Liquid crystal display device and method for producing same

摘要

The present invention provides a liquid crystal display device that can prevent a decrease in the VHR and image sticking on the display screen because of residual DC voltage, and also can produce favorable alignment conditions; and a production method thereof. The liquid crystal display device of the present invention includes: a pair of substrates; a liquid crystal layer that contains liquid crystal molecules and is disposed between the pair of substrates; and an alignment film that is disposed on a liquid crystal layer side of at least one of the pair of substrates, the alignment film containing a polyamic acid or a polyimide with an imidization ratio of less than 100%, the liquid crystal display device including a monomolecular film on the alignment film.

主权项

1. A liquid crystal display device comprising:
a pair of substrates; a liquid crystal layer that contains liquid crystal molecules and is disposed between the pair of substrates; an alignment film between the liquid crystal layer and at least one of the pair of substrates, the alignment film containing a polyamic acid or a polyimide with an imidization ratio of less than 100%, and a monomolecular film between the liquid crystal layer and the alignment film, wherein the polyamic acid or the polyimide of the alignment film includes a photo-reactive functional group, wherein the monomolecular film includes a structure that is derived from a silane-based surfactant that contains the following chemical formula (1) or (3):
Cl3Si—(CR12)n—CR23  (1),orCl3Si—(CR12)n—NH2  (3), wherein each R1 is the same as or different from each other, wherein each R1 represents a hydrogen atom or a halogen atom, wherein each R2 is the same as or different from each other, wherein each R2 represents a hydrogen atom or a halogen atom, and wherein n represents an integer of 3 to 17, wherein the monomolecular film is a single layer formed of a same material that covers and is in contact with the entire surface of the alignment film so that the silane-based surfactant included in the monomolecular film reacts with carboxyl groups in the alignment film, to form a covalent bond that is between a structure derived from a carboxyl group in the alignment film and silicon in a structure derived from the silane-based surfactant, and is represented by the following chemical formula (2):thereby lowering the concentration of residual carboxyl groups contained in the alignment film without changing the imidization ratio, and
wherein a pretilt angle of the liquid crystal molecules satisfies at least one of 0°<θ≦8° and 81°<θ≦90° due to the alignment film having undergone a photo-alignment treatment after forming the monomolecular film, which results in minimal changes in aligning ability of the alignment film.