JP2007114739A - Optical anisotropic polymer film, polarizing film, manufacturing method thereof and application use thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optically anisotropic polymer film that is superior in manufacturing adaptability and improved in stability, and to provide a manufacturing method of the optical anisotropic polymer film. <P>SOLUTION: The optical anisotropic polymer film is obtained, by having a polymer film comprising at least one photoreactive compound and at least one non-liquid crystalline polymer irradiated with light, thereby inducing or changing the optical anisotropy of the polymer. The manufacturing method of the optical anisotropic polymer film includes a photoirradiation process of irradiating a polymer film, comprising at least one photoreactive compound and at least one non-liquid crystalline polymer with light, thereby controlling the optical anisotropy of the polymer film. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a polymer film with controlled optical anisotropy, a production method useful for the production thereof, and a polarizing plate, an image display element, and a polarizing film using the polymer film.

  CRT (Cathode Ray Tube) has been mainly used so far as an image 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 have been widely used instead of CRTs because of their thinness, light weight, and low power consumption. Various polymer films have been used for various applications in these image display devices. A liquid crystal display device generally has a liquid crystal cell and a polarizing plate. A polarizing plate usually comprises 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. In addition, optical compensation films and retardation films are often used to improve the contrast of image display devices and expand the viewing angle range. As such an optical compensation film or retardation film, a stretched film having refractive index anisotropy or a film obtained by aligning and polymerizing a liquid crystal compound is used.

  In recent years, with respect to polymer films used in these image display devices, more precise control of refractive index anisotropy is required in order to further improve the viewing angle characteristics and contrast of the image display devices. At the same time, reducing manufacturing costs is an issue in terms of manufacturing. Under such circumstances, the stretched film has a problem that the stretching direction during production is limited and it is difficult to precisely control the refractive index anisotropy. On the other hand, a film obtained by aligning and polymerizing a liquid crystal compound generally aligns the liquid crystal compound using an alignment film or an alignment substrate. Therefore, for example, since it is necessary to separately manufacture an alignment film and an alignment substrate, there is a problem that the manufacturing process becomes complicated. Furthermore, also from the viewpoint of precise control of refractive index anisotropy, the refractive index anisotropy largely depends on the alignment film or the alignment substrate.

  Therefore, in recent years, a method for producing a film having refractive index anisotropy that does not require an alignment film or an alignment substrate has been developed. For example, there is a method for producing a film having refractive index anisotropy by irradiating a film made of a polymer compound having a photoisomerizable group such as azobenzene or a film made of the polymer compound and a liquid crystal compound from an oblique direction. Known (for example, Patent Documents 1 and 2). However, the film produced in this manner has a problem in terms of stability because the orientation of the photoisomerization group and the orientation of the liquid crystal compound are not fixed.

  Next, the film-like molded product of a mixture composed of a liquid crystal monomer having a crosslinkable group and a photoreactive monomer (photo-alignment monomer) is irradiated with polarized light, photo-aligned with the liquid crystal monomer, and then again irradiated with light. A method for producing a film having refractive index anisotropy in which the liquid crystal monomer is crosslinked to fix its alignment state is known (for example, Patent Document 3). However, in this method, a part of the liquid crystal monomer is polymerized at the time of irradiation with polarized light, and there may be a problem in the optical properties of the obtained film. In order to solve such a problem, a method of reacting a photoreactive monomer in a state in which the polymerization reaction of the liquid crystal monomer is suppressed at the time of polarized light irradiation is adopted. It is said that there is a problem that the obtained film is not sufficiently crosslinked and easily damaged.

  In order to solve the above problems, a film-like molded product of a mixture of a liquid crystal polymer and a photoreactive compound is prepared, and the film-like molded product is irradiated with light to change the molecular structure of the photoreactive compound. The method for producing an optical film, wherein the liquid crystal polymer is aligned at a temperature higher than the temperature at which the liquid crystal polymer exhibits a liquid crystal state, and then the liquid crystal polymer is cooled to a temperature lower than the temperature at which the liquid crystal polymer exhibits a liquid crystal state, Has been reported (for example, Patent Document 4). However, the optical film produced by such a method has a problem that the stability to heat is weak and the refractive index anisotropy is reduced and disappears when heated to a temperature higher than the liquid crystal state.

  Next, polarizing plates used in liquid crystal display devices (LCD) and the like are two-colored, i.e., iodine-based polarizing plates obtained by stretching polyvinyl alcohol (PVA) adsorbed with iodine complexes in a uniaxial direction, and PVA stretching in a uniaxial direction. Manufactured by a dye-based polarizing plate on which a functional dye is adsorbed. Iodine polarizing plates have excellent polarization and transmittance, and are used in most high contrast LCDs such as notebook computers, LCD monitors, and liquid crystal televisions. On the other hand, the dye-type polarizing plate is inferior in iodine to the degree of polarization but has high weather resistance, and is often used for outdoor applications such as in-vehicle LCDs and polarized sunglasses.

  However, iodine-based polarizing plates and dye-based polarizing plates have a structure that is sandwiched between two protective films such as triacetyl cellulose (TAC) film because the uniaxially stretched PVA is easily torn, and is very thick. In addition, in principle, an expensive non-birefringent film or a low birefringent film must be used as the protective film, which has a problem that the cost increases. Furthermore, these polarizing plates have a problem that it is difficult in principle to form a pattern or a specific shape such as a curved surface.

In addition to the above, polarizing elements or polarizing plates based on a combination of a photo-alignment film and a dichroic dye have been proposed (Patent Documents 5 and 6). These polarizing elements and polarizing plates can form complicated patterns and curved shapes by patterning the photo-alignment film with light.
However, since it has an expensive photo-alignment layer in addition to the polarizing layer, there is a problem that the cost is increased. Moreover, the manufacturing process consists of a photo-alignment film coating process, a photo-alignment treatment process by light irradiation, a dichroic dye coating process, a dichroic dye alignment process, etc., and is very long and complicated. The manufacturing cost is also high. Furthermore, it can be applied only to a dichroic dye that is aligned on the photo-alignment film.

  Furthermore, a polarizing element is also proposed in which a liquid crystal layer composed of a curable liquid crystal and a dichroic dye is formed on a support provided with an alignment layer, and the liquid crystal layer is cured (Patent Document 7). However, even in the polarizing element by this method, the problem of high cost is not necessarily improved due to the use of expensive curable liquid crystals and the complicated manufacturing process. Further, liquid crystal alignment is used for anisotropic alignment of the dichroic dye, and light scattering due to liquid crystal alignment disorder or fluctuation becomes a problem.

Japanese Patent No. 3315476 Japanese Patent No. 3312063 JP 2005-517605 Gazette JP 2005-62765 A Japanese Patent Laid-Open No. 7-261024 JP-A-9-197125 JP 2001-330726 A

An object of the present invention is to provide an optically anisotropic polymer film excellent in production suitability and improved in storage stability, and a production method useful for the production thereof. The further subject of this invention is providing the polarizing plate and image display element which used this optically anisotropic polymer film.
Another object of the present invention is a polarizing film that does not require a stretching operation of a polymer film, an expensive protective film or an alignment film, and can form a very fine polarizing pattern and can be manufactured at low cost by coating. And a manufacturing method thereof.

The object of the present invention has been achieved by the following [1] to [15].
[1] High optical anisotropy obtained by irradiating a polymer film containing at least one photoreactive compound and at least one non-liquid crystalline polymer, and expressing or changing optical anisotropy by light irradiation. Molecular film.
[2] The optically anisotropic polymer film of [1], wherein the photoreactive compound is a photoreactive compound having a polymerizable group.
[3] The optically anisotropic polymer film of [1] or [2], wherein the photoreactive compound is a photoreactive compound having liquid crystallinity.
[4] The optically anisotropic polymer film according to any one of [1] to [3], wherein the photoreactive compound is a cinnamic acid derivative or a coumarin derivative.
[5] The non-liquid crystalline polymer is a polyacrylate polymer, polymethacrylate polymer, polyvinyl alcohol polymer, polycarbonate polymer, polysulfone polymer, cellulose polymer, polyolefin polymer, or the like. The optically anisotropic polymer film according to any one of [1] to [4], which is a copolymer of the above polymer.
[6] The optically anisotropic polymer film according to any one of [1] to [5], wherein the polymer film is a polymer film stretched uniaxially or biaxially.

[7] The optically anisotropic polymer film according to any one of [1] to [6], further comprising an optically anisotropic layer containing a polymer of a liquid crystal composition containing at least one liquid crystal compound.
[8] The optically anisotropic polymer film according to any one of [1] to [7], which is used as an optical compensation film.
[9] A polarizing plate having at least a polarizing film and the optically anisotropic polymer film of any one of [1] to [8].
[10] An image display device having the optically anisotropic polymer film of any one of [1] to [8] or the polarizing plate of [9].
[11] A light irradiation step of irradiating a polymer film containing at least one photoreactive compound and at least one non-liquid crystalline polymer to control the optical anisotropy of the polymer film is included. A method for producing an optically anisotropic polymer film.
[12] The method according to [11], further comprising a stretching step of subjecting the polymer film to uniaxial or biaxial stretching before the light irradiation step.
[13] The method according to [11] or [12], wherein in the light irradiation step, light is irradiated from a direction inclined by θ ° (0 <θ <90) from a normal direction of the polymer film.
[14] The method according to any one of [11] to [13], wherein in the light irradiation step, the light to be irradiated is linearly polarized light.
[15] The method according to any one of [11] to [14], wherein in the light irradiation step, the light to be irradiated is ultraviolet light.
[16] Obtained by irradiating a polymer film containing at least one photoreactive compound having absorption in a wavelength range of 400 nm to 800 nm and at least one non-liquid crystalline polymer, and developing the polarization by irradiating polarized light. Polarizing film.
[17] The polarizing film according to [16], wherein the photoreactive compound is a dichroic photoreactive compound.
[18] The polarizing film according to [16], wherein the photoreactive compound is a photodegradable compound.
[19] Polarized light including a light irradiation step of irradiating linearly polarized light onto a polymer film containing at least one photoreactive compound and at least one non-liquid crystalline polymer to control the polarization property of the polymer film A method for producing a film.
[20] A color filter comprising the polarizing film according to [16].
[21] An image display device having the polarizing film of any one of [16] to [18] or the color filter according to [20].

In the present invention, since the optical anisotropy is controlled or adjusted by irradiating the photoreaction product of the photoreactive compound added to the non-liquid crystalline polymer with light, the conventional liquid crystalline monomer is used. Unlike the manufacturing method using a liquid crystalline polymer, the liquid crystal alignment process is not included, and the process is simplified and the cost is reduced. Moreover, a highly stable optically anisotropic polymer film can be obtained. Furthermore, since the polymer film used for the production thereof can arbitrarily control various optical properties, its retardation and wavelength dispersion by light, it is useful for use in an optical compensation film, a polarizing plate and an image display device. A high-quality optically anisotropic polymer film can be provided.
As another effect of the present invention, a polarizing element having an extremely fine polarization pattern can be provided at low cost.

Hereinafter, the present invention will be described in detail.
In the present specification, “to” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value.

  In this specification, Re (λ) represents in-plane retardation at a wavelength λ. Re (λ) can be measured by making light with a wavelength of λ nm incident using the Senarmon method. The Senalmon method is described in Hiroya Ashiya, “Introduction to Polarizing Microscopes for Polymer Materials”, Agne Technical Center (2001). Alternatively, it is measured by making light of wavelength λ nm incident in the film normal direction in KOBRA 31PRN or KOBRA WR (both manufactured by Oji Scientific Instruments).

[Optically anisotropic polymer film]
The present invention provides an optical anisotropy obtained by irradiating a polymer film containing at least one photoreactive compound and at least one non-liquid crystalline polymer, and expressing or changing the optical anisotropy by the light irradiation. The present invention relates to a polymer film. When the polymer film is irradiated with light, the photoreactive compound undergoes a photoreaction, thereby causing optical anisotropy to appear or change. As a result, the retardation of the polymer film can be arbitrarily controlled and the wavelength dispersibility can also be controlled. “Expression of optical anisotropy” refers to the optically isotropic polymer film. The term “change in optical anisotropy” refers to, for example, a change that increases or decreases the optical anisotropy of a polymer film, an in-plane slow axis. Various aspects, such as a change in which the direction changes, are included.

Hereinafter, various materials used for production of the optically anisotropic polymer film of the present invention will be described in detail.
[Photoreactive compound]
In the present invention, the photoreactive compound is, for example, a compound that causes at least one of a photoisomerization reaction, a photocyclization dimerization reaction, and a photolysis reaction by light irradiation. The photoreactive compound is preferably a compound that undergoes a photoisomerization reaction or photocyclization dimerization reaction upon irradiation with light, and a compound that undergoes a photocyclization dimerization reaction is particularly preferred. The photoreactive compound may be either a low molecular compound or a high molecular compound. In the case of a low molecular compound, the photoreactive compound preferably has liquid crystallinity. Further, the photoreactive compound preferably has at least one polymerizable group, and more preferably has a plurality of polymerizable groups.

  The photoreactive compound includes a compound that undergoes a photoisomerization reaction, that is, a compound that undergoes stereoisomerization or structural isomerization by the action of light. Photoisomerized compounds include azobenzene compounds (K. Ichimura et al., Langmuir, vol. 4, page 1214 (1988); K. Aoki et al., Langmuir, vol. 8, page 1007 (1992); Suzuki et al., Langmuir, vol.8, page 2601 (1992); K. Ichimura et al., Appl.Phys.Lett., Vol.63, No.4, page 449 (1993), N. Ishikiki, Langmu. vol. 9, page 3298 (1993); N. Ishizuki, Langmuir, vol. 9, page 857 (1993)), hydrazono-β-ketoester compounds (S. Yamamura et a , Liquid Crystals, vol. 13, No. 2, page 189 (1993)), stilbene compounds (Kunihiro Ichimura et al., Polymer Journal, Vol. 47, No. 10, p. 771 (1990)) and spiropyran compounds ( K. Ichimura et al., Chemistry Letters, page 1063 (1992); K. Ichimura et al., Thin Solid Films, vol. 235, page 101 (1993)). Among them, a photoisomerized compound containing a double bond structure consisting of C = C or N = N is preferred, and an azobenzene compound containing a double bond structure consisting of N = N is particularly preferred.

  The photoreactive compound includes a compound that undergoes a photocyclization dimerization reaction, that is, a compound that undergoes an addition reaction between two groups upon irradiation with light to cyclize. Photocyclized dimerization compounds include cinnamic acid derivatives (M. Schadt et al., J. Appl. Phys., Vol. 31, No. 7, page 2155 (1992)) and coumarin derivatives (M. Schadt et al. , Nature., Vol. 381, page 212 (1996)), chalcone derivatives (Toshihiro Ogawa et al., Proceedings of Liquid Crystal Panel Discussion, 2AB03 (1997)), benzophenone derivatives (YK Jang et al., SID Int) Symposium Digest, P-53 (1997).). Among them, cinnamic acid derivatives and coumarin derivatives are preferable, and cinnamic acid derivatives are particularly preferable. Regarding the cinnamic acid derivative, a cinnamic acid derivative having a biphenyl group is preferable, and a cinnamic acid biphenyl derivative and a phenyl cinnamic acid phenyl derivative are particularly preferable.

  The cinnamic acid derivative used as the photoreactive compound in the present invention is preferably a derivative represented by the following general formula C-1.

In the above formula, Ar ¹ and Ar ² each represent an aromatic ring having 6 to 10 carbon atoms or a heterocyclic ring having 5 to 10 carbon atoms, which may have a substituent. Each of Ar ¹ and Ar ² is preferably a substituted or unsubstituted benzene ring, naphthalene ring, furan ring or thiophene ring, and particularly preferably a substituted or unsubstituted benzene ring. X and Y each represent a single bond or a divalent linking group. X and Y are each preferably a single bond or a divalent linking group selected from the group consisting of C = C, C≡C, COO, OCO, CONH, NHCO, OCOO, OCONH and NHCOO, It is more preferable that R ¹ and R ² are substituents for Ar ¹ and Ar ² , respectively. R ¹ and R ² are each preferably an alkyl group, an alkoxyl group, an alkoxycarbonyl group, an alkoxycarbonyloxy group, an alkanoyl group, an alkanoyloxy group, a cyano group, a nitro group or a halogen group. Particularly preferred are a group, an alkoxycarbonyloxy group, an alkanoyloxy group, a cyano group and the like. R ¹ and R ² preferably have a polymerizable group. Examples of preferred polymerizable groups include acryloyloxy group, methacryloyloxy group, vinyl group, vinyloxy group, glycidyl group and oxetane group. Furthermore, each of R ¹ and R ² may be linked to a polymer main chain to form a side chain polymer. R ³ and R ⁴ each represent a substituent on the benzene ring, and examples thereof include an alkyl group having 1 to 6 carbon atoms, an alkoxyl group having 1 to 6 carbon atoms, and a halogen group. n and m independently represent an integer of 0 to 3. Preferably, it is 0 or 1, and it is particularly preferable that at least one of n and m is 1. o and p independently represent an integer of 0 to 4. o and p are each preferably 0 to 2, particularly preferably o and p are each 0 to 2, and o + p is preferably 1 to 3. Q and r each represents an integer of 0 to 4, and preferably 0 or 1.

  The coumarin derivative used as the photoreactive compound in the present invention is preferably a derivative represented by the following general formula C-2.

In the general formula C-2, Ar ¹ , R ¹ , R ² , X, n, p, and q are as defined above in the general formula C-1.

  In the photoreactive compound, a compound that undergoes a photodegradation reaction is described in photodegradable polyimide (Proceedings of the 22nd Liquid Crystal Discussion Symposium, page 1672 A17 (1996)), and can be used in the present invention.

  The compound that causes a photodecomposition reaction used as a photoreactive compound in the present invention may be a dye, that is, a compound having absorption in the visible light region of 400 to 800 nm. Among them, a dichroic dye having a different degree of absorption between the major axis direction and the minor axis direction of the molecule is preferable. The dichroic dye that causes a photodegradation reaction is particularly preferably used for preparing the polarizing film of the present invention. As a dichroic dye that causes a photodecomposition reaction that can be used as a photoreactive compound in the present invention, for example, a tolan derivative represented by the following general formula C-3 can be mentioned as a preferred example.

In the formula, each of R ¹¹ and R ¹² represents a hydrogen atom or an alkyl group, and the alkyl group may have a substituent. R ¹⁴ and R ¹⁵ each represent a hydrogen atom, a lower (C ₁ -C ₆ ) alkyl group or a lower (C ₁ -C ₆ ) alkoxy group. E represents an ethylene group having a plurality of electron-withdrawing groups.

In General Formula C-3, R ¹¹ and R ¹² are each preferably a C 1-20 substitutable alkyl group, and more preferably a C 1-10 substitutable alkyl group. When it has a substituent, the substituent is preferably a polymerizable group. In this specification, “polymerizable group” refers to a functional group used in the polymerization method described in chapters 2 to 5 of “Polymer Chemistry” edited by Shunsuke Murahashi (published by Kyoritsu Shuppan 1966), for example, The atom may be a carbon atom or a non-carbon atom), a hetero-membered ring such as oxirane or aziridine, and a combination of different functional groups such as isocyanate and an amine added thereto. R. A. M.M. Hikmet et al. [Macromolecules, 25, 4194 (1992)] and [Polymer, 34, 8, 1763 (1993)], D.C. J. et al. As described in the research report of Broer et al. (Macromolecules, Vol. 26, p. 1244 (1993)), preferred examples include double bonds, ie, acryloyloxy group, methacryloyloxy group, vinyloxy group and epoxy group. An acryloyloxy group is particularly preferred.

In the general formula C-3, each of R ¹⁴ and R ¹⁵ is preferably a hydrogen atom, a methyl group, or a methoxy group.
In the general formula C-3, the plurality of electron withdrawing groups that E has may be the same as or different from each other. Preferred examples of the electron withdrawing group include a cyano group and an alkoxyoxycarbonyl group (more preferably, an alkoxyoxycarbonyl group having an alkyl moiety having 2 to 12 carbon atoms).

  When the photoreactive compound is a multimer such as a monopolymer or a copolymer, the weight average molecular weight is not particularly limited, but is preferably 1,000 to 500,000, more preferably 5 000 to 300,000, and more preferably 7,000 to 100,000. Further, when the photoreactive compound is a copolymer containing a repeating unit derived from a photoreactive compound and a repeating unit derived from another monomer, the copolymer molar ratio is not particularly limited, The molar ratio of the repeating unit derived from the photoreactive compound is preferably 0.1 to 99.9, more preferably 1 to 99, when the total molar ratio of all monomers is 100. More preferably, it is -90.

  Below, the specific example of the photoreactive compound which can be used for this invention is given. However, the scope of the present invention is not limited to these. In the following specific examples, l, m, and n for the copolymer indicate the polymerization molar ratio of each monomer, and n for the homopolymer indicates the average degree of polymerization.

  Moreover, what is marketed as a photoreactive compound can also be used for this invention. For example, azobenzene (manufactured by Aldrich), 4-nitroazobenzene (manufactured by Aldrich), disperse thread 1 (manufactured by Aldrich), disperse orange 3 (manufactured by Aldrich), Sudan 1 (manufactured by Aldrich), etc. it can.

  In addition, commercially available dichroic dyes such as G-202, G-205, G-206, G-207, G-232, G-239, G-241, G-254, G-256, G-289, etc. (Both manufactured by Nippon Photosensitive Dye Co., Ltd.) can be used.

[Non-liquid crystalline polymer]
The non-liquid crystalline polymer that can be used in the present invention is not particularly limited, but a polymer generally used as a film support is preferable. Specifically, a polyacrylate polymer (for example, polymethyl acrylate), a polymethacrylate polymer (for example, polymethyl methacrylate), a polyvinyl alcohol polymer (for example, trade name POVAL (manufactured by Kuraray)), a polycarbonate-based polymer Molecule, polysulfone-based polymer, cellulose-based polymer (for example, triacetylcellulose (trade name Fuji Fujitac (manufactured by Fuji Photo Film))), polyolefin-based polymer (for example, trade name ZEONEX (manufactured by ZEON Corporation), ARTON (Japan) Synthetic rubber)) or copolymers of these polymers are preferred examples. Among these, polyacrylate polymers, polymethacrylate polymers, and cellulose polymers are particularly preferable. The non-liquid crystalline polymer may be stretched uniaxially or biaxially.

The preferred range of the content of the photoreactive compound is determined depending on the use, etc., but in general, it is preferably 1 to 50 parts by mass with respect to the content of the non-liquid crystalline polymer. -30 mass parts is more preferable. For example, when the polymer film is produced by the solvent cast method as described below, the dope is prepared so that the contents of the photoreactive compound and the non-liquid crystalline compound are in the above range. Is preferred.
The polymer film is made of a material other than the photoreactive compound and the non-liquid crystalline polymer, for example, a polymerization initiator, a photosensitizer, a plasticizer, and a stabilizer, as long as the expression of optical anisotropy is not inhibited. And may contain a non-combustible agent.

Next, the manufacturing method of the optically anisotropic polymer film of the present invention will be described in detail.
[Preparation of optically anisotropic polymer film]
First, a polymer film containing at least one photoreactive compound and at least one non-liquid crystalline polymer is prepared. For film formation of the polymer film, both melt film formation and solution film formation can be employed, but solution film formation is preferred. For example, the photoreactive compound and the non-liquid crystalline polymer can be dissolved in a solvent and used as a dope, and can be produced by a solvent cast method. A general solvent casting method is described in each specification of US Pat. No. 2,336,310, Japanese Patent Publication No. 45-4554, and the like. The dope is cast on a drum or band and the solvent is evaporated to form a film. The concentration of the dope before casting is preferably adjusted so that the solid content is 10 to 40% by weight. The solid content is more preferably 18 to 35% by weight. Two or more dopes can be cast. The surface of the drum or band is preferably finished in a mirror state. The obtained film is peeled off from the drum or band to produce a polymer film. The solvent used for dope preparation is preferably a solvent that dissolves both the photoreactive compound and the non-liquid crystalline polymer. In addition, you may perform the said peeling process after the light irradiation process which is a next process as needed.

  Alternatively, a polymer film can be prepared by forming a frame using a spacer on an appropriate support, pouring the dope into the frame, and drying the solvent. As the support, a glass substrate, a Teflon plate (Teflon: registered trademark), various polymers, or the like can be used. Furthermore, you may produce a polymer film by the method of drying, after apply | coating the said dope on a suitable support body. As the coating method, known methods such as curtain coating method, extrusion coating method, roll coating method, spin coating method, dip coating method, bar coating method, spray coating method, slide coating method, print coating method, etc. are employed. . And a polymer film can be produced by peeling off the film obtained above from a support.

  The stripping step may be performed after the light irradiation step, which is the next step, if necessary. The optical element or the optical film is integrated with the support without performing the stripping step after the light irradiation step. Etc. may be used. In the case of using it integrally with the support without performing the stripping step, the support is preferably a glass substrate or a polymer film having a light transmittance of 80% or more. When using a polymer film as a support, the thickness is preferably 10 to 500 μm, more preferably 20 to 200 μm, and most preferably 35 to 110 μm.

[Stretching]
The polymer film obtained above may be stretched uniaxially or biaxially under stress as necessary. For the stretching, a heat stretching method, a humidity stretching method, a heat stretching method under humidity control, or the like can be used, but a heat stretching method or a heat stretching method under humidity conditioning is preferable. Further, tenter stretching is preferably used, and 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, the separation timing, etc. as small as possible. The draw ratio is preferably 1.01 to 10, and more preferably 1.03 to 3.

[Light irradiation]
Optical anisotropy in which optical anisotropy is controlled by applying light irradiation to the polymer film obtained above or on a polymer film formed on a support to develop refractive index anisotropy of the polymer film A polymer film is produced. Light irradiation may be performed while stretching the polymer film as necessary.

  The light irradiation in the present invention is an operation for causing a photoreaction in the photoreactive compound. The wavelength of light used varies depending on the photoreactive compound used, and is not particularly limited as long as it is a wavelength necessary for the photoreaction. Preferably, the peak wavelength of light used for light irradiation is 200 nm to 700 nm, more preferably ultraviolet light having a peak wavelength of light of 400 nm or less.

  The light source used for light irradiation is a commonly used light source such as a tungsten lamp, a halogen lamp, a xenon lamp, a xenon flash lamp, a mercury lamp, a mercury xenon lamp, a carbon arc lamp, or various lasers (eg, semiconductor laser, helium). Neon laser, argon ion laser, helium cadmium laser, YAG laser), light emitting diode, cathode ray tube, and the like.

  The light irradiation may be non-polarized light or polarized light, but it is preferable to use polarized light, more preferably linearly polarized light. As means for obtaining linearly polarized light, a method using a polarizing plate (eg, an iodine polarizing plate, a dichroic dye polarizing plate, a wire grid polarizing plate), a reflection using a prism element (eg, Glan-Thompson prism) or Brewster angle A method using a type polarizer or a method using light emitted from a laser light source having polarization can be employed. Moreover, you may selectively irradiate only the light of the required wavelength using a filter, a wavelength conversion element, etc.

  The light to irradiate employs a method of irradiating the polymer film with light from the top surface or the back surface perpendicular to the polymer film or obliquely. The incident angle of the light varies depending on the type of the photoreactive substance, and is, for example, 0 to 80 °, preferably 40 to 80 °, more preferably 50 to 70 ° with respect to the surface of the polymer film.

  When patterning of the optically anisotropic polymer film is necessary, a method of performing light irradiation using a photomask as many times as necessary for pattern formation or a method of writing a pattern by laser beam scanning can be employed.

The optically anisotropic polymer film of the present invention can be used for various applications. For example, it can be used as an optical compensation film that contributes to improving the viewing angle characteristics of a liquid crystal display device.
[Optical compensation film]
The optically anisotropic polymer film of the present invention can be used alone as an optical compensation film in various image devices as it is. Depending on the stretch ratio of the polymer film and the amount of light irradiation, the range of optical characteristics required for the optical compensation film can be obtained.

  The optically anisotropic polymer film of the present invention can be used alone or as an optical compensation film, but may have other layers as desired. For example, an optically anisotropic layer formed from a liquid crystal composition containing at least one liquid crystal compound may be provided on the optically anisotropic film. The thickness of the optically anisotropic layer is preferably 0.1 to 20 μm, and more preferably 0.5 to 10 μm.

  For the formation of the optically anisotropic layer, either a rod-like liquid crystal compound or a disk-like liquid crystal compound can be used. 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 disk-like liquid crystal compound having a reactive group because temperature change and humidity change can be reduced. In the case of a mixture, at least one kind is a reactive group in one molecule. More preferably, it is a liquid crystalline compound having 2 or more. The liquid crystalline compound may be a mixture of two or more, and in that case, at least one of them preferably has two or more reactive groups. The liquid crystal composition may contain an alignment controller, a polymerization initiator, a sensitizer, a crosslinking agent, and the like in addition to at least one liquid crystal compound.

  Further, an alignment layer for aligning liquid crystal is provided between the polymer film having optical anisotropy and the optical anisotropic layer formed from the polymer of the liquid crystal composition. Also good. When the alignment layer is provided, a general horizontal or vertical alignment film can be used for the alignment layer. As a particularly preferred example, there can be mentioned a method of subjecting an alignment film such as polyvinyl alcohol or polyimide to normal rubbing.

  Various known polymerization methods using heat or electromagnetic waves can be employed for forming the polymer of the liquid crystal composition, but radical polymerization using a photopolymerization initiator using ultraviolet light is particularly preferable. In the case where the polymerizable group is an epoxy group, a method of thermally cross-linking by adding a diamine is also a preferred example.

The optically anisotropic polymer film of the present invention may be integrated with a polarizing film and incorporated in an image display device as a member of a polarizing plate.
[Polarizer]
One aspect of the polarizing plate of the present invention includes a polarizing film and a pair of protective films sandwiching the polarizing film, and at least one of the pair of protective films is the optically anisotropic polymer film of the present invention. . 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 directions thereof coincide. 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 optically anisotropic polymer film of the present invention is determined by the thickness, free volume, hydrophilicity / hydrophobicity, etc. of the polymer film (and the optically anisotropic layer made of a polymer of a liquid crystalline 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, one of the protective films for the polarizing film is the optically anisotropic polymer film of the present invention for the purpose of reducing the thickness. When the optically anisotropic polymer film further has the optically anisotropic layer, the surface of the polarizing film and the back surface of the optically anisotropic polymer film (the surface on the side where the optically anisotropic layer is not formed) ). The optically anisotropic polymer film and the polarizing film of the present invention are preferably subjected to a fixing treatment from the viewpoints 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.

  The optically anisotropic polymer film of the present invention and the polarizing plate having the film are suitable for use in an image display device, particularly a liquid crystal display device having a liquid crystal cell. Use in an image display device, particularly a liquid crystal display device, contributes to improvement in display characteristics such as viewing angle characteristics.

Next, the manufacturing method of the polarizing film of this invention is demonstrated in detail.
[Polarized film]
The present invention is obtained by irradiating a polymer film containing at least one photoreactive compound having absorption in a wavelength range of 400 nm to 800 nm and at least one non-liquid crystalline polymer with polarized light, and exhibiting polarization property by polarized light irradiation. The present invention relates to a polarizing film. The maximum absorption of the photoreactive compound does not have to be in the wavelength range of 400 nm to 800 nm, and the photoreactive compound only needs to have absorption in the wavelength range of 400 nm to 800 nm. When the polymer film is irradiated with linearly polarized light, the photoreactive compound undergoes a photoreaction, thereby exhibiting polarization. As a result, the polarizability of the polymer can be arbitrarily controlled.

  Hereinafter, various materials used for producing the polarizing film of the present invention will be described in detail.

  Regarding the photoreactive compound used for the polarizing film, a photoreactive compound having absorption in a wavelength region of 400 nm to 800 nm in the above-described photoreactive compound is used. Specifically, azobenzene compounds and tolan compounds are preferably used. Further, for example, azobenzene (manufactured by Aldrich), 4-nitroazobenzene (manufactured by Aldrich), Disperse Red 1 (manufactured by Aldrich), Disperse Orange 3 (manufactured by Aldrich), Sudan 1 (manufactured by Aldrich), etc. Compounds such as G-202, G-205, G-206, G-207, G-232, G-239, G-241, G-254, G-256, G-289, etc. Commercially available dichroic dyes such as those manufactured by the same company can be used.

  The non-liquid crystalline polymer used for producing the polarizing film is the same as described above.

Next, the manufacturing method of the polarizing film of this invention is demonstrated in detail.
[Preparation of polarizing film]
First, a polymer film containing at least one photoreactive compound having absorption in a wavelength range of 400 nm to 800 nm and at least one non-liquid crystalline polymer is prepared. Regarding the film formation of the polymer film, the above description can be adopted.

[Linear polarized light irradiation]
An optically anisotropic polymer film having a controlled polarization property is obtained by irradiating the polymer film obtained above or a polymer film formed on a support with linearly polarized light to develop the polarization property of the polymer film. To manufacture.

The linearly polarized light irradiation in the present invention is an operation for causing a photoreaction in the photoreactive compound. The wavelength of light used varies depending on the photoreactive compound used, and is not particularly limited as long as it is a wavelength necessary for the photoreaction. Preferably, the peak wavelength of light used for light irradiation is 200 nm to 700 nm, more preferably ultraviolet light having a peak wavelength of light of 400 nm or less. The above-mentioned explanation can be adopted as a light source used for polarized light irradiation and means for obtaining linearly polarized light.
For the straight line to be irradiated, a method of irradiating polarized light from the top surface or the back surface of the polymer film perpendicular to the polymer film or obliquely is adopted, and a method of irradiating polarized light from the perpendicular is preferable.

  When patterning of a polarizing film is necessary, a method of applying polarized light irradiation using a photomask as many times as necessary for pattern creation or a method of writing a pattern by laser beam scanning can be employed.

  The polarizing film of the present invention can be used for various applications. For example, the polarizing film of the present invention can be used alone as a polarizing film in various image devices as it is. Furthermore, the polarizing film of the present invention can also be used as a color filter having polarizing properties.

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.
[Example 1]
The following dope solution 1 was prepared, filtered through a microfilter (DISMIC-13 PTFE 0.45 mm: manufactured by ADVANTEC), and poured into a 3 cm × 3 cm square frame made of 180 μm thick Teflon tape on a glass substrate. . The solvent was evaporated at room temperature for about 12 hours to produce a polymer film having a thickness of 33 μm.
Next, the light emitted from the halogen lamp is converted into linearly polarized light through the polarizing plate, and irradiated to the polymer film prepared above at an intensity of 100 mW / cm ² (365 nm) for 60 minutes. A polymer film with controlled optical anisotropy was obtained on a glass substrate. The retardation value (Re value) of the obtained polymer film was measured by the Senarmon method together with the glass substrate, and a value of Re (650 nm) = 78 nm was obtained.

Dope solution 1
Polymethylmethacrylate (Aldrich) 100mg
Disperse Thread 1 (Aldrich) 10mg
Chloroform 1mL

[Example 2]
A polymer film with controlled optical anisotropy was produced on a glass substrate in the same manner as in Example 1 except that the irradiation time of linearly polarized light was changed with respect to Example 1. The retardation value (Re value) of each polymer film obtained was measured using KOBRA 31PRN (manufactured by Oji Scientific Instruments) together with the glass substrate, and the direction perpendicular to the direction of the irradiated linearly polarized light was measured. The expression of retardation with a slow axis was confirmed. The dependency of retardation on irradiation time is shown below. As a result, it became clear that the front retardation value could be controlled by controlling the irradiation time.

Irradiation time Re (629nm)
3 minutes 16.3
5 minutes 32.5
10 minutes 37.9
20 minutes 59.6
30 minutes 65.0

[Example 3]
In the same manner as in Example 1, a polymer film having a film thickness of 33 μm was produced. Next, the light emitted from the halogen lamp is converted into linearly polarized light through the polarizing plate, and irradiated to the polymer film prepared above at an intensity of 100 mW / cm ² (365 nm) for 30 minutes from a direction of 45 degrees. Thus, a polymer film with controlled optical anisotropy was obtained. Using the KOBRA WR (manufactured by Oji Scientific Instruments Co., Ltd.) for the obtained polymer film, the in-plane slow axis (determined by KOBRA WR) is the tilt axis (rotation axis) and the film normal direction The retardation value (Re value) measured by making light having a wavelength of 629 nm incident from the direction inclined at each angle from −45 ° to + 45 ° at intervals of 15 ° was measured, and the angle dependency was examined. . The results are shown below. From the result, it became clear that the retardation can be controlled three-dimensionally.

Incident angle Re (629nm)
-45 ° 18.9
-30 ° 18.6
-15 ° 18.2
-0 ° 15.6
-15 ° 13.0
-30 ° 10.4
-45 ° 9.7

[Example 4]
The following dope solution 4 was prepared, filtered through a microfilter (DISMIC-13 PTFE 0.45 mm: manufactured by ADVANTEC), and poured into a 3 cm × 3 cm square frame made of 180 μm thick Teflon tape on a glass substrate. . The solvent was evaporated at room temperature for about 12 hours to produce a polymer film with a thickness of 30 μm.
Next, the light emitted from the halogen lamp was converted into linearly polarized light through the polarizing plate, and irradiated for 60 minutes at an intensity of 100 mW / cm ² (365 nm) from the perpendicular direction to the polymer film produced above. . Thereafter, the film was peeled from the glass substrate to obtain a polymer film with controlled optical anisotropy.
The retardation value (Re value) of the obtained polymer film was measured using KOBRA 31PRN (manufactured by Oji Scientific Instruments), and the direction perpendicular to the direction of the irradiated linearly polarized light was used as the slow axis. A value of Re (650 nm) of 27 nm was obtained.

Dope solution 4
TAC cotton 200mg
Disperse Thread 1 (Aldrich) 20mg
Chloroform 2mL

[Example 5]
The following dope solution 5 was prepared, filtered with a microfilter (DISMIC-13 PTFE 0.45 mm: manufactured by ADVANTEC), and poured into a 3 cm × 3 cm square frame made of 180 μm thick Teflon tape on a glass substrate. . The solvent was evaporated at room temperature for about 12 hours to produce a polymer film with a thickness of 31 μm.
Next, the light emitted from the ultraviolet irradiation device is converted into linearly polarized light through the polarizing plate, and irradiated for 30 minutes at an intensity of 100 mW / cm ² (365 nm) from the perpendicular direction to the polymer film produced above. Thus, a polymer film with controlled optical anisotropy was obtained.
The retardation value (Re value) of the obtained polymer film was measured by making light having a wavelength of 548 nm incident in the normal direction of the film in KOBRA 31PRN (manufactured by Oji Scientific Instruments), and in the direction of the linearly polarized light irradiated. A value of Re (548 nm) of 12 nm was obtained with the direction orthogonal to the slow axis.

Dope solution 5
Polymethylmethacrylate (Aldrich) 100mg
The following liquid crystalline cinnamic acid derivative 5-1 10 mg
Chloroform 2mL

  The liquid crystalline cinnamic acid derivative 5-1 includes 4- (4-acryloyloxy) butyloxy-3-methyl-cinnamic acid synthesized using the method described in Japanese Patent Laid-Open Publication No. 2002-97170, and a public patent. It can synthesize | combine by using 4-hydroxybiphenyl-4'-carboxylic acid 4-acryloyloxybutyl synthesize | combined using the method of Unexamined-Japanese-Patent No. 2003-327561, and condensing using the dicyclohexyl carbodiimide method.

[Example 6]
The following dope solution 6 is prepared, filtered through a microfilter (DISMIC-13 PTFE 0.45 mm: manufactured by ADVANTEC), applied to a glass substrate by spin coating (3500 rpm, 20 s), and a polymer having a film thickness of 5.6 μm. A film was prepared.
Next, the light emitted from the ultraviolet irradiation device is converted into linearly polarized light through the polarizing plate, and irradiated for 15 minutes at an intensity of 100 mW / cm ² (365 nm) from the perpendicular direction to the polymer film produced above. Thus, a polymer film with controlled optical anisotropy was obtained.
The retardation value (Re value) of the obtained polymer film was measured by making light having a wavelength of 548 nm incident in the normal direction of the film in KOBRA 31PRN (manufactured by Oji Scientific Instruments), and in the direction of the linearly polarized light irradiated. A value of Re (548 nm) 7.2 nm was obtained with the direction orthogonal to the slow axis.

Dope solution 6
Polymethylmethacrylate (Aldrich) 100mg
The following liquid crystalline cinnamic acid derivative 6-1 50 mg
Chloroform 2mL

  The liquid crystalline cinnamic acid derivative 6-1 was synthesized from 4- (4-methacryloyloxy) butyloxycinnamic acid and 4-hydroxy-4'- using the method described in JP-A-2002-97170. It can be synthesized by condensing cyanobiphenyl using the dicyclohexylcarbodiimide method to give 4- (4-methacryloyloxy) butyloxycinnamic acid 4′-cyanobiphenyl, and then polymerizing by AIBN method.

[Example 7]
The following dope solution 7 is prepared, filtered through a microfilter (DISMIC-13 PTFE 0.45 mm: manufactured by ADVANTEC), applied to a glass substrate by spin coating (3500 rpm, 20 s), and a polymer having a film thickness of 4.6 μm. A film was prepared.
Next, the light emitted from the ultraviolet irradiation device is converted into linearly polarized light through the polarizing plate, and irradiated for 15 minutes at an intensity of 100 mW / cm ² (365 nm) from the perpendicular direction to the polymer film produced above. Thus, a polymer film with controlled optical anisotropy was obtained.
The retardation value (Re value) of the obtained polymer film was measured by making light having a wavelength of 548 nm incident in the normal direction of the film in KOBRA 31PRN (manufactured by Oji Scientific Instruments), and in the direction of the linearly polarized light irradiated. The value of Re (548 nm) 11.8 nm was obtained with the direction orthogonal to the slow axis.

Dope solution 7
Polymethylmethacrylate (Aldrich) 100mg
The following liquid crystalline cinnamic acid derivative 7-1 100 mg
Tetrahydrofuran 2mL

[Example 8]
The following dope solution 8 is prepared, filtered through a microfilter (DISMIC-13 PTFE 0.45 mm: manufactured by ADVANTEC), applied to a glass substrate by spin coating (3500 rpm, 20 s), and a polymer having a film thickness of 5.2 μm. A film was prepared.
Next, the light emitted from the ultraviolet irradiation device is converted into linearly polarized light through the polarizing plate, and irradiated for 15 minutes at an intensity of 100 mW / cm ² (365 nm) from the perpendicular direction to the polymer film produced above. Thus, a polymer film with controlled optical anisotropy was obtained.
The retardation value (Re value) of the obtained polymer film was measured by making light having a wavelength of 548 nm incident in the normal direction of the film in KOBRA 31PRN (manufactured by Oji Scientific Instruments), and in the direction of the linearly polarized light irradiated. A value of Re (548 nm) 8.0 nm was obtained with the direction orthogonal to the slow axis.

Dope solution 8
Polymethylmethacrylate (Aldrich) 100mg
The following liquid crystalline cinnamic acid derivative 8-1 50 mg
Tetrahydrofuran 2mL

[Example 9]
The dope solution prepared in the same manner as in Example 4 was poured into a 6 cm × 3 cm square frame made of 180 μm thick Teflon tape on a glass substrate. The solvent was evaporated at room temperature for about 12 hours to produce a polymer film having a thickness of 32 μm. The obtained polymer film was peeled off, and uniaxially stretched 1.1 times at 60% humidity and 60 ° C. using a stretching machine (manufactured by Ono Control & Measurement Co., Ltd.).
Next, the light emitted from the halogen lamp is converted into linearly polarized light through the polarizing plate, and the polarized light orthogonal to the stretching direction of the polymer film is converted to 100 mW / from the direction perpendicular to the polymer film produced above. A polymer film with controlled optical anisotropy was obtained by irradiation for 60 minutes at an intensity of cm ² (365 nm). The retardation value (Re value) of the obtained polymer film was measured using KOBRA 31PRN (manufactured by Oji Scientific Instruments), and the direction perpendicular to the direction of the irradiated linearly polarized light was used as the slow axis. Measurement was performed, and a value of Re (650 nm) 29 nm was obtained with the slow axis as the direction parallel to the stretching direction of the polymer film.

[Example 10]
The dope solution prepared in the same manner as in Example 4 was poured into a 6 cm × 3 cm square frame made of 180 μm thick Teflon tape on a glass substrate. The solvent was evaporated at room temperature for about 12 hours to produce a polymer film having a thickness of 32 μm. The obtained polymer film was peeled off, and uniaxially stretched 1.1 times at 60% humidity and 60 ° C. using a stretching machine (manufactured by Ono Control & Measurement Co., Ltd.).
Next, the light emitted from the halogen lamp is converted into linearly polarized light through a polarizing plate, and polarized light parallel to the stretching direction of the polymer film is converted to 100 mW / from a direction perpendicular to the polymer film produced above. A polymer film with controlled optical anisotropy was obtained by irradiation for 60 minutes at an intensity of cm ² (365 nm). The retardation value (Re value) of the obtained polymer film was obtained using the KOBRA 31PRN (manufactured by Oji Scientific Instruments) and irradiated. A direction perpendicular to the direction of linearly polarized light was measured as the slow axis, and a value of Re (650 nm) 26 nm was obtained with the direction perpendicular to the stretching direction of the polymer film as the slow axis.

[Example 11]
On the polymer film prepared in Example 7, the following alignment layer coating solution AL-11 was applied with a # 14 wire bar coater, dried, and rubbed in parallel with the direction of the irradiated linearly polarized light. . Next, the following liquid crystal optically anisotropic layer coating liquid LC-11 is applied by spin coating (2000 rpm, 20 s) and cured by ultraviolet irradiation (254 nm, 50 mW / cm ² , 15 seconds). A 2 μm optically anisotropic layer was formed.

Coating liquid AL-11 for alignment layer
───────────────────────────────────
Coating liquid composition for alignment layer (%)
───────────────────────────────────
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
───────────────────────────────────

変性ポリビニルアルコールは特開平９−１５２５０９号公報のものを用いた。

As the modified polyvinyl alcohol, one disclosed in JP-A-9-152509 was used.

Liquid crystal optical anisotropic layer coating liquid LC-11
───────────────────────────────────
Coating liquid composition for liquid crystal optical anisotropic layer (%)
───────────────────────────────────
Liquid crystalline compound LC-11-1 20.0
Ethylene oxide modified trimethylolpropane 0.1
Triacrylate (Osaka Organic Chemical Co., Ltd.)
Irgacure 907 (0.3 wt%) 0.03
(Ciba Specialty Chemicals)
Kayacure DETX-S 0.01
(Nippon Kayaku Co., Ltd.)
Methyl ethyl ketone 79.86
───────────────────────────────────

  Liquid crystalline compound LC-11-1 can be found in Fuji Photo Film Research Report, Vol. 42, p. 48 (1997), or “Next Generation Polymers and Supramolecules Controlling Light”, edited by the Society of Polymer Science (2000). ) And synthesized by the method described.

[Example 12]
In Example 11, an optical film having a thickness of 2.2 μm was formed on the polymer film produced in Example 7 in the same manner as in Example 11 except that rubbing was performed perpendicularly to the direction of the irradiated linearly polarized light. An isotropic layer was formed.

[Example 13]
"Wavelength dependence of front retardation"
The retardation values (Re values) of the polymer films obtained in Examples 11 and 12 were measured using KOBRA 31PRN (manufactured by Oji Scientific Instruments). The results are shown below.
Re (499nm) Re (548nm) Re (623nm) Re (749nm)
Example 11: 22.2 19.5 18.0 16.5
Example 12: 43.1 38.9 36.9 34.8

  Furthermore, the graph which shows the wavelength dependence of retardation was created about the said result. As shown in FIG. In the graph, the retardation value at each wavelength was normalized and plotted based on the retardation of 548 nm. From the graph of FIG. 1, it is clear that the wavelength dependency of the front retardation can be easily controlled by this method.

[Example 14: Preparation of patterned optically anisotropic polymer film 1]
The following dope solution 14 is prepared, filtered through a microfilter (DISMIC-13 PTFE 0.45 mm: manufactured by ADVANTEC), applied to a glass substrate by spin coating (3500 rpm, 20 s), and a polymer having a film thickness of 2.6 μm. A film was prepared.
Next, the light emitted from the ultraviolet irradiation device is converted into linearly polarized light through a polarizing plate, and is 100 mW / cm ² (365 nm) through a photomask from a direction perpendicular to the polymer film produced above. A polymer film with controlled optical anisotropy was obtained by irradiation with intensity for 15 minutes.
The obtained polymer film was observed with a polarizing microscope, and it was confirmed that a pattern was formed. FIG. 2 shows the observation results of the diagonal position and FIG. 3 shows the extinction position.

Dope solution 14
200 mg of the following azobenzene derivative 14-1
Chloroform 1mL

[Example 15: Preparation of patterned optically anisotropic polymer film 2]
The following dope solution 15 is prepared, filtered through a microfilter (DISMIC-13 PTFE 0.45 mm: manufactured by ADVANTEC), applied to a glass substrate by spin coating (3500 rpm, 20 s), and a polymer film having a thickness of 2 μm is formed. Produced.
Next, the light emitted from the ultraviolet irradiation device is converted into linearly polarized light through a polarizing plate, and 100 mW / cm ² (365 nm) through a photomask from a direction perpendicular to the polymer film produced above. A polymer film with controlled optical anisotropy was obtained by irradiation for 15 minutes at an intensity of.

Dope solution 15
Polymethylmethacrylate (Aldrich) 100mg
Two-color dye G-254 (Nippon Senshoku Dye) 10mg
Chloroform 1mL

[Example 16: Production of polarizing film 1]
The polymer film produced in the same manner as in Example 1 was converted from ultraviolet light emitted from a UV irradiator (manufactured by HOYA-SCOTT, UL-250) into linearly polarized light via a polarizing plate, Irradiation was performed for 900 seconds at an intensity of 100 mW (365 nm) from a direction perpendicular to the film surface to obtain a polarizing film on a glass substrate.
The polarization transmission spectrum of the obtained polarizing film was measured by inserting a polarizing plate into the optical path of a spectrophotometer (UV-2400PC, manufactured by Simadzu), and the transmitted light had a dichroic ratio = 2.7 (580 nm). It was confirmed to have polarization.

[Example 17: Production of polarizing film 2]
The following dope solution 17 is prepared, filtered through a microfilter (DISMIC-13 PTFE 0.45 mm: manufactured by ADVANTEC), applied to a glass substrate by spin coating (3500 rpm, 20 s), and a polymer film having a thickness of 2 μm is formed. Produced. The tolan derivative 17-1 used as a photoreactive compound is a dye having an absorption maximum at a wavelength of 469 nm (in chloroform).
Ultraviolet light emitted from a UV irradiator (manufactured by HOYA-SCOTT, UL-250) is converted into linearly polarized light through a polarizing plate, and the polymer film thus prepared is applied to the film surface. On the other hand, irradiation was carried out for 900 seconds at an intensity of 100 mW (365 nm) from a perpendicular direction to obtain a polarizing film on a glass substrate.
The polarization transmission spectrum of the obtained polarizing film was measured by inserting a polarizing plate into the optical path of a spectrophotometer (UV-2400PC, manufactured by Simadzu), and the transmitted light has a dichroic ratio = 34 (440 nm). Confirmed to have.

Dope solution 17
Polymethylmethacrylate (Aldrich) 100mg
The following Tran derivative 17-1 10mg
Chloroform 1mL

[Example 18: Production of polarizing film 3]
The following dope solution 18 is prepared, filtered through a microfilter (DISMIC-13 PTFE 0.45 mm: manufactured by ADVANTEC), applied to a glass substrate by spin coating (3500 rpm, 20 s), and a polymer film having a thickness of 2 μm is formed. Produced.
Ultraviolet light emitted from a UV irradiator (manufactured by HOYA-SCOTT, UL-250) is converted into linearly polarized light through a polarizing plate, and the polymer film thus prepared is applied to the film surface. On the other hand, irradiation was carried out for 900 seconds at an intensity of 100 mW (365 nm) from a perpendicular direction to obtain a polarizing film on a glass substrate.
The polarization transmission spectrum of the obtained polarizing film was measured by inserting a polarizing plate into the optical path of a spectrophotometer (UV-2400PC, manufactured by Simadzu), and the transmitted light was polarized light having a dichroic ratio = 1.5 (440 nm). It was confirmed that it has sex.

Dope solution 18
Polymethylmethacrylate (Aldrich) 100mg
Two-color dye G-206 (Nippon Senshoku Dye) 9mg
Two-color dye G-254 (Nippon Senshoku Dye) 3mg
Chloroform 1mL

[Example 19: Production of polarizing film 4]
The following dope solution 19 is prepared, filtered through a microfilter (DISMIC-13 PTFE 0.45 mm: manufactured by ADVANTEC), applied to a glass substrate by spin coating (3500 rpm, 20 s), and a polymer film having a thickness of 2 μm is formed. Produced. The azobenzene derivative 19-1 used as the photoreactive compound was a compound having a maximum absorption at a wavelength of 360 nm (in chloroform).
Ultraviolet light emitted from a UV irradiator (manufactured by HOYA-SCOTT, UL-250) is converted into linearly polarized light through a polarizing plate, and the polymer film thus prepared is applied to the film surface. On the other hand, irradiation was carried out for 900 seconds at an intensity of 100 mW (365 nm) from a perpendicular direction to obtain a polarizing film on a glass substrate.
The polarization transmission spectrum of the obtained polarizing film was measured by inserting a polarizing plate into the optical path of a spectrophotometer (UV-2400PC, manufactured by Simadzu), and the polarization property of the transmission dichroic ratio = 3.5 (440 nm) was measured. Confirmed to have.

Dope solution 19
Polymethylmethacrylate (Aldrich) 100mg
10 mg of the following azobenzene derivative 19-1
Chloroform 1mL

According to the present invention, the retardation of the polymer film can be arbitrarily controlled, and the wavelength dispersibility can also be controlled. Therefore, according to the present invention, it is possible to provide an optically anisotropic polymer film that exhibits optical anisotropy optimum for optical compensation of liquid crystal display devices of various modes, that is, useful as an optical compensation film. Furthermore, it can be used as a protective film for polarizing plates and various polymer films used in various image display devices, particularly liquid crystal display devices.
In addition, according to the present invention, it is possible to provide a polarizing film on which a fine polarizing pattern is formed and a color filter having polarizing properties.

It is a graph which shows the wavelength dependence of the retardation of the optically anisotropic polymer film of Example 11 and 12. It is a figure which shows the polarizing microscope observation result of the diagonal position of the optically anisotropic polymer film of Example 14. It is a figure which shows the polarizing microscope observation result of the quenching position of the optically anisotropic polymer film of Example 14.

Claims (21)

An optically anisotropic polymer film obtained by irradiating a polymer film containing at least one photoreactive compound and at least one non-liquid crystalline polymer with light and expressing or changing optical anisotropy by light irradiation. The optically anisotropic polymer film according to claim 1, wherein the photoreactive compound is a photoreactive compound having a polymerizable group. The optically anisotropic polymer film according to claim 1, wherein the photoreactive compound is a photoreactive compound having liquid crystallinity. The optically anisotropic polymer film according to any one of claims 1 to 3, wherein the photoreactive compound is a cinnamic acid derivative or a coumarin derivative. The non-liquid crystalline polymer is a polyacrylate polymer, polymethacrylate polymer, polyvinyl alcohol polymer, polycarbonate polymer, polysulfone polymer, cellulose polymer, polyolefin polymer, or a polymer thereof. The optically anisotropic polymer film according to claim 1, wherein the optically anisotropic polymer film is a copolymer. The optically anisotropic polymer film according to claim 1, wherein the polymer film is a polymer film stretched uniaxially or biaxially. Furthermore, the optically anisotropic polymer film of any one of Claims 1-6 which has an optically anisotropic layer containing the polymer of the liquid-crystal composition containing an at least 1 type of liquid crystal compound. The optically anisotropic polymer film according to claim 1, which is used as an optical compensation film. The polarizing plate which has a polarizing film and the optically anisotropic polymer film of any one of Claims 1-7 at least. The image display element which has the optically anisotropic polymer film of any one of Claims 1-7, or the polarizing plate of Claim 9. An optical anisotropy comprising a light irradiation step of irradiating a polymer film containing at least one photoreactive compound and at least one non-liquid crystalline polymer to control the optical anisotropy of the polymer film For producing a conductive polymer film. The method according to claim 11, further comprising a stretching step of subjecting the polymer film to uniaxial or biaxial stretching before the light irradiation step. The method according to claim 11 or 12, wherein, in the light irradiation step, light is irradiated from a direction inclined by θ ° (0 <θ) from a normal direction of the polymer film. The method according to claim 11, wherein in the light irradiation step, light to be irradiated is linearly polarized light. The method according to any one of claims 11 to 14, wherein in the light irradiation step, light to be irradiated is ultraviolet light. Polarizing film obtained by irradiating a polymer film containing at least one photoreactive compound having absorption in a wavelength region of 400 nm to 800 nm and at least one non-liquid crystalline polymer with polarized light, and exhibiting polarization property by polarized light irradiation . The polarizing film according to claim 16, wherein the photoreactive compound is a dichroic photoreactive compound. The polarizing film according to claim 16, wherein the photoreactive compound is a photodegradable compound. Production of a polarizing film comprising a light irradiation step of irradiating a linearly polarized light to a polymer film containing at least one photoreactive compound and at least one non-liquid crystalline polymer to control the polarization property of the polymer film Method. A color filter comprising the polarizing film according to claim 16. The image display element which has a polarizing film of any one of Claims 16-18, or a color filter of Claim 20.

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