| 摘要 |
PURPOSE:To obtain a can lid having sufficient corrosion resistance and pressure- resistant strength by applying heat treatment to a specific aluminum alloy plate after the final cold rolling processing thereof and applying a specific coating to the inner side surface of the can lid and baking the same to form a resin coating layer having a specific thickness. CONSTITUTION:The can lid of a can container is composed of an aluminum alloy plate having a thickness of 0.18-0.40mm containing Mg 2.8-6.0%, Cu 0.3% or less, Mn 0.5% or less, Fe 0.35% or less, Si 0.2% or less and inevitable impurities. After the final cold rolling processing of said alloy plate, heat treatment is applied to the alloy plate at 220-300 deg.C within one min and one kind of coating selected from thermosetting epoxy/phenol resin coating, thermosetting epoxy/urea resin coating, thermosetting vinyl resin coating and vinyl organosol resin coating is applied to the inner side surface of the can lid and baked to form a resin coating layer having thickness of 2-7mum. Since the aluminum alloy plate contains Mg, Cu, Mn, Fe and Si in a proper range, the stable can lid having good corrosion resistance and pressure-resistant strength and removed from strain while keeping corrosion resistance by the application of heat treatment is formed and, even when the thickness of the resin coating layer is 2-7mum, the corrosion resistance of the alloy plate is imparted. |
