Mitsui Toatsu Chemicals, Incorporated

Junichi Fujio

Tsutomu Nishizawa

Shin Hosonuma

Masakatsu Nakatsuka

Katsuji Nakamura

Yasuyuki Yamada

Kenichi Baba

Kozo Tanaka

Sin Hosonuma

Harue Suzuki

Disclosed is a polarizing film comprising a hydrophobic polymer containing a dichroic organic colorant in an oriented state which is characterized in that the dichroic organic colorant is substantially insoluble in water, organic solvents and liquid crystals and the dichroic ratio of the colorant is not less than 7 when it is measured with the film obtained by blending the colorant intimately with polyethylene terephthalate, melting the resulting blend and forming it into a film. This polarizing film has exceptionally excellent moisture resistance and thermal resistance.

Polarizing film

Disclosed is a colored polarizing film having excellent durability which comprises (a) an organic polymer film or sheet and (b) at least one dichroic dye having an azo, anthraquinone, thioindigo, perylene or phthalone structure containing no water-soluble group. Also disclosed is a method of making a colored polarizing film using an organic polymer film or sheet formed of a polyamide or polyester resin, which comprises the steps of (a) blending (preferably, dry blending) a dichroic dye with the resinous polymer in advance, (b) melting the resulting blend and forming it into a film, and then (c) stretching the film in at least one direction.

Colored polarizing film and method of making same

Disclosed is a polarizing film containing a base resin and a photodichroic material which is characterized in that (1) the uniaxial orientation coefficient (f) of the principal crystal axis which is a crystal axis parallel to the molecular chain of the base resin, with respect to the reference axis is not less than 0.7 and (2) when a specimen of the polarizing film is cut out so as to have a surface perpendicular to the reference axis and X-rays impinging on the specimen parallel to the reference axis, the product (f.times.R) of the aforesaid uniaxial orientation coefficient (f) and the proportion (R=(I.sub.min /I.sub.max).times.100) of the minimum value (I.sub.min) to the maximum value (I.sub.max) of diffracted X-ray intensity on the resulting Debye-Scherrer ring is not less than 10. This polarizing film has excellent thermal resistance and moisture resistance and gives a high degree of polarization.

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Nagoya, Japan

Junichi Fujio