Method for producing coated metal surfaces and the use of said metal surfaces

Abstract

The invention relates to a method for producing coated metal surfaces at a coating speed of at least 25 m per minute during the application of a pre-treating agent to a cleaned and/or pickled metal surface. The inventive method is characterized by applying at least one pre-treating agent to at least one surface of a metal body after cleaning and/or pickling the metal surface to be treated. At least one lacquer layer is applied to a part of the pre-treated surface, the coating produced only by the pre-treating agent and not by the lacquer being used as the treatment layer instead of a priming or pre-treatment layer. The invention further relates to a method for producing coated metal surfaces at a coating speed of at least 25 m per minute during the application of a pre-treating agent to a cleaned and/or pickled metal surface. The inventive method is characterized by applying at least one pre-treating agent to at least one surface of a metal body after cleaning and/or pickling the metal surface to be treated. At least one lacquer layer is applied to at least a part of the pre-treated surface, the coating produced only by the pre-treating agent being used as the treatment layer instead of a priming or pre-treatment layer.

1 . Method for producing coated metal surfaces at a coating speed of at least 25 m per minute in the application of at least one pretreatment agent to a cleaned and/or pickled metal surface of a metal strip, characterised in that 
 at least one pretreatment agent is applied to at least one side of the strip after a cleaning and/or a pickling of the metal surface to be treated and at least one lacquer layer is then applied to at least a part of the pretreated surface, in particular on one side of the strip,    the coating produced with a pretreatment agent and not with a lacquer is used, instead of a priming and pretreatment layer, as treatment layer, with the side of the strip not intended to be subsequently lacquered being preferably coated with a pretreatment agent containing an organic resin,    the side of the strip intended to be subsequently lacquered being coated with at least one pretreatment agent, preferably with a pretreatment agent that is different to that used for the side of the strip not intended to be subsequently lacquered, and    the at least one lacquer layer being applied as powder lacquer to the pretreated side of the strip intended to be subsequently lacquered, and is stoved.    
     
     
         2 . Method according to  claim 1 , characterised in that the moisture or residual moisture in the applied pretreatment layer is retained until the lacquering in order to adjust the necessary electrical conductivity of the pretreated surface for the application of the lacquer layer.  
     
     
         3 . Method according to  claim 1  or  2 , characterised in that the metal surface contains before the pretreatment aluminium, iron, copper, magnesium, zinc and/or tin and preferably consists of an aluminium alloy, a hot-dip galvanised or electrolytically galvanised iron material, a steel, or a full zinc material in the form of strips.  
     
     
         4 . Method according to one of the preceding claims, characterised in that the cleaning and/or the pickling is carried out by spraying and/or brushing with a cleaning and/or pickling solution or immersion in a bath of this solution.  
     
     
         5 . Method according to one of the preceding claims, characterised in that the pretreatment agent is applied by spraying and squeezing out with a roller or by immersion and squeezing out with a roller or by a roll-coat process.  
     
     
         6 . Method according to one of the preceding claims, characterised in that the pretreatment agent is a preparation that contains a polymer dispersion with at least one resin from the group consisting of acrylate, epoxide, phenol, polyester, silicone polyester, polyurethane, styrene and urea-formaldehyde based resin or a mixture thereof and/or a mixed polymer.  
     
     
         7 . Method according to one of the preceding claims, characterised in that the pretreatment agent is a preparation that contains at least one resin in the form of a solution and/or dispersion.  
     
     
         8 . Method according to one of the preceding claims, characterised in that the pretreatment agent is a preparation that contains, apart from resin(s), at least one inorganic additive in dissolved form and/or as finely divided powder, for example a carbonate, chromate, oxide, phosphate, silicate or sulfate.  
     
     
         9 . Method according to one of the preceding claims, characterised in that the pretreatment agent is a resin-free preparation that contains aluminium, fluoride, hydrofluoric acid, phosphate, phosphoric acid, trivalent and/or hexavalent chromate, chromic acid, silicate, self-organising molecules, silane, tannin, titanium, zinc and/or zirconium.  
     
     
         10 . Method according to one of the preceding claims, characterised in that, for the application to a strip a pretreatment agent is selected for one side of the strip that is different to that selected for the other side, with it being possible for the side that is not intended to be subsequently lacquered to be coated with a pretreatment agent containing organic resin.  
     
     
         11 . Method according to  claim 5 , characterised in that the layer applied with the pretreatment agent is either partially dried or completely dried.  
     
     
         12 . Method according to one of the preceding claims, characterised in that at least one side of the pretreated surface is coated with an organic coating that hardens and/or crosslinks sufficiently in a time of 1 second up to 3 minutes, preferably in a time of 5 seconds up to 2 minutes.  
     
     
         13 . Method according to  claim 12 , characterised in that, for the coating of the pretreated surface, a powder lacquer having good mechanical properties, high scratch resistance, good adhesion and high flexibility with regard to forming and shaping is applied and stoved.  
     
     
         14 . Method according to one of the preceding claims, characterised in that the powder lacquer is applied by spraying, fluidised-bed powder sintering and/or powder cloud technology and stoved.  
     
     
         15 . Method according to one of the preceding claims, characterised in that, after complete drying, the pretreatment layer and/or treatment layer has a layer thickness in the range from 0.1 to 50 μm, preferably in the range from 0.5 to 10 μm, particularly preferably in the range from 1 to 3 μm.  
     
     
         16 . Method according to one of the preceding claims, characterised in that the stoved lacquer layer after the crosslinking has a layer thickness in the range from 5 to 1000 μm, preferably in the range from 10 to 400 μm, particularly preferably in the range from 15 to 60 μm.  
     
     
         17 . Method according to one of the preceding claims, characterised in that a single-layer cover lacquer is applied as sole lacquer at high speed.  
     
     
         18 . Method according to one of the preceding claims, characterised in that a treatment layer that performs the function of a pretreatment and primer is formed with the pre-treatment agent.  
     
     
         19 . Method according to one of the preceding claims, characterised in that a powder for a single-colour unstructured coating, a powder for a multicolour unstructured coating, and/or a powder for a multicolour structured coating is used.  
     
     
         20 . Method according to one of the preceding claims, characterised in that the coated surface is protected at least partially by a film or adhesive film.  
     
     
         21 . Method according to one of the preceding claims, characterised in that the coated bodies are optionally shaped or formed, cut—especially in the longitudinal and/or transverse direction—and optionally reformed, for example beaded, roll-formed, deep-drawn and/or edged.  
     
     
         22 . Use of the products produced by the method according to  claims 1  to  21  as internal and external panelling, equipment panelling, e.g. for domestic appliances and small electrical instruments, in particular with decorated external panelling, perforated metal sheets, especially for loudspeakers and sound insulating cladding, space dividers, partitions, furniture units, shelving, internal panelling for vehicles and aircraft, such as for example dashboards/instrument panels, frame and frame constructions, facing materials and lighting installations.