MANUFACTURE OF ALUMINUM BASE MATERIAL FOR LITHOGRAPHIC PRINTING PLATE AND ALUMINUM SUBSTRATE FOR LITHOGRAPHIC PRINTING PLATE

摘要

PURPOSE:To manufacture the titled substrate efficient in printing durability and water retention, by chemically etching the surface of specific aluminum alloy plate which is embossed. CONSTITUTION:The lithographic printing aluminum material having the unevenness of 0.3-1.0mum in surface roughness and 10-100mum in average diameter is obtained by embossing the surface of aluminum alloy plate containing 0.3- 1.5wt% Mg, 0.15-0.8wt% Si, 0.05-0.3wt% Mn or Cr if necessary and inevitable impurities. Then, the pit of 1-5mum in aperture diameter and 0.1-0.8mum in depth is formed by chemically etching the surface of this base material by 6-100g per m<2> with acid (for example: nitric acid).