초록 ▼

Described is a process using a no-rinse technique for the production of a chromium-free conversion layer on the surface of aluminum and its alloys by treating with an aqueous solution having a pH between 1 and 3.5 and containing titanium and/or zirconium plus an organic film-forming agent. The proce

Described is a process using a no-rinse technique for the production of a chromium-free conversion layer on the surface of aluminum and its alloys by treating with an aqueous solution having a pH between 1 and 3.5 and containing titanium and/or zirconium plus an organic film-forming agent. The process is characterized in that the surface is brought into contact with a solution containing a) 2.2 to 22.0 g/l of Zr(IV) and/or 1.4 to 14.0 g/l of Ti(IV), b) 2.4 to 24.0 g/l of orthophosphate, c) 3.0 to 30.0 g/l of fluoride, d) 0.15 to 1.5 g/l of a water-soluble or homogeneously water-dispersible organic film former and, after a contact time between 1 and 40 seconds, the wet surface is allowed to dry, without rinsing, at a temperature between 50.degree. and 125.degree. C. Also described are aqueous concentrates for use in the process.

대표청구항 ▼

[ The invention claimed is:] [1.] A process for the production of a chromium-free conversion coating on a surface of aluminum or its alloys by a no-rinse process by treatment with an aqueous solution having a pH value of 1 to 3.5 and containing:a) 2.2 to 22.0 g/l of Zr(IV), 1.4 to 14.0 g/l of Ti(IV)

[ The invention claimed is:] [1.] A process for the production of a chromium-free conversion coating on a surface of aluminum or its alloys by a no-rinse process by treatment with an aqueous solution having a pH value of 1 to 3.5 and containing:a) 2.2 to 22.0 g/l of Zr(IV), 1.4 to 14.0 g/l of Ti(IV), or both,b) 2.4 to 24.0 g/l of orthophosphate,c) 3.0 to 30.0 g/l of fluoride, andd) 0.15 to 1.5 g/l of a water-soluble or homogeneously water-dispersible organic film former, wherein the solutions are, at temperatures of 50.degree. to 125.degree. C. dried on the surface without rinsing after a contact time of 1 to 40 seconds between said surface and said aqueous solution.