Process for the coating of metallic components with an aqueous organic composition

Abstract

The invention relates to a process for the coating of surfaces of a metallic component to be formed by at least one forming operation like cold-forming, cold-forging, roll-stamping, roll-forming, deep-drawing or wire-drawing by contacting the surfaces of the metallic component before the forming operation with an aqueous composition that contains predominantly organic polymeric material whereby the aqueous composition contains at least one compound each of: A) organic film-forming polymeric material(s) selected from the group consisting of ionomeric copolymers, copolymers chemically related to ionomeric copolymers showing nearly or totally the properties of ionomeric copolymers and their corresponding monomers, comonomers, oligomers, cooligomers, polymers, blockcopolymers as well as their esters, salts and derivates, which all together are constituents of at least 80% by weight of the total organic polymeric material and whereby the total organic polymeric material has an average acid number in the range from 20 to 300, A′) optionally at least one further organic film-forming polymer or their corresponding monomer(s), oligomer(s), copolymer(s), blockcopolymer(s), their derivates or any combination of them that do not belong to A) participating in the rest of the total organic polymeric material to 100% by weight, B) optionally neutralizing agent(s), C) low temperature corrosion inhibiting cross-linking agent(s) and D) water, whereby the pH of the aqueous composition is at the beginning of the coating process in the range from 6 to 10.5.

1 . A process for the coating of surfaces of a metallic component to be formed by at least one forming operation like cold-forming, cold-forging, roll-stamping, roll-forming, deep-drawing or wire-drawing by contacting the surfaces of the metallic component before the forming operation with an aqueous composition that contains predominantly organic polymeric material whereby the aqueous composition contains at least one compound each of: 
 A) organic film-forming polymeric material(s) selected from the group consisting of ionomeric copolymers, copolymers chemically related to ionomeric copolymers showing nearly or totally the properties of ionomeric copolymers and their corresponding monomers, comonomers, oligomers, cooligomers, polymers, blockcopolymers as well as their esters, salts and derivates,    which all together are constituents of at least 70% by weight of the total organic polymeric material and    whereby the total organic polymeric material has an average acid number in the range from 20 to 300,    A′) optionally at least one further organic film-forming polymer or their corresponding monomer(s), oligomer(s), copolymer(s), blockcopolymer(s), their derivates or any combination of them that do not belong to A) participating in the rest of the total organic polymeric material to 100% by weight,    B) optionally neutralizing agent(s),    C) low temperature corrosion inhibiting cross-linking agent(s) and    D) water,    whereby the pH of the aqueous composition is at the beginning of the coating process in the range from 6 to 10.5.    
   
   
       2 . The process for the coating of surfaces of a metallic component as claimed in  claim 1  whereby the ionomeric or nearly ionomeric copolymeric organic film-forming polymer(s) A) are selected from the group consisting of materials containing predominantly ethylene/propylene acrylic acid copolymers, ethylene/propylene methacrylic acid copolymers, ethylene/propylene maleic anhydride copolymers or ethylene/propylene naphthalic anhydride copolymers, their corresponding monomers, comonomers, oligomers, cooligomers, polymers, blockcopolymers as well as their corresponding esters, salts and derivates and any combination of these.  
   
   
       3 . The process for the coating of surfaces of a metallic component as claimed in  claim 1  whereby the aqueous composition or the organic ionomeric or nearly ionomeric polymeric material or any combination thereof for the aqueous composition is prepared by heating up an aqueous polymeric base composition containing at least one of the organic polymeric materials having an acid number in the range from 50 to 250 and at least one neutralizing agent to temperatures in the range from 50 to 150° C. for a time of at least half a minute whereby at least one organic polymeric material is neutralized, then by cooling and moving the composition which has then a pH in the range from 6 to 10.5.  
   
   
       4 . The process for the coating of surfaces of a metallic component as claimed in  claim 1  whereby the at least one neutralizing agent B) for the organic polymeric material is selected from the group consisting of ammonia and of any other volatile alkaline neutralizer.  
   
   
       5 . The process for the coating of surfaces of a metallic component as claimed in  claim 1  whereby the at least one low temperature corrosion inhibiting cross-linking agents C) is selected from the group consisting of compounds of lithium, sodium, potassium, rubidium, cesium, calcium, magnesium, strontium, barium, yttrium, titanium, hafnium, zirconium, manganese, iron, cobalt, nickel, copper, zinc, niobium, molybdenum, boron, silicon like a silane/silanol/siloxane/polysiloxane, phosphorus and at least one lanthanide containing compounds.  
   
   
       6 . The process for the coating of surfaces of a metallic component as claimed in  claim 1  whereby the low temperature corrosion inhibiting cross-linking agents C) complex a chemical group of organic film-forming polymeric material(s) and cause the insolubility of the organic polymeric material(s) after drying.  
   
   
       7 . The process for the coating of surfaces of a metallic component as claimed in  claim 1  whereby the low temperature corrosion inhibiting cross-linking agents C) contain particles, nanoparticles, gels, sols or any combination of these of inorganic materials like oxides, hydroxides, carbonates, water-insoluble sulfates, silicates or any combination thereof.  
   
   
       8 . The process for the coating of surfaces of a metallic component as claimed in  claim 1  whereby the low temperature corrosion inhibiting cross-linking agents C) are blocked.  
   
   
       9 . The process for the coating of surfaces of a metallic component as claimed in  claim 1  whereby there is further added to the aqueous composition at least one constituent selected from the group consisting of: 
 a) acidic catalyst(s),    b) rheology controlling agent(s),    c) wetting agent(s),    d) adhesion promoting agent(s),    e) film-forming agent(s),    f) defoaming agent(s),    g) UV absorber(s), light stabilizer(s) or both,    h) further agent(s) like photoinitiators, like antioxidants, like dyes, like coloring pigments as well as like other types of cross-linkers and    j) organic solvent(s).    
   
   
       10 . The process for the coating of surfaces of a metallic component as claimed in  claim 1  whereby the aqueous composition contains at least one chromium compound selected from the group consisting of chromates and dichromates of ammonium, lithium, sodium and potassium.  
   
   
       11 . The process for the coating of surfaces of a metallic component as claimed in  claim 1  whereby the coating generated with the aqueous composition has the function of a pretreatment primer.  
   
   
       12 . The process for the coating of surfaces of a metallic component as claimed in  claim 1  whereby the aqueous composition as well as the composition of the drying film or of the dried film are such that the cross-linking of the organic polymeric material may be performed at a temperature in the range from 5 to 85° C.  
   
   
       13 . The process for the coating of surfaces of a metallic component as claimed in  claim 1  whereby the coating is dried at a temperature below 65° C.  
   
   
       14 . The process for the coating of surfaces of a metallic component as claimed in  claim 1  whereby the aqueous composition contains at least one other type of cross-linker and whereby the generated coating is further cross-linked starting at low or high temperature.  
   
   
       15 . The process for the coating of surfaces of a metallic component as claimed in  claim 1  whereby the coating contains at least one other type of cross-linker and whereby the generated coating is further cross-linked starting with a temperhardening or with another kind of heating.  
   
   
       16 . The process for the coating of surfaces of a metallic component as claimed in  claim 1  whereby the aqueous composition contains at least one photoinitiator and actinically cross-linkable monomers and whereby the generated coating is further cross-linked starting by actinic irradiation.  
   
   
       17 . The process for the coating of surfaces of a metallic component as claimed in  claim 1  whereby the coating generated with the aqueous composition is afterwards coated with at least one layer each of a primer, a powder paint, a base coat, a clear coat, an adhesive or any combination of these.  
   
   
       18 . The process for the coating of surfaces of a metallic component as claimed in  claim 1  whereby there is further applied a coating from a composition containing at least one forming agent like any oil or wax or both on the coating prepared with the aqueous composition as claimed in  claim 1  whereby the such coated metallic component may be used for a heavy forming operation like deep-drawing.  
   
   
       19 . The process for the coating of surfaces of a metallic component as claimed in  claim 1  whereby the coating generated with the aqueous composition is joined by the aid of at least one adhesive with any paper, any foil, any sheet or any other part.  
   
   
       20 . A coating generated with a process as claimed in  claim 1 .  
   
   
       21 . A coated metallic component coated by a process as claimed in  claim 1 .  
   
   
       22 . A method of use of a metallic component coated by a process as claimed in  claim 1  for corrugated iron, gutters, profiles, tubings, automotive stampings, housings, electronic equipment, guard rails, inside or outside architectural use, aerospace industry, automotive industry, apparatuses, appliance industry, construction, roofing, siding, transport, ventilating, cylinders, fasteners, shafts, containers or tanks.