Liquid crystal display and method of manufacturing the same

Abstract

Disclosed herein is a liquid crystal display having a liquid crystal display element, the liquid crystal display element including: a pair of alignment films provided on mutually facing sides of a pair of substrates; and a liquid crystal layer which is provided between the pair of alignment films and contains a liquid crystal molecule having a negative dielectric anisotropy, wherein at least one of the pair of alignment films contains a cross-linked compound obtained by crosslinking a polymer compound having a cross-linkable functional group as a side chain, the liquid crystal layer further contains a molecule which has a ring structure and a spacer linking the ring structure, and the liquid crystal molecule is given a pre-tilt by the cross-linked compound.

What is claimed is: 
     
         1 . A liquid crystal display having a liquid crystal display element, the liquid crystal display element comprising:
 a pair of alignment films provided on mutually facing sides of a pair of substrates; and   a liquid crystal layer which is provided between the pair of alignment films and contains a liquid crystal molecule having a negative dielectric anisotropy, wherein   at least one of the pair of alignment films contains a deformed compound obtained by deforming a polymer compound having a photo-sensitive functional group as a side chain,   the liquid crystal layer further contains a molecule which has a ring structure and a spacer linking the ring structure, and   the liquid crystal molecule is given a pre-tilt by the deformed compound.   
     
     
         2 . The liquid crystal display according to  claim 1 , wherein the molecule which has the ring structure and the spacer linking the ring structure includes a nematic liquid-crystalline material or low-molecular material which has a negative or neutral dielectric anisotropy and contains at least one compound represented by the following formula:
   R1-A1-X1-A2-R2   
       where
 R1 and R2 are each an alkyl group of 1 to 10 carbon atoms or an alkenyl group of 2 to 10 carbon atoms, wherein one CH2 group or non adjacent two or more CH2 groups in the alkyl or alkenyl group may be replaced by an oxygen atom and/or a sulfur atom, and at least one hydrogen atom in the alkyl or alkenyl group may be replaced by a fluorine atom or a chlorine atom; 
 A1 and A2 are each independently trans-1,4-cyclohexylene group wherein one CH2 group or non-adjacent two CH2 groups may be replaced by an oxygen atom or a sulfur atom, or 1,4-phenylene group wherein one or more CH groups may be replaced by a nitrogen atom, or a group selected from the group including 1,4-cyclohexenylene group, 1,4-bicyclo[2,2,2]octylene group, pyperidin-1,4-diyl group, naphthalen-2,6-diyl group, decahydronaphthalen-2,6-diyl group, and 1,2,3,4tetrahydronaphthalen-2,6-diyl group, provided that hydrogen atoms in A1 and A2 may be replaced by CN or halogen; and 
 X1 is —CH2CH2-, —CH═CH—, —CH(CH3)CH2-CH2CH(CH3)-, —CH(CH3)CH(CH3)-, —CF2CFr, —CF═CF—, —CH20-, —OCHr, OCH(CH3)-, —CH(CH3)0-, —(CH2)4-, —(CH2)30-, -0(CH 2 )3-, —C═C—, —CF20-, —OCFr, —COO—, —COO—, —COS—, —SCO—, —O—, or —C—. 
 
     
     
         3 . The liquid crystal display according to  claim 1 , wherein the mass ratio of the molecule which has the ring structure and the spacer linking the ring structure to the total mass of the liquid crystal molecule and the molecule which has the ring structure and the spacer linking the ring structure is in the range of 1 to 50% by mass. 
     
     
         4 . The liquid crystal display according to  claim 1 , wherein the compound constituting at least one of the pair of alignment films includes a compound which further has, as a side chain, a group represented by the following formula (1):
   —R1-R2-R3  (1)
   
       where R1 is a straight chain or branched bivalent organic group of at least 3 carbon atoms and is linked to a main chain of the polymer compound, R2 is a bivalent organic group including a plurality of ring structures, wherein one of the atoms constituting the ring structures is linked to R1, and R3 is a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a univalent group having a carbonate group, or a derivative thereof. 
     
     
         5 . The liquid crystal display according to  claim 1 , wherein the compound constituting at least one of the pair of alignment films includes a compound which has, as a side chain, a group represented by the following formula (2):
   —R11-R12-R13-R14  (2)
   
       where R11 is a straight chain or branched bivalent organic group of 1 to 20 carbon atoms, preferably 3 to 12 carbon atoms, which may include an ether group or an ester group and which is linked to a main chain of the polymer compound, or R11 is an ether group or an ester group and is linked to the main chain of the polymer compound, R12 is an ethynylene group or a bivalent group including one type of structure selected from among chalcone, cyannamate, cyannamoyl, coumarin, maleimide, benzophenone, norbornene, oryzanol, and chitosan structures, R13 is a bivalent organic group including a plurality of ring structures, and R14 is a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a univalent group having a carbonate group, or a derivative thereof. 
     
     
         6 . The liquid crystal display according to  claim 1 , wherein
 the deformed compound obtained by deforming the polymer compound includes a side chain, and a main chain supporting the side chain on the substrate;   the side chain includes
 a deformed portion which is linked to the main chain and in which the side chain is partly deformed, and 
 a terminal structure portion linked to the deformed portion; and 
   the liquid crystal molecule is given the pre-tilt by being set along the terminal structure portion or being clamped by the terminal structure portion.   
     
     
         7 . The liquid crystal display according to  claim 1 , wherein
 the deformed compound obtained by deforming the polymer compound includes a side chain, and a main chain supporting the side chain on the substrate; and   the side chain includes
 a deformed portion which is linked to the main chain and in which the side chain is partly deformed, and 
 a terminal structure portion which is linked to the deformed portion and has a mesogenic group. 
   
     
     
         8 . The liquid crystal display according to  claim 1 , further comprising
 an orientation-regulating portion which includes a slit formed in an electrode or a projection provided on the substrate.