STEEL MATERIAL FOR STRUCTURE EXCELLENT IN WEATHER RESISTANCE IN SEASHORE AND SURFACE TREATING AGENT

摘要

PROBLEM TO BE SOLVED: To develop a steel material for structure capable of exhibiting excellent weather resistance even under environment in which flying salt content is extremely large, e.g. in seashore areas or areas to which a snow-melting preventing agent/antifreezing agent is sprayed. SOLUTION: A surface-treating layer having 5-50μm film thickness and containing an Sn ion-feeding source substance (e.g. a divalent tin sulfate or tin oxide) feeding an acid-soluble Sn2+ion or Sn4+ion in an amount of 1-54 mass% expressed in terms of metal Sn into a binder resin (preferably butylal resin) is formed on the surface of the steel material for structure or on its rust layer in order to impart weather resistance to the steel material for structure. The surface-treating layer further can contain at least one kind of additional acid-soluble metal compound which becomes a feed source of Cu2+ion, Ni2+ion or Cr3+ion and a pigment. The surface treating agent further may form an organic resin layer having≥10μm film thickness and <100μm film thickness on the upper layer of the surface-treating layer. COPYRIGHT: (C)2007,JPO&INPIT