example, hydrocarbon solvents such as benzene and hexane, methyl ethyl ketone, Ketone solvents such as methyl isobutyl ketone and cyclohexanone (CHN), ether solvents such as tetrahydrofuran, 1,2-dimethoxyethane, propylene glycol monoethyl ether (PGME), alkyl halide solvents such as chloroform and dichloromethane, methyl acetate Ester solvents such as ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate (PGMEA), amide solvents such as N, N-dimethylformamide, sulfoxide solvents such as dimethyl sulfoxide, anan solvents such as cyclohexane, Methanol, ethanol, isopropyl alcohol (hereinafter, referred to as. "IPA") can be exemplified an alcohol solvent such as. Moreover, one type of solvent may be sufficient and the mixed solvent of two or more types of solvents may be sufficient.

  Such an alignment film 12 made of a vertical alignment film or the like is produced by applying a coating liquid made of an alignment film composition containing the material as described above to the support substrate 11, drying, and heating. The The alignment film 12 is composed of the cured product thus produced.

  Here, in the transfer laminate 1 for an optical film according to the present embodiment, the alignment film 12 includes an alignment film composition containing a fluorine-containing surfactant (fluorine-containing surfactant) at a predetermined ratio. It is characterized by becoming. Specifically, it is comprised by the orientation film composition which contains a fluorine-containing surfactant in the composition in the ratio of 0.025 mass% or more and 0.1 mass% or less.

  As will be described in detail later, according to the transfer laminate 1 for an optical film having such an alignment film 12, the peeling strength of the support substrate 11, specifically, when the support substrate 11 is peeled at high speed. Even when the support substrate 11 is peeled off at a high speed in order to increase productivity, it is possible to suppress the occurrence of transfer failure of the transfer laminate to the transfer target. Can do.

<1-3. Retardation layer (liquid crystal layer)>
The retardation layer (liquid crystal layer) 13 contains a polymerizable liquid crystal composition. This polymerizable liquid crystal composition contains a liquid crystal compound (rod-like compound) exhibiting liquid crystallinity and having a polymerizable functional group in the molecule.

  The liquid crystal compound has refractive index anisotropy and has a function of imparting a desired retardation by regularly arranging the liquid crystal compound. Examples of the liquid crystal compound include materials exhibiting a liquid crystal phase such as a nematic phase and a smectic phase, but the nematic phase is easier in order to arrange regularly than liquid crystal compounds exhibiting other liquid crystal phases. It is preferable to use a material exhibiting the above liquid crystallinity. The liquid crystal compound exhibiting a nematic phase is preferably a material having spacers at both ends of the mesogen. Since the liquid crystal compound having spacers at both ends of the mesogen is excellent in flexibility, it is possible to make the transfer laminate 1 for an optical film excellent in transparency.

  In addition, when the alignment film 12 described above is made of a vertical alignment film and the liquid crystal compound is homeotropically aligned, there is no particular limitation as long as it is a homeotropic liquid crystal material capable of forming homeotropic alignment. Examples of the homeotropic liquid crystal material include materials that can form homeotropic alignment without using a vertical alignment film, and materials that can form homeotropic alignment by using a vertical alignment film. In the present embodiment, either can be suitably used.

  The liquid crystal compound is a polymerizable liquid crystal compound having a polymerizable functional group in the molecule as described above. By having a polymerizable functional group, it is possible to polymerize and fix the liquid crystal compound, so that the alignment stability is excellent and the phase change is less likely to occur over time. The polymerizable liquid crystal compound more preferably has a polymerizable functional group capable of three-dimensional crosslinking in the molecule. By having a polymerizable functional group capable of three-dimensional crosslinking, the sequence stability can be further enhanced. Note that “three-dimensional crosslinking” means that liquid crystal molecules are polymerized three-dimensionally to form a network structure.

  Examples of the polymerizable functional group include those that polymerize by the action of ionizing radiation such as ultraviolet rays and electron beams, or heat. Examples of these polymerizable functional groups include radical polymerizable functional groups and cationic polymerizable functional groups. Representative examples of radically polymerizable functional groups include functional groups having at least one addition-polymerizable ethylenically unsaturated double bond, such as vinyl groups having or without substituents, acrylate groups (acryloyl). Group, methacryloyl group, acryloyloxy group, generic name including methacryloyloxy group) and the like. Moreover, an epoxy group etc. are mentioned as a specific example of a cationically polymerizable functional group. In addition, examples of the polymerizable functional group include an isocyanate group and an unsaturated triple bond. Among them, a functional group having an ethylenically unsaturated double bond is preferably used from the viewpoint of the process.

  The amount of the polymerizable liquid crystal compound is not particularly limited as long as the viscosity of the retardation layer forming coating liquid (liquid crystal composition) can be adjusted to a desired value according to the coating method applied on the alignment film 12. Although it does not specifically limit, For example, it can be in the range of about 5-40 mass parts as a quantity in a liquid-crystal composition. In addition, a polymeric liquid crystal compound can be used individually by 1 type or in mixture of 2 or more types.

  The liquid crystal compound described above is usually dissolved in a solvent (dilution solvent). The solvent is not particularly limited as long as it can uniformly disperse liquid crystal compounds and the like. For example, hydrocarbon solvents such as benzene and hexane, ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone (CHN). Solvent, ether solvents such as tetrahydrofuran, 1,2-dimethoxyethane, propylene glycol monoethyl ether (PGME), halogenated alkyl solvents such as chloroform and dichloromethane, methyl acetate, ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate Ester solvents such as (PGMEA), amide solvents such as N, N-dimethylformamide, sulfoxide solvents such as dimethyl sulfoxide, anone solvents such as cyclohexane, methanol, ethanol, isopropyl It can be exemplified an alcohol solvent such as alcohol, but is not limited thereto. Further, the solvent may be one kind or a mixed solvent of two or more kinds of solvents.

  The amount of the solvent is not particularly limited and can be, for example, about 66 to 900 parts by mass with respect to 100 parts by mass of the liquid crystal compound. If the amount of the solvent is less than 66 parts by mass, the liquid crystal compound may not be dissolved uniformly, which is not preferable. On the other hand, when the amount exceeds 900 parts by mass, a part of the solvent remains, which may reduce reliability and may not be uniformly applied.

  In addition, the liquid crystal composition may contain other compounds as necessary, as long as the alignment order of the liquid crystal compounds described above is not impaired. Examples thereof include a polymerization inhibitor, a plasticizer, a surfactant, and a silane coupling agent.

  The thickness of the retardation layer 13 formed by coating the liquid crystal composition as described above on the alignment film 12 is not particularly limited. The thickness is preferably about 2000 nm.

≪2. About alignment film >>
As described above, in the transfer laminate 1 for an optical film according to the present embodiment, the alignment film 12 is composed of an alignment film composition containing a fluorine-containing surfactant at a predetermined ratio. Yes. Specifically, it is comprised by the orientation film composition which contains a fluorine-containing surfactant in the ratio of 0.025 mass% or more and 0.1 mass% or less.

  In the transfer laminate 1 for an optical film having the alignment film 12 formed of the alignment film composition containing the fluorine-containing surfactant at a predetermined ratio, the interface between the support substrate 11 and the alignment film 12 is provided. , Fluorine will be present. The fluorine present at the interface between the support substrate 11 and the alignment film 12 is derived from fluorine contained in the surfactant in the alignment film composition. Here, more fluorine derived from the surfactant bleeds out to the atmosphere side (comparably hydrophobic) than to the support substrate 11 side, which is relatively hydrophilic. However, since a small amount of fluorine that could not be bleed out to the atmosphere side is more stable when it moves to the support substrate 11 side than in the alignment film 12, the support substrate 11 is thereby stabilized. It is presumed that fluorine exists at the interface between the alignment layer 12 and the alignment film 12.

  Thus, in the transfer laminate 1 for an optical film in which fluorine is present at the interface between the support substrate 11 and the alignment film 12, when the interface between the support substrate 11 and the alignment film 12 is the peeling interface, The peel strength of the support substrate 11, more specifically, the peel strength when the support substrate 11 is peeled at a high speed can be weakened. Thereby, for example, even when the support substrate 11 is peeled off at a high speed in order to increase productivity, it is possible to effectively suppress the occurrence of transfer failure (crying separation) of the transfer laminate with respect to the transfer target. it can.

  For example, when the peeling speed is lower than about 30 m / min, the peeling strength does not change as compared with the conventional transfer laminate, but when the peeling speed is higher than that, the alignment film 12 containing the fluorine-containing surfactant is used. In the optical film transfer laminate 1 having the above, the peel strength can be effectively reduced. More specifically, for example, when the peeling speed is 50 m / min, the peeling strength is 0.350 [N / 50 mm] or less.

  As shown in detail in the following examples, when the transfer laminate of the comparative example (conventional) sample (no surfactant) was used, the peel strength at a peel speed of 50 m / min was approximately 0.425. Whereas [N / 50 mm], in the transfer laminate for optical film 1 (Example), the peel strength at the same peel speed of 50 m / min was 0.350 [N / 50 mm] or less, and thus for optical films. It can be seen that the peel strength can be greatly reduced by using the transfer laminate 1.

  This is because the effect of significantly reducing the peel strength appears as the film is peeled at a high speed. For example, even when the support substrate 11 is peeled off at a high speed in order to increase productivity, Occurrence of transfer defects in the transfer laminate can be effectively suppressed.

  In addition, by including a fluorine-containing surfactant in the alignment film composition as described above, it becomes possible to exhibit excellent uniform coating properties (leveling properties), and the formed alignment film 12 can be made smoother. It can be made.

  The fluorine-containing surfactant to be contained in the alignment film 12 is not particularly limited as long as it is a fluorine-containing surfactant, and may be any of cationic, anionic, amphoteric, and nonionic.

  For example, examples of the cationic fluorosurfactant include perfluoroalkyltrimethylammonium salts such as perfluoroalkyltrimethylammonium iodide. Examples of the anionic fluorosurfactant include perfluoroalkyl sulfonates such as ammonium perfluoroalkyl sulfonate, potassium perfluoroalkyl sulfonate, sodium perfluoroalkyl sulfonate, and perfluoroalkyl carboxylic acid. Perfluoroalkylcarboxylates such as ammonium acid salt, potassium perfluoroalkylcarboxylate, sodium perfluoroalkylcarboxylate, perfluoroalkylnaphthalenesulfonate, perfluoroalkylbenzenesulfonate, perfluoroalkyldiallylsulfonate And perfluoroalkyl phosphate esters. Examples of amphoteric fluorine-based surfactants include perfluoroalkylamino sulfonates (perfluoroalkyl betaines). Examples of nonionic fluorosurfactants include perfluoroalkylethylene oxide adducts, perfluoroalkyl esters, perfluoroalkyl group / hydrophilic group-containing oligomers, perfluoroalkyl group / lipophilic group-containing oligomers, Examples include perfluoroalkyl group-containing oligomers, perfluoroalkyl group / lipophilic group-containing urethanes, perfluoroalkyl oligomers, perfluoroalkylamine oxides, ethylene oxide adducts of perfluoroalkyl group-containing silicones, and the like.

  As described above, the content of the fluorine-containing surfactant is set to a ratio of 0.025% by mass or more and 0.1% by mass or less. If the content is less than 0.025% by mass, the peel strength when peeling at high speed cannot be effectively reduced, and transfer defects cannot be effectively suppressed.

  On the other hand, if the content exceeds 0.1% by mass, an effect of weakening the peeling strength at the time of high-speed peeling can be obtained, but a large amount of fluorine is included in the alignment film 12, so that on the alignment film 12 When the coating liquid for forming the retardation layer containing the liquid crystal composition is applied, the coating liquid cannot be uniformly applied onto the alignment film 12 and the alignment film 12 is exposed. Generate repellency. As a result, adhesion failure with the retardation layer 13 occurs, the phase difference of the part where the repellency occurs is reduced, causing defects and the like, leading to poor appearance, and also causing a decrease in yield. Become.

≪3. Manufacturing method of transfer laminate for optical film >>
Next, the manufacturing method of the transfer laminated body for optical films is demonstrated. FIG. 2 is a flowchart showing the flow of the manufacturing process of the optical film transfer laminate 1. In the following description of the manufacturing method, the case where the alignment film 12 is formed of a vertical alignment film will be described as an example, but the present invention is not limited thereto.

  As shown in FIG. 2, in the production of the optical film transfer laminate 1, first, a support substrate 11 made of a PET film is provided from a long film wound around a roll (S1).

  Next, in the alignment film forming step (S2), a coating liquid (alignment film composition) for the vertical alignment film is applied onto the support substrate 11 fed from the roll, and is thermally cured using a dryer or the like. Apply processing. As a result, a vertical alignment film is produced on the support substrate 11 and the alignment film 12 is formed. At this time, in the present embodiment, an alignment film composition containing a fluorine-containing surfactant at a ratio of 0.025% by mass or more and 0.1% by mass or less is coated on the support substrate 11. Thus, the alignment film 12 is formed.

  Next, in the retardation layer forming step (S3), a liquid crystal composition coating liquid containing a liquid crystal compound (a retardation layer forming coating liquid) is applied onto the alignment film 12. Thereafter, the retardation layer (liquid crystal layer) 13 is formed by drying and curing by irradiation with ultraviolet rays or the like. In addition, you may make it perform the leveling process for making the layer thickness of the phase difference layer 13 uniform before an ultraviolet irradiation process.

  Here, in the present embodiment, as described above, the alignment film composition containing the fluorine-containing surfactant at a ratio of 0.025 mass% or more and 0.1 mass% or less is formed on the support substrate 11. The alignment film 12 is formed by coating. In such an alignment film 12, fluorine derived from the surfactant is present at the interface between the support substrate 11 and the alignment film 12, and thus the support substrate 11 is peeled off at high speed. The peel strength can be weakened. Thereby, even if it is a case where the support base material 11 is peeled at high speed in order to improve productivity, generation | occurrence | production of the transfer defect of the transfer laminated body with respect to a to-be-transferred body can be suppressed effectively.

  Thus, after manufacturing the laminated body film by which the support base material 11 / alignment film 12 / retardation layer 13 are laminated | stacked in this order, after winding up the obtained film with a winding reel etc., desired The cutting process is performed to cut out to the size. Through such steps, the optical film transfer laminate 1 is produced.

  The coating method of the alignment film composition on the support substrate 11 and the coating method of the retardation layer forming coating liquid on the alignment film 12 are not particularly limited. For example, , Die coating method, 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, dipping and lifting method, curtain coating method, casting method , Bar coating method, extrusion coating method, E-type coating method and the like can be used.

<< 4. Production method of optical film using transfer laminate for optical film >>
Next, a method for producing an optical film by the transfer method using the above-described optical film transfer laminate will be described. FIG. 3 shows an optical film transfer to an optical functional layer made of a reverse dispersion stretched film and imparting a phase difference of ¼ wavelength to transmitted light using the optical film transfer laminate 1 according to the present embodiment. It is a figure which shows the flow of the process at the time of transferring the transfer layer of the laminated body 1, and producing an optical film. In addition, this FIG. 3 is a figure which shows the cross section of a film, and is a figure which shows the flow of a process, showing the layer structure of the film in each process. Further, the layer structure of the film is not limited to this.

  First, as shown in FIG. 3A, an alignment film 12 made of, for example, a vertical alignment film is formed on a support substrate 11 (release base) made of a PET film, and the alignment film 12 is formed on the alignment film 12. A phase difference layer (liquid phase layer) 13 is formed by applying a phase difference layer forming coating solution containing a liquid crystal composition to produce a transfer laminate 1 for an optical film. Here, as described above, in the production of the transfer laminate 1 for an optical film, an alignment film composition containing a fluorine-containing surfactant at a ratio of 0.025% by mass to 0.1% by mass is used. Thus, the alignment film 12 is configured.

  Next, as shown in FIG. 3B, an adhesive layer 21 containing, for example, a UV adhesive is formed on the retardation layer 13 of the produced optical film transfer laminate 1. Then, a polymer film (protective film) 22 is formed, and the optical film transfer laminate 1 is transferred.

  Various adhesives such as an ultraviolet curable resin, a thermosetting resin, and a pressure sensitive adhesive can be widely applied as the adhesive layer 21. Among them, ultraviolet (UV) is used from the viewpoint of reducing the overall thickness. It is preferable to apply a curable resin to form a UV adhesive layer. In this case, an adhesive layer having a thickness of about 1 μm can be produced. An adhesive layer may be applied to the adhesive layer 21.

  The polymer film is not particularly limited, and for example, a stretched film having reverse dispersion characteristics (hereinafter also referred to as “reverse dispersion stretched film 22”) can be used. The reverse dispersion stretched film 22 is formed of, for example, a COP (cycloolefin polymer) film that is stretched in one axial direction or obliquely stretched in a desired direction, and the slow axis is relative to the absorption axis of the linearly polarizing plate. Thus, it is arranged to form an angle of θ2 degrees counterclockwise, and plays a role as a retardation layer for a quarter wavelength plate that imparts a phase difference of a quarter wavelength to transmitted light. By using such a reverse dispersion stretched film 22, for example, the configuration of the base material, the resin layer for a quarter wavelength plate, and the alignment film for a quarter wavelength plate can be omitted. The layer thickness can be reduced.

  When a polymer film 22 such as a reverse dispersion stretched film is laminated on the transfer laminate 1 for an optical film and transferred, next, as shown in FIG. 3 (c), a support substrate for the transfer laminate 1 for an optical film 11 is peeled off. The optical film transfer laminate 1 thus serves as a releasable support in order to transfer the transfer layer (retardation layer 13 and alignment film 12) to another substrate (polymer film or the like) in this way. The supporting substrate 11 to be carried is peeled off. In addition, you may make it perform peeling of the support body base material 11 after laminating | stacking the linear polarizing plate mentioned later.

  And if the support base material 11 of the transfer laminated body 1 for optical films is peeled, next, as shown in FIG.3 (d), the linearly-polarizing plate provided with the adhesive layer 31 will be laminated | stacked.

  As the linear polarizing plate, the optical functional layer is disposed after the lower surface side of the base material 34 made of a transparent film such as TAC (triacetyl cellulose) is saponified. In addition, the base material 34 is poly (meth) methyl acrylate, poly (meth) butyl acrylate, (meth) methyl acrylate- (meth) butyl acrylate copolymer, (meth) methyl acrylate-styrene copolymer. Resins such as acrylic resin such as coalescence, glass such as soda glass, potassium glass, lead glass, and quartz glass can also be applied.

  The optical functional layer is a part responsible for the optical function as a linear polarizing plate, and for example, a layer in which a polarizer 33 and a transparent protective film (base material) 32 made of an acrylic resin or the like are sequentially laminated are used. Can do. Such a linearly polarizing plate is bonded to a polymer film 22 such as a reverse dispersion stretched film via an adhesive layer 31.

  Based on the above processes, an optical film can be produced by a transfer method using the optical film transfer laminate 1. In particular, in the present embodiment, a fluorine-containing surfactant is included in the alignment film 12 of the optical film transfer laminate 1, so that the fluorine is formed between the support substrate 11 and the alignment film 12. It comes to exist in an interface, and the peeling strength when peeling the support base material 11 at high speed can be weakened. Thereby, generation | occurrence | production of the transfer defect of the transfer laminated body with respect to a to-be-transferred body can be suppressed effectively, and productivity can be improved.

  As described above, the optical film transfer laminate 1 has the alignment film 12 made of a vertical alignment film, and is reversely disposed on the retardation layer 13 of the optical film transfer laminate 1 via the adhesive layer 21. A dispersion-stretched film 22 is laminated, and a linearly polarizing plate provided with a polarizer 33 sandwiched between base materials 32, 34 made of a transparent film is provided on the reverse dispersion-stretched film 22, so that high productivity can be achieved easily. Therefore, an optical film having a positive C plate with reverse dispersion characteristics can be obtained.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the following examples.

<Examples and Comparative Examples>
[Example 1]
(Preparation of transfer laminate for optical film)
Using a PET substrate (manufacturer name, product number) with a thickness of 38 μm that has not been easily peeled off such as corona discharge treatment, a vertical alignment film composition is coated on one side to a thickness of 3 μm, and 20 mJ / An alignment film was prepared by irradiating polarized ultraviolet rays of cm ² . Here, as the composition for the vertical alignment film, a fine cure PXV-18 manufactured by Sanyo Chemical Industries, Ltd. was used, and in the composition, a fluorine-containing surfactant (manufactured by DIC, MegaFac F- 554) was added at a rate of 0.025% by mass.

  Subsequently, a liquid crystal layer composition (RMM28B, manufactured by Merck Co., Ltd.) was applied on the formed alignment film by die coating to form a retardation layer (liquid crystal layer) having a thickness of about 1 μm. Thus, the transfer laminated body for optical films in which the base material (support base material), the alignment film, and the retardation layer were laminated in this order was produced.

(Transfer of transfer laminate for optical film)
Next, transfer using the reverse dispersion stretched film as a transfer medium was performed using the transfer laminate for an optical film obtained as described above. Specifically, first, an adhesive layer containing a UV adhesive is formed on the retardation layer of the obtained optical film transfer laminate, and a reverse dispersion stretched film made of a COP film is pasted on the adhesive layer. The transfer layer (retardation layer, alignment film) in the transfer laminate for optical films was transferred. And after bonding a reverse dispersion stretched film, the PET base material was peeled by making the interface of a PET base material and an oriented film into a peeling interface.

  In this example, the peeling strength [N / 50 mm] when the PET base material was peeled while changing the peeling speed was measured.

(XPS analysis of alignment film side surface after peeling PET substrate)
In Example 1, the transfer layer was transferred to the reverse dispersion stretched film using the transfer laminate for optical films, and elemental analysis was performed on the alignment film side surface of the transfer laminate after peeling off the PET substrate. This elemental analysis was performed by X-ray photoelectron spectroscopy (XPS) using an X-ray spectroscopic analyzer ESCALAB 220i-XL manufactured by Thermo Fisher Scientific. Table 1 below shows the XPS analysis results of the alignment film surface after the PET substrate was peeled.

  As shown in the analysis results of Table 1, 0.3 at% fluorine, which is a component contained in the surfactant, is present on the surface of the alignment film after peeling the PET substrate, that is, on the interface between the PET substrate and the alignment film. I found out that

[Example 2]
Except that the alignment film was prepared using a composition containing a fluorine-containing surfactant (manufactured by DIC, MegaFace F-554) at a ratio of 0.050% by mass as the composition for the vertical alignment film. In the same manner as in No. 1, a transfer laminate for an optical film was prepared, and subsequently, a transfer treatment was performed using the reverse dispersion stretched film as a transfer target. And also in the sample of this Example 2, peeling strength [N / 50mm] when changing the peeling speed and peeling the PET base material was measured.

[Example 3]
Except for preparing an alignment film using a composition containing a fluorine-containing surfactant (manufactured by DIC, Megafac F-554) at a ratio of 0.100% by mass as a composition for a vertical alignment film. In the same manner as in No. 1, a transfer laminate for an optical film was prepared, and subsequently, a transfer treatment was performed using the reverse dispersion stretched film as a transfer target. And also in the sample of this Example 3, peeling strength [N / 50mm] when changing the peeling speed and peeling the PET base material was measured.

[Comparative Example 1]
A transfer laminate for an optical film was prepared in the same manner as in Example 1 except that the fluorine-containing surfactant was not added as the composition for the vertical alignment film, and then the reverse dispersion stretched film was transferred to the transfer target. The transfer process was performed. And also in the sample of this comparative example 1, peeling strength [N / 50mm] when changing the peeling speed and peeling the PET substrate was measured.

<Result>
FIG. 4 shows the peel strength [N / of the laminate for optical film of Examples 1 to 3 and the laminate for optical film of Comparative Example 1 when the peel rate was changed and the PET substrate was peeled off. It is a graph which shows a result when measuring [50 mm].

  As can be seen from the graph of FIG. 4, for example, when the peeling speed is lower than about 30 m / min, there is no difference in the peeling strength between the transfer laminates. It turns out that the peeling strength becomes weak in the transfer laminated body for optical films of Examples 1 to 3 having an alignment film containing.

  Specifically, in the transfer laminate for an optical film of Comparative Example 1 to which no fluorine-containing surfactant was added, the peel strength when the PET substrate was peeled at a peel rate of 50 m / min was approximately 0.425 [N / 50 mm], in the transfer laminates for optical films of Examples 1 to 3 in which a predetermined amount of a fluorine-containing surfactant was added to form an alignment film, peeling at a peeling speed of 50 m / min. It turns out that intensity | strength becomes 0.350 [N / 50mm] or less, and has weakened effectively.

  And in such a transfer laminated body for optical films of Examples 1-3, it turns out that the effect of the fall of a peeling strength appears notably, so that peeling speed | velocity exceeds 30 m / min. From this, according to the transfer laminate for optical films as in Examples 1 to 3, for example, even when the support substrate is peeled off at a high speed in order to increase productivity, the transfer laminate on the transfer target It turns out that generation | occurrence | production of the transcription | transfer defect of a body can be suppressed effectively.

DESCRIPTION OF SYMBOLS 1 Transfer laminated body for optical films 11 Support base material 12 Alignment film 13 Retardation layer (liquid crystal layer)

Claims (5)

A transfer laminate for an optical film having a transfer layer,
A support substrate made of polyethylene terephthalate that has not been subjected to easy adhesion treatment on the surface, an alignment film, and a retardation layer are laminated in this order,
The said alignment film is comprised by the alignment film composition which contains the surfactant containing a fluorine in the ratio of 0.025 mass% or more and 0.1 mass% or less, The transfer laminated body for optical films characterized by the above-mentioned.   The transfer laminate for an optical film according to claim 1, wherein fluorine is present at an interface between the support substrate and the alignment film.   The transfer laminate for an optical film according to claim 1 or 2, wherein a peel strength when the support substrate is peeled at a peel speed of 50 m / min is 0.35 N / 50 mm or less.   The transfer laminate for an optical film according to any one of claims 1 to 3, wherein the alignment film is composed of a vertical alignment film. 5. The optical film according to claim 1, wherein the transfer layer is transferred to an optical functional layer made of a reverse dispersion stretched film and imparts a phase difference corresponding to ¼ wavelength. 6. Transfer laminate.

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