Single-Face Electrogalvanized, Chromium-Free Surface Treated Steel Plate for Fuel Tank and Surface Treatment Agent

摘要

The invention relates to an inorganic aqueous surface treatment agent for a single-face electrogalvanized, chromium free surface treated steel plate, a single-face electrogalvanized, chromium-free surface treated steel plate used for fuel tanks and a process of making the same. The inorganic aqueous surface treatment agent for a single-face electrogalvanized, chromium free surface treated steel plate comprises the following components: one or more metallic ion compounds comprising at least one of Zn2+, Mn2+, Mg2+, Ni2+, Al3+ and Ca2+; one or more vanadium compounds comprising at least one of V4+ and V5+; one or more compounds comprising at least one of phosphoric acid, pyrophosphoric acid, metaphosphoric acid, organic phosphoric acid and the ammonium salts thereof; one or more fluoric acid compounds comprising at least one of Zr, Ti, Si and Ha; one or more silane coupling agents comprising at least one of vinyl silane coupling agent, amino silane coupling agent, epoxy silane coupling agent and acryloxy silane coupling agent; a silica sol having a particle diameter less than 100 nm; one or more surfactants comprising at least one of carboxylate, sulfuric acid ester salt, sulfonate and phosphoric acid ester salt; wherein the total solid content in the inorganic aqueous surface treatment agent is 2 wt %-20 wt % of the surface treatment agent. The process for preparing the single-face electrogalvanized chromium-free surface treated steel plate used for fuel tanks comprises the steps of coating the plated surface of the single-face electrogalvanized steel plate with the above surface treatment agent, solidifying at a temperature of 70-100° C., and finally oil finishing on the surface to produce a skin film resulting from the surface treatment with a weight of 100-600 mg/m2.

主权项

1. An inorganic aqueous surface treatment agent for a single-face electrogalvanized, chromium free surface treated steel plate, formulated by dissolving or dispersing each component in an aqueous medium, wherein the aqueous solution comprises the following components:
(A) one or more metallic ion compounds comprising at least one of the ions of Zn2+, Mn2+, Mg2+, Ni2+, Al3+ and Ca2+, wherein the molar concentration of the metallic ion in the surface treatment agent is 0.01-0.3 mol/L; (B) one or more vanadium compounds comprising at least one of a compound comprising V4+ and a compound comprising V5+, wherein the molar concentration of V element in the surface treatment agent is 0.005-0.08 mol/L; (C) one or more compounds comprising at least one of phosphoric acid, pyrophosphoric acid, metaphosphoric acid, organic phosphoric acid and the ammonium salts thereof, wherein the molar concentration of P element in the surface treatment agent is 0.05-1 mol/L; (D) one or more fluoric acid compounds comprising at least one of Zr, Ti, Si and Ha, wherein the fluoric acid compound comprises 6 fluorine atoms, and the molar concentration of F element in the surface treatment agent is 0.01-0.2 mol/L; (E) one or more silane coupling agents comprising at least one of vinyl silane coupling agent, amino silane coupling agent, epoxy silane coupling agent and acryloxy silane coupling agent, wherein the molar concentration of the silane coupling agent in the surface treatment agent is 0.1-0.5 mol/L; (F) a silica sol having a particle diameter less than 100 nm, wherein the molar concentration of its Si element in the surface treatment agent is 0.01-0.2 mol/L; (G) one or more surfactant comprising at least one of carboxylate, sulfuric acid ester salt, sulfonate and phosphoric acid ester salt, wherein the molar concentration of the surfactant in the surface treatment agent is 0.0001-0.003 mol/L; wherein the total solid content in the inorganic aqueous surface treatment agent is 2 wt %-20 wt % of the surface treatment agent.