METHOD FOR PREPARING CHIRAL NEMATIC LIQUID CRYSTAL COMPOSITIONS AND LIQUID CRYSTAL DISPLAY ELEMENT

• Main Author: NOZAKI CHIYOJI
• Format: Patent
• Language: English
• Published: 21.05.2003
• Edition: 7
• Subjects: ADHESIVES; CHEMISTRY; DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING; DYES; FREQUENCY-CHANGING; MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FORELSEWHERE; METALLURGY; MISCELLANEOUS APPLICATIONS OF MATERIALS; MISCELLANEOUS COMPOSITIONS; NATURAL RESINS; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL LOGIC ELEMENTS; OPTICS; PAINTS; PHYSICS; POLISHES; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF

PROBLEM TO BE SOLVED: To provide a method for preparing chiral nematic liquid crystal compositions, whereby a plurality of chiral nematic liquid crystal compositions which need to have different selective reflection wavelengths are made to have different selective reflection wavelengths while they have substantially the same physical properties such as refringent anisotropy and dielectric anisotropy and to provide a liquid crystal display element having at least two liquid crystal layers containing chiral nematic liquid crystal compositions which have different selective reflection wavelengths and in which the properties such as refringent anisotropy and dielectric anisotropy are substantially the same among the chiral nematic liquid crystal compositions. SOLUTION: For example, when a chiral material C1 is added to a nematic liquid crystal N, the chiral material C1 used is one containing a mixture of enantiomers S and R which have optically active sites and directions of optical rotation opposite to each other. By making the mixing ratio of one enantiomer S in the mixture to the other enantiomer R in the mixture different from each other in each of liquid crystal compositions g1 and r1, the liquid crystal compositions g1 and r1 are made to have selective reflection wavelengths different from each other.