| 摘要 |
PURPOSE:To facilitate the grade identification of the used catalysts by giving such durable marks which appear as colored symbols after drying and baking to the integral type or granular exhaust gas purification catalysts. CONSTITUTION:At the time of recovering or exchanging the used exhaust gas purification catalysts packed in automobile converters, etc., durable marks are put on the catalysts per so to permit at-a-glance identification of their grades. For example, in the case of the integral type catalysts, the required symbols are put by quick-dry type oily ink on the individual carriers prior to carrying of catalyst metals and are remained as dropped-out symbols after drying and baking or the symbols are put by using the solution containing a metal compound which colors after baking on the carrier surfaces carrying catalyst metals. In the case of granular catalysts, non-catalyst carrier particles which form the specified color after baking are mixed in slight amount into the catalysts, with the amount to be packed in a converter as one unit. |
