초록 ▼

The present invention relates to a process for phosphating metal surfaces, and more specifically of surfaces of iron, zinc, and aluminum and the alloys thereof as a pretreatment for cold working wherein the surfaces without previous activation are contacted in a temperature range of from 30°C. to 70

The present invention relates to a process for phosphating metal surfaces, and more specifically of surfaces of iron, zinc, and aluminum and the alloys thereof as a pretreatment for cold working wherein the surfaces without previous activation are contacted in a temperature range of from 30°C. to 70°C. with an aqueous solution containing (a) from 10 to 40 g/l of Ca2+ions, (b) from 10 to 40 g/l of Zn2+ions, (c) from 10 to 100 g/l of OP43-ions and, as accelerator, (d) from 10 to 100 g/l of NO3-ions and/or (e) from 0.1 to 2.0 g/l of organic nitro compounds, said solution exhibiting a pH value in the range of from 2.0 to 3.8 and a ratio of free acid to total acid of from 1:4 to 1:100.

대표청구항 ▼

In a process comprising cleaning and phosphating metal surfaces, the improvement wherein the surfaces without previous activation are contacted in a temperature range of from 30°C. to 70°C. with an aqueous solution consisting essentially of: (a) from about 10 to about 40 g/l of Ca2+ions, (b) from ab

In a process comprising cleaning and phosphating metal surfaces, the improvement wherein the surfaces without previous activation are contacted in a temperature range of from 30°C. to 70°C. with an aqueous solution consisting essentially of: (a) from about 10 to about 40 g/l of Ca2+ions, (b) from about 10 to about 40 g/l of Zn2+ions, (c) from about 10 to about 100 g/l of PO43-ions, (d) an accelerator selected from the group consisting of (i) about 10 to about 100 g/l of nitrate ions and (ii) about 0.1 to about 2.0 g/l of organic nitro compounds, (e) up to about 10 g/l of Ni2+ions, and (f) up to abut 10 g/l of simple, complex, or mixed simple and complex fluoride ions, said solution having a pH value in the range from about 2.0 to about 3.8, a ratio of free acid to total acid from about 1:4 to 1:100, and a ratio by weight of Zn+2 ions to Ca+2 ions of about 1:0.5 to about 1:1.5; said process producing on the metal surfaces a phosphate layer containing scholzite in an areal density between about 3 and about 9 g/m2.