PLANOGRAPHIC PRINTING PLATE

摘要

PURPOSE:To obtain good ink spread and extremely high printing durability by using such an aluminum plate as a supporting body that has a specified or large number of pits in a specified range of diameter per a specified area and that the average diameter of these pits is in a specified range, and by substantially bringing physical development nucleus in contact with an anodically oxidized layer. CONSTITUTION:An aluminum plate roughened and anodically oxidized can be easily inspected by photographing in about 50000 magnification by using a scanning electron microscope. The number of pits having 0.03-0.30mum diameter is specified to >=500 per 100mum<2> and the average diameter of pits having 0.03-0.30mum diameter is specified to 0.05-0.20mum. As for a pit except for a circular pit, its diameter is determined by calculating the diameter of a circular pit of the same area of the pit. The center depth of the pit is >=1/3 (0.01-0.10mum) of the diameter of the pit. Further, physical development nucleus is substantially brought into contact with the anodically oxidized layer.