Heat resistant herapathite and process for producing the same.

摘要

A herapathite has a capillary crystal form in which its iodine atoms are oriented in a major axis direction of the capillary crystal form. The herapathite obtained is expressed by a chemical formula, xC20H24N2O2.yH2SO4.zHI3, in which a ratio of a number of the sulfuric acid molecules (y) with respect to a number of the iodine atoms (3z), i.e., (y/3z), is less than 0.5. The production process includes a reaction step, a first separating step, a recrystallizing step and a second separating step. A solvent used in the recrystallizing step is at least one of water and alcohol. A mixing weight ratio of water with respect to alcohol of the solvent is more than 50/50 or less than 10/90. The herapathite does not degrade even after it is heated up to 130 DEG C, and it is applicable to an automobile light shielding glass which should show a high transparency when a voltage is applied thereto.