JP2007072032A - Optical anisotropic film and its manufacturing method, polarizing plate and liquid crystal display using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method by which an optical anisotropic film having proper optical compensation capability can be manufactured stably. <P>SOLUTION: The manufacturing method of the optical anisotropic film comprises a process of forming an optical anisotropic layer by applying an optical anisotropic layer forming composition, containing a mesomorphism compound which has at least one of polymerizable group and has isotropic phase transition temperature T°C on a support body and subjecting to drying and a hardening process of hardening the optical anisotropic layer, by irradiating the optical anisotropic layer with ultraviolet rays at least one time at a temperature range of 40°C and T°C and with ≤10 volume% of oxygen concentration. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optically anisotropic film useful as an optical compensation film, a polarizing plate, and a liquid crystal display device, and more specifically, an optical compensation film that contributes to an improvement in viewing angle characteristics of a vertical alignment (VA) mode liquid crystal display device, and The present invention relates to a polarizing plate and a vertical alignment (VA) mode liquid crystal display device having excellent viewing angle characteristics. The present invention also relates to a transfer material capable of easily transferring an optically anisotropic layer having optical compensation ability into and out of a liquid crystal cell.

  CRT (Cathode Ray Tube) has been mainly used as a display device used for OA devices such as word processors, notebook personal computers, personal computer monitors, portable terminals, and televisions. In recent years, liquid crystal display devices (LCDs) have been widely used instead of CRTs because of their thinness, light weight, and low power consumption. The liquid crystal display device has a liquid crystal cell and a polarizing plate. The polarizing plate is composed of a protective film and a polarizing film, and is obtained by dyeing a polarizing film made of a polyvinyl alcohol film with iodine, stretching, and laminating both surfaces with a protective film. For example, in a transmissive liquid crystal display device, the polarizing plate is attached to both sides of the liquid crystal cell, and one or more optical compensation films may be disposed. On the other hand, in a reflective liquid crystal display device, a reflector, a liquid crystal cell, one or more optical compensation films, and a polarizing plate are arranged in this order. The liquid crystal cell includes a liquid crystal molecule, two substrates for encapsulating the liquid crystal molecule, and an electrode layer for applying a voltage to the liquid crystal molecule. The liquid crystal cell performs ON / OFF display depending on the alignment state of liquid crystal molecules, and can be applied to any of a transmissive type, a reflective type, and a semi-transmissive type, such as TN (Twisted Nematic), IPS (In-Plane Switching), Display modes such as OCB (Optically Compensatory Bend), VA (Vertically Aligned), ECB (Electrically Controlled Birefringence), and STN (Super Twisted Nematic) are proposed. However, the color and contrast that can be displayed by a conventional liquid crystal display device vary depending on the angle at which the LCD is viewed. For this reason, the viewing angle characteristics of liquid crystal display devices have not yet exceeded the performance of CRT.

  In recent years, as an LCD method for improving the viewing angle characteristics, nematic liquid crystal molecules having negative dielectric anisotropy are used, and the major axis of the liquid crystal molecules is aligned in a direction substantially perpendicular to the substrate without applying a voltage. A vertical alignment nematic liquid crystal display device (hereinafter referred to as VA mode) in which this is driven by a thin film transistor has been proposed (see Patent Document 1). This VA mode not only has excellent display characteristics when viewed from the front, but also exhibits a wide viewing angle characteristic by applying a viewing angle compensation phase difference plate (optical compensation film). . In the VA mode, a wider viewing angle characteristic can be obtained by using a negative uniaxial retardation plate (negative c-plate) having an optical axis in a direction perpendicular to the film surface. It is also known that a wider viewing angle characteristic can be realized by using a uniaxially oriented retardation plate (positive a-plate) having a positive refractive index anisotropy having a retardation value of 50 nm ( Non-patent document 1).

  However, when the number of retardation plates is increased in this way, the production cost increases. In addition, since a large number of films are bonded together, it tends to cause not only a decrease in yield but also a deterioration in display quality due to a shift in the bonding angle. Furthermore, since a plurality of films are used, the thickness increases, which may be disadvantageous for thinning the display device.

  Moreover, although a stretched film is normally used for positive a-plate, when using the longitudinally stretched film in a continuous conveyance process, the slow axis of a-plate turns into the film conveyance (MD) direction. However, in the VA mode viewing angle compensation, the slow axis of the a-plate must be orthogonal to the MD direction which is the absorption axis of the polarizing plate. Rises significantly. As a method for solving this, it is possible to use a so-called laterally stretched film that is stretched in a direction orthogonal to MD (TD direction). However, the transversely stretched film is apt to cause distortion of a slow axis called bowing, and the yield is high. The cost increases because it does not increase. Furthermore, since an adhesive layer is used for lamination of stretched films, the adhesive layer contracts due to temperature and humidity changes, and defects such as peeling and warping between films may occur. As a method for improving these, a method of producing a-plate by applying a rod-like liquid crystal is known (see Patent Document 2).

  Furthermore, in recent years, a method using a biaxial retardation plate in place of the combination of c-plate and a-plate has been proposed (Non-Patent Document 2). By using a biaxial retardation plate, there is an advantage that not only the contrast viewing angle but also the color can be improved. However, the biaxial stretching usually used to produce a biaxial retardation plate is a lateral Similar to stretching, uniform axis control over the entire region of the film is difficult, and the yield does not increase, resulting in an increase in cost.

  Therefore, a biaxial retardation plate is produced without using stretching by a method of irradiating polarized violet light to a special cholesteric liquid crystal (Patent Document 3) or a method of irradiating a special disk-shaped liquid crystal to polarized ultraviolet light (Patent Document 4). A way to do it was proposed. By this method, various problems caused by stretching can be solved.

  In order to irradiate such polarized ultraviolet rays, it is necessary to use a polarizing filter having polarization separation characteristics in the ultraviolet region of 380 nm or less, but at least half of the polarized light component cannot be used due to the principle problem of polarizing filters. Compared with non-polarized light irradiation, the irradiation amount is small. In order to maintain high productivity, it is necessary to increase the conveyance speed, and the irradiation amount of polarized ultraviolet rays becomes smaller in inverse proportion to the conveyance speed.

  When the irradiation amount is small, the strength of the cured film is insufficient, a method of irradiating a special cholesteric liquid crystal with polarized ultraviolet light (Patent Document 3), or a method of irradiating a special disk-shaped liquid crystal with polarized ultraviolet light (Patent Document 4) Therefore, when it is accompanied by molecular orientation of the liquid crystal during curing, it also affects the molecular orientation and consequently the optical properties.

Regarding the ultraviolet curing reaction, Patent Document 5 describes that the hardness is increased by curing a photocurable resin at a low oxygen concentration. Patent Documents 6 to 11 describe specific means for nitrogen substitution. However, by irradiating polarized ultraviolet rays as in the optically anisotropic layer, if there is a relationship between the liquid crystal molecular alignment and curing of the optically anisotropic layer, it is necessary to sufficiently cure the film thickness uniformly. In order to sufficiently reduce the oxygen concentration, a large amount of nitrogen is required, resulting in an increase in manufacturing cost.
Japanese Patent Laid-Open No. 2-176625 JP 2000-304930 A EP1389199 A1 Japanese Patent Laid-Open No. 2002-6138 Japanese Patent Laid-Open No. 2002-156508 Japanese Patent Laid-Open No. 11-268240 JP 60-90762 A JP 59-112870 A JP-A-4-301456 Japanese Patent Laid-Open No. 3-67697 JP 2003-300215 A Japanese Patent Publication No. 7-51641 SID 97 DIGEST Pages 845-848 SID 2003 DIGEST, pages 1208-1211

  An object of the present invention is to provide a method capable of producing an optically anisotropic film useful as an optical compensation film having a good optical compensation function stably and with high productivity. Another object of the present invention is to provide an optical compensation film capable of accurately optically compensating a liquid crystal cell, and a polarizing plate using the same. Another object of the present invention is to provide a liquid crystal display device in which the liquid crystal cell is accurately optically compensated, particularly a VA mode liquid crystal display device. Another object of the present invention is to provide a transfer material capable of easily transferring an optically anisotropic layer for optical compensation into a liquid crystal cell or the like.

Means for solving the above problems are as follows.
[1] An optically anisotropic layer is formed by applying and drying a composition for forming an optically anisotropic layer containing a liquid crystalline compound having an isotropic phase transition temperature T ° C. having at least one polymerizable group on a support. Forming, and
A curing step of curing the optically anisotropic layer by irradiating the optically anisotropic layer with ultraviolet rays at least once at 40 ° C. or more and T ° C. or less and an oxygen concentration of 10% by volume or less. For producing a conductive film.
[2] The method according to [1], wherein in the curing step, the oxygen concentration at the time of ultraviolet irradiation is 3% by volume or less.
[3] The curing step is performed simultaneously or continuously with the transporting step of transporting the laminate having the optically anisotropic layer on the support in an atmosphere having an oxygen concentration of 10% by volume or less [1] or [ 2].
[4] The method according to [3], wherein in the transporting step, the laminate is transported in an atmosphere of 40 ° C. or higher and T ° C. or lower.
[5] In any of the above [1 to 4], in the curing step and / or the conveying step, an oxygen blocking gas heated to 40 ° C. or higher and T ° C. or lower is jetted to maintain the oxygen concentration in the atmosphere in the above range. That way.
[6] The method according to [5], wherein the oxygen blocking gas is an inert gas.
[7] The method according to any one of [1] to [6], wherein the ultraviolet ray is partially or entirely polarized.
[8] The method according to any one of [1] to [7], wherein the optically anisotropic layer after curing has a phase difference where the front retardation (Re) is not zero.

[9] An optically anisotropic film produced by any one of the methods [1] to [9].
[11] The optically anisotropic film of [10] used as an optical compensation film.
[12] A polarizing plate having a polarizing film and a pair of protective films protecting the polarizing film, wherein at least one of the pair of protective films is the optically anisotropic film of [10] or [11] Polarizer.
[13] A transfer material having a photosensitive resin layer on the optically anisotropic layer of the optically anisotropic film of any one of [1] to [10].
[14] A liquid crystal display device including a liquid crystal cell having a pair of substrates and a liquid crystal layer sandwiched therebetween, and further, the polarizing plate of [12] and / or the liquid crystal cell outside the liquid crystal cell. A liquid crystal display device having an optically anisotropic layer transferred from the transfer material of [13] on at least one surface of a pair of substrates.
[15] The liquid crystal display device according to [14], wherein the display mode is a VA mode.

  According to the present invention, it is possible to improve the adhesion of an optically anisotropic layer, which is a problem during rework of a polarizing plate protective film, and to produce an optical compensation film having excellent optical compensation characteristics. In addition, by using the optically anisotropic film of the present invention as an optical compensation film, it becomes possible to optically compensate a liquid crystal cell with the same configuration as a conventional liquid crystal display device. The liquid crystal display device of the present invention having an improved viewing angle as well as display quality. Furthermore, by using the transfer material of the present invention, a layer having optical compensation ability can be easily formed in the liquid crystal cell.

BEST MODE FOR CARRYING OUT THE INVENTION

  Hereinafter, the present invention will be described in detail. The description of the constituent elements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

  In the present invention, Re and Rth each represent a front retardation and a retardation in the thickness direction at a wavelength λ. Re is measured with KOBRA 21ADH (manufactured by Oji Scientific Instruments Co., Ltd.) by making light of wavelength λ nm incident in the normal direction of the film. Rth is Re, the slow axis in the plane (determined by KOBRA 21ADH) is used as the tilt axis (rotation axis), the angle is changed with respect to the normal direction of the film, and light of wavelength λ nm is incident from the tilted direction. KOBRA 21ADH is calculated based on a plurality of retardation values measured in this manner.

  In this specification, “substantially” for the angle means that the error from the exact angle is within a range of less than ± 5 °. Furthermore, the error from the exact angle is preferably less than 4 °, more preferably less than 3 °. With regard to retardation, “substantially” means that the retardation is within ± 5%. Furthermore, “Re is not 0” means that Re is 5 nm or more. In addition, the measurement wavelength of the refractive index indicates an arbitrary wavelength in the visible light region unless otherwise specified. In the present specification, “visible light” refers to light having a wavelength of 400 to 700 nm.

[Optical compensation film]
FIG. 1 is a schematic sectional view of an example of the optical compensation film of the present invention. The optical compensation film of the present invention has an optically anisotropic layer 12 on a transparent support 11. Between the transparent support 11 and the cured optically anisotropic layer 12, an alignment layer 13 for controlling the alignment of liquid crystalline molecules in the optically anisotropic layer 12 is disposed. The cured optically anisotropic layer 12 is formed on the alignment layer 13 provided on the transparent support while transporting the optically anisotropic layer-forming solution containing at least one liquid crystalline compound to the transparent support. The layer is coated and dried to form an optically anisotropic layer. The layer is irradiated with polarized ultraviolet rays at least once, and then further irradiated with non-polarized ultraviolet rays or polarized ultraviolet rays having no polarization plane at least once. Can be formed by curing. The alignment layer 13 can be formed from a polymer having a reactive group in the side chain, or a monomer or oligomer having a reactive group. In particular, if the reactive group of the alignment layer can react with the reactive group of the liquid crystalline compound used in the optically anisotropic layer, the adhesion between the optically anisotropic layer and the alignment layer is high, Peeling and the like hardly occur at the time of washing treatment such as water washing and chemical treatment such as saponification treatment, and the handleability is good. Further, the optical properties of the optically anisotropic layer 12 are such that the front retardation (Re) is not 0, and the in-plane slow axis is the tilt axis (rotation axis) and + 40 ° with respect to the normal direction of the optical compensation film. A retardation value measured by making light of wavelength λ nm incident from an inclined direction, and a direction inclined by −40 ° with respect to the normal direction of the optical compensation film with an in-plane slow axis as an inclination axis (rotation axis) Since the retardation value measured by making light having a wavelength λ nm incident is adjusted to be substantially equal, a liquid crystal cell, particularly a VA mode liquid crystal cell can be compensated accurately.

[Polarizer]
2A to 2D are schematic sectional views of a polarizing plate having the optical compensation film of the present invention. In general, the polarizing plate can be prepared by dyeing a polarizing film made of a polyvinyl alcohol film with iodine and performing stretching to obtain the polarizing film 21, and laminating protective films 22 and 23 on both sides thereof. it can. Since the optical compensation film of the present invention has a support made of a polymer film or the like that supports the optically anisotropic layer, this support can be used as it is for at least one of the protective films 22 and 23. At this time, even if the optically anisotropic layer 12 is disposed on the polarizing layer 21 side (that is, the optically anisotropic layer 12 is closer to the polarizing layer 21 than the support 11), the optically anisotropic layer 12 is on the opposite side of the polarizing layer 21 ( That is, the optically anisotropic layer 12 may be disposed farther from the support 11 than the polarizing layer 21, but as shown in FIG. 2A, the optically anisotropic layer 12 includes the polarizing layer 21. It is preferable that it exists in the other side. Further, as shown in FIG. 2 (b), it is also possible to bond to the outside of one protective film 22 of the polarizing layer 21 via an adhesive or the like.

  2C and 2D are configuration examples of a polarizing plate in which another functional layer 24 is further arranged on the polarizing plate having the configuration shown in FIG. FIG. 2C is a configuration example in which another functional layer 24 is disposed on the protective film 23 disposed on the opposite side with the optical compensation film of the present invention and the polarizing layer 21 in between. d) is a structural example in which another functional layer 24 is disposed on the optical compensation film of the present invention. Examples of other functional layers are not particularly limited, and examples thereof include functional layers that impart various characteristics, such as λ / 4 layers, antireflection layers, and hard coat layers. These layers may be bonded together with, for example, an adhesive as a member such as a λ / 4 plate, an antireflection film, or a hard coat film. In the configuration example of FIG. Another functional layer 24 may be formed on the film (the optically anisotropic layer 12) and then bonded to the polarizing layer 21 for production. Further, the protective film 23 on the side opposite to the optical compensation film of the present invention can be made into another functional film such as a λ / 4 plate, an antireflection film, a hard coat film.

  When producing a polarizing plate by laminating a polarizing film and a protective film, a total of three films of a pair of protective film and polarizing film are bonded together in a roll-to-roll manner. This roll-to-roll is a preferable method as a manufacturing process of a polarizing plate because it is difficult to cause dimensional change and curling of the polarizing plate as well as productivity, and can impart high mechanical stability.

[Transfer material]
The transfer material of the present invention has a support, at least one optically anisotropic layer, and at least one photosensitive resin layer, and the optically anisotropic layer and the photosensitive resin layer are disposed on another substrate. It is a material used to transfer to FIG. 3 is a schematic cross-sectional view of some examples of the transfer material of the present invention. The transfer material of the present invention shown in FIG. 3A has an optically anisotropic layer 12 and a photosensitive resin layer 14 on a transparent or opaque temporary support 11. The transfer material of the present invention may have other layers. For example, as shown in FIG. 3B, between the temporary support 11 and the optically anisotropic layer 12, there is a counter substrate at the time of transfer. It may have a layer 15 for controlling mechanical properties such as cushioning for absorbing unevenness on the side or imparting unevenness followability, and as shown in FIG. A layer 13 that functions as an alignment layer for controlling the alignment of the liquid crystal molecules in the crystalline layer 12 may be disposed, and may further include both layers as shown in FIG. . Moreover, you may provide the protective layer 16 which can peel in the outermost surface for the objectives, such as surface protection of the photosensitive resin layer of FIG.3 (e).

[Transfer substrate for liquid crystal display]
The transfer material of the present invention is transferred to a substrate for a liquid crystal display device and can constitute an optically anisotropic layer for compensating the viewing angle of the liquid crystal cell. Furthermore, an optically anisotropic layer for compensating the viewing angle of the liquid crystal cell can be formed for each of R, G, and B colors by combination with a color filter. The substrate to which such a layer is transferred may be used for either one of the pair of substrates of the liquid crystal cell, or may be used by being divided into both. FIG. 4A is a schematic cross-sectional view of an example of a substrate with an optically anisotropic layer produced by the transfer material of the present invention. The transfer substrate 30 is not particularly limited as long as it is transparent, but preferably has a small birefringence, and glass, a low birefringence polymer, or the like is used. An optically anisotropic layer 27 is formed on the substrate using the transfer material of the present invention, and a black matrix 29 and further a color filter layer 28 are formed thereon. Although omitted in FIG. 4A, a photosensitive resin layer that is a constituent layer in the transfer material is disposed between the optically anisotropic layer 27 and the substrate 30, and the optically anisotropic layer 27. And the substrate 30 are bonded via a photosensitive resin layer. A transparent electrode layer 25 is further formed on the color filter layer 28, and an alignment layer 26 for aligning liquid crystal molecules in the liquid crystal cell is formed thereon. After the optically anisotropic layer 27 is formed on the substrate 30 using the transfer material of the present invention, a resist is uniformly applied, and then the black matrix 22 and the color are formed by removing unnecessary portions by development after mask exposure. The filter layer 28 may be produced, or may be formed using a printing method or an ink jet method that has been proposed recently. The latter is preferable from the viewpoint of cost.

  FIG. 4B is a schematic cross-sectional view of an example of a substrate having a color filter with an optically anisotropic layer, which is manufactured using the transfer material of the present invention. The transfer substrate 30 is not particularly limited as long as it is a transparent substrate, but a substrate having small birefringence is desirable, and glass, a low birefringence polymer, or the like is used. A black matrix 29 is generally formed on the substrate, and a color filter layer 28 and an optically anisotropic layer 27 ′ composed of a photosensitive resin layer that is patterned by mask exposure or the like after being transferred from the transfer material of the present invention are formed thereon. Is formed. FIG. 4 shows an embodiment in which the color filter layers 28 of R, G, and B are formed, but as is often seen recently, a color filter layer composed of layers of R, G, B, and W (white) is formed. May be. The optically anisotropic layer 27 ′ is divided into r, g, and b regions, and has optimum retardation characteristics for the colors of the R, G, and B filter layers 28. Although there may be another layer transferred from the transfer material on the optically anisotropic layer 27 ', it is necessary to prevent impurities from entering the liquid crystal cell as much as possible. It is preferably removed during processing. A transparent electrode layer 25 is formed on the optically anisotropic layer 27 ', and an alignment layer 26 for aligning liquid crystal molecules in the liquid crystal cell is formed thereon.

  Further, using the transfer material of the present invention, as shown in FIG. 4C, the non-patterned solid optical anisotropic layer 27 and the patterned optical material are formed on one substrate using the transfer material of the present invention. Two anisotropic layers 27 ′ may be formed. Although not shown, an optical anisotropic layer 27 is formed by forming a solid optical anisotropic layer 27 on one of a pair of opposing substrates of a liquid crystal cell and patterning the other substrate using the transfer material of the present invention. The conductive layer 27 ′ may be formed together with the color filter layer 28. In many cases, a drive electrode such as a TFT array is generally disposed on one of the pair of counter substrates, and a solid optical anisotropic layer 27 may be formed on the drive electrode. An optically anisotropic layer 27 ′ patterned on the electrode may be formed together with the color filter layer 28. The optically anisotropic layer may be formed at any position on the substrate. However, in the case of an active drive type having a TFT, the optically anisotropic layer is formed above the silicon layer due to the heat resistance of the optically anisotropic layer. Is preferred.

  By using the transfer material of the present invention, a single color filter and an optically anisotropic layer corresponding to it can be formed simultaneously in one transfer-exposure-development process. The viewing angle characteristics of the liquid crystal display device can be improved with the same number of steps as in the case of the color filter manufacturing process described in the above.

[Liquid Crystal Display]
FIG. 5 is an example of a liquid crystal display device using the polarizing plate of the present invention. The liquid crystal display device includes a liquid crystal cell 55 having a nematic liquid crystal sandwiched between upper and lower electrode substrates, and a pair of polarizing plates 56 and 57 disposed on both sides of the liquid crystal cell. Uses the polarizing plate of the present invention shown in FIG. When using the polarizing plate of this invention, it can arrange | position so that an optically anisotropic layer may exist between a polarizing layer and the electrode substrate of a liquid crystal cell. Nematic liquid crystal molecules are controlled so as to be in a predetermined alignment state by providing an alignment layer applied on the electrode substrate and a structure such as a rubbing treatment or a rib on the surface thereof.

  One or more light control films 54 such as a brightness enhancement film and a diffusion film may be provided under the liquid crystal cell sandwiched between the polarizing plates. Furthermore, the light control film has a reflection plate 52 and a light guide plate 53 for irradiating light emitted from the cold cathode tube 51 to the front side. Instead of a backlight unit comprising a cold cathode tube and a light guide plate, recently, a direct type backlight in which several cold cathode tubes are arranged under a liquid crystal cell, an LED backlight using an LED as a light source, or an organic EL In addition, a backlight that emits surface light using inorganic EL or the like is also used, but the optical compensation film of the present invention is effective in any backlight.

  Furthermore, although not shown in the drawing, in the aspect of the reflective liquid crystal display device, only one polarizing plate needs to be disposed on the observation side, and a reflective film is provided on the back surface of the liquid crystal cell or on the inner surface of the lower substrate of the liquid crystal cell. . Of course, it is also possible to provide a front light using the light source on the liquid crystal cell observation side. Further, a transflective type in which a transmissive portion and a reflective portion are provided in one pixel of the display device is also possible.

  FIG. 6 is a schematic sectional view of an example of a liquid crystal display device using the transfer material of the present invention. 6 (a) to 6 (c) use the glass substrate of FIGS. 4 (a) to 4 (c) as an upper substrate, and a liquid crystal 31 with a liquid crystal 31 interposed therebetween with the glass substrate with TFT shown in 32 as an opposing substrate. This is a liquid crystal display device using the cell 37. On both sides of the liquid crystal cell 37, a polarizing plate 36 composed of a polarizing layer 33 sandwiched between two cellulose ester films 34 and 35 is disposed. As the cellulose ester film 35 on the liquid crystal cell side, an optical film that contributes to optical compensation may be used, or, like 34, only a function as a protective film may be used. Although not shown in the drawing, in the aspect of the reflective liquid crystal display device, only one polarizing plate is required on the observation side, and a reflective film is provided on the back surface of the liquid crystal cell or on the inner surface of the lower substrate of the liquid crystal cell. Of course, a front light can be provided on the liquid crystal cell observation side. Further, a transflective type in which a transmissive portion and a reflective portion are provided in one pixel of the display device is also possible. The display mode of the present liquid crystal display device is not particularly limited, and can be used for all transmissive and reflective liquid crystal display devices. In particular, the present invention is effective for the VA mode where color viewing angle characteristics are desired to be improved.

Next, materials used for production of the optical compensation film and transfer material of the present invention, production methods, and the like will be described in detail.
An example of the optical compensation film of the present invention has a transparent support, an alignment layer, and a cured optically anisotropic layer, and the optically anisotropic layer expands the contrast viewing angle of the liquid crystal display device. This contributes to eliminating the image coloring of the apparatus. The optical compensation film of the present invention is a liquid crystal display device in which the support of the optically anisotropic layer also serves as a protective film for a polarizing plate, or the optically anisotropic layer also serves as a protective film for a polarizing plate. The number of components can be reduced. In other words, such an embodiment contributes to the thinning of the liquid crystal display device.
Moreover, the transfer material of the present invention further comprises a photosensitive resin layer on the cured optical anisotropic layer of the optical anisotropic film having an optical anisotropic layer cured on the surface of a temporary support or the like. Have By using such a transfer material, for example, an optically anisotropic layer can be easily formed on the inner surface of the substrate of the liquid crystal cell. In addition, the optically anisotropic film before forming the photosensitive resin layer may have an optical characteristic that can be used as an optical compensation film, or may be a desired optical compensation film. The optical characteristics may not be exhibited (for example, the support is opaque).
Hereinafter, although the said aspect demonstrates in detail about the material used for preparation, a preparation method, etc., this invention is not limited to this aspect. Other embodiments can also be produced with reference to the following description and conventionally known methods. However, the present invention is not limited to the embodiments described below.

  In the present invention, an optically anisotropic layer containing a liquid crystalline compound is formed on an optically uniaxial or biaxial transparent support made of a high molecular polymer, thereby significantly improving the optical characteristics of the liquid crystal display device. be able to.

[Optically anisotropic layer]
In the present invention, the optically anisotropic layer contributes to optical compensation of the liquid crystal cell. Of course, the optically anisotropic layer alone may have sufficient optical compensation ability, or may be an aspect satisfying the optical characteristics required for optical compensation in combination with other layers (for example, a support). The cured optically anisotropic layer, for example, a coating liquid containing at least one liquid crystalline compound on an alignment layer provided on the transparent support while transporting the transparent support using a continuous transport process. After forming an optically anisotropic layer by coating and drying, the layer is irradiated with ultraviolet rays at least once under a predetermined condition described later while transporting a transparent support having the layer, and the layer Can be formed by curing.

  The liquid crystalline compound used for forming the optically anisotropic layer is not particularly limited. In general, liquid crystal compounds can be classified into a rod-shaped type and a disk-shaped type based on their shapes. In addition, there are low and high molecular types, respectively. Polymer generally refers to a polymer having a degree of polymerization of 100 or more (Polymer Physics / Phase Transition Dynamics, Masao Doi, 2 pages, Iwanami Shoten, 1992). In the present invention, any liquid crystalline compound can be used, but a rod-like liquid crystalline compound is preferably used from the viewpoint that in-plane retardation can be efficiently generated by irradiation with polarized ultraviolet rays. Two or more kinds of rod-like liquid crystalline compounds, two or more kinds of disc-like liquid crystalline compounds, or a mixture of a rod-like liquid crystalline compound and a disk-like liquid crystalline compound may be used. It is more preferable to use a rod-like liquid crystal compound or a discotic liquid crystal compound having a reactive group, since at least one of the reactive groups in one liquid crystal molecule can be formed. Is more preferably 2 or more. The liquid crystalline compound may be a mixture of two or more, and in that case, at least one preferably has two or more reactive groups. The thickness of the optically anisotropic layer is preferably 0.1 to 20 μm, and more preferably 0.5 to 10 μm.

  The discotic liquid crystalline compound used for forming the optically anisotropic layer in the optical compensation film of the present invention is not particularly limited, and known ones can be used. Examples of rod-like liquid crystalline compounds include azomethines, azoxys, cyanobiphenyls, cyanophenyl esters, benzoic acid esters, cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexanes, cyano-substituted phenylpyrimidines, alkoxy-substituted phenylpyrimidines. , Phenyldioxanes, tolanes and alkenylcyclohexylbenzonitriles are preferably used. Not only the above low-molecular liquid crystalline compounds but also high-molecular liquid crystalline compounds can be used. The polymer liquid crystalline compound is a polymer compound obtained by polymerizing a rod-like liquid crystalline compound having a low molecular reactive group. As the rod-like liquid crystalline compound having a low-molecular reactive group that is particularly preferably used, a rod-like liquid crystalline compound represented by the following general formula (I) can be exemplified.

Formula (I): Q ¹ -L ¹ -A ¹ -L ³ -ML ⁴ -A ² -L ² -Q ²
Wherein, Q ¹ and Q ² respectively represent a reactive group, the L ^1, L ^2, L ³ and L ⁴ respectively represent a single bond or a divalent linking group, L ³ and At least one of L ⁴ is preferably —O—CO—O—. A ¹ and A ² each independently represent a spacer group having 2 to 20 carbon atoms. M represents a mesogenic group.

Hereinafter, the rod-like liquid crystal compound having a reactive group represented by the general formula (I) will be described in more detail. In the formula, Q ¹ and Q ² are each independently a reactive group. The polymerization reaction of the reactive group is preferably addition polymerization (including ring-opening polymerization) or condensation polymerization. In other words, the reactive group is preferably a reactive group capable of an addition polymerization reaction or a condensation polymerization reaction. Examples of reactive groups are shown below.

Examples of the divalent linking group represented by L ¹ , L ² , L ³ and L ⁴ include —O—, —S—, —CO—, —NR ² —, —CO—O—, and —O—CO. —O—, —CO—NR ² —, —NR ² —CO—, —O—CO—, —O—CO—NR ² —, —NR ² —CO—O—, and NR ² —CO—NR ^2. A divalent linking group selected from the group consisting of-is preferred. R ² is an alkyl group having 1 to 7 carbon atoms or a hydrogen atom. In this case, at least one of L ³ and L ⁴ is —O—CO—O— (carbonate group). In the formula (I), Q ¹ -L ¹ and Q ² -L ² -are CH ₂ ═CH—CO—O—, CH ₂ ═C (CH ₃ ) —CO—O—, and CH ₂ ═C ( Cl) -CO-O-CO- O- are _{preferable, CH 2 = CH-CO-} O- is most preferable.

A ¹ and A ² represent a spacer group having 2 to 20 carbon atoms. An aliphatic group having 2 to 12 carbon atoms is preferable, and an alkylene group is particularly preferable. The spacer group is preferably chain-like and may contain oxygen atoms or sulfur atoms that are not adjacent to each other. The spacer group may have a substituent and may be substituted with a halogen atom (fluorine, chlorine, bromine), a cyano group, a methyl group, or an ethyl group.

Examples of the mesogenic group represented by M include all known mesogenic groups. In particular, a group represented by the following general formula (II) is preferable.
Formula (II): - (- W 1 -L 5) n-W 2 -
In the formula, W ¹ and W ² each independently represent a divalent cycloaliphatic group, a divalent aromatic group or a divalent heterocyclic group, L5 represents a single bond or a linking group, and a linking group Specific examples of these include specific examples of groups represented by L ^{1 to} L ⁴ in the formula (I), —CH ₂ —O—, and O—CH ₂ —. n represents 1, 2 or 3.

W ¹ and W ² include 1,4-cyclohexanediyl, 1,4-phenylene, pyrimidine-2,5-diyl, pyridine-2,5diyl, 1,3,4-thiadiazole-2,5-diyl, 1,3,4-oxadiazole-2,5-diyl, naphthalene-2,6-diyl, naphthalene-1,5-diyl, thiophene-2,5-diyl, pyridazine-3,6-diyl . In the case of 1,4-cyclohexanediyl, there are trans isomers and cis isomers, but either isomer may be used, and a mixture in any proportion may be used. More preferably, it is a trans form. W ¹ and W ² may each have a substituent. Examples of the substituent include a halogen atom (fluorine, chlorine, bromine, iodine), a cyano group, an alkyl group having 1 to 10 carbon atoms (methyl group, ethyl group, propyl group, etc.), and an alkoxy group having 1 to 10 carbon atoms. (Methoxy group, ethoxy group, etc.), C1-10 acyl group (formyl group, acetyl group, etc.), C1-10 alkoxycarbonyl group (methoxycarbonyl group, ethoxycarbonyl group, etc.), carbon atom Examples thereof include an acyloxy group having 1 to 10 (acetyloxy group, propionyloxy group, etc.), nitro group, trifluoromethyl group, difluoromethyl group and the like.

  Preferred examples of the basic skeleton of the mesogenic group represented by the general formula (II) are shown below. These may be substituted with the above substituents.

  Examples of the compound represented by the general formula (I) are shown below, but the present invention is not limited thereto. The compound represented by the general formula (I) can be synthesized by the method described in JP-T-11-513019.

  The optically anisotropic layer is preferably formed using an alignment layer and a gas-liquid interface. Specifically, it can be produced by providing an alignment layer directly on the transparent support and then forming an optically anisotropic layer directly on the alignment layer.

[Horizontal alignment agent]
In the present invention, the liquid crystal compound molecule is obtained by containing at least one of the compounds (horizontal alignment agents) represented by the following general formulas (1) to (3) in the optical anisotropic layer forming solution. Can be substantially horizontally oriented. In the present invention, “horizontal alignment” means that in the case of a rod-like liquid crystal, the molecular long axis is parallel to the horizontal plane of the transparent support. In the case of a disc-like liquid crystal, the disc surface of the core of the disc-like liquid crystal compound. And the horizontal plane of the transparent support is parallel, but it is not required to be strictly parallel, and in this specification, an inclination angle with the horizontal plane is less than 10 degrees. To do. The inclination angle is preferably 0 to 5 degrees, more preferably 0 to 3 degrees, further preferably 0 to 2 degrees, and most preferably 0 to 1 degree.
Hereinafter, the following general formulas (1) to (3) will be described in order.

式中、Ｒ¹、Ｒ²及びＲ³は各々独立して、水素原子又は置換基を表し、Ｘ¹、Ｘ²及びＸ³は単結合又は二価の連結基を表す。Ｒ¹〜Ｒ³で各々表される置換基としては、好ましくは置換もしくは無置換の、アルキル基（中でも、無置換のアルキル基又はフッ素置換アルキル基がより好ましい）、アリール基（中でもフッ素置換アルキル基を有するアリール基が好ましい）、置換もしくは無置換のアミノ基、アルコキシ基、アルキルチオ基、ハロゲン原子である。Ｘ¹、Ｘ²及びＸ³で各々表される二価の連結基は、アルキレン基、アルケニレン基、二価の芳香族基、二価のヘテロ環残基、−ＣＯ−、―ＮＲ^a−（Ｒ^aは炭素原子数が１〜５のアルキル基又は水素原子）、−Ｏ−、−Ｓ−、−ＳＯ−、−ＳＯ₂−及びそれらの組み合わせからなる群より選ばれる二価の連結基であることが好ましい。二価の連結基は、アルキレン基、フェニレン基、−ＣＯ−、−ＮＲ^a−、−Ｏ−、−Ｓ−及び−ＳＯ₂−からなる群より選ばれる二価の連結基又は該群より選ばれる基を少なくとも二つ組み合わせた二価の連結基であることがより好ましい。アルキレン基の炭素原子数は、１〜１２であることが好ましい。アルケニレン基の炭素原子数は、２〜１２であることが好ましい。二価の芳香族基の炭素原子数は、６〜１０であることが好ましい。

In the formula, R ¹ , R ² and R ³ each independently represent a hydrogen atom or a substituent, and X ¹ , X ² and X ^{3 each} represent a single bond or a divalent linking group. The substituent represented by each of R ^{1 to} R ³ is preferably a substituted or unsubstituted alkyl group (more preferably an unsubstituted alkyl group or a fluorine-substituted alkyl group), an aryl group (particularly a fluorine-substituted alkyl). An aryl group having a group is preferred), a substituted or unsubstituted amino group, an alkoxy group, an alkylthio group, and a halogen atom. The divalent linking groups represented by X ¹ , X ² and X ³ are each an alkylene group, an alkenylene group, a divalent aromatic group, a divalent heterocyclic residue, —CO—, —NR ^a — ( R ^a is ^a divalent linking group selected from the group consisting of an alkyl group having 1 to 5 carbon atoms or a hydrogen atom), —O—, —S—, —SO—, —SO ₂ — and combinations thereof. Preferably there is. The divalent linking group is selected from the group consisting of an alkylene group, a phenylene group, —CO—, —NR ^a —, —O—, —S—, and —SO ₂ —. It is more preferable that the divalent linking group is a combination of at least two groups. The alkylene group preferably has 1 to 12 carbon atoms. The alkenylene group preferably has 2 to 12 carbon atoms. The number of carbon atoms of the divalent aromatic group is preferably 6-10.

In the formula, R represents a substituent, and m represents an integer of 0 to 5. When m represents an integer greater than or equal to 2, several R may be same or different. Preferred substituents for R are the same as those recited as preferred ranges for the substituents represented by R ¹ , R ² , and R ³ . m preferably represents an integer of 1 to 3, particularly preferably 2 or 3.

In the formula, R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ each independently represent a hydrogen atom or a substituent. The substituents represented by R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ are each preferably a substituent represented by R ¹ , R ² and R ³ in the general formula (I). It is listed as a thing. As the horizontal alignment agent used in the present invention, the compounds described in Japanese Patent Application No. 2005-99248 can be used, and the synthesis method of these compounds is also described in the specification.

  The amount of the compound represented by the general formulas (1) to (3) is preferably 0.01 to 20% by mass, and 0.01 to 10% by mass based on the mass of the liquid crystal compound. Is more preferable, and 0.02 to 1% by mass is particularly preferable. In addition, the compounds represented by the general formulas (1) to (3) may be used alone or in combination of two or more.

  In the present invention, the optically anisotropic layer receives light having a wavelength of λ nm from a direction inclined by + 40 ° with respect to the normal direction of the optical compensation film with an in-plane slow axis as an inclination axis (rotation axis). Retardation value measured and retardation measured by making light of wavelength λ nm incident from a direction inclined −40 ° with respect to the normal direction of the optical compensation film with the in-plane slow axis as the tilt axis (rotation axis) It is preferable to have optical properties that the values are substantially equal. When using a rod-like liquid crystalline compound having a reactive group, in order to develop biaxiality, the cholesteric alignment or the hybrid cholesteric alignment that is twisted while the inclination angle gradually changes in the thickness direction may be distorted by polarized light irradiation. is necessary. As a method of distorting the alignment by irradiation with polarized light, a method using a dichroic liquid crystalline polymerization initiator (WO03 / 054111 A1) or a method using a rod-like liquid crystalline compound having a photoalignable functional group such as a cinnamoyl group in the molecule (Japanese Patent Laid-Open No. 2002-6138). Any of them can be used in the present invention.

  The Re of the optically anisotropic layer is preferably 5 to 250 nm, more preferably 10 to 100 nm, and most preferably 20 to 80 nm. Rth is preferably 30 to 500 nm in total with Rth of the transparent support, more preferably 40 to 400 nm, and most preferably 100 to 350 nm.

  In the case of laminating two or more optically anisotropic layers, the combination of liquid crystalline compounds is not particularly limited, and is a laminate of layers composed of all discotic liquid crystalline compounds, a laminate of layers composed of all rod-like liquid crystalline compounds, It may be a laminate of a layer made of a discotic liquid crystalline compound and a layer made of a rod-like liquid crystalline compound. It is preferable that at least one layer consists of a rod-like liquid crystalline compound. The combination of the alignment states of the layers is not particularly limited, and optically anisotropic layers having the same alignment state may be stacked, or optically anisotropic layers having different alignment states may be stacked. In particular, the optically anisotropic layer preferably exhibits a cholesteric phase before irradiation with polarized ultraviolet rays.

  The optically anisotropic layer is obtained by applying a coating liquid containing a liquid crystalline compound and the following polymerization initiator and other additives on a support (when another layer such as an alignment layer is formed on the support). It is formed by applying and drying on the surface of the layer) by, for example, a continuous conveyance process and curing under predetermined conditions described later. As the solvent used for preparing the coating solution, an organic solvent is preferably used. Examples of organic solvents include amides (eg, N, N-dimethylformamide), sulfoxides (eg, dimethyl sulfoxide), heterocyclic compounds (eg, pyridine), hydrocarbons (eg, benzene, hexane), alkyl halides (eg, , Chloroform, dichloromethane), esters (eg, methyl acetate, butyl acetate), ketones (eg, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone), ethers (eg, tetrahydrofuran, 1,2-dimethoxyethane). Alkyl halides and ketones are preferred. Two or more organic solvents may be used in combination. Application | coating of a coating liquid can be implemented by a well-known method (For example, extrusion coating method, direct gravure coating method, reverse gravure coating method, die coating method), for example using a continuous conveyance process.

[Optical alignment by polarized irradiation]
The optically anisotropic layer can generate in-plane retardation by photo-alignment by polarized light irradiation. In the case where there are a plurality of ultraviolet irradiation processes including polarized light irradiation, it is necessary to first perform polarized light irradiation after applying and drying the liquid crystal compound layer in order to obtain a large in-plane retardation. The polarized light irradiation is preferably performed in an inert gas atmosphere having an oxygen concentration of 0.5% or less. The irradiation energy is preferably ^{20mJ / cm 2 ~10J / cm 2} , further preferably 20~800mJ / cm ^2. The illuminance is preferably 20~1200mW / cm ^2, more preferably 50~1000mW / cm ^2, further preferably 100~800mW / cm ^2. Although there is no restriction | limiting in particular about the kind of liquid crystalline compound hardened | cured by polarized irradiation, The liquid crystalline compound (more preferably rod-shaped liquid crystalline compound) which has an ethylenically unsaturated group as a reactive group is preferable. The irradiation wavelength preferably has a peak at 300 to 450 nm, and more preferably has a peak at 350 to 400 nm.
Note that the optically anisotropic layer exhibiting in-plane retardation generated by photo-alignment due to polarized light irradiation is particularly excellent in optically compensating a VA mode liquid crystal display device.

[Post-curing by UV irradiation after polarized irradiation]
In the present invention, the optically anisotropic layer is further irradiated with polarized or non-polarized ultraviolet light after the first polarized irradiation, thereby increasing the reaction rate of the reactive group (post-curing), improving the adhesion and the like, It is possible to produce at a high conveyance speed. The ultraviolet rays used for post-curing in the present invention may be polarized or non-polarized, but are preferably polarized. Moreover, it is preferable to carry out post-curing twice or more, and polarized light or non-polarized light may be combined with polarized light and non-polarized light. However, when combined, it is preferable to irradiate polarized light before non-polarized light. At the time of ultraviolet irradiation, the inert gas may or may not be replaced, but it is preferably performed in an inert gas atmosphere having an oxygen concentration of 0.5% or less. UV irradiation energy in the post-curing is preferably ^{20mJ / cm 2 ~10J / cm 2} , further preferably 20~300mJ / cm ^2. The illuminance is preferably 20~1200mW / cm ^2, more preferably 50~1000mW / cm ^2, further preferably 100~800mW / cm ^2. In the case of polarized light irradiation, the irradiation wavelength preferably has a peak at 300 to 450 nm, and more preferably 350 to 400 nm. In the case of non-polarized light irradiation, it preferably has a peak at 200 to 450 nm, and more preferably has a peak at 250 to 400 nm.

  Examples of the photopolymerization initiator used in the solution for forming an optically anisotropic layer in the present invention include α-carbonyl compounds (described in the specifications of US Pat. Nos. 2,367,661 and 2,367,670), acyloin ether (US Pat. 2448828 description), α-hydrocarbon substituted aromatic acyloin compounds (described in US Pat. No. 2,722,512), polynuclear quinone compounds (described in US Pat. Nos. 3,046,127 and 2,951,758), triarylimidazole dimers, Combination with p-aminophenyl ketone (described in U.S. Pat. No. 3,549,367), acridine and phenazine compounds (described in JP-A-60-105667, U.S. Pat. No. 4,239,850) and oxadiazole compounds (U.S. Pat. No. 4,212,970) Description).

  The amount of the photopolymerization initiator used is preferably 0.01 to 20% by mass, more preferably 0.5 to 5% by mass, based on the solid content of the coating solution. In order to accelerate the photopolymerization reaction, light irradiation may be performed under heating conditions. In polarized ultraviolet irradiation and / or non-polarized ultraviolet irradiation, the surface temperature of the optically anisotropic layer is preferably kept at 40 ° C. or higher and below the ISO transition temperature of the liquid crystal compound applied in the optically anisotropic layer.

  According to the present invention, by controlling the film surface temperature at the time of ultraviolet irradiation that governs the optically anisotropic layer hardening film of the optical compensation film, the adhesion improvement of the optically anisotropic layer which becomes a problem at the time of rework of the polarizing plate protective film, In addition, an optical compensation film having excellent optical compensation characteristics can be produced.

[Method of curing optically anisotropic layer]
The curing of the optically anisotropic layer will be described in detail.
In the present invention, an optically anisotropic layer is formed by applying and drying a composition for forming an optically anisotropic layer containing a liquid crystalline compound having an isotropic phase transition temperature T ° C. having at least one polymerizable group on a support. Then, the optically anisotropic layer is cured by irradiating the optically anisotropic layer with ultraviolet rays at least once in an atmosphere of 40 ° C. or higher and T ° C. or lower and an oxygen concentration of 10% by volume or lower. .
By curing under such conditions, an optically anisotropic layer having high adhesion and desired optical characteristics can be stably formed.
Furthermore, it is preferable to carry out curing simultaneously or continuously with the laminate in which the optically anisotropic layer is formed on the support in an atmosphere having an oxygen concentration of 10% by volume or less. By carrying out such a conveying step before carrying out the curing, the oxygen concentration inside the surface and inside of the optically anisotropic layer before curing can be effectively reduced, and curing can be promoted.
In addition, the curing reaction initiated by ultraviolet rays is accelerated by heat by heating in an atmosphere with an oxygen concentration of 10% by volume or less simultaneously and / or continuously with curing by ultraviolet irradiation, resulting in excellent physical strength and chemical resistance. A film can be formed.

In the production method of the present invention, the optically anisotropic layer is further cured under any of the following conditions (i) to (iv), or a transporting process under predetermined conditions is performed before and after the curing. preferable.
(I) A curing step of curing by UV irradiation at 40 ° C. or more and T ° C. or less and an oxygen concentration of 10% by volume or less is performed.
(Ii) The curing step is performed continuously to the conveying step of conveying at an oxygen concentration of 3% by volume or less and / or 40 ° C. or more and T ° C. or less.
(Iii) Continuing from the curing step, a conveying step of conveying at an oxygen concentration of 10% or less and / or 40 ° C. or higher and T ° C. or lower is performed.
(Iv) Any two combinations of (i) to (iii) are performed.

  The oxygen concentration during ultraviolet irradiation is preferably 3% by volume or less, and more preferably 1% by volume or less. Further, the oxygen concentration at the time of heating after ultraviolet irradiation and after curing performed as desired is preferably 10% by volume or less, more preferably 5% by volume or less, still more preferably 3% by volume or less, and most preferably 1% by volume. As a means for reducing the oxygen concentration, it is preferable to replace the atmosphere (nitrogen concentration of about 79% by volume, oxygen concentration of about 21% by volume) with another inert gas. Examples of the inert gas include chemically very inert gas (helium, argon, nitrogen), and chlorofluorocarbon, carbon dioxide gas, etc. described in Attached Table 6 of the Regulation for Prevention of Oxygen Deficiency. Nitrogen is particularly inexpensive and can be suitably used because it is chemically stable and inexpensive.

  Further, in order to maintain the oxygen concentration within the above range and to achieve a predetermined temperature, an oxygen shielding gas having a predetermined temperature (preferably 40 ° C. or higher) is injected into the zone in the curing step and / or the conveying step. Is preferred. The inert gas used to lower the oxygen concentration in the zone in which the curing step and / or the conveyance step are performed may be exhausted to the previous low oxygen concentration zone and / or the subsequent conveyance zone. Such a configuration is preferable from the viewpoint of reducing the manufacturing cost by effectively using an inert gas.

The heating in the ultraviolet irradiation may be performed from the time of the ultraviolet irradiation, the film surface is 40 ° C. or higher, and the isotropic phase (ISO) transition temperature T ° C. or lower of the liquid crystal compound contained in the optically anisotropic layer. It is preferable to be heated at. If it is less than 40 ° C., the effect of heating cannot be obtained, and if it exceeds T ° C., desired optical characteristics cannot be obtained.
Furthermore, this preferable temperature is 50 degreeC-(T-10) degreeC. The film surface refers to the film surface temperature of the layer to be cured, that is, the optically anisotropic layer.
The time for the film surface to reach the temperature is preferably from 10 seconds before the start of UV irradiation to 300 seconds or less after the start of UV irradiation, and more preferably from 10 seconds before the start of UV irradiation to 10 seconds or less after the start of UV irradiation. If the time for maintaining the temperature of the film surface in the above temperature range is too short, the reaction of the curable composition for forming a film cannot be promoted, and production problems such as an increase in equipment arise.

The heating method is not particularly limited, but it is preferable that an oxygen shielding gas of 40 ° C. or higher and T ° C. or lower is injected into the zone in the ultraviolet irradiation step, and in the conveying step and the post-heating step that are implemented as desired. In addition to or instead of spraying, a method of heating a roll to contact the film, a method of spraying heated nitrogen, irradiation of far infrared rays or infrared rays may be applied. A method of heating a rotating metal roll described in Japanese Patent No. 2523574 by flowing warm water or steam can also be used.
When the liquid crystal compound is included in the optically anisotropic layer as in the present invention, and the distribution of the liquid crystal in the film or the disturbance of the director directly affects the optical characteristics, the film of the entire film including the support It is necessary to keep the temperature distribution in the thickness direction constant. A method of spraying heated nitrogen, irradiation of far infrared rays or infrared rays can be preferably used. When the temperature of the film is controlled by bringing it into contact with the heated roll, it is necessary to keep the temperature distribution in the film thickness direction uniform, but in that case, it may be carried out in combination with a method of blowing heated nitrogen. It is valid.

[Alignment layer]
The optical compensation film or transfer material of the present invention may have an alignment layer between the support and the optically anisotropic layer. The alignment layer can be formed by applying and drying an alignment layer forming solution on a transparent support or an undercoat layer coated on the transparent support. The alignment layer is used for defining the alignment direction of the liquid crystal compound contained in the optically anisotropic layer provided thereon. The orientation layer may be any layer as long as it can impart orientation to the optically anisotropic layer. Preferable examples of the alignment layer include a layer subjected to a rubbing treatment of an organic compound (preferably a polymer), an oblique deposition layer of an inorganic compound, and a layer having a microgroove, ω-tricosanoic acid, dioctadecylmethylammonium chloride and stearyl. Examples thereof include a cumulative film formed by Langmuir-Blodgett method (LB film) such as methyl acid, or a layer in which a dielectric is oriented by applying an electric field or a magnetic field.

  Examples of organic compounds for the alignment layer include polymethyl methacrylate, acrylic acid / methacrylic acid copolymer, styrene / maleimide copolymer, polyvinyl alcohol, poly (N-methylolacrylamide), styrene / vinyltoluene copolymer. , Polymers such as chlorosulfonated polyethylene, nitrocellulose, polyvinyl chloride, chlorinated polyolefin, polyester, polyimide, vinyl acetate / vinyl chloride copolymer, ethylene / vinyl acetate copolymer, carboxymethyl cellulose, polyethylene, polypropylene and polycarbonate, and Examples of the compound include a silane coupling agent. Examples of preferred polymers include polyimide, polystyrene, polymers of styrene derivatives, gelatin, polyvinyl alcohol, and alkyl-modified polyvinyl alcohol having an alkyl group (preferably having 6 or more carbon atoms).

  For forming the alignment layer, it is preferable to use a polymer. The type of polymer that can be used can be determined according to the orientation (particularly the average tilt angle) of the liquid crystal compound. For example, in order to align the liquid crystalline compound horizontally, a polymer that does not decrease the surface energy of the alignment film (ordinary alignment polymer) can be used. Specific types of polymers are described in various documents about liquid crystal cells or optical compensation films. For example, polyvinyl alcohol or modified polyvinyl alcohol, a copolymer with polyacrylic acid or polyacrylate, polyvinyl pyrrolidone, cellulose, or modified cellulose are preferably used. Any of the alignment films preferably has a polymerizable group for the purpose of improving the adhesion between the liquid crystal compound and the transparent support. The polymerizable group can be introduced by introducing a repeating unit having a polymerizable group in the side chain or as a substituent of a cyclic group. It is more preferable to use an alignment film that forms a chemical bond with a liquid crystal compound at the interface. Such an alignment film is described in JP-A-9-152509, and acid chloride or Karenz MOI (manufactured by Showa Denko KK). The modified polyvinyl alcohol in which an acrylic group is introduced into the side chain by using The thickness of the alignment film is preferably 0.01 to 5 μm, and more preferably 0.05 to 2 μm.

  A polyimide film (preferably fluorine atom-containing polyimide) widely used as an alignment layer for LCD is also preferable as the organic alignment layer. For this, polyamic acid (for example, LQ / LX series manufactured by Hitachi Chemical Co., Ltd., SE series manufactured by Nissan Chemical Co., Ltd., etc.) was applied to the support surface and baked at 100 to 300 ° C. for 0.5 to 1 hour. Thereafter, it is obtained by rubbing. Furthermore, the alignment layer used in the present invention can be obtained by introducing a reactive group into the polymer or by using the polymer together with a crosslinking agent such as an isocyanate compound and an epoxy compound to cure these polymers. It is preferable that it is a cured film obtained.

  Moreover, the rubbing process can utilize a processing method widely adopted as a liquid crystal alignment process of LCD. That is, a method of obtaining the orientation by rubbing the surface of the orientation layer in a certain direction using paper, gauze, felt, rubber, nylon, polyester fiber or the like can be used. In general, it is carried out by rubbing several times using a cloth in which fibers having a uniform length and thickness are flocked on average. In this invention, after apply | coating and drying the solution for alignment layer formation, it is preferable to carry out the rubbing process of the alignment layer, conveying the transparent support body which provided the alignment layer, for example using a continuous conveyance process.

Moreover, as a vapor deposition material for the inorganic oblique vapor deposition film, SiO ₂ is representative, and metal oxides such as TiO ₂ and ZnO ₂ , fluorides such as MgF ₂ , and metals such as Au and Al are also exemplified. . The metal oxide can be used as an oblique deposition material as long as it has a high dielectric constant, and is not limited to the above. The inorganic oblique deposition film can be formed using a deposition apparatus. An inorganic oblique vapor deposition film can be formed by fixing the film (support) and performing vapor deposition, or moving the long film and performing continuous vapor deposition.

  The alignment layer forming solution preferably contains a polymer having a reactive group in the side chain, or a monomer or oligomer having a reactive group, specifically, a modified polyvinyl alcohol having a reactive group in the side chain. Examples of the reactive group include the reactive groups described above. Moreover, it is preferable that a reactive group can react directly with the reactive group which the liquid crystalline compound used for an optically anisotropic layer has. When the compound of the alignment layer and the optically anisotropic layer undergoes a direct crosslinking reaction, the adhesion of the completed film can be imparted.

  The optically anisotropic layer of the optical compensation film of the present invention may be transferred by, for example, using a pressure-sensitive adhesive on the transparent support after aligning the liquid crystalline compound on the temporary alignment layer and fixing the alignment. However, it is preferable to form the optical compensation film directly without transfer from the viewpoint of productivity.

  Each of the optically anisotropic layer and the alignment layer is formed by a dip coating method, an air knife coating method, a curtain coating method, a roller coating method, a wire bar coating method, a gravure coating method, or an extrusion coating method (US Pat. No. 2,681,294). Can be applied. Two or more layers may be applied simultaneously. The method of simultaneous application is described in US Pat. Nos. 2,761,791, 2,941,898, 3,508,947, and 3,526,528 and Yuji Harasaki, Coating Engineering, page 253, Asakura Shoten (1973).

[Support]
The optical compensation film and the transfer material of the present invention have a support. In the optical compensation film, the support is preferably transparent so that the support does not block light, and in the transfer material, the support is preferably transparent so that the exposure to the photosensitive resin layer is not hindered. It is preferable to use a polymer film that is 80% or more. The thickness of the support is preferably 10 to 500 μm, more preferably 20 to 200 μm, and most preferably 35 to 110 μm.

  The glass transition temperature (Tg) of the support is appropriately determined according to the purpose of use. The glass transition temperature of the resin is preferably 70 ° C. or higher, more preferably 75 ° C. to 200 ° C., and particularly preferably 80 ° C. to 180 ° C. When a resin having a glass transition temperature in this range is employed, heat resistance and molding processability are highly balanced, which is preferable.

  The Re of the support is preferably adjusted to a range of −200 to 100 nm, and Rth is preferably adjusted to a range of −100 to 100 nm. Re is more preferably −50 to 30 nm, and most preferably −30 to 20 nm. In the present specification, negative Re means that the in-plane slow axis of the support is in a direction (TD direction) perpendicular to the film transport direction, and negative Rth means that the refractive index in the thickness direction is the in-plane average refractive index. It means bigger than. In order to improve the color, it is preferable that the in-plane slow axis of the support is in the TD direction.

  As the polymer constituting the support, for example, cellulose-based polymers and cycloolefin-based polymers can be used. Specifically, cellulose esters (eg, cellulose acetate, cellulose propionate, cellulose butyrate), polyolefins (Eg, norbornene polymers), poly (meth) acrylic acid esters (eg, polymethyl methacrylate), polycarbonates, polyesters and polysulfones, and norbornene polymers can be used. From the viewpoint of low birefringence, cellulose esters and norbornene-based polymers are preferable, and as commercially available norbornene-based polymers, Arton (manufactured by JSR Corporation), Zeonex, Zeonore (above, Nippon Zeon Corporation) and the like are used. Can do.

  In particular, when used as a protective film for a polarizing plate, a cellulose ester is preferable, and a lower fatty acid ester of cellulose is more preferable. Lower fatty acid means a fatty acid having 6 or less carbon atoms. The number of carbon atoms is preferably 2 (cellulose acetate), 3 (cellulose propionate) or 4 (cellulose butyrate). Mixed fatty acid esters such as cellulose acetate propionate and cellulose acetate butyrate may be used. Of the lower fatty acid esters of cellulose, cellulose acetate is most preferred. The acyl group substitution degree of the cellulose ester is preferably 2.50 to 3.00, more preferably 2.75 to 2.95, and most preferably 2.80 to 2.90.

  The viscosity average polymerization degree (DP) of the cellulose ester is preferably 250 or more, and more preferably 290 or more. In addition, the cellulose ester preferably has a narrow molecular weight distribution of Mm / Mn (Mm is a mass average molecular weight, Mn is a number average molecular weight) by gel permeation chromatography. The value of Mm / Mn is preferably 1.0 to 5.0, more preferably 1.3 to 3.0, and most preferably 1.4 to 2.0.

  In the cellulose ester, the hydroxyl groups at the 2-position, 3-position and 6-position of cellulose are not evenly substituted but the degree of substitution at the 6-position tends to be small. In the present invention, the 6-position substitution degree of the cellulose ester is preferably about the same as or higher than the 2-position and 3-position. The ratio of the 6-position substitution degree to the total of the 2-position, 3-position and 6-position substitution degrees is preferably 30 to 40%. The ratio of the 6-position substitution degree is preferably 31% or more, particularly preferably 32% or more. The substitution degree at the 6-position is preferably 0.88 or more. The 6-position of cellulose may be substituted with an acyl group having 3 or more carbon atoms (eg, propionyl, butyryl, valeroyl, benzoyl, acryloyl) in addition to acetyl. The degree of substitution at each position can be measured by NMR. Cellulose esters having a high degree of substitution at the 6-position are described in Synthesis Example 1 described in Paragraph Nos. 0043 to 0044, Synthesis Example 2 described in Paragraph Nos. 0048 to 0049, and Paragraph Nos. 0051 to 0052. It can synthesize | combine with reference to the synthesis example 3 of.

  A plasticizer can be added to the cellulose ester film in order to improve mechanical properties or increase the drying speed. As the plasticizer, phosphoric acid ester or carboxylic acid ester is used. Examples of phosphate esters include triphenyl phosphate (TPP), biphenyl diphenyl phosphate and tricresyl phosphate (TCP). Representative examples of the carboxylic acid ester include phthalic acid esters and citric acid esters. Examples of phthalic acid esters include dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), dioctyl phthalate (DOP), diphenyl phthalate (DPP) and diethyl hexyl phthalate (DEHP). Examples of citrate esters include triethyl O-acetylcitrate (OACTE) and tributyl O-acetylcitrate (OACTB). Examples of other carboxylic acid esters include butyl oleate, methylacetyl ricinoleate, dibutyl sebacate, and various trimellitic acid esters. Phthalate plasticizers (DMP, DEP, DBP, DOP, DPP, DEHP) are preferably used. DEP and DPP are particularly preferred. The addition amount of the plasticizer is preferably 0.1 to 25% by mass of the amount of cellulose ester, more preferably 1 to 20% by mass, and most preferably 3 to 15% by mass.

  A degradation inhibitor (eg, antioxidant, peroxide decomposer, radical inhibitor, metal deactivator, acid scavenger, amine) may be added to the cellulose ester film. The deterioration preventing agents are described in JP-A-3-199201, JP-A-51907073, JP-A-5-194789, JP-A-5-271471, and JP-A-6-107854. The addition amount of the deterioration preventing agent is preferably 0.01 to 1% by mass of the solution (dope) to be prepared, and more preferably 0.01 to 0.2% by mass. When the addition amount is less than 0.01% by mass, the effect of the deterioration preventing agent is hardly recognized. When the addition amount exceeds 1% by mass, bleed-out (bleeding) of the deterioration preventing agent to the film surface may be observed. Examples of particularly preferred deterioration inhibitors include butylated hydroxytoluene (BHT) and tribenzylamine (TBA). Furthermore, a very small amount of dye may be added to prevent light piping. From the viewpoint of transmittance, it is preferable to adjust the type and amount so that the transmittance of light having a wavelength of 420 nm is 50% or more. The added amount of the dye is preferably 0.01 ppm to 1 ppm.

  A retardation control agent can be added to the cellulose ester film in order to control Re and Rth. The retardation control agent is preferably used in the range of 0.01 to 20 parts by mass, more preferably 0.05 to 15 parts by mass, with respect to 100 parts by mass of the cellulose ester. Most preferably, it is used in the range of 1 to 10 parts by mass. Two or more retardation control agents may be used in combination. The retardation control agent is described in pamphlets of WO01 / 88574 and WO00 / 2619, and JP-A 2000-1111914 and 2000-275434.

  The cellulose ester film can be produced by a solvent cast method using a solution containing cellulose ester and other components as a dope. The dope can be cast on a drum or band and the solvent evaporated to form a film. It is preferable to adjust the concentration of the dope before casting so that the solid content is 10 to 40% by mass. The solid content is more preferably 18 to 35% by mass. Two or more dopes can be cast. The surface of the drum or band is preferably finished in a mirror state. For casting and drying methods in the solvent casting method, U.S. Pat. No. 736892, JP-B Nos. 45-4554, 49-5614, JP-A-60-176834, No. 60-203430, and No. 62-1115035.

  The dope is preferably cast on a drum or band having a surface temperature of 10 ° C. or less. After casting, it is preferable to dry it by applying air for 2 seconds or more. Then, the method can be employed in which the obtained film is peeled off from the drum or the band and further dried with high-temperature air at different temperatures of 100 to 160 ° C. to evaporate the residual solvent (described in Japanese Patent Publication No. 5-17844). . According to this method, it is possible to shorten the time from casting to stripping. In order to carry out this method, it is necessary for the dope to gel at the surface temperature of the drum or band during casting. When casting a plurality of cellulose ester solutions, a solution is prepared by casting a solution containing cellulose ester from a plurality of casting openings provided at intervals in the traveling direction of the support, and laminating them. (Japanese Unexamined Patent Publication Nos. 61-158414, 1-122419, and 11-198285). A film can also be produced by casting a cellulose ester solution from two casting ports (Japanese Patent Publication Nos. 60-27562, 61-94724, 61-947245, 61-104413, 61-158413 and JP-A-6-134933). Employs a method of casting a cellulose ester film (described in JP-A-56-162617) by wrapping a flow of a high-viscosity cellulose ester solution with a low-viscosity cellulose ester solution and extruding a high-viscosity and low-viscosity cellulose ester solution simultaneously. May be.

  The retardation of the cellulose ester film can be further adjusted by a stretching treatment. The draw ratio is preferably in the range of 3 to 100%. Tenter stretching is preferred. In order to control the slow axis with high accuracy, it is preferable to make the difference between the left and right tenter clip speeds and the separation timing as small as possible. The stretching process is described on page 37, line 8 to page 38, line 8 of the pamphlet of WO 01/88574.

  The cellulose ester film can be subjected to a surface treatment. Examples of the surface treatment include corona discharge treatment, glow discharge treatment, flame treatment, acid treatment, alkali treatment, and ultraviolet irradiation treatment. From the viewpoint of maintaining the flatness of the film, the temperature of the cellulose ester film in the surface treatment is preferably Tg (glass transition temperature) or lower, specifically 150 ° C. or lower.

  The thickness of the cellulose ester film can be adjusted by lip flow rate and line speed, or stretching or compression when it is produced by film formation. Since the moisture permeability varies depending on the main material to be used, it is possible to obtain a preferable moisture permeability range as a protective film for the polarizing plate by adjusting the thickness. Moreover, the free volume of the said cellulose-ester film can be adjusted with drying temperature and time, when producing by film forming. Also in this case, since the moisture permeability varies depending on the main material used, it is possible to make the moisture permeability range preferable as a protective film by adjusting the free volume. The hydrophilicity / hydrophobicity of the cellulose ester film can be adjusted by an additive. Moisture permeability is increased by adding a hydrophilic additive in the free volume, and conversely, moisture permeability can be lowered by adding a hydrophobic additive. Thus, by adjusting the moisture permeability of the cellulose ester film by various methods, the range of moisture permeability that is preferable as a protective film of the polarizing plate can be obtained, and the support of the optically anisotropic layer is protected for the polarizing plate. A polarizing plate that can also serve as a film and has optical compensation ability can be manufactured at low cost with high productivity.

The transfer material of the present invention has a photosensitive resin layer on the optically anisotropic layer.
[Photosensitive resin layer]
The photosensitive resin layer used for the transfer material of the present invention is made of a photosensitive resin composition. The photosensitive resin layer is preferably formed from a resin composition containing at least (1) an alkali-soluble resin, (2) a monomer or an oligomer, and (3) a photopolymerization initiator or a photopolymerization initiator system. . In addition, in the embodiment in which the optically anisotropic layer is formed simultaneously with the color filter on the substrate, (4) it is preferably formed from a colored resin composition containing a colorant such as a dye or pigment.
Hereinafter, the components (1) to (4) will be described.

(1) Alkali-soluble resin The alkali-soluble resin (hereinafter sometimes simply referred to as “binder”) is preferably a polymer having a polar group such as a carboxylic acid group or a carboxylic acid group in the side chain. Examples thereof include JP-A-59-44615, JP-B-54-34327, JP-B-58-12577, JP-B-54-25957, JP-A-59-53836, and JP-A-57-36. A methacrylic acid copolymer, an acrylic acid copolymer, an itaconic acid copolymer, a crotonic acid copolymer, a maleic acid copolymer, a partially esterified maleic acid copolymer as described in JP-A-59-71048 Etc. Moreover, the cellulose derivative which has a carboxylic acid group in a side chain can also be mentioned, In addition to this, what added the cyclic acid anhydride to the polymer which has a hydroxyl group can also be used preferably. Further, as particularly preferred examples, copolymers of benzyl (meth) acrylate and (meth) acrylic acid described in US Pat. No. 4,139,391, benzyl (meth) acrylate, (meth) acrylic acid and other monomers And a multi-component copolymer. The binder polymer having these polar groups may be used alone or in the form of a composition used in combination with a normal film-forming polymer, and the content relative to the total solid content of the colored resin composition 20-50 mass% is common, and 25-45 mass% is preferable.

(2) Monomer or oligomer The radical polymerizable monomer or oligomer used in the photosensitive resin layer is a monomer or oligomer that has two or more ethylenically unsaturated double bonds and undergoes addition polymerization by light irradiation. It is preferable. Examples of such monomers and oligomers include compounds having at least one addition-polymerizable ethylenically unsaturated group in the molecule and having a boiling point of 100 ° C. or higher at normal pressure. Examples include monofunctional acrylates and monofunctional methacrylates such as polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate and phenoxyethyl (meth) acrylate; polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) ) Acrylate, trimethylolethane triacrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane diacrylate, neopentyl glycol di (meth) acrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, di Pentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, hexane All di (meth) acrylate, trimethylolpropane tri (acryloyloxypropyl) ether, tri (acryloyloxyethyl) isocyanurate, tri (acryloyloxyethyl) cyanurate, glycerin tri (meth) acrylate; multifunctional such as trimethylolpropane and glycerin Polyfunctional acrylates and polyfunctional methacrylates such as those obtained by adding ethylene oxide or propylene oxide to alcohol and then (meth) acrylated can be mentioned.

Further, urethane acrylates described in JP-B-48-41708, JP-B-50-6034 and JP-A-51-37193; JP-A-48-64183, JP-B-49-43191 And polyester acrylates described in Japanese Patent Publication No. 52-30490; polyfunctional acrylates and methacrylates such as epoxy acrylates which are reaction products of epoxy resin and (meth) acrylic acid.
Among these, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and dipentaerythritol penta (meth) acrylate are preferable.
In addition, “polymerizable compound B” described in JP-A-11-133600 can also be mentioned as a preferable example.
These monomers or oligomers may be used alone or in admixture of two or more. The content of the colored resin composition with respect to the total solid content is generally 5 to 50% by mass, and 10 to 40% by mass. Is preferred.

  Examples of the cationic polymerizable monomer or oligomer used in the photosensitive resin layer include cyclic ethers, cyclic formals, acetals, vinyl alkyl ethers, compounds containing thiirane groups, bisphenol type epoxy resins, novolac type epoxy resins, and alicyclic epoxies. Mention may be made of epoxy compounds such as resins, epoxidized unsaturated fatty acids and epoxidized polybutadiene. Examples of such monomers or oligomers include compounds described in Hiroaki Kakiuchi's “New Epoxy Resin” Shoshodo (published in 1985), “Epoxy Resin” edited by Kuniyuki Hashimoto, Nikkan Kogyo Shimbun (1969), etc. Other trifunctional glycidyl ethers (trimethylolethane triglycidyl ether, trimethylolpropane triglycidyl ether, glycerol triglycidyl ether, triglycidyl trishydroxyethyl isocyanurate, etc.), tetra- or higher functional glycidyl ethers (sorbitol tetraglycidyl ether, Pentaerythritol tetraglycyl ether, polyglycidyl ether of cresol novolac resin, polyglycidyl ether of phenol novolac resin, etc.) trifunctional or higher cycloaliphatic epoxy (Epolide GT-) 01, Epolide GT-401, EHPE (manufactured by Daicel Chemical Industries, Ltd.), phenol novolac resin polycyclohexyl epoxy methyl ether, etc., trifunctional or more oxetanes (OX-SQ, PNOX-1009 (above, Tojo) Synthetic Co., Ltd.) and the like.

(3) Photopolymerization initiator or photopolymerization initiator system As the photopolymerization initiator or photopolymerization initiator system used in the photosensitive resin layer, a vicinal poly disclosed in US Pat. No. 2,367,660 is used. Ketaldonyl compounds, acyloin ether compounds described in US Pat. No. 2,448,828, aromatic acyloin compounds substituted with α-hydrocarbons described in US Pat. No. 2,722,512, US Pat. No. 3,046,127 And a polynuclear quinone compound described in U.S. Pat. No. 2,951,758, a combination of a triarylimidazole dimer described in US Pat. No. 3,549,367 and a p-aminoketone, and a benzoic compound described in JP-B-51-48516 Thiazole compounds and trihalomethyl-s-triazine compounds, US Pat. No. 4,239,850 The listed trihalomethyl - triazine compound include a trihalomethyl oxadiazole compounds described in U.S. Pat. No. 4,212,976. In particular, trihalomethyl-s-triazine, trihalomethyloxadiazole, and triarylimidazole dimer are preferable.
In addition, “polymerization initiator C” described in JP-A-11-133600 can also be mentioned as a preferable example. The content of the photopolymerization initiator or photopolymerization initiator system with respect to the total solid content of the photosensitive resin composition is generally 0.5 to 20% by mass, and preferably 1 to 15% by mass.

  Examples of the cationic polymerization initiator used in the present invention include aryldiazonium salts of Lewis acids such as etrafluoroborate and hexafluorophosphenol, double salts such as diaryliodonium salts and triarylsulfonium luster, benzylsilyl ether, and o-nitrobenzylsilyl. A mixed system of a silanol-generating silane compound such as ether or triphenyl (t-butyl) peroxysilane and an aluminum complex such as tris (ethylacetoacetate) aluminum can be used. The content of the cationic polymerization initiator based on the total solid content of the photosensitive resin composition is generally 0.5 to 20% by mass, and preferably 1 to 15% by mass.

(4) Colorant Known colorants (dyes and pigments) can be added to the colored resin composition. In the case of using a pigment among the known colorants, it is desirable that the pigment is uniformly dispersed in the colored resin composition. Therefore, the particle diameter is preferably 0.1 μm or less, particularly preferably 0.08 μm or less. .
Examples of the known dye or pigment include pigments described in paragraph No. [0033] of JP-A No. 2004-302015 and column 14 of US Pat. No. 6,790,568.

  As the colorant in the present invention, among the above-mentioned colorants, (i) R (red) colored resin composition is C.I. I. Pigment Red 254 is C.I. in (ii) G (green) colored resin composition. I. Pigment Green 36 is C.I. in (iii) B (blue) colored resin composition. I. Pigment Blue 15: 6 is a preferable example. Further, pigments may be used in combination.

  In the present invention, pigment combinations that are preferably used in combination are C.I. I. In pigment red 254, C.I. I. Pigment red 177, C.I. I. Pigment red 224, C.I. I. Pigment yellow 139 or C.I. I. A combination with Pigment Violet 23; I. In Pigment Green 36, C.I. I. Pigment yellow 150, C.I. I. Pigment yellow 139, C.I. I. Pigment yellow 185, C.I. I. Pigment yellow 138 or C.I. I. A combination with CI Pigment Yellow 180, and C.I. I. In Pigment Blue 15: 6, C.I. I. Pigment violet 23 or C.I. I. A combination with Pigment Blue 60 is mentioned.

  C. in the pigment when used together in this way. I. Pigment red 254, C.I. I. Pigment green 36, C.I. I. The content of Pigment Blue 15: 6 is C.I. I. The pigment red 254 is preferably 80% by mass or more, particularly preferably 90% by mass or more. C. I. The pigment green 36 is preferably 50% by mass or more, particularly preferably 60% by mass or more. C. I. Pigment Blue 15: 6 is preferably 80% by mass or more, and particularly preferably 90% by mass or more.

  The pigment is desirably used as a dispersion. This dispersion can be prepared by adding and dispersing a composition obtained by previously mixing the pigment and the pigment dispersant in an organic solvent (or vehicle) described later. The vehicle refers to a portion of a medium in which the pigment is dispersed when the paint is in a liquid state, and is a liquid portion that binds to the pigment and hardens the coating film (binder), and a component that dissolves and dilutes the portion. (Organic solvent). The disperser used for dispersing the pigment is not particularly limited. For example, the kneader described in Kazuzo Asakura, “Encyclopedia of Pigments”, first edition, Asakura Shoten, 2000, 438, Known dispersing machines such as a roll mill, an atrider, a super mill, a dissolver, a homomixer, and a sand mill can be used. Further, fine grinding may be performed using frictional force by mechanical grinding described in Item 310 of the document.

  The colorant (pigment) used in the present invention preferably has a number average particle diameter of 0.001 to 0.1 μm, more preferably 0.01 to 0.08 μm. When the number average particle diameter of the pigment is less than 0.001 μm, the particle surface energy is increased and the particles are easily aggregated, so that it is difficult to disperse the pigment and it is difficult to keep the dispersion state stable. On the other hand, if the number average particle diameter of the pigment exceeds 0.1 μm, the polarization is canceled by the pigment, and the contrast is lowered. The “particle diameter” as used herein refers to the diameter when the electron micrograph image of the particle is a circle of the same area, and the “number average particle diameter” is the above-mentioned particle diameter for a number of particles, The average value of 100 is said.

  The contrast of the colored pixels can be improved by reducing the particle size of the dispersed pigment. Reduction of the particle size can be achieved by adjusting the dispersion time of the pigment dispersion. For dispersion, the known disperser described above can be used. The dispersion time is preferably 10 to 30 hours, more preferably 18 to 30 hours, and most preferably 24 to 30 hours. When the dispersion time is less than 10 hours, the pigment particle size is large, the polarization due to the pigment is canceled, and the contrast may be lowered. On the other hand, if it exceeds 30 hours, the viscosity of the dispersion liquid increases and application may be difficult. Further, in order to make the difference in contrast between two or more colored pixels within 600, the pigment particle diameter is adjusted to obtain a desired contrast.

  The contrast of each colored pixel of the color filter formed from the photosensitive resin layer is preferably 2000 or more, more preferably 2800 or more, still more preferably 3000 or more, and most preferably 3400 or more. When the contrast of each colored pixel constituting the color filter is 2000 or less, when an image of a liquid crystal display device having the color pixel is observed, an overall whitish impression is obtained, which is not preferable. Further, the difference in contrast between the colored pixels is preferably within 600, more preferably within 410, still more preferably within 350, and most preferably within 200. It is preferable that the contrast difference between the colored pixels is within 600 because the amount of light leakage from each colored pixel portion during black display is not significantly different, and the color balance of black display is good.

  In the present specification, “contrast of colored pixels” means a contrast that is individually evaluated for each color of R, G, and B constituting the color filter. The contrast measurement method is as follows. In the state where the polarizing plates are overlapped on both sides of the object to be measured and the polarizing directions of the polarizing plates are parallel to each other, the backlight Y is applied from the side of one polarizing plate, and the luminance Y1 of the light passing through the other polarizing plate is obtained. taking measurement. Next, in a state where the polarizing plates are orthogonal to each other, a backlight is applied from the side of one polarizing plate, and the luminance Y2 of the light passing through the other polarizing plate is measured. The contrast is calculated by Y1 / Y2 using the obtained measurement value. Note that the polarizing plate used for contrast measurement is the same as the polarizing plate used for the liquid crystal display device using the color filter.

  In the color filter formed of the photosensitive resin layer of the present invention, an appropriate surfactant is contained in the colored resin composition from the viewpoint of effectively preventing display unevenness (color unevenness due to film thickness variation). It is preferable to make it. The surfactant can be used as long as it is mixed with the photosensitive resin composition of the present invention. Preferred surfactants used in the present invention include JP2003-337424A [0090] to [0091], JP2003-177522A [0092] to [0093], and JP2003-177523A [0094]. ] To [0095], JP 2003-177521 A [0096] to [0097], JP 2003-177519 A [0098] to [0099], JP 2003-177520 A [0100] to [0101]. [0102] to [0103] of JP-A-11-133600 and surfactants disclosed as inventions of JP-A-6-16684 are preferred. In order to obtain a higher effect, a fluorosurfactant and / or a silicon surfactant (a fluorosurfactant or a silicon surfactant, a surfactant containing both a fluorine atom and a silicon atom) ) Or two or more types are preferable, and a fluorine-based surfactant is most preferable. When using a fluorosurfactant, the number of fluorine atoms in the fluorine-containing substituent in the surfactant molecule is preferably 1 to 38, more preferably 5 to 25, and most preferably 7 to 20. If the number of fluorine atoms is too large, it is not preferable in that the solubility in an ordinary solvent not containing fluorine is lowered. When the number of fluorine atoms is too small, it is not preferable in that the effect of improving unevenness cannot be obtained.

  As a particularly preferred surfactant, a monomer represented by the following general formula (a) and general formula (b) is included, and the mass ratio of the general formula (a) / general formula (b) is 20/80 to 60 / The thing containing 40 copolymers is mentioned.

In the formula, R ¹ , R ² and R ³ each independently represent a hydrogen atom or a methyl group, and R ⁴ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. n represents an integer of 1 to 18, and m represents an integer of 2 to 14. p and q represent integers of 0 to 18, but are not included when both p and q are simultaneously 0.

A particularly preferred surfactant represented by the general formula (a) is referred to as a monomer (a), and a monomer represented by the general formula (b) is referred to as a monomer (b). C _m F _{2m + 1} shown in the general formula (a) may be linear or branched. m shows the integer of 2-14, Preferably it is an integer of 4-12. The content of C _m F _{2m + 1} is preferably 20 to 70% by mass, particularly preferably 40 to 60% by mass, based on the monomer (a). R ₁ represents a hydrogen atom or a methyl group. Moreover, n shows 1-18, and 2-10 are preferable especially. R ₂ and R ₃ shown in the general formula (b) each independently represent a hydrogen atom or a methyl group, and R ₄ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. p and q each represents an integer of 0 to 18, but neither p nor q contains 0. p and q are preferably 2 to 8.

  Moreover, as a particularly preferable monomer (a) contained in one molecule of the surfactant, those having the same structure or those having different structures within the above defined range may be used. The same applies to the monomer (b).

  The weight average molecular weight Mw of the particularly preferable surfactant is preferably 1000 to 40000, and more preferably 5000 to 20000. The surfactant for use in the present invention contains the monomers represented by the general formula (a) and the general formula (b), and the mass ratio of the general formula (a) / the general formula (b) is 20/80 to 60/40. It is characterized by containing the copolymer of these. Particularly preferred 100 parts by weight of the surfactant is preferably such that the monomer (a) is 20 to 60 parts by weight, the monomer (b) is 80 to 40 parts by weight, and other optional monomers are the remaining parts by weight. It is preferable that the monomer (a) is 25 to 60 parts by mass, the monomer (b) is 60 to 40 parts by mass, and the other optional monomers are the remaining parts by mass.

  Examples of the copolymerizable monomer other than the monomers (a) and (b) include styrene, vinyl toluene, α-methyl styrene, 2-methyl styrene, chlorostyrene, vinyl benzoic acid, sodium vinylbenzene sulfonate, and aminostyrene. Styrene and its derivatives, substituted products, dienes such as butadiene and isoprene, acrylonitrile, vinyl ethers, methacrylic acid, acrylic acid, itaconic acid, crotonic acid, maleic acid, partially esterified maleic acid, styrene sulfonic acid maleic anhydride, silica And vinyl monomers such as cinnamate, vinyl chloride and vinyl acetate.

  Particularly preferred surfactants are copolymers such as monomer (a) and monomer (b), but the monomer sequence is not particularly limited and may be random or regular, for example, block or graft. Further, particularly preferable surfactants can be used by mixing two or more of those having different molecular structures and / or monomer compositions.

  As content of the said surfactant, 0.01-10 mass% is preferable with respect to the layer total solid of a photosensitive resin layer, and 0.1-7 mass% is especially preferable. The surfactant of the present invention contains a predetermined amount of a surfactant having a specific structure, an ethylene oxide group, and a polypropylene oxide group, and the photosensitive resin layer is contained in a specific range by containing it in a specific range. Display unevenness of the liquid crystal display device provided is improved. If it is less than 0.01% by mass relative to the total solid content, the display unevenness is not improved, and if it exceeds 10% by mass, the effect of improving the display unevenness does not appear much. When the above-mentioned particularly preferable surfactant is contained in the photosensitive resin layer to produce a color filter, it is preferable in that display unevenness is improved.

  Moreover, the following commercially available surfactant can also be used as it is. Examples of commercially available surfactants that can be used include F-top EF301 and EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430 and 431 (manufactured by Sumitomo 3M Ltd.), MegaFuck F171, F173, F176, F189, and R08. (Dainippon Ink Co., Ltd.), Surflon S-382, SC101, 102, 103, 104, 105, 106 (Asahi Glass Co., Ltd.) and other fluorine-based surfactants, or silicon-based surfactants. be able to. Polysiloxane polymers KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) and Troisol S-366 (manufactured by Troy Chemical Co., Ltd.) can also be used as the silicon surfactant.

The optical compensation film of the present invention may be incorporated in a liquid crystal display device as a polarizing plate integrated with a polarizing film. Furthermore, when the optical compensation film of the present invention functions as a protective film for a polarizing film, the liquid crystal display device can be thinned. When used as a protective film for a polarizing film, the optical compensation film of the present invention has an in-plane slow axis orthogonal to the transport direction of the laminate of the support and the optically anisotropic layer in the production process. Preferably in the direction.
[Polarizer]
The polarizing plate of the present invention has the above-described optical compensation film of the present invention and a polarizing film. The polarizing plate generally comprises a polarizing film and a pair of protective films that sandwich the polarizing film. Although at least one of the pair of protective films is preferably the optical compensation film of the present invention, an optical compensation film may be further bonded to the surface of the protective film. Examples of the polarizing film include an iodine polarizing film, a dye polarizing film using a dichroic dye, and a polyene polarizing film. The iodine polarizing film and the dye polarizing film are generally produced using a polyvinyl alcohol film. The kind of protective film is not particularly limited, and cellulose esters such as cellulose acetate, cellulose acetate butyrate, and cellulose propionate, polycarbonate, polyolefin, polystyrene, polyester, and the like can be used. The transparent protective film is usually supplied in a roll form, and it is preferable that the transparent protective film is continuously bonded to the long polarizing film so that the longitudinal (MD) direction is coincident. Here, the orientation axis (slow axis) of the protective film may be any direction. Further, the angle between the slow axis (alignment axis) of the protective film and the absorption axis (stretching axis) of the polarizing film is not particularly limited, and can be appropriately set according to the purpose of the polarizing plate.

The polarizing film and the protective film may be bonded together with an aqueous adhesive. The adhesive solvent in the water-based adhesive is dried by diffusing in the protective film. The higher the moisture permeability of the protective film, the faster the drying and the higher the productivity. However, if the protective film is too high, the moisture will enter the polarizing film due to the usage environment (high humidity) of the liquid crystal display device. The performance drops. The moisture permeability of the optical compensation film is determined by the thickness, free volume or hydrophilicity / hydrophobicity of the polymer film (and polymerizable liquid crystal compound). The moisture permeability of the protective film for the polarizing plate is preferably in the range of 100 to 1000 (g / m ² ) / 24 hrs, and more preferably in the range of 300 to 700 (g / m ² ) / 24 hrs.

  In the present invention, for the purpose of reducing the thickness or the like, one of the protective films of the polarizing film may also serve as the support for the optically anisotropic layer, or may be the optical compensation film itself. The optical compensation film and the polarizing film are preferably subjected to a fixing treatment from the viewpoint of preventing the optical axis from shifting and preventing foreign matters such as dust from entering. An appropriate method such as an adhesive method through a transparent adhesive layer can be applied to the fixed lamination. There is no particular limitation on the type of the adhesive and the like, and from the viewpoint of preventing changes in the optical properties of the constituent members, those that do not require a high-temperature process during curing or drying are preferable, and a long-time curing process is preferable. And those that do not require drying time. From such a viewpoint, a hydrophilic polymer adhesive or a pressure-sensitive adhesive layer is preferably used.

  Appropriate functional layers such as a protective film for various purposes such as water resistance according to the above protective film, an antireflection layer and / or an antiglare treatment layer for the purpose of preventing surface reflection, etc. on one or both sides of the polarizing film You may use the polarizing plate which formed. The antireflection layer can be suitably formed, for example, as a light interference film such as a fluorine polymer coating layer or a multilayer metal vapor deposition film. The antiglare layer is also formed by an appropriate method that diffuses the surface reflected light, for example, by providing a fine uneven structure on the surface by an appropriate method such as a resin coating layer containing fine particles, embossing, sandblasting or etching. can do.

  In addition, as said microparticles | fine-particles, inorganic type which may have electroconductivity, such as silica, calcium oxide with an average particle diameter of 0.5-20 micrometers, an alumina, a titania, a zirconia, a tin oxide, an indium oxide, a cadmium oxide, an antimony oxide, for example One kind or two or more kinds of fine particles, cross-linked or non-cross-linked organic fine particles made of a suitable polymer such as polymethyl methacrylate and polyurethane can be used. The above-mentioned adhesive layer or pressure-sensitive adhesive layer may contain such fine particles and exhibit light diffusibility.

  The polarizing plate of the present invention preferably has optical properties and durability (storability in the short term and long term) equivalent to or better than those of a commercially available super high contrast product (for example, HLC2-5618 manufactured by Sanlitz Co., Ltd.). . Specifically, the visible light transmittance is 42.5% or more, and the degree of polarization √ {(Tp−Tc) / (Tp + Tc)} ≧ 0.9995 (where Tp is parallel transmittance and Tc is orthogonal transmittance) The rate of change of the light transmittance before and after being left for 500 hours in a 60 ° C., 90% humidity RH atmosphere and for 500 hours in a 80 ° C. dry atmosphere is 3% or less based on the absolute value. Is preferably 1% or less, and the rate of change in the degree of polarization is preferably 1% or less, more preferably 0.1% or less, based on the absolute value.

[Liquid Crystal Display]
The liquid crystal display device of the present invention is a liquid crystal display device having at least one of the optical compensation film of the present invention, the polarizing plate of the present invention, and the optically anisotropic layer transferred by the transfer material of the present invention. The display mode of the liquid crystal display device of the present invention is not particularly limited, but the VA mode is preferable. The liquid crystal display device of the present invention is effective not only in the display mode but also in an aspect applied to the STN mode, TN mode, and OCB mode.

[VA mode liquid crystal cell]
In the present invention, the liquid crystal cell is preferably in a vertically aligned mode (VA mode). The VA mode liquid crystal cell is formed by sealing liquid crystal molecules having negative dielectric anisotropy between upper and lower substrates whose opposite surfaces are rubbed. For example, by using liquid crystal molecules having Δn = 0.0813 and Δε = −4.6, a director indicating the alignment direction of the liquid crystal molecules, that is, a liquid crystal cell having a so-called tilt angle of about 89 ° can be manufactured. At this time, the thickness d of the liquid crystal layer can be about 3.5 μm. The brightness at the time of white display changes depending on the magnitude of the product Δn · d of the thickness d (nm) of the liquid crystal layer and the refractive index anisotropy Δn. In order to obtain the maximum brightness, the thickness d of the liquid crystal layer is preferably in the range of 2 to 5 μm (2000 to 5000 nm), and Δn is in the range of 0.060 to 0.085.

  Transparent electrodes are formed inside the upper and lower substrates of the liquid crystal cell, but in a non-driving state where no driving voltage is applied to the electrodes, the liquid crystal molecules in the liquid crystal layer are aligned approximately perpendicular to the substrate surface, resulting in liquid crystals The polarization state of the light passing through the panel hardly changes. Since the absorption axis of the upper polarizing plate of the liquid crystal cell and the absorption axis of the lower polarizing plate are substantially orthogonal, light does not pass through the polarizing plate. In other words, in the VA mode liquid crystal display device, an ideal black display can be realized in the non-driven state. On the other hand, in the driving state, the liquid crystal molecules are inclined in a direction parallel to the substrate surface, and the light passing through the liquid crystal panel changes the polarization state by the inclined liquid crystal molecules and passes through the polarizing plate.

  Up to this point, since an electric field is applied between the upper and lower substrates, an example using a liquid crystal material having a negative dielectric anisotropy in which liquid crystal molecules respond perpendicularly to the electric field direction has been shown. In the case where the liquid crystal material is disposed on the substrate and an electric field is applied in a lateral direction parallel to the substrate surface, a liquid crystal material having a positive dielectric anisotropy can be used.

  The characteristics of the VA mode are high-speed response and high contrast. However, there is a problem that the contrast is high in the front but decreases in the oblique direction. Since the liquid crystal molecules are aligned perpendicular to the substrate surface during black display, when viewed from the front, there is almost no birefringence of the liquid crystal molecules, so the transmittance is low and high contrast can be obtained. However, when observed obliquely, birefringence occurs in the liquid crystalline molecules. Furthermore, the crossing angle of the upper and lower polarizing plate absorption axes is 90 ° perpendicular to the front, but is greater than 90 ° when viewed from an oblique direction. Due to these two factors, leakage light tends to occur in the oblique direction, and the contrast tends to decrease. In the present invention, the optical anisotropic film transferred from the transfer material of the present invention by disposing the optical compensation film of the present invention between the liquid crystal cell and the polarizing plate, using the polarizing plate of the present invention, and / or This problem can be solved by including at least one conductive layer (preferably included in the liquid crystal cell).

  In the VA mode, liquid crystal molecules are tilted during white display, but the birefringence of the liquid crystal molecules when viewed from an oblique direction is different between the tilt direction and the opposite direction, resulting in differences in luminance and color tone. . In order to solve this, the liquid crystal cell is preferably multi-domain. Multi-domain refers to a structure in which a plurality of regions having different alignment states are formed in one pixel. For example, in a multi-domain VA mode liquid crystal cell, a plurality of regions in which tilt angles of liquid crystal molecules are different from each other when an electric field is applied exist in one pixel. In a multi-domain VA mode liquid crystal cell, the tilt angle of liquid crystal molecules due to application of an electric field can be averaged for each pixel, whereby the viewing angle characteristics can be averaged. Dividing the orientation within one pixel can be achieved by providing a slit in the electrode, providing a protrusion, changing the direction of the electric field, or biasing the electric field density. In order to obtain a uniform viewing angle in all directions, the number of divisions may be increased. However, since the transmittance during white display is reduced, four divisions are preferable.

  In a VA mode liquid crystal display device, the addition of a chiral agent generally used in a Twisted Nematic mode (TN mode) liquid crystal display device is rarely used to degrade the dynamic response characteristics. Sometimes added to reduce. At the boundary of the alignment division, the liquid crystal molecules are difficult to respond. For this reason, in normally black display, since black display is maintained, a decrease in luminance becomes a problem. Adding a chiral agent to the liquid crystal material contributes to reducing the boundary region.

  The features of the present invention will be described more specifically with reference to examples and comparative examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.

(Preparation of transparent support S-1)
A commercial cellulose acetate film, Fujitac TD80UF (Fuji Photo Film Co., Ltd., Re = 3 nm, Rth = 50 nm) was used as the transparent support S-1.

(Preparation of coating liquid AL-1 for alignment layer)
The following composition was prepared, filtered through a polypropylene filter having a pore size of 30 μm, and used as an alignment layer coating liquid AL-1. As the modified polyvinyl alcohol, one described in JP-A-9-152509 was used.
───────────────────────────────────
Coating liquid composition for alignment layer (% by mass)
─────────────────────────────────――
Modified polyvinyl alcohol AL-1-1 4.01
Water 72.89
Methanol 22.83
Glutaraldehyde (crosslinking agent) 0.20
Citric acid 0.008
Citric acid monoethyl ester 0.029
Citric acid diethyl ester 0.027
Citric acid triethyl ester 0.006
───────────────────────────────────

(Preparation of coating liquid AL-2 for intermediate layer / alignment layer)
The following composition was prepared, filtered through a polypropylene filter having a pore size of 30 μm, and used as a peeling intermediate layer / alignment layer coating solution AL-2.
──────────────────────────────────――
Coating solution composition for intermediate layer / alignment layer (% by mass)
──────────────────────────────────――
Polyvinyl alcohol (PVA205, manufactured by Kuraray Co., Ltd.) 3.21
Polyvinylpyrrolidone (Luvitec K30, manufactured by BASF) 1.48
Distilled water 52.1
Methanol 43.21
──────────────────────────────────――

(Preparation of coating liquid LC-1 for optically anisotropic layer)
After the following composition was prepared, it was filtered through a polypropylene filter having a pore size of 0.2 μm and used as a coating liquid LC-1 for an optically anisotropic layer. LC-1-1 was synthesized by the method described in EP13885538A1, page 21.
───────────────────────────────────
Coating liquid composition for optically anisotropic layer (% by mass)
─────────────────────────────────――
Bar-shaped liquid crystal (Paliocolor LC242, BASF Japan) 26.66
Chiral agent (Paliocolor LC756, BASF Japan) 3.10
Photopolymerization initiator (LC-1-1) 1.24
Methyl ethyl ketone 69.00
───────────────────────────────────

(Preparation of coating liquid CU-1 for thermoplastic resin layer)
The following composition was prepared, filtered through a polypropylene filter having a pore size of 30 μm, and used as a coating liquid CU-1 for a thermoplastic resin layer.
──────────────────────────────────――
Coating liquid composition for thermoplastic resin layer (% by mass)
──────────────────────────────────――
Methyl methacrylate / 2-ethylhexyl acrylate /
Benzyl methacrylate / methacrylic acid copolymer (copolymerization composition ratio (molar ratio) = 55/30/10/5,
(Weight average molecular weight = 100,000, Tg≈70 ° C.)
5.89
Styrene / acrylic acid copolymer (copolymerization composition ratio (molar ratio) = 65/35, weight average molecular weight = 10,000, Tg≈100 ° C.)
13.74
BPE-500 (manufactured by Shin-Nakamura Chemical Co., Ltd.) 9.20
Megafuck F-780-F (manufactured by Dainippon Ink & Chemicals, Inc.) 0.55
Methanol 11.22
Propylene glycol monomethyl ether acetate 6.43
Methyl ethyl ketone 52.97
──────────────────────────────────――

(Preparation of coating liquid PP-1 for photosensitive resin layer)
After preparing the following composition, it filtered with the polypropylene filter with the hole diameter of 0.2 micrometer, and used as coating liquid PP-1 for photosensitive resin layers.
──────────────────────────────────――
Composition of coating solution for photosensitive resin layer (% by mass)
──────────────────────────────────――
Random copolymer of benzyl methacrylate / methacrylic acid = 72/28 molar ratio (weight average molecular weight 37,000) 5.0
Random copolymer of benzyl methacrylate / methacrylic acid = 78/22 molar ratio (weight average molecular weight 40,000) 2.45
KAYARAD DPHA (Nippon Kayaku Co., Ltd.) 3.2
Radical polymerization initiator (Irgacure 907, manufactured by Ciba Specialty Chemicals) 0.75
Sensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.) 0.25
Cationic polymerization initiator (diphenyliodonium hexafluorophosphate, manufactured by Tokyo Chemical Industry) 0.1
Propylene glycol monomethyl ether acetate 27.0
Methyl ethyl ketone 53.0
Cyclohexanone 9.1
Megafuck F-176PF (Dainippon Ink Co., Ltd.) 0.05
──────────────────────────────────――

(Polarized UV irradiation device POLUV-1)
A microwave emission type ultraviolet irradiation device (Light Hammer 10, 240 W / cm, manufactured by Fusion UV Systems) equipped with D-Bulb having a strong emission spectrum at 350 to 400 nm as a UV light source was separated from the irradiation surface by 3 cm. At the position, a wire grid polarizing filter (ProFlux PPL02 (high transmittance type), manufactured by Moxtek) was installed to produce a polarized UV irradiation apparatus. The maximum illuminance of this device was 400 mW / cm ² .

(One-side saponification treatment of cellulose ester film)
The cellulose ester film was passed through a dielectric heating roll having a temperature of 60 ° C. and the film surface temperature was raised to 40 ° C., and then an alkali solution having the composition shown below was applied at 14 ml / m ² using a bar coater. Then, after retaining for 10 seconds under a steam far infrared heater (manufactured by Noritake Co., Ltd.) heated to 110 ° C., 3 ml / m ^{2 of} pure water was applied using the same bar coater. The film temperature at this time was 40 degreeC. Next, washing with a fountain coater and draining with an air knife were repeated three times, and then the sample was retained in a drying zone at 70 ° C. for 2 seconds and dried.

[Examples 1 to 4, Comparative Example 1]
After saponifying one side of the transparent support S-1 using the above-described one-side saponification method, the coating liquid AL-1 for alignment layer is applied thereon with a # 14 wire bar coater, and warm air at 60 ° C. For 60 seconds and then with warm air at 90 ° C. for 150 seconds to form an alignment layer having a thickness of 1.0 μm. Subsequently, after rubbing the formed alignment layer in the transport direction (MD direction) of the transparent support, the coating liquid LC-1 for optically anisotropic layer was applied thereon with a # 8 wire bar coater. Then, the film surface temperature was 95 ° C. for 2 minutes by heat drying to form an optically anisotropic layer having a uniform liquid crystal phase. Further, immediately after the aging, a pre-process capable of controlling the oxygen concentration and the nitrogen temperature with respect to the optically anisotropic layer, the oxygen concentration and the nitrogen temperature can be controlled, and 400 mW / cm ² can be obtained by the polarized UV irradiation apparatus POLUV-1. The optically anisotropic layer was fixed (cured) by passing through a post-process capable of irradiating ultraviolet rays with illuminance. The conditions of oxygen concentration and nitrogen temperature in the pre-process and post-process were irradiated with ultraviolet rays in the pattern shown in Table 1, and optical compensation films of Examples 1 to 4 and Comparative Example 1 were produced. The optically anisotropic layer did not show a liquid crystal phase even when heated after fixing. The thickness of the optically anisotropic layer was 3.4 μm.

  In addition, the isotropic phase transition temperature of the rod-shaped liquid crystal (Paliocolor LC242, BASF Japan) used in LC-1 is 100.2 ° C.

(Dry adhesion)
The presence or absence of peeling was visually observed by a cross-cut method, and the following three-stage evaluation was performed.
◯: No peeling was observed
Δ: 10% or more peeling was observed
X: 50% peeled off

(Wet adhesion)
A 24 × 36 mm sample was immersed in hot water of 60 ° C. for 5 minutes, and the presence or absence of peeling was visually observed, and the following three-stage evaluation was performed.
◯: No peeling was observed
Δ: 10% or more peeling was observed
X: 50% peeled off

(Phase difference measurement)
Retardation Re (40) and Re (−40) when a sample is tilted by ± 40 degrees with KOBRA 21ADH (manufactured by Oji Scientific Instruments Co., Ltd.) and front retardation Re at 589 nm and the slow axis as the rotation axis. It was measured. The retardation of the optically anisotropic layer was determined by subtracting the retardation of the support at each angle from the retardation of the entire optical compensation film at each angle.

  Table 3 shows adhesion evaluation results and phase difference measurement results of Examples 1 to 4 and Comparative Example 1.

(Preparation of polarizing plate with optical compensation film)
The optical compensation film of Example 1 of the present invention and the commercially available Fujitac TD80UF (Fuji Photo Film Co., Ltd., Re = 3 nm, Rth = 50 nm) were added to a 1.5 mol / L sodium hydroxide aqueous solution at 55 ° C. Immerse for a minute. Subsequently, it was washed in a water bath at room temperature and neutralized at 30 ° C. with 0.05 mol / L sulfuric acid. This was washed again in a room temperature water bath and further dried with hot air at 100 ° C. Thereafter, washing with water and neutralization treatment were performed, and the two saponified films were attached to both surfaces of the polarizing film with a roll-to-roll using a polyvinyl alcohol adhesive as a protective film for the polarizing plate. A body-type polarizing plate was produced.

[Example 5]
(Production of VA-LCD liquid crystal display device)
Strip the upper and lower polarizing plates of a commercially available VA-LCD (SyncMaster 173P, manufactured by Samsung Electronics Co., Ltd.), the upper side is a normal polarizing plate, the lower side is a polarizing plate with an optical compensation film of Example 1 of the present invention, The liquid crystal display device of the present invention was prepared by pasting with an adhesive such that the optically anisotropic layer was on the liquid crystal cell substrate glass surface. FIG. 7 shows a schematic cross-sectional view of the manufactured liquid crystal display device together with the angular relationship of the optical axes of the respective layers. In FIG. 7, 41 is a polarizing layer, 42 is a transparent support, 43 is an orientation layer, 44 is an optical anisotropic layer (an optical compensation film is composed of 41 to 44), 45 is a polarizing plate protective film, 46 is A glass substrate for a liquid crystal cell, 47 is a liquid crystal cell, and 48 is an adhesive layer. Further, the arrow in the polarizing layer 41 indicates the direction of the absorption axis, the arrow in the optically anisotropic layer 44 or its support 44 and the protective film 45 indicates the direction of the slow axis, and the circle indicates the direction of the arrow relative to the paper surface. Indicates the line direction.

(Evaluation of VA-LCD liquid crystal display device)
The viewing angle characteristics of the manufactured liquid crystal display device were measured with a viewing angle measuring device (EZ Contrast 160D, manufactured by ELDIM). Furthermore, it evaluated also visually about 45 degree | times diagonally especially. FIG. 8 shows the contrast characteristics of Example 4 by EZ Contrast, and Table 3 shows the visual evaluation results.

[Example 6 Production of transfer material]
On the roll-shaped polyethylene terephthalate film temporary support body of thickness 75micrometer, the coating liquid CU-1 for thermoplastic resin layers was apply | coated and dried using the slit-shaped nozzle. Next, the intermediate layer / alignment layer coating solution AL-1 was applied and dried. The film thickness of the thermoplastic resin layer was 14.6 μm, and the alignment layer was 1.6 μm. Subsequently, after rubbing the formed alignment layer, the optically anisotropic layer coating solution is coated thereon with a # 8 wire bar coater, and the film surface temperature is 95 ° C. for 2 minutes by heating and ripening to be uniform. A layer having a liquid crystal phase was formed. Further, immediately after aging, this layer was irradiated with polarized UV using POLUV-1 so that the transmission axis of the polarizing plate was in the TD direction of the transparent support in a nitrogen atmosphere having an oxygen concentration of 0.3% or less. (Illuminance 200 mW / cm ² , irradiation amount 200 mJ / cm ² ) to fix the optically anisotropic layer, and form an optically anisotropic layer having a thickness of 3.4 μm. Finally, the photosensitive resin composition PP-1 was applied and dried to prepare a photosensitive resin transfer material which is Example 6 of the present invention.

Using a laminator (manufactured by Hitachi Industries, Ltd. (Lamic II type)) as the photosensitive resin transfer material, a rubber roller temperature of 130 ° C., a linear pressure of 100 N / cm, and a conveyance speed on the substrate heated at 100 ° C. for 2 minutes. After laminating at 2.2 m / min and peeling off the protective film, the entire surface was exposed with an ultra high pressure mercury lamp at an exposure amount of 50 mJ / cm ² and further baked at 240 ° C. for 2 hours to obtain the glass substrate for VA-LCD of the present invention. Produced.
Next, FUJIFILM RESEARCH & DEVELOPMENT No. 44 (1999), page 25, the Transer system (manufactured by Fuji Photo Film Co., Ltd.) was used to form a black matrix and R, G, B color filters on the glass substrate.

(Formation of transparent electrode)
A transparent electrode film was formed on the color filter produced above by sputtering of ITO.

(Preparation of photosensitive transfer material for protrusions)
A thermoplastic resin layer coating solution TP-1 was applied onto a 75 μm thick polyethylene terephthalate film temporary support and dried to provide a thermoplastic resin layer having a dry film thickness of 15 μm.
Next, the intermediate layer / alignment layer coating solution AL-1 was applied on the thermoplastic resin layer and dried to provide an intermediate layer having a dry film thickness of 1.6 μm.
On the said intermediate | middle layer, the coating liquid which consists of the following prescription was apply | coated and dried, and the photosensitive resin layer for liquid crystal orientation control protrusions with a dry film thickness of 2.0 micrometers was provided.
──────────────────────────────────――
Protrusion coating composition (%)
──────────────────────────────────――
FH-2413F (manufactured by FUJIFILM Arch Corporation) 53.3
Methyl ethyl ketone 46.66
Mega Fuck F-176PF 0.04
──────────────────────────────────――
Further, a 12 μm-thick polypropylene film is attached to the surface of the photosensitive resin layer as a cover film, and a thermoplastic resin layer, an intermediate layer, a photosensitive resin layer, and a cover film are laminated in this order on the temporary support. A transfer material was prepared.

(Forming protrusions)
The cover film is peeled off from the projection transfer material produced above, and the surface of the photosensitive resin layer and the surface of the color filter side substrate on which the ITO film is provided are overlapped to form a laminator (Hitachi Industry Co., Ltd.). Using a product made by Izu (Lamic II type), bonding was performed under the conditions of a linear pressure of 100 N / cm, a temperature of 130 ° C., and a conveying speed of 2.2 m / min. Thereafter, only the temporary support of the transfer material was peeled and removed at the interface with the thermoplastic resin layer. In this state, the photosensitive resin layer, the intermediate layer, and the thermoplastic resin layer are laminated in this order on the color filter side substrate.
Next, a proximity exposure machine is placed above the outermost thermoplastic resin layer so that the photomask is at a distance of 100 μm from the surface of the photosensitive resin layer, and an ultrahigh pressure mercury lamp is passed through the photomask. Proximity exposure was performed at an irradiation energy of 70 mJ / cm ² . Thereafter, a 1% triethanolamine aqueous solution was sprayed onto the substrate at 30 ° C. for 30 seconds with a shower type developing device to dissolve and remove the thermoplastic resin layer and the intermediate layer. At this stage, the photosensitive resin layer was not substantially developed.
Subsequently, 0.085 mol / L sodium carbonate, 0.085 mol / L sodium hydrogen carbonate, and 1% sodium dibutylnaphthalenesulfonate aqueous solution were developed while spraying onto the substrate at 33 ° C. for 30 seconds using a shower type developing device. Then, unnecessary portions (uncured portions) of the photosensitive resin layer were developed and removed. Then, a protrusion made of a photosensitive resin layer patterned into a desired shape was formed on the color filter side substrate. Next, the color filter side substrate on which the protrusions are formed is baked at 240 ° C. for 50 minutes to form a liquid crystal alignment control protrusion having a height of 1.5 μm and a vertical cross-sectional shape on the color filter side substrate. Could be formed.

(Formation of alignment layer)
Further, a polyimide alignment film was provided thereon. An epoxy resin sealant containing spacer particles is printed at a position corresponding to the outer frame of the black matrix provided around the pixel group of the color filter, and the color filter substrate is attached to the counter substrate with a pressure of 10 kg / cm. Combined. Next, the bonded glass substrate was heat-treated at 150 ° C. for 90 minutes to cure the sealing agent, thereby obtaining a laminate of two glass substrates. This glass substrate laminate was degassed under vacuum, then returned to atmospheric pressure, and liquid crystal was injected into the gap between the two glass substrates to obtain a liquid crystal cell. Polarizing plates HLC2-2518 made by Sanritz Co., Ltd. were attached to both surfaces of this liquid crystal cell.

(Production of Example VA-LCD)
As a cold-cathode tube backlight for a color liquid crystal display device, a phosphor obtained by mixing BaMg ₂ Al ₁₆ O ₂₇ : Eu, Mn and LaPO ₄ : Ce, Tb at a mass ratio of 50:50 is green (G), Y ₂ O ₃ : Eu was red (R) and BaMgAl ₁₀ O ₁₇ : Eu was blue (B) to produce a white three-wavelength fluorescent lamp having an arbitrary color tone. A liquid crystal cell provided with the above polarizing plate was placed on the backlight to produce a VA-LCD.

(Evaluation of VA-LCD)
Light leakage at the corners of the LCD, particularly at the corners, during black display (no voltage applied) of the manufactured liquid crystal display device was first observed visually at room temperature, and then allowed to stand for 48 hours under constant temperature and humidity conditions of 40 ° C. and 90% RH. And then observed again. The results are shown in Table 1.

  According to the present invention, it is possible to provide a VA mode liquid crystal display device having excellent viewing angle characteristics.

It is a schematic sectional drawing of an example of the optical compensation film of this invention. It is a schematic sectional drawing of the example of the polarizing plate of this invention. It is a schematic sectional drawing of the example of the transfer material of this invention. It is a schematic sectional drawing of the example of the board | substrate for liquid crystal cells produced using the transfer material of this invention. It is a schematic sectional drawing of an example of the liquid crystal display device of this invention. It is a schematic sectional drawing of the example of the liquid crystal display device containing the optically anisotropic layer transcribe | transferred from the transfer material of this invention. FIG. 10 is a schematic cross-sectional view showing the layer configuration of the liquid crystal display device manufactured in Example 5 together with the direction of the optical axis in the layer. FIG. 10 is a graph showing contrast characteristics of the liquid crystal display device manufactured in Example 5.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Support body 12 Optically anisotropic layer 13 Orientation layer 14 Photosensitive resin layer 15 Cushion layer 16 Protective layer 21 Polarizing layer (polarizing film)
22, 23 Protective film 24 Functional layer 25 such as λ / 4 plate, antireflection film, etc. Transparent electrode layer 26 Alignment layer 27 Optical compensation layer 27 ′ Patterned optical compensation layer 28 Color filter layer 29 Black matrix layer 30 Support ( (It is also a transfer target)
31 Liquid crystal layer 32 TFT layer 33 Polarizing layer 34 Protective film 35 Protective film (may be an optical compensation film)
36 Polarizing plate 37 Liquid crystal cell 41 Polarizing layer 42 Transparent support 43 Orientation layer 44 Optical anisotropic layer 45 Polarizing plate protective film 46 Glass substrate for liquid crystal cell 47 Liquid crystal cell 48 Adhesive 51 Cold cathode tube 52 Reflective sheet 53 Light guide plate 54 Light control film 55 such as brightness enhancement film, diffusion film, etc. Liquid crystal cell 56 Lower polarizing plate 57 Upper polarizing plate

Claims (15)

A step of forming an optically anisotropic layer by applying and drying a composition for forming an optically anisotropic layer containing a liquid crystalline compound having an isotropic phase transition temperature of T ° C. having at least one polymerizable group on a support When,
Curing the optically anisotropic layer by irradiating the optically anisotropic layer with ultraviolet rays at least once at 40 ° C. or higher and T ° C. or lower and an oxygen concentration of 10% by volume or lower. A method for producing an anisotropic film. The method according to claim 1, wherein in the curing step, the oxygen concentration at the time of ultraviolet irradiation is 3% by volume or less. The said hardening process is implemented to the laminated body which has the optically anisotropic layer before hardening on a support body simultaneously or continuously with the conveyance process which conveys the inside of an atmosphere with an oxygen concentration of 10 volume% or less. The method described. The method according to claim 3, wherein in the transporting step, the laminate is transported in an atmosphere of 40 ° C. or higher and T ° C. or lower. 5. The oxygen concentration in the atmosphere is maintained in the above range by blowing out an oxygen-blocking gas heated to 40 ° C. or higher and T ° C. or lower in the curing step and / or the conveying step. The method described in 1. The method according to claim 5, wherein the oxygen barrier gas is an inert gas. The method according to claim 1, wherein part or all of the ultraviolet light is polarized. The method according to claim 1, wherein the cured optically anisotropic layer has a retardation with a front retardation (Re) which is not zero. The method according to claim 3, wherein an in-plane slow axis of the optical film is in a direction orthogonal to the direction of conveyance. An optically anisotropic film produced by the method according to claim 1. The optically anisotropic film according to claim 10 used as an optical compensation film. 12. A polarizing plate comprising a polarizing film and a pair of protective films protecting the polarizing film, wherein at least one of the pair of protective films is the optically anisotropic film according to claim 10 or 11. The transfer material which has a photosensitive resin layer on the optically anisotropic layer of the optically anisotropic film of any one of Claims 1-10. 13. A liquid crystal display device comprising a liquid crystal cell having a pair of substrates and a liquid crystal layer sandwiched between the substrate, and the polarizing plate according to claim 12 and / or a pair of the liquid crystal cells on the outside of the liquid crystal cell. A liquid crystal display device having an optically anisotropic layer transferred from the transfer material according to claim 13 on at least one surface of the substrate. The liquid crystal display device according to claim 14, wherein the display mode is a VA mode.

Images