公开(公告)号：US3682713A

公开(公告)日：1972-08-08

申请号：US3682713D

申请日：1970-06-25

Applicant: COLLARDIN GMBH GERHARD

Inventor： RIES CHRISTIAN ,  STOLZENFELS GUNTER

IPC: C23C22/34 ,  C23C22/68 ,  C23C22/73 ,  C23C22/83 ,  C23F7/00

CPC classification number: C23C22/68 ,  C23C22/34 ,  C23C22/83

Abstract: A PROCESS FOR APPLYING A PROTECTIVE COATING ON ALUMINUM, ZINC AND IRON UNDER SUBSTANTIALLY INDENTICAL OPERATING CONDITIONS WHICH CONSISTS ESSENTIALY OF APPLYING TO THE METAL SURFACES OF ALUMINUM, ZINC AND IRON OF A COMPLEX FLUORIDE COATING SOLUTION FREE FORM CHROMIC ACID, PHOSPHORIC ACID AND OXALIC ACID HAVING A CONCENTRATION OF FROM 0.1 TO 15 GM. PER LITER, BASED ON THE METAL CONTENT, OF COMPLEX FLUORIDES OF METALS SELECTED FROMTHE GROUP CONSISTING OF BORON, TITANIUM, ZIRCONIUM AND IRON, FROM 0.1 TO 10 GM. PER LITER OF FREE FLUOREDE IONS AND FROM 0.5 TO 30 GM. PER LITER, CALCULATED AS SODIUM M-NITROBENZENE SULFONATE, OF AN OXIDIZING AGENT, AT A PH OF FROM 3.0 TO 6.8 FOR A TIME SUFFICIENT TO FORM A COATING. THE APPLIED COATINGS CNA BE POST-PASSIVATED WITH SOLUTIONS CONTAINING CHROMIC OR PHOSPHOORIC ACIDS.