Method and solution for coating metal surfaces with a posphating solution containing water peroxide, produced metal object and use of said object

Abstract

The invention relates to a method for the treatment or pre-treatment of surfaces of metal objects by means of an acidic, aqueous solution containing zinc and phosphate. Said invention is characterised in that the phosphating solution contains between 0.1-10 g/L zinc, 4-50 g/L phosphate calculated as PO 4 , between 0.03-3 g/L of at least one guanidine compound comprising at least one nitro group calculated as nitroguanidine, and between 0.001-0.9 g/L hydrogen peroxide and has a temperature of less than 80° C. The invention also relates to a corresponding acidic, aqueous composition.

1 - 26 . (canceled)  
   
   
       27 . A process for the treatment or pretreatment of surfaces of metallic objects with an acidic, aqueous solution containing zinc and phosphate, wherein the phosphating solution contains 
 0.1 to 10 g/l of zinc,    4 to 50 g/l of phosphate, calculated as PO 4 ,    0.03 to 3 g/l of at least one guanidine compound which contains at least one nitro group, calculated as nitroguanidine, and    0.001 to 0.9 g/l of hydrogen peroxide    and has a temperature of less than 80° C., wherein in a first step no calcium or magnesium are intenionally added.    
   
   
       28 . The process according to  claim 27 , wherein the contents in the phosphating solution of manganese are 0.1 to 10 g/l or/and of nickel 0.01 to 1.8 g/l.  
   
   
       29 . The process according to claim  1 , wherein the contents in the phosphating solution of Fe2+ are 0.005 to 1 g/l or/and of complexed Fe 3+  0.005 to 0.5 g/l.  
   
   
       30 . The process according to  claim 27 , wherein the contents in the phosphating solution of sodium are 0.04 to 20 g/l, of potassium 0.025 to 35 g/l, or/and of ammonium 0.01 to 50 g/l, where the total of sodium, potassium and ammonium is preferably 0.025 to 70 g/l.  
   
   
       31 . The process according to  claim 27 , wherein the contents in the phosphating solution of nitrate are 0.1 to 30 g/l, of chloride 0.01 to 0.5 g/l or/and of sulfate 0.005 to 5 g/l.  
   
   
       32 . The process according to  claim 27 , wherein the contents in the phosphating solution of dissolved aluminium, including complexed aluminium, are 0.002 to 1 g/l.  
   
   
       33 . The process according to  claim 27 , wherein the contents in the phosphating solution of copper are 0.002 to 0.05 g/l.  
   
   
       34 . The process according to  claim 27 , wherein the contents in the phosphating solution of free fluoride are 0.005 to 1 g/l or/and of total fluoride 0.005 to 6 g/l.  
   
   
       35 . The process according to  claim 27 , wherein the phosphating solution contains 0.005 to 5 g/l of complex fluoride.  
   
   
       36 . The process according to  claim 35 , wherein the contents in the phosphating solution of silicofluoride, calculated as SiF 6 , are 0.005 to 4.5 g/l or/and of boron fluoride, calculated as BF 4 , 0.005 to 4.5 g/l.  
   
   
       37 . The process according to  claim 27 , wherein the contents in the phosphating solution of titanium are 0.01 to 2 g/l or/and of zirconium 0.01 to 2 g/l.  
   
   
       38 . The process according to  claim 27 , wherein the phosphating solution has a content of at least 0.001 g/l of a water-soluble or/and water-dispersible organic polymeric compound.  
   
   
       39 . The process according to  claim 27 , wherein the phosphating solution contains 
 0.1 to 10 g/l of zinc,    optionally 0.1 to 10 g/l of manganese,    optionally 0.01 to 1.8 g/l of nickel,    0.025 to 70 g/l of sodium, potassium and ammonium together,    optionally 0.01 to 2 g/l of titanium or/and 0.01 to 2 g/l of zirconium,    4 to 50 g/l of phosphate, calculated as PO 4 ,    0.005 to 1 g/l of free fluoride,    0.005 to 6 g/l of total fluoride,    optionally 0.005 to 5 g/l of the total of complex fluorides of B, Si, Ti, Hf or/and Zr,    optionally 0.005 to 4.5 g/l of silicofluoride or/and 0.005 to 4.5 g/l of boron fluoride,    0.03 to 3 g/l of at least one guanidine compound which contains at least one nitro group, calculated as nitroguanidine,    0.001 to 0.9 g/l of hydrogen peroxide,    0.1 to 30 g/l of nitrate, optionally 0.01 to 0.5 g/l of chloride,    optionally 0.005 to 5 g/l of sulfate and    optionally 0.001 to 0.5 g/l of at least one water-soluble or/and water-dispersible organic polymeric compound.    
   
   
       40 . The process according to  claim 39 , wherein the phosphating solution contains 
 0.2 to 6 g/l of zinc    optionally 0.1 to 5 g/l of manganese,    optionally 0.01 to 1.6 g/l of nickel,    0.025 to 40 g/l of sodium, potassium and ammonium together,    optionally 0.01 to 2 g/l of titanium or/and 0.01 to 2 g/l of zirconium,    5 to 45 g/l of phosphate, calculated as PO 4 ,    0.005 to 1 g/l of free fluoride,    0.005 to 5 g/l of total fluoride,    optionally 0.005 to 4 g/l of the total of complex fluorides of B, Si, Ti, Hf or/and Zr,    optionally 0.005 to 3.6 g/l of silicofluoride or/and 0.005 to 3.6 g/l of boron fluoride,    0.03 to 2 g/l of at least one guanidine compound which contains at least one nitro group, calculated as nitroguanidine,    0.001 to 0.9 g/l of hydrogen peroxide,    0.1 to 20 g/l of nitrate,    optionally 0.01 to 0.5 g/l of chloride,    optionally 0.005 to 3 g/l of sulfate and    optionally 0.002 to 0.4 g/l of at least one water-soluble or/and water-dispersible organic polymeric compound.    
   
   
       41 . The process according to  claim 27 , wherein the S value as the ratio of the number of points of free acid KCl—or free acid—to the number of points of Fischer total acid is in the range from 0.01 to 0.40.  
   
   
       42 . The process according to  claim 27 , wherein the metallic surfaces are phosphated at a temperature in the range from 30 to 75° C.  
   
   
       43 . The process according to  claim 27 , wherein the metallic surface are brought into contact with the phosphating solution over a period of time in the range from 0.1 to 8 minutes, and in the case of rolling on or/and misting on using a belt also shorter contact times of down to fractions of a second.  
   
   
       44 . The process according to  claim 27 , wherein the metallic surfaces of a mix of objects of different metallic materials chosen from aluminium, aluminium alloy, steel, galvanized steel and zinc alloy are phosphated.  
   
   
       45 . The process according to  claim 27 , wherein the metallic surfaces are cleaned, pickled or/and activated, optionally in each case with a subsequent rinsing step, before the phosphating.  
   
   
       46 . The process according to  claim 27 , wherein the phosphated metallic surfaces are then rinsed, after-rinsed with an after-rinsing solution, dried or/and coated with in each case at least one lacquer, one lacquer-like coating, one adhesive or/and one foil.  
   
   
       47 . An acidic aqueous solution comprising. 
 0.l to 10 g/l of zinc,    4 to 50 g/l of phosphate, calculated as PO 4 ,    0.03 to 3 g/l of at least one guanidine compound which contains at least one nitro group, calculated as nitroguanidine,    and 0.001 to 0.9 g/l of hydrogen peroxide.    
   
   
       48 . The acidic, aqueous solution according to  claim 47 , further comprising 
 0.025 to 70 g/l of sodium, potassium and ammonium together,    0.005 to 1 g/l of free fluoride,    0.005 to 6 g/l of total fluoride or/and    0.1 to 30 g/l of nitrate.    
   
   
       49 . The acidic, aqueous solution according to  claim 47 , wherein it additionally also contains 
 0.1 to 10 g/l of manganese,    0.01 to 1.8 g/l of nickel,    0.005 to 5 g/l of the total of complex fluorides of B, Si, Ti, Hf or/and Zr,    0.005 to 4.5 g/l of silicofluoride,    0.005 to 4.5 g/l of boron fluoride,    0.01 to 2 g/l of titanium,    0.01 to 2 g/l of zirconium,    0.01 to 0.5 g/l of chloride,    0.005 to 5 g/l of sulfate or/and    optionally 0.001 to 0.5 g/l of at least one water-soluble or/and water-dispersible organic polymeric compound.    
   
   
       50 . A metallic object with a phosphate layer, which has been produced by the process according to  claim 27.