PRODUCTION OF DOUBLE REFRACTION PLATE

摘要

PURPOSE:To obtain inexpensively a double refraction plate having a large area by working a transparent block of a network polymer thereby obtaining the double refraction plate. CONSTITUTION:A transparent block 3 of a network polymer is obtd. by using bisphenol A diglycidyl-ether as a principal material and methyl nadic acide anhydride as a hardener and curing the mixture for 4hr at 80 deg.C then heat-treating the same for 15hr at 150 deg.C. The block 3 is heated with a heater 4a of a thermal compression device 4 and is compressed under the external force exterted thereon in an Av-Av' direction by a compression plate 4b. The molding is then cooled to an ordinary temp., whereby an optically anisotropic block 3' is obtd. The double refraction plate having a large area is inexpensively obtd. by cutting the block 3' so as to have a desired angle theta and thickness (t) to the optical axis Oa.