Nitto-denko Corporation

Junzo Miyazaki

Shoichi Matsuda

Kyoko Nishiguchi

Toru Umemoto

Sadahiro Nakanishi

Tetsuo Inoue

Tatsuki Nagatsuka

Shouichi Matsuda

To obtain a water-resistant polarizing film free from deterioration in dichroic ratio caused by water-resistant treatment, it is critical that adjacent sulfonic acid groups or sulfonate groups in the organic dyes to be used for the polarizing film are spaced at moderate intervals. In a process for producing a water-resistant polarizing film of the present invention, the polarizing film before water-resistant treatment includes an organic dye which comprises an azo compoundrepresented by the following general formula (2) 

Process for producing water-resistant polarizing film

There is provided a method for producing a polarizing film having far superior water resistance to conventional polarizing films by contacting a liquid containing cationic polymers with a surface of a polarizing film.

Method for producing water-resistant polarizing film

There is provided a method for manufacturing a thin polarizing film having an absorption axis oblique to a width direction of the film which comprises the steps of: performing an orientation treatment in two directions in a plane of a support film; applying a solution containing a lyotropic liquid crystal compound onto a surface of the support film; and causing a column-shaped aggregate of the lyotropic liquid crystal compound to be oriented in a direction (orientation direction) equal to the vector sum of a direction of first orientation treatment and a direction of second orientation treatment.

Composite film and method for manufacturing a composite film

To obtain a water-resistant polarizing film free from deterioration in dichroic ratio caused by water-resistant treatment, it is critical that adjacent sulfonic acid groups or sulfonate groups in the organic dyes to be used for the polarizing film are spaced at moderate intervals. In a process for producing a water-resistant polarizing film of the present invention, the polarizing film before water-resistant treatment includes an organic dye which comprises an azo compound 20 represented by the following general formula (1) or (2) 

A birefringent film of the present invention comprises at least one kind of polycyclic compound including a &#x2014;COOM group (the M denotes a counter ion), wherein an index ellipsoid satisfies a relation of nz&#x3e;nx=ny. The polycyclic compound includes, for example, acenaphtho[1,2-b]quinoxaline derivative represented by the following general formula (I). The birefringent film of the present invention can be formed thin-type and have a high birefringent index in the thickness direction, since the birefringent film comprises the polycyclic compound. 

Birefringent film

Provided is a production method for a thin birefringent film with a satisfactory alignment property, in which a refractive index is controlled three-dimensionally and optical properties are unlikely to decrease in the case where the birefringent film is placed under high temperature and high humidity. The production method for a birefringent film of the present invention includes: the step (1) of preparing a solution that exhibits a nematic liquid crystal phase, containing at least one kind of polycyclic compound containing a &#x2014;SOM group and/or a &#x2014;COOM group (M represents a counter ion) and a solvent; the step (2) of preparing a base material at least one surface of which is subjected to a hydrophilization treatment; and the step (3) of applying the solution prepared in the step (1) to the surface of the base material prepared in the step (2), the surface being subjected to the hydrophilization treatment, followed by drying, in which a contact angle of water at 23&#xb0; C. on the surface of the base material prepared in the step (2), the surface being subjected to the hydrophilization treatment is 45&#xb0; or less.

Production method for birefringent film, birefringent film, and laminate

The present invention provides a birefringent film that hardly generates cracks even when the film is exposed under a high-temperature and high-humidity environment for a long period of time. The birefringent film of the present invention is a film containing, as a major component, a lyotropic liquid crystalline polycyclic compound containing an acenaphtho[1,2-b]quinoxaline derivative unit in a molecular structure and having a molecular weight of 500 or higher. The birefringent film of the present invention preferably has a refractive index ellipsoid showing a relationship of nx&#x2267;nz&#x3e;ny, and more preferably has an in-plane birefringence of 0.01 or higher at the wavelength of 590 nm.

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Ibaraki, Japan

Junzo Miyazaki