Liquid crystal display

A liquid crystal display comprising:

• a pair of substrates;
• a liquid crystal layer placed between a pair of the electrodes;
• electrodes provided on at least one of the substrates to apply an electrical field to the liquid crystal layer;
• active elements each connected to each of the electrodes;
• and
• a photo-reactive alignment layer placed between the liquid crystal layer and at least one of the substrates,
• wherein the electrodes include a common electrode and a source electrode,
• the common electrode or the source electrode is formed on an insulation film,
• the photo-reactive alignment layer is formed on the insulation layer and the common electrode or the source electrode,
• the polarized light used for the alignment treatment of the photo-reactive alignment layer has a light wavelength of 200 to 400 nm,
• the photo-reactive alignment layer contains a polyamic acid or polyimide composed of cyclobutanetetracarboxylic dianhydride or a derivative thereof and diamine compound,
• the cyclobutanetetracarboxylic dianhydride or derivative thereof contains at least one species selected from the group consisting of those represented by the general formulae [Compound 1] to [Compound 3]:
• (wherein, R1 to R4 are independently hydrogen, fluorine, chlorine or bromine atom, phenyl group, an alkyl group or alkoxy group of 1 to 6 carbon atoms, vinyl group [—(CH2)m—CH═CH2, m is 0, 1 or 2] or acetylene group [—(CH2)m—CH≡CH, m is 0, 1 or 2]),
• the diamine compound contains at least one species selected from the group consisting of those represented by the general formulae [Compound 4] to [Compound 18], [Compound 21] to [Compound 22] and [Compound 44]:
• (wherein, R1 to R8 for Compounds 4 to 18 are independently hydrogen, fluorine or chlorine atom, an alkyl group or alkoxy group of 1 to 6 carbon atoms, vinyl group [—(CH2)m—CH═CH2, m is 0, 1 or 2] or acetylene group [—(CH2)m—C═CH, m is 0, 1 or 2];
• X for Compounds 10 to 12 is —CH2—, —NH—, —CO—, —O— or —S— as a coupling group;
• and R1 for Compounds 21 and 22 are independently an alkyl group of 1 to 6 carbon atoms).

A liquid crystal display comprising:

• a pair of substrates;
• a liquid crystal layer placed between a pair of the electrodes;
• electrodes provided on at least one of the substrates to apply an electrical field to the liquid crystal layer;
• active elements each connected to each of the electrodes;
• and
• a photo-reactive alignment layer placed between the liquid crystal layer and at least one of the substrates,
• wherein the electrodes include a common electrode and a source electrode,
• the common electrode or the source electrode is formed on an insulation film,
• the photo-reactive alignment layer is formed on the insulation layer and the common electrode or the source electrode,
• a polarized light used for alignment treatment of the photo-reactive alignment layer has a light wavelength of 200 to 400 nm,
• the photo-reactive alignment layer contains a polyamic acid or polyimide composed of cyclobutanetetracarboxylic dianhydride or a derivative thereof and diamine compound,
• the cyclobutanetetracarboxylic dianhydride or derivative thereof contains at least one species selected from the group consisting of those represented by the general formulae [Compound 2] or [Compound 3]:
• (wherein, R1 to R4 are independently hydrogen, fluorine, chlorine or bromine atom, phenyl group, an alkyl group or alkoxy group of 1 to 6 carbon atoms, vinyl group [—(CH2)m—CH═CH2, m is 0, 1 or 2] or acetylene group [—CH(CH2)m—C≡CH, m is 0, 1 or 2],
• the diamine compound contains at least one species selected from the group consisting of those represented by the general formulae [Compound 4] to [Compound 22]:
• (wherein R1 to R8 for Compounds 5 to 18 are independently hydrogen, fluorine or chlorine atom, an alkyl group or alkoxy group of 1 to 6 carbon atoms, vinyl group [—(CH2)m—CH═CH2, m is 0, 1 or 2] or acetylene group [—CH(CH2)m—C≡CH, m is 0, 1 or 2];
• X for Compounds 10 to 12 is —CH2—, —NH—, —CO—, —O— or —S— as a coupling group;
• and R1 for Compounds 21 and 22 are independently an alkyl group of 1 to 6 carbon atoms);
• R1 and R2 for Compounds 4, 19 and 20 are independently hydrogen, fluorine or chlorine atom, an alkyl group or alkoxy group of 1 to 6 carbon atoms, vinyl group [—(CH2)m—C═CH, m is 0, 1 or 2] or acetylene group [—(CH2)m—C≡CH, m is 0, 1 or 2];
• and R3 and R4 for Compound 20 are independently an alkyl group of 1 to 6 carbon atoms).