Polarizing film

Claim 2

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 has a solubility in water, organic solvents and liquid crystals of not greater than 0.05% by weight at about 25° C. 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.

Claim 3

A polarizing film as claimed in claim 1 wherein the film base resin contains not less than 80% by weight of at least one polymer selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate and polybutylene terephthalate.

Claim 4

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, which is compound represented by the formula ##STR198## where X 1 , X 2 , X 3 , X 4 , X 5 , and X 6 represent hydrogen atoms, halogen atoms, hydroxyl groups or amino groups that may be substituted by an alkyl group of 1 to 3 carbon atoms, and at least one of X 1 , X 2 , X 3 and X 6 is a hydroxyl group or an imino group that may be substituted by an alkyl group of 1 to 3 atoms; Z represents an oxygen atom, a sulfur atom or an amino group; R 1 and R 2 independently represent hydrogen atoms, halogen atoms, methyl groups or methoxy groups; and n represents an integer of 1, 2 or 3; when n is an integer of 1, R 3 represents ##STR199## when n is an integer of 2 or 3, R 3 represents --COOH, --COOR 4 , --CONH 2 , --CONHR 4 , --OOCR 4 , --NHCOR 4 , --N═N--R 4 , in which R 4 is a phenyl, biphenyl or naphthalene radical that may be substituted by R 1 , R 2 , --COOH and/or --COOCH 3 , and ring A is a phenyl, biphenyl or naphthalene radical that may be substituted by R 1 , R 2 , --COOH and/or --COOCH 3 or an anthraquinone radical that may be substituted by X 2 , X 3 , X 4 , X 5 , and/or X 6 , has a solubility in water, organic solvents and liquid crystals of not greater than 0.05% by weight of about 25° C., 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.

Claim 5

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, which is compound represented by the formula ##STR198## where X 1 , X 2 , X 3 , X 4 , X 5 , and X 6 represent hydrogen atoms, halogen atoms, hydroxyl groups or amino groups that may be substituted by an alkyl group of 1 to 3 carbon atoms, and at least one of X 1 , X 2 , X 3 and X 6 is a hydroxyl group or an imino group that may be substituted by an alkyl group of 1 to 3 atoms; Z represents an oxygen atom, a sulfur atom or an amino group; R 1 and R 2 independently represent hydrogen atoms, halogen atoms, methyl groups or methoxy groups; and n represents an integer of 1, 2 or 3; when n is an integer of 1, R 3 represents ##STR199## when n is an integer of 2 or 3, R 3 represents --COOH, --COOR 4 , --CONH 2 , --CONHR 4 , --OOCR 4 , --NHCOR 4 , --N═N--R 4 , in which R 4 is a phenyl, biphenyl or naphthalene radical that may be substituted by R 1 , R 2 , --COOH and/or --COOCH 3 , and ring A is a phenyl, biphenyl or naphthalene radical that may be substituted by R 1 , R 2 , --COOH and/or --COOCH 3 or an anthraquinone radical that may be substituted by X 2 , X 3 , X 4 , X 5 , and/or X 6 , has a solubility in water, organic solvents and liquid crystals of not greater than 0.05% by weight of about 25° C., 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.

Claim 6

A polarizing film as claimed in claim 3 wherein the film base resin contains not less than 80% by weight of at least one polymer selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate and polybutylene terephthalate.