PROCESS FOR PRODUCTION OF BROAD-BAND CHOLESTERIC LIQUID CRYSTAL FILM

• Main Authors: MURAKAMI NAO, YOSHIMI HIROYUKI, ASANOI YOSHIAKI
• Format: Patent
• Language: English; Korean
• Published: 29.08.2012
• Subjects: CHEMISTRY; COMPOSITIONS BASED THEREON; 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; FREQUENCY-CHANGING; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; METALLURGY; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICAL LOGIC ELEMENTS; OPTICS; ORGANIC MACROMOLECULAR COMPOUNDS; PHYSICS; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; THEIR PREPARATION OR CHEMICAL WORKING-UP

The production method for a broadband cholesteric liquid crystal film having a reflection bandwidth of 300 nm or more includes the steps of: applying a liquid crystal composition containing a polymerizable mesogenic compound (a), a polymerizable chiral agent (b), and a thermal polymerization initiator (c) onto an alignment base material; and providing a broadband characteristic to the liquid crystal composition through thermal polymerization, and has the following feature (i) or (ii). (i) The thermal polymerization initiator (c) is contained in the liquid crystal composition at a ratio of 0.2 to 4 parts by weight with respect to 100 parts by weight of a total of the polymerizable mesogenic compound (a) and the polymerizable chiral agent (b). (ii) The thermal polymerization is carried out at a heating temperature of 70 to 150°C under an inert gas atmosphere containing oxygen at an oxygen concentration of 5 vol% or less.