Polarizing film, display device and production process thereof

A polarizing film comprising a substrate, and an optical alignment film and an optical absorption anisotropic film laminated on the substrate in this order,

• wherein the optical absorption anisotropic film has a content ratio of 30% by mass or less of a liquid crystalline non-colorable low molecular weight compound and is obtained by fixing the alignment of a dichroic dye composition comprising two or more nematic liquid crystalline dichroic dyes, wherein the dichroic dyes have a molecular length of 17 Å or more and an aspect ratio of 1.7 or more;
• in X-ray diffraction measurement thereof, diffraction peaks derived from periodic structure along a vertical direction to the alignment axis are present, the period indicated by at least one of the diffraction peaks is 3.0 to 15.0 Å and an intensity of the diffraction peak does not show a maximum value in the range of ±70° of the film normal line direction in a plane vertical to the alignment axis;
• and
• wherein said dichroic dye composition comprises two or more dichroic dyes which are selected from dichroic dyes represented by the following formula (II), the following formula (III), the following formula (IV) or the following formula (VI):
• wherein, R21 and R22 each represent a hydrogen atom, an alkyl group, an alkoxy group or a substituent represented by -L22-Y, provided that, at least one of them represents a group other than a hydrogen atom;
• L22 represents an alkylene group, and one CH2 group or non-adjacent two or more CH2 groups present in the alkylene group may each be substituted with —O—, —COO—, —OCO—, —OCOO—, —NRCOO—, —OCONR—, —CO—, —S—, —SO2—, —NR—, —NRSO2— or —SO2NR— and R represents a hydrogen atom or an alkyl group having 1 to 4 carbons;
• Y represents a hydrogen atom, a hydroxy group, an alkoxy group, a carboxyl group, a halogen atom or a polymerizable group;
• L21s each represent a linking group selected from the group consisting of an azo group (—N═N—), a carbonyloxy group (—C(═O)O—), an oxycarbonyl group (—O—C(═O)—), an imino group (—N═CH—) and a vinylene group (—C═C—);
• Dye each represents an azo dye residue represented by the following formula (IIa);
• in the formula (IIa), * represents a linkage part to L21;
• X21 represents a hydroxy group, a substituted or un-substituted alkyl group, a substituted or un-substituted alkoxy group, an un-substituted amino group or a mono or dialkylamino group;
• Ar21s each represent an aromatic hydrocarbon ring group optionally having a substituent or aromatic heterocyclic group optionally having a substituent;
• n represents an integer of 1 to 3, and when n is 2 or more, two Ar21s may be mutually the same or different;
• wherein, R31 to R35 each represent independently a hydrogen atom or a substituent;
• R36 and R37 each represent independently a hydrogen atom or an alkyl group optionally having a substituent;
• Q31 represents an aromatic hydrocarbon group optionally having a substituent, aromatic heterocyclic group optionally having a substituent or cyclohexane ring group optionally having a substituent;
• L31 represents a divalent linking group;
• A31 represents an oxygen atom or a sulfur atom;
• wherein, R41 and R42 each represent a hydrogen atom or a substituent, and may be mutually linked to form a ring;
• Ar4 represents an optionally substituted divalent aromatic hydrocarbon group or an optionally substituted aromatic heterocyclic group;
• R43 and R44 each represent a hydrogen atom or an optionally substituted alkyl group, and may be mutually linked to form a hetero ring;
• wherein, A1 and A2 each represent independently a substituted or un-substituted hydrocarbon ring group or a substituted or un-substituted hydrocarbon heterocyclic group.