Passivating solution and surface treatment method for galvanized material

Abstract

The invention relates to a passivating solution which is aqueous solution containing water-soluble molybdic compound, boric acid, water-soluble organic matter and silica sol, wherein the water-soluble organic matter is a mixture of alcohol and organic carboxylic acid. The invention also provides a surface treatment method for a galvanized material, which comprises the following step: enabling the passivating solution to be in contact with a galvanized material. A galvanized layer can be passivated by the contact between the passivating solution and the galvanized material so as to enable the galvanized material to have excellent corrosion resistance. In addition, the paint composition is chromium free and meets the requirements of a RoHS instruction.

Description

technical field

[0001] The invention relates to a passivation solution and a surface treatment method for galvanized materials. Background technique

[0002] One of the main uses of galvanized materials such as galvanized steel sheets or steel coils is in the electrical manufacturing industry, such as air conditioners and computer cases. Galvanized materials are generally passivated prior to storage, transport or use. Passivation treatment generally includes contacting the passivation solution with the galvanized material, such as spraying the passivation solution onto the surface of the galvanized material. The passivation solution includes a passivation solution containing hexavalent chromium and a passivation solution without hexavalent chromium. liquid.

[0003] On February 13, 2003, the European Parliament and the Council passed the "Directive on the Restriction of the Use of Certain Hazardous Substances in Electrical and Electronic Equipment", referred to as the RoHS...