Method for Producing a Sandwich Structure, Sandwich Structure Produce Thereby and Use Thereof

Abstract

The invention relates to a method for producing a sandwich structure on the basis of at least one layer on the basis of metallic material and on the basis of at least one layer of organic polymer, wherein for coating of at least one metallic surface with at least one metallic layer to be combined with the layer on the basis of organic polymer, an aqueous conversion composition on the basis of zinc, additional cations, poly(acrylic acid), and optionally silane, is brought into contact, wherein the liquid film thereby produced is dried on and wherein the metallic layer coated in such manner is brought into contact with at least one layer on the basis of organic polymer and is combined into a sandwich structure by means of compaction under pressure and/or temperature. The invention also relates to such sandwich structures.

1 .- 16 . (canceled) 
     
     
         17 . A method for producing a sandwich structure on the basis of at least one layer of metallic material and on the basis of at least one layer of organic polymer, characterized in that at least one surface on at least one metallic layer which is to be combined with at least one layer of organic polymer is brought into contact with an aqueous conversion composition which contains:
 0.5 to 20 g/l zinc,   0.01 to 10 g/l manganese, 0.01 to 10 g/l aluminum, 0.01 to 1 g/l chromium(III), 0.01 to 5 g/l iron(II), 0.01 to 5 g/l iron(III) and/or 0.01 to 5 g/l magnesium,   0 or 0.01 to 5 g/l of the total as nickel and/or cobalt,   0 or 0.01 to 5 g/l of the total as molybdenum, tantalum, vanadium and/or tungsten,   2 to 100 g/l P 2 O 5 , which corresponds to 2.68 to 133.8 g/l PO 4 ,   0.1 to 10 g/l polyacrylic acid, but not more than 25% of the P 2 O 5  content of the composition in g/l, and   0 or 0.01 to 3 g/l silane, but not more than 25% of the P 2 O 5  content of the composition in g/l,   in that a liquid film produced therewith is dried on,   in that the metallic layer coated in this manner is cut, if required, and in that the metallic layer coated in this manner is brought into contact with at least one layer on the basis of organic polymer and is combined into a sandwich structure by means of compaction under pressure and/or temperature.   
     
     
         18 . The method according to  claim 17 , characterized in that the aqueous conversion composition has the following composition:
 1 to 10 g/l zinc,   0.5 to 6 g/l manganese, 0.01 to 0.5 g/l aluminum, 0.01 to 0.8 g/l chromium(III), 0.01 to 1 g/l iron(II), 0.01 to 1 g/l iron(III) and/or 0.01 to 1.5 g/l magnesium,   0 or 0.01 to 2.5 g/l nickel, 0 or 0.01 to 2.5 g/l cobalt, wherein the total of nickel and cobalt is 0 or lies in the range from 0.01 to 4 g/l,   0 or 0.01 to 5 g/l of the total as molybdenum, tantalum and/or vanadium,   8 to 60 g/l P 2 O 5 , which corresponds to 10.72 to 80.28 g/l PO 4 ,   0.5 to 5 g/l polyacrylic acid, but not more than 25% of the P 2 O 5  content of the composition in g/l, and   0 or 0.01 to 3 g/l silane, but not more than 25% of the P 2 O 5  content of the composition in g/l and also no content of a complex fluoride of titanium or zirconium.   
     
     
         19 . The method according to  claim 17 , characterized in that the aqueous conversion composition has the following composition:
 2 to 8 g/l zinc,   1 to 5 g/l manganese, 0.01 to 0.2 g/l aluminum, 0.01 to 0.5 g/l chromium(III), 0.01 to 0.5 g/l iron(II), 0.01 to 0.5 g/l iron(III) and/or 0.01 to 0.8 g/l magnesium,   0 or 0.01 to 2 g/l nickel,   0 or 0.01 to 2 g/l cobalt, wherein the total of nickel and cobalt is not more than 2.5 g/l,   0 or 0.01 to 5 g/l of the total as molybdenum, and/or vanadium,   9.5 to 50 g/l P 2 O 5 , which corresponds to 12.73 to 66.9 g/l PO 4 ,   0.5 to 3 g/l polyacrylic acid, but not more than 25% of the P 2 O 5  content of the composition in g/l, and   0 or 0.01 to 2 g/l silane, but not more than 25% of the P 2 O 5  content of the composition in g/l and also no content of a complex fluoride of titanium or zirconium.   
     
     
         20 . The method according to  claim 17 , characterized in that the method takes place without an activation step with a colloidal titanium phosphate or with a surface conditioner on the basis of phosphate particles. 
     
     
         21 . The method according to  claim 17 , characterized in that a wet film of the aqueous conversion composition is homogeneously formed on the metallic surface and that the contact time with the aqueous conversion composition until complete drying on is less than 1 minute. 
     
     
         22 . The method according to  claim 17 , characterized in that the liquid film thereby produced is dried on without being rinsed herein or hereafter with aqueous liquid. 
     
     
         23 . The method according to  claim 17 , characterized in that a conversion coating with a layer weight of up to 0.4 g/m 2  is formed. 
     
     
         24 . The method according to  claim 23 , characterized in that the conversion coating is formed in the form of a microphosphating. 
     
     
         25 . The method according to  claim 23 , characterized in that the conversion coating is formed largely or entirely amorphous. 
     
     
         26 . The method according to  claim 17 , characterized in that the at least one layer is made of organic thermoplastic polymer which is optionally fiber-reinforced. 
     
     
         27 . The method according to  claim 17 , characterized in that the at least one layer of organic polymer is a polymer on the basis of polyamide, polyethylene and/or polypropylene, which is optionally made of thermoplastic plastics and/or is also fiber-reinforced. 
     
     
         28 . A sandwich structure produced with a method according to  claim 17 . 
     
     
         29 . The sandwich structure according to  claim 28 , characterized in that the content of polyacrylic acid and/or its reaction products in the dried-on and/or the dried-on and, during compaction, thermally loaded, conversion coating is 0.05 to 15% by weight of the conversion coating. 
     
     
         30 . The sandwich structure according to  claim 28 , characterized in that the content of at least one silane and/or its/their reaction products in the dried-on and/or the dried-on and, during compaction, thermally loaded conversion coating is 0.01 to 15% by weight of the conversion coating. 
     
     
         31 . The sandwich structure according to  claim 28 , characterized in that it is at least once respectively coated, deformed, glued, compressed and/or otherwise joined. 
     
     
         32 . Use of the sandwich structure according to  claim 28 . 
     
     
         33 . Use of the sandwich structure produced in accordance with the method according to the  claim 17  in motor vehicle construction, in aircraft construction, in space travel, in apparatus construction, in machine construction, in building construction, in furniture production or as structural elements.