Use of Dithiophosphinic Acid and/or Its Salts for Producing Anti-Corrosion Coatings that are Devoid of Chrome

Abstract

Use of dithiophosphinic acids of the general formula HS 2 P(R 1 )(R 2 ) and/or salts thereof for producing chrome-free, polymer-containing corrosion control layers on metallic surfaces, R 1 and R 2 independently of one another each being organic radicals having 1 to 30 C atoms.

1 - 18 . (canceled) 
     
     
         19 . A process for applying a chrome-free corrosion control layer to a metallic surface comprising
 (1) applying to a metallic surface a layer of a radiation-crosslinkable formulation comprising
 (V) at least one crosslinkable component containing radiation-crosslinkable groups; 
 (V′) optionally at least one reactive diluent; 
 (C) optionally a pigment and/or filler; 
 (D) a corrosion preventative; and 
 (E) optionally a solvent; and 
   (2) crosslinking the applied layer by means of radiation;   wherein (D) comprises 0.25% to 10% by weight of at least one dithiophosphinic acid of the general formula HS 2 P(R 1 )(R 2 ) and/or a salt thereof, wherein R 1  and R 2  are, independently of one another, organic radicals having up to 30 C atoms, and wherein the radiation-crosslinkable groups comprise ethylenically unsaturated groups.   
     
     
         20 . The process of  claim 19 , wherein said radiation-crosslinkable groups are (meth)acrylate groups. 
     
     
         21 . The process of  claim 20 , wherein said at least one crosslinkable component is selected from the group consisting of polyfunctional (meth)acrylates, urethane (meth)acrylates, polyester (meth)acrylates, epoxy (meth)acrylates, carbonate (meth)acrylates, and polyether (meth)acrylates. 
     
     
         22 . The process of  claim 21 , wherein said at least one crosslinkable component comprises urethane (meth)acrylates. 
     
     
         23 . The process of  claim 22 , wherein said urethane (meth)acrylates have a mean (meth)acrylate functionality of from 2 to 10. 
     
     
         24 . The process of  claim 22 , wherein the urethane (meth)acrylates have a number-average molar mass M n  of from 500 g/mol to 20,000 g/mol. 
     
     
         25 . The process of  claim 19 , wherein said corrosion control layer has a thickness of from 1 to 25 μm. 
     
     
         26 . The process of  claim 19 , wherein said metallic surface is iron, steel, Zn, Zn alloys, Al, or Al alloys. 
     
     
         27 . The process of  claim 19 , wherein said metallic surface is the surface of a coil metal and application is carried out by means of a continuous process. 
     
     
         28 . A process for applying a chrome-free corrosion control layer to a metallic surface comprising
 (1) treating a metallic surface with a crosslinkable formulation comprising
 (A) a polymeric binder; 
 (B) crosslinkable components, which are optionally crosslinkable groups connected to said polymeric binder and/or can be at least one additionally employed crosslinker; 
 (C) optionally a pigment and/or filler; 
 (D) a corrosion preventative; and 
 (E) optionally a solvent; and 
   (2) thermally crosslinking the applied layer;   wherein (D) comprises 0.25% to 10% by weight of at least one dithiophosphinic acid of the general formula HS 2 P(R 1 )(R 2 ) and/or salt thereof, wherein R 1  and R 2  are, independently of one another, organic radicals having up to 30 C atoms, and wherein (A) is selected from the group consisting of (meth)acrylate (co)polymers, partially hydrolyzed polyvinyl esters, polyesters, alkyd resins, polylactones, polycarbonates, polyethers, epoxy resin-amine adducts, polyureas, polyamides, polyimides, or polyurethanes.   
     
     
         29 . The process of  claim 28 , wherein (A) is a polyester or an epoxy resin-amine adduct. 
     
     
         30 . The process of  claim 29 , wherein said thermal crosslinking is performed at 100 to 250° C. 
     
     
         31 . A process for applying a chrome-free corrosion control layer to a metallic surface comprising
 (1) treating a metallic surface with a formulation which is curable under atmospheric conditions and which comprises
 (A) a binder system curable under atmospheric conditions; 
 (C) optionally a pigment and/or filler; 
 (D) a corrosion preventative; and 
 (E) optionally a solvent; and 
   (2) curing the applied layer under atmospheric conditions;   wherein (D) comprises 0.25% to 10% by weight of at least one dithiophosphinic acid of the general formula HS 2 P(R 1 )(R 2 ) and/or a salt thereof, wherein R 1  and R 2  are, independently of one another, organic radicals having up to 30 C atoms, and wherein the binder system is at least one selected from the group consisting of aqueous or predominantly aqueous dispersions of polyacrylates and/or styrene-acrylate copolymers (A1), styrene-alkadiene polymers (A2), polyurethanes (A3) or alkyd resins (A4).   
     
     
         32 . The process of  claim 31 , wherein said corrosion control layer has a thickness of from 25 μm to 1 mm. 
     
     
         33 . The process of  claim 31 , wherein said binder system is an aqueous or predominantly aqueous dispersion of polyacrylates. 
     
     
         34 . The process of  claim 31 , wherein said binder system is an aqueous or predominantly aqueous dispersion of styrene-acrylate copolymers. 
     
     
         35 . The process of  claim 31 , wherein said binder system is an aqueous or predominantly aqueous dispersion of styrene-butadiene copolymers. 
     
     
         36 . The process of  claim 31 , wherein said surface is a metallic building or a metal construction.