| abstract |
PURPOSE: To make such fast marking that is normally transparent and may be checked when a lens made of ethylene glycol bisallylcarbonate is fogged by breathing by marking part of said lens with a silver sulfate-contg. concd. surfuric acid. n CONSTITUTION: A character (H) is drawn with a writing brush on a spectacle lens made of ethylene glycol bisallylcarbonate "(CR39)" by using a concd. sulfuric acid (97%) dissolved with 0.1% silver sulfate, and is left standing for 15min at 25°C, after which it is washed. The resulted lens is exactly the same as a vormal lens, but when it is fogged by breathing, only the part of the character becomes transparent, thus enabling the mark to be checked. Even when the mark is subjected to ultraviolet ray irradiation for 200hr with a weatherometer, it causes no changes and even when it is rubbed 5,000 times with tissue paper, it does not show any change, thus the mark is fast. n COPYRIGHT: (C)1981,JPO&Japio |