NEUTRAL DETERGENT AND HOW TO CONFIGURE A PROCESS AT THE CONTINUOUS PAINTING LINE

摘要

The present invention provides a neutral detergent which comprises 2-10 wt% of sequestering agent as a complexing agent; 10-20 wt% of an alkaline material as a conditioning agent; 0.1-1 wt% of an accelerating agent as a reaction velocity improver; and the rest of water and which removes an oxidation film and a carbide film on a heat-affected zone of the welded surface of a painting target object to improve the performance of forming a phosphate coating layer so that the neutral detergent is applied to an existing continuous painting line without an additional process by improving the removal of an oxidation film and a carbide film even under a neutral or an alkalescent environment. In case of the dilution of the neutral detergent with a solvent, the pH of the neutral detergent is 6-10; the conductivity of the neutral detergent is 5-30 ms/cm; and the calcium deterrent power of the neutral detergent is 5-30 ml. In case of the neutralization titration of the neutral detergent with 0.1N-HaOH, a consumed amount of the neutral detergent is 0-4.9 ml. [Reference numerals] (AA) Section; (BB) Oxidation film eliminating capacity (exterior); (CC) CR normal steel sheet; (DD) Anticorrosive steel sheet; (EE) Steel grade; (FF) Phosphate coating layer forming capacity (SEM particle condition); (GG) Welding bead; (HH) 1 mm from the bead; (II) 5 mm from the bead; (JJ) Example of present invention; (KK) Example of an existing one