JP2008065134A - Polarizer, polarizing plate, optical member and liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polarizer that achieves thinning, and at the same time satisfies high degree of polarization, high durability and good handleability, to provide a polarizing plate where the polarizer is formed and an optical member with the use of the polarizer, and to provide a liquid crystal display device comprising the optical member. <P>SOLUTION: The polarizer includes a complex consisting of a molecule tube and a conjugate macromolecule having absorption in a visible light region included in the molecule tube, and the complex is oriented substantially in one direction. Preferably, an optical absorption peak wavelength of the complex is within a range of 380-780 nm. Also, it is preferable that the conjugate macromolecule consists of polyaniline, and the molecule tube consists of intermolecular crosslinked complexes of annular compound. The polarizer (122) is laminated with a retardation plate (121) to make the optical member (12), and the optical member (12) is arranged on one side or both sides of a liquid crystal cell (11) to make the liquid crystal display device (1). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a polarizer using a complex of a molecular tube and a conjugated polymer, a polarizing plate on which the polarizer is formed, an optical member using the polarizer, and a liquid crystal display device including the optical member.

  A liquid crystal display device has characteristics of low power consumption, operation at a low voltage, light weight and thinness, and is used in various display devices by taking advantage of these characteristics. The liquid crystal display device is composed of many materials such as a liquid crystal cell, a polarizing plate, a retardation plate, a light collecting sheet, a diffusion film, a light guide plate, and a light reflecting sheet. Therefore, by reducing the number of films and sheets that make up the liquid crystal display device, or by reducing the thickness of the film or sheet, improvements aimed at improving productivity, reducing weight, increasing brightness, etc. are prosperous. Has been done.

  Depending on the application, a product that can withstand severe durability conditions is required. For example, in a liquid crystal display device for a car navigation system, the temperature and humidity in the vehicle in which the liquid crystal display device is placed may increase. Therefore, compared with a monitor for a normal television or personal computer, the temperature and humidity. The conditions are severe. Therefore, for applications such as for car navigation systems, a polarizing plate that is highly durable is required.

  The polarizing plate usually has a structure in which a transparent protective film is laminated on both sides or one side of a polarizer made of a polyvinyl alcohol resin to which a dichroic dye is adsorbed and oriented. The polarizer is manufactured by a method in which a polyvinyl alcohol-based resin film is subjected to longitudinal uniaxial stretching and dyeing with a dichroic dye, followed by a crosslinking reaction by boric acid treatment, followed by washing with water and drying. As the dichroic dye, iodine or a dichroic organic dye is used. A polarizing plate is formed by laminating protective films on both or one side of the polarizer thus obtained, and the polarizing plate is used by being incorporated in a liquid crystal display device. As the protective film, a cellulose acetate resin film typified by triacetylrose is often used, and the thickness of the protective film is usually about 30 to 120 μm. In addition, an adhesive made of an aqueous solution of a polyvinyl alcohol-based resin is often used for laminating the protective film on the polarizer.

  A polarizing plate in which a protective film made of triacetyl cellulose is laminated on both sides or one side of a polarizer to which a dichroic dye is adsorbed and oriented via an adhesive made of an aqueous solution of a polyvinyl alcohol resin is long under wet heat conditions. When used for a long time, there are problems that the polarization performance is deteriorated and the protective film and the polarizer are easily peeled off.

  Therefore, there is an attempt to configure at least one protective film with a resin other than cellulose acetate. For example, Patent Document 1 describes that, in a polarizing plate in which protective films are laminated on both sides of a polarizer, at least one of the protective films is composed of a thermoplastic norbornene resin having a retardation film function. Yes. Patent Document 2 discloses that a protective film made of an amorphous polyolefin-based resin is laminated on one surface of a polarizer made of a polyvinyl alcohol-based resin film adsorbed and oriented with iodine or a dichroic organic dye, and the other surface. Describes a polarizing plate in which a protective film made of a resin different from an amorphous polyolefin resin, such as a cellulose acetate resin, is laminated. Furthermore, Patent Document 3 describes that a protective film made of a cycloolefin resin is laminated on a polyvinyl alcohol polarizer via an adhesive containing a urethane adhesive and a polyvinyl alcohol resin. Yes.

  However, amorphous polyolefin resins (also referred to as cycloolefin resins) such as norbornene resins have recently been put into practical use and are generally expensive. Amorphous polyolefin resins are easily eroded by organic solvents such as acetone, toluene, and ethyl acetate. Since these organic solvents are used for preparing the pressure-sensitive adhesive, they may remain in the pressure-sensitive adhesive. Furthermore, since the polarizing plate on which the protective film is laminated usually has a film thickness of 100 μm or more, it is difficult to follow the demand for remarkable thinning particularly in small and medium-sized applications.

  For example, OPTIVA manufactured by Nakan Co., Ltd. is known as a commercial product of a coating type thin film polarizing plate utilizing molecular crystallization. In Non-Patent Document 1, a high-concentration aqueous solution of a plurality of planar elliptical dye molecules is prepared using a material developed by OPTIVA, and Supramolecules in which the planar elliptical dye molecules are in columnar form are coated on a substrate. In addition, it is disclosed that a polarizing plate can be obtained by crystallization of the Supramolecules during the drying process. Since the polarizing plate disclosed in Non-Patent Document 1 is a coating type, it is possible to reduce the thickness of the polarizing plate, but it has been pointed out that the degree of polarization is low, it is brittle, and the water resistance is poor.

In recent years, a supramolecular structure in which a polymer is included with cyclodextrin has been studied (for example, see Non-Patent Document 2). In particular, a molecule-coated electric wire in which a polymer to be included is a conductive polymer has been developed (see, for example, Non-Patent Documents 3 to 6).
JP-A-8-43812 JP 2002-174729 A JP 2004-334168 A Omura, “Molecular Crystallized Thin Film Polarizer”, Monthly Display, August 2002, p. 17-19 Harada, “Chemistry of Polyrotaxane”, Contemporary Chemistry, March 1997, p. 26-31 Shimomura et al., “Molecular-coated conducting wire using conductive polymer and cyclodextrin”, Polymer Processing, 49 (8), p. 361-365 (2000) T.A. Shimomura et al., “Atomic force microscopic observation of insulated molecular formed by conducting polymer and molecular nanotube”. Chem. Phys. 116 (5), p. 1753-1756 (2002) Shimomura et al., “Molecular-coated wire using molecular nanotubes”, Surface Science, 23 (10), p. 634-640 (2002) Shimomura et al., “Conductive Nanofiber”, Polymer, 55 (3), p. 134-137 (2006)

  The present invention relates to a polarizer capable of satisfying a high degree of polarization, high durability, and good handleability simultaneously with a thin film, a polarizing plate on which the polarizer is formed, an optical member using the polarizer, and the An object of the present invention is to provide a liquid crystal display device including an optical member.

  The present invention relates to a polarizer comprising a complex composed of a molecular tube and a conjugated polymer having absorption in the visible light region enclosed by the molecular tube, wherein the complex is oriented substantially in one direction. .

  In the polarizer of the present invention, the light absorption peak wavelength of the composite is preferably in the range of 380 to 780 nm.

In the polarizer of the present invention, the conjugated polymer is preferably made of polyaniline.
In the polarizer of the present invention, the molecular tube is preferably composed of an intermolecular cross-linked product of a cyclic compound.

Moreover, it is preferable that this cyclic compound consists of cyclodextrins.
The present invention is also a production method for obtaining the above-mentioned polarizer, comprising a complex forming step of forming a complex composed of a molecular tube and a conjugated polymer included in the molecular tube, and the complex A polarizing material comprising: a fluid preparing step for preparing a fluid containing a liquid; and an aligning step in which the fluid is coated on a support substrate to form a polarizer in which the composite is oriented substantially in one direction. The present invention relates to a child manufacturing method.

  The present invention also relates to a polarizing plate in which the above polarizer is formed on a transparent resin film.

  In the polarizing plate of the present invention, the transparent resin film is preferably made of a cellulose derivative or a cyclic polyolefin.

  The present invention is also a production method for obtaining the above polarizing plate, a complex forming step of forming a complex composed of a molecular tube and a conjugated polymer included in the molecular tube, and the complex A fluid preparation step for preparing a fluid containing the same, and applying the fluid on a transparent resin film to form a polarizer having the composite oriented substantially in one direction on the transparent resin film And an alignment step for producing a polarizing plate.

  The present invention is also a production method for obtaining the above polarizing plate, a complex forming step of forming a complex composed of a molecular tube and a conjugated polymer included in the molecular tube, and the complex A fluid preparation step for preparing a fluid containing, an orientation step for applying the fluid on a support substrate to form a polarizer in which the composite is oriented substantially in one direction, and a polarizer. The present invention relates to a method for producing a polarizing plate comprising a joining step for joining a transparent resin film, and a separation step for separating a polarizer and a support substrate.

  The present invention also relates to an optical member comprising a laminate of the above polarizer and one or more optical layers.

In the optical member of the present invention, the optical layer preferably includes a retardation plate.
The present invention also relates to a liquid crystal display device comprising the above optical member and a liquid crystal cell, wherein the optical member is disposed on one side or both sides of the liquid crystal cell.

  The polarizer of the present invention has a stretched conformation because the conjugated polymer is included in the molecular tube. Therefore, according to the present invention, it is possible to obtain a polarizer having a high degree of polarization and excellent handleability. Further, since the mechanical strength and durability of the polarizer are good due to the inclusion of the conjugated polymer in the molecular tube, the polarizer of the present invention can be a coating type capable of thinning, According to the polarizing plate and the optical member using the polarizer, it is possible to obtain a liquid crystal display device having excellent display characteristics, light weight and excellent durability performance.

  The polarizer of the present invention includes a complex (hereinafter also simply referred to as a complex) composed of a molecular tube and a conjugated polymer having absorption in the visible light region enclosed by the molecular tube. Oriented in one direction. In the present invention, the molecular tube means a compound having a tubular molecular structure having a cavity inside, and the conjugated polymer means a polymer compound having conjugated multiple bonds in the molecule. In the composite contained in the polarizer of the present invention, the molecular tube encloses the conjugated polymer, so that the conformation in which the conjugated polymer extends in the cavity of the rigid molecular tube can be taken. The polarizer of the present invention has a high degree of polarization because such a complex is oriented substantially in one direction. Moreover, the handleability at the time of manufacture of a polarizer becomes favorable by taking the conformation which the conjugated polymer extended.

  In particular, when the molecular tube has a self-organizing ability such as liquid crystallinity or crystallinity, the complex can be oriented substantially in one direction by using the self-assembling ability. The polarizer can be formed. In addition, it is known that conjugated polymers are generally susceptible to oxygen and the like. However, in the present invention, the conjugated polymer is covered with a molecular tube. Thus, various durability performances such as heat resistance, moist heat resistance, and water resistance can be obtained satisfactorily. Therefore, by forming the polarizer of the present invention by a method such as coating alone, it is possible to obtain a light-polarized polarizing plate having excellent durability performance.

<Conjugated polymer>
Below, the conjugated polymer used by this invention is demonstrated. As the conjugated polymer, one conjugated polymer component may be used alone, or two or more conjugated polymer components may be used in combination. Conjugated polymers have absorption in the visible light region, typically in the form of a complex with a molecular tube that provides a light absorption peak wavelength in the visible light region, particularly in the range of 380-780 nm. Preferably molecules are used. Although it is necessary for the conjugated polymer to have absorption in the visible light region in constructing the polarizer of the present invention, even if the conjugated polymer gives a light absorption peak wavelength in the visible light region, Inclusion in the tube may shift the absorption peak in the complex state. Therefore, in defining the polarizer, it is practical to consider the light absorption peak wavelength of the composite. In the present invention, when two or more kinds of conjugated polymer components are used in combination, the light absorption peak wavelength of the composite is a superposition of light absorption spectra derived from each of these two or more kinds of conjugated polymer components. The wavelength at which the absorbance is maximum in the light absorption spectrum. The light absorption peak wavelength can be obtained from, for example, measurement of absorbance using a spectrophotometer.

  When the polarizer of the present invention is used in a liquid crystal display device, it is also useful to select the type and combination of conjugated polymer components so that the polarizer has absorption in the visible light region and the ultraviolet region. In this case, since the ultraviolet light absorbing ability is imparted to the polarizer, the liquid crystal molecules can be well protected from the ultraviolet light by the polarizer. When the polarizer is formed in the liquid crystal cell of the liquid crystal display device, the protective effect of the liquid crystal molecules is particularly great.

  When the polarizer of the present invention is used in a liquid crystal display device, the type and combination of the conjugated polymer component may be selected so that the polarizer has absorption in a broad wavelength region including almost the entire visible light region. it can. On the other hand, when a polarizer is combined with, for example, three color filters of red, green, and blue, the types and combinations of conjugated polymer components are selected so as to have an absorption wavelength corresponding to each of the three color wavelength regions. Three selected types of polarizers may be formed.

  Specific examples of the conjugated polymer component include trans-polyacetylene, cis-transoid polyacetylene, trans-cisoid polyacetylene, polyacetylene, polyphenylchloroacetylene, polyacetylene series such as poly (1,6-heptadiyne), polyparaphenylene, Polyphenylenes such as polymetaphenylene, polyphenylene vinylene, polyphenylene oxide, polyphenylene selenide, etc., heterocyclic polymers such as polypyrrole, polyselenophenone, polythiophene, polytellurophene, polyfuran, poly 2,5-pyridinediyl, polyaniline, poly Examples thereof include ionic polymer systems such as (3-methyl-4-carboxypyrrole) and ladder polymer systems such as polyacene and polyacenacene. Since each of these conjugated polymer components has a specific absorption wavelength, a polarizer corresponding to each absorption wavelength can be produced. Further, by combining a plurality of conjugated polymer components having different absorption wavelengths, the absorption wavelength can be broadened.

  The conjugated polymer component can be doped with, for example, alkali metals, metal salts, iodine, organic carboxylic acids, sulfonic acids, and the like. In this case, it is advantageous in that a conjugated polymer having a desired absorption wavelength can be obtained relatively easily.

  When a polarizer having an absorption wavelength almost in the entire visible light region is required, the conjugated polymer is particularly preferably made of polyaniline. Depending on its oxidation state, polyaniline is also called leuco emeraldine base (also called reduced polyaniline), emeraldine base (also called basic polyaniline oxidation (I) type) and pernigraniline base (aniline black oxidation (II) type) 3). The leuco emeraldine base has a sharp absorption around 340 nm, the emeraldine base has a broad absorption around 640 nm, and the pernigraniline base has a broad absorption around 540 nm. By appropriately controlling the abundance ratio of the polyaniline having the above three types of structures, for example, in a liquid crystal display device, ultraviolet rays that adversely affect liquid crystal molecules in a liquid crystal cell can be cut, and at the same time, an absorption band over the entire visible light region can be obtained. it can.

  The conjugated polymer is generally insoluble in water, but a conjugated polymer in which a hydrophilic functional group is introduced into the molecule to impart water solubility or water dispersibility can also be preferably used. In the case of using a hydrophilic conjugated polymer, water or a hydrophilic solvent can be used instead of the organic solvent at the time of producing the polarizer, which is preferable from the viewpoint of environmental protection. In the polarizer of the present invention, the conjugated polymer is chemically stabilized by being included in the molecular tube. Therefore, even when the conjugated polymer is given water solubility or water dispersibility, The water resistance of the child can be maintained well.

  Examples of the hydrophilic functional group include a sulfone group, an amino group, an amide group, an imino group, a quaternary ammonium base, a hydroxyl group, a mercapto group, a hydrazino group, a carboxyl group, a sulfate ester group, a phosphate ester group, or the like. And the like. By introducing a hydrophilic functional group into the molecule of the conjugated polymer, it becomes easier to dissolve in water or disperse in the form of fine particles in water, so that a water-soluble or water-dispersible conjugated polymer can be prepared. it can. In addition, the aqueous solution or aqueous dispersion of the conjugated polymer can contain a hydrophilic solvent in addition to water. Examples of the hydrophilic solvent include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-amyl alcohol, isoamyl alcohol, sec-amyl alcohol, tert-amyl alcohol. And alcohols such as 1-ethyl-1-propanol, 2-methyl-1-butanol, n-hexanol, and cyclohexanol.

  As a preferable molecular weight of the conjugated polymer, a weight average molecular weight in terms of polystyrene is within the range of 5,000 to 500,000. When the weight average molecular weight is 5000 or more, it is advantageous in that the molecular chain is long and the polarization degree and durability of the polarizer are better, and when it is 500,000 or less, a complex of a molecular tube and a conjugated polymer. It is advantageous in that it is excellent in handleability when orienting in substantially one direction.

  The weight average molecular weight in terms of polystyrene of the water-soluble or water-dispersible conjugated polymer is preferably 500,000 or less, more preferably 300,000 or less. When the weight average molecular weight is 500,000 or less, it is advantageous in that good water solubility or water dispersibility can be more easily realized and a complex with a molecular tube can be more easily formed. On the other hand, when the water-soluble or water-dispersible conjugated polymer has a weight average molecular weight in terms of polystyrene of 10,000 or more, and more preferably 50,000 or more, it is preferable from the viewpoint of good polarization degree and durability performance of the polarizer.

  Examples of commercially available water-soluble conjugated polymers include polyaniline sulfonic acid (manufactured by Mitsubishi Rayon Co., Ltd., weight average molecular weight of 150,000 in terms of polystyrene). Examples of commercially available water-dispersible conjugated polymers include polythiophene conductive polymers (manufactured by Nagase Chemtech, trade name: Denatron series).

<Molecular tube>
The molecular tube used in the present invention may be any tube as long as it is in a tube shape and can include a conjugated polymer. The inner diameter of the molecular tube is made larger than the outer diameter of the conjugated polymer. As a method of including a conjugated polymer in a molecular tube, the conjugated polymer is chemically stable in a state of being included in a molecular tube rather than a state in which the conjugated polymer is present alone. And a method for controlling the combination of the molecular structure of the molecular tube. For example, a method of designing the molecular tube and the conjugated polymer so that the site forming the inner wall of the molecular tube and the conjugated polymer have an intermolecular interaction is preferable. More specifically, in the case where a conjugated polymer that is hydrophobic as a whole molecule is included, a hydrophilic structure is formed at the site forming the outer wall of the tube, and a hydrophobic structure is formed at the site forming the inner wall of the tube. A method of combining molecular tubes having the following can be adopted. If the inner diameter of the molecular tube and the outer diameter of the conjugated polymer are close to each other in a combination in which the portion that forms the inner wall of the molecular tube and the conjugated polymer have intermolecular interactions, It is preferable because the molecules are considered to be easily included. For example, when polyaniline is used as the conjugated polymer and an intermolecular crosslinked body of cyclodextrin is used as the molecular tube, an intermolecular crosslinked body of β-cyclodextrin is preferably used.

  In addition, when using a conjugated polymer that combines multiple types of conjugated polymer components for the purpose of broadening the absorption wavelength of the polarizer and imparting ultraviolet absorbing ability to the polarizer, all types of conjugated polymer components In order to ensure good inclusion in the molecular tube, it is preferable to prepare a molecular tube corresponding to the molecular radius of each conjugated polymer component.

  Specific examples of the molecular tube include, for example, an intermolecular cross-linked product of a cyclic compound, and specifically, an intermolecular cross-linked product of cyclodextrin such as α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, and the like. Can be mentioned. In addition, esters, ethers, ether derivatives and salts of these cyclodextrins can also be used as cyclic compounds.

  The molecular tube used in the present invention can be formed by cross-linking the above cyclic compound in a cylindrical shape. A molecular tube using a cyclic compound as a raw material can be produced according to a known method, and a method of producing the molecular tube according to a method for producing a cyclodextrin polymer described in Japanese Patent No. 3288149 can be employed. To give a more specific example, first, a polyrotaxane having a structure in which a linear molecule is encapsulated in a ring of a cyclic compound such as α-cyclodextrin is prepared by a known method (for example, described in JP-A-6-25307). In the publication, the polyrotaxane is synthesized according to an α-cyclodextrin inclusion compound of a linear molecule). Next, the cyclic compound is intermolecularly cross-linked by a known means such as adding a cross-linking agent of a cyclic compound (for example, α-cyclodextrin) constituting the polyrotaxane. Thereafter, the blocking group of the linear molecule is removed by a known means using alkali or the like, and the molecular tube can be produced by extracting the linear molecule in the polyrotaxane. If desired, after removal of the blocking group, known purification means such as concentration, phase transfer, extraction, crystallization, dialysis, reprecipitation, etc. may be applied.

  In the above method, for example, epichlorohydrin, diisocyanate compound or the like can be used as the crosslinking agent. Further, as the alkali, for example, strong alkali or the like, more specifically sodium hydroxide, potassium hydroxide or the like can be used. Examples of linear molecules include aminated polyalkylene glycols such as polyethylene glycol bisamine, polyalkylene glycols such as polyethylene glycol, polypropylene glycol, and polytetrahydrofuran, and conjugated diene polymers such as polyisoprene and polybutadiene. Polydialkylsiloxanes such as polydimethylsiloxane, polyolefins such as polyethylene, polypropylene, and polyisobutylene can be used.

<Polarizer>
The polarizer of the present invention includes a complex composed of a molecular tube and a conjugated polymer. For example, when the polarizer of the present invention is formed and held on a transparent resin film to be a polarizing plate, the polarizer of the present invention can be composed of only a composite, In addition to the composite, a transparent resin having a binder ability such as an acrylic resin, a urethane resin, a polyester resin, or the like may be included. In this case, the shape retention ability in the state of the polarizer alone is better.

  In addition, it can confirm that the polarizer of this invention has the structure where the conjugated polymer was included in the molecular tube, for example by the measurement of the molecular size using AFM (atomic force microscope) etc.

<Polarizing plate>
The present invention also provides a polarizing plate in which the polarizer of the present invention described above is formed on a transparent resin film. In the present invention, the phrase “a polarizer is formed on a transparent resin film” means that the polarizer is formed on the surface of the transparent resin film directly or via another member. As the transparent resin film used in the present invention, a commercially available transparent resin film can be usually adopted. The transparent resin film may be formed by any film forming method. In particular, those having solvent resistance to a solvent capable of dissolving a complex of a molecular tube and a conjugated polymer are preferable. Further, it is desirable that the deformation such as shrinkage is small or not recognized at the processing temperature when forming the polarizer on the transparent resin film. Specifically, polyimide, epoxy resin, phenol resin, polyamide, polyetherimide, polyether ketone, polyether sulfone, polyphenylene sulfide, polyphenylene oxide, various polyesters, polyacetal, polycarbonate, various poly (meth) acrylates, triacetyl cellulose Examples thereof include cellulose derivatives such as polyvinyl alcohol, cyclic polyolefin and the like. Among these, it is particularly desirable to use a cellulose derivative such as triacetyl cellulose or a cyclic polyolefin. Moreover, although there is no restriction | limiting in the film thickness of a transparent resin film, about 20 micrometers-about 500 micrometers are preferable normally. The transparent resin film may be subjected to a stretching process.

  It is preferable that the surface that forms the polarizer in the transparent resin film has a substantially unidirectional orientation. In this case, it is advantageous in that the orientation of the polarizer can be further improved by forming the polarizer on the formation surface. A transparent resin film whose surface has been rubbed can be preferably used. In this case, a polarizer in which a complex of a molecular tube and a conjugated polymer is oriented in the rubbing direction can be formed. Further, when the transparent resin film is uniaxially stretched, the transparent resin film has a substantially unidirectional molecular orientation, and the complex of the molecular tube and the conjugated polymer is oriented in the molecular orientation direction. A polarizer can be formed.

  The transparent resin film may be one in which an alignment layer for aligning a complex of a molecular tube and a conjugated polymer is formed on the surface, and the alignment layer may be rubbed. As a material for forming the alignment layer, for example, a known material used as a low molecular liquid crystal aligning agent in a liquid crystal display device can be used. Specific examples include polyvinyl alcohol, various polyamic acids that can be polyimideized by heat treatment, polyimide, lecithin, various carboxylic acid chromium complexes, silane coupling agents, and obliquely deposited films of silicon oxide. Further, as the alignment layer subjected to the rubbing treatment, an alignment layer subjected to the rubbing treatment by a known method used for production of a normal liquid crystal display cell or the like can be used. In addition, since specific rubbing process conditions change with the materials of the rubbing cloth and transparent resin film, etc. to be used, appropriate conditions can be selected for each.

  Since the polarizer of the present invention has a good mechanical strength, the polarizer formed on the transparent resin film can be used as it is as a polarizing plate. However, depending on the application, the polarizer has two transparent resins. You may have the structure pinched | interposed with the film. In this case, the polarizer is satisfactorily protected by the two transparent resin films. Moreover, the polarizing plate of the present invention may further have an overcoat on the polarizer formed on the transparent resin film. In this case, the protective effect of the polarizer can be obtained by the overcoat. The material used for the overcoat is not particularly limited as long as it satisfies transparency, mechanical strength, and adhesiveness with a polarizer. Specifically, resins such as acrylic resin, urethane resin, and polyester resin can be suitably used.

<Manufacturing method of polarizer and polarizing plate>
Below, although the typical manufacturing method of the polarizer of this invention and a polarizing plate is demonstrated, this invention is not limited to this.

  The polarizer of the present invention includes, for example, a complex forming step for forming a complex composed of a molecular tube and a conjugated polymer included in the molecular tube, and a fluid preparation for preparing a fluid containing the complex. It can be manufactured by a method including a step and an alignment step of applying a fluid on a support substrate to form a polarizer in which the composite is substantially aligned in one direction. Below, the typical aspect of each process is demonstrated.

(Composite formation process)
As a method for preparing a complex of a molecular tube and a conjugated polymer, a method of including a conjugated polymer in a molecular tube after forming the molecular tube, or a ring part of a cyclic compound that is a raw material of the molecular tube. A method of forming a molecular tube by including a conjugated polymer and then cross-linking the cyclic compound between molecules can be preferably employed.

  First, a method of including a conjugated polymer in a molecular tube after forming the molecular tube will be described below. As a known method for producing a molecular tube, a molecular tube is produced by the method described above, the obtained molecular tube is dissolved in water or an organic solvent, and this is mixed with a solution or dispersion of a conjugated polymer. . The molecular tube used in the present invention has a function of enclosing the conjugated polymer. By selecting a combination of the molecular tube and the conjugated polymer, the conjugated polymer is encapsulated in the molecular tube by mixing as described above. Can be contacted to form a complex. In particular, when the conjugated polymer is mixed with the molecular tube in the state of a dispersion, it is preferable to combine the molecular tube and the conjugated polymer by performing ultrasonic treatment under heating after the above mixing. . Further, after the molecular tube and the conjugated polymer are combined, the terminal of the conjugated polymer or the terminal hole of the molecular tube may be chemically sealed. After the compounding or the end sealing, a known purification means such as concentration, transfer dissolution, extraction, crystallization, dialysis or reprecipitation may be used. By the above method, a complex in which the conjugated polymer is covered with the molecular tube can be obtained by the inclusion of the conjugated polymer in the molecular tube.

  Next, a method for forming a molecular tube by encapsulating a conjugated polymer in the ring of a cyclic compound that is a raw material of the molecular tube and then cross-linking the cyclic compound between molecules will be described. The molecular tube used in this method is in the form of a tube and can include the conjugated polymer in the same manner as the molecular tube used in the method of forming the molecular tube in advance and then combining the molecular tube and the conjugated polymer. Any thing can be used. Specifically, intermolecular cross-linked products of cyclodextrins such as α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin and the like can be mentioned. In addition, esters, ethers, ether derivatives and salts of these cyclodextrins can also be used as the cyclic compound.

  A typical method will be described by taking the case of using cyclodextrin as a cyclic compound as an example. For example, in a known method as described in JP-A-6-25307, a high conjugation is carried out inside a ring of cyclodextrin that is connected in large numbers. After synthesizing the polyrotaxane containing the molecule, the cyclodextrin is cross-linked by a known means such as adding a cross-linking agent, and then the blocking group of the polyrotaxane is removed by a known means using an alkali or the like. Is done. In the present invention, the blocking group may remain in the complex. After intermolecular crosslinking or removal of the blocking group, known purification means such as concentration, phase transfer, extraction, crystallization, dialysis, reprecipitation, etc. may be used.

  As the crosslinking agent, for example, epichlorohydrin, a diisocyanate compound or the like can be used. Further, as the alkali, for example, strong alkali or the like, more specifically sodium hydroxide, potassium hydroxide or the like can be used.

(Fluid preparation process)
Next, the composite produced by the method as described above is oriented substantially in one direction. As a method for orienting the composite, for example, a composite fluid is prepared by melting the composite or dissolving in a solvent, and the fluid is applied onto a support substrate, and the composite layer is formed. A forming method or the like may be employed. In the case of using a fluid obtained by melting the composite, the method of cooling and solidifying after applying the fluid, or in the case of using the fluid obtained by dissolving the composite in a solvent, The composite layers can be formed respectively by a method of drying after applying the fluid. The fluid is preferably a solution in which the complex is dissolved in a solvent capable of dissolving the complex of the conjugated polymer and the molecular tube in that the film thickness uniformity of the complex layer is good.

  The solvent used for the preparation of the above solution is not particularly limited as long as it can dissolve the complex and can be distilled off under appropriate conditions. Generally, ketones such as acetone, methyl ethyl ketone, isophorone, Ether alcohols such as 2-butoxyethyl alcohol, 2-hexyloxyethyl alcohol and 1-methoxy-2-propanol, glycol ethers such as ethylene glycol dimethyl ether and diethylene glycol dimethyl ether, esters such as ethyl acetate, methoxypropyl acetate and ethyl lactate , Phenols such as phenol and chlorophenol, amide solvents such as N, N-dimethylformamide, N, N-dimethylacetamide and N-methylpyrrolidone, halo such as chloroform, tetrachloroethane and dichlorobenzene Down solvents, water, and a solvent mixture of these systems can be used. Further, from the viewpoint of improving the film thickness uniformity of the composite layer, a surfactant, an antifoaming agent, a leveling agent and the like can be appropriately added to the solution.

(Orientation process)
The fluid prepared above is applied onto a support substrate to produce a polarizer in which the composite is oriented substantially in one direction. The material of the support substrate to which the fluid is applied is preferably one that can be rubbed and has heat resistance, polyethylene terephthalate, polyethylene naphthalate, polyphenylene sulfide, polyethersulfone, polyetheretherketone, polyimide, Cellulose derivatives and cyclic polyolefins are preferred. A long film or a sheet having an appropriate size can be used as the support substrate, but a long film is preferably used from the viewpoint of production efficiency.

  The method for applying the fluid containing the composite on the support substrate is not particularly limited, and examples thereof include spin coating, bar coating, roll coating, curtain coating, and slot coating and extrusion coating. A die coating method or the like can be employed. When using a solution of a composite as a fluid containing the composite, after applying the solution, the solvent is dried and removed by a method such as heating with a heater or blowing with warm air to form a composite layer.

  In the present invention, it is preferable to use an alignment support substrate whose surface is substantially aligned in one direction. In this case, it is advantageous in that the composite is more easily oriented by applying a fluid of the composite on the orientation support substrate, and a polarizer having a higher degree of polarization can be easily formed. As the orientation support substrate, a support substrate whose surface has been rubbed, a stretched film in which molecules are oriented in one direction by uniaxial stretching or the like can be preferably used.

  When the polarizer of the present invention is used as a polarizing plate by being formed on a transparent resin film, the transparent resin film may be used as a support substrate during the production of the polarizer.

  In the present invention, in order to make the orientation of the composite composed of the molecular tube and the conjugated polymer closer to perfection, the fluid containing the composite is dried in the above method and then subjected to heat treatment. Also good. The heat treatment temperature in this case cannot be generally stated because the optimum conditions and limit values differ depending on the liquid crystallinity and crystallinity of the complex of the conjugated polymer and the molecular tube to be used. More preferably, it can be in the range of 50 to 250 ° C, and more preferably in the range of 80 to 230 ° C. When the heat treatment temperature is 50 ° C. or higher, the fluidity of the complex of the conjugated polymer and the molecular tube is good, which is advantageous in that the complex can be oriented well. Further, when the heat treatment temperature is 300 ° C. or less, it is advantageous in that decomposition of the complex of the conjugated polymer and the molecular tube hardly occurs.

  The heat treatment time in the heat treatment can be usually in the range of 10 seconds to 2 hours, more preferably in the range of 30 seconds to 1 hour, and still more preferably in the range of 1 minute to 30 minutes. When the heat treatment time is 10 seconds or more, it is advantageous in that a desired alignment state can be satisfactorily completed, and when it is 2 hours or less, it is advantageous in that productivity is good.

  After the heat treatment, the orientation state of the composite can be fixed by cooling the composite layer. The method for cooling the composite layer is not particularly limited. Usually, after performing the heat treatment as described above, the entire orientation of the composite layer formed on the support substrate can be fixed by removing the support substrate on which the composite layer is formed at room temperature. Is possible. Also, depending on the type of complex of the conjugated polymer and the molecular tube, or from the viewpoint of productivity, the orientation state is fixed by using forced cooling means such as cold air blowing or contact with a cooling roll, for example. Also good.

  A polarizer having the composite substantially oriented in one direction can be obtained by the method as described above, but it is also useful to perform stretching as necessary. The film thickness of the polarizer is not particularly limited, and is not particularly limited as long as a desired degree of polarization can be obtained. For example, when used in the field of a liquid crystal display device or the like, usually, the film thickness is preferably 0.1 μm or more, more preferably 0.3 μm or more, and preferably 100 μm or less. When the film thickness is 0.1 μm or more, the film thickness of the polarizer can be controlled with high accuracy, and the function resulting from the structure in which the complex of the conjugated polymer and the molecular tube is oriented is exhibited well. This is advantageous. Moreover, when the film thickness is 100 μm or less, it is advantageous in that the alignment state of the composite is good and a polarizer having a good thickness can be obtained.

  When the polarizer formed on the support plate has self-supporting properties, the polarizer alone can be applied to various applications by peeling off the support substrate after forming the polarizer. Alternatively, a transparent resin film may be used as the support substrate, and a polarizer may be formed on the transparent resin film, for example, as a polarizing plate. On the other hand, when the polarizer does not have self-supporting property, a transparent resin film can be used as the support substrate, and the polarizer can be used on the transparent resin film, for example, as a polarizing plate.

  Even when a polarizer is formed on a support substrate such as a transparent resin film, depending on the optical characteristics of the support substrate, it is inappropriate to use the support substrate and the polarizer in combination as a polarizing plate. There is a case. In such a case, after forming the polarizer on the support substrate, the polarizer can be produced by transferring the polarizer to another appropriate transparent resin film and peeling off the support substrate. preferable.

  The transparent resin film used for supporting the polarizer to form a polarizing plate is preferably a transparent and optically isotropic film. Specifically, for example, polymethyl methacrylate, polystyrene, polycarbonate, poly Examples include ether sulfone, cyclic polyolefin, polyarylate, cellulose derivatives such as triacetyl cellulose, and colorless transparent polyimide. The thickness of the transparent resin film that supports the polarizer can usually be in the range of 0.1 μm to 10 mm, preferably in the range of 1 μm to 2 mm. If the thickness of the transparent resin film is within the above range, there will be no trouble in the final use.

  The method of transferring the polarizer to the transparent resin film is not particularly limited, but the polarizer formed on the support substrate and the transparent resin film are bonded together via an adhesive layer. If necessary, a method of peeling and removing the supporting substrate after the adhesive is cured may be preferably employed.

  The method for peeling and removing the support substrate is not particularly limited, but, for example, a method of artificially peeling the support substrate or the transparent resin film by sticking an adhesive tape to the corner end, a machine using a roll, etc. Peeling method, method of mechanical peeling after immersion in a poor solvent for all constituent materials, method of peeling by irradiating ultrasonic waves in the poor solvent, support substrate and transparent resin film / polarizer laminate The method of peeling by giving a temperature change using the difference in thermal expansion coefficient between and the like can be appropriately employed. For example, when the polarizer is obtained as a long roll film, the peeling transfer process as described above can be performed after the roll film is cut into a desired size. It is also possible to carry out as it is.

  There are no particular restrictions on the method of applying the adhesive used for the above-described release transfer, and the adhesive that can be used is not particularly limited, but depending on the end use, Optically isotropic may be desirable. Examples of the optically isotropic adhesive include acrylic adhesives, polyurethane adhesives, ethylene-vinyl acetate copolymer systems, various rubber adhesives, and various reactive adhesives. Can be mentioned. Examples of reactive adhesives include thermosetting, photocurable, or electron beam curable adhesives, and more specifically, those mainly composed of acrylic monomers and oligomers. Can be preferably used. In addition, various photopolymerization initiators, sensitizers, viscosity modifiers, and the like can be added to the adhesive as necessary. The curing method of the reactive adhesive is not particularly limited, and a photocuring method, an electron beam curing method, or the like can be appropriately employed, but it is desirable to carry out within a range that does not impair the orientation state of the polarizer. .

When the reactive adhesive is cured by a photocuring method, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a metal halide lamp, a xenon lamp, or the like can be used as a known curing means. Moreover, since the exposure amount of said hardening means changes with kinds of the reactive adhesive agent to be used, it cannot say unconditionally, Usually, it exists in the range of 50-2000 mJ / cm < ² >, Preferably it is 100-1000 mJ / cm < ² >. Can be within range.

  On the other hand, the acceleration voltage of the electron beam irradiated when the reactive adhesive is cured by the electron beam curing method is appropriately selected depending on the transmission power and curing power of the electron beam and cannot be generally described. However, it can be normally 30 to 1000 kV, preferably 50 to 500 kV.

  The polarizing plate of the present invention in which a polarizer is formed on a transparent resin film uses the transparent resin film as described above as a support substrate in the method for producing a polarizer as described above. It can be preferably manufactured by a method of forming a polarizer on the substrate, a method of forming a polarizer on a support substrate, and then transferring the polarizer onto a transparent resin film.

  First, a complex composed of a molecular tube and a conjugated polymer is formed by the complex formation step and the fluid preparation step as described above for the method for producing a polarizer, and a fluid containing the complex is further prepared. Next, the fluid is coated on the transparent resin film or the supporting substrate by any method such as a melt coating method or a solution coating method, and then dried to form a composite layer. Further, heat treatment and cooling are performed as necessary. The polarizer is formed on the transparent resin film or the support substrate by fixing the alignment state of the composite. A solution obtained by dissolving the complex in a solvent capable of dissolving the complex of the conjugated polymer and the molecular tube as described above is used as the fluid in that the film thickness uniformity of the polarizer is good. It is preferable. In this case, the polarizer can be formed by applying the fluid onto the transparent resin film or the support substrate by an appropriate application means as described above, and then removing the solvent by drying.

  When a polarizer is formed on the transparent resin film as described above, it may be used as it is as a polarizing plate. On the other hand, if the support substrate on which the polarizer is formed is not suitable as a polarizing plate, the polarizer can be transferred from the supporting substrate to a transparent resin film to form a polarizing plate. In this case, the polarizer and the transparent resin film The polarizer and the transparent resin film are bonded together by a method such as bonding them with an adhesive layer (bonding step), and if necessary, the adhesive is cured and then the polarizer is used to support the substrate. Is removed to separate the polarizer and the support substrate (separation step). As a more specific method of such peeling transfer, a polarizer is formed on the support substrate described above, and then the polarizer is transferred to a transparent resin film to peel the support substrate from the polarizer. A similar method can be adopted.

  When manufacturing a polarizing plate having an overcoat on a polarizer in the present invention, for example, a method of removing a solvent after applying a transparent resin varnish on the polarizer, a solventless UV curable resin, or a heat After coating the curable resin, an overcoat may be applied on the polarizer by a method such as ultraviolet irradiation or heat treatment.

<Optical member>
The present invention also provides an optical member comprising a laminate of the above-described polarizer of the present invention and one or more optical layers. Examples of the optical layer include a retardation plate, a light collecting sheet, a diffusion film, a light guide plate, a light reflection sheet, a brightness enhancement film, an antiglare sheet, and the like, and an optical member by combining these optical layers according to the purpose. Can have desired optical characteristics. The optical layer preferably includes a retardation plate. Specifically, a λ / 2 plate that changes the direction of linearly polarized light, a λ / 4 plate that forms circularly polarized light, or the like can be preferably used.

  Typical configurations of the optical member include, for example, a configuration in which a retardation plate, a polarizer (or polarizing plate), a diffusion film, a condensing sheet, a light guide plate, and a light reflection sheet are laminated in this order, a retardation plate, and polarization Examples include a configuration in which a polarizer (or polarizing plate) and a brightness enhancement film are stacked in this order, a configuration in which a retardation plate and a polarizer (or polarizing plate) are stacked in this order, and the like.

<Liquid crystal display device>
The present invention also provides a liquid crystal display device comprising the above-described optical member and a liquid crystal cell, wherein the optical member is disposed on one side or both sides of the liquid crystal cell. In producing the liquid crystal display device, an adhesive layer is formed on the surface of the optical member of the present invention as described above, and the optical member and the liquid crystal cell can be bonded via the adhesive layer. The liquid crystal cell constituting the liquid crystal display device includes various types known in the field of liquid crystal display devices such as TN (Twisted Nematic), STN (Super Twisted Nematic), VA (Vertical Alignment), and IPS (In-Plane Switching). Can be of mode. Note that the liquid crystal cell typically includes at least a pair of substrates, a pair of electrodes provided opposite to each other in a region sandwiched between the substrates, and a liquid crystal layer filled between the electrodes. Have

  FIG. 1 is a schematic cross-sectional view showing an example of a main part of the configuration of the liquid crystal display device of the present invention. The liquid crystal display device 1 includes a liquid crystal cell 11 and an optical member 12. The liquid crystal cell 11 is filled between a pair of substrates 111 and 112, a pair of electrodes 113 and 114 provided opposite to each other in a region sandwiched between the substrates 111 and 112, and the electrodes 113 and 114. Liquid crystal layer 115 formed. The optical member 12 is provided on the back side of the liquid crystal cell 11 and includes a phase difference plate 121 and a polarizer 122. A polarizer 132 is provided on the surface side of the liquid crystal cell 11. That is, in the configuration shown in FIG. 1, an optical member is formed on one side of the liquid crystal cell. In addition, each structural member can be mutually adhere | attached through an adhesive layer (not shown).

  FIG. 2 is a schematic sectional view showing another example of the main part of the configuration of the liquid crystal display device of the present invention. The liquid crystal display device 2 includes a liquid crystal cell 11 and an optical member 12 similar to those in FIG. 1, and further includes an optical member 13 including a retardation plate 131 and a polarizer 132 on the surface side of the liquid crystal cell 11. That is, in the configuration shown in FIG. 2, optical members are formed on both surfaces of the liquid crystal cell.

  FIGS. 1 and 2 show the case where the polarizer 132 is formed alone. However, in the liquid crystal display device of the present invention, the polarizer is formed on a transparent resin film instead of the polarizer. You may provide the polarizing plate formed in this. 1 and 2 show only a retardation plate and a polarizer as components of the optical member, but the optical member 12 includes, for example, a retardation plate and a polarizer (or a polarizing plate) in order from the liquid crystal cell side. , Diffusion film, condensing sheet, light guide plate, light reflection sheet laminated in this order, retardation plate, polarizer (or polarizing plate), brightness enhancement film laminated in this order, retardation plate and polarizer (Or a polarizing plate) may be stacked in this order. Moreover, the optical member 13 can be set as the structure by which the phase difference plate, the polarizer, and the anti-glare sheet were laminated | stacked in order from the liquid crystal cell side, for example. In addition, the laminated structure of the optical member and the liquid crystal cell in the liquid crystal display device of the present invention can be appropriately selected according to the purpose.

  The liquid crystal display device of the present invention may have a structure in which a polarizer is provided outside the liquid crystal cell as shown in FIGS. 1 and 2, and a structure in which the polarizer is provided inside the liquid crystal cell. You may have.

<Embodiment>
More specific embodiments of the present invention will be described below.

  For example, according to a method according to the method described in Non-Patent Document 4 described above, a complex of aniline black, which is a conjugated polymer, and a molecular tube derived from β-cyclodextrin can be synthesized. The resulting complex is dissolved in N-methylpyrrolidone to give a 5% by weight complex solution. On the other hand, an aqueous polyvinyl alcohol solution is cast on a triacetyl cellulose film, dried, and then rubbed to form a transparent resin film having an alignment layer on the surface. On the alignment layer, the composite solution obtained above is cast and dried to form the polarizer of the present invention comprising the composite layer. In the polarizer of the present invention, the fact that a complex composed of a molecular tube and a conjugated polymer is formed and that the complex is substantially oriented in one direction is, for example, AFM (atomic force microscope). ) By morphological observation. Furthermore, an overcoat can be formed by applying an acrylic ultraviolet curable resin to the surface of the polarizer and curing it by irradiating with ultraviolet rays. By the method as described above, a polarizing plate in which a polarizer is formed on a transparent resin film can be formed.

  The thickness of the polarizer obtained by the above method can be about 30 to 90 μm, and the degree of polarization can be about 90 to 100%. Therefore, according to the present invention, a polarizer having a thin film thickness and a high degree of polarization can be obtained.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The polarizer, polarizing plate and optical member of the present invention are suitably applied to liquid crystal display devices for various uses such as for car navigation systems, mobile phones, various monitors including personal computers, and televisions. Can be done.

It is a schematic sectional drawing which shows an example of the principal part of a structure of the liquid crystal display device of this invention. It is a schematic sectional drawing which shows another example of the principal part of a structure of the liquid crystal display device of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1, 2 Liquid crystal display device, 11 Liquid crystal cell, 12, 13 Optical member, 111,112 board | substrate, 113,114 electrode, 115 Liquid crystal layer, 121,131 Phase difference plate, 122,132 Polarizer.

Claims (13)

Comprising a complex comprising a molecular tube and a conjugated polymer having absorption in the visible light region enclosed by the molecular tube;
A polarizer, wherein the composite is substantially oriented in one direction.   The polarizer of Claim 1 which has the light absorption peak wavelength of the said composite_body | complex in the range of 380-780 nm.   The polarizer according to claim 1, wherein the conjugated polymer is made of polyaniline.   The polarizer in any one of Claims 1-3 in which the said molecular tube consists of an intermolecular bridge | crosslinking body of a cyclic compound.   The polarizer of Claim 4 in which the said cyclic compound consists of cyclodextrins. A manufacturing method for obtaining the polarizer according to claim 1,
A complex forming step of forming the complex composed of the molecular tube and the conjugated polymer included in the molecular tube;
A fluid preparation step of preparing a fluid containing the complex;
An alignment step of applying the fluid onto a support substrate to form a polarizer in which the composite is substantially aligned in one direction;
A method for producing a polarizer, comprising:   A polarizing plate, wherein the polarizer according to claim 1 is formed on a transparent resin film.   The polarizing plate according to claim 7, wherein the transparent resin film is made of a cellulose derivative or a cyclic polyolefin. A manufacturing method for obtaining the polarizing plate according to claim 7 or 8,
A complex forming step of forming the complex composed of the molecular tube and the conjugated polymer included in the molecular tube;
A fluid preparation step of preparing a fluid containing the complex;
An orientation process in which the fluid is applied onto the transparent resin film, and a polarizer in which the composite is oriented substantially in one direction is formed on the transparent resin film;
The manufacturing method of a polarizing plate containing. A manufacturing method for obtaining the polarizing plate according to claim 7 or 8,
A complex forming step of forming the complex composed of the molecular tube and the conjugated polymer included in the molecular tube;
A fluid preparation step of preparing a fluid containing the complex;
An alignment step of applying the fluid onto a support substrate to form a polarizer in which the composite is substantially aligned in one direction;
A bonding step of bonding the polarizer and the transparent resin film;
A separation step of separating the polarizer and the support substrate;
The manufacturing method of a polarizing plate containing.   An optical member comprising a laminate of the polarizer according to claim 1 and one or more optical layers.   The optical member according to claim 11, wherein the optical layer includes a retardation plate.   A liquid crystal display device comprising the optical member according to claim 11 and a liquid crystal cell, wherein the optical member is disposed on one side or both sides of the liquid crystal cell.

Images