62results about How to "Short passivation time" patented technology

The invention discloses a chromium-free passivating agent for a galvanized plate and a preparation process thereof. The chromium-free passivating agent for a galvanized plate uses organosilane as a main component and comprises the following raw materials by weight: in terms of 1 L of the passivating agent, 15 to 20 g / L of organosilane, 6 to 10 g / L of sulfosalicylic acid, 3 to 5 g / L of an auxiliary film forming agent, 1 to 3 g / L of sodium fluoride, 1 to 5 g / L of sodium molybdate, 0.3 to 0.6 g / L of a rare-earth salt, 0.1 to 0.3 g / L of sodium silicate and a small amount of a pH adjusting agent, with the balance being water. The surface conditioning agent, i.e., the chromium-free passivating agent, has the advantages of capacity of performing passivation at normal temperature, a short passivation time, greenness, environment friendliness and no inclusion of hexavalent chromium heavy metal ions; and a compact three-dimensional reticular passive film formed by the chromium-free passivating agent substantially improves corrosion resistance of galvanized plates and has excellent coating binding force at the same time. The preparation process for the chromium-free passivating agent is simple and is convenient for practical production.

The invention discloses a chromium-free passivation method of an aluminum pipe for an evaporator of a refrigerator or a freezer and a passivation solution thereof, belonging to the technical field of surface treatment of aluminum materials. The invention aims to improve the corrosion resistance of the aluminum pipe for the evaporator and the like of the refrigerator or the freezer. A passivation process is carried out on a CANFORM continuous extrusion aluminum pipe production line in an on-line way, the aluminum pipe formed by CANFORM continuous extrusion passes through a passivation groove after being water-cooled, and the passivation solution which has the components of passivator, assistant and solvent is filled into the groove, wherein vinyltris(beta-methoxyethoxy)silane the mass concentration of which is 1-15% is used as the passivator I, and dodecyl phosphate the mass concentration of which is 0.2-0.5% is used as the passivator II; benzotriazole or sodium silicate the concentration of which is 0.01-0.3% is used as the assistant; the mixture of water and 95% ethanol, the concentration of which is 3-8%, is used as the solvent; the passivation pH is 1.5-3.5, the passivation temperature is 35-50 DEG C, and the passivation time is 1-15 seconds; and the passivated aluminum pipe is packed with a rotating disk after being aired at 40-100 DEG C. The invention has the advantages of simple technical processes, low cost, high speed, on-line passivation, great improvement of corrosion resistance of the passivated aluminum pipe, and safety and environmental protection of medicaments and passivation processes.