Abstract: As the polarizing fiber of the present invention, the cross sectional form perpendicular to the longitudinal direction has a sea-island structure, and the cross sectional form is continuously made up in the longitudinal direction. A resin (sea component) that constitutes the sea region of the sea-island structure comprises a dichroic dye, and a resin (island component) that constitutes the island regions of the sea-island structure is a transparent resin. The polarizing fiber of the present invention may be used as a forming material of a polarizer, for example. By using the above polarizing fiber, a polarizer wherein unevenness of the transmittance is small and cracks are less generated may be formed.

Abstract: A method for producing a polarizing film includes a step (1) of preparing a lyotropic liquid crystalline solution having electric conductivity of not more than 50 ?S/cm (expressed in terms of 0.05% by weight) and containing a dichroic dye and a solvent, a step (2) of preparing a base material having at least one surface subjected to a hydrophilization treatment, and a step (3) of coating the solution prepared in the step (1) on the hydrophilized surface of the base material prepared in the step (2) at a coating rate of not less than 100 mm/second, and drying the solution. The polarizing film produced in the method has a dichroic ratio of 25 or more at a wavelength of 600 nm.

Abstract: An object of the present invention is to provide a thin optical laminate a refractive index of which is three-dimensionally controlled. The optical laminate of the present invention comprises a retardation layer containing a polycyclic compound having at least one of a —SO3M group and a —COOM group, and having an index ellipsoid satisfying a relationship of nx?nz>ny; and a retardation layer having an index ellipsoid satisfying a relationship of nx?ny>nz. As the polycyclic compound, for example, a quinoxaline derivative represented by the following formula (I) is used.

Abstract: The present invention provides a method of producing an optical laminate that can produce an optical laminate including an applied film containing a lyotropic liquid crystalline compound so that the thickness of the applied film will be approximately uniform. A method of producing an optical laminate having a base material and an applied film, comprising the step of applying a solution containing at least one kind of lyotropic liquid crystalline compound on the base material so as to form the applied film, wherein the concentration of the lyotropic liquid crystalline compound in the solution is lower than the isotropic phase—liquid crystal phase transition concentration. For example, the concentration of the lyotropic liquid crystalline compound in the solution is from (CIN?18)% by mass to (CIN?1)% by mass, where CIN represents the isotropic phase-liquid crystal phase transition concentration.

Abstract: A process for the producing a coating fluid of the present invention comprises a step of adjusting a pH of the coating fluid by mixing ammonium hydroxide into an acid solution containing a lyotropic liquid crystal compound and a solvent. Further, a process for the producing an optically anisotropic film of the present invention comprises a step of obtaining an optically anisotropic film by casting the coating fluid produced by the aforementioned process for production of the coating fluid in a thin film state, followed by drying.

Abstract: The present invention provides a method of producing an optical laminate that can produce an optical laminate including an applied film containing a lyotropic liquid crystalline compound so that the thickness of the applied film will be approximately uniform. A method of producing an optical laminate having a base material and an applied film, comprising the step of applying a solution containing at least one kind of lyotropic liquid crystalline compound on the base material so as to form the applied film, wherein the concentration of the lyotropic liquid crystalline compound in the solution is lower than the isotropic phase-liquid crystal phase transition concentration. For example, the concentration of the lyotropic liquid crystalline compound in the solution is from (CIN?18)% by mass to (CIN?1)% by mass, where CIN represents the isotropic phase-liquid crystal phase transition concentration.

Abstract: As the polarizing fiber of the present invention, the cross sectional form perpendicular to the longitudinal direction has a sea-island structure, and the cross sectional form is continuously made up in the longitudinal direction. A resin (sea component) that constitutes the sea region of the sea-island structure comprises a dichroic dye, and a resin (island component) that constitutes the island regions of the sea-island structure is a transparent resin. The polarizing fiber of the present invention may be used as a forming material of a polarizer, for example. By using the above polarizing fiber, a polarizer wherein unevenness of the transmittance is small and cracks are less generated may be formed.

Abstract: An object of the present invention is to provide a thin optical laminate a refractive index of which is three-dimensionally controlled. The optical laminate of the present invention comprises a retardation layer containing a polycyclic compound having at least one of a —SO3M group and a —COOM group, and having an index ellipsoid satisfying a relationship of nx?nz>ny; and a retardation layer having an index ellipsoid satisfying a relationship of nx?ny>nz. As the polycyclic compound, for example, a quinoxaline derivative represented by the following formula (I) is used.

Abstract: A process for the producing a coating fluid of the present invention comprises a step of adjusting a pH of the coating fluid by mixing ammonium hydroxide into an acid solution containing a lyotropic liquid crystal compound and a solvent. Further, a process for the producing an optically anisotropic film of the present invention comprises a step of obtaining an optically anisotropic film by casting the coating fluid produced by the aforementioned process for production of the coating fluid in a thin film state, followed by drying.

Abstract: A polarizing film formed by orienting organic dyes composed of a lyotropic liquid crystal compound, which comprises an acenaphtho[1,2-b]quinoxaline-base compound, wherein the content of the acenaphtho[1,2-b]quinoxaline-base compound is less than 10 weight parts with respect to 100 weight parts of the organic dyes.

Abstract: A method for producing a polarizing film of the present invention comprises a step (1) of preparing a lyotropic liquid crystalline solution having electric conductivity of not more than 50 ?S/cm (expressed in terms of 0.05% by weight) and containing a dichroic dye and a solvent, a step (2) of preparing a base material having at least one surface subjected to a hydrophilization treatment, and a step (3) of coating the solution prepared in the step (1) on the hydrophilized surface of the base material prepared in the step (2) at a coating rate of not less than 100 mm/second, and drying the solution. The method of the present invention can easily produce a polarizing film having a high dichroic ratio.